DBD-SQLcipher
view release on metacpan or search on metacpan
return TRUE;
#else
sqlite_error(dbh, SQLITE_ERROR, form("backup feature requires SQLcipher 3.6.11 and newer"));
return FALSE;
#endif
}
typedef struct perl_tokenizer {
sqlite3_tokenizer base;
SV *coderef; /* the perl tokenizer is a coderef that takes
a string and returns a cursor coderef */
} perl_tokenizer;
typedef struct perl_tokenizer_cursor {
sqlite3_tokenizer_cursor base;
SV *coderef; /* ref to the closure that returns terms */
char *pToken; /* storage for a copy of the last token */
int nTokenAllocated; /* space allocated to pToken buffer */
/* members below are only used if the input string is in utf8 */
const char *pInput; /* input we are tokenizing */
const char *lastByteOffset; /* offset into pInput */
int lastCharOffset; /* char offset corresponding to lastByteOffset */
} perl_tokenizer_cursor;
/*
** Create a new tokenizer instance.
** Will be called whenever a FTS3 table is created with
** CREATE .. USING fts3( ... , tokenize=perl qualified::function::name)
** where qualified::function::name is a fully qualified perl function
*/
static int perl_tokenizer_Create(
int argc, const char * const *argv,
sqlite3_tokenizer **ppTokenizer
sv_free(t->coderef);
sqlite3_free(t);
return SQLITE_OK;
}
/*
** Prepare to begin tokenizing a particular string. The input
** string to be tokenized is supposed to be pInput[0..nBytes-1] ..
** except that nBytes passed by fts3 is -1 (don't know why) !
** This is passed to the tokenizer instance, which then returns a
** closure implementing the cursor (so the cursor is again a coderef).
*/
static int perl_tokenizer_Open(
sqlite3_tokenizer *pTokenizer, /* Tokenizer object */
const char *pInput, int nBytes, /* Input buffer */
sqlite3_tokenizer_cursor **ppCursor /* OUT: Created tokenizer cursor */
){
dTHX;
dSP;
dMY_CXT;
U32 flags;
SV *perl_string;
int n_retval;
perl_tokenizer *t = (perl_tokenizer *)pTokenizer;
/* allocate and initialize the cursor struct */
perl_tokenizer_cursor *c;
c = (perl_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));
memset(c, 0, sizeof(*c));
*ppCursor = &c->base;
/* flags for creating the Perl SV containing the input string */
flags = SVs_TEMP; /* will call sv_2mortal */
/* special handling if working with utf8 strings */
if (MY_CXT.last_dbh_is_unicode) {
/* data to keep track of byte offsets */
}
perl_string = newSVpvn_flags(pInput, nBytes, flags);
/* call the tokenizer coderef */
PUSHMARK(SP);
XPUSHs(perl_string);
PUTBACK;
n_retval = call_sv(t->coderef, G_SCALAR);
SPAGAIN;
/* store the cursor coderef returned by the tokenizer */
if (n_retval != 1) {
warn("tokenizer returned %d arguments", n_retval);
}
c->coderef = newSVsv(POPs);
PUTBACK;
FREETMPS;
LEAVE;
return SQLITE_OK;
}
/*
** Close a tokenization cursor previously opened by a call to
** perl_tokenizer_Open() above.
*/
static int perl_tokenizer_Close(sqlite3_tokenizer_cursor *pCursor){
perl_tokenizer_cursor *c = (perl_tokenizer_cursor *) pCursor;
dTHX;
sv_free(c->coderef);
if (c->pToken) sqlite3_free(c->pToken);
sqlite3_free(c);
return SQLITE_OK;
}
/*
** Extract the next token from a tokenization cursor. The cursor must
** have been opened by a prior call to perl_tokenizer_Open().
*/
static int perl_tokenizer_Next(
sqlite3_tokenizer_cursor *pCursor, /* Cursor returned by perl_tokenizer_Open */
const char **ppToken, /* OUT: *ppToken is the token text */
int *pnBytes, /* OUT: Number of bytes in token */
int *piStartOffset, /* OUT: Starting offset of token */
int *piEndOffset, /* OUT: Ending offset of token */
int *piPosition /* OUT: Position integer of token */
){
perl_tokenizer_cursor *c = (perl_tokenizer_cursor *) pCursor;
int result;
int n_retval;
char *token;
char *byteOffset;
STRLEN n_a; /* this is required for older perls < 5.8.8 */
I32 hop;
dTHX;
dSP;
ENTER;
SAVETMPS;
/* call the cursor */
PUSHMARK(SP);
PUTBACK;
n_retval = call_sv(c->coderef, G_ARRAY);
SPAGAIN;
/* if we get back an empty list, there is no more token */
if (n_retval == 0) {
result = SQLITE_DONE;
}
/* otherwise, get token details from the return list */
else {
if (n_retval != 5) {
warn("tokenizer cursor returned %d arguments", n_retval);
}
*piPosition = POPi;
*piEndOffset = POPi;
*piStartOffset = POPi;
*pnBytes = POPi;
token = POPpx;
if (c->pInput) { /* if working with utf8 data */
/* recompute *pnBytes in bytes, not in chars */
/* make sure we have enough storage for copying the token */
if (*pnBytes > c->nTokenAllocated ){
char *pNew;
c->nTokenAllocated = *pnBytes + 20;
pNew = sqlite3_realloc(c->pToken, c->nTokenAllocated);
if( !pNew ) return SQLITE_NOMEM;
c->pToken = pNew;
}
/* need to copy the token into the C cursor before perl frees that
memory */
memcpy(c->pToken, token, *pnBytes);
*ppToken = c->pToken;
result = SQLITE_OK;
}
PUTBACK;
FREETMPS;
LEAVE;
** The set of routines that implement the perl "module"
** (i.e support for virtual tables written in Perl)
************************************************************************/
typedef struct perl_vtab {
sqlite3_vtab base;
SV *perl_vtab_obj;
HV *functions;
} perl_vtab;
typedef struct perl_vtab_cursor {
sqlite3_vtab_cursor base;
SV *perl_cursor_obj;
} perl_vtab_cursor;
typedef struct perl_vtab_init {
SV *dbh;
const char *perl_class;
} perl_vtab_init;
/* auxiliary routine for generalized method calls. Arg "i" may be unused */
static int _call_perl_vtab_method(sqlite3_vtab *pVTab,
PUTBACK;
FREETMPS;
LEAVE;
return SQLITE_OK;
}
static int perl_vt_Open(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
dTHX;
dSP;
int count;
int rc = SQLITE_ERROR;
SV *perl_cursor;
perl_vtab_cursor *cursor;
ENTER;
SAVETMPS;
/* allocate a perl_vtab_cursor structure */
cursor = (perl_vtab_cursor *) sqlite3_malloc(sizeof(*cursor));
if( cursor==NULL ) return SQLITE_NOMEM;
memset(cursor, 0, sizeof(*cursor));
/* call the ->OPEN() method */
PUSHMARK(SP);
XPUSHs( ((perl_vtab *) pVTab)->perl_vtab_obj);
PUTBACK;
count = call_method ("OPEN", G_SCALAR);
SPAGAIN;
if (count != 1) {
warn("vtab->OPEN() method returned %d vals instead of 1", count);
SP -= count;
goto cleanup;
}
perl_cursor = POPs;
if ( !sv_isobject(perl_cursor) ) {
warn("vtab->OPEN() method did not return a blessed cursor");
goto cleanup;
}
/* everything went OK */
rc = SQLITE_OK;
cleanup:
if (rc == SQLITE_OK) {
cursor->perl_cursor_obj = SvREFCNT_inc(perl_cursor);
*ppCursor = &cursor->base;
}
else {
sqlite3_free(cursor);
}
PUTBACK;
FREETMPS;
LEAVE;
return rc;
}
static int perl_vt_Close(sqlite3_vtab_cursor *pVtabCursor){
dTHX;
dSP;
perl_vtab_cursor *perl_pVTabCursor;
ENTER;
SAVETMPS;
/* Note : there is no explicit call to a CLOSE() method; if
needed, the Perl class can implement a DESTROY() method */
perl_pVTabCursor = (perl_vtab_cursor *) pVtabCursor;
SvREFCNT_dec(perl_pVTabCursor->perl_cursor_obj);
sqlite3_free(perl_pVTabCursor);
PUTBACK;
FREETMPS;
LEAVE;
return SQLITE_OK;
}
static int perl_vt_Filter( sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv ){
dTHX;
dSP;
dMY_CXT;
int i, count;
int is_unicode = MY_CXT.last_dbh_is_unicode;
ENTER;
SAVETMPS;
/* call the FILTER() method with ($idxNum, $idxStr, @args) */
PUSHMARK(SP);
XPUSHs(((perl_vtab_cursor *) pVtabCursor)->perl_cursor_obj);
XPUSHs(sv_2mortal(newSViv(idxNum)));
XPUSHs(sv_2mortal(newSVpv(idxStr, 0)));
for(i = 0; i < argc; i++) {
XPUSHs(stacked_sv_from_sqlite3_value(aTHX_ argv[i], is_unicode));
}
PUTBACK;
count = call_method("FILTER", G_VOID);
SPAGAIN;
SP -= count;
PUTBACK;
FREETMPS;
LEAVE;
return SQLITE_OK;
}
static int perl_vt_Next(sqlite3_vtab_cursor *pVtabCursor){
dTHX;
dSP;
int count;
ENTER;
SAVETMPS;
/* call the next() method */
PUSHMARK(SP);
XPUSHs(((perl_vtab_cursor *) pVtabCursor)->perl_cursor_obj);
PUTBACK;
count = call_method ("NEXT", G_VOID);
SPAGAIN;
SP -= count;
PUTBACK;
FREETMPS;
LEAVE;
return SQLITE_OK;
}
static int perl_vt_Eof(sqlite3_vtab_cursor *pVtabCursor){
dTHX;
dSP;
int count, eof;
ENTER;
SAVETMPS;
/* call the eof() method */
PUSHMARK(SP);
XPUSHs(((perl_vtab_cursor *) pVtabCursor)->perl_cursor_obj);
PUTBACK;
count = call_method ("EOF", G_SCALAR);
SPAGAIN;
if (count != 1) {
warn("cursor->EOF() method returned %d vals instead of 1", count);
SP -= count;
}
else {
SV *sv = POPs; /* need 2 lines, because this doesn't work : */
eof = SvTRUE(sv); /* eof = SvTRUE(POPs); # I don't understand why :-( */
}
PUTBACK;
FREETMPS;
LEAVE;
return eof;
}
static int perl_vt_Column(sqlite3_vtab_cursor *pVtabCursor,
sqlite3_context* context,
int col){
dTHX;
dSP;
int count;
int rc = SQLITE_ERROR;
ENTER;
SAVETMPS;
/* call the column() method */
PUSHMARK(SP);
XPUSHs(((perl_vtab_cursor *) pVtabCursor)->perl_cursor_obj);
XPUSHs(sv_2mortal(newSViv(col)));
PUTBACK;
count = call_method ("COLUMN", G_SCALAR);
SPAGAIN;
if (count != 1) {
warn("cursor->COLUMN() method returned %d vals instead of 1", count);
SP -= count;
sqlite3_result_error(context, "column error", 12);
}
else {
SV *result = POPs;
sqlite_set_result(aTHX_ context, result, 0 );
rc = SQLITE_OK;
}
PUTBACK;
FREETMPS;
LEAVE;
return rc;
}
static int perl_vt_Rowid( sqlite3_vtab_cursor *pVtabCursor,
sqlite3_int64 *pRowid ){
dTHX;
dSP;
int count;
int rc = SQLITE_ERROR;
ENTER;
SAVETMPS;
/* call the rowid() method */
PUSHMARK(SP);
XPUSHs(((perl_vtab_cursor *) pVtabCursor)->perl_cursor_obj);
PUTBACK;
count = call_method ("ROWID", G_SCALAR);
SPAGAIN;
if (count != 1) {
warn("cursor->ROWID() returned %d vals instead of 1", count);
SP -= count;
}
else {
*pRowid =POPi;
rc = SQLITE_OK;
}
PUTBACK;
FREETMPS;
LEAVE;
/* call the _SQLITE_UPDATE() method */
PUSHMARK(SP);
XPUSHs(((perl_vtab *) pVTab)->perl_vtab_obj);
for(i = 0; i < argc; i++) {
XPUSHs(stacked_sv_from_sqlite3_value(aTHX_ argv[i], is_unicode));
}
PUTBACK;
count = call_method ("_SQLITE_UPDATE", G_SCALAR);
SPAGAIN;
if (count != 1) {
warn("cursor->_SQLITE_UPDATE() returned %d vals instead of 1", count);
SP -= count;
}
else {
if (argc > 1 && sqlite3_value_type(argv[0]) == SQLITE_NULL
&& sqlite3_value_type(argv[1]) == SQLITE_NULL) {
/* this was an insert without any given rowid, so the result of
the method call must be passed in *pRowid*/
rowidsv = POPs;
if (!SvOK(rowidsv))
*pRowid = 0;
return _call_perl_vtab_method(pVTab, "ROLLBACK_TO", point);
}
static sqlite3_module perl_vt_Module = {
1, /* iVersion */
perl_vt_Create, /* xCreate */
perl_vt_Connect, /* xConnect */
perl_vt_BestIndex, /* xBestIndex */
perl_vt_Disconnect, /* xDisconnect */
perl_vt_Drop, /* xDestroy */
perl_vt_Open, /* xOpen - open a cursor */
perl_vt_Close, /* xClose - close a cursor */
perl_vt_Filter, /* xFilter - configure scan constraints */
perl_vt_Next, /* xNext - advance a cursor */
perl_vt_Eof, /* xEof - check for end of scan */
perl_vt_Column, /* xColumn - read data */
perl_vt_Rowid, /* xRowid - read data */
perl_vt_Update, /* xUpdate (optional) */
perl_vt_Begin, /* xBegin (optional) */
perl_vt_Sync, /* xSync (optional) */
perl_vt_Commit, /* xCommit (optional) */
perl_vt_Rollback, /* xRollback (optional) */
perl_vt_FindFunction, /* xFindFunction (optional) */
perl_vt_Rename, /* xRename */
fts3_tokenizer.h view on Meta::CPAN
** Defines the interface to tokenizers used by fulltext-search. There
** are three basic components:
**
** sqlite3_tokenizer_module is a singleton defining the tokenizer
** interface functions. This is essentially the class structure for
** tokenizers.
**
** sqlite3_tokenizer is used to define a particular tokenizer, perhaps
** including customization information defined at creation time.
**
** sqlite3_tokenizer_cursor is generated by a tokenizer to generate
** tokens from a particular input.
*/
#ifndef _FTS3_TOKENIZER_H_
#define _FTS3_TOKENIZER_H_
/* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.
** If tokenizers are to be allowed to call sqlite3_*() functions, then
** we will need a way to register the API consistently.
*/
fts3_tokenizer.h view on Meta::CPAN
** functions that make up an implementation.
**
** When an fts3 table is created, it passes any arguments passed to
** the tokenizer clause of the CREATE VIRTUAL TABLE statement to the
** sqlite3_tokenizer_module.xCreate() function of the requested tokenizer
** implementation. The xCreate() function in turn returns an
** sqlite3_tokenizer structure representing the specific tokenizer to
** be used for the fts3 table (customized by the tokenizer clause arguments).
**
** To tokenize an input buffer, the sqlite3_tokenizer_module.xOpen()
** method is called. It returns an sqlite3_tokenizer_cursor object
** that may be used to tokenize a specific input buffer based on
** the tokenization rules supplied by a specific sqlite3_tokenizer
** object.
*/
typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
typedef struct sqlite3_tokenizer sqlite3_tokenizer;
typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
struct sqlite3_tokenizer_module {
/*
** Structure version. Should always be set to 0 or 1.
*/
int iVersion;
/*
** Create a new tokenizer. The values in the argv[] array are the
fts3_tokenizer.h view on Meta::CPAN
sqlite3_tokenizer **ppTokenizer /* OUT: Created tokenizer */
);
/*
** Destroy an existing tokenizer. The fts3 module calls this method
** exactly once for each successful call to xCreate().
*/
int (*xDestroy)(sqlite3_tokenizer *pTokenizer);
/*
** Create a tokenizer cursor to tokenize an input buffer. The caller
** is responsible for ensuring that the input buffer remains valid
** until the cursor is closed (using the xClose() method).
*/
int (*xOpen)(
sqlite3_tokenizer *pTokenizer, /* Tokenizer object */
const char *pInput, int nBytes, /* Input buffer */
sqlite3_tokenizer_cursor **ppCursor /* OUT: Created tokenizer cursor */
);
/*
** Destroy an existing tokenizer cursor. The fts3 module calls this
** method exactly once for each successful call to xOpen().
*/
int (*xClose)(sqlite3_tokenizer_cursor *pCursor);
/*
** Retrieve the next token from the tokenizer cursor pCursor. This
** method should either return SQLITE_OK and set the values of the
** "OUT" variables identified below, or SQLITE_DONE to indicate that
** the end of the buffer has been reached, or an SQLite error code.
**
** *ppToken should be set to point at a buffer containing the
** normalized version of the token (i.e. after any case-folding and/or
** stemming has been performed). *pnBytes should be set to the length
** of this buffer in bytes. The input text that generated the token is
** identified by the byte offsets returned in *piStartOffset and
** *piEndOffset. *piStartOffset should be set to the index of the first
fts3_tokenizer.h view on Meta::CPAN
**
** The buffer *ppToken is set to point at is managed by the tokenizer
** implementation. It is only required to be valid until the next call
** to xNext() or xClose().
*/
/* TODO(shess) current implementation requires pInput to be
** nul-terminated. This should either be fixed, or pInput/nBytes
** should be converted to zInput.
*/
int (*xNext)(
sqlite3_tokenizer_cursor *pCursor, /* Tokenizer cursor */
const char **ppToken, int *pnBytes, /* OUT: Normalized text for token */
int *piStartOffset, /* OUT: Byte offset of token in input buffer */
int *piEndOffset, /* OUT: Byte offset of end of token in input buffer */
int *piPosition /* OUT: Number of tokens returned before this one */
);
/***********************************************************************
** Methods below this point are only available if iVersion>=1.
*/
/*
** Configure the language id of a tokenizer cursor.
*/
int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);
};
struct sqlite3_tokenizer {
const sqlite3_tokenizer_module *pModule; /* The module for this tokenizer */
/* Tokenizer implementations will typically add additional fields */
};
struct sqlite3_tokenizer_cursor {
sqlite3_tokenizer *pTokenizer; /* Tokenizer for this cursor. */
/* Tokenizer implementations will typically add additional fields */
};
int fts3_global_term_cnt(int iTerm, int iCol);
int fts3_term_cnt(int iTerm, int iCol);
#endif /* _FTS3_TOKENIZER_H_ */
/************** End of fts3_tokenizer.h **************************************/
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
};
return $outputs;
}
sub OPEN {
my $self = shift;
my $class = ref $self;
my $cursor_class = $class . "::Cursor";
return $cursor_class->NEW($self, @_);
}
#----------------------------------------------------------------------
# methods for insert/delete/update
#----------------------------------------------------------------------
sub _SQLITE_UPDATE {
my ($self, $old_rowid, $new_rowid, @values) = @_;
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
sub NEW {
my ($class, $vtable, @args) = @_;
my $self = {vtable => $vtable,
args => \@args};
bless $self, $class;
}
sub FILTER {
my ($self, $idxNum, $idxStr, @values) = @_;
die "FILTER() should be redefined in cursor subclass";
}
sub EOF {
my ($self) = @_;
die "EOF() should be redefined in cursor subclass";
}
sub NEXT {
my ($self) = @_;
die "NEXT() should be redefined in cursor subclass";
}
sub COLUMN {
my ($self, $idxCol) = @_;
die "COLUMN() should be redefined in cursor subclass";
}
sub ROWID {
my ($self) = @_;
die "ROWID() should be redefined in cursor subclass";
}
1;
__END__
=head1 NAME
DBD::SQLcipher::VirtualTable -- SQLcipher virtual tables implemented in Perl
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
=over
=item *
the B<table> class implements methods for creating or connecting
a virtual table, for destroying it, for opening new searches, etc.
=item *
the B<cursor> class implements methods for performing a specific
SQL statement
=back
=head2 Methods
Most methods in both classes are not called directly from Perl
code : instead, they are callbacks, called from the sqlite kernel.
Following common Perl conventions, such methods have names in
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
that will be used
=over
=item a)
by the sqlite kernel to decide about the best search strategy
=item b)
by the cursor L</FILTER> method to produce the desired subset
of rows from the virtual table.
=back
By calling this method, the SQLcipher core is saying to the virtual table
that it needs to access some subset of the rows in the virtual table
and it wants to know the most efficient way to do that access. The
C<BEST_INDEX> method replies with information that the SQLcipher core can
then use to conduct an efficient search of the virtual table.
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
The C<$constraints> arrayref is used both for input and for output.
While iterating over the array, the method should
add the following keys into usable constraints :
=over
=item C<argvIndex>
An index into the C<@values> array that will be passed to
the cursor's L</FILTER> method. In other words, if the current
constraint corresponds to the SQL fragment C<WHERE ... AND foo < 123 ...>,
and the corresponding C<argvIndex> takes value 5, this means that
the C<FILTER> method will receive C<123> in C<$values[5]>.
=item C<omit>
A boolean telling to the sqlite core that it can safely omit
to double check that constraint before returning the resultset
to the calling program; this means that the FILTER method has fulfilled
the filtering job on that constraint and there is no need to do any
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
=item C<estimatedRows>
An integer giving the estimated number of rows returned by that query.
=back
=head3 OPEN
Called to instanciate a new cursor.
The default implementation appends C<"::Cursor"> to the current
classname and calls C<NEW()> within that cursor class.
=head3 _SQLITE_UPDATE
This is the dispatch method implementing the C<xUpdate()> callback
for virtual tables. The default implementation applies the algorithm
described in L<http://sqlite.org/vtab.html#xupdate> to decide
to call L</INSERT>, L</DELETE> or L</UPDATE>; so there is no reason
to override this method in subclasses.
=head3 INSERT
lib/DBD/SQLcipher/VirtualTable.pm view on Meta::CPAN
This method returns the database handle (C<$dbh>) associated with
the current virtual table.
=head1 CURSOR METHODS
=head2 Class methods
=head3 NEW
my $cursor = $cursor_class->NEW($vtable, @args)
Instanciates a new cursor.
The default implementation just returns a blessed hashref
with keys C<vtable> and C<args>.
=head2 Instance methods
=head3 FILTER
$cursor->FILTER($idxNum, $idxStr, @values);
This method begins a search of a virtual table.
The C<$idxNum> and C<$idxStr> arguments correspond to values returned
by L</BEST_INDEX> for the chosen index. The specific meanings of
those values are unimportant to SQLcipher, as long as C<BEST_INDEX> and
C<FILTER> agree on what that meaning is.
The C<BEST_INDEX> method may have requested the values of certain
expressions using the C<argvIndex> values of the
C<$constraints> list. Those values are passed to C<FILTER> through
the C<@values> array.
If the virtual table contains one or more rows that match the search
criteria, then the cursor must be left point at the first
row. Subsequent calls to L</EOF> must return false. If there are
no rows match, then the cursor must be left in a state that will cause
L</EOF> to return true. The SQLcipher engine will use the
L</COLUMN> and L</ROWID> methods to access that row content. The L</NEXT>
method will be used to advance to the next row.
=head3 EOF
This method must return false if the cursor currently points to a
valid row of data, or true otherwise. This method is called by the SQL
engine immediately after each L</FILTER> and L</NEXT> invocation.
=head3 NEXT
This method advances the cursor to the next row of a
result set initiated by L</FILTER>. If the cursor is already pointing at
the last row when this method is called, then the cursor no longer
points to valid data and a subsequent call to the L</EOF> method must
return true. If the cursor is successfully advanced to
another row of content, then subsequent calls to L</EOF> must return
false.
=head3 COLUMN
my $value = $cursor->COLUMN($idxCol);
The SQLcipher core invokes this method in order to find the value for the
N-th column of the current row. N is zero-based so the first column is
numbered 0.
=head3 ROWID
my $value = $cursor->ROWID;
Returns the I<rowid> of row that the cursor is currently pointing at.
=head1 SEE ALSO
L<SQLcipher::VirtualTable> is another module for virtual tables written
in Perl, but designed for the reverse use case : instead of starting a
Perl program, and embedding the SQLcipher library into it, the intended
use is to start an sqlite program, and embed the Perl interpreter
into it.
lib/DBD/SQLcipher/VirtualTable/PerlData.pm view on Meta::CPAN
# build a method coderef to fetch matching rows
my $perl_code = 'sub {my ($self, $i) = @_; my $row = $self->row($i); '
. $idxStr
. '}';
# print STDERR "PERL CODE:\n", $perl_code, "\n";
$self->{is_wanted_row} = do { no warnings; eval $perl_code }
or die "couldn't eval q{$perl_code} : $@";
# position the cursor to the first matching row (or to eof)
$self->{row_ix} = -1;
$self->NEXT;
}
sub EOF {
my ($self) = @_;
return $self->{row_ix} > $#${$self->{vtable}{rows}};
}
**
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
*/
/*
** Structures used by the virtual table interface
*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;
/*
** CAPI3REF: Virtual Table Object
** KEYWORDS: sqlite3_module {virtual table module}
**
** This structure, sometimes called a "virtual table module",
** defines the implementation of a [virtual tables].
** This structure consists mostly of methods for the module.
**
int iVersion;
int (*xCreate)(sqlite3*, void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVTab, char**);
int (*xConnect)(sqlite3*, void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVTab, char**);
int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
int (*xDisconnect)(sqlite3_vtab *pVTab);
int (*xDestroy)(sqlite3_vtab *pVTab);
int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
int (*xClose)(sqlite3_vtab_cursor*);
int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
int argc, sqlite3_value **argv);
int (*xNext)(sqlite3_vtab_cursor*);
int (*xEof)(sqlite3_vtab_cursor*);
int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
int (*xBegin)(sqlite3_vtab *pVTab);
int (*xSync)(sqlite3_vtab *pVTab);
int (*xCommit)(sqlite3_vtab *pVTab);
int (*xRollback)(sqlite3_vtab *pVTab);
int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
void **ppArg);
int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
/* The methods above are in version 1 of the sqlite_module object. Those
*/
struct sqlite3_vtab {
const sqlite3_module *pModule; /* The module for this virtual table */
int nRef; /* NO LONGER USED */
char *zErrMsg; /* Error message from sqlite3_mprintf() */
/* Virtual table implementations will typically add additional fields */
};
/*
** CAPI3REF: Virtual Table Cursor Object
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
**
** Every [virtual table module] implementation uses a subclass of the
** following structure to describe cursors that point into the
** [virtual table] and are used
** to loop through the virtual table. Cursors are created using the
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
** by the [sqlite3_module.xClose | xClose] method. Cursors are used
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
** of the module. Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
sqlite3_vtab *pVtab; /* Virtual table of this cursor */
/* Virtual table implementations will typically add additional fields */
};
/*
** CAPI3REF: Declare The Schema Of A Virtual Table
**
** ^The [xCreate] and [xConnect] methods of a
** [virtual table module] call this interface
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
** Values that may be OR'd together to form the second argument of an
** sqlite3BtreeCursorHints() call.
*/
#define BTREE_BULKLOAD 0x00000001
SQLITE_PRIVATE int sqlite3BtreeCursor(
Btree*, /* BTree containing table to open */
int iTable, /* Index of root page */
int wrFlag, /* 1 for writing. 0 for read-only */
struct KeyInfo*, /* First argument to compare function */
BtCursor *pCursor /* Space to write cursor structure */
);
SQLITE_PRIVATE int sqlite3BtreeCursorSize(void);
SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
BtCursor*,
UnpackedRecord *pUnKey,
i64 intKey,
int bias,
typedef struct VdbeOp VdbeOp;
/*
** A sub-routine used to implement a trigger program.
*/
struct SubProgram {
VdbeOp *aOp; /* Array of opcodes for sub-program */
int nOp; /* Elements in aOp[] */
int nMem; /* Number of memory cells required */
int nCsr; /* Number of cursors required */
int nOnce; /* Number of OP_Once instructions */
void *token; /* id that may be used to recursive triggers */
SubProgram *pNext; /* Next sub-program already visited */
};
/*
** A smaller version of VdbeOp used for the VdbeAddOpList() function because
** it takes up less space.
*/
struct VdbeOpList {
#define OP_MakeRecord 49 /* synopsis: r[P3]=mkrec(r[P1@P2]) */
#define OP_Count 50 /* synopsis: r[P2]=count() */
#define OP_ReadCookie 51
#define OP_SetCookie 52
#define OP_ReopenIdx 53 /* synopsis: root=P2 iDb=P3 */
#define OP_OpenRead 54 /* synopsis: root=P2 iDb=P3 */
#define OP_OpenWrite 55 /* synopsis: root=P2 iDb=P3 */
#define OP_OpenAutoindex 56 /* synopsis: nColumn=P2 */
#define OP_OpenEphemeral 57 /* synopsis: nColumn=P2 */
#define OP_SorterOpen 58
#define OP_SequenceTest 59 /* synopsis: if( cursor[P1].ctr++ ) pc = P2 */
#define OP_OpenPseudo 60 /* synopsis: P3 columns in r[P2] */
#define OP_Close 61
#define OP_SeekLT 62 /* synopsis: key=r[P3@P4] */
#define OP_SeekLE 63 /* synopsis: key=r[P3@P4] */
#define OP_SeekGE 64 /* synopsis: key=r[P3@P4] */
#define OP_SeekGT 65 /* synopsis: key=r[P3@P4] */
#define OP_Seek 66 /* synopsis: intkey=r[P2] */
#define OP_NoConflict 67 /* synopsis: key=r[P3@P4] */
#define OP_NotFound 68 /* synopsis: key=r[P3@P4] */
#define OP_Found 69 /* synopsis: key=r[P3@P4] */
#define OP_NotExists 70 /* synopsis: intkey=r[P3] */
#define OP_Or 71 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */
#define OP_And 72 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */
#define OP_Sequence 73 /* synopsis: r[P2]=cursor[P1].ctr++ */
#define OP_NewRowid 74 /* synopsis: r[P2]=rowid */
#define OP_Insert 75 /* synopsis: intkey=r[P3] data=r[P2] */
#define OP_IsNull 76 /* same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
#define OP_NotNull 77 /* same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
#define OP_Ne 78 /* same as TK_NE, synopsis: if r[P1]!=r[P3] goto P2 */
#define OP_Eq 79 /* same as TK_EQ, synopsis: if r[P1]==r[P3] goto P2 */
#define OP_Gt 80 /* same as TK_GT, synopsis: if r[P1]>r[P3] goto P2 */
#define OP_Le 81 /* same as TK_LE, synopsis: if r[P1]<=r[P3] goto P2 */
#define OP_Lt 82 /* same as TK_LT, synopsis: if r[P1]<r[P3] goto P2 */
#define OP_Ge 83 /* same as TK_GE, synopsis: if r[P1]>=r[P3] goto P2 */
** be set. An INTEGER PRIMARY KEY is used as the rowid for each row of
** the table. If a table has no INTEGER PRIMARY KEY, then a random rowid
** is generated for each row of the table. TF_HasPrimaryKey is set if
** the table has any PRIMARY KEY, INTEGER or otherwise.
**
** Table.tnum is the page number for the root BTree page of the table in the
** database file. If Table.iDb is the index of the database table backend
** in sqlite.aDb[]. 0 is for the main database and 1 is for the file that
** holds temporary tables and indices. If TF_Ephemeral is set
** then the table is stored in a file that is automatically deleted
** when the VDBE cursor to the table is closed. In this case Table.tnum
** refers VDBE cursor number that holds the table open, not to the root
** page number. Transient tables are used to hold the results of a
** sub-query that appears instead of a real table name in the FROM clause
** of a SELECT statement.
*/
struct Table {
char *zName; /* Name of the table or view */
Column *aCol; /* Information about each column */
Index *pIndex; /* List of SQL indexes on this table. */
Select *pSelect; /* NULL for tables. Points to definition if a view. */
FKey *pFKey; /* Linked list of all foreign keys in this table */
**
** Expr.x.pList is a list of arguments if the expression is an SQL function,
** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
** Expr.x.pSelect is used if the expression is a sub-select or an expression of
** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
** valid.
**
** An expression of the form ID or ID.ID refers to a column in a table.
** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
** the integer cursor number of a VDBE cursor pointing to that table and
** Expr.iColumn is the column number for the specific column. If the
** expression is used as a result in an aggregate SELECT, then the
** value is also stored in the Expr.iAgg column in the aggregate so that
** it can be accessed after all aggregates are computed.
**
** If the expression is an unbound variable marker (a question mark
** character '?' in the original SQL) then the Expr.iTable holds the index
** number for that variable.
**
** If the expression is a subquery then Expr.iColumn holds an integer
} x;
/* If the EP_Reduced flag is set in the Expr.flags mask, then no
** space is allocated for the fields below this point. An attempt to
** access them will result in a segfault or malfunction.
*********************************************************************/
#if SQLITE_MAX_EXPR_DEPTH>0
int nHeight; /* Height of the tree headed by this node */
#endif
int iTable; /* TK_COLUMN: cursor number of table holding column
** TK_REGISTER: register number
** TK_TRIGGER: 1 -> new, 0 -> old
** EP_Unlikely: 134217728 times likelihood */
ynVar iColumn; /* TK_COLUMN: column index. -1 for rowid.
** TK_VARIABLE: variable number (always >= 1). */
i16 iAgg; /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
i16 iRightJoinTable; /* If EP_FromJoin, the right table of the join */
u8 op2; /* TK_REGISTER: original value of Expr.op
** TK_COLUMN: the value of p5 for OP_Column
** TK_AGG_FUNCTION: nesting depth */
int regReturn; /* Register holding return address of addrFillSub */
int regResult; /* Registers holding results of a co-routine */
u8 jointype; /* Type of join between this able and the previous */
unsigned notIndexed :1; /* True if there is a NOT INDEXED clause */
unsigned isCorrelated :1; /* True if sub-query is correlated */
unsigned viaCoroutine :1; /* Implemented as a co-routine */
unsigned isRecursive :1; /* True for recursive reference in WITH */
#ifndef SQLITE_OMIT_EXPLAIN
u8 iSelectId; /* If pSelect!=0, the id of the sub-select in EQP */
#endif
int iCursor; /* The VDBE cursor number used to access this table */
Expr *pOn; /* The ON clause of a join */
IdList *pUsing; /* The USING clause of a join */
Bitmask colUsed; /* Bit N (1<<N) set if column N of pTab is used */
char *zIndex; /* Identifier from "INDEXED BY <zIndex>" clause */
Index *pIndex; /* Index structure corresponding to zIndex, if any */
} a[1]; /* One entry for each identifier on the list */
};
/*
** Permitted values of the SrcList.a.jointype field
/*
** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
** and the WhereInfo.wctrlFlags member.
*/
#define WHERE_ORDERBY_NORMAL 0x0000 /* No-op */
#define WHERE_ORDERBY_MIN 0x0001 /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX 0x0002 /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED 0x0004 /* Want to do one-pass UPDATE/DELETE */
#define WHERE_DUPLICATES_OK 0x0008 /* Ok to return a row more than once */
#define WHERE_OMIT_OPEN_CLOSE 0x0010 /* Table cursors are already open */
#define WHERE_FORCE_TABLE 0x0020 /* Do not use an index-only search */
#define WHERE_ONETABLE_ONLY 0x0040 /* Only code the 1st table in pTabList */
/* 0x0080 // not currently used */
#define WHERE_GROUPBY 0x0100 /* pOrderBy is really a GROUP BY */
#define WHERE_DISTINCTBY 0x0200 /* pOrderby is really a DISTINCT clause */
#define WHERE_WANT_DISTINCT 0x0400 /* All output needs to be distinct */
#define WHERE_SORTBYGROUP 0x0800 /* Support sqlite3WhereIsSorted() */
#define WHERE_REOPEN_IDX 0x1000 /* Try to use OP_ReopenIdx */
/* Allowed return values from sqlite3WhereIsDistinct()
** Store the first column of the first result row
** in register pDest->iSDParm then abandon the rest
** of the query. This destination implies "LIMIT 1".
**
** SRT_Set The result must be a single column. Store each
** row of result as the key in table pDest->iSDParm.
** Apply the affinity pDest->affSdst before storing
** results. Used to implement "IN (SELECT ...)".
**
** SRT_EphemTab Create an temporary table pDest->iSDParm and store
** the result there. The cursor is left open after
** returning. This is like SRT_Table except that
** this destination uses OP_OpenEphemeral to create
** the table first.
**
** SRT_Coroutine Generate a co-routine that returns a new row of
** results each time it is invoked. The entry point
** of the co-routine is stored in register pDest->iSDParm
** and the result row is stored in pDest->nDest registers
** starting with pDest->iSdst.
**
u8 nested; /* Number of nested calls to the parser/code generator */
u8 nTempReg; /* Number of temporary registers in aTempReg[] */
u8 isMultiWrite; /* True if statement may modify/insert multiple rows */
u8 mayAbort; /* True if statement may throw an ABORT exception */
u8 hasCompound; /* Need to invoke convertCompoundSelectToSubquery() */
u8 okConstFactor; /* OK to factor out constants */
int aTempReg[8]; /* Holding area for temporary registers */
int nRangeReg; /* Size of the temporary register block */
int iRangeReg; /* First register in temporary register block */
int nErr; /* Number of errors seen */
int nTab; /* Number of previously allocated VDBE cursors */
int nMem; /* Number of memory cells used so far */
int nSet; /* Number of sets used so far */
int nOnce; /* Number of OP_Once instructions so far */
int nOpAlloc; /* Number of slots allocated for Vdbe.aOp[] */
int iFixedOp; /* Never back out opcodes iFixedOp-1 or earlier */
int ckBase; /* Base register of data during check constraints */
int iPartIdxTab; /* Table corresponding to a partial index */
int iCacheLevel; /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
int iCacheCnt; /* Counter used to generate aColCache[].lru values */
int nLabel; /* Number of labels used */
int *aLabel; /* Space to hold the labels */
struct yColCache {
int iTable; /* Table cursor number */
i16 iColumn; /* Table column number */
u8 tempReg; /* iReg is a temp register that needs to be freed */
int iLevel; /* Nesting level */
int iReg; /* Reg with value of this column. 0 means none. */
int lru; /* Least recently used entry has the smallest value */
} aColCache[SQLITE_N_COLCACHE]; /* One for each column cache entry */
ExprList *pConstExpr;/* Constant expressions */
Token constraintName;/* Name of the constraint currently being parsed */
yDbMask writeMask; /* Start a write transaction on these databases */
yDbMask cookieMask; /* Bitmask of schema verified databases */
** Bitfield flags for P5 value in various opcodes.
*/
#define OPFLAG_NCHANGE 0x01 /* Set to update db->nChange */
#define OPFLAG_EPHEM 0x01 /* OP_Column: Ephemeral output is ok */
#define OPFLAG_LASTROWID 0x02 /* Set to update db->lastRowid */
#define OPFLAG_ISUPDATE 0x04 /* This OP_Insert is an sql UPDATE */
#define OPFLAG_APPEND 0x08 /* This is likely to be an append */
#define OPFLAG_USESEEKRESULT 0x10 /* Try to avoid a seek in BtreeInsert() */
#define OPFLAG_LENGTHARG 0x40 /* OP_Column only used for length() */
#define OPFLAG_TYPEOFARG 0x80 /* OP_Column only used for typeof() */
#define OPFLAG_BULKCSR 0x01 /* OP_Open** used to open bulk cursor */
#define OPFLAG_P2ISREG 0x02 /* P2 to OP_Open** is a register number */
#define OPFLAG_PERMUTE 0x01 /* OP_Compare: use the permutation */
/*
* Each trigger present in the database schema is stored as an instance of
* struct Trigger.
*
* Pointers to instances of struct Trigger are stored in two ways.
* 1. In the "trigHash" hash table (part of the sqlite3* that represents the
* database). This allows Trigger structures to be retrieved by name.
struct Walker {
int (*xExprCallback)(Walker*, Expr*); /* Callback for expressions */
int (*xSelectCallback)(Walker*,Select*); /* Callback for SELECTs */
void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
Parse *pParse; /* Parser context. */
int walkerDepth; /* Number of subqueries */
u8 eCode; /* A small processing code */
union { /* Extra data for callback */
NameContext *pNC; /* Naming context */
int n; /* A counter */
int iCur; /* A cursor number */
SrcList *pSrcList; /* FROM clause */
struct SrcCount *pSrcCount; /* Counting column references */
} u;
};
/* Forward declarations */
SQLITE_PRIVATE int sqlite3WalkExpr(Walker*, Expr*);
SQLITE_PRIVATE int sqlite3WalkExprList(Walker*, ExprList*);
SQLITE_PRIVATE int sqlite3WalkSelect(Walker*, Select*);
SQLITE_PRIVATE int sqlite3WalkSelectExpr(Walker*, Select*);
/*
** The in-memory image of a disk page has the auxiliary information appended
** to the end. EXTRA_SIZE is the number of bytes of space needed to hold
** that extra information.
*/
#define EXTRA_SIZE sizeof(MemPage)
/*
** A linked list of the following structures is stored at BtShared.pLock.
** Locks are added (or upgraded from READ_LOCK to WRITE_LOCK) when a cursor
** is opened on the table with root page BtShared.iTable. Locks are removed
** from this list when a transaction is committed or rolled back, or when
** a btree handle is closed.
*/
struct BtLock {
Btree *pBtree; /* Btree handle holding this lock */
Pgno iTable; /* Root page of table */
u8 eLock; /* READ_LOCK or WRITE_LOCK */
BtLock *pNext; /* Next in BtShared.pLock list */
};
** this structure.
**
** For some database files, the same underlying database cache might be
** shared between multiple connections. In that case, each connection
** has it own instance of this object. But each instance of this object
** points to the same BtShared object. The database cache and the
** schema associated with the database file are all contained within
** the BtShared object.
**
** All fields in this structure are accessed under sqlite3.mutex.
** The pBt pointer itself may not be changed while there exists cursors
** in the referenced BtShared that point back to this Btree since those
** cursors have to go through this Btree to find their BtShared and
** they often do so without holding sqlite3.mutex.
*/
struct Btree {
sqlite3 *db; /* The database connection holding this btree */
BtShared *pBt; /* Sharable content of this btree */
u8 inTrans; /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
u8 sharable; /* True if we can share pBt with another db */
u8 locked; /* True if db currently has pBt locked */
int wantToLock; /* Number of nested calls to sqlite3BtreeEnter() */
int nBackup; /* Number of backup operations reading this btree */
** 2) The number of locks held by other connections drops to zero.
**
** while in the 'pending-lock' state, no connection may start a new
** transaction.
**
** This feature is included to help prevent writer-starvation.
*/
struct BtShared {
Pager *pPager; /* The page cache */
sqlite3 *db; /* Database connection currently using this Btree */
BtCursor *pCursor; /* A list of all open cursors */
MemPage *pPage1; /* First page of the database */
u8 openFlags; /* Flags to sqlite3BtreeOpen() */
#ifndef SQLITE_OMIT_AUTOVACUUM
u8 autoVacuum; /* True if auto-vacuum is enabled */
u8 incrVacuum; /* True if incr-vacuum is enabled */
u8 bDoTruncate; /* True to truncate db on commit */
#endif
u8 inTransaction; /* Transaction state */
u8 max1bytePayload; /* Maximum first byte of cell for a 1-byte payload */
u16 btsFlags; /* Boolean parameters. See BTS_* macros below */
** this will be declared corrupt. This value is calculated based on a
** maximum database size of 2^31 pages a minimum fanout of 2 for a
** root-node and 3 for all other internal nodes.
**
** If a tree that appears to be taller than this is encountered, it is
** assumed that the database is corrupt.
*/
#define BTCURSOR_MAX_DEPTH 20
/*
** A cursor is a pointer to a particular entry within a particular
** b-tree within a database file.
**
** The entry is identified by its MemPage and the index in
** MemPage.aCell[] of the entry.
**
** A single database file can be shared by two more database connections,
** but cursors cannot be shared. Each cursor is associated with a
** particular database connection identified BtCursor.pBtree.db.
**
** Fields in this structure are accessed under the BtShared.mutex
** found at self->pBt->mutex.
**
** skipNext meaning:
** eState==SKIPNEXT && skipNext>0: Next sqlite3BtreeNext() is no-op.
** eState==SKIPNEXT && skipNext<0: Next sqlite3BtreePrevious() is no-op.
** eState==FAULT: Cursor fault with skipNext as error code.
*/
struct BtCursor {
Btree *pBtree; /* The Btree to which this cursor belongs */
BtShared *pBt; /* The BtShared this cursor points to */
BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */
struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
Pgno *aOverflow; /* Cache of overflow page locations */
CellInfo info; /* A parse of the cell we are pointing at */
i64 nKey; /* Size of pKey, or last integer key */
void *pKey; /* Saved key that was cursor last known position */
Pgno pgnoRoot; /* The root page of this tree */
int nOvflAlloc; /* Allocated size of aOverflow[] array */
int skipNext; /* Prev() is noop if negative. Next() is noop if positive.
** Error code if eState==CURSOR_FAULT */
u8 curFlags; /* zero or more BTCF_* flags defined below */
u8 eState; /* One of the CURSOR_XXX constants (see below) */
u8 hints; /* As configured by CursorSetHints() */
i16 iPage; /* Index of current page in apPage */
u16 aiIdx[BTCURSOR_MAX_DEPTH]; /* Current index in apPage[i] */
MemPage *apPage[BTCURSOR_MAX_DEPTH]; /* Pages from root to current page */
};
/*
** Legal values for BtCursor.curFlags
*/
#define BTCF_WriteFlag 0x01 /* True if a write cursor */
#define BTCF_ValidNKey 0x02 /* True if info.nKey is valid */
#define BTCF_ValidOvfl 0x04 /* True if aOverflow is valid */
#define BTCF_AtLast 0x08 /* Cursor is pointing ot the last entry */
#define BTCF_Incrblob 0x10 /* True if an incremental I/O handle */
/*
** Potential values for BtCursor.eState.
**
** CURSOR_INVALID:
** Cursor does not point to a valid entry. This can happen (for example)
**
** CURSOR_VALID:
** Cursor points to a valid entry. getPayload() etc. may be called.
**
** CURSOR_SKIPNEXT:
** Cursor is valid except that the Cursor.skipNext field is non-zero
** indicating that the next sqlite3BtreeNext() or sqlite3BtreePrevious()
** operation should be a no-op.
**
** CURSOR_REQUIRESEEK:
** The table that this cursor was opened on still exists, but has been
** modified since the cursor was last used. The cursor position is saved
** in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in
** this state, restoreCursorPosition() can be called to attempt to
** seek the cursor to the saved position.
**
** CURSOR_FAULT:
** An unrecoverable error (an I/O error or a malloc failure) has occurred
** on a different connection that shares the BtShared cache with this
** cursor. The error has left the cache in an inconsistent state.
** Do nothing else with this cursor. Any attempt to use the cursor
** should return the error code stored in BtCursor.skipNext
*/
#define CURSOR_INVALID 0
#define CURSOR_VALID 1
#define CURSOR_SKIPNEXT 2
#define CURSOR_REQUIRESEEK 3
#define CURSOR_FAULT 4
/*
** The database page the PENDING_BYTE occupies. This page is never used.
/* Opaque type used by code in vdbesort.c */
typedef struct VdbeSorter VdbeSorter;
/* Opaque type used by the explainer */
typedef struct Explain Explain;
/* Elements of the linked list at Vdbe.pAuxData */
typedef struct AuxData AuxData;
/*
** A cursor is a pointer into a single BTree within a database file.
** The cursor can seek to a BTree entry with a particular key, or
** loop over all entries of the Btree. You can also insert new BTree
** entries or retrieve the key or data from the entry that the cursor
** is currently pointing to.
**
** Cursors can also point to virtual tables, sorters, or "pseudo-tables".
** A pseudo-table is a single-row table implemented by registers.
**
** Every cursor that the virtual machine has open is represented by an
** instance of the following structure.
*/
struct VdbeCursor {
BtCursor *pCursor; /* The cursor structure of the backend */
Btree *pBt; /* Separate file holding temporary table */
KeyInfo *pKeyInfo; /* Info about index keys needed by index cursors */
int seekResult; /* Result of previous sqlite3BtreeMoveto() */
int pseudoTableReg; /* Register holding pseudotable content. */
i16 nField; /* Number of fields in the header */
u16 nHdrParsed; /* Number of header fields parsed so far */
#ifdef SQLITE_DEBUG
u8 seekOp; /* Most recent seek operation on this cursor */
#endif
i8 iDb; /* Index of cursor database in db->aDb[] (or -1) */
u8 nullRow; /* True if pointing to a row with no data */
u8 deferredMoveto; /* A call to sqlite3BtreeMoveto() is needed */
Bool isEphemeral:1; /* True for an ephemeral table */
Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */
Bool isTable:1; /* True if a table requiring integer keys */
Bool isOrdered:1; /* True if the underlying table is BTREE_UNORDERED */
Pgno pgnoRoot; /* Root page of the open btree cursor */
sqlite3_vtab_cursor *pVtabCursor; /* The cursor for a virtual table */
i64 seqCount; /* Sequence counter */
i64 movetoTarget; /* Argument to the deferred sqlite3BtreeMoveto() */
VdbeSorter *pSorter; /* Sorter object for OP_SorterOpen cursors */
/* Cached information about the header for the data record that the
** cursor is currently pointing to. Only valid if cacheStatus matches
** Vdbe.cacheCtr. Vdbe.cacheCtr will never take on the value of
** CACHE_STALE and so setting cacheStatus=CACHE_STALE guarantees that
** the cache is out of date.
**
** aRow might point to (ephemeral) data for the current row, or it might
** be NULL.
*/
u32 cacheStatus; /* Cache is valid if this matches Vdbe.cacheCtr */
u32 payloadSize; /* Total number of bytes in the record */
u32 szRow; /* Byte available in aRow */
** set to NULL if the currently executing frame is the main program.
*/
typedef struct VdbeFrame VdbeFrame;
struct VdbeFrame {
Vdbe *v; /* VM this frame belongs to */
VdbeFrame *pParent; /* Parent of this frame, or NULL if parent is main */
Op *aOp; /* Program instructions for parent frame */
i64 *anExec; /* Event counters from parent frame */
Mem *aMem; /* Array of memory cells for parent frame */
u8 *aOnceFlag; /* Array of OP_Once flags for parent frame */
VdbeCursor **apCsr; /* Array of Vdbe cursors for parent frame */
void *token; /* Copy of SubProgram.token */
i64 lastRowid; /* Last insert rowid (sqlite3.lastRowid) */
int nCursor; /* Number of entries in apCsr */
int pc; /* Program Counter in parent (calling) frame */
int nOp; /* Size of aOp array */
int nMem; /* Number of entries in aMem */
int nOnceFlag; /* Number of entries in aOnceFlag */
int nChildMem; /* Number of memory cells for child frame */
int nChildCsr; /* Number of cursors for child frame */
int nChange; /* Statement changes (Vdbe.nChange) */
int nDbChange; /* Value of db->nChange */
};
#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])
/*
** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/
#define CACHE_STALE 0
Mem **apArg; /* Arguments to currently executing user function */
Mem *aColName; /* Column names to return */
Mem *pResultSet; /* Pointer to an array of results */
Parse *pParse; /* Parsing context used to create this Vdbe */
int nMem; /* Number of memory locations currently allocated */
int nOp; /* Number of instructions in the program */
int nCursor; /* Number of slots in apCsr[] */
u32 magic; /* Magic number for sanity checking */
char *zErrMsg; /* Error message written here */
Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
VdbeCursor **apCsr; /* One element of this array for each open cursor */
Mem *aVar; /* Values for the OP_Variable opcode. */
char **azVar; /* Name of variables */
ynVar nVar; /* Number of entries in aVar[] */
ynVar nzVar; /* Number of entries in azVar[] */
u32 cacheCtr; /* VdbeCursor row cache generation counter */
int pc; /* The program counter */
int rc; /* Value to return */
u16 nResColumn; /* Number of columns in one row of the result set */
u8 errorAction; /* Recovery action to do in case of an error */
u8 minWriteFileFormat; /* Minimum file format for writable database files */
/* 49 */ "MakeRecord" OpHelp("r[P3]=mkrec(r[P1@P2])"),
/* 50 */ "Count" OpHelp("r[P2]=count()"),
/* 51 */ "ReadCookie" OpHelp(""),
/* 52 */ "SetCookie" OpHelp(""),
/* 53 */ "ReopenIdx" OpHelp("root=P2 iDb=P3"),
/* 54 */ "OpenRead" OpHelp("root=P2 iDb=P3"),
/* 55 */ "OpenWrite" OpHelp("root=P2 iDb=P3"),
/* 56 */ "OpenAutoindex" OpHelp("nColumn=P2"),
/* 57 */ "OpenEphemeral" OpHelp("nColumn=P2"),
/* 58 */ "SorterOpen" OpHelp(""),
/* 59 */ "SequenceTest" OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
/* 60 */ "OpenPseudo" OpHelp("P3 columns in r[P2]"),
/* 61 */ "Close" OpHelp(""),
/* 62 */ "SeekLT" OpHelp("key=r[P3@P4]"),
/* 63 */ "SeekLE" OpHelp("key=r[P3@P4]"),
/* 64 */ "SeekGE" OpHelp("key=r[P3@P4]"),
/* 65 */ "SeekGT" OpHelp("key=r[P3@P4]"),
/* 66 */ "Seek" OpHelp("intkey=r[P2]"),
/* 67 */ "NoConflict" OpHelp("key=r[P3@P4]"),
/* 68 */ "NotFound" OpHelp("key=r[P3@P4]"),
/* 69 */ "Found" OpHelp("key=r[P3@P4]"),
/* 70 */ "NotExists" OpHelp("intkey=r[P3]"),
/* 71 */ "Or" OpHelp("r[P3]=(r[P1] || r[P2])"),
/* 72 */ "And" OpHelp("r[P3]=(r[P1] && r[P2])"),
/* 73 */ "Sequence" OpHelp("r[P2]=cursor[P1].ctr++"),
/* 74 */ "NewRowid" OpHelp("r[P2]=rowid"),
/* 75 */ "Insert" OpHelp("intkey=r[P3] data=r[P2]"),
/* 76 */ "IsNull" OpHelp("if r[P1]==NULL goto P2"),
/* 77 */ "NotNull" OpHelp("if r[P1]!=NULL goto P2"),
/* 78 */ "Ne" OpHelp("if r[P1]!=r[P3] goto P2"),
/* 79 */ "Eq" OpHelp("if r[P1]==r[P3] goto P2"),
/* 80 */ "Gt" OpHelp("if r[P1]>r[P3] goto P2"),
/* 81 */ "Le" OpHelp("if r[P1]<=r[P3] goto P2"),
/* 82 */ "Lt" OpHelp("if r[P1]<r[P3] goto P2"),
/* 83 */ "Ge" OpHelp("if r[P1]>=r[P3] goto P2"),
assert( p->sharable==0 || p->locked==0 || sqlite3_mutex_held(p->pBt->mutex) );
assert( p->sharable==0 || p->locked==0 || sqlite3_mutex_held(p->db->mutex) );
return (p->sharable==0 || p->locked);
}
#endif
#ifndef SQLITE_OMIT_INCRBLOB
/*
** Enter and leave a mutex on a Btree given a cursor owned by that
** Btree. These entry points are used by incremental I/O and can be
** omitted if that module is not used.
*/
SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){
sqlite3BtreeEnter(pCur->pBtree);
}
SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
sqlite3BtreeLeave(pCur->pBtree);
}
#endif /* SQLITE_OMIT_INCRBLOB */
**** This function may be used as part of assert() statements only. ****
**
** Return true if it would be illegal for pBtree to write into the
** table or index rooted at iRoot because other shared connections are
** simultaneously reading that same table or index.
**
** It is illegal for pBtree to write if some other Btree object that
** shares the same BtShared object is currently reading or writing
** the iRoot table. Except, if the other Btree object has the
** read-uncommitted flag set, then it is OK for the other object to
** have a read cursor.
**
** For example, before writing to any part of the table or index
** rooted at page iRoot, one should call:
**
** assert( !hasReadConflicts(pBtree, iRoot) );
*/
static int hasReadConflicts(Btree *pBtree, Pgno iRoot){
BtCursor *p;
for(p=pBtree->pBt->pCursor; p; p=p->pNext){
if( p->pgnoRoot==iRoot
}
}
#endif /* SQLITE_OMIT_SHARED_CACHE */
static void releasePage(MemPage *pPage); /* Forward reference */
/*
***** This routine is used inside of assert() only ****
**
** Verify that the cursor holds the mutex on its BtShared
*/
#ifdef SQLITE_DEBUG
static int cursorHoldsMutex(BtCursor *p){
return sqlite3_mutex_held(p->pBt->mutex);
}
#endif
/*
** Invalidate the overflow cache of the cursor passed as the first argument.
** on the shared btree structure pBt.
*/
#define invalidateOverflowCache(pCur) (pCur->curFlags &= ~BTCF_ValidOvfl)
/*
** Invalidate the overflow page-list cache for all cursors opened
** on the shared btree structure pBt.
*/
static void invalidateAllOverflowCache(BtShared *pBt){
BtCursor *p;
assert( sqlite3_mutex_held(pBt->mutex) );
for(p=pBt->pCursor; p; p=p->pNext){
invalidateOverflowCache(p);
}
}
#ifndef SQLITE_OMIT_INCRBLOB
/*
** This function is called before modifying the contents of a table
** to invalidate any incrblob cursors that are open on the
** row or one of the rows being modified.
**
** If argument isClearTable is true, then the entire contents of the
** table is about to be deleted. In this case invalidate all incrblob
** cursors open on any row within the table with root-page pgnoRoot.
**
** Otherwise, if argument isClearTable is false, then the row with
** rowid iRow is being replaced or deleted. In this case invalidate
** only those incrblob cursors open on that specific row.
*/
static void invalidateIncrblobCursors(
Btree *pBtree, /* The database file to check */
i64 iRow, /* The rowid that might be changing */
int isClearTable /* True if all rows are being deleted */
){
BtCursor *p;
BtShared *pBt = pBtree->pBt;
assert( sqlite3BtreeHoldsMutex(pBtree) );
for(p=pBt->pCursor; p; p=p->pNext){
/*
** Clear (destroy) the BtShared.pHasContent bitvec. This should be
** invoked at the conclusion of each write-transaction.
*/
static void btreeClearHasContent(BtShared *pBt){
sqlite3BitvecDestroy(pBt->pHasContent);
pBt->pHasContent = 0;
}
/*
** Release all of the apPage[] pages for a cursor.
*/
static void btreeReleaseAllCursorPages(BtCursor *pCur){
int i;
for(i=0; i<=pCur->iPage; i++){
releasePage(pCur->apPage[i]);
pCur->apPage[i] = 0;
}
pCur->iPage = -1;
}
/*
** Save the current cursor position in the variables BtCursor.nKey
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
**
** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
** prior to calling this routine.
*/
static int saveCursorPosition(BtCursor *pCur){
int rc;
assert( CURSOR_VALID==pCur->eState );
assert( 0==pCur->pKey );
assert( cursorHoldsMutex(pCur) );
rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
assert( rc==SQLITE_OK ); /* KeySize() cannot fail */
/* If this is an intKey table, then the above call to BtreeKeySize()
** stores the integer key in pCur->nKey. In this case this value is
** all that is required. Otherwise, if pCur is not open on an intKey
** table, then malloc space for and store the pCur->nKey bytes of key
** data.
*/
}
invalidateOverflowCache(pCur);
return rc;
}
/* Forward reference */
static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);
/*
** Save the positions of all cursors (except pExcept) that are open on
** the table with root-page iRoot. "Saving the cursor position" means that
** the location in the btree is remembered in such a way that it can be
** moved back to the same spot after the btree has been modified. This
** routine is called just before cursor pExcept is used to modify the
** table, for example in BtreeDelete() or BtreeInsert().
**
** Implementation note: This routine merely checks to see if any cursors
** need to be saved. It calls out to saveCursorsOnList() in the (unusual)
** event that cursors are in need to being saved.
*/
static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
BtCursor *p;
assert( sqlite3_mutex_held(pBt->mutex) );
assert( pExcept==0 || pExcept->pBt==pBt );
for(p=pBt->pCursor; p; p=p->pNext){
if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ) break;
}
return p ? saveCursorsOnList(p, iRoot, pExcept) : SQLITE_OK;
}
/* This helper routine to saveAllCursors does the actual work of saving
** the cursors if and when a cursor is found that actually requires saving.
** The common case is that no cursors need to be saved, so this routine is
** broken out from its caller to avoid unnecessary stack pointer movement.
*/
static int SQLITE_NOINLINE saveCursorsOnList(
BtCursor *p, /* The first cursor that needs saving */
Pgno iRoot, /* Only save cursor with this iRoot. Save all if zero */
BtCursor *pExcept /* Do not save this cursor */
){
do{
if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){
if( p->eState==CURSOR_VALID ){
int rc = saveCursorPosition(p);
if( SQLITE_OK!=rc ){
return rc;
}
}else{
testcase( p->iPage>0 );
btreeReleaseAllCursorPages(p);
}
}
p = p->pNext;
}while( p );
return SQLITE_OK;
}
/*
** Clear the current cursor position.
*/
SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *pCur){
assert( cursorHoldsMutex(pCur) );
sqlite3_free(pCur->pKey);
pCur->pKey = 0;
pCur->eState = CURSOR_INVALID;
}
/*
** In this version of BtreeMoveto, pKey is a packed index record
** such as is generated by the OP_MakeRecord opcode. Unpack the
** record and then call BtreeMovetoUnpacked() to do the work.
*/
pIdxKey = 0;
}
rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
if( pFree ){
sqlite3DbFree(pCur->pKeyInfo->db, pFree);
}
return rc;
}
/*
** Restore the cursor to the position it was in (or as close to as possible)
** when saveCursorPosition() was called. Note that this call deletes the
** saved position info stored by saveCursorPosition(), so there can be
** at most one effective restoreCursorPosition() call after each
** saveCursorPosition().
*/
static int btreeRestoreCursorPosition(BtCursor *pCur){
int rc;
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState>=CURSOR_REQUIRESEEK );
if( pCur->eState==CURSOR_FAULT ){
return pCur->skipNext;
}
pCur->eState = CURSOR_INVALID;
rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skipNext);
if( rc==SQLITE_OK ){
sqlite3_free(pCur->pKey);
pCur->pKey = 0;
assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
}
return rc;
}
#define restoreCursorPosition(p) \
(p->eState>=CURSOR_REQUIRESEEK ? \
btreeRestoreCursorPosition(p) : \
SQLITE_OK)
/*
** Determine whether or not a cursor has moved from the position where
** it was last placed, or has been invalidated for any other reason.
** Cursors can move when the row they are pointing at is deleted out
** from under them, for example. Cursor might also move if a btree
** is rebalanced.
**
** Calling this routine with a NULL cursor pointer returns false.
**
** Use the separate sqlite3BtreeCursorRestore() routine to restore a cursor
** back to where it ought to be if this routine returns true.
*/
SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor *pCur){
return pCur->eState!=CURSOR_VALID;
}
/*
** This routine restores a cursor back to its original position after it
** has been moved by some outside activity (such as a btree rebalance or
** a row having been deleted out from under the cursor).
**
** On success, the *pDifferentRow parameter is false if the cursor is left
** pointing at exactly the same row. *pDifferntRow is the row the cursor
** was pointing to has been deleted, forcing the cursor to point to some
** nearby row.
**
** This routine should only be called for a cursor that just returned
** TRUE from sqlite3BtreeCursorHasMoved().
*/
SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor *pCur, int *pDifferentRow){
int rc;
assert( pCur!=0 );
assert( pCur->eState!=CURSOR_VALID );
rc = restoreCursorPosition(pCur);
if( rc ){
*pDifferentRow = 1;
*/
static void freeTempSpace(BtShared *pBt){
if( pBt->pTmpSpace ){
pBt->pTmpSpace -= 4;
sqlite3PageFree(pBt->pTmpSpace);
pBt->pTmpSpace = 0;
}
}
/*
** Close an open database and invalidate all cursors.
*/
SQLITE_PRIVATE int sqlite3BtreeClose(Btree *p){
BtShared *pBt = p->pBt;
BtCursor *pCur;
/* Close all cursors opened via this handle. */
assert( sqlite3_mutex_held(p->db->mutex) );
sqlite3BtreeEnter(p);
pCur = pBt->pCursor;
while( pCur ){
BtCursor *pTmp = pCur;
pCur = pCur->pNext;
if( pTmp->pBtree==p ){
sqlite3BtreeCloseCursor(pTmp);
}
}
return SQLITE_OK;
page1_init_failed:
releasePage(pPage1);
pBt->pPage1 = 0;
return rc;
}
#ifndef NDEBUG
/*
** Return the number of cursors open on pBt. This is for use
** in assert() expressions, so it is only compiled if NDEBUG is not
** defined.
**
** Only write cursors are counted if wrOnly is true. If wrOnly is
** false then all cursors are counted.
**
** For the purposes of this routine, a cursor is any cursor that
** is capable of reading or writing to the database. Cursors that
** have been tripped into the CURSOR_FAULT state are not counted.
*/
static int countValidCursors(BtShared *pBt, int wrOnly){
BtCursor *pCur;
int r = 0;
for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
if( (wrOnly==0 || (pCur->curFlags & BTCF_WriteFlag)!=0)
&& pCur->eState!=CURSOR_FAULT ) r++;
}
return r;
}
#endif
/*
** If there are no outstanding cursors and we are not in the middle
** of a transaction but there is a read lock on the database, then
** this routine unrefs the first page of the database file which
** has the effect of releasing the read lock.
**
** If there is a transaction in progress, this routine is a no-op.
*/
static void unlockBtreeIfUnused(BtShared *pBt){
assert( sqlite3_mutex_held(pBt->mutex) );
assert( countValidCursors(pBt,0)==0 || pBt->inTransaction>TRANS_NONE );
if( pBt->inTransaction==TRANS_NONE && pBt->pPage1!=0 ){
** the upper layer will attempt a rollback. However, if the second argument
** is non-zero then this b-tree transaction is part of a multi-file
** transaction. In this case, the transaction has already been committed
** (by deleting a master journal file) and the caller will ignore this
** functions return code. So, even if an error occurs in the pager layer,
** reset the b-tree objects internal state to indicate that the write
** transaction has been closed. This is quite safe, as the pager will have
** transitioned to the error state.
**
** This will release the write lock on the database file. If there
** are no active cursors, it also releases the read lock.
*/
SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree *p, int bCleanup){
if( p->inTrans==TRANS_NONE ) return SQLITE_OK;
sqlite3BtreeEnter(p);
btreeIntegrity(p);
/* If the handle has a write-transaction open, commit the shared-btrees
** transaction and set the shared state to TRANS_READ.
*/
rc = sqlite3BtreeCommitPhaseOne(p, 0);
if( rc==SQLITE_OK ){
rc = sqlite3BtreeCommitPhaseTwo(p, 0);
}
sqlite3BtreeLeave(p);
return rc;
}
/*
** This routine sets the state to CURSOR_FAULT and the error
** code to errCode for every cursor on any BtShared that pBtree
** references. Or if the writeOnly flag is set to 1, then only
** trip write cursors and leave read cursors unchanged.
**
** Every cursor is a candidate to be tripped, including cursors
** that belong to other database connections that happen to be
** sharing the cache with pBtree.
**
** This routine gets called when a rollback occurs. If the writeOnly
** flag is true, then only write-cursors need be tripped - read-only
** cursors save their current positions so that they may continue
** following the rollback. Or, if writeOnly is false, all cursors are
** tripped. In general, writeOnly is false if the transaction being
** rolled back modified the database schema. In this case b-tree root
** pages may be moved or deleted from the database altogether, making
** it unsafe for read cursors to continue.
**
** If the writeOnly flag is true and an error is encountered while
** saving the current position of a read-only cursor, all cursors,
** including all read-cursors are tripped.
**
** SQLITE_OK is returned if successful, or if an error occurs while
** saving a cursor position, an SQLite error code.
*/
SQLITE_PRIVATE int sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode, int writeOnly){
BtCursor *p;
int rc = SQLITE_OK;
assert( (writeOnly==0 || writeOnly==1) && BTCF_WriteFlag==1 );
if( pBtree ){
sqlite3BtreeEnter(pBtree);
for(p=pBtree->pBt->pCursor; p; p=p->pNext){
int i;
}
}
sqlite3BtreeLeave(pBtree);
}
return rc;
}
/*
** Rollback the transaction in progress.
**
** If tripCode is not SQLITE_OK then cursors will be invalidated (tripped).
** Only write cursors are tripped if writeOnly is true but all cursors are
** tripped if writeOnly is false. Any attempt to use
** a tripped cursor will result in an error.
**
** This will release the write lock on the database file. If there
** are no active cursors, it also releases the read lock.
*/
SQLITE_PRIVATE int sqlite3BtreeRollback(Btree *p, int tripCode, int writeOnly){
int rc;
BtShared *pBt = p->pBt;
MemPage *pPage1;
assert( writeOnly==1 || writeOnly==0 );
assert( tripCode==SQLITE_ABORT_ROLLBACK || tripCode==SQLITE_OK );
sqlite3BtreeEnter(p);
if( tripCode==SQLITE_OK ){
** when the transaction started, so we know that the value at offset
** 28 is nonzero. */
assert( pBt->nPage>0 );
}
sqlite3BtreeLeave(p);
}
return rc;
}
/*
** Create a new cursor for the BTree whose root is on the page
** iTable. If a read-only cursor is requested, it is assumed that
** the caller already has at least a read-only transaction open
** on the database already. If a write-cursor is requested, then
** the caller is assumed to have an open write transaction.
**
** If wrFlag==0, then the cursor can only be used for reading.
** If wrFlag==1, then the cursor can be used for reading or for
** writing if other conditions for writing are also met. These
** are the conditions that must be met in order for writing to
** be allowed:
**
** 1: The cursor must have been opened with wrFlag==1
**
** 2: Other database connections that share the same pager cache
** but which are not in the READ_UNCOMMITTED state may not have
** cursors open with wrFlag==0 on the same table. Otherwise
** the changes made by this write cursor would be visible to
** the read cursors in the other database connection.
**
** 3: The database must be writable (not on read-only media)
**
** 4: There must be an active transaction.
**
** No checking is done to make sure that page iTable really is the
** root page of a b-tree. If it is not, then the cursor acquired
** will not work correctly.
**
** It is assumed that the sqlite3BtreeCursorZero() has been called
** on pCur to initialize the memory space prior to invoking this routine.
*/
static int btreeCursor(
Btree *p, /* The btree */
int iTable, /* Root page of table to open */
int wrFlag, /* 1 to write. 0 read-only */
struct KeyInfo *pKeyInfo, /* First arg to comparison function */
BtCursor *pCur /* Space for new cursor */
){
BtShared *pBt = p->pBt; /* Shared b-tree handle */
assert( sqlite3BtreeHoldsMutex(p) );
assert( wrFlag==0 || wrFlag==1 );
/* The following assert statements verify that if this is a sharable
** b-tree database, the connection is holding the required table locks,
** and that no other connection has any open cursor that conflicts with
** this lock. */
assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, wrFlag+1) );
assert( wrFlag==0 || !hasReadConflicts(p, iTable) );
/* Assert that the caller has opened the required transaction. */
assert( p->inTrans>TRANS_NONE );
assert( wrFlag==0 || p->inTrans==TRANS_WRITE );
assert( pBt->pPage1 && pBt->pPage1->aData );
if( NEVER(wrFlag && (pBt->btsFlags & BTS_READ_ONLY)!=0) ){
if( wrFlag ){
allocateTempSpace(pBt);
if( pBt->pTmpSpace==0 ) return SQLITE_NOMEM;
}
if( iTable==1 && btreePagecount(pBt)==0 ){
assert( wrFlag==0 );
iTable = 0;
}
/* Now that no other errors can occur, finish filling in the BtCursor
** variables and link the cursor into the BtShared list. */
pCur->pgnoRoot = (Pgno)iTable;
pCur->iPage = -1;
pCur->pKeyInfo = pKeyInfo;
pCur->pBtree = p;
pCur->pBt = pBt;
assert( wrFlag==0 || wrFlag==BTCF_WriteFlag );
pCur->curFlags = wrFlag;
pCur->pNext = pBt->pCursor;
if( pCur->pNext ){
pCur->pNext->pPrev = pCur;
}
pBt->pCursor = pCur;
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}
SQLITE_PRIVATE int sqlite3BtreeCursor(
Btree *p, /* The btree */
int iTable, /* Root page of table to open */
int wrFlag, /* 1 to write. 0 read-only */
struct KeyInfo *pKeyInfo, /* First arg to xCompare() */
BtCursor *pCur /* Write new cursor here */
){
int rc;
sqlite3BtreeEnter(p);
rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
sqlite3BtreeLeave(p);
return rc;
}
/*
** Return the size of a BtCursor object in bytes.
**
** This interfaces is needed so that users of cursors can preallocate
** sufficient storage to hold a cursor. The BtCursor object is opaque
** to users so they cannot do the sizeof() themselves - they must call
** this routine.
*/
SQLITE_PRIVATE int sqlite3BtreeCursorSize(void){
return ROUND8(sizeof(BtCursor));
}
/*
** Initialize memory that will be converted into a BtCursor object.
**
** The simple approach here would be to memset() the entire object
** to zero. But it turns out that the apPage[] and aiIdx[] arrays
** do not need to be zeroed and they are large, so we can save a lot
** of run-time by skipping the initialization of those elements.
*/
SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor *p){
memset(p, 0, offsetof(BtCursor, iPage));
}
/*
** Close a cursor. The read lock on the database file is released
** when the last cursor is closed.
*/
SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
Btree *pBtree = pCur->pBtree;
if( pBtree ){
int i;
BtShared *pBt = pCur->pBt;
sqlite3BtreeEnter(pBtree);
sqlite3BtreeClearCursor(pCur);
if( pCur->pPrev ){
pCur->pPrev->pNext = pCur->pNext;
int iPage = pCur->iPage; \
btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info); \
pCur->curFlags |= BTCF_ValidNKey; \
}else{ \
assertCellInfo(pCur); \
}
#endif /* _MSC_VER */
#ifndef NDEBUG /* The next routine used only within assert() statements */
/*
** Return true if the given BtCursor is valid. A valid cursor is one
** that is currently pointing to a row in a (non-empty) table.
** This is a verification routine is used only within assert() statements.
*/
SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor *pCur){
return pCur && pCur->eState==CURSOR_VALID;
}
#endif /* NDEBUG */
/*
** Set *pSize to the size of the buffer needed to hold the value of
** the key for the current entry. If the cursor is not pointing
** to a valid entry, *pSize is set to 0.
**
** For a table with the INTKEY flag set, this routine returns the key
** itself, not the number of bytes in the key.
**
** The caller must position the cursor prior to invoking this routine.
**
** This routine cannot fail. It always returns SQLITE_OK.
*/
SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
getCellInfo(pCur);
*pSize = pCur->info.nKey;
return SQLITE_OK;
}
/*
** Set *pSize to the number of bytes of data in the entry the
** cursor currently points to.
**
** The caller must guarantee that the cursor is pointing to a non-NULL
** valid entry. In other words, the calling procedure must guarantee
** that the cursor has Cursor.eState==CURSOR_VALID.
**
** Failure is not possible. This function always returns SQLITE_OK.
** It might just as well be a procedure (returning void) but we continue
** to return an integer result code for historical reasons.
*/
SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
assert( pCur->apPage[pCur->iPage]->intKeyLeaf==1 );
getCellInfo(pCur);
*pSize = pCur->info.nPayload;
return SQLITE_OK;
}
/*
** Given the page number of an overflow page in the database (parameter
** ovfl), this function finds the page number of the next page in the
memcpy(pPayload, pBuf, nByte);
}else{
/* Copy data from page to buffer (a read operation) */
memcpy(pBuf, pPayload, nByte);
}
return SQLITE_OK;
}
/*
** This function is used to read or overwrite payload information
** for the entry that the pCur cursor is pointing to. The eOp
** argument is interpreted as follows:
**
** 0: The operation is a read. Populate the overflow cache.
** 1: The operation is a write. Populate the overflow cache.
** 2: The operation is a read. Do not populate the overflow cache.
**
** A total of "amt" bytes are read or written beginning at "offset".
** Data is read to or from the buffer pBuf.
**
** The content being read or written might appear on the main page
** or be scattered out on multiple overflow pages.
**
** If the current cursor entry uses one or more overflow pages and the
** eOp argument is not 2, this function may allocate space for and lazily
** populates the overflow page-list cache array (BtCursor.aOverflow).
** Subsequent calls use this cache to make seeking to the supplied offset
** more efficient.
**
** Once an overflow page-list cache has been allocated, it may be
** invalidated if some other cursor writes to the same table, or if
** the cursor is moved to a different row. Additionally, in auto-vacuum
** mode, the following events may invalidate an overflow page-list cache.
**
** * An incremental vacuum,
** * A commit in auto_vacuum="full" mode,
** * Creating a table (may require moving an overflow page).
*/
static int accessPayload(
BtCursor *pCur, /* Cursor pointing to entry to read from */
u32 offset, /* Begin reading this far into payload */
u32 amt, /* Read this many bytes */
unsigned char *pBuf, /* Write the bytes into this buffer */
int eOp /* zero to read. non-zero to write. */
){
unsigned char *aPayload;
int rc = SQLITE_OK;
int iIdx = 0;
MemPage *pPage = pCur->apPage[pCur->iPage]; /* Btree page of current entry */
BtShared *pBt = pCur->pBt; /* Btree this cursor belongs to */
#ifdef SQLITE_DIRECT_OVERFLOW_READ
unsigned char * const pBufStart = pBuf;
int bEnd; /* True if reading to end of data */
#endif
assert( pPage );
assert( pCur->eState==CURSOR_VALID );
assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
assert( cursorHoldsMutex(pCur) );
assert( eOp!=2 || offset==0 ); /* Always start from beginning for eOp==2 */
getCellInfo(pCur);
aPayload = pCur->info.pPayload;
#ifdef SQLITE_DIRECT_OVERFLOW_READ
bEnd = offset+amt==pCur->info.nPayload;
#endif
assert( offset+amt <= pCur->info.nPayload );
if( &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize] ){
}
}
if( rc==SQLITE_OK && amt>0 ){
return SQLITE_CORRUPT_BKPT;
}
return rc;
}
/*
** Read part of the key associated with cursor pCur. Exactly
** "amt" bytes will be transferred into pBuf[]. The transfer
** begins at "offset".
**
** The caller must ensure that pCur is pointing to a valid row
** in the table.
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong. An error is returned if "offset+amt" is larger than
** the available payload.
*/
SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
return accessPayload(pCur, offset, amt, (unsigned char*)pBuf, 0);
}
/*
** Read part of the data associated with cursor pCur. Exactly
** "amt" bytes will be transfered into pBuf[]. The transfer
** begins at "offset".
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong. An error is returned if "offset+amt" is larger than
** the available payload.
*/
SQLITE_PRIVATE int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
int rc;
#ifndef SQLITE_OMIT_INCRBLOB
if ( pCur->eState==CURSOR_INVALID ){
return SQLITE_ABORT;
}
#endif
assert( cursorHoldsMutex(pCur) );
rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_VALID );
assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
rc = accessPayload(pCur, offset, amt, pBuf, 0);
}
return rc;
}
/*
** Return a pointer to payload information from the entry that the
** pCur cursor is pointing to. The pointer is to the beginning of
** the key if index btrees (pPage->intKey==0) and is the data for
** table btrees (pPage->intKey==1). The number of bytes of available
** key/data is written into *pAmt. If *pAmt==0, then the value
** returned will not be a valid pointer.
**
** This routine is an optimization. It is common for the entire key
** and data to fit on the local page and for there to be no overflow
** pages. When that is so, this routine can be used to access the
** key and data without making a copy. If the key and/or data spills
** onto overflow pages, then accessPayload() must be used to reassemble
** page of the database. The data might change or move the next time
** any btree routine is called.
*/
static const void *fetchPayload(
BtCursor *pCur, /* Cursor pointing to entry to read from */
u32 *pAmt /* Write the number of available bytes here */
){
assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
assert( pCur->eState==CURSOR_VALID );
assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
assert( cursorHoldsMutex(pCur) );
assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
assert( pCur->info.nSize>0 );
*pAmt = pCur->info.nLocal;
return (void*)pCur->info.pPayload;
}
/*
** For the entry that cursor pCur is point to, return as
** many bytes of the key or data as are available on the local
** b-tree page. Write the number of available bytes into *pAmt.
**
** The pointer returned is ephemeral. The key/data may move
** or be destroyed on the next call to any Btree routine,
** including calls from other threads against the same cache.
** Hence, a mutex on the BtShared should be held prior to calling
** this routine.
**
** These routines is used to get quick access to key and data
*/
SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor *pCur, u32 *pAmt){
return fetchPayload(pCur, pAmt);
}
SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor *pCur, u32 *pAmt){
return fetchPayload(pCur, pAmt);
}
/*
** Move the cursor down to a new child page. The newPgno argument is the
** page number of the child page to move to.
**
** This function returns SQLITE_CORRUPT if the page-header flags field of
** the new child page does not match the flags field of the parent (i.e.
** if an intkey page appears to be the parent of a non-intkey page, or
** vice-versa).
*/
static int moveToChild(BtCursor *pCur, u32 newPgno){
int rc;
int i = pCur->iPage;
MemPage *pNewPage;
BtShared *pBt = pCur->pBt;
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
assert( pCur->iPage>=0 );
if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
return SQLITE_CORRUPT_BKPT;
}
rc = getAndInitPage(pBt, newPgno, &pNewPage,
(pCur->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
if( rc ) return rc;
pCur->apPage[i+1] = pNewPage;
assert( get4byte(&pParent->aData[pParent->hdrOffset+8])==iChild );
}else{
assert( get4byte(findCell(pParent, iIdx))==iChild );
}
}
#else
# define assertParentIndex(x,y,z)
#endif
/*
** Move the cursor up to the parent page.
**
** pCur->idx is set to the cell index that contains the pointer
** to the page we are coming from. If we are coming from the
** right-most child page then pCur->idx is set to one more than
** the largest cell index.
*/
static void moveToParent(BtCursor *pCur){
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
assert( pCur->iPage>0 );
assert( pCur->apPage[pCur->iPage] );
/* UPDATE: It is actually possible for the condition tested by the assert
** below to be untrue if the database file is corrupt. This can occur if
** one cursor has modified page pParent while a reference to it is held
** by a second cursor. Which can only happen if a single page is linked
** into more than one b-tree structure in a corrupt database. */
#if 0
assertParentIndex(
pCur->apPage[pCur->iPage-1],
pCur->aiIdx[pCur->iPage-1],
pCur->apPage[pCur->iPage]->pgno
);
#endif
testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );
releasePage(pCur->apPage[pCur->iPage]);
pCur->iPage--;
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
}
/*
** Move the cursor to point to the root page of its b-tree structure.
**
** If the table has a virtual root page, then the cursor is moved to point
** to the virtual root page instead of the actual root page. A table has a
** virtual root page when the actual root page contains no cells and a
** single child page. This can only happen with the table rooted at page 1.
**
** If the b-tree structure is empty, the cursor state is set to
** CURSOR_INVALID. Otherwise, the cursor is set to point to the first
** cell located on the root (or virtual root) page and the cursor state
** is set to CURSOR_VALID.
**
** If this function returns successfully, it may be assumed that the
** page-header flags indicate that the [virtual] root-page is the expected
** kind of b-tree page (i.e. if when opening the cursor the caller did not
** specify a KeyInfo structure the flags byte is set to 0x05 or 0x0D,
** indicating a table b-tree, or if the caller did specify a KeyInfo
** structure the flags byte is set to 0x02 or 0x0A, indicating an index
** b-tree).
*/
static int moveToRoot(BtCursor *pCur){
MemPage *pRoot;
int rc = SQLITE_OK;
assert( cursorHoldsMutex(pCur) );
assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
assert( CURSOR_VALID < CURSOR_REQUIRESEEK );
assert( CURSOR_FAULT > CURSOR_REQUIRESEEK );
if( pCur->eState>=CURSOR_REQUIRESEEK ){
if( pCur->eState==CURSOR_FAULT ){
assert( pCur->skipNext!=SQLITE_OK );
return pCur->skipNext;
}
sqlite3BtreeClearCursor(pCur);
}
(pCur->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
if( rc!=SQLITE_OK ){
pCur->eState = CURSOR_INVALID;
return rc;
}
pCur->iPage = 0;
}
pRoot = pCur->apPage[0];
assert( pRoot->pgno==pCur->pgnoRoot );
/* If pCur->pKeyInfo is not NULL, then the caller that opened this cursor
** expected to open it on an index b-tree. Otherwise, if pKeyInfo is
** NULL, the caller expects a table b-tree. If this is not the case,
** return an SQLITE_CORRUPT error.
**
** Earlier versions of SQLite assumed that this test could not fail
** if the root page was already loaded when this function was called (i.e.
** if pCur->iPage>=0). But this is not so if the database is corrupted
** in such a way that page pRoot is linked into a second b-tree table
** (or the freelist). */
assert( pRoot->intKey==1 || pRoot->intKey==0 );
subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
pCur->eState = CURSOR_VALID;
rc = moveToChild(pCur, subpage);
}else{
pCur->eState = CURSOR_INVALID;
}
return rc;
}
/*
** Move the cursor down to the left-most leaf entry beneath the
** entry to which it is currently pointing.
**
** The left-most leaf is the one with the smallest key - the first
** in ascending order.
*/
static int moveToLeftmost(BtCursor *pCur){
Pgno pgno;
int rc = SQLITE_OK;
MemPage *pPage;
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
while( rc==SQLITE_OK && !(pPage = pCur->apPage[pCur->iPage])->leaf ){
assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
pgno = get4byte(findCell(pPage, pCur->aiIdx[pCur->iPage]));
rc = moveToChild(pCur, pgno);
}
return rc;
}
/*
** Move the cursor down to the right-most leaf entry beneath the
** page to which it is currently pointing. Notice the difference
** between moveToLeftmost() and moveToRightmost(). moveToLeftmost()
** finds the left-most entry beneath the *entry* whereas moveToRightmost()
** finds the right-most entry beneath the *page*.
**
** The right-most entry is the one with the largest key - the last
** key in ascending order.
*/
static int moveToRightmost(BtCursor *pCur){
Pgno pgno;
int rc = SQLITE_OK;
MemPage *pPage = 0;
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
while( !(pPage = pCur->apPage[pCur->iPage])->leaf ){
pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
pCur->aiIdx[pCur->iPage] = pPage->nCell;
rc = moveToChild(pCur, pgno);
if( rc ) return rc;
}
pCur->aiIdx[pCur->iPage] = pPage->nCell-1;
assert( pCur->info.nSize==0 );
assert( (pCur->curFlags & BTCF_ValidNKey)==0 );
return SQLITE_OK;
}
/* Move the cursor to the first entry in the table. Return SQLITE_OK
** on success. Set *pRes to 0 if the cursor actually points to something
** or set *pRes to 1 if the table is empty.
*/
SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
int rc;
assert( cursorHoldsMutex(pCur) );
assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
rc = moveToRoot(pCur);
if( rc==SQLITE_OK ){
if( pCur->eState==CURSOR_INVALID ){
assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
*pRes = 1;
}else{
assert( pCur->apPage[pCur->iPage]->nCell>0 );
*pRes = 0;
rc = moveToLeftmost(pCur);
}
}
return rc;
}
/* Move the cursor to the last entry in the table. Return SQLITE_OK
** on success. Set *pRes to 0 if the cursor actually points to something
** or set *pRes to 1 if the table is empty.
*/
SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
int rc;
assert( cursorHoldsMutex(pCur) );
assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
/* If the cursor already points to the last entry, this is a no-op. */
if( CURSOR_VALID==pCur->eState && (pCur->curFlags & BTCF_AtLast)!=0 ){
#ifdef SQLITE_DEBUG
/* This block serves to assert() that the cursor really does point
** to the last entry in the b-tree. */
int ii;
for(ii=0; ii<pCur->iPage; ii++){
assert( pCur->aiIdx[ii]==pCur->apPage[ii]->nCell );
}
assert( pCur->aiIdx[pCur->iPage]==pCur->apPage[pCur->iPage]->nCell-1 );
assert( pCur->apPage[pCur->iPage]->leaf );
#endif
return SQLITE_OK;
}
pCur->curFlags |= BTCF_AtLast;
}else{
pCur->curFlags &= ~BTCF_AtLast;
}
}
}
return rc;
}
/* Move the cursor so that it points to an entry near the key
** specified by pIdxKey or intKey. Return a success code.
**
** For INTKEY tables, the intKey parameter is used. pIdxKey
** must be NULL. For index tables, pIdxKey is used and intKey
** is ignored.
**
** If an exact match is not found, then the cursor is always
** left pointing at a leaf page which would hold the entry if it
** were present. The cursor might point to an entry that comes
** before or after the key.
**
** An integer is written into *pRes which is the result of
** comparing the key with the entry to which the cursor is
** pointing. The meaning of the integer written into
** *pRes is as follows:
**
** *pRes<0 The cursor is left pointing at an entry that
** is smaller than intKey/pIdxKey or if the table is empty
** and the cursor is therefore left point to nothing.
**
** *pRes==0 The cursor is left pointing at an entry that
** exactly matches intKey/pIdxKey.
**
** *pRes>0 The cursor is left pointing at an entry that
** is larger than intKey/pIdxKey.
**
*/
SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
BtCursor *pCur, /* The cursor to be moved */
UnpackedRecord *pIdxKey, /* Unpacked index key */
i64 intKey, /* The table key */
int biasRight, /* If true, bias the search to the high end */
int *pRes /* Write search results here */
){
int rc;
RecordCompare xRecordCompare;
assert( cursorHoldsMutex(pCur) );
assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
assert( pRes );
assert( (pIdxKey==0)==(pCur->pKeyInfo==0) );
/* If the cursor is already positioned at the point we are trying
** to move to, then just return without doing any work */
if( pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0
&& pCur->apPage[0]->intKey
){
if( pCur->info.nKey==intKey ){
*pRes = 0;
return SQLITE_OK;
}
if( (pCur->curFlags & BTCF_AtLast)!=0 && pCur->info.nKey<intKey ){
*pRes = -1;
return SQLITE_OK;
}
assert( pCur->apPage[0]->intKey || pIdxKey );
for(;;){
int lwr, upr, idx, c;
Pgno chldPg;
MemPage *pPage = pCur->apPage[pCur->iPage];
u8 *pCell; /* Pointer to current cell in pPage */
/* pPage->nCell must be greater than zero. If this is the root-page
** the cursor would have been INVALID above and this for(;;) loop
** not run. If this is not the root-page, then the moveToChild() routine
** would have already detected db corruption. Similarly, pPage must
** be the right kind (index or table) of b-tree page. Otherwise
** a moveToChild() or moveToRoot() call would have detected corruption. */
assert( pPage->nCell>0 );
assert( pPage->intKey==(pIdxKey==0) );
lwr = 0;
upr = pPage->nCell-1;
assert( biasRight==0 || biasRight==1 );
idx = upr>>(1-biasRight); /* idx = biasRight ? upr : (lwr+upr)/2; */
if( rc ) break;
}
moveto_finish:
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
return rc;
}
/*
** Return TRUE if the cursor is not pointing at an entry of the table.
**
** TRUE will be returned after a call to sqlite3BtreeNext() moves
** past the last entry in the table or sqlite3BtreePrev() moves past
** the first entry. TRUE is also returned if the table is empty.
*/
SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor *pCur){
/* TODO: What if the cursor is in CURSOR_REQUIRESEEK but all table entries
** have been deleted? This API will need to change to return an error code
** as well as the boolean result value.
*/
return (CURSOR_VALID!=pCur->eState);
}
/*
** Advance the cursor to the next entry in the database. If
** successful then set *pRes=0. If the cursor
** was already pointing to the last entry in the database before
** this routine was called, then set *pRes=1.
**
** The main entry point is sqlite3BtreeNext(). That routine is optimized
** for the common case of merely incrementing the cell counter BtCursor.aiIdx
** to the next cell on the current page. The (slower) btreeNext() helper
** routine is called when it is necessary to move to a different page or
** to restore the cursor.
**
** The calling function will set *pRes to 0 or 1. The initial *pRes value
** will be 1 if the cursor being stepped corresponds to an SQL index and
** if this routine could have been skipped if that SQL index had been
** a unique index. Otherwise the caller will have set *pRes to zero.
** Zero is the common case. The btree implementation is free to use the
** initial *pRes value as a hint to improve performance, but the current
** SQLite btree implementation does not. (Note that the comdb2 btree
** implementation does use this hint, however.)
*/
static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
int rc;
int idx;
MemPage *pPage;
assert( cursorHoldsMutex(pCur) );
assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
assert( *pRes==0 );
if( pCur->eState!=CURSOR_VALID ){
assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );
rc = restoreCursorPosition(pCur);
if( rc!=SQLITE_OK ){
return rc;
}
if( CURSOR_INVALID==pCur->eState ){
*pRes = 1;
}
pCur->skipNext = 0;
}
}
pPage = pCur->apPage[pCur->iPage];
idx = ++pCur->aiIdx[pCur->iPage];
assert( pPage->isInit );
/* If the database file is corrupt, it is possible for the value of idx
** to be invalid here. This can only occur if a second cursor modifies
** the page while cursor pCur is holding a reference to it. Which can
** only happen if the database is corrupt in such a way as to link the
** page into more than one b-tree structure. */
testcase( idx>pPage->nCell );
if( idx>=pPage->nCell ){
if( !pPage->leaf ){
rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
if( rc ) return rc;
return moveToLeftmost(pCur);
}
}
}
if( pPage->leaf ){
return SQLITE_OK;
}else{
return moveToLeftmost(pCur);
}
}
SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
MemPage *pPage;
assert( cursorHoldsMutex(pCur) );
assert( pRes!=0 );
assert( *pRes==0 || *pRes==1 );
assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
*pRes = 0;
if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur, pRes);
pPage = pCur->apPage[pCur->iPage];
if( (++pCur->aiIdx[pCur->iPage])>=pPage->nCell ){
pCur->aiIdx[pCur->iPage]--;
return btreeNext(pCur, pRes);
}
if( pPage->leaf ){
return SQLITE_OK;
}else{
return moveToLeftmost(pCur);
}
}
/*
** Step the cursor to the back to the previous entry in the database. If
** successful then set *pRes=0. If the cursor
** was already pointing to the first entry in the database before
** this routine was called, then set *pRes=1.
**
** The main entry point is sqlite3BtreePrevious(). That routine is optimized
** for the common case of merely decrementing the cell counter BtCursor.aiIdx
** to the previous cell on the current page. The (slower) btreePrevious()
** helper routine is called when it is necessary to move to a different page
** or to restore the cursor.
**
** The calling function will set *pRes to 0 or 1. The initial *pRes value
** will be 1 if the cursor being stepped corresponds to an SQL index and
** if this routine could have been skipped if that SQL index had been
** a unique index. Otherwise the caller will have set *pRes to zero.
** Zero is the common case. The btree implementation is free to use the
** initial *pRes value as a hint to improve performance, but the current
** SQLite btree implementation does not. (Note that the comdb2 btree
** implementation does use this hint, however.)
*/
static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur, int *pRes){
int rc;
MemPage *pPage;
assert( cursorHoldsMutex(pCur) );
assert( pRes!=0 );
assert( *pRes==0 );
assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
assert( (pCur->curFlags & (BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey))==0 );
assert( pCur->info.nSize==0 );
if( pCur->eState!=CURSOR_VALID ){
rc = restoreCursorPosition(pCur);
if( rc!=SQLITE_OK ){
return rc;
}
pPage = pCur->apPage[pCur->iPage];
if( pPage->intKey && !pPage->leaf ){
rc = sqlite3BtreePrevious(pCur, pRes);
}else{
rc = SQLITE_OK;
}
}
return rc;
}
SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
assert( cursorHoldsMutex(pCur) );
assert( pRes!=0 );
assert( *pRes==0 || *pRes==1 );
assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
*pRes = 0;
pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey);
pCur->info.nSize = 0;
if( pCur->eState!=CURSOR_VALID
|| pCur->aiIdx[pCur->iPage]==0
|| pCur->apPage[pCur->iPage]->leaf==0
){
return SQLITE_CORRUPT_BKPT;
}
if( nOvfl ){
rc = getOverflowPage(pBt, ovflPgno, &pOvfl, &iNext);
if( rc ) return rc;
}
if( ( pOvfl || ((pOvfl = btreePageLookup(pBt, ovflPgno))!=0) )
&& sqlite3PagerPageRefcount(pOvfl->pDbPage)!=1
){
/* There is no reason any cursor should have an outstanding reference
** to an overflow page belonging to a cell that is being deleted/updated.
** So if there exists more than one reference to this page, then it
** must not really be an overflow page and the database must be corrupt.
** It is helpful to detect this before calling freePage2(), as
** freePage2() may zero the page contents if secure-delete mode is
** enabled. If this 'overflow' page happens to be a page that the
** caller is iterating through or using in some other way, this
** can be problematic.
*/
rc = SQLITE_CORRUPT_BKPT;
if( pFree ){
sqlite3PageFree(pFree);
}
return rc;
}
/*
** Insert a new record into the BTree. The key is given by (pKey,nKey)
** and the data is given by (pData,nData). The cursor is used only to
** define what table the record should be inserted into. The cursor
** is left pointing at a random location.
**
** For an INTKEY table, only the nKey value of the key is used. pKey is
** ignored. For a ZERODATA table, the pData and nData are both ignored.
**
** If the seekResult parameter is non-zero, then a successful call to
** MovetoUnpacked() to seek cursor pCur to (pKey, nKey) has already
** been performed. seekResult is the search result returned (a negative
** number if pCur points at an entry that is smaller than (pKey, nKey), or
** a positive value if pCur points at an entry that is larger than
** (pKey, nKey)).
**
** If the seekResult parameter is non-zero, then the caller guarantees that
** cursor pCur is pointing at the existing copy of a row that is to be
** overwritten. If the seekResult parameter is 0, then cursor pCur may
** point to any entry or to no entry at all and so this function has to seek
** the cursor before the new key can be inserted.
*/
SQLITE_PRIVATE int sqlite3BtreeInsert(
BtCursor *pCur, /* Insert data into the table of this cursor */
const void *pKey, i64 nKey, /* The key of the new record */
const void *pData, int nData, /* The data of the new record */
int nZero, /* Number of extra 0 bytes to append to data */
int appendBias, /* True if this is likely an append */
int seekResult /* Result of prior MovetoUnpacked() call */
){
int rc;
int loc = seekResult; /* -1: before desired location +1: after */
int szNew = 0;
int idx;
Btree *p = pCur->pBtree;
BtShared *pBt = p->pBt;
unsigned char *oldCell;
unsigned char *newCell = 0;
if( pCur->eState==CURSOR_FAULT ){
assert( pCur->skipNext!=SQLITE_OK );
return pCur->skipNext;
}
assert( cursorHoldsMutex(pCur) );
assert( (pCur->curFlags & BTCF_WriteFlag)!=0
&& pBt->inTransaction==TRANS_WRITE
&& (pBt->btsFlags & BTS_READ_ONLY)==0 );
assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
/* Assert that the caller has been consistent. If this cursor was opened
** expecting an index b-tree, then the caller should be inserting blob
** keys with no associated data. If the cursor was opened expecting an
** intkey table, the caller should be inserting integer keys with a
** blob of associated data. */
assert( (pKey==0)==(pCur->pKeyInfo==0) );
/* Save the positions of any other cursors open on this table.
**
** In some cases, the call to btreeMoveto() below is a no-op. For
** example, when inserting data into a table with auto-generated integer
** keys, the VDBE layer invokes sqlite3BtreeLast() to figure out the
** integer key to use. It then calls this function to actually insert the
** data into the intkey B-Tree. In this case btreeMoveto() recognizes
** that the cursor is already where it needs to be and returns without
** doing any work. To avoid thwarting these optimizations, it is important
** not to clear the cursor here.
*/
rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
if( rc ) return rc;
if( pCur->pKeyInfo==0 ){
/* If this is an insert into a table b-tree, invalidate any incrblob
** cursors open on the row being replaced */
invalidateIncrblobCursors(p, nKey, 0);
/* If the cursor is currently on the last row and we are appending a
** new row onto the end, set the "loc" to avoid an unnecessary btreeMoveto()
** call */
if( (pCur->curFlags&BTCF_ValidNKey)!=0 && nKey>0
&& pCur->info.nKey==nKey-1 ){
loc = -1;
}
}
if( !loc ){
rc = btreeMoveto(pCur, pKey, nKey, appendBias, &loc);
assert( pPage->leaf );
idx = ++pCur->aiIdx[pCur->iPage];
}else{
assert( pPage->leaf );
}
insertCell(pPage, idx, newCell, szNew, 0, 0, &rc);
assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );
/* If no error has occurred and pPage has an overflow cell, call balance()
** to redistribute the cells within the tree. Since balance() may move
** the cursor, zero the BtCursor.info.nSize and BTCF_ValidNKey
** variables.
**
** Previous versions of SQLite called moveToRoot() to move the cursor
** back to the root page as balance() used to invalidate the contents
** of BtCursor.apPage[] and BtCursor.aiIdx[]. Instead of doing that,
** set the cursor state to "invalid". This makes common insert operations
** slightly faster.
**
** There is a subtle but important optimization here too. When inserting
** multiple records into an intkey b-tree using a single cursor (as can
** happen while processing an "INSERT INTO ... SELECT" statement), it
** is advantageous to leave the cursor pointing to the last entry in
** the b-tree if possible. If the cursor is left pointing to the last
** entry in the table, and the next row inserted has an integer key
** larger than the largest existing key, it is possible to insert the
** row without seeking the cursor. This can be a big performance boost.
*/
pCur->info.nSize = 0;
if( rc==SQLITE_OK && pPage->nOverflow ){
pCur->curFlags &= ~(BTCF_ValidNKey);
rc = balance(pCur);
/* Must make sure nOverflow is reset to zero even if the balance()
** fails. Internal data structure corruption will result otherwise.
** Also, set the cursor state to invalid. This stops saveCursorPosition()
** from trying to save the current position of the cursor. */
pCur->apPage[pCur->iPage]->nOverflow = 0;
pCur->eState = CURSOR_INVALID;
}
assert( pCur->apPage[pCur->iPage]->nOverflow==0 );
end_insert:
return rc;
}
/*
** Delete the entry that the cursor is pointing to. The cursor
** is left pointing at an arbitrary location.
*/
SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
Btree *p = pCur->pBtree;
BtShared *pBt = p->pBt;
int rc; /* Return code */
MemPage *pPage; /* Page to delete cell from */
unsigned char *pCell; /* Pointer to cell to delete */
int iCellIdx; /* Index of cell to delete */
int iCellDepth; /* Depth of node containing pCell */
u16 szCell; /* Size of the cell being deleted */
assert( cursorHoldsMutex(pCur) );
assert( pBt->inTransaction==TRANS_WRITE );
assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
assert( pCur->curFlags & BTCF_WriteFlag );
assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
assert( !hasReadConflicts(p, pCur->pgnoRoot) );
if( NEVER(pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell)
|| NEVER(pCur->eState!=CURSOR_VALID)
){
return SQLITE_ERROR; /* Something has gone awry. */
}
iCellDepth = pCur->iPage;
iCellIdx = pCur->aiIdx[iCellDepth];
pPage = pCur->apPage[iCellDepth];
pCell = findCell(pPage, iCellIdx);
/* If the page containing the entry to delete is not a leaf page, move
** the cursor to the largest entry in the tree that is smaller than
** the entry being deleted. This cell will replace the cell being deleted
** from the internal node. The 'previous' entry is used for this instead
** of the 'next' entry, as the previous entry is always a part of the
** sub-tree headed by the child page of the cell being deleted. This makes
** balancing the tree following the delete operation easier. */
if( !pPage->leaf ){
int notUsed = 0;
rc = sqlite3BtreePrevious(pCur, ¬Used);
if( rc ) return rc;
}
/* Save the positions of any other cursors open on this table before
** making any modifications. Make the page containing the entry to be
** deleted writable. Then free any overflow pages associated with the
** entry and finally remove the cell itself from within the page.
*/
rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
if( rc ) return rc;
/* If this is a delete operation to remove a row from a table b-tree,
** invalidate any incrblob cursors open on the row being deleted. */
if( pCur->pKeyInfo==0 ){
invalidateIncrblobCursors(p, pCur->info.nKey, 0);
}
rc = sqlite3PagerWrite(pPage->pDbPage);
if( rc ) return rc;
rc = clearCell(pPage, pCell, &szCell);
dropCell(pPage, iCellIdx, szCell, &rc);
if( rc ) return rc;
/* If the cell deleted was not located on a leaf page, then the cursor
** is currently pointing to the largest entry in the sub-tree headed
** by the child-page of the cell that was just deleted from an internal
** node. The cell from the leaf node needs to be moved to the internal
** node to replace the deleted cell. */
if( !pPage->leaf ){
MemPage *pLeaf = pCur->apPage[pCur->iPage];
int nCell;
Pgno n = pCur->apPage[iCellDepth+1]->pgno;
unsigned char *pTmp;
assert( MX_CELL_SIZE(pBt) >= nCell );
pTmp = pBt->pTmpSpace;
assert( pTmp!=0 );
rc = sqlite3PagerWrite(pLeaf->pDbPage);
insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);
dropCell(pLeaf, pLeaf->nCell-1, nCell, &rc);
if( rc ) return rc;
}
/* Balance the tree. If the entry deleted was located on a leaf page,
** then the cursor still points to that page. In this case the first
** call to balance() repairs the tree, and the if(...) condition is
** never true.
**
** Otherwise, if the entry deleted was on an internal node page, then
** pCur is pointing to the leaf page from which a cell was removed to
** replace the cell deleted from the internal node. This is slightly
** tricky as the leaf node may be underfull, and the internal node may
** be either under or overfull. In this case run the balancing algorithm
** on the leaf node first. If the balance proceeds far enough up the
** tree that we can be sure that any problem in the internal node has
** been corrected, so be it. Otherwise, after balancing the leaf node,
** walk the cursor up the tree to the internal node and balance it as
** well. */
rc = balance(pCur);
if( rc==SQLITE_OK && pCur->iPage>iCellDepth ){
while( pCur->iPage>iCellDepth ){
releasePage(pCur->apPage[pCur->iPage--]);
}
rc = balance(pCur);
}
if( rc==SQLITE_OK ){
return rc;
}
#else
if( pBt->autoVacuum ){
Pgno pgnoMove; /* Move a page here to make room for the root-page */
MemPage *pPageMove; /* The page to move to. */
/* Creating a new table may probably require moving an existing database
** to make room for the new tables root page. In case this page turns
** out to be an overflow page, delete all overflow page-map caches
** held by open cursors.
*/
invalidateAllOverflowCache(pBt);
/* Read the value of meta[3] from the database to determine where the
** root page of the new table should go. meta[3] is the largest root-page
** created so far, so the new root-page is (meta[3]+1).
*/
sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &pgnoRoot);
pgnoRoot++;
if( pgnoMove!=pgnoRoot ){
/* pgnoRoot is the page that will be used for the root-page of
** the new table (assuming an error did not occur). But we were
** allocated pgnoMove. If required (i.e. if it was not allocated
** by extending the file), the current page at position pgnoMove
** is already journaled.
*/
u8 eType = 0;
Pgno iPtrPage = 0;
/* Save the positions of any open cursors. This is required in
** case they are holding a reference to an xFetch reference
** corresponding to page pgnoRoot. */
rc = saveAllCursors(pBt, 0, 0);
releasePage(pPageMove);
if( rc!=SQLITE_OK ){
return rc;
}
/* Move the page currently at pgnoRoot to pgnoMove. */
rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
releasePage(pPage);
return rc;
}
/*
** Delete all information from a single table in the database. iTable is
** the page number of the root of the table. After this routine returns,
** the root page is empty, but still exists.
**
** This routine will fail with SQLITE_LOCKED if there are any open
** read cursors on the table. Open write cursors are moved to the
** root of the table.
**
** If pnChange is not NULL, then table iTable must be an intkey table. The
** integer value pointed to by pnChange is incremented by the number of
** entries in the table.
*/
SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree *p, int iTable, int *pnChange){
int rc;
BtShared *pBt = p->pBt;
sqlite3BtreeEnter(p);
assert( p->inTrans==TRANS_WRITE );
rc = saveAllCursors(pBt, (Pgno)iTable, 0);
if( SQLITE_OK==rc ){
/* Invalidate all incrblob cursors open on table iTable (assuming iTable
** is the root of a table b-tree - if it is not, the following call is
** a no-op). */
invalidateIncrblobCursors(p, 0, 1);
rc = clearDatabasePage(pBt, (Pgno)iTable, 0, pnChange);
}
sqlite3BtreeLeave(p);
return rc;
}
/*
SQLITE_PRIVATE int sqlite3BtreeClearTableOfCursor(BtCursor *pCur){
return sqlite3BtreeClearTable(pCur->pBtree, pCur->pgnoRoot, 0);
}
/*
** Erase all information in a table and add the root of the table to
** the freelist. Except, the root of the principle table (the one on
** page 1) is never added to the freelist.
**
** This routine will fail with SQLITE_LOCKED if there are any open
** cursors on the table.
**
** If AUTOVACUUM is enabled and the page at iTable is not the last
** root page in the database file, then the last root page
** in the database file is moved into the slot formerly occupied by
** iTable and that last slot formerly occupied by the last root page
** is added to the freelist instead of iTable. In this say, all
** root pages are kept at the beginning of the database file, which
** is necessary for AUTOVACUUM to work right. *piMoved is set to the
** page number that used to be the last root page in the file before
** the move. If no page gets moved, *piMoved is set to 0.
** meta[3] is updated by this procedure.
*/
static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
int rc;
MemPage *pPage = 0;
BtShared *pBt = p->pBt;
assert( sqlite3BtreeHoldsMutex(p) );
assert( p->inTrans==TRANS_WRITE );
/* It is illegal to drop a table if any cursors are open on the
** database. This is because in auto-vacuum mode the backend may
** need to move another root-page to fill a gap left by the deleted
** root page. If an open cursor was using this page a problem would
** occur.
**
** This error is caught long before control reaches this point.
*/
if( NEVER(pBt->pCursor) ){
sqlite3ConnectionBlocked(p->db, pBt->pCursor->pBtree->db);
return SQLITE_LOCKED_SHAREDCACHE;
}
rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
pBt->incrVacuum = (u8)iMeta;
}
#endif
}
sqlite3BtreeLeave(p);
return rc;
}
#ifndef SQLITE_OMIT_BTREECOUNT
/*
** The first argument, pCur, is a cursor opened on some b-tree. Count the
** number of entries in the b-tree and write the result to *pnEntry.
**
** SQLITE_OK is returned if the operation is successfully executed.
** Otherwise, if an error is encountered (i.e. an IO error or database
** corruption) an SQLite error code is returned.
*/
SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){
i64 nEntry = 0; /* Value to return in *pnEntry */
int rc; /* Return code */
/* If this is a leaf page or the tree is not an int-key tree, then
** this page contains countable entries. Increment the entry counter
** accordingly.
*/
pPage = pCur->apPage[pCur->iPage];
if( pPage->leaf || !pPage->intKey ){
nEntry += pPage->nCell;
}
/* pPage is a leaf node. This loop navigates the cursor so that it
** points to the first interior cell that it points to the parent of
** the next page in the tree that has not yet been visited. The
** pCur->aiIdx[pCur->iPage] value is set to the index of the parent cell
** of the page, or to the number of cells in the page if the next page
** to visit is the right-child of its parent.
**
** If all pages in the tree have been visited, return SQLITE_OK to the
** caller.
*/
if( pPage->leaf ){
*pnEntry = nEntry;
return moveToRoot(pCur);
}
moveToParent(pCur);
}while ( pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell );
pCur->aiIdx[pCur->iPage]++;
pPage = pCur->apPage[pCur->iPage];
}
/* Descend to the child node of the cell that the cursor currently
** points at. This is the right-child if (iIdx==pPage->nCell).
*/
iIdx = pCur->aiIdx[pCur->iPage];
if( iIdx==pPage->nCell ){
rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
}else{
rc = moveToChild(pCur, get4byte(findCell(pPage, iIdx)));
}
}
rc = setSharedCacheTableLock(p, iTab, lockType);
}
sqlite3BtreeLeave(p);
}
return rc;
}
#endif
#ifndef SQLITE_OMIT_INCRBLOB
/*
** Argument pCsr must be a cursor opened for writing on an
** INTKEY table currently pointing at a valid table entry.
** This function modifies the data stored as part of that entry.
**
** Only the data content may only be modified, it is not possible to
** change the length of the data stored. If this function is called with
** parameters that attempt to write past the end of the existing data,
** no modifications are made and SQLITE_CORRUPT is returned.
*/
SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
int rc;
assert( cursorHoldsMutex(pCsr) );
assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );
assert( pCsr->curFlags & BTCF_Incrblob );
rc = restoreCursorPosition(pCsr);
if( rc!=SQLITE_OK ){
return rc;
}
assert( pCsr->eState!=CURSOR_REQUIRESEEK );
if( pCsr->eState!=CURSOR_VALID ){
return SQLITE_ABORT;
}
/* Save the positions of all other cursors open on this table. This is
** required in case any of them are holding references to an xFetch
** version of the b-tree page modified by the accessPayload call below.
**
** Note that pCsr must be open on a INTKEY table and saveCursorPosition()
** and hence saveAllCursors() cannot fail on a BTREE_INTKEY table, hence
** saveAllCursors can only return SQLITE_OK.
*/
VVA_ONLY(rc =) saveAllCursors(pCsr->pBt, pCsr->pgnoRoot, pCsr);
assert( rc==SQLITE_OK );
/* Check some assumptions:
** (a) the cursor is open for writing,
** (b) there is a read/write transaction open,
** (c) the connection holds a write-lock on the table (if required),
** (d) there are no conflicting read-locks, and
** (e) the cursor points at a valid row of an intKey table.
*/
if( (pCsr->curFlags & BTCF_WriteFlag)==0 ){
return SQLITE_READONLY;
}
assert( (pCsr->pBt->btsFlags & BTS_READ_ONLY)==0
&& pCsr->pBt->inTransaction==TRANS_WRITE );
assert( hasSharedCacheTableLock(pCsr->pBtree, pCsr->pgnoRoot, 0, 2) );
assert( !hasReadConflicts(pCsr->pBtree, pCsr->pgnoRoot) );
assert( pCsr->apPage[pCsr->iPage]->intKey );
return accessPayload(pCsr, offset, amt, (unsigned char *)z, 1);
}
/*
** Mark this cursor as an incremental blob cursor.
*/
SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *pCur){
pCur->curFlags |= BTCF_Incrblob;
}
#endif
/*
** Set both the "read version" (single byte at byte offset 18) and
** "write version" (single byte at byte offset 19) fields in the database
** header to iVersion.
}
}
}
}
pBt->btsFlags &= ~BTS_NO_WAL;
return rc;
}
/*
** set the mask of hint flags for cursor pCsr. Currently the only valid
** values are 0 and BTREE_BULKLOAD.
*/
SQLITE_PRIVATE void sqlite3BtreeCursorHints(BtCursor *pCsr, unsigned int mask){
assert( mask==BTREE_BULKLOAD || mask==0 );
pCsr->hints = mask;
}
/*
** Return true if the given Btree is read-only.
*/
** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back
** to its initial state after it has been run.
*/
SQLITE_PRIVATE void sqlite3VdbeMakeReady(
Vdbe *p, /* The VDBE */
Parse *pParse /* Parsing context */
){
sqlite3 *db; /* The database connection */
int nVar; /* Number of parameters */
int nMem; /* Number of VM memory registers */
int nCursor; /* Number of cursors required */
int nArg; /* Number of arguments in subprograms */
int nOnce; /* Number of OP_Once instructions */
int n; /* Loop counter */
u8 *zCsr; /* Memory available for allocation */
u8 *zEnd; /* First byte past allocated memory */
int nByte; /* How much extra memory is needed */
assert( p!=0 );
assert( p->nOp>0 );
assert( pParse!=0 );
assert( pParse==p->pParse );
db = p->db;
assert( db->mallocFailed==0 );
nVar = pParse->nVar;
nMem = pParse->nMem;
nCursor = pParse->nTab;
nArg = pParse->nMaxArg;
nOnce = pParse->nOnce;
if( nOnce==0 ) nOnce = 1; /* Ensure at least one byte in p->aOnceFlag[] */
/* For each cursor required, also allocate a memory cell. Memory
** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
** the vdbe program. Instead they are used to allocate space for
** VdbeCursor/BtCursor structures. The blob of memory associated with
** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
** stores the blob of memory associated with cursor 1, etc.
**
** See also: allocateCursor().
*/
nMem += nCursor;
/* Allocate space for memory registers, SQL variables, VDBE cursors and
** an array to marshal SQL function arguments in.
*/
zCsr = (u8*)&p->aOp[p->nOp]; /* Memory avaliable for allocation */
zEnd = (u8*)&p->aOp[pParse->nOpAlloc]; /* First byte past end of zCsr[] */
resolveP2Values(p, &nArg);
p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
if( pParse->explain && nMem<10 ){
nMem = 10;
}
memset(zCsr, 0, zEnd-zCsr);
zCsr += (zCsr - (u8*)0)&7;
assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
p->expired = 0;
/* Memory for registers, parameters, cursor, etc, is allocated in two
** passes. On the first pass, we try to reuse unused space at the
** end of the opcode array. If we are unable to satisfy all memory
** requirements by reusing the opcode array tail, then the second
** pass will fill in the rest using a fresh allocation.
**
** This two-pass approach that reuses as much memory as possible from
** the leftover space at the end of the opcode array can significantly
** reduce the amount of memory held by a prepared statement.
*/
do {
for(n=1; n<=nMem; n++){
p->aMem[n].flags = MEM_Undefined;
p->aMem[n].db = db;
}
}
p->explain = pParse->explain;
sqlite3VdbeRewind(p);
}
/*
** Close a VDBE cursor and release all the resources that cursor
** happens to hold.
*/
SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
if( pCx==0 ){
return;
}
sqlite3VdbeSorterClose(p->db, pCx);
if( pCx->pBt ){
sqlite3BtreeClose(pCx->pBt);
/* The pCx->pCursor will be close automatically, if it exists, by
** the call above. */
}else if( pCx->pCursor ){
sqlite3BtreeCloseCursor(pCx->pCursor);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
else if( pCx->pVtabCursor ){
sqlite3_vtab_cursor *pVtabCursor = pCx->pVtabCursor;
const sqlite3_module *pModule = pVtabCursor->pVtab->pModule;
p->inVtabMethod = 1;
pModule->xClose(pVtabCursor);
p->inVtabMethod = 0;
}
#endif
}
/*
** Copy the values stored in the VdbeFrame structure to its Vdbe. This
v->nMem = pFrame->nMem;
v->apCsr = pFrame->apCsr;
v->nCursor = pFrame->nCursor;
v->db->lastRowid = pFrame->lastRowid;
v->nChange = pFrame->nChange;
v->db->nChange = pFrame->nDbChange;
return pFrame->pc;
}
/*
** Close all cursors.
**
** Also release any dynamic memory held by the VM in the Vdbe.aMem memory
** cell array. This is necessary as the memory cell array may contain
** pointers to VdbeFrame objects, which may in turn contain pointers to
** open cursors.
*/
static void closeAllCursors(Vdbe *p){
if( p->pFrame ){
VdbeFrame *pFrame;
for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
sqlite3VdbeFrameRestore(pFrame);
p->pFrame = 0;
p->nFrame = 0;
}
assert( p->nFrame==0 );
}
if( p->pNext ){
p->pNext->pPrev = p->pPrev;
}
p->magic = VDBE_MAGIC_DEAD;
p->db = 0;
sqlite3DbFree(db, p);
}
/*
** The cursor "p" has a pending seek operation that has not yet been
** carried out. Seek the cursor now. If an error occurs, return
** the appropriate error code.
*/
static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
int res, rc;
#ifdef SQLITE_TEST
extern int sqlite3_search_count;
#endif
assert( p->deferredMoveto );
assert( p->isTable );
rc = sqlite3BtreeMovetoUnpacked(p->pCursor, 0, p->movetoTarget, 0, &res);
if( res!=0 ) return SQLITE_CORRUPT_BKPT;
#ifdef SQLITE_TEST
sqlite3_search_count++;
#endif
p->deferredMoveto = 0;
p->cacheStatus = CACHE_STALE;
return SQLITE_OK;
}
/*
** Something has moved cursor "p" out of place. Maybe the row it was
** pointed to was deleted out from under it. Or maybe the btree was
** rebalanced. Whatever the cause, try to restore "p" to the place it
** is supposed to be pointing. If the row was deleted out from under the
** cursor, set the cursor to point to a NULL row.
*/
static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
int isDifferentRow, rc;
assert( p->pCursor!=0 );
assert( sqlite3BtreeCursorHasMoved(p->pCursor) );
rc = sqlite3BtreeCursorRestore(p->pCursor, &isDifferentRow);
p->cacheStatus = CACHE_STALE;
if( isDifferentRow ) p->nullRow = 1;
return rc;
}
/*
** Check to ensure that the cursor is valid. Restore the cursor
** if need be. Return any I/O error from the restore operation.
*/
SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor *p){
if( sqlite3BtreeCursorHasMoved(p->pCursor) ){
return handleMovedCursor(p);
}
return SQLITE_OK;
}
/*
** Make sure the cursor p is ready to read or write the row to which it
** was last positioned. Return an error code if an OOM fault or I/O error
** prevents us from positioning the cursor to its correct position.
**
** If a MoveTo operation is pending on the given cursor, then do that
** MoveTo now. If no move is pending, check to see if the row has been
** deleted out from under the cursor and if it has, mark the row as
** a NULL row.
**
** If the cursor is already pointing to the correct row and that row has
** not been deleted out from under the cursor, then this routine is a no-op.
*/
SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){
if( p->deferredMoveto ){
return handleDeferredMoveto(p);
}
if( p->pCursor && sqlite3BtreeCursorHasMoved(p->pCursor) ){
return handleMovedCursor(p);
}
return SQLITE_OK;
}
/* Jump here if database corruption is detected after m has been
** allocated. Free the m object and return SQLITE_CORRUPT. */
idx_rowid_corruption:
testcase( m.szMalloc!=0 );
sqlite3VdbeMemRelease(&m);
return SQLITE_CORRUPT_BKPT;
}
/*
** Compare the key of the index entry that cursor pC is pointing to against
** the key string in pUnpacked. Write into *pRes a number
** that is negative, zero, or positive if pC is less than, equal to,
** or greater than pUnpacked. Return SQLITE_OK on success.
**
** pUnpacked is either created without a rowid or is truncated so that it
** omits the rowid at the end. The rowid at the end of the index entry
** is ignored as well. Hence, this routine only compares the prefixes
** of the keys prior to the final rowid, not the entire key.
*/
SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(
sqlite3 *db, /* Database connection */
VdbeCursor *pC, /* The cursor to compare against */
UnpackedRecord *pUnpacked, /* Unpacked version of key */
int *res /* Write the comparison result here */
){
i64 nCellKey = 0;
int rc;
BtCursor *pCur = pC->pCursor;
Mem m;
assert( sqlite3BtreeCursorIsValid(pCur) );
VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
** be changed out from under the copy. This macro verifies that nothing
** like that ever happens.
*/
#ifdef SQLITE_DEBUG
# define memAboutToChange(P,M) sqlite3VdbeMemAboutToChange(P,M)
#else
# define memAboutToChange(P,M)
#endif
/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes. The test
** procedures use this information to make sure that indices are
** working correctly. This variable has no function other than to
** help verify the correct operation of the library.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_search_count = 0;
#endif
/*
** knowing it.
**
** This routine converts an ephemeral string into a dynamically allocated
** string that the register itself controls. In other words, it
** converts an MEM_Ephem string into a string with P.z==P.zMalloc.
*/
#define Deephemeralize(P) \
if( ((P)->flags&MEM_Ephem)!=0 \
&& sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
/* Return true if the cursor was opened using the OP_OpenSorter opcode. */
#define isSorter(x) ((x)->pSorter!=0)
/*
** Allocate VdbeCursor number iCur. Return a pointer to it. Return NULL
** if we run out of memory.
*/
static VdbeCursor *allocateCursor(
Vdbe *p, /* The virtual machine */
int iCur, /* Index of the new VdbeCursor */
int nField, /* Number of fields in the table or index */
int iDb, /* Database the cursor belongs to, or -1 */
int isBtreeCursor /* True for B-Tree. False for pseudo-table or vtab */
){
/* Find the memory cell that will be used to store the blob of memory
** required for this VdbeCursor structure. It is convenient to use a
** vdbe memory cell to manage the memory allocation required for a
** VdbeCursor structure for the following reasons:
**
** * Sometimes cursor numbers are used for a couple of different
** purposes in a vdbe program. The different uses might require
** different sized allocations. Memory cells provide growable
** allocations.
**
** * When using ENABLE_MEMORY_MANAGEMENT, memory cell buffers can
** be freed lazily via the sqlite3_release_memory() API. This
** minimizes the number of malloc calls made by the system.
**
** Memory cells for cursors are allocated at the top of the address
** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
** cursor 1 is managed by memory cell (p->nMem-1), etc.
*/
Mem *pMem = &p->aMem[p->nMem-iCur];
int nByte;
VdbeCursor *pCx = 0;
nByte =
ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField +
(isBtreeCursor?sqlite3BtreeCursorSize():0);
assert( iCur<p->nCursor );
** The P5 parameter should be 1.
*/
case OP_HaltIfNull: { /* in3 */
pIn3 = &aMem[pOp->p3];
if( (pIn3->flags & MEM_Null)==0 ) break;
/* Fall through into OP_Halt */
}
/* Opcode: Halt P1 P2 * P4 P5
**
** Exit immediately. All open cursors, etc are closed
** automatically.
**
** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
** or sqlite3_finalize(). For a normal halt, this should be SQLITE_OK (0).
** For errors, it can be some other value. If P1!=0 then P2 will determine
** whether or not to rollback the current transaction. Do not rollback
** if P2==OE_Fail. Do the rollback if P2==OE_Rollback. If P2==OE_Abort,
** then back out all changes that have occurred during this execution of the
** VDBE, but do not rollback the transaction.
**
**
** The statement transaction is never a top-level transaction. Hence
** the RELEASE call below can never fail.
*/
assert( p->iStatement==0 || db->flags&SQLITE_CountRows );
rc = sqlite3VdbeCloseStatement(p, SAVEPOINT_RELEASE);
if( NEVER(rc!=SQLITE_OK) ){
break;
}
/* Invalidate all ephemeral cursor row caches */
p->cacheCtr = (p->cacheCtr + 2)|1;
/* Make sure the results of the current row are \000 terminated
** and have an assigned type. The results are de-ephemeralized as
** a side effect.
*/
pMem = p->pResultSet = &aMem[pOp->p1];
for(i=0; i<pOp->p2; i++){
assert( memIsValid(&pMem[i]) );
Deephemeralize(&pMem[i]);
VdbeBranchTaken( (pIn1->flags & MEM_Null)==0, 2);
if( (pIn1->flags & MEM_Null)==0 ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: Column P1 P2 P3 P4 P5
** Synopsis: r[P3]=PX
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction. (See the MakeRecord opcode for additional
** information about the format of the data.) Extract the P2-th column
** from this record. If there are less that (P2+1)
** values in the record, extract a NULL.
**
** The value extracted is stored in register P3.
**
** If the column contains fewer than P2 fields, then extract a NULL. Or,
** if the P4 argument is a P4_MEM use the value of the P4 argument as
** the result.
**
** If the OPFLAG_CLEARCACHE bit is set on P5 and P1 is a pseudo-table cursor,
** then the cache of the cursor is reset prior to extracting the column.
** The first OP_Column against a pseudo-table after the value of the content
** register has changed should have this bit set.
**
** If the OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG bits are set on P5 when
** the result is guaranteed to only be used as the argument of a length()
** or typeof() function, respectively. The loading of large blobs can be
** skipped for length() and all content loading can be skipped for typeof().
*/
case OP_Column: {
i64 payloadSize64; /* Number of bytes in the record */
int p2; /* column number to retrieve */
VdbeCursor *pC; /* The VDBE cursor */
BtCursor *pCrsr; /* The BTree cursor */
u32 *aOffset; /* aOffset[i] is offset to start of data for i-th column */
int len; /* The length of the serialized data for the column */
int i; /* Loop counter */
Mem *pDest; /* Where to write the extracted value */
Mem sMem; /* For storing the record being decoded */
const u8 *zData; /* Part of the record being decoded */
const u8 *zHdr; /* Next unparsed byte of the header */
const u8 *zEndHdr; /* Pointer to first byte after the header */
u32 offset; /* Offset into the data */
u32 szField; /* Number of bytes in the content of a field */
assert( pC!=0 );
assert( p2<pC->nField );
aOffset = pC->aOffset;
#ifndef SQLITE_OMIT_VIRTUALTABLE
assert( pC->pVtabCursor==0 ); /* OP_Column never called on virtual table */
#endif
pCrsr = pC->pCursor;
assert( pCrsr!=0 || pC->pseudoTableReg>0 ); /* pCrsr NULL on PseudoTables */
assert( pCrsr!=0 || pC->nullRow ); /* pC->nullRow on PseudoTables */
/* If the cursor cache is stale, bring it up-to-date */
rc = sqlite3VdbeCursorMoveto(pC);
if( rc ) goto abort_due_to_error;
if( pC->cacheStatus!=p->cacheCtr ){
if( pC->nullRow ){
if( pCrsr==0 ){
assert( pC->pseudoTableReg>0 );
pReg = &aMem[pC->pseudoTableReg];
assert( pReg->flags & MEM_Blob );
assert( memIsValid(pReg) );
pC->payloadSize = pC->szRow = avail = pReg->n;
goto op_column_error;
}
sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);
pDest->flags &= ~MEM_Ephem;
}
}
pDest->enc = encoding;
op_column_out:
/* If the column value is an ephemeral string, go ahead and persist
** that string in case the cursor moves before the column value is
** used. The following code does the equivalent of Deephemeralize()
** but does it faster. */
if( (pDest->flags & MEM_Ephem)!=0 && pDest->z ){
fx = pDest->flags & (MEM_Str|MEM_Blob);
assert( fx!=0 );
zData = (const u8*)pDest->z;
len = pDest->n;
if( sqlite3VdbeMemClearAndResize(pDest, len+2) ) goto no_mem;
memcpy(pDest->z, zData, len);
pDest->z[len] = 0;
pOut->enc = SQLITE_UTF8; /* In case the blob is ever converted to text */
REGISTER_TRACE(pOp->p3, pOut);
UPDATE_MAX_BLOBSIZE(pOut);
break;
}
/* Opcode: Count P1 P2 * * *
** Synopsis: r[P2]=count()
**
** Store the number of entries (an integer value) in the table or index
** opened by cursor P1 in register P2
*/
#ifndef SQLITE_OMIT_BTREECOUNT
case OP_Count: { /* out2-prerelease */
i64 nEntry;
BtCursor *pCrsr;
pCrsr = p->apCsr[pOp->p1]->pCursor;
assert( pCrsr );
nEntry = 0; /* Not needed. Only used to silence a warning. */
rc = sqlite3BtreeCount(pCrsr, &nEntry);
/* Opcode: ReadCookie P1 P2 P3 * *
**
** Read cookie number P3 from database P1 and write it into register P2.
** P3==1 is the schema version. P3==2 is the database format.
** P3==3 is the recommended pager cache size, and so forth. P1==0 is
** the main database file and P1==1 is the database file used to store
** temporary tables.
**
** There must be a read-lock on the database (either a transaction
** must be started or there must be an open cursor) before
** executing this instruction.
*/
case OP_ReadCookie: { /* out2-prerelease */
int iMeta;
int iDb;
int iCookie;
assert( p->bIsReader );
iDb = pOp->p1;
iCookie = pOp->p3;
** schema is changed. Ticket #1644 */
sqlite3ExpirePreparedStatements(db);
p->expired = 0;
}
break;
}
/* Opcode: OpenRead P1 P2 P3 P4 P5
** Synopsis: root=P2 iDb=P3
**
** Open a read-only cursor for the database table whose root page is
** P2 in a database file. The database file is determined by P3.
** P3==0 means the main database, P3==1 means the database used for
** temporary tables, and P3>1 means used the corresponding attached
** database. Give the new cursor an identifier of P1. The P1
** values need not be contiguous but all P1 values should be small integers.
** It is an error for P1 to be negative.
**
** If P5!=0 then use the content of register P2 as the root page, not
** the value of P2 itself.
**
** There will be a read lock on the database whenever there is an
** open cursor. If the database was unlocked prior to this instruction
** then a read lock is acquired as part of this instruction. A read
** lock allows other processes to read the database but prohibits
** any other process from modifying the database. The read lock is
** released when all cursors are closed. If this instruction attempts
** to get a read lock but fails, the script terminates with an
** SQLITE_BUSY error code.
**
** The P4 value may be either an integer (P4_INT32) or a pointer to
** a KeyInfo structure (P4_KEYINFO). If it is a pointer to a KeyInfo
** structure, then said structure defines the content and collating
** sequence of the index being opened. Otherwise, if P4 is an integer
** value, it is set to the number of columns in the table.
**
** See also: OpenWrite, ReopenIdx
*/
/* Opcode: ReopenIdx P1 P2 P3 P4 P5
** Synopsis: root=P2 iDb=P3
**
** The ReopenIdx opcode works exactly like ReadOpen except that it first
** checks to see if the cursor on P1 is already open with a root page
** number of P2 and if it is this opcode becomes a no-op. In other words,
** if the cursor is already open, do not reopen it.
**
** The ReopenIdx opcode may only be used with P5==0 and with P4 being
** a P4_KEYINFO object. Furthermore, the P3 value must be the same as
** every other ReopenIdx or OpenRead for the same cursor number.
**
** See the OpenRead opcode documentation for additional information.
*/
/* Opcode: OpenWrite P1 P2 P3 P4 P5
** Synopsis: root=P2 iDb=P3
**
** Open a read/write cursor named P1 on the table or index whose root
** page is P2. Or if P5!=0 use the content of register P2 to find the
** root page.
**
** The P4 value may be either an integer (P4_INT32) or a pointer to
** a KeyInfo structure (P4_KEYINFO). If it is a pointer to a KeyInfo
** structure, then said structure defines the content and collating
** sequence of the index being opened. Otherwise, if P4 is an integer
** value, it is set to the number of columns in the table, or to the
** largest index of any column of the table that is actually used.
**
** This instruction works just like OpenRead except that it opens the cursor
** in read/write mode. For a given table, there can be one or more read-only
** cursors or a single read/write cursor but not both.
**
** See also OpenRead.
*/
case OP_ReopenIdx: {
VdbeCursor *pCur;
assert( pOp->p5==0 );
assert( pOp->p4type==P4_KEYINFO );
pCur = p->apCsr[pOp->p1];
if( pCur && pCur->pgnoRoot==(u32)pOp->p2 ){
assert( pCur->iDb==pOp->p3 ); /* Guaranteed by the code generator */
break;
}
/* If the cursor is not currently open or is open on a different
** index, then fall through into OP_OpenRead to force a reopen */
}
case OP_OpenRead:
case OP_OpenWrite: {
int nField;
KeyInfo *pKeyInfo;
int p2;
int iDb;
int wrFlag;
Btree *pX;
** SQLite used to check if the root-page flags were sane at this point
** and report database corruption if they were not, but this check has
** since moved into the btree layer. */
pCur->isTable = pOp->p4type!=P4_KEYINFO;
break;
}
/* Opcode: OpenEphemeral P1 P2 * P4 P5
** Synopsis: nColumn=P2
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if
** the main database is read-only. The ephemeral
** table is deleted automatically when the cursor is closed.
**
** P2 is the number of columns in the ephemeral table.
** The cursor points to a BTree table if P4==0 and to a BTree index
** if P4 is not 0. If P4 is not NULL, it points to a KeyInfo structure
** that defines the format of keys in the index.
**
** The P5 parameter can be a mask of the BTREE_* flags defined
** in btree.h. These flags control aspects of the operation of
** the btree. The BTREE_OMIT_JOURNAL and BTREE_SINGLE flags are
** added automatically.
*/
/* Opcode: OpenAutoindex P1 P2 * P4 *
** Synopsis: nColumn=P2
pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
if( pCx==0 ) goto no_mem;
pCx->pKeyInfo = pOp->p4.pKeyInfo;
assert( pCx->pKeyInfo->db==db );
assert( pCx->pKeyInfo->enc==ENC(db) );
rc = sqlite3VdbeSorterInit(db, pOp->p3, pCx);
break;
}
/* Opcode: SequenceTest P1 P2 * * *
** Synopsis: if( cursor[P1].ctr++ ) pc = P2
**
** P1 is a sorter cursor. If the sequence counter is currently zero, jump
** to P2. Regardless of whether or not the jump is taken, increment the
** the sequence value.
*/
case OP_SequenceTest: {
VdbeCursor *pC;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC->pSorter );
if( (pC->seqCount++)==0 ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: OpenPseudo P1 P2 P3 * *
** Synopsis: P3 columns in r[P2]
**
** Open a new cursor that points to a fake table that contains a single
** row of data. The content of that one row is the content of memory
** register P2. In other words, cursor P1 becomes an alias for the
** MEM_Blob content contained in register P2.
**
** A pseudo-table created by this opcode is used to hold a single
** row output from the sorter so that the row can be decomposed into
** individual columns using the OP_Column opcode. The OP_Column opcode
** is the only cursor opcode that works with a pseudo-table.
**
** P3 is the number of fields in the records that will be stored by
** the pseudo-table.
*/
case OP_OpenPseudo: {
VdbeCursor *pCx;
assert( pOp->p1>=0 );
assert( pOp->p3>=0 );
pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
if( pCx==0 ) goto no_mem;
pCx->nullRow = 1;
pCx->pseudoTableReg = pOp->p2;
pCx->isTable = 1;
assert( pOp->p5==0 );
break;
}
/* Opcode: Close P1 * * * *
**
** Close a cursor previously opened as P1. If P1 is not
** currently open, this instruction is a no-op.
*/
case OP_Close: {
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
sqlite3VdbeFreeCursor(p, p->apCsr[pOp->p1]);
p->apCsr[pOp->p1] = 0;
break;
}
/* Opcode: SeekGE P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
** use the value in register P3 as the key. If cursor P1 refers
** to an SQL index, then P3 is the first in an array of P4 registers
** that are used as an unpacked index key.
**
** Reposition cursor P1 so that it points to the smallest entry that
** is greater than or equal to the key value. If there are no records
** greater than or equal to the key and P2 is not zero, then jump to P2.
**
** This opcode leaves the cursor configured to move in forward order,
** from the beginning toward the end. In other words, the cursor is
** configured to use Next, not Prev.
**
** See also: Found, NotFound, SeekLt, SeekGt, SeekLe
*/
/* Opcode: SeekGT P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
** use the value in register P3 as a key. If cursor P1 refers
** to an SQL index, then P3 is the first in an array of P4 registers
** that are used as an unpacked index key.
**
** Reposition cursor P1 so that it points to the smallest entry that
** is greater than the key value. If there are no records greater than
** the key and P2 is not zero, then jump to P2.
**
** This opcode leaves the cursor configured to move in forward order,
** from the beginning toward the end. In other words, the cursor is
** configured to use Next, not Prev.
**
** See also: Found, NotFound, SeekLt, SeekGe, SeekLe
*/
/* Opcode: SeekLT P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
** use the value in register P3 as a key. If cursor P1 refers
** to an SQL index, then P3 is the first in an array of P4 registers
** that are used as an unpacked index key.
**
** Reposition cursor P1 so that it points to the largest entry that
** is less than the key value. If there are no records less than
** the key and P2 is not zero, then jump to P2.
**
** This opcode leaves the cursor configured to move in reverse order,
** from the end toward the beginning. In other words, the cursor is
** configured to use Prev, not Next.
**
** See also: Found, NotFound, SeekGt, SeekGe, SeekLe
*/
/* Opcode: SeekLE P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
** use the value in register P3 as a key. If cursor P1 refers
** to an SQL index, then P3 is the first in an array of P4 registers
** that are used as an unpacked index key.
**
** Reposition cursor P1 so that it points to the largest entry that
** is less than or equal to the key value. If there are no records
** less than or equal to the key and P2 is not zero, then jump to P2.
**
** This opcode leaves the cursor configured to move in reverse order,
** from the end toward the beginning. In other words, the cursor is
** configured to use Prev, not Next.
**
** See also: Found, NotFound, SeekGt, SeekGe, SeekLt
*/
case OP_SeekLT: /* jump, in3 */
case OP_SeekLE: /* jump, in3 */
case OP_SeekGE: /* jump, in3 */
case OP_SeekGT: { /* jump, in3 */
int res;
int oc;
VdbeBranchTaken(res!=0,2);
if( res ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: Seek P1 P2 * * *
** Synopsis: intkey=r[P2]
**
** P1 is an open table cursor and P2 is a rowid integer. Arrange
** for P1 to move so that it points to the rowid given by P2.
**
** This is actually a deferred seek. Nothing actually happens until
** the cursor is used to read a record. That way, if no reads
** occur, no unnecessary I/O happens.
*/
case OP_Seek: { /* in2 */
VdbeCursor *pC;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pC->pCursor!=0 );
assert( pC->isTable );
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord. If
** P4>0 then register P3 is the first of P4 registers that form an unpacked
** record.
**
** Cursor P1 is on an index btree. If the record identified by P3 and P4
** is a prefix of any entry in P1 then a jump is made to P2 and
** P1 is left pointing at the matching entry.
**
** This operation leaves the cursor in a state where it can be
** advanced in the forward direction. The Next instruction will work,
** but not the Prev instruction.
**
** See also: NotFound, NoConflict, NotExists. SeekGe
*/
/* Opcode: NotFound P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord. If
** P4>0 then register P3 is the first of P4 registers that form an unpacked
** record.
**
** Cursor P1 is on an index btree. If the record identified by P3 and P4
** is not the prefix of any entry in P1 then a jump is made to P2. If P1
** does contain an entry whose prefix matches the P3/P4 record then control
** falls through to the next instruction and P1 is left pointing at the
** matching entry.
**
** This operation leaves the cursor in a state where it cannot be
** advanced in either direction. In other words, the Next and Prev
** opcodes do not work after this operation.
**
** See also: Found, NotExists, NoConflict
*/
/* Opcode: NoConflict P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord. If
** P4>0 then register P3 is the first of P4 registers that form an unpacked
** record.
**
** Cursor P1 is on an index btree. If the record identified by P3 and P4
** contains any NULL value, jump immediately to P2. If all terms of the
** record are not-NULL then a check is done to determine if any row in the
** P1 index btree has a matching key prefix. If there are no matches, jump
** immediately to P2. If there is a match, fall through and leave the P1
** cursor pointing to the matching row.
**
** This opcode is similar to OP_NotFound with the exceptions that the
** branch is always taken if any part of the search key input is NULL.
**
** This operation leaves the cursor in a state where it cannot be
** advanced in either direction. In other words, the Next and Prev
** opcodes do not work after this operation.
**
** See also: NotFound, Found, NotExists
*/
case OP_NoConflict: /* jump, in3 */
case OP_NotFound: /* jump, in3 */
case OP_Found: { /* jump, in3 */
int alreadyExists;
int ii;
}else{
VdbeBranchTaken(alreadyExists==0,2);
if( !alreadyExists ) pc = pOp->p2 - 1;
}
break;
}
/* Opcode: NotExists P1 P2 P3 * *
** Synopsis: intkey=r[P3]
**
** P1 is the index of a cursor open on an SQL table btree (with integer
** keys). P3 is an integer rowid. If P1 does not contain a record with
** rowid P3 then jump immediately to P2. If P1 does contain a record
** with rowid P3 then leave the cursor pointing at that record and fall
** through to the next instruction.
**
** The OP_NotFound opcode performs the same operation on index btrees
** (with arbitrary multi-value keys).
**
** This opcode leaves the cursor in a state where it cannot be advanced
** in either direction. In other words, the Next and Prev opcodes will
** not work following this opcode.
**
** See also: Found, NotFound, NoConflict
*/
case OP_NotExists: { /* jump, in3 */
VdbeCursor *pC;
BtCursor *pCrsr;
int res;
u64 iKey;
pC->deferredMoveto = 0;
VdbeBranchTaken(res!=0,2);
if( res!=0 ){
pc = pOp->p2 - 1;
}
pC->seekResult = res;
break;
}
/* Opcode: Sequence P1 P2 * * *
** Synopsis: r[P2]=cursor[P1].ctr++
**
** Find the next available sequence number for cursor P1.
** Write the sequence number into register P2.
** The sequence number on the cursor is incremented after this
** instruction.
*/
case OP_Sequence: { /* out2-prerelease */
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
assert( p->apCsr[pOp->p1]!=0 );
pOut->u.i = p->apCsr[pOp->p1]->seqCount++;
break;
}
/* Opcode: NewRowid P1 P2 P3 * *
** Synopsis: r[P2]=rowid
**
** Get a new integer record number (a.k.a "rowid") used as the key to a table.
** The record number is not previously used as a key in the database
** table that cursor P1 points to. The new record number is written
** written to register P2.
**
** If P3>0 then P3 is a register in the root frame of this VDBE that holds
** the largest previously generated record number. No new record numbers are
** allowed to be less than this value. When this value reaches its maximum,
** an SQLITE_FULL error is generated. The P3 register is updated with the '
** generated record number. This P3 mechanism is used to help implement the
** AUTOINCREMENT feature.
*/
case OP_NewRowid: { /* out2-prerelease */
pC->deferredMoveto = 0;
pC->cacheStatus = CACHE_STALE;
}
pOut->u.i = v;
break;
}
/* Opcode: Insert P1 P2 P3 P4 P5
** Synopsis: intkey=r[P3] data=r[P2]
**
** Write an entry into the table of cursor P1. A new entry is
** created if it doesn't already exist or the data for an existing
** entry is overwritten. The data is the value MEM_Blob stored in register
** number P2. The key is stored in register P3. The key must
** be a MEM_Int.
**
** If the OPFLAG_NCHANGE flag of P5 is set, then the row change count is
** incremented (otherwise not). If the OPFLAG_LASTROWID flag of P5 is set,
** then rowid is stored for subsequent return by the
** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
**
** If the OPFLAG_USESEEKRESULT flag of P5 is set and if the result of
** the last seek operation (OP_NotExists) was a success, then this
** operation will not attempt to find the appropriate row before doing
** the insert but will instead overwrite the row that the cursor is
** currently pointing to. Presumably, the prior OP_NotExists opcode
** has already positioned the cursor correctly. This is an optimization
** that boosts performance by avoiding redundant seeks.
**
** If the OPFLAG_ISUPDATE flag is set, then this opcode is part of an
** UPDATE operation. Otherwise (if the flag is clear) then this opcode
** is part of an INSERT operation. The difference is only important to
** the update hook.
**
** Parameter P4 may point to a string containing the table-name, or
** may be NULL. If it is not NULL, then the update-hook
** (sqlite3.xUpdateCallback) is invoked following a successful insert.
**
** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
** allocated, then ownership of P2 is transferred to the pseudo-cursor
** and register P2 becomes ephemeral. If the cursor is changed, the
** value of register P2 will then change. Make sure this does not
** cause any problems.)
**
** This instruction only works on tables. The equivalent instruction
** for indices is OP_IdxInsert.
*/
/* Opcode: InsertInt P1 P2 P3 P4 P5
** Synopsis: intkey=P3 data=r[P2]
**
** This works exactly like OP_Insert except that the key is the
op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
assert( pC->isTable );
db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
assert( pC->iDb>=0 );
}
break;
}
/* Opcode: Delete P1 P2 * P4 *
**
** Delete the record at which the P1 cursor is currently pointing.
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
** the next Next instruction will be a no-op. Hence it is OK to delete
** a record from within a Next loop.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).
**
** P1 must not be pseudo-table. It has to be a real table with
** multiple rows.
**
** If P4 is not NULL, then it is the name of the table that P1 is
** pointing to. The update hook will be invoked, if it exists.
** If P4 is not NULL then the P1 cursor must have been positioned
** using OP_NotFound prior to invoking this opcode.
*/
case OP_Delete: {
VdbeCursor *pC;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pC->pCursor!=0 ); /* Only valid for real tables, no pseudotables */
assert( pC->deferredMoveto==0 );
#ifdef SQLITE_DEBUG
/* The seek operation that positioned the cursor prior to OP_Delete will
** have also set the pC->movetoTarget field to the rowid of the row that
** is being deleted */
if( pOp->p4.z && pC->isTable ){
i64 iKey = 0;
sqlite3BtreeKeySize(pC->pCursor, &iKey);
assert( pC->movetoTarget==iKey );
}
#endif
rc = sqlite3BtreeDelete(pC->pCursor);
*/
case OP_ResetCount: {
sqlite3VdbeSetChanges(db, p->nChange);
p->nChange = 0;
break;
}
/* Opcode: SorterCompare P1 P2 P3 P4
** Synopsis: if key(P1)!=trim(r[P3],P4) goto P2
**
** P1 is a sorter cursor. This instruction compares a prefix of the
** record blob in register P3 against a prefix of the entry that
** the sorter cursor currently points to. Only the first P4 fields
** of r[P3] and the sorter record are compared.
**
** If either P3 or the sorter contains a NULL in one of their significant
** fields (not counting the P4 fields at the end which are ignored) then
** the comparison is assumed to be equal.
**
** Fall through to next instruction if the two records compare equal to
** each other. Jump to P2 if they are different.
*/
case OP_SorterCompare: {
VdbeBranchTaken(res!=0,2);
if( res ){
pc = pOp->p2-1;
}
break;
};
/* Opcode: SorterData P1 P2 P3 * *
** Synopsis: r[P2]=data
**
** Write into register P2 the current sorter data for sorter cursor P1.
** Then clear the column header cache on cursor P3.
**
** This opcode is normally use to move a record out of the sorter and into
** a register that is the source for a pseudo-table cursor created using
** OpenPseudo. That pseudo-table cursor is the one that is identified by
** parameter P3. Clearing the P3 column cache as part of this opcode saves
** us from having to issue a separate NullRow instruction to clear that cache.
*/
case OP_SorterData: {
VdbeCursor *pC;
pOut = &aMem[pOp->p2];
pC = p->apCsr[pOp->p1];
assert( isSorter(pC) );
rc = sqlite3VdbeSorterRowkey(pC, pOut);
assert( rc!=SQLITE_OK || (pOut->flags & MEM_Blob) );
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
p->apCsr[pOp->p3]->cacheStatus = CACHE_STALE;
break;
}
/* Opcode: RowData P1 P2 * * *
** Synopsis: r[P2]=data
**
** Write into register P2 the complete row data for cursor P1.
** There is no interpretation of the data.
** It is just copied onto the P2 register exactly as
** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/
/* Opcode: RowKey P1 P2 * * *
** Synopsis: r[P2]=key
**
** Write into register P2 the complete row key for cursor P1.
** There is no interpretation of the data.
** The key is copied onto the P2 register exactly as
** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/
case OP_RowKey:
case OP_RowData: {
VdbeCursor *pC;
BtCursor *pCrsr;
u32 n;
i64 n64;
pOut = &aMem[pOp->p2];
assert( pC->isTable || pOp->opcode!=OP_RowData );
assert( pC->isTable==0 || pOp->opcode==OP_RowData );
assert( pC!=0 );
assert( pC->nullRow==0 );
assert( pC->pseudoTableReg==0 );
assert( pC->pCursor!=0 );
pCrsr = pC->pCursor;
/* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
** OP_Rewind/Op_Next with no intervening instructions that might invalidate
** the cursor. If this where not the case, on of the following assert()s
** would fail. Should this ever change (because of changes in the code
** generator) then the fix would be to insert a call to
** sqlite3VdbeCursorMoveto().
*/
assert( pC->deferredMoveto==0 );
assert( sqlite3BtreeCursorIsValid(pCrsr) );
#if 0 /* Not required due to the previous to assert() statements */
rc = sqlite3VdbeCursorMoveto(pC);
if( rc!=SQLITE_OK ) goto abort_due_to_error;
#endif
}
rc = sqlite3BtreeKeySize(pC->pCursor, &v);
assert( rc==SQLITE_OK ); /* Always so because of CursorRestore() above */
}
pOut->u.i = v;
break;
}
/* Opcode: NullRow P1 * * * *
**
** Move the cursor P1 to a null row. Any OP_Column operations
** that occur while the cursor is on the null row will always
** write a NULL.
*/
case OP_NullRow: {
VdbeCursor *pC;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
pC->nullRow = 1;
pC->cacheStatus = CACHE_STALE;
}
/* Opcode: Last P1 P2 * * *
**
** The next use of the Rowid or Column or Prev instruction for P1
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
**
** This opcode leaves the cursor configured to move in reverse order,
** from the end toward the beginning. In other words, the cursor is
** configured to use Prev, not Next.
*/
case OP_Last: { /* jump */
VdbeCursor *pC;
BtCursor *pCrsr;
int res;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
/* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1
** will refer to the first entry in the database table or index.
** If the table or index is empty, jump immediately to P2.
** If the table or index is not empty, fall through to the following
** instruction.
**
** This opcode leaves the cursor configured to move in forward order,
** from the beginning toward the end. In other words, the cursor is
** configured to use Next, not Prev.
*/
case OP_Rewind: { /* jump */
VdbeCursor *pC;
BtCursor *pCrsr;
int res;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pOp->p2>0 && pOp->p2<p->nOp );
VdbeBranchTaken(res!=0,2);
if( res ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: Next P1 P2 P3 P4 P5
**
** Advance cursor P1 so that it points to the next key/data pair in its
** table or index. If there are no more key/value pairs then fall through
** to the following instruction. But if the cursor advance was successful,
** jump immediately to P2.
**
** The Next opcode is only valid following an SeekGT, SeekGE, or
** OP_Rewind opcode used to position the cursor. Next is not allowed
** to follow SeekLT, SeekLE, or OP_Last.
**
** The P1 cursor must be for a real table, not a pseudo-table. P1 must have
** been opened prior to this opcode or the program will segfault.
**
** The P3 value is a hint to the btree implementation. If P3==1, that
** means P1 is an SQL index and that this instruction could have been
** omitted if that index had been unique. P3 is usually 0. P3 is
** always either 0 or 1.
**
** P4 is always of type P4_ADVANCE. The function pointer points to
** sqlite3BtreeNext().
**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
**
** See also: Prev, NextIfOpen
*/
/* Opcode: NextIfOpen P1 P2 P3 P4 P5
**
** This opcode works just like Next except that if cursor P1 is not
** open it behaves a no-op.
*/
/* Opcode: Prev P1 P2 P3 P4 P5
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index. If there is no previous key/value pairs then fall through
** to the following instruction. But if the cursor backup was successful,
** jump immediately to P2.
**
**
** The Prev opcode is only valid following an SeekLT, SeekLE, or
** OP_Last opcode used to position the cursor. Prev is not allowed
** to follow SeekGT, SeekGE, or OP_Rewind.
**
** The P1 cursor must be for a real table, not a pseudo-table. If P1 is
** not open then the behavior is undefined.
**
** The P3 value is a hint to the btree implementation. If P3==1, that
** means P1 is an SQL index and that this instruction could have been
** omitted if that index had been unique. P3 is usually 0. P3 is
** always either 0 or 1.
**
** P4 is always of type P4_ADVANCE. The function pointer points to
** sqlite3BtreePrevious().
**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
*/
/* Opcode: PrevIfOpen P1 P2 P3 P4 P5
**
** This opcode works just like Prev except that if cursor P1 is not
** open it behaves a no-op.
*/
case OP_SorterNext: { /* jump */
VdbeCursor *pC;
int res;
pC = p->apCsr[pOp->p1];
assert( isSorter(pC) );
res = 0;
rc = sqlite3VdbeSorterNext(db, pC, &res);
** MakeRecord instructions. This opcode writes that key
** into the index P1. Data for the entry is nil.
**
** P3 is a flag that provides a hint to the b-tree layer that this
** insert is likely to be an append.
**
** If P5 has the OPFLAG_NCHANGE bit set, then the change counter is
** incremented by this instruction. If the OPFLAG_NCHANGE bit is clear,
** then the change counter is unchanged.
**
** If P5 has the OPFLAG_USESEEKRESULT bit set, then the cursor must have
** just done a seek to the spot where the new entry is to be inserted.
** This flag avoids doing an extra seek.
**
** This instruction only works for indices. The equivalent instruction
** for tables is OP_Insert.
*/
case OP_SorterInsert: /* in2 */
case OP_IdxInsert: { /* in2 */
VdbeCursor *pC;
BtCursor *pCrsr;
}
}
break;
}
/* Opcode: IdxDelete P1 P2 P3 * *
** Synopsis: key=r[P2@P3]
**
** The content of P3 registers starting at register P2 form
** an unpacked index key. This opcode removes that entry from the
** index opened by cursor P1.
*/
case OP_IdxDelete: {
VdbeCursor *pC;
BtCursor *pCrsr;
int res;
UnpackedRecord r;
assert( pOp->p3>0 );
assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem-p->nCursor)+1 );
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
}
assert( pC->deferredMoveto==0 );
pC->cacheStatus = CACHE_STALE;
break;
}
/* Opcode: IdxRowid P1 P2 * * *
** Synopsis: r[P2]=rowid
**
** Write into register P2 an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1. This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeRecord.
*/
case OP_IdxRowid: { /* out2-prerelease */
BtCursor *pCrsr;
VdbeCursor *pC;
i64 rowid;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
pCrsr = pC->pCursor;
assert( pCrsr!=0 );
pOut->flags = MEM_Null;
assert( pC->isTable==0 );
assert( pC->deferredMoveto==0 );
/* sqlite3VbeCursorRestore() can only fail if the record has been deleted
** out from under the cursor. That will never happend for an IdxRowid
** opcode, hence the NEVER() arround the check of the return value.
*/
rc = sqlite3VdbeCursorRestore(pC);
if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
if( !pC->nullRow ){
rowid = 0; /* Not needed. Only used to silence a warning. */
rc = sqlite3VdbeIdxRowid(db, pCrsr, &rowid);
if( rc!=SQLITE_OK ){
goto abort_due_to_error;
memAboutToChange(p, &aMem[pOp->p3]);
aMem[pOp->p3].u.i += nChange;
}
}
break;
}
/* Opcode: ResetSorter P1 * * * *
**
** Delete all contents from the ephemeral table or sorter
** that is open on cursor P1.
**
** This opcode only works for cursors used for sorting and
** opened with OP_OpenEphemeral or OP_SorterOpen.
*/
case OP_ResetSorter: {
VdbeCursor *pC;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
if( pC->pSorter ){
sqlite3VdbeSorterReset(db, pC->pSorter);
break;
}
/* Register pRt is used to store the memory required to save the state
** of the current program, and the memory required at runtime to execute
** the trigger program. If this trigger has been fired before, then pRt
** is already allocated. Otherwise, it must be initialized. */
if( (pRt->flags&MEM_Frame)==0 ){
/* SubProgram.nMem is set to the number of memory cells used by the
** program stored in SubProgram.aOp. As well as these, one memory
** cell is required for each cursor used by the program. Set local
** variable nMem (and later, VdbeFrame.nChildMem) to this value.
*/
nMem = pProgram->nMem + pProgram->nCsr;
nByte = ROUND8(sizeof(VdbeFrame))
+ nMem * sizeof(Mem)
+ pProgram->nCsr * sizeof(VdbeCursor *)
+ pProgram->nOnce * sizeof(u8);
pFrame = sqlite3DbMallocZero(db, nByte);
if( !pFrame ){
goto no_mem;
rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
p->inVtabMethod = 0;
break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VOpen P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number. This opcode opens a cursor to the virtual
** table and stores that cursor in P1.
*/
case OP_VOpen: {
VdbeCursor *pCur;
sqlite3_vtab_cursor *pVtabCursor;
sqlite3_vtab *pVtab;
sqlite3_module *pModule;
assert( p->bIsReader );
pCur = 0;
pVtabCursor = 0;
pVtab = pOp->p4.pVtab->pVtab;
pModule = (sqlite3_module *)pVtab->pModule;
assert(pVtab && pModule);
rc = pModule->xOpen(pVtab, &pVtabCursor);
sqlite3VtabImportErrmsg(p, pVtab);
if( SQLITE_OK==rc ){
/* Initialize sqlite3_vtab_cursor base class */
pVtabCursor->pVtab = pVtab;
/* Initialize vdbe cursor object */
pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
if( pCur ){
pCur->pVtabCursor = pVtabCursor;
}else{
db->mallocFailed = 1;
pModule->xClose(pVtabCursor);
}
}
break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VFilter P1 P2 P3 P4 *
** Synopsis: iplan=r[P3] zplan='P4'
**
** P1 is a cursor opened using VOpen. P2 is an address to jump to if
** the filtered result set is empty.
**
** P4 is either NULL or a string that was generated by the xBestIndex
** method of the module. The interpretation of the P4 string is left
** to the module implementation.
**
** This opcode invokes the xFilter method on the virtual table specified
** by P1. The integer query plan parameter to xFilter is stored in register
** P3. Register P3+1 stores the argc parameter to be passed to the
** xFilter method. Registers P3+2..P3+1+argc are the argc
** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
**
** A jump is made to P2 if the result set after filtering would be empty.
*/
case OP_VFilter: { /* jump */
int nArg;
int iQuery;
const sqlite3_module *pModule;
Mem *pQuery;
Mem *pArgc;
sqlite3_vtab_cursor *pVtabCursor;
sqlite3_vtab *pVtab;
VdbeCursor *pCur;
int res;
int i;
Mem **apArg;
pQuery = &aMem[pOp->p3];
pArgc = &pQuery[1];
pCur = p->apCsr[pOp->p1];
assert( memIsValid(pQuery) );
break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VColumn P1 P2 P3 * *
** Synopsis: r[P3]=vcolumn(P2)
**
** Store the value of the P2-th column of
** the row of the virtual-table that the
** P1 cursor is pointing to into register P3.
*/
case OP_VColumn: {
sqlite3_vtab *pVtab;
const sqlite3_module *pModule;
Mem *pDest;
sqlite3_context sContext;
VdbeCursor *pCur = p->apCsr[pOp->p1];
assert( pCur->pVtabCursor );
assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
break;
}
pVtab = pCur->pVtabCursor->pVtab;
pModule = pVtab->pModule;
assert( pModule->xNext );
/* Invoke the xNext() method of the module. There is no way for the
** underlying implementation to return an error if one occurs during
** xNext(). Instead, if an error occurs, true is returned (indicating that
** data is available) and the error code returned when xColumn or
** some other method is next invoked on the save virtual table cursor.
*/
p->inVtabMethod = 1;
rc = pModule->xNext(pCur->pVtabCursor);
p->inVtabMethod = 0;
sqlite3VtabImportErrmsg(p, pVtab);
if( rc==SQLITE_OK ){
res = pModule->xEof(pCur->pVtabCursor);
}
VdbeBranchTaken(!res,2);
if( !res ){
#ifndef SQLITE_OMIT_INCRBLOB
/*
** Valid sqlite3_blob* handles point to Incrblob structures.
*/
typedef struct Incrblob Incrblob;
struct Incrblob {
int flags; /* Copy of "flags" passed to sqlite3_blob_open() */
int nByte; /* Size of open blob, in bytes */
int iOffset; /* Byte offset of blob in cursor data */
int iCol; /* Table column this handle is open on */
BtCursor *pCsr; /* Cursor pointing at blob row */
sqlite3_stmt *pStmt; /* Statement holding cursor open */
sqlite3 *db; /* The associated database */
};
/*
** This function is used by both blob_open() and blob_reopen(). It seeks
** the b-tree cursor associated with blob handle p to point to row iRow.
** If successful, SQLITE_OK is returned and subsequent calls to
** sqlite3_blob_read() or sqlite3_blob_write() access the specified row.
**
** If an error occurs, or if the specified row does not exist or does not
** contain a value of type TEXT or BLOB in the column nominated when the
** blob handle was opened, then an error code is returned and *pzErr may
** be set to point to a buffer containing an error message. It is the
** responsibility of the caller to free the error message buffer using
** sqlite3DbFree().
**
** If an error does occur, then the b-tree cursor is closed. All subsequent
** calls to sqlite3_blob_read(), blob_write() or blob_reopen() will
** immediately return SQLITE_ABORT.
*/
static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
int rc; /* Error code */
char *zErr = 0; /* Error message */
Vdbe *v = (Vdbe *)p->pStmt;
/* Set the value of the SQL statements only variable to integer iRow.
** This is done directly instead of using sqlite3_bind_int64() to avoid
const char *zDb, /* The attached database containing the blob */
const char *zTable, /* The table containing the blob */
const char *zColumn, /* The column containing the blob */
sqlite_int64 iRow, /* The row containing the glob */
int flags, /* True -> read/write access, false -> read-only */
sqlite3_blob **ppBlob /* Handle for accessing the blob returned here */
){
int nAttempt = 0;
int iCol; /* Index of zColumn in row-record */
/* This VDBE program seeks a btree cursor to the identified
** db/table/row entry. The reason for using a vdbe program instead
** of writing code to use the b-tree layer directly is that the
** vdbe program will take advantage of the various transaction,
** locking and error handling infrastructure built into the vdbe.
**
** After seeking the cursor, the vdbe executes an OP_ResultRow.
** Code external to the Vdbe then "borrows" the b-tree cursor and
** uses it to implement the blob_read(), blob_write() and
** blob_bytes() functions.
**
** The sqlite3_blob_close() function finalizes the vdbe program,
** which closes the b-tree cursor and (possibly) commits the
** transaction.
*/
static const int iLn = VDBE_OFFSET_LINENO(4);
static const VdbeOpList openBlob[] = {
/* {OP_Transaction, 0, 0, 0}, // 0: Inserted separately */
{OP_TableLock, 0, 0, 0}, /* 1: Acquire a read or write lock */
/* One of the following two instructions is replaced by an OP_Noop. */
{OP_OpenRead, 0, 0, 0}, /* 2: Open cursor 0 for reading */
{OP_OpenWrite, 0, 0, 0}, /* 3: Open cursor 0 for read/write */
{OP_Variable, 1, 1, 1}, /* 4: Push the rowid to the stack */
{OP_NotExists, 0, 10, 1}, /* 5: Seek the cursor */
{OP_Column, 0, 0, 1}, /* 6 */
{OP_ResultRow, 1, 0, 0}, /* 7 */
{OP_Goto, 0, 4, 0}, /* 8 */
{OP_Close, 0, 0, 0}, /* 9 */
{OP_Halt, 0, 0, 0}, /* 10 */
};
int rc = SQLITE_OK;
char *zErr = 0;
Table *pTab;
sqlite3VdbeChangeP3(v, 1, flags);
sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);
#endif
/* Remove either the OP_OpenWrite or OpenRead. Set the P2
** parameter of the other to pTab->tnum. */
sqlite3VdbeChangeToNoop(v, 3 - flags);
sqlite3VdbeChangeP2(v, 2 + flags, pTab->tnum);
sqlite3VdbeChangeP3(v, 2 + flags, iDb);
/* Configure the number of columns. Configure the cursor to
** think that the table has one more column than it really
** does. An OP_Column to retrieve this imaginary column will
** always return an SQL NULL. This is useful because it means
** we can invoke OP_Column to fill in the vdbe cursors type
** and offset cache without causing any IO.
*/
sqlite3VdbeChangeP4(v, 2+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
sqlite3VdbeChangeP2(v, 6, pTab->nCol);
if( !db->mallocFailed ){
pParse->nVar = 1;
pParse->nMem = 1;
pParse->nTab = 1;
sqlite3VdbeMakeReady(v, pParse);
}
**
** sqlite3VdbeSorterWrite() Add a single new row to the VdbeSorter
** object. The row is a binary blob in the
** OP_MakeRecord format that contains both
** the ORDER BY key columns and result columns
** in the case of a SELECT w/ ORDER BY, or
** the complete record for an index entry
** in the case of a CREATE INDEX.
**
** sqlite3VdbeSorterRewind() Sort all content previously added.
** Position the read cursor on the
** first sorted element.
**
** sqlite3VdbeSorterNext() Advance the read cursor to the next sorted
** element.
**
** sqlite3VdbeSorterRowkey() Return the complete binary blob for the
** row currently under the read cursor.
**
** sqlite3VdbeSorterCompare() Compare the binary blob for the row
** currently under the read cursor against
** another binary blob X and report if
** X is strictly less than the read cursor.
** Used to enforce uniqueness in a
** CREATE UNIQUE INDEX statement.
**
** sqlite3VdbeSorterClose() Close the VdbeSorter object and reclaim
** all resources.
**
** sqlite3VdbeSorterReset() Refurbish the VdbeSorter for reuse. This
** is like Close() followed by Init() only
** much faster.
**
VdbeSorter *pSorter; /* Sorter that owns this sub-task */
UnpackedRecord *pUnpacked; /* Space to unpack a record */
SorterList list; /* List for thread to write to a PMA */
int nPMA; /* Number of PMAs currently in file */
SorterFile file; /* Temp file for level-0 PMAs */
SorterFile file2; /* Space for other PMAs */
};
/*
** Main sorter structure. A single instance of this is allocated for each
** sorter cursor created by the VDBE.
**
** mxKeysize:
** As records are added to the sorter by calls to sqlite3VdbeSorterWrite(),
** this variable is updated so as to be set to the size on disk of the
** largest record in the sorter.
*/
struct VdbeSorter {
int mnPmaSize; /* Minimum PMA size, in bytes */
int mxPmaSize; /* Maximum PMA size, in bytes. 0==no limit */
int mxKeysize; /* Largest serialized key seen so far */
return rc;
}
/*
** Attach PmaReader pReadr to file pFile (if it is not already attached to
** that file) and seek it to offset iOff within the file. Return SQLITE_OK
** if successful, or an SQLite error code if an error occurs.
*/
static int vdbePmaReaderSeek(
SortSubtask *pTask, /* Task context */
PmaReader *pReadr, /* Reader whose cursor is to be moved */
SorterFile *pFile, /* Sorter file to read from */
i64 iOff /* Offset in pFile */
){
int rc = SQLITE_OK;
assert( pReadr->pIncr==0 || pReadr->pIncr->bEof==0 );
if( sqlite3FaultSim(201) ) return SQLITE_IOERR_READ;
if( pReadr->aMap ){
sqlite3OsUnfetch(pReadr->pFd, 0, pReadr->aMap);
const void *pKey2, int nKey2 /* Right side of comparison */
){
UnpackedRecord *r2 = pTask->pUnpacked;
if( pKey2 ){
sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);
}
return sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
}
/*
** Initialize the temporary index cursor just opened as a sorter cursor.
**
** Usually, the sorter module uses the value of (pCsr->pKeyInfo->nField)
** to determine the number of fields that should be compared from the
** records being sorted. However, if the value passed as argument nField
** is non-zero and the sorter is able to guarantee a stable sort, nField
** is used instead. This is used when sorting records for a CREATE INDEX
** statement. In this case, keys are always delivered to the sorter in
** order of the primary key, which happens to be make up the final part
** of the records being sorted. So if the sort is stable, there is never
** any reason to compare PK fields and they can be ignored for a small
if( pIncr->aFile[0].pFd ) sqlite3OsCloseFree(pIncr->aFile[0].pFd);
if( pIncr->aFile[1].pFd ) sqlite3OsCloseFree(pIncr->aFile[1].pFd);
}
#endif
vdbeMergeEngineFree(pIncr->pMerger);
sqlite3_free(pIncr);
}
}
/*
** Reset a sorting cursor back to its original empty state.
*/
SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){
int i;
(void)vdbeSorterJoinAll(pSorter, SQLITE_OK);
assert( pSorter->bUseThreads || pSorter->pReader==0 );
#if SQLITE_MAX_WORKER_THREADS>0
if( pSorter->pReader ){
vdbePmaReaderClear(pSorter->pReader);
sqlite3DbFree(db, pSorter->pReader);
pSorter->pReader = 0;
pSorter->list.pList = 0;
pSorter->list.szPMA = 0;
pSorter->bUsePMA = 0;
pSorter->iMemory = 0;
pSorter->mxKeysize = 0;
sqlite3DbFree(db, pSorter->pUnpacked);
pSorter->pUnpacked = 0;
}
/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
VdbeSorter *pSorter = pCsr->pSorter;
if( pSorter ){
sqlite3VdbeSorterReset(db, pSorter);
sqlite3_free(pSorter->list.aMemory);
sqlite3DbFree(db, pSorter);
pCsr->pSorter = 0;
}
}
}
return rc;
#endif /* SQLITE_MAX_WORKER_THREADS!=0 */
}
/*
** Add a record to the sorter.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
const VdbeCursor *pCsr, /* Sorter cursor */
Mem *pVal /* Memory cell containing record */
){
VdbeSorter *pSorter = pCsr->pSorter;
int rc = SQLITE_OK; /* Return Code */
SorterRecord *pNew; /* New list element */
int bFlush; /* True to flush contents of memory to PMA */
int nReq; /* Bytes of memory required */
int nPMA; /* Bytes of PMA space required */
** that has already written two or more level-0 PMAs to one or more temp
** files. It builds a tree of MergeEngine/IncrMerger/PmaReader objects that
** can be used to incrementally merge all PMAs on disk.
**
** If successful, SQLITE_OK is returned and *ppOut set to point to the
** MergeEngine object at the root of the tree before returning. Or, if an
** error occurs, an SQLite error code is returned and the final value
** of *ppOut is undefined.
*/
static int vdbeSorterMergeTreeBuild(
VdbeSorter *pSorter, /* The VDBE cursor that implements the sort */
MergeEngine **ppOut /* Write the MergeEngine here */
){
MergeEngine *pMain = 0;
int rc = SQLITE_OK;
int iTask;
#if SQLITE_MAX_WORKER_THREADS>0
/* If the sorter uses more than one task, then create the top-level
** MergeEngine here. This MergeEngine will read data from exactly
** one PmaReader per sub-task. */
return SQLITE_NOMEM;
}
pOut->n = nKey;
MemSetTypeFlag(pOut, MEM_Blob);
memcpy(pOut->z, pKey, nKey);
return SQLITE_OK;
}
/*
** Compare the key in memory cell pVal with the key that the sorter cursor
** passed as the first argument currently points to. For the purposes of
** the comparison, ignore the rowid field at the end of each record.
**
** If the sorter cursor key contains any NULL values, consider it to be
** less than pVal. Even if pVal also contains NULL values.
**
** If an error occurs, return an SQLite error code (i.e. SQLITE_NOMEM).
** Otherwise, set *pRes to a negative, zero or positive value if the
** key in pVal is smaller than, equal to or larger than the current sorter
** key.
**
** This routine forms the core of the OP_SorterCompare opcode, which in
** turn is used to verify uniqueness when constructing a UNIQUE INDEX.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
const VdbeCursor *pCsr, /* Sorter cursor */
Mem *pVal, /* Value to compare to current sorter key */
int nKeyCol, /* Compare this many columns */
int *pRes /* OUT: Result of comparison */
){
VdbeSorter *pSorter = pCsr->pSorter;
UnpackedRecord *r2 = pSorter->pUnpacked;
KeyInfo *pKeyInfo = pCsr->pKeyInfo;
int i;
void *pKey; int nKey; /* Sorter key to compare pVal with */
/*
** The rollback journal is composed of a linked list of these structures.
*/
struct FileChunk {
FileChunk *pNext; /* Next chunk in the journal */
u8 zChunk[JOURNAL_CHUNKSIZE]; /* Content of this chunk */
};
/*
** An instance of this object serves as a cursor into the rollback journal.
** The cursor can be either for reading or writing.
*/
struct FilePoint {
sqlite3_int64 iOffset; /* Offset from the beginning of the file */
FileChunk *pChunk; /* Specific chunk into which cursor points */
};
/*
** This subclass is a subclass of sqlite3_file. Each open memory-journal
** is an instance of this class.
*/
struct MemJournal {
sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */
FileChunk *pFirst; /* Head of in-memory chunk-list */
FilePoint endpoint; /* Pointer to the end of the file */
}
/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr
** expression node refer back to that source column. The following changes
** are made to pExpr:
**
** pExpr->iDb Set the index in db->aDb[] of the database X
** (even if X is implied).
** pExpr->iTable Set to the cursor number for the table obtained
** from pSrcList.
** pExpr->pTab Points to the Table structure of X.Y (even if
** X and/or Y are implied.)
** pExpr->iColumn Set to the column number within the table.
** pExpr->op Set to TK_COLUMN.
** pExpr->pLeft Any expression this points to is deleted
** pExpr->pRight Any expression this points to is deleted.
**
** The zDb variable is the name of the database (the "X"). This value may be
** NULL meaning that name is of the form Y.Z or Z. Any available database
** Y: The name of a table in a FROM clause. Or in a trigger
** one of the special names "old" or "new".
**
** Z: The name of a column in table Y.
**
** The node at the root of the subtree is modified as follows:
**
** Expr.op Changed to TK_COLUMN
** Expr.pTab Points to the Table object for X.Y
** Expr.iColumn The column index in X.Y. -1 for the rowid.
** Expr.iTable The VDBE cursor number for X.Y
**
**
** To resolve result-set references, look for expression nodes of the
** form Z (with no X and Y prefix) where the Z matches the right-hand
** size of an AS clause in the result-set of a SELECT. The Z expression
** is replaced by a copy of the left-hand side of the result-set expression.
** Table-name and function resolution occurs on the substituted expression
** tree. For example, in:
**
** SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x;
pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
pItem->sortOrder = pOldItem->sortOrder;
pItem->done = 0;
pItem->bSpanIsTab = pOldItem->bSpanIsTab;
pItem->u = pOldItem->u;
}
return pNew;
}
/*
** If cursors, triggers, views and subqueries are all omitted from
** the build, then none of the following routines, except for
** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
** called with a NULL argument.
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
|| !defined(SQLITE_OMIT_SUBQUERY)
SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
SrcList *pNew;
int i;
int nByte;
** that does no originate from the ON or USING clauses of a join.
** Return 0 if it involves variables or function calls or terms from
** an ON or USING clause.
*/
SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr *p){
return exprIsConst(p, 2, 0);
}
/*
** Walk an expression tree. Return non-zero if the expression constant
** for any single row of the table with cursor iCur. In other words, the
** expression must not refer to any non-deterministic function nor any
** table other than iCur.
*/
SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr *p, int iCur){
return exprIsConst(p, 3, iCur);
}
/*
** Walk an expression tree. Return non-zero if the expression is constant
** or a function call with constant arguments. Return and 0 if there
/*
** This function is used by the implementation of the IN (...) operator.
** The pX parameter is the expression on the RHS of the IN operator, which
** might be either a list of expressions or a subquery.
**
** The job of this routine is to find or create a b-tree object that can
** be used either to test for membership in the RHS set or to iterate through
** all members of the RHS set, skipping duplicates.
**
** A cursor is opened on the b-tree object that is the RHS of the IN operator
** and pX->iTable is set to the index of that cursor.
**
** The returned value of this function indicates the b-tree type, as follows:
**
** IN_INDEX_ROWID - The cursor was opened on a database table.
** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
** IN_INDEX_EPH - The cursor was opened on a specially created and
** populated epheremal table.
** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
** implemented as a sequence of comparisons.
**
** An existing b-tree might be used if the RHS expression pX is a simple
** subquery such as:
**
** SELECT <column> FROM <table>
**
** If the RHS of the IN operator is a list or a more complex subquery, then
** an ephemeral table might need to be generated from the RHS and then
** pX->iTable made to point to the ephemeral table instead of an
Expr *pExpr, /* The IN expression */
int destIfFalse, /* Jump here if LHS is not contained in the RHS */
int destIfNull /* Jump here if the results are unknown due to NULLs */
){
int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
char affinity; /* Comparison affinity to use */
int eType; /* Type of the RHS */
int r1; /* Temporary use register */
Vdbe *v; /* Statement under construction */
/* Compute the RHS. After this step, the table with cursor
** pExpr->iTable will contains the values that make up the RHS.
*/
v = pParse->pVdbe;
assert( v!=0 ); /* OOM detected prior to this routine */
VdbeNoopComment((v, "begin IN expr"));
eType = sqlite3FindInIndex(pParse, pExpr,
IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
destIfFalse==destIfNull ? 0 : &rRhsHasNull);
/* Figure out the affinity to use to create a key from the results
}
}
}
/*
** Generate code to extract the value of the iCol-th column of a table.
*/
SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
Vdbe *v, /* The VDBE under construction */
Table *pTab, /* The table containing the value */
int iTabCur, /* The table cursor. Or the PK cursor for WITHOUT ROWID */
int iCol, /* Index of the column to extract */
int regOut /* Extract the value into this register */
){
if( iCol<0 || iCol==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
}else{
int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
int x = iCol;
if( !HasRowid(pTab) ){
x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
sqlite3ColumnDefault(v, pTab, iCol, regOut);
}
}
/*
** Generate code that will extract the iColumn-th column from
** table pTab and store the column value in a register. An effort
** is made to store the column value in register iReg, but this is
** not guaranteed. The location of the column value is returned.
**
** There must be an open cursor to pTab in iTable when this routine
** is called. If iColumn<0 then code is generated that extracts the rowid.
*/
SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(
Parse *pParse, /* Parsing and code generating context */
Table *pTab, /* Description of the table we are reading from */
int iColumn, /* Index of the table column */
int iTable, /* The cursor pointing to the table */
int iReg, /* Store results here */
u8 p5 /* P5 value for OP_Column */
){
Vdbe *v = pParse->pVdbe;
int i;
struct yColCache *p;
for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
p->lru = pParse->iCacheCnt++;
** If the sqlite_statN tables do not previously exist, it is created.
**
** Argument zWhere may be a pointer to a buffer containing a table name,
** or it may be a NULL pointer. If it is not NULL, then all entries in
** the sqlite_statN tables associated with the named table are deleted.
** If zWhere==0, then code is generated to delete all stat table entries.
*/
static void openStatTable(
Parse *pParse, /* Parsing context */
int iDb, /* The database we are looking in */
int iStatCur, /* Open the sqlite_stat1 table on this cursor */
const char *zWhere, /* Delete entries for this table or index */
const char *zWhereType /* Either "tbl" or "idx" */
){
static const struct {
const char *zName;
const char *zCols;
} aTable[] = {
{ "sqlite_stat1", "tbl,idx,stat" },
#if defined(SQLITE_ENABLE_STAT4)
{ "sqlite_stat4", "tbl,idx,neq,nlt,ndlt,sample" },
/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
Parse *pParse, /* Parser context */
Table *pTab, /* Table whose indices are to be analyzed */
Index *pOnlyIdx, /* If not NULL, only analyze this one index */
int iStatCur, /* Index of VdbeCursor that writes the sqlite_stat1 table */
int iMem, /* Available memory locations begin here */
int iTab /* Next available cursor */
){
sqlite3 *db = pParse->db; /* Database handle */
Index *pIdx; /* An index to being analyzed */
int iIdxCur; /* Cursor open on index being analyzed */
int iTabCur; /* Table cursor */
Vdbe *v; /* The virtual machine being built up */
int i; /* Loop counter */
int jZeroRows = -1; /* Jump from here if number of rows is zero */
int iDb; /* Index of database containing pTab */
u8 needTableCnt = 1; /* True to count the table */
int regNewRowid = iMem++; /* Rowid for the inserted record */
int regStat4 = iMem++; /* Register to hold Stat4Accum object */
int regChng = iMem++; /* Index of changed index field */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
int regRowid = iMem++; /* Rowid argument passed to stat_push() */
assert( iDb>=0 );
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
#ifndef SQLITE_OMIT_AUTHORIZATION
if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,
db->aDb[iDb].zName ) ){
return;
}
#endif
/* Establish a read-lock on the table at the shared-cache level.
** Open a read-only cursor on the table. Also allocate a cursor number
** to use for scanning indexes (iIdxCur). No index cursor is opened at
** this time though. */
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
iTabCur = iTab++;
iIdxCur = iTab++;
pParse->nTab = MAX(pParse->nTab, iTab);
sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int nCol; /* Number of columns in pIdx. "N" */
**
** end_of_scan:
*/
/* Make sure there are enough memory cells allocated to accommodate
** the regPrev array and a trailing rowid (the rowid slot is required
** when building a record to insert into the sample column of
** the sqlite_stat4 table. */
pParse->nMem = MAX(pParse->nMem, regPrev+nColTest);
/* Open a read-only cursor on the index being analyzed. */
assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb);
sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
VdbeComment((v, "%s", pIdx->zName));
/* Invoke the stat_init() function. The arguments are:
**
** (1) the number of columns in the index including the rowid
** (or for a WITHOUT ROWID table, the number of PK columns),
** (2) the number of columns in the key without the rowid/pk
/* Finally, jump back to the beginning of the executable code. */
sqlite3VdbeAddOp2(v, OP_Goto, 0, 1);
}
}
/* Get the VDBE program ready for execution
*/
if( v && ALWAYS(pParse->nErr==0) && !db->mallocFailed ){
assert( pParse->iCacheLevel==0 ); /* Disables and re-enables match */
/* A minimum of one cursor is required if autoincrement is used
* See ticket [a696379c1f08866] */
if( pParse->pAinc!=0 && pParse->nTab==0 ) pParse->nTab = 1;
sqlite3VdbeMakeReady(v, pParse);
pParse->rc = SQLITE_DONE;
pParse->colNamesSet = 0;
}else{
pParse->rc = SQLITE_ERROR;
}
pParse->nTab = 0;
pParse->nMem = 0;
zName = sqlite3DbStrNDup(db, (char*)pName->z, pName->n);
sqlite3Dequote(zName);
}else{
zName = 0;
}
return zName;
}
/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *p, int iDb){
Vdbe *v = sqlite3GetVdbe(p);
sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, MASTER_ROOT, iDb, 5);
if( p->nTab==0 ){
p->nTab = 1;
}
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
/*
** The Table structure pTable is really a VIEW. Fill in the names of
** the columns of the view in the pTable structure. Return the number
** of errors. If an error is seen leave an error message in pParse->zErrMsg.
*/
SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
Table *pSelTab; /* A fake table from which we get the result set */
Select *pSel; /* Copy of the SELECT that implements the view */
int nErr = 0; /* Number of errors encountered */
int n; /* Temporarily holds the number of cursors assigned */
sqlite3 *db = pParse->db; /* Database connection for malloc errors */
sqlite3_xauth xAuth; /* Saved xAuth pointer */
assert( pTable );
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( sqlite3VtabCallConnect(pParse, pTable) ){
return SQLITE_ERROR;
}
if( IsVirtual(pTable) ) return 0;
** SELECT * FROM temp.ex1;
*/
if( pTable->nCol<0 ){
sqlite3ErrorMsg(pParse, "view %s is circularly defined", pTable->zName);
return 1;
}
assert( pTable->nCol>=0 );
/* If we get this far, it means we need to compute the table names.
** Note that the call to sqlite3ResultSetOfSelect() will expand any
** "*" elements in the results set of the view and will assign cursors
** to the elements of the FROM clause. But we do not want these changes
** to be permanent. So the computation is done on a copy of the SELECT
** statement that defines the view.
*/
assert( pTable->pSelect );
pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
if( pSel ){
u8 enableLookaside = db->lookaside.bEnabled;
n = pParse->nTab;
sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
** content of an index in response to a REINDEX command.
**
** if memRootPage is not negative, it means that the index is newly
** created. The register specified by memRootPage contains the
** root page number of the index. If memRootPage is negative, then
** the index already exists and must be cleared before being refilled and
** the root page number of the index is taken from pIndex->tnum.
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
Table *pTab = pIndex->pTable; /* The table that is indexed */
int iTab = pParse->nTab++; /* Btree cursor used for pTab */
int iIdx = pParse->nTab++; /* Btree cursor used for pIndex */
int iSorter; /* Cursor opened by OpenSorter (if in use) */
int addr1; /* Address of top of loop */
int addr2; /* Address to jump to for next iteration */
int tnum; /* Root page of index */
int iPartIdxLabel; /* Jump to this label to skip a row */
Vdbe *v; /* Generate code into this virtual machine */
KeyInfo *pKey; /* KeyInfo for index */
int regRecord; /* Register holding assembled index record */
sqlite3 *db = pParse->db; /* The database connection */
int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
v = sqlite3GetVdbe(pParse);
if( v==0 ) return;
if( memRootPage>=0 ){
tnum = memRootPage;
}else{
tnum = pIndex->tnum;
}
pKey = sqlite3KeyInfoOfIndex(pParse, pIndex);
/* Open the sorter cursor if we are to use one. */
iSorter = pParse->nTab++;
sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, pIndex->nKeyCol, (char*)
sqlite3KeyInfoRef(pKey), P4_KEYINFO);
/* Open the table. Loop through all rows of the table, inserting index
** records into the sorter. */
sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0); VdbeCoverage(v);
regRecord = sqlite3GetTempReg(pParse);
SrcList *pTabList, /* The table from which we should delete things */
Expr *pWhere /* The WHERE clause. May be null */
){
Vdbe *v; /* The virtual database engine */
Table *pTab; /* The table from which records will be deleted */
const char *zDb; /* Name of database holding pTab */
int i; /* Loop counter */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Index *pIdx; /* For looping over indices of the table */
int iTabCur; /* Cursor number for the table */
int iDataCur = 0; /* VDBE cursor for the canonical data source */
int iIdxCur = 0; /* Cursor number of the first index */
int nIdx; /* Number of indices */
sqlite3 *db; /* Main database structure */
AuthContext sContext; /* Authorization context */
NameContext sNC; /* Name context to resolve expressions in */
int iDb; /* Database number */
int memCnt = -1; /* Memory cell used for change counting */
int rcauth; /* Value returned by authorization callback */
int okOnePass; /* True for one-pass algorithm without the FIFO */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
u8 *aToOpen = 0; /* Open cursor iTabCur+j if aToOpen[j] is true */
Index *pPk; /* The PRIMARY KEY index on the table */
int iPk = 0; /* First of nPk registers holding PRIMARY KEY value */
i16 nPk = 1; /* Number of columns in the PRIMARY KEY */
int iKey; /* Memory cell holding key of row to be deleted */
i16 nKey; /* Number of memory cells in the row key */
int iEphCur = 0; /* Ephemeral table holding all primary key values */
int iRowSet = 0; /* Register for rowset of rows to delete */
int addrBypass = 0; /* Address of jump over the delete logic */
int addrLoop = 0; /* Top of the delete loop */
int addrDelete = 0; /* Jump directly to the delete logic */
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb<db->nDb );
zDb = db->aDb[iDb].zName;
rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
if( rcauth==SQLITE_DENY ){
goto delete_from_cleanup;
}
assert(!isView || pTrigger);
/* Assign cursor numbers to the table and all its indices.
*/
assert( pTabList->nSrc==1 );
iTabCur = pTabList->a[0].iCursor = pParse->nTab++;
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
pParse->nTab++;
}
/* Start the view context
*/
if( isView ){
/* End of the WHERE loop */
sqlite3WhereEnd(pWInfo);
if( okOnePass ){
/* Bypass the delete logic below if the WHERE loop found zero rows */
addrBypass = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBypass);
sqlite3VdbeJumpHere(v, addrDelete);
}
/* Unless this is a view, open cursors for the table we are
** deleting from and all its indices. If this is a view, then the
** only effect this statement has is to fire the INSTEAD OF
** triggers.
*/
if( !isView ){
testcase( IsVirtual(pTab) );
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
&iDataCur, &iIdxCur);
assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
if( okOnePass ){
sqlite3VdbeResolveLabel(v, addrBypass);
}else if( pPk ){
sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addrLoop);
}else{
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrLoop);
sqlite3VdbeJumpHere(v, addrLoop);
}
/* Close the cursors open on the table and its indexes. */
if( !isView && !IsVirtual(pTab) ){
if( !pPk ) sqlite3VdbeAddOp1(v, OP_Close, iDataCur);
for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqlite3VdbeAddOp1(v, OP_Close, iIdxCur + i);
}
}
} /* End non-truncate path */
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
#undef pTrigger
#endif
/*
** This routine generates VDBE code that causes a single row of a
** single table to be deleted. Both the original table entry and
** all indices are removed.
**
** Preconditions:
**
** 1. iDataCur is an open cursor on the btree that is the canonical data
** store for the table. (This will be either the table itself,
** in the case of a rowid table, or the PRIMARY KEY index in the case
** of a WITHOUT ROWID table.)
**
** 2. Read/write cursors for all indices of pTab must be open as
** cursor number iIdxCur+i for the i-th index.
**
** 3. The primary key for the row to be deleted must be stored in a
** sequence of nPk memory cells starting at iPk. If nPk==0 that means
** that a search record formed from OP_MakeRecord is contained in the
** single memory location iPk.
*/
SQLITE_PRIVATE void sqlite3GenerateRowDelete(
Parse *pParse, /* Parsing context */
Table *pTab, /* Table containing the row to be deleted */
Trigger *pTrigger, /* List of triggers to (potentially) fire */
int iDataCur, /* Cursor from which column data is extracted */
int iIdxCur, /* First index cursor */
int iPk, /* First memory cell containing the PRIMARY KEY */
i16 nPk, /* Number of PRIMARY KEY memory cells */
u8 count, /* If non-zero, increment the row change counter */
u8 onconf, /* Default ON CONFLICT policy for triggers */
u8 bNoSeek /* iDataCur is already pointing to the row to delete */
){
Vdbe *v = pParse->pVdbe; /* Vdbe */
int iOld = 0; /* First register in OLD.* array */
int iLabel; /* Label resolved to end of generated code */
u8 opSeek; /* Seek opcode */
/* Vdbe is guaranteed to have been allocated by this stage. */
assert( v );
VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",
iDataCur, iIdxCur, iPk, (int)nPk));
/* Seek cursor iCur to the row to delete. If this row no longer exists
** (this can happen if a trigger program has already deleted it), do
** not attempt to delete it or fire any DELETE triggers. */
iLabel = sqlite3VdbeMakeLabel(v);
opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
if( !bNoSeek ){
sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
VdbeCoverageIf(v, opSeek==OP_NotExists);
VdbeCoverageIf(v, opSeek==OP_NotFound);
}
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+iCol+1);
}
}
/* Invoke BEFORE DELETE trigger programs. */
addrStart = sqlite3VdbeCurrentAddr(v);
sqlite3CodeRowTrigger(pParse, pTrigger,
TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel
);
/* If any BEFORE triggers were coded, then seek the cursor to the
** row to be deleted again. It may be that the BEFORE triggers moved
** the cursor or of already deleted the row that the cursor was
** pointing to.
*/
if( addrStart<sqlite3VdbeCurrentAddr(v) ){
sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
VdbeCoverageIf(v, opSeek==OP_NotExists);
VdbeCoverageIf(v, opSeek==OP_NotFound);
}
/* Do FK processing. This call checks that any FK constraints that
** refer to this table (i.e. constraints attached to other tables)
sqlite3VdbeResolveLabel(v, iLabel);
VdbeModuleComment((v, "END: GenRowDel()"));
}
/*
** This routine generates VDBE code that causes the deletion of all
** index entries associated with a single row of a single table, pTab
**
** Preconditions:
**
** 1. A read/write cursor "iDataCur" must be open on the canonical storage
** btree for the table pTab. (This will be either the table itself
** for rowid tables or to the primary key index for WITHOUT ROWID
** tables.)
**
** 2. Read/write cursors for all indices of pTab must be open as
** cursor number iIdxCur+i for the i-th index. (The pTab->pIndex
** index is the 0-th index.)
**
** 3. The "iDataCur" cursor must be already be positioned on the row
** that is to be deleted.
*/
SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(
Parse *pParse, /* Parsing and code generating context */
Table *pTab, /* Table containing the row to be deleted */
int iDataCur, /* Cursor of table holding data. */
int iIdxCur, /* First index cursor */
int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
){
int i; /* Index loop counter */
int r1 = -1; /* Register holding an index key */
int iPartIdxLabel; /* Jump destination for skipping partial index entries */
Index *pIdx; /* Current index */
Index *pPrior = 0; /* Prior index */
Vdbe *v; /* The prepared statement under construction */
Index *pPk; /* PRIMARY KEY index, or NULL for rowid tables */
sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
pPrior = pIdx;
}
}
/*
** Generate code that will assemble an index key and stores it in register
** regOut. The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
** the entry that needs indexing. If pTab is a WITHOUT ROWID table, then
** iCur must be the cursor of the PRIMARY KEY index.
**
** Return a register number which is the first in a block of
** registers that holds the elements of the index key. The
** block of registers has already been deallocated by the time
** this routine returns.
**
** If *piPartIdxLabel is not NULL, fill it in with a label and jump
** to that label if pIdx is a partial index that should be skipped.
** The label should be resolved using sqlite3ResolvePartIdxLabel().
** A partial index should be skipped if its WHERE clause evaluates
}else{
pExpr->iTable = regBase;
pExpr->affinity = SQLITE_AFF_INTEGER;
}
}
return pExpr;
}
/*
** Return an Expr object that refers to column iCol of table pTab which
** has cursor iCur.
*/
static Expr *exprTableColumn(
sqlite3 *db, /* The database connection */
Table *pTab, /* The table whose column is desired */
int iCursor, /* The open cursor on the table */
i16 iCol /* The column that is wanted */
){
Expr *pExpr = sqlite3Expr(db, TK_COLUMN, 0);
if( pExpr ){
pExpr->pTab = pTab;
pExpr->iTable = iCursor;
pExpr->iColumn = iCol;
}
return pExpr;
}
if( db->xAuth ){
int rcauth;
char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);
bIgnore = (rcauth==SQLITE_IGNORE);
}
#endif
}
/* Take a shared-cache advisory read-lock on the parent table. Allocate
** a cursor to use to search the unique index on the parent key columns
** in the parent table. */
sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);
pParse->nTab++;
if( regOld!=0 ){
/* A row is being removed from the child table. Search for the parent.
** If the parent does not exist, removing the child row resolves an
** outstanding foreign key constraint violation. */
fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, bIgnore);
}
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
*/
/*
** Generate code that will
**
** (1) acquire a lock for table pTab then
** (2) open pTab as cursor iCur.
**
** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index
** for that table that is actually opened.
*/
SQLITE_PRIVATE void sqlite3OpenTable(
Parse *pParse, /* Generate code into this VDBE */
int iCur, /* The cursor number of the table */
int iDb, /* The database index in sqlite3.aDb[] */
Table *pTab, /* The table to be opened */
int opcode /* OP_OpenRead or OP_OpenWrite */
){
Vdbe *v;
assert( !IsVirtual(pTab) );
v = sqlite3GetVdbe(pParse);
assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
sqlite3TableLock(pParse, iDb, pTab->tnum,
(opcode==OP_OpenWrite)?1:0, pTab->zName);
** The pList parameter holds EXPRLIST in the first form of the INSERT
** statement above, and pSelect is NULL. For the second form, pList is
** NULL and pSelect is a pointer to the select statement used to generate
** data for the insert.
**
** The code generated follows one of four templates. For a simple
** insert with data coming from a VALUES clause, the code executes
** once straight down through. Pseudo-code follows (we call this
** the "1st template"):
**
** open write cursor to <table> and its indices
** put VALUES clause expressions into registers
** write the resulting record into <table>
** cleanup
**
** The three remaining templates assume the statement is of the form
**
** INSERT INTO <table> SELECT ...
**
** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
** in other words if the SELECT pulls all columns from a single table
** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
** if <table2> and <table1> are distinct tables but have identical
** schemas, including all the same indices, then a special optimization
** is invoked that copies raw records from <table2> over to <table1>.
** See the xferOptimization() function for the implementation of this
** template. This is the 2nd template.
**
** open a write cursor to <table>
** open read cursor on <table2>
** transfer all records in <table2> over to <table>
** close cursors
** foreach index on <table>
** open a write cursor on the <table> index
** open a read cursor on the corresponding <table2> index
** transfer all records from the read to the write cursors
** close cursors
** end foreach
**
** The 3rd template is for when the second template does not apply
** and the SELECT clause does not read from <table> at any time.
** The generated code follows this template:
**
** X <- A
** goto B
** A: setup for the SELECT
** loop over the rows in the SELECT
** load values into registers R..R+n
** yield X
** end loop
** cleanup after the SELECT
** end-coroutine X
** B: open write cursor to <table> and its indices
** C: yield X, at EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: cleanup
**
** The 4th template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT. In the third form,
** we have to use an intermediate table to store the results of
** the select. The template is like this:
** loop over the tables in the SELECT
** load value into register R..R+n
** yield X
** end loop
** cleanup after the SELECT
** end co-routine R
** B: open temp table
** L: yield X, at EOF goto M
** insert row from R..R+n into temp table
** goto L
** M: open write cursor to <table> and its indices
** rewind temp table
** C: loop over rows of intermediate table
** transfer values form intermediate table into <table>
** end loop
** D: cleanup
*/
SQLITE_PRIVATE void sqlite3Insert(
Parse *pParse, /* Parser context */
SrcList *pTabList, /* Name of table into which we are inserting */
Select *pSelect, /* A SELECT statement to use as the data source */
){
sqlite3 *db; /* The main database structure */
Table *pTab; /* The table to insert into. aka TABLE */
char *zTab; /* Name of the table into which we are inserting */
const char *zDb; /* Name of the database holding this table */
int i, j, idx; /* Loop counters */
Vdbe *v; /* Generate code into this virtual machine */
Index *pIdx; /* For looping over indices of the table */
int nColumn; /* Number of columns in the data */
int nHidden = 0; /* Number of hidden columns if TABLE is virtual */
int iDataCur = 0; /* VDBE cursor that is the main data repository */
int iIdxCur = 0; /* First index cursor */
int ipkColumn = -1; /* Column that is the INTEGER PRIMARY KEY */
int endOfLoop; /* Label for the end of the insertion loop */
int srcTab = 0; /* Data comes from this temporary cursor if >=0 */
int addrInsTop = 0; /* Jump to label "D" */
int addrCont = 0; /* Top of insert loop. Label "C" in templates 3 and 4 */
SelectDest dest; /* Destination for SELECT on rhs of INSERT */
int iDb; /* Index of database holding TABLE */
Db *pDb; /* The database containing table being inserted into */
u8 useTempTable = 0; /* Store SELECT results in intermediate table */
u8 appendFlag = 0; /* True if the insert is likely to be an append */
u8 withoutRowid; /* 0 for normal table. 1 for WITHOUT ROWID table */
u8 bIdListInOrder = 1; /* True if IDLIST is in table order */
ExprList *pList = 0; /* List of VALUES() to be inserted */
** that the table is a WITHOUT ROWID table and has no rowid. On an INSERT,
** pkChng will only be true if the INSERT statement provides an integer
** value for either the rowid column or its INTEGER PRIMARY KEY alias.
**
** The code generated by this routine will store new index entries into
** registers identified by aRegIdx[]. No index entry is created for
** indices where aRegIdx[i]==0. The order of indices in aRegIdx[] is
** the same as the order of indices on the linked list of indices
** at pTab->pIndex.
**
** The caller must have already opened writeable cursors on the main
** table and all applicable indices (that is to say, all indices for which
** aRegIdx[] is not zero). iDataCur is the cursor for the main table when
** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
** index when operating on a WITHOUT ROWID table. iIdxCur is the cursor
** for the first index in the pTab->pIndex list. Cursors for other indices
** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
**
** This routine also generates code to check constraints. NOT NULL,
** CHECK, and UNIQUE constraints are all checked. If a constraint fails,
** then the appropriate action is performed. There are five possible
** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
**
** Constraint type Action What Happens
** --------------- ---------- ----------------------------------------
**
** Which action to take is determined by the overrideError parameter.
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used. Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
*/
SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
Parse *pParse, /* The parser context */
Table *pTab, /* The table being inserted or updated */
int *aRegIdx, /* Use register aRegIdx[i] for index i. 0 for unused */
int iDataCur, /* Canonical data cursor (main table or PK index) */
int iIdxCur, /* First index cursor */
int regNewData, /* First register in a range holding values to insert */
int regOldData, /* Previous content. 0 for INSERTs */
u8 pkChng, /* Non-zero if the rowid or PRIMARY KEY changed */
u8 overrideError, /* Override onError to this if not OE_Default */
int ignoreDest, /* Jump to this label on an OE_Ignore resolution */
int *pbMayReplace /* OUT: Set to true if constraint may cause a replace */
){
Vdbe *v; /* VDBE under constrution */
Index *pIdx; /* Pointer to one of the indices */
Index *pPk = 0; /* The PRIMARY KEY index */
** A consecutive range of registers starting at regNewData contains the
** rowid and the content to be inserted.
**
** The arguments to this routine should be the same as the first six
** arguments to sqlite3GenerateConstraintChecks.
*/
SQLITE_PRIVATE void sqlite3CompleteInsertion(
Parse *pParse, /* The parser context */
Table *pTab, /* the table into which we are inserting */
int iDataCur, /* Cursor of the canonical data source */
int iIdxCur, /* First index cursor */
int regNewData, /* Range of content */
int *aRegIdx, /* Register used by each index. 0 for unused indices */
int isUpdate, /* True for UPDATE, False for INSERT */
int appendBias, /* True if this is likely to be an append */
int useSeekResult /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
){
Vdbe *v; /* Prepared statements under construction */
Index *pIdx; /* An index being inserted or updated */
u8 pik_flags; /* flag values passed to the btree insert */
int regData; /* Content registers (after the rowid) */
pik_flags |= OPFLAG_USESEEKRESULT;
}
sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, regRec, regNewData);
if( !pParse->nested ){
sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
}
sqlite3VdbeChangeP5(v, pik_flags);
}
/*
** Allocate cursors for the pTab table and all its indices and generate
** code to open and initialized those cursors.
**
** The cursor for the object that contains the complete data (normally
** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
** ROWID table) is returned in *piDataCur. The first index cursor is
** returned in *piIdxCur. The number of indices is returned.
**
** Use iBase as the first cursor (either the *piDataCur for rowid tables
** or the first index for WITHOUT ROWID tables) if it is non-negative.
** If iBase is negative, then allocate the next available cursor.
**
** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
** pTab->pIndex list.
**
** If pTab is a virtual table, then this routine is a no-op and the
** *piDataCur and *piIdxCur values are left uninitialized.
*/
SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
Parse *pParse, /* Parsing context */
Table *pTab, /* Table to be opened */
int op, /* OP_OpenRead or OP_OpenWrite */
int iBase, /* Use this for the table cursor, if there is one */
u8 *aToOpen, /* If not NULL: boolean for each table and index */
int *piDataCur, /* Write the database source cursor number here */
int *piIdxCur /* Write the first index cursor number here */
){
int i;
int iDb;
int iDataCur;
Index *pIdx;
Vdbe *v;
assert( op==OP_OpenRead || op==OP_OpenWrite );
if( IsVirtual(pTab) ){
/* This routine is a no-op for virtual tables. Leave the output
sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
if( initData.rc ){
rc = initData.rc;
goto error_out;
}
pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
if( ALWAYS(pTab) ){
pTab->tabFlags |= TF_Readonly;
}
/* Create a cursor to hold the database open
*/
pDb = &db->aDb[iDb];
if( pDb->pBt==0 ){
if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){
DbSetProperty(db, 1, DB_SchemaLoaded);
}
return SQLITE_OK;
}
/* If there is not already a read-only (or read-write) transaction opened
case SRT_Fifo:
case SRT_DistFifo:
case SRT_Table:
case SRT_EphemTab: {
int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);
testcase( eDest==SRT_Table );
testcase( eDest==SRT_EphemTab );
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);
#ifndef SQLITE_OMIT_CTE
if( eDest==SRT_DistFifo ){
/* If the destination is DistFifo, then cursor (iParm+1) is open
** on an ephemeral index. If the current row is already present
** in the index, do not write it to the output. If not, add the
** current row to the index and proceed with writing it to the
** output table as well. */
int addr = sqlite3VdbeCurrentAddr(v) + 4;
sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0); VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1);
assert( pSort==0 );
}
#endif
sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
}else{
sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
}
break;
}
#ifndef SQLITE_OMIT_CTE
/* Write the results into a priority queue that is order according to
** pDest->pOrderBy (in pSO). pDest->iSDParm (in iParm) is the cursor for an
** index with pSO->nExpr+2 columns. Build a key using pSO for the first
** pSO->nExpr columns, then make sure all keys are unique by adding a
** final OP_Sequence column. The last column is the record as a blob.
*/
case SRT_DistQueue:
case SRT_Queue: {
int nKey;
int r1, r2, r3;
int addrTest = 0;
ExprList *pSO;
pSO = pDest->pOrderBy;
assert( pSO );
nKey = pSO->nExpr;
r1 = sqlite3GetTempReg(pParse);
r2 = sqlite3GetTempRange(pParse, nKey+2);
r3 = r2+nKey+1;
if( eDest==SRT_DistQueue ){
/* If the destination is DistQueue, then cursor (iParm+1) is open
** on a second ephemeral index that holds all values every previously
** added to the queue. */
addrTest = sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, 0,
regResult, nResultCol);
VdbeCoverage(v);
}
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r3);
if( eDest==SRT_DistQueue ){
sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r3);
sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
int addrContinue = sqlite3VdbeMakeLabel(v); /* Jump here for next cycle */
int addr;
int addrOnce = 0;
int iTab;
ExprList *pOrderBy = pSort->pOrderBy;
int eDest = pDest->eDest;
int iParm = pDest->iSDParm;
int regRow;
int regRowid;
int nKey;
int iSortTab; /* Sorter cursor to read from */
int nSortData; /* Trailing values to read from sorter */
int i;
int bSeq; /* True if sorter record includes seq. no. */
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
struct ExprList_item *aOutEx = p->pEList->a;
#endif
if( pSort->labelBkOut ){
sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBreak);
addrBreak = sqlite3VdbeMakeLabel(v);
computeLimitRegisters(pParse, p, addrBreak);
pLimit = p->pLimit;
pOffset = p->pOffset;
regLimit = p->iLimit;
regOffset = p->iOffset;
p->pLimit = p->pOffset = 0;
p->iLimit = p->iOffset = 0;
pOrderBy = p->pOrderBy;
/* Locate the cursor number of the Current table */
for(i=0; ALWAYS(i<pSrc->nSrc); i++){
if( pSrc->a[i].isRecursive ){
iCurrent = pSrc->a[i].iCursor;
break;
}
}
/* Allocate cursors numbers for Queue and Distinct. The cursor number for
** the Distinct table must be exactly one greater than Queue in order
** for the SRT_DistFifo and SRT_DistQueue destinations to work. */
iQueue = pParse->nTab++;
if( p->op==TK_UNION ){
eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo;
iDistinct = pParse->nTab++;
}else{
eDest = pOrderBy ? SRT_Queue : SRT_Fifo;
}
sqlite3SelectDestInit(&destQueue, eDest, iQueue);
/* Allocate cursors for Current, Queue, and Distinct. */
regCurrent = ++pParse->nMem;
sqlite3VdbeAddOp3(v, OP_OpenPseudo, iCurrent, regCurrent, nCol);
if( pOrderBy ){
KeyInfo *pKeyInfo = multiSelectOrderByKeyInfo(pParse, p, 1);
sqlite3VdbeAddOp4(v, OP_OpenEphemeral, iQueue, pOrderBy->nExpr+2, 0,
(char*)pKeyInfo, P4_KEYINFO);
destQueue.pOrderBy = pOrderBy;
}else{
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iQueue, nCol);
}
}
/* Reassembly the compound query so that it will be freed correctly
** by the calling function */
if( p->pPrior ){
sqlite3SelectDelete(db, p->pPrior);
}
p->pPrior = pPrior;
pPrior->pNext = p;
/*** TBD: Insert subroutine calls to close cursors on incomplete
**** subqueries ****/
explainComposite(pParse, p->op, iSub1, iSub2, 0);
return SQLITE_OK;
}
#endif
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/* Forward Declarations */
static void substExprList(sqlite3*, ExprList*, int, ExprList*);
static void substSelect(sqlite3*, Select *, int, ExprList *);
/*
** Scan through the expression pExpr. Replace every reference to
** a column in table number iTable with a copy of the iColumn-th
** entry in pEList. (But leave references to the ROWID column
** unchanged.)
**
** This routine is part of the flattening procedure. A subquery
** whose result set is defined by pEList appears as entry in the
** FROM clause of a SELECT such that the VDBE cursor assigned to that
** FORM clause entry is iTable. This routine make the necessary
** changes to pExpr so that it refers directly to the source table
** of the subquery rather the result set of the subquery.
*/
static Expr *substExpr(
sqlite3 *db, /* Report malloc errors to this connection */
Expr *pExpr, /* Expr in which substitution occurs */
int iTable, /* Table to be substituted */
ExprList *pEList /* Substitute expressions */
){
int isAgg, /* True if outer SELECT uses aggregate functions */
int subqueryIsAgg /* True if the subquery uses aggregate functions */
){
const char *zSavedAuthContext = pParse->zAuthContext;
Select *pParent;
Select *pSub; /* The inner query or "subquery" */
Select *pSub1; /* Pointer to the rightmost select in sub-query */
SrcList *pSrc; /* The FROM clause of the outer query */
SrcList *pSubSrc; /* The FROM clause of the subquery */
ExprList *pList; /* The result set of the outer query */
int iParent; /* VDBE cursor number of the pSub result set temp table */
int i; /* Loop counter */
Expr *pWhere; /* The WHERE clause */
struct SrcList_item *pSubitem; /* The subquery */
sqlite3 *db = pParse->db;
/* Check to see if flattening is permitted. Return 0 if not.
*/
assert( p!=0 );
assert( p->pPrior==0 ); /* Unable to flatten compound queries */
if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
pSubitem->pTab = 0;
}
/* The following loop runs once for each term in a compound-subquery
** flattening (as described above). If we are doing a different kind
** of flattening - a flattening other than a compound-subquery flattening -
** then this loop only runs once.
**
** This loop moves all of the FROM elements of the subquery into the
** the FROM clause of the outer query. Before doing this, remember
** the cursor number for the original outer query FROM element in
** iParent. The iParent cursor will never be used. Subsequent code
** will scan expressions looking for iParent references and replace
** those references with expressions that resolve to the subquery FROM
** elements we are now copying in.
*/
for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
int nSubSrc;
u8 jointype = 0;
pSubSrc = pSub->pSrc; /* FROM clause of subquery */
nSubSrc = pSubSrc->nSrc; /* Number of terms in subquery FROM clause */
pSrc = pParent->pSrc; /* FROM clause of the outer query */
}
}
#else
#define selectPopWith 0
#endif
/*
** This routine is a Walker callback for "expanding" a SELECT statement.
** "Expanding" means to do the following:
**
** (1) Make sure VDBE cursor numbers have been assigned to every
** element of the FROM clause.
**
** (2) Fill in the pTabList->a[].pTab fields in the SrcList that
** defines FROM clause. When views appear in the FROM clause,
** fill pTabList->a[].pSelect with a copy of the SELECT statement
** that implements the view. A copy is made of the view's SELECT
** statement so that we can freely modify or delete that statement
** without worrying about messing up the persistent representation
** of the view.
**
}
if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
return WRC_Prune;
}
pTabList = p->pSrc;
pEList = p->pEList;
if( pWalker->xSelectCallback2==selectPopWith ){
sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);
}
/* Make sure cursor numbers have been assigned to all entries in
** the FROM clause of the SELECT statement.
*/
sqlite3SrcListAssignCursors(pParse, pTabList);
/* Look up every table named in the FROM clause of the select. If
** an entry of the FROM clause is a subquery instead of a table or view,
** then create a transient table structure to describe the subquery.
*/
for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
Table *pTab;
for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
ExprList *pList = pF->pExpr->x.pList;
assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
sqlite3VdbeAddOp4(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0, 0,
(void*)pF->pFunc, P4_FUNCDEF);
}
}
/*
** Update the accumulator memory cells for an aggregate based on
** the current cursor position.
*/
static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
Vdbe *v = pParse->pVdbe;
int i;
int regHit = 0;
int addrHitTest = 0;
struct AggInfo_func *pF;
struct AggInfo_col *pC;
pAggInfo->directMode = 1;
&& (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
){
pBest = pIdx;
}
}
if( pBest ){
iRoot = pBest->tnum;
pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pBest);
}
/* Open a read-only cursor, execute the OP_Count, close the cursor. */
sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, iRoot, iDb, 1);
if( pKeyInfo ){
sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
}
sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
sqlite3VdbeAddOp1(v, OP_Close, iCsr);
explainSimpleCount(pParse, pTab, pBest);
}else
#endif /* SQLITE_OMIT_BTREECOUNT */
{
int onError /* How to handle constraint errors */
){
int i, j; /* Loop counters */
Table *pTab; /* The table to be updated */
int addrTop = 0; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */
int nIdx; /* Number of indices that need updating */
int iBaseCur; /* Base cursor number */
int iDataCur; /* Cursor for the canonical data btree */
int iIdxCur; /* Cursor for the first index */
sqlite3 *db; /* The database structure */
int *aRegIdx = 0; /* One register assigned to each index to be updated */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
u8 *aToOpen; /* 1 for tables and indices to be opened */
u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */
u8 chngRowid; /* Rowid changed in a normal table */
int labelContinue; /* Jump here to continue next step of UPDATE loop */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True when updating a view (INSTEAD OF trigger) */
Trigger *pTrigger; /* List of triggers on pTab, if required */
int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
#endif
int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */
int iEph = 0; /* Ephemeral table holding all primary key values */
int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
/* Register Allocations */
int regRowCount = 0; /* A count of rows changed */
int regOldRowid; /* The old rowid */
int regNewRowid; /* The new rowid */
int regNew; /* Content of the NEW.* table in triggers */
int regOld = 0; /* Content of OLD.* table in triggers */
int regRowSet = 0; /* Rowset of rows to be updated */
int regKey = 0; /* composite PRIMARY KEY value */
# define isView 0
#endif
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
goto update_cleanup;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++;
iIdxCur = iDataCur+1;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
if( IsPrimaryKeyIndex(pIdx) && pPk!=0 ){
iDataCur = pParse->nTab;
pTabList->a[0].iCursor = iDataCur;
}
** its elements.
**
** The WhereInfo object contains a single instance of this object for
** each term in the FROM clause (which is to say, for each of the
** nested loops as implemented). The order of WhereLevel objects determines
** the loop nested order, with WhereInfo.a[0] being the outer loop and
** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
*/
struct WhereLevel {
int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
int iTabCur; /* The VDBE cursor used to access the table */
int iIdxCur; /* The VDBE cursor used to access pIdx */
int addrBrk; /* Jump here to break out of the loop */
int addrNxt; /* Jump here to start the next IN combination */
int addrSkip; /* Jump here for next iteration of skip-scan */
int addrCont; /* Jump here to continue with the next loop cycle */
int addrFirst; /* First instruction of interior of the loop */
int addrBody; /* Beginning of the body of this loop */
u8 iFrom; /* Which entry in the FROM clause */
u8 op, p3, p5; /* Opcode, P3 & P5 of the opcode that ends the loop */
int p1, p2; /* Operands of the opcode used to ends the loop */
union { /* Information that depends on pWLoop->wsFlags */
struct {
int nIn; /* Number of entries in aInLoop[] */
struct InLoop {
int iCur; /* The VDBE cursor used by this IN operator */
int addrInTop; /* Top of the IN loop */
u8 eEndLoopOp; /* IN Loop terminator. OP_Next or OP_Prev */
} *aInLoop; /* Information about each nested IN operator */
} in; /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
Index *pCovidx; /* Possible covering index for WHERE_MULTI_OR */
} u;
struct WhereLoop *pWLoop; /* The selected WhereLoop object */
Bitmask notReady; /* FROM entries not usable at this level */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
int addrVisit; /* Address at which row is visited */
** The following identity holds:
**
** WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm
**
** When a term is of the form:
**
** X <op> <expr>
**
** where X is a column name and <op> is one of certain operators,
** then WhereTerm.leftCursor and WhereTerm.u.leftColumn record the
** cursor number and column number for X. WhereTerm.eOperator records
** the <op> using a bitmask encoding defined by WO_xxx below. The
** use of a bitmask encoding for the operator allows us to search
** quickly for terms that match any of several different operators.
**
** A WhereTerm might also be two or more subterms connected by OR:
**
** (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....
**
** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR
** and the WhereTerm.u.pOrInfo field points to auxiliary information that
** is collected about the OR clause.
**
** If a term in the WHERE clause does not match either of the two previous
** categories, then eOperator==0. The WhereTerm.pExpr field is still set
** to the original subexpression content and wtFlags is set up appropriately
** but no other fields in the WhereTerm object are meaningful.
**
** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers,
** but they do so indirectly. A single WhereMaskSet structure translates
** cursor number into bits and the translated bit is stored in the prereq
** fields. The translation is used in order to maximize the number of
** bits that will fit in a Bitmask. The VDBE cursor numbers might be
** spread out over the non-negative integers. For example, the cursor
** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45. The WhereMaskSet
** translates these sparse cursor numbers into consecutive integers
** beginning with 0 in order to make the best possible use of the available
** bits in the Bitmask. So, in the example above, the cursor numbers
** would be mapped into integers 0 through 7.
**
** The number of terms in a join is limited by the number of bits
** in prereqRight and prereqAll. The default is 64 bits, hence SQLite
** is only able to process joins with 64 or fewer tables.
*/
struct WhereTerm {
Expr *pExpr; /* Pointer to the subexpression that is this term */
int iParent; /* Disable pWC->a[iParent] when this term disabled */
int leftCursor; /* Cursor number of X in "X <op> <expr>" */
/*
** A WhereTerm with eOperator==WO_AND has its u.pAndInfo pointer set to
** a dynamically allocated instance of the following structure.
*/
struct WhereAndInfo {
WhereClause wc; /* The subexpression broken out */
};
/*
** An instance of the following structure keeps track of a mapping
** between VDBE cursor numbers and bits of the bitmasks in WhereTerm.
**
** The VDBE cursor numbers are small integers contained in
** SrcList_item.iCursor and Expr.iTable fields. For any given WHERE
** clause, the cursor numbers might not begin with 0 and they might
** contain gaps in the numbering sequence. But we want to make maximum
** use of the bits in our bitmasks. This structure provides a mapping
** from the sparse cursor numbers into consecutive integers beginning
** with 0.
**
** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
** corresponds VDBE cursor number B. The A-th bit of a bitmask is 1<<A.
**
** For example, if the WHERE clause expression used these VDBE
** cursors: 4, 5, 8, 29, 57, 73. Then the WhereMaskSet structure
** would map those cursor numbers into bits 0 through 5.
**
** Note that the mapping is not necessarily ordered. In the example
** above, the mapping might go like this: 4->3, 5->1, 8->2, 29->0,
** 57->5, 73->4. Or one of 719 other combinations might be used. It
** does not really matter. What is important is that sparse cursor
** numbers all get mapped into bit numbers that begin with 0 and contain
** no gaps.
*/
struct WhereMaskSet {
int n; /* Number of assigned cursor values */
int ix[BMS]; /* Cursor assigned to each bit */
};
/*
** This object is a convenience wrapper holding all information needed
** to construct WhereLoop objects for a particular query.
*/
struct WhereLoopBuilder {
WhereInfo *pWInfo; /* Information about this WHERE */
WhereClause *pWC; /* WHERE clause terms */
i8 nOBSat; /* Number of ORDER BY terms satisfied by indices */
u8 sorted; /* True if really sorted (not just grouped) */
u8 okOnePass; /* Ok to use one-pass algorithm for UPDATE/DELETE */
u8 untestedTerms; /* Not all WHERE terms resolved by outer loop */
u8 eDistinct; /* One of the WHERE_DISTINCT_* values below */
u8 nLevel; /* Number of nested loop */
int iTop; /* The very beginning of the WHERE loop */
int iContinue; /* Jump here to continue with next record */
int iBreak; /* Jump here to break out of the loop */
int savedNQueryLoop; /* pParse->nQueryLoop outside the WHERE loop */
int aiCurOnePass[2]; /* OP_OpenWrite cursors for the ONEPASS opt */
WhereMaskSet sMaskSet; /* Map cursor numbers to bitmasks */
WhereClause sWC; /* Decomposition of the WHERE clause */
WhereLevel a[1]; /* Information about each nest loop in WHERE */
};
/*
** Bitmasks for the operators on WhereTerm objects. These are all
** operators that are of interest to the query planner. An
** OR-ed combination of these values can be used when searching for
** particular WhereTerms within a WhereClause.
*/
SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
return pWInfo->iBreak;
}
/*
** Return TRUE if an UPDATE or DELETE statement can operate directly on
** the rowids returned by a WHERE clause. Return FALSE if doing an
** UPDATE or DELETE might change subsequent WHERE clause results.
**
** If the ONEPASS optimization is used (if this routine returns true)
** then also write the indices of open cursors used by ONEPASS
** into aiCur[0] and aiCur[1]. iaCur[0] gets the cursor of the data
** table and iaCur[1] gets the cursor used by an auxiliary index.
** Either value may be -1, indicating that cursor is not used.
** Any cursors returned will have been opened for writing.
**
** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
** unable to use the ONEPASS optimization.
*/
SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
return pWInfo->okOnePass;
}
/*
whereSplit(pWC, pExpr->pRight, op);
}
}
/*
** Initialize a WhereMaskSet object
*/
#define initMaskSet(P) (P)->n=0
/*
** Return the bitmask for the given cursor number. Return 0 if
** iCursor is not in the set.
*/
static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
int i;
assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
for(i=0; i<pMaskSet->n; i++){
if( pMaskSet->ix[i]==iCursor ){
return MASKBIT(i);
}
}
return 0;
}
/*
** Create a new mask for cursor iCursor.
**
** There is one cursor per table in the FROM clause. The number of
** tables in the FROM clause is limited by a test early in the
** sqlite3WhereBegin() routine. So we know that the pMaskSet->ix[]
** array will never overflow.
*/
static void createMask(WhereMaskSet *pMaskSet, int iCursor){
assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
pMaskSet->ix[pMaskSet->n++] = iCursor;
}
/*
assert( op!=TK_GE || c==WO_GE );
return c;
}
/*
** Advance to the next WhereTerm that matches according to the criteria
** established when the pScan object was initialized by whereScanInit().
** Return NULL if there are no more matching WhereTerms.
*/
static WhereTerm *whereScanNext(WhereScan *pScan){
int iCur; /* The cursor on the LHS of the term */
int iColumn; /* The column on the LHS of the term. -1 for IPK */
Expr *pX; /* An expression being tested */
WhereClause *pWC; /* Shorthand for pScan->pWC */
WhereTerm *pTerm; /* The term being tested */
int k = pScan->k; /* Where to start scanning */
while( pScan->iEquiv<=pScan->nEquiv ){
iCur = pScan->aEquiv[pScan->iEquiv-2];
iColumn = pScan->aEquiv[pScan->iEquiv-1];
while( (pWC = pScan->pWC)!=0 ){
/*
** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
** where X is a reference to the iColumn of table iCur and <op> is one of
** the WO_xx operator codes specified by the op parameter.
** Return a pointer to the term. Return 0 if not found.
**
** The term returned might by Y=<expr> if there is another constraint in
** the WHERE clause that specifies that X=Y. Any such constraints will be
** identified by the WO_EQUIV bit in the pTerm->eOperator field. The
** aEquiv[] array holds X and all its equivalents, with each SQL variable
** taking up two slots in aEquiv[]. The first slot is for the cursor number
** and the second is for the column number. There are 22 slots in aEquiv[]
** so that means we can look for X plus up to 10 other equivalent values.
** Hence a search for X will return <expr> if X=A1 and A1=A2 and A2=A3
** and ... and A9=A10 and A10=<expr>.
**
** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"
** then try for the one with no dependencies on <expr> - in other words where
** <expr> is a constant expression of some kind. Only return entries of
** the form "X <op> Y" where Y is a column in another table if no terms of
** the form "X <op> <const-expr>" exist. If no terms with a constant RHS
**
** then create a new virtual term like this:
**
** x IN (expr1,expr2,expr3)
**
** CASE 2:
**
** If all subterms are indexable by a single table T, then set
**
** WhereTerm.eOperator = WO_OR
** WhereTerm.u.pOrInfo->indexable |= the cursor number for table T
**
** A subterm is "indexable" if it is of the form
** "T.C <op> <expr>" where C is any column of table T and
** <op> is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".
** A subterm is also indexable if it is an AND of two or more
** subsubterms at least one of which is indexable. Indexable AND
** subterms have their eOperator set to WO_AND and they have
** u.pAndInfo set to a dynamically allocated WhereAndTerm object.
**
** From another point of view, "indexable" means that the subterm could
** might be possible to form an IN operator with either table1.column
** or table2.column as the LHS if either is common to every term of
** the OR clause.
**
** Note that terms of the form "table.column1=table.column2" (the
** same table on both sizes of the ==) cannot be optimized.
*/
if( chngToIN ){
int okToChngToIN = 0; /* True if the conversion to IN is valid */
int iColumn = -1; /* Column index on lhs of IN operator */
int iCursor = -1; /* Table cursor common to all terms */
int j = 0; /* Loop counter */
/* Search for a table and column that appears on one side or the
** other of the == operator in every subterm. That table and column
** will be recorded in iCursor and iColumn. There might not be any
** such table and column. Set okToChngToIN if an appropriate table
** and column is found but leave okToChngToIN false if not found.
*/
for(j=0; j<2 && !okToChngToIN; j++){
pOrTerm = pOrWc->a;
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** Generate code to construct the Index object for an automatic index
** and to set up the WhereLevel object pLevel so that the code generator
** makes use of the automatic index.
*/
static void constructAutomaticIndex(
Parse *pParse, /* The parsing context */
WhereClause *pWC, /* The WHERE clause */
struct SrcList_item *pSrc, /* The FROM clause term to get the next index */
Bitmask notReady, /* Mask of cursors that are not available */
WhereLevel *pLevel /* Write new index here */
){
int nKeyCol; /* Number of columns in the constructed index */
WhereTerm *pTerm; /* A single term of the WHERE clause */
WhereTerm *pWCEnd; /* End of pWC->a[] */
Index *pIdx; /* Object describing the transient index */
Vdbe *v; /* Prepared statement under construction */
int addrInit; /* Address of the initialization bypass jump */
Table *pTable; /* The table being indexed */
int addrTop; /* Top of the index fill loop */
/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
static Bitmask codeOneLoopStart(
WhereInfo *pWInfo, /* Complete information about the WHERE clause */
int iLevel, /* Which level of pWInfo->a[] should be coded */
Bitmask notReady /* Which tables are currently available */
){
int j, k; /* Loop counters */
int iCur; /* The VDBE cursor for the table */
int addrNxt; /* Where to jump to continue with the next IN case */
int omitTable; /* True if we use the index only */
int bRev; /* True if we need to scan in reverse order */
WhereLevel *pLevel; /* The where level to be coded */
WhereLoop *pLoop; /* The WhereLoop object being coded */
WhereClause *pWC; /* Decomposition of the entire WHERE clause */
WhereTerm *pTerm; /* A WHERE clause term */
Parse *pParse; /* Parsing context */
sqlite3 *db; /* Database connection */
Vdbe *v; /* The prepared stmt under constructions */
};
u16 nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */
int regBase; /* Base register holding constraint values */
WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
int startEq; /* True if range start uses ==, >= or <= */
int endEq; /* True if range end uses ==, >= or <= */
int start_constraints; /* Start of range is constrained */
int nConstraint; /* Number of constraint terms */
Index *pIdx; /* The index we will be using */
int iIdxCur; /* The VDBE cursor for the index */
int nExtraReg = 0; /* Number of extra registers needed */
int op; /* Instruction opcode */
char *zStartAff; /* Affinity for start of range constraint */
char cEndAff = 0; /* Affinity for end of range constraint */
u8 bSeekPastNull = 0; /* True to seek past initial nulls */
u8 bStopAtNull = 0; /* Add condition to terminate at NULLs */
pIdx = pLoop->u.btree.pIndex;
iIdxCur = pLevel->iIdxCur;
assert( nEq>=pLoop->nSkip );
}
testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
start_constraints = pRangeStart || nEq>0;
/* Seek the index cursor to the start of the range. */
nConstraint = nEq;
if( pRangeStart ){
Expr *pRight = pRangeStart->pExpr->pRight;
sqlite3ExprCode(pParse, pRight, regBase+nEq);
if( (pRangeStart->wtFlags & TERM_VNULL)==0
&& sqlite3ExprCanBeNull(pRight)
){
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
VdbeCoverage(v);
}
}else if( bStopAtNull ){
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
endEq = 0;
nConstraint++;
}
sqlite3DbFree(db, zStartAff);
/* Top of the loop body */
pLevel->p2 = sqlite3VdbeCurrentAddr(v);
/* Check if the index cursor is past the end of the range. */
if( nConstraint ){
op = aEndOp[bRev*2 + endEq];
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
}
/* Seek the table cursor, if required */
disableTerm(pLevel, pRangeStart);
disableTerm(pLevel, pRangeEnd);
if( omitTable ){
/* pIdx is a covering index. No need to access the main table. */
}else if( HasRowid(pIdx->pTable) ){
iRowidReg = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg); /* Deferred seek */
}else if( iCur!=iIdxCur ){
/* Initialize the rowset register to contain NULL. An SQL NULL is
** equivalent to an empty rowset. Or, create an ephemeral index
** capable of holding primary keys in the case of a WITHOUT ROWID.
**
** Also initialize regReturn to contain the address of the instruction
** immediately following the OP_Return at the bottom of the loop. This
** is required in a few obscure LEFT JOIN cases where control jumps
** over the top of the loop into the body of it. In this case the
** correct response for the end-of-loop code (the OP_Return) is to
** fall through to the next instruction, just as an OP_Next does if
** called on an uninitialized cursor.
*/
if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
if( HasRowid(pTab) ){
regRowset = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
}else{
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
regRowset = pParse->nTab++;
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
if( j1 ) sqlite3VdbeJumpHere(v, j1);
/* The pSubWInfo->untestedTerms flag means that this OR term
** contained one or more AND term from a notReady table. The
** terms from the notReady table could not be tested and will
** need to be tested later.
*/
if( pSubWInfo->untestedTerms ) untestedTerms = 1;
/* If all of the OR-connected terms are optimized using the same
** index, and the index is opened using the same cursor number
** by each call to sqlite3WhereBegin() made by this loop, it may
** be possible to use that index as a covering index.
**
** If the call to sqlite3WhereBegin() above resulted in a scan that
** uses an index, and this is either the first OR-connected term
** processed or the index is the same as that used by all previous
** terms, set pCov to the candidate covering index. Otherwise, set
** pCov to NULL to indicate that no candidate covering index will
** be available.
*/
{
/* Case 6: There is no usable index. We must do a complete
** scan of the entire table.
*/
static const u8 aStep[] = { OP_Next, OP_Prev };
static const u8 aStart[] = { OP_Rewind, OP_Last };
assert( bRev==0 || bRev==1 );
if( pTabItem->isRecursive ){
/* Tables marked isRecursive have only a single row that is stored in
** a pseudo-cursor. No need to Rewind or Next such cursors. */
pLevel->op = OP_Noop;
}else{
pLevel->op = aStep[bRev];
pLevel->p1 = iCur;
pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
VdbeCoverageIf(v, bRev==0);
VdbeCoverageIf(v, bRev!=0);
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
}
}
*/
static void whereTermPrint(WhereTerm *pTerm, int iTerm){
if( pTerm==0 ){
sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);
}else{
char zType[4];
memcpy(zType, "...", 4);
if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
if( pTerm->eOperator & WO_EQUIV ) zType[1] = 'E';
if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
sqlite3DebugPrintf("TERM-%-3d %p %s cursor=%-3d prob=%-3d op=0x%03x\n",
iTerm, pTerm, zType, pTerm->leftCursor, pTerm->truthProb,
pTerm->eOperator);
sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
}
}
#endif
#ifdef WHERETRACE_ENABLED
/*
** Print a WhereLoop object for debugging purposes
** end \ Code generated
** end |-- by sqlite3WhereEnd()
** end /
**
** Note that the loops might not be nested in the order in which they
** appear in the FROM clause if a different order is better able to make
** use of indices. Note also that when the IN operator appears in
** the WHERE clause, it might result in additional nested loops for
** scanning through all values on the right-hand side of the IN.
**
** There are Btree cursors associated with each table. t1 uses cursor
** number pTabList->a[0].iCursor. t2 uses the cursor pTabList->a[1].iCursor.
** And so forth. This routine generates code to open those VDBE cursors
** and sqlite3WhereEnd() generates the code to close them.
**
** The code that sqlite3WhereBegin() generates leaves the cursors named
** in pTabList pointing at their appropriate entries. The [...] code
** can use OP_Column and OP_Rowid opcodes on these cursors to extract
** data from the various tables of the loop.
**
** If the WHERE clause is empty, the foreach loops must each scan their
** entire tables. Thus a three-way join is an O(N^3) operation. But if
** the tables have indices and there are terms in the WHERE clause that
** refer to those indices, a complete table scan can be avoided and the
** code will run much faster. Most of the work of this routine is checking
** to see if there are indices that can be used to speed up the loop.
**
** Terms of the WHERE clause are also used to limit which rows actually
** An outer join of tables t1 and t2 is conceptally coded as follows:
**
** foreach row1 in t1 do
** flag = 0
** foreach row2 in t2 do
** start:
** ...
** flag = 1
** end
** if flag==0 then
** move the row2 cursor to a null row
** goto start
** fi
** end
**
** ORDER BY CLAUSE PROCESSING
**
** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
** if there is one. If there is no ORDER BY clause or if this routine
** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
**
** The iIdxCur parameter is the cursor number of an index. If
** WHERE_ONETABLE_ONLY is set, iIdxCur is the cursor number of an index
** to use for OR clause processing. The WHERE clause should use this
** specific cursor. If WHERE_ONEPASS_DESIRED is set, then iIdxCur is
** the first cursor in an array of cursors for all indices. iIdxCur should
** be used to compute the appropriate cursor depending on which index is
** used.
*/
SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* FROM clause: A list of all tables to be scanned */
Expr *pWhere, /* The WHERE clause */
ExprList *pOrderBy, /* An ORDER BY (or GROUP BY) clause, or NULL */
ExprList *pResultSet, /* Result set of the query */
u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */
int iIdxCur /* If WHERE_ONETABLE_ONLY is set, index cursor number */
){
int nByteWInfo; /* Num. bytes allocated for WhereInfo struct */
int nTabList; /* Number of elements in pTabList */
WhereInfo *pWInfo; /* Will become the return value of this function */
Vdbe *v = pParse->pVdbe; /* The virtual database engine */
Bitmask notReady; /* Cursors that are not yet positioned */
WhereLoopBuilder sWLB; /* The WhereLoop builder */
WhereMaskSet *pMaskSet; /* The expression mask set */
WhereLevel *pLevel; /* A single level in pWInfo->a[] */
WhereLoop *pLoop; /* Pointer to a single WhereLoop object */
*/
testcase( pTabList->nSrc==BMS );
if( pTabList->nSrc>BMS ){
sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
return 0;
}
/* This function normally generates a nested loop for all tables in
** pTabList. But if the WHERE_ONETABLE_ONLY flag is set, then we should
** only generate code for the first table in pTabList and assume that
** any cursors associated with subsequent tables are uninitialized.
*/
nTabList = (wctrlFlags & WHERE_ONETABLE_ONLY) ? 1 : pTabList->nSrc;
/* Allocate and initialize the WhereInfo structure that will become the
** return value. A single allocation is used to store the WhereInfo
** struct, the contents of WhereInfo.a[], the WhereClause structure
** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
** field (type Bitmask) it must be aligned on an 8-byte boundary on
** some architectures. Hence the ROUND8() below.
*/
*/
if( nTabList==0 ){
if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;
if( wctrlFlags & WHERE_WANT_DISTINCT ){
pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
}
}
/* Assign a bit from the bitmask to every term in the FROM clause.
**
** When assigning bitmask values to FROM clause cursors, it must be
** the case that if X is the bitmask for the N-th FROM clause term then
** the bitmask for all FROM clause terms to the left of the N-th term
** is (X-1). An expression from the ON clause of a LEFT JOIN can use
** its Expr.iRightJoinTable value to find the bitmask of the right table
** of the join. Subtracting one from the right table bitmask gives a
** bitmask for all tables to the left of the join. Knowing the bitmask
** for all tables to the left of a left join is important. Ticket #3015.
**
** Note that bitmasks are created for all pTabList->nSrc tables in
** pTabList, not just the first nTabList tables. nTabList is normally
pOp->p3 = 0;
}else if( pOp->opcode==OP_Rowid ){
pOp->opcode = OP_Null;
pOp->p1 = 0;
pOp->p3 = 0;
}
}
continue;
}
/* Close all of the cursors that were opened by sqlite3WhereBegin.
** Except, do not close cursors that will be reused by the OR optimization
** (WHERE_OMIT_OPEN_CLOSE). And do not close the OP_OpenWrite cursors
** created for the ONEPASS optimization.
*/
if( (pTab->tabFlags & TF_Ephemeral)==0
&& pTab->pSelect==0
&& (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
){
int ws = pLoop->wsFlags;
if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
}
sqlite3_mutex_free(db->mutex);
assert( db->lookaside.nOut==0 ); /* Fails on a lookaside memory leak */
if( db->lookaside.bMalloced ){
sqlite3_free(db->lookaside.pStart);
}
sqlite3_free(db);
}
/*
** Rollback all database files. If tripCode is not SQLITE_OK, then
** any write cursors are invalidated ("tripped" - as in "tripping a circuit
** breaker") and made to return tripCode if there are any further
** attempts to use that cursor. Read cursors remain open and valid
** but are "saved" in case the table pages are moved around.
*/
SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db, int tripCode){
int i;
int inTrans = 0;
int schemaChange;
assert( sqlite3_mutex_held(db->mutex) );
sqlite3BeginBenignMalloc();
/* Obtain all b-tree mutexes before making any calls to BtreeRollback().
** Defines the interface to tokenizers used by fulltext-search. There
** are three basic components:
**
** sqlite3_tokenizer_module is a singleton defining the tokenizer
** interface functions. This is essentially the class structure for
** tokenizers.
**
** sqlite3_tokenizer is used to define a particular tokenizer, perhaps
** including customization information defined at creation time.
**
** sqlite3_tokenizer_cursor is generated by a tokenizer to generate
** tokens from a particular input.
*/
#ifndef _FTS3_TOKENIZER_H_
#define _FTS3_TOKENIZER_H_
/* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.
** If tokenizers are to be allowed to call sqlite3_*() functions, then
** we will need a way to register the API consistently.
*/
** functions that make up an implementation.
**
** When an fts3 table is created, it passes any arguments passed to
** the tokenizer clause of the CREATE VIRTUAL TABLE statement to the
** sqlite3_tokenizer_module.xCreate() function of the requested tokenizer
** implementation. The xCreate() function in turn returns an
** sqlite3_tokenizer structure representing the specific tokenizer to
** be used for the fts3 table (customized by the tokenizer clause arguments).
**
** To tokenize an input buffer, the sqlite3_tokenizer_module.xOpen()
** method is called. It returns an sqlite3_tokenizer_cursor object
** that may be used to tokenize a specific input buffer based on
** the tokenization rules supplied by a specific sqlite3_tokenizer
** object.
*/
typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
typedef struct sqlite3_tokenizer sqlite3_tokenizer;
typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
struct sqlite3_tokenizer_module {
/*
** Structure version. Should always be set to 0 or 1.
*/
int iVersion;
/*
** Create a new tokenizer. The values in the argv[] array are the
sqlite3_tokenizer **ppTokenizer /* OUT: Created tokenizer */
);
/*
** Destroy an existing tokenizer. The fts3 module calls this method
** exactly once for each successful call to xCreate().
*/
int (*xDestroy)(sqlite3_tokenizer *pTokenizer);
/*
** Create a tokenizer cursor to tokenize an input buffer. The caller
** is responsible for ensuring that the input buffer remains valid
** until the cursor is closed (using the xClose() method).
*/
int (*xOpen)(
sqlite3_tokenizer *pTokenizer, /* Tokenizer object */
const char *pInput, int nBytes, /* Input buffer */
sqlite3_tokenizer_cursor **ppCursor /* OUT: Created tokenizer cursor */
);
/*
** Destroy an existing tokenizer cursor. The fts3 module calls this
** method exactly once for each successful call to xOpen().
*/
int (*xClose)(sqlite3_tokenizer_cursor *pCursor);
/*
** Retrieve the next token from the tokenizer cursor pCursor. This
** method should either return SQLITE_OK and set the values of the
** "OUT" variables identified below, or SQLITE_DONE to indicate that
** the end of the buffer has been reached, or an SQLite error code.
**
** *ppToken should be set to point at a buffer containing the
** normalized version of the token (i.e. after any case-folding and/or
** stemming has been performed). *pnBytes should be set to the length
** of this buffer in bytes. The input text that generated the token is
** identified by the byte offsets returned in *piStartOffset and
** *piEndOffset. *piStartOffset should be set to the index of the first
**
** The buffer *ppToken is set to point at is managed by the tokenizer
** implementation. It is only required to be valid until the next call
** to xNext() or xClose().
*/
/* TODO(shess) current implementation requires pInput to be
** nul-terminated. This should either be fixed, or pInput/nBytes
** should be converted to zInput.
*/
int (*xNext)(
sqlite3_tokenizer_cursor *pCursor, /* Tokenizer cursor */
const char **ppToken, int *pnBytes, /* OUT: Normalized text for token */
int *piStartOffset, /* OUT: Byte offset of token in input buffer */
int *piEndOffset, /* OUT: Byte offset of end of token in input buffer */
int *piPosition /* OUT: Number of tokens returned before this one */
);
/***********************************************************************
** Methods below this point are only available if iVersion>=1.
*/
/*
** Configure the language id of a tokenizer cursor.
*/
int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);
};
struct sqlite3_tokenizer {
const sqlite3_tokenizer_module *pModule; /* The module for this tokenizer */
/* Tokenizer implementations will typically add additional fields */
};
struct sqlite3_tokenizer_cursor {
sqlite3_tokenizer *pTokenizer; /* Tokenizer for this cursor. */
/* Tokenizer implementations will typically add additional fields */
};
int fts3_global_term_cnt(int iTerm, int iCol);
int fts3_term_cnt(int iTerm, int iCol);
#endif /* _FTS3_TOKENIZER_H_ */
/************** End of fts3_tokenizer.h **************************************/
#ifdef SQLITE_TEST
/* True to disable the incremental doclist optimization. This is controled
** by special insert command 'test-no-incr-doclist'. */
int bNoIncrDoclist;
#endif
};
/*
** When the core wants to read from the virtual table, it creates a
** virtual table cursor (an instance of the following structure) using
** the xOpen method. Cursors are destroyed using the xClose method.
*/
struct Fts3Cursor {
sqlite3_vtab_cursor base; /* Base class used by SQLite core */
i16 eSearch; /* Search strategy (see below) */
u8 isEof; /* True if at End Of Results */
u8 isRequireSeek; /* True if must seek pStmt to %_content row */
sqlite3_stmt *pStmt; /* Prepared statement in use by the cursor */
Fts3Expr *pExpr; /* Parsed MATCH query string */
int iLangid; /* Language being queried for */
int nPhrase; /* Number of matchable phrases in query */
Fts3DeferredToken *pDeferred; /* Deferred search tokens, if any */
sqlite3_int64 iPrevId; /* Previous id read from aDoclist */
char *pNextId; /* Pointer into the body of aDoclist */
char *aDoclist; /* List of docids for full-text queries */
int nDoclist; /* Size of buffer at aDoclist */
u8 bDesc; /* True to sort in descending order */
int eEvalmode; /* An FTS3_EVAL_XX constant */
SQLITE_PRIVATE int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
char **, int, int, int, const char *, int, Fts3Expr **, char **
);
SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
SQLITE_PRIVATE int sqlite3Fts3InitTerm(sqlite3 *db);
#endif
SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,
sqlite3_tokenizer_cursor **
);
/* fts3_aux.c */
SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db);
SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *);
SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(
Fts3Table*, Fts3MultiSegReader*, int, const char*, int);
SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(
}
}
assert( p->pSegments==0 );
return SQLITE_OK;
}
/*
** Implementation of xOpen method.
*/
static int fts3OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
sqlite3_vtab_cursor *pCsr; /* Allocated cursor */
UNUSED_PARAMETER(pVTab);
/* Allocate a buffer large enough for an Fts3Cursor structure. If the
** allocation succeeds, zero it and return SQLITE_OK. Otherwise,
** if the allocation fails, return SQLITE_NOMEM.
*/
*ppCsr = pCsr = (sqlite3_vtab_cursor *)sqlite3_malloc(sizeof(Fts3Cursor));
if( !pCsr ){
return SQLITE_NOMEM;
}
memset(pCsr, 0, sizeof(Fts3Cursor));
return SQLITE_OK;
}
/*
** Close the cursor. For additional information see the documentation
** on the xClose method of the virtual table interface.
*/
static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
sqlite3_finalize(pCsr->pStmt);
sqlite3Fts3ExprFree(pCsr->pExpr);
sqlite3Fts3FreeDeferredTokens(pCsr);
sqlite3_free(pCsr->aDoclist);
sqlite3_free(pCsr->aMatchinfo);
assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
sqlite3_free(pCsr);
return SQLITE_OK;
}
finished:
rc2 = sqlite3_reset(pStmt);
if( rc==SQLITE_DONE ) rc = rc2;
return rc;
}
/*
** Set up a cursor object for iterating through a full-text index or a
** single level therein.
*/
SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(
Fts3Table *p, /* FTS3 table handle */
int iLangid, /* Language-id to search */
int iIndex, /* Index to search (from 0 to p->nIndex-1) */
int iLevel, /* Level of segments to scan */
const char *zTerm, /* Term to query for */
int nTerm, /* Size of zTerm in bytes */
int isPrefix, /* True for a prefix search */
** a pointer to the new Fts3MultiSegReader to *ppSegcsr. Otherwise, return
** an SQLite error code.
**
** It is the responsibility of the caller to free this object by eventually
** passing it to fts3SegReaderCursorFree()
**
** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
** Output parameter *ppSegcsr is set to 0 if an error occurs.
*/
static int fts3TermSegReaderCursor(
Fts3Cursor *pCsr, /* Virtual table cursor handle */
const char *zTerm, /* Term to query for */
int nTerm, /* Size of zTerm in bytes */
int isPrefix, /* True for a prefix search */
Fts3MultiSegReader **ppSegcsr /* OUT: Allocated seg-reader cursor */
){
Fts3MultiSegReader *pSegcsr; /* Object to allocate and return */
int rc = SQLITE_NOMEM; /* Return code */
pSegcsr = sqlite3_malloc(sizeof(Fts3MultiSegReader));
if( pSegcsr ){
int i;
int bFound = 0; /* True once an index has been found */
Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
** prefix) from the database.
*/
static int fts3TermSelect(
Fts3Table *p, /* Virtual table handle */
Fts3PhraseToken *pTok, /* Token to query for */
int iColumn, /* Column to query (or -ve for all columns) */
int *pnOut, /* OUT: Size of buffer at *ppOut */
char **ppOut /* OUT: Malloced result buffer */
){
int rc; /* Return code */
Fts3MultiSegReader *pSegcsr; /* Seg-reader cursor for this term */
TermSelect tsc; /* Object for pair-wise doclist merging */
Fts3SegFilter filter; /* Segment term filter configuration */
pSegcsr = pTok->pSegcsr;
memset(&tsc, 0, sizeof(TermSelect));
filter.flags = FTS3_SEGMENT_IGNORE_EMPTY | FTS3_SEGMENT_REQUIRE_POS
| (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)
| (pTok->bFirst ? FTS3_SEGMENT_FIRST : 0)
| (iColumn<p->nColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);
nDoc++;
while( (*p++)&0x80 ); /* Skip docid varint */
fts3PoslistCopy(0, &p); /* Skip over position list */
}
}
return nDoc;
}
/*
** Advance the cursor to the next row in the %_content table that
** matches the search criteria. For a MATCH search, this will be
** the next row that matches. For a full-table scan, this will be
** simply the next row in the %_content table. For a docid lookup,
** this routine simply sets the EOF flag.
**
** Return SQLITE_OK if nothing goes wrong. SQLITE_OK is returned
** even if we reach end-of-file. The fts3EofMethod() will be called
** subsequently to determine whether or not an EOF was hit.
*/
static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){
int rc;
Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
if( pCsr->eSearch==FTS3_DOCID_SEARCH || pCsr->eSearch==FTS3_FULLSCAN_SEARCH ){
if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){
pCsr->isEof = 1;
rc = sqlite3_reset(pCsr->pStmt);
}else{
pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);
rc = SQLITE_OK;
}
**
** If idxNum==FTS3_DOCID_SEARCH then do a docid lookup for a single entry
** in the %_content table.
**
** If idxNum>=FTS3_FULLTEXT_SEARCH then use the full text index. The
** column on the left-hand side of the MATCH operator is column
** number idxNum-FTS3_FULLTEXT_SEARCH, 0 indexed. argv[0] is the right-hand
** side of the MATCH operator.
*/
static int fts3FilterMethod(
sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */
int idxNum, /* Strategy index */
const char *idxStr, /* Unused */
int nVal, /* Number of elements in apVal */
sqlite3_value **apVal /* Arguments for the indexing scheme */
){
int rc = SQLITE_OK;
char *zSql; /* SQL statement used to access %_content */
int eSearch;
Fts3Table *p = (Fts3Table *)pCursor->pVtab;
Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
assert( p->pSegments==0 );
/* Collect arguments into local variables */
iIdx = 0;
if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];
if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];
if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
assert( iIdx==nVal );
/* In case the cursor has been used before, clear it now. */
sqlite3_finalize(pCsr->pStmt);
sqlite3_free(pCsr->aDoclist);
sqlite3_free(pCsr->aMatchinfo);
sqlite3Fts3ExprFree(pCsr->pExpr);
memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));
/* Set the lower and upper bounds on docids to return */
pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);
if( idxStr ){
pCsr->bDesc = (idxStr[0]=='D');
}else{
pCsr->bDesc = p->bDescIdx;
}
return rc;
}
rc = fts3EvalStart(pCsr);
sqlite3Fts3SegmentsClose(p);
if( rc!=SQLITE_OK ) return rc;
pCsr->pNextId = pCsr->aDoclist;
pCsr->iPrevId = 0;
}
/* Compile a SELECT statement for this cursor. For a full-table-scan, the
** statement loops through all rows of the %_content table. For a
** full-text query or docid lookup, the statement retrieves a single
** row by docid.
*/
if( eSearch==FTS3_FULLSCAN_SEARCH ){
zSql = sqlite3_mprintf(
"SELECT %s ORDER BY rowid %s",
p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
);
if( zSql ){
}
if( rc!=SQLITE_OK ) return rc;
return fts3NextMethod(pCursor);
}
/*
** This is the xEof method of the virtual table. SQLite calls this
** routine to find out if it has reached the end of a result set.
*/
static int fts3EofMethod(sqlite3_vtab_cursor *pCursor){
return ((Fts3Cursor *)pCursor)->isEof;
}
/*
** This is the xRowid method. The SQLite core calls this routine to
** retrieve the rowid for the current row of the result set. fts3
** exposes %_content.docid as the rowid for the virtual table. The
** rowid should be written to *pRowid.
*/
static int fts3RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
*pRowid = pCsr->iPrevId;
return SQLITE_OK;
}
/*
** This is the xColumn method, called by SQLite to request a value from
** the row that the supplied cursor currently points to.
**
** If:
**
** (iCol < p->nColumn) -> The value of the iCol'th user column.
** (iCol == p->nColumn) -> Magic column with the same name as the table.
** (iCol == p->nColumn+1) -> Docid column
** (iCol == p->nColumn+2) -> Langid column
*/
static int fts3ColumnMethod(
sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */
sqlite3_context *pCtx, /* Context for sqlite3_result_xxx() calls */
int iCol /* Index of column to read value from */
){
int rc = SQLITE_OK; /* Return Code */
Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
Fts3Table *p = (Fts3Table *)pCursor->pVtab;
/* The column value supplied by SQLite must be in range. */
assert( iCol>=0 && iCol<=p->nColumn+2 );
if( iCol==p->nColumn+1 ){
/* This call is a request for the "docid" column. Since "docid" is an
** alias for "rowid", use the xRowid() method to obtain the value.
*/
sqlite3_result_int64(pCtx, pCsr->iPrevId);
}else if( iCol==p->nColumn ){
/* The extra column whose name is the same as the table.
** Return a blob which is a pointer to the cursor. */
sqlite3_result_blob(pCtx, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);
}else if( iCol==p->nColumn+2 && pCsr->pExpr ){
sqlite3_result_int64(pCtx, pCsr->iLangid);
}else{
/* The requested column is either a user column (one that contains
** indexed data), or the language-id column. */
rc = fts3CursorSeek(0, pCsr);
if( rc==SQLITE_OK ){
if( iCol==p->nColumn+2 ){
** If the value passed as the third argument is a blob of size
** sizeof(Fts3Cursor*), then the blob contents are copied to the
** output variable *ppCsr and SQLITE_OK is returned. Otherwise, an error
** message is written to context pContext and SQLITE_ERROR returned. The
** string passed via zFunc is used as part of the error message.
*/
static int fts3FunctionArg(
sqlite3_context *pContext, /* SQL function call context */
const char *zFunc, /* Function name */
sqlite3_value *pVal, /* argv[0] passed to function */
Fts3Cursor **ppCsr /* OUT: Store cursor handle here */
){
Fts3Cursor *pRet;
if( sqlite3_value_type(pVal)!=SQLITE_BLOB
|| sqlite3_value_bytes(pVal)!=sizeof(Fts3Cursor *)
){
char *zErr = sqlite3_mprintf("illegal first argument to %s", zFunc);
sqlite3_result_error(pContext, zErr, -1);
sqlite3_free(zErr);
return SQLITE_ERROR;
}
sqlite3Fts3HashClear(pHash);
sqlite3_free(pHash);
}
return rc;
}
/*
** Allocate an Fts3MultiSegReader for each token in the expression headed
** by pExpr.
**
** An Fts3SegReader object is a cursor that can seek or scan a range of
** entries within a single segment b-tree. An Fts3MultiSegReader uses multiple
** Fts3SegReader objects internally to provide an interface to seek or scan
** within the union of all segments of a b-tree. Hence the name.
**
** If the allocated Fts3MultiSegReader just seeks to a single entry in a
** segment b-tree (if the term is not a prefix or it is a prefix for which
** there exists prefix b-tree of the right length) then it may be traversed
** and merged incrementally. Otherwise, it has to be merged into an in-memory
** doclist and then traversed.
*/
static void fts3EvalAllocateReaders(
Fts3Cursor *pCsr, /* FTS cursor handle */
Fts3Expr *pExpr, /* Allocate readers for this expression */
int *pnToken, /* OUT: Total number of tokens in phrase. */
int *pnOr, /* OUT: Total number of OR nodes in expr. */
int *pRc /* IN/OUT: Error code */
){
if( pExpr && SQLITE_OK==*pRc ){
if( pExpr->eType==FTSQUERY_PHRASE ){
int i;
int nToken = pExpr->pPhrase->nToken;
*pnToken += nToken;
** Assuming no error occurs or has occurred, It returns non-zero if the
** expression passed as the second argument matches the row that pCsr
** currently points to, or zero if it does not.
**
** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
** If an error occurs during execution of this function, *pRc is set to
** the appropriate SQLite error code. In this case the returned value is
** undefined.
*/
static int fts3EvalTestExpr(
Fts3Cursor *pCsr, /* FTS cursor handle */
Fts3Expr *pExpr, /* Expr to test. May or may not be root. */
int *pRc /* IN/OUT: Error code */
){
int bHit = 1; /* Return value */
if( *pRc==SQLITE_OK ){
switch( pExpr->eType ){
case FTSQUERY_NEAR:
case FTSQUERY_AND:
bHit = (
fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)
break;
}
}
}
return bHit;
}
/*
** This function is called as the second part of each xNext operation when
** iterating through the results of a full-text query. At this point the
** cursor points to a row that matches the query expression, with the
** following caveats:
**
** * Up until this point, "NEAR" operators in the expression have been
** treated as "AND".
**
** * Deferred tokens have not yet been considered.
**
** If *pRc is not SQLITE_OK when this function is called, it immediately
** returns 0. Otherwise, it tests whether or not after considering NEAR
** operators and deferred tokens the current row is still a match for the
}
assert( sqlite3_data_count(pCsr->pStmt)==0 );
fts3EvalNextRow(pCsr, pExpr, &rc);
pCsr->isEof = pExpr->bEof;
pCsr->isRequireSeek = 1;
pCsr->isMatchinfoNeeded = 1;
pCsr->iPrevId = pExpr->iDocid;
}while( pCsr->isEof==0 && fts3EvalTestDeferredAndNear(pCsr, &rc) );
}
/* Check if the cursor is past the end of the docid range specified
** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag. */
if( rc==SQLITE_OK && (
(pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
|| (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)
)){
pCsr->isEof = 1;
}
return rc;
}
pExpr->bEof = 0;
pExpr->bStart = 0;
fts3EvalRestart(pCsr, pExpr->pLeft, pRc);
fts3EvalRestart(pCsr, pExpr->pRight, pRc);
}
}
/*
** After allocating the Fts3Expr.aMI[] array for each phrase in the
** expression rooted at pExpr, the cursor iterates through all rows matched
** by pExpr, calling this function for each row. This function increments
** the values in Fts3Expr.aMI[] according to the position-list currently
** found in Fts3Expr.pPhrase->doclist.pList for each of the phrase
** expression nodes.
*/
static void fts3EvalUpdateCounts(Fts3Expr *pExpr){
if( pExpr ){
Fts3Phrase *pPhrase = pExpr->pPhrase;
if( pPhrase && pPhrase->doclist.pList ){
int iCol = 0;
** column of each row of the table.
**
** * If a phrase contains some deferred tokens (and some non-deferred
** tokens), count the potential occurrence identified by considering
** the non-deferred tokens instead of actual phrase occurrences.
**
** * If the phrase is part of a NEAR expression, then only phrase instances
** that meet the NEAR constraint are included in the counts.
*/
SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(
Fts3Cursor *pCsr, /* FTS cursor handle */
Fts3Expr *pExpr, /* Phrase expression */
u32 *aiOut /* Array to write results into (see above) */
){
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
int rc = SQLITE_OK;
int iCol;
if( pExpr->bDeferred && pExpr->pParent->eType!=FTSQUERY_NEAR ){
assert( pCsr->nDoc>0 );
for(iCol=0; iCol<pTab->nColumn; iCol++){
** compression and is terminated by either an 0x01 or 0x00 byte. For example,
** if the requested column contains "a b X c d X X" and the position-list
** for 'X' is requested, the buffer returned may contain:
**
** 0x04 0x05 0x03 0x01 or 0x04 0x05 0x03 0x00
**
** This function works regardless of whether or not the phrase is deferred,
** incremental, or neither.
*/
SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(
Fts3Cursor *pCsr, /* FTS3 cursor object */
Fts3Expr *pExpr, /* Phrase to return doclist for */
int iCol, /* Column to return position list for */
char **ppOut /* OUT: Pointer to position list */
){
Fts3Phrase *pPhrase = pExpr->pPhrase;
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
char *pIter;
int iThis;
sqlite3_int64 iDocid;
typedef struct Fts3auxTable Fts3auxTable;
typedef struct Fts3auxCursor Fts3auxCursor;
struct Fts3auxTable {
sqlite3_vtab base; /* Base class used by SQLite core */
Fts3Table *pFts3Tab;
};
struct Fts3auxCursor {
sqlite3_vtab_cursor base; /* Base class used by SQLite core */
Fts3MultiSegReader csr; /* Must be right after "base" */
Fts3SegFilter filter;
char *zStop;
int nStop; /* Byte-length of string zStop */
int iLangid; /* Language id to query */
int isEof; /* True if cursor is at EOF */
sqlite3_int64 iRowid; /* Current rowid */
int iCol; /* Current value of 'col' column */
int nStat; /* Size of aStat[] array */
struct Fts3auxColstats {
sqlite3_int64 nDoc; /* 'documents' values for current csr row */
sqlite3_int64 nOcc; /* 'occurrences' values for current csr row */
} *aStat;
};
}
if( iLangid>=0 ){
pInfo->aConstraintUsage[iLangid].argvIndex = iNext++;
pInfo->estimatedCost--;
}
return SQLITE_OK;
}
/*
** xOpen - Open a cursor.
*/
static int fts3auxOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
Fts3auxCursor *pCsr; /* Pointer to cursor object to return */
UNUSED_PARAMETER(pVTab);
pCsr = (Fts3auxCursor *)sqlite3_malloc(sizeof(Fts3auxCursor));
if( !pCsr ) return SQLITE_NOMEM;
memset(pCsr, 0, sizeof(Fts3auxCursor));
*ppCsr = (sqlite3_vtab_cursor *)pCsr;
return SQLITE_OK;
}
/*
** xClose - Close a cursor.
*/
static int fts3auxCloseMethod(sqlite3_vtab_cursor *pCursor){
Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
sqlite3Fts3SegmentsClose(pFts3);
sqlite3Fts3SegReaderFinish(&pCsr->csr);
sqlite3_free((void *)pCsr->filter.zTerm);
sqlite3_free(pCsr->zStop);
sqlite3_free(pCsr->aStat);
sqlite3_free(pCsr);
return SQLITE_OK;
memset(&aNew[pCsr->nStat], 0,
sizeof(struct Fts3auxColstats) * (nSize - pCsr->nStat)
);
pCsr->aStat = aNew;
pCsr->nStat = nSize;
}
return SQLITE_OK;
}
/*
** xNext - Advance the cursor to the next row, if any.
*/
static int fts3auxNextMethod(sqlite3_vtab_cursor *pCursor){
Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
int rc;
/* Increment our pretend rowid value. */
pCsr->iRowid++;
for(pCsr->iCol++; pCsr->iCol<pCsr->nStat; pCsr->iCol++){
if( pCsr->aStat[pCsr->iCol].nDoc>0 ) return SQLITE_OK;
}
pCsr->iCol = 0;
rc = SQLITE_OK;
}else{
pCsr->isEof = 1;
}
return rc;
}
/*
** xFilter - Initialize a cursor to point at the start of its data.
*/
static int fts3auxFilterMethod(
sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */
int idxNum, /* Strategy index */
const char *idxStr, /* Unused */
int nVal, /* Number of elements in apVal */
sqlite3_value **apVal /* Arguments for the indexing scheme */
){
Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
int rc;
int isScan = 0;
int iLangVal = 0; /* Language id to query */
iGe = iNext++;
}
if( idxNum & FTS4AUX_LE_CONSTRAINT ){
iLe = iNext++;
}
}
if( iNext<nVal ){
iLangid = iNext++;
}
/* In case this cursor is being reused, close and zero it. */
testcase(pCsr->filter.zTerm);
sqlite3Fts3SegReaderFinish(&pCsr->csr);
sqlite3_free((void *)pCsr->filter.zTerm);
sqlite3_free(pCsr->aStat);
memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr);
pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;
if( iEq>=0 || iGe>=0 ){
);
if( rc==SQLITE_OK ){
rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
}
if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor);
return rc;
}
/*
** xEof - Return true if the cursor is at EOF, or false otherwise.
*/
static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){
Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
return pCsr->isEof;
}
/*
** xColumn - Return a column value.
*/
static int fts3auxColumnMethod(
sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */
sqlite3_context *pCtx, /* Context for sqlite3_result_xxx() calls */
int iCol /* Index of column to read value from */
){
Fts3auxCursor *p = (Fts3auxCursor *)pCursor;
assert( p->isEof==0 );
switch( iCol ){
case 0: /* term */
sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
break;
default: /* languageid */
assert( iCol==4 );
sqlite3_result_int(pCtx, p->iLangid);
break;
}
return SQLITE_OK;
}
/*
** xRowid - Return the current rowid for the cursor.
*/
static int fts3auxRowidMethod(
sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */
sqlite_int64 *pRowid /* OUT: Rowid value */
){
Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
*pRowid = pCsr->iRowid;
return SQLITE_OK;
}
/*
** Register the fts3aux module with database connection db. Return SQLITE_OK
** if successful or an error code if sqlite3_create_module() fails.
void *pRet = sqlite3_malloc(nByte);
if( pRet ) memset(pRet, 0, nByte);
return pRet;
}
SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(
sqlite3_tokenizer *pTokenizer,
int iLangid,
const char *z,
int n,
sqlite3_tokenizer_cursor **ppCsr
){
sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
sqlite3_tokenizer_cursor *pCsr = 0;
int rc;
rc = pModule->xOpen(pTokenizer, z, n, &pCsr);
assert( rc==SQLITE_OK || pCsr==0 );
if( rc==SQLITE_OK ){
pCsr->pTokenizer = pTokenizer;
if( pModule->iVersion>=1 ){
rc = pModule->xLanguageid(pCsr, iLangid);
if( rc!=SQLITE_OK ){
pModule->xClose(pCsr);
static int getNextToken(
ParseContext *pParse, /* fts3 query parse context */
int iCol, /* Value for Fts3Phrase.iColumn */
const char *z, int n, /* Input string */
Fts3Expr **ppExpr, /* OUT: expression */
int *pnConsumed /* OUT: Number of bytes consumed */
){
sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;
sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
int rc;
sqlite3_tokenizer_cursor *pCursor;
Fts3Expr *pRet = 0;
int i = 0;
/* Set variable i to the maximum number of bytes of input to tokenize. */
for(i=0; i<n; i++){
if( sqlite3_fts3_enable_parentheses && (z[i]=='(' || z[i]==')') ) break;
if( z[i]=='"' ) break;
}
*pnConsumed = i;
*/
static int getNextString(
ParseContext *pParse, /* fts3 query parse context */
const char *zInput, int nInput, /* Input string */
Fts3Expr **ppExpr /* OUT: expression */
){
sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;
sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
int rc;
Fts3Expr *p = 0;
sqlite3_tokenizer_cursor *pCursor = 0;
char *zTemp = 0;
int nTemp = 0;
const int nSpace = sizeof(Fts3Expr) + sizeof(Fts3Phrase);
int nToken = 0;
/* The final Fts3Expr data structure, including the Fts3Phrase,
** Fts3PhraseToken structures token buffers are all stored as a single
** allocation so that the expression can be freed with a single call to
** sqlite3_free(). Setting this up requires a two pass approach.
**
** The first pass, in the block below, uses a tokenizer cursor to iterate
** through the tokens in the expression. This pass uses fts3ReallocOrFree()
** to assemble data in two dynamic buffers:
**
** Buffer p: Points to the Fts3Expr structure, followed by the Fts3Phrase
** structure, followed by the array of Fts3PhraseToken
** structures. This pass only populates the Fts3PhraseToken array.
**
** Buffer zTemp: Contains copies of all tokens.
**
** The second pass, in the block that begins "if( rc==SQLITE_DONE )" below,
/*
** Class derived from sqlite3_tokenizer
*/
typedef struct porter_tokenizer {
sqlite3_tokenizer base; /* Base class */
} porter_tokenizer;
/*
** Class derived from sqlite3_tokenizer_cursor
*/
typedef struct porter_tokenizer_cursor {
sqlite3_tokenizer_cursor base;
const char *zInput; /* input we are tokenizing */
int nInput; /* size of the input */
int iOffset; /* current position in zInput */
int iToken; /* index of next token to be returned */
char *zToken; /* storage for current token */
int nAllocated; /* space allocated to zToken buffer */
} porter_tokenizer_cursor;
/*
** Create a new tokenizer instance.
*/
static int porterCreate(
int argc, const char * const *argv,
sqlite3_tokenizer **ppTokenizer
){
porter_tokenizer *t;
/*
** Destroy a tokenizer
*/
static int porterDestroy(sqlite3_tokenizer *pTokenizer){
sqlite3_free(pTokenizer);
return SQLITE_OK;
}
/*
** Prepare to begin tokenizing a particular string. The input
** string to be tokenized is zInput[0..nInput-1]. A cursor
** used to incrementally tokenize this string is returned in
** *ppCursor.
*/
static int porterOpen(
sqlite3_tokenizer *pTokenizer, /* The tokenizer */
const char *zInput, int nInput, /* String to be tokenized */
sqlite3_tokenizer_cursor **ppCursor /* OUT: Tokenization cursor */
){
porter_tokenizer_cursor *c;
UNUSED_PARAMETER(pTokenizer);
c = (porter_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));
if( c==NULL ) return SQLITE_NOMEM;
c->zInput = zInput;
if( zInput==0 ){
c->nInput = 0;
}else if( nInput<0 ){
c->nInput = (int)strlen(zInput);
}else{
c->nInput = nInput;
}
c->iOffset = 0; /* start tokenizing at the beginning */
c->iToken = 0;
c->zToken = NULL; /* no space allocated, yet. */
c->nAllocated = 0;
*ppCursor = &c->base;
return SQLITE_OK;
}
/*
** Close a tokenization cursor previously opened by a call to
** porterOpen() above.
*/
static int porterClose(sqlite3_tokenizer_cursor *pCursor){
porter_tokenizer_cursor *c = (porter_tokenizer_cursor *) pCursor;
sqlite3_free(c->zToken);
sqlite3_free(c);
return SQLITE_OK;
}
/*
** Vowel or consonant
*/
static const char cType[] = {
0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0,
1, 1, 1, 2, 1
/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 3x */
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 4x */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 5x */
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6x */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 7x */
};
#define isDelim(C) (((ch=C)&0x80)==0 && (ch<0x30 || !porterIdChar[ch-0x30]))
/*
** Extract the next token from a tokenization cursor. The cursor must
** have been opened by a prior call to porterOpen().
*/
static int porterNext(
sqlite3_tokenizer_cursor *pCursor, /* Cursor returned by porterOpen */
const char **pzToken, /* OUT: *pzToken is the token text */
int *pnBytes, /* OUT: Number of bytes in token */
int *piStartOffset, /* OUT: Starting offset of token */
int *piEndOffset, /* OUT: Ending offset of token */
int *piPosition /* OUT: Position integer of token */
){
porter_tokenizer_cursor *c = (porter_tokenizer_cursor *) pCursor;
const char *z = c->zInput;
while( c->iOffset<c->nInput ){
int iStartOffset, ch;
/* Scan past delimiter characters */
while( c->iOffset<c->nInput && isDelim(z[c->iOffset]) ){
c->iOffset++;
}
**
*/
static void testFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
Fts3Hash *pHash;
sqlite3_tokenizer_module *p;
sqlite3_tokenizer *pTokenizer = 0;
sqlite3_tokenizer_cursor *pCsr = 0;
const char *zErr = 0;
const char *zName;
int nName;
const char *zInput;
int nInput;
const char *azArg[64];
/* #include <stdlib.h> */
/* #include <stdio.h> */
/* #include <string.h> */
typedef struct simple_tokenizer {
sqlite3_tokenizer base;
char delim[128]; /* flag ASCII delimiters */
} simple_tokenizer;
typedef struct simple_tokenizer_cursor {
sqlite3_tokenizer_cursor base;
const char *pInput; /* input we are tokenizing */
int nBytes; /* size of the input */
int iOffset; /* current position in pInput */
int iToken; /* index of next token to be returned */
char *pToken; /* storage for current token */
int nTokenAllocated; /* space allocated to zToken buffer */
} simple_tokenizer_cursor;
static int simpleDelim(simple_tokenizer *t, unsigned char c){
return c<0x80 && t->delim[c];
}
static int fts3_isalnum(int x){
return (x>='0' && x<='9') || (x>='A' && x<='Z') || (x>='a' && x<='z');
}
/*
/*
** Destroy a tokenizer
*/
static int simpleDestroy(sqlite3_tokenizer *pTokenizer){
sqlite3_free(pTokenizer);
return SQLITE_OK;
}
/*
** Prepare to begin tokenizing a particular string. The input
** string to be tokenized is pInput[0..nBytes-1]. A cursor
** used to incrementally tokenize this string is returned in
** *ppCursor.
*/
static int simpleOpen(
sqlite3_tokenizer *pTokenizer, /* The tokenizer */
const char *pInput, int nBytes, /* String to be tokenized */
sqlite3_tokenizer_cursor **ppCursor /* OUT: Tokenization cursor */
){
simple_tokenizer_cursor *c;
UNUSED_PARAMETER(pTokenizer);
c = (simple_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));
if( c==NULL ) return SQLITE_NOMEM;
c->pInput = pInput;
if( pInput==0 ){
c->nBytes = 0;
}else if( nBytes<0 ){
c->nBytes = (int)strlen(pInput);
}else{
c->nBytes = nBytes;
}
c->iOffset = 0; /* start tokenizing at the beginning */
c->iToken = 0;
c->pToken = NULL; /* no space allocated, yet. */
c->nTokenAllocated = 0;
*ppCursor = &c->base;
return SQLITE_OK;
}
/*
** Close a tokenization cursor previously opened by a call to
** simpleOpen() above.
*/
static int simpleClose(sqlite3_tokenizer_cursor *pCursor){
simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;
sqlite3_free(c->pToken);
sqlite3_free(c);
return SQLITE_OK;
}
/*
** Extract the next token from a tokenization cursor. The cursor must
** have been opened by a prior call to simpleOpen().
*/
static int simpleNext(
sqlite3_tokenizer_cursor *pCursor, /* Cursor returned by simpleOpen */
const char **ppToken, /* OUT: *ppToken is the token text */
int *pnBytes, /* OUT: Number of bytes in token */
int *piStartOffset, /* OUT: Starting offset of token */
int *piEndOffset, /* OUT: Ending offset of token */
int *piPosition /* OUT: Position integer of token */
){
simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;
simple_tokenizer *t = (simple_tokenizer *) pCursor->pTokenizer;
unsigned char *p = (unsigned char *)c->pInput;
while( c->iOffset<c->nBytes ){
int iStartOffset;
/* Scan past delimiter characters */
while( c->iOffset<c->nBytes && simpleDelim(t, p[c->iOffset]) ){
c->iOffset++;
}
/*
** Virtual table structure.
*/
struct Fts3tokTable {
sqlite3_vtab base; /* Base class used by SQLite core */
const sqlite3_tokenizer_module *pMod;
sqlite3_tokenizer *pTok;
};
/*
** Virtual table cursor structure.
*/
struct Fts3tokCursor {
sqlite3_vtab_cursor base; /* Base class used by SQLite core */
char *zInput; /* Input string */
sqlite3_tokenizer_cursor *pCsr; /* Cursor to iterate through zInput */
int iRowid; /* Current 'rowid' value */
const char *zToken; /* Current 'token' value */
int nToken; /* Size of zToken in bytes */
int iStart; /* Current 'start' value */
int iEnd; /* Current 'end' value */
int iPos; /* Current 'pos' value */
};
/*
** Query FTS for the tokenizer implementation named zName.
}
}
pInfo->idxNum = 0;
assert( pInfo->estimatedCost>1000000.0 );
return SQLITE_OK;
}
/*
** xOpen - Open a cursor.
*/
static int fts3tokOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
Fts3tokCursor *pCsr;
UNUSED_PARAMETER(pVTab);
pCsr = (Fts3tokCursor *)sqlite3_malloc(sizeof(Fts3tokCursor));
if( pCsr==0 ){
return SQLITE_NOMEM;
}
memset(pCsr, 0, sizeof(Fts3tokCursor));
*ppCsr = (sqlite3_vtab_cursor *)pCsr;
return SQLITE_OK;
}
/*
** Reset the tokenizer cursor passed as the only argument. As if it had
** just been returned by fts3tokOpenMethod().
*/
static void fts3tokResetCursor(Fts3tokCursor *pCsr){
if( pCsr->pCsr ){
Fts3tokTable *pTab = (Fts3tokTable *)(pCsr->base.pVtab);
pTab->pMod->xClose(pCsr->pCsr);
pCsr->pCsr = 0;
}
sqlite3_free(pCsr->zInput);
pCsr->zInput = 0;
pCsr->zToken = 0;
pCsr->nToken = 0;
pCsr->iStart = 0;
pCsr->iEnd = 0;
pCsr->iPos = 0;
pCsr->iRowid = 0;
}
/*
** xClose - Close a cursor.
*/
static int fts3tokCloseMethod(sqlite3_vtab_cursor *pCursor){
Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
fts3tokResetCursor(pCsr);
sqlite3_free(pCsr);
return SQLITE_OK;
}
/*
** xNext - Advance the cursor to the next row, if any.
*/
static int fts3tokNextMethod(sqlite3_vtab_cursor *pCursor){
Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
int rc; /* Return code */
pCsr->iRowid++;
rc = pTab->pMod->xNext(pCsr->pCsr,
&pCsr->zToken, &pCsr->nToken,
&pCsr->iStart, &pCsr->iEnd, &pCsr->iPos
);
if( rc!=SQLITE_OK ){
fts3tokResetCursor(pCsr);
if( rc==SQLITE_DONE ) rc = SQLITE_OK;
}
return rc;
}
/*
** xFilter - Initialize a cursor to point at the start of its data.
*/
static int fts3tokFilterMethod(
sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */
int idxNum, /* Strategy index */
const char *idxStr, /* Unused */
int nVal, /* Number of elements in apVal */
sqlite3_value **apVal /* Arguments for the indexing scheme */
){
int rc = SQLITE_ERROR;
Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
UNUSED_PARAMETER(idxStr);
UNUSED_PARAMETER(nVal);
pCsr->pCsr->pTokenizer = pTab->pTok;
}
}
}
if( rc!=SQLITE_OK ) return rc;
return fts3tokNextMethod(pCursor);
}
/*
** xEof - Return true if the cursor is at EOF, or false otherwise.
*/
static int fts3tokEofMethod(sqlite3_vtab_cursor *pCursor){
Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
return (pCsr->zToken==0);
}
/*
** xColumn - Return a column value.
*/
static int fts3tokColumnMethod(
sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */
sqlite3_context *pCtx, /* Context for sqlite3_result_xxx() calls */
int iCol /* Index of column to read value from */
){
Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
/* CREATE TABLE x(input, token, start, end, position) */
switch( iCol ){
case 0:
sqlite3_result_text(pCtx, pCsr->zInput, -1, SQLITE_TRANSIENT);
break;
break;
default:
assert( iCol==4 );
sqlite3_result_int(pCtx, pCsr->iPos);
break;
}
return SQLITE_OK;
}
/*
** xRowid - Return the current rowid for the cursor.
*/
static int fts3tokRowidMethod(
sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */
sqlite_int64 *pRowid /* OUT: Rowid value */
){
Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
*pRowid = (sqlite3_int64)pCsr->iRowid;
return SQLITE_OK;
}
/*
** Register the fts3tok module with database connection db. Return SQLITE_OK
** if successful or an error code if sqlite3_create_module() fails.
int nData;
char *aData;
int nSpace;
sqlite3_int64 iLastDocid;
sqlite3_int64 iLastCol;
sqlite3_int64 iLastPos;
};
/*
** Each cursor has a (possibly empty) linked list of the following objects.
*/
struct Fts3DeferredToken {
Fts3PhraseToken *pToken; /* Pointer to corresponding expr token */
int iCol; /* Column token must occur in */
Fts3DeferredToken *pNext; /* Next in list of deferred tokens */
PendingList *pList; /* Doclist is assembled here */
};
/*
** An instance of this structure is used to iterate through the terms on
int iStart = 0;
int iEnd = 0;
int iPos = 0;
int nWord = 0;
char const *zToken;
int nToken = 0;
sqlite3_tokenizer *pTokenizer = p->pTokenizer;
sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
sqlite3_tokenizer_cursor *pCsr;
int (*xNext)(sqlite3_tokenizer_cursor *pCursor,
const char**,int*,int*,int*,int*);
assert( pTokenizer && pModule );
/* If the user has inserted a NULL value, this function may be called with
** zText==0. In this case, add zero token entries to the hash table and
** return early. */
if( zText==0 ){
*pnWord = 0;
return SQLITE_OK;
);
while( pReader->pBlob && rc==SQLITE_OK
&& (pFrom - pReader->aNode + nByte)>pReader->nPopulate
){
rc = fts3SegReaderIncrRead(pReader);
}
return rc;
}
/*
** Set an Fts3SegReader cursor to point at EOF.
*/
static void fts3SegReaderSetEof(Fts3SegReader *pSeg){
if( !fts3SegReaderIsRootOnly(pSeg) ){
sqlite3_free(pSeg->aNode);
sqlite3_blob_close(pSeg->pBlob);
pSeg->pBlob = 0;
}
pSeg->aNode = 0;
}
rc = rc2;
}
}
}
return rc;
}
/*
** This function opens a cursor used to read the input data for an
** incremental merge operation. Specifically, it opens a cursor to scan
** the oldest nSeg segments (idx=0 through idx=(nSeg-1)) in absolute
** level iAbsLevel.
*/
static int fts3IncrmergeCsr(
Fts3Table *p, /* FTS3 table handle */
sqlite3_int64 iAbsLevel, /* Absolute level to open */
int nSeg, /* Number of segments to merge */
Fts3MultiSegReader *pCsr /* Cursor object to populate */
){
int rc; /* Return Code */
memcpy(&pNode->a[pNode->n], aDoclist, nDoclist);
pNode->n += nDoclist;
}
assert( pNode->n<=pNode->nAlloc );
return SQLITE_OK;
}
/*
** Append the current term and doclist pointed to by cursor pCsr to the
** appendable b-tree segment opened for writing by pWriter.
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise.
*/
static int fts3IncrmergeAppend(
Fts3Table *p, /* Fts3 table handle */
IncrmergeWriter *pWriter, /* Writer object */
Fts3MultiSegReader *pCsr /* Cursor containing term and doclist */
){
const char *zTerm = pCsr->zTerm;
** iAbsLevel.
**
** Each input segment is either removed from the db completely (if all of
** its data was copied to the output segment by the incrmerge operation)
** or modified in place so that it no longer contains those entries that
** have been duplicated in the output segment.
*/
static int fts3IncrmergeChomp(
Fts3Table *p, /* FTS table handle */
sqlite3_int64 iAbsLevel, /* Absolute level containing segments */
Fts3MultiSegReader *pCsr, /* Chomp all segments opened by this cursor */
int *pnRem /* Number of segments not deleted */
){
int i;
int nRem = 0;
int rc = SQLITE_OK;
for(i=pCsr->nSegment-1; i>=0 && rc==SQLITE_OK; i--){
Fts3SegReader *pSeg = 0;
int j;
** Incremental merges happen nMin segments at a time. The segments
** to be merged are the nMin oldest segments (the ones with the smallest
** values for the _segdir.idx field) in the highest level that contains
** at least nMin segments. Multiple merges might occur in an attempt to
** write the quota of nMerge leaf blocks.
*/
SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
int rc; /* Return code */
int nRem = nMerge; /* Number of leaf pages yet to be written */
Fts3MultiSegReader *pCsr; /* Cursor used to read input data */
Fts3SegFilter *pFilter; /* Filter used with cursor pCsr */
IncrmergeWriter *pWriter; /* Writer object */
int nSeg = 0; /* Number of input segments */
sqlite3_int64 iAbsLevel = 0; /* Absolute level number to work on */
Blob hint = {0, 0, 0}; /* Hint read from %_stat table */
int bDirtyHint = 0; /* True if blob 'hint' has been modified */
/* Allocate space for the cursor, filter and writer objects */
const int nAlloc = sizeof(*pCsr) + sizeof(*pFilter) + sizeof(*pWriter);
pWriter = (IncrmergeWriter *)sqlite3_malloc(nAlloc);
if( !pWriter ) return SQLITE_NOMEM;
pFilter = (Fts3SegFilter *)&pWriter[1];
pCsr = (Fts3MultiSegReader *)&pFilter[1];
rc = fts3IncrmergeHintLoad(p, &hint);
while( rc==SQLITE_OK && nRem>0 ){
const i64 nMod = FTS3_SEGDIR_MAXLEVEL * p->nIndex;
sqlite3_stmt *pFindLevel = 0; /* SQL used to determine iAbsLevel */
** is removed from the hint blob. */
hint.n = nHint;
}
}
/* If nSeg is less that zero, then there is no level with at least
** nMin segments and no hint in the %_stat table. No work to do.
** Exit early in this case. */
if( nSeg<0 ) break;
/* Open a cursor to iterate through the contents of the oldest nSeg
** indexes of absolute level iAbsLevel. If this cursor is opened using
** the 'hint' parameters, it is possible that there are less than nSeg
** segments available in level iAbsLevel. In this case, no work is
** done on iAbsLevel - fall through to the next iteration of the loop
** to start work on some other level. */
memset(pWriter, 0, nAlloc);
pFilter->flags = FTS3_SEGMENT_REQUIRE_POS;
if( rc==SQLITE_OK ){
rc = fts3IncrmergeOutputIdx(p, iAbsLevel, &iIdx);
assert( bUseHint==1 || bUseHint==0 );
while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
i64 iDocid = sqlite3_column_int64(pStmt, 0);
int iLang = langidFromSelect(p, pStmt);
int iCol;
for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
if( p->abNotindexed[iCol]==0 ){
const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);
int nText = sqlite3_column_bytes(pStmt, iCol+1);
sqlite3_tokenizer_cursor *pT = 0;
rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText,&pT);
while( rc==SQLITE_OK ){
char const *zToken; /* Buffer containing token */
int nToken = 0; /* Number of bytes in token */
int iDum1 = 0, iDum2 = 0; /* Dummy variables */
int iPos = 0; /* Position of token in zText */
rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);
if( rc==SQLITE_OK ){
Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
sqlite3_tokenizer *pT = p->pTokenizer;
sqlite3_tokenizer_module const *pModule = pT->pModule;
assert( pCsr->isRequireSeek==0 );
iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
if( p->abNotindexed[i]==0 ){
const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
sqlite3_tokenizer_cursor *pTC = 0;
rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
while( rc==SQLITE_OK ){
char const *zToken; /* Buffer containing token */
int nToken = 0; /* Number of bytes in token */
int iDum1 = 0, iDum2 = 0; /* Dummy variables */
int iPos = 0; /* Position of token in zText */
rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
*ppData = pRet;
memcpy(pRet, &p->pList->aData[nSkip], *pnData);
return SQLITE_OK;
}
/*
** Add an entry for token pToken to the pCsr->pDeferred list.
*/
SQLITE_PRIVATE int sqlite3Fts3DeferToken(
Fts3Cursor *pCsr, /* Fts3 table cursor */
Fts3PhraseToken *pToken, /* Token to defer */
int iCol /* Column that token must appear in (or -1) */
){
Fts3DeferredToken *pDeferred;
pDeferred = sqlite3_malloc(sizeof(*pDeferred));
if( !pDeferred ){
return SQLITE_NOMEM;
}
memset(pDeferred, 0, sizeof(*pDeferred));
pDeferred->pToken = pToken;
UNUSED_PARAMETER(iPhrase);
p->nPhrase++;
p->nToken += pPhrase->nToken;
return rc;
}
/*
** Load the doclists for each phrase in the query associated with FTS3 cursor
** pCsr.
**
** If pnPhrase is not NULL, then *pnPhrase is set to the number of matchable
** phrases in the expression (all phrases except those directly or
** indirectly descended from the right-hand-side of a NOT operator). If
** pnToken is not NULL, then it is set to the number of tokens in all
** matchable phrases of the expression.
*/
static int fts3ExprLoadDoclists(
Fts3Cursor *pCsr, /* Fts3 cursor for current query */
int *pnPhrase, /* OUT: Number of phrases in query */
int *pnToken /* OUT: Number of tokens in query */
){
int rc; /* Return Code */
LoadDoclistCtx sCtx = {0,0,0}; /* Context for fts3ExprIterate() */
sCtx.pCsr = pCsr;
rc = fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb, (void *)&sCtx);
if( pnPhrase ) *pnPhrase = sCtx.nPhrase;
if( pnToken ) *pnToken = sCtx.nToken;
return rc;
** nDesired tokens to the right of the snippet. If so, *piPos and
** *pHlMask are updated to shift the snippet nDesired tokens to the
** right. Otherwise, the snippet is shifted by the number of tokens
** available.
*/
if( nDesired>0 ){
int nShift; /* Number of tokens to shift snippet by */
int iCurrent = 0; /* Token counter */
int rc; /* Return Code */
sqlite3_tokenizer_module *pMod;
sqlite3_tokenizer_cursor *pC;
pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
/* Open a cursor on zDoc/nDoc. Check if there are (nSnippet+nDesired)
** or more tokens in zDoc/nDoc.
*/
rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, iLangid, zDoc, nDoc, &pC);
if( rc!=SQLITE_OK ){
return rc;
}
while( rc==SQLITE_OK && iCurrent<(nSnippet+nDesired) ){
const char *ZDUMMY; int DUMMY1 = 0, DUMMY2 = 0, DUMMY3 = 0;
rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &DUMMY2, &DUMMY3, &iCurrent);
}
if( nShift>0 ){
*piPos += nShift;
*pHlmask = hlmask >> nShift;
}
}
}
return SQLITE_OK;
}
/*
** Extract the snippet text for fragment pFragment from cursor pCsr and
** append it to string buffer pOut.
*/
static int fts3SnippetText(
Fts3Cursor *pCsr, /* FTS3 Cursor */
SnippetFragment *pFragment, /* Snippet to extract */
int iFragment, /* Fragment number */
int isLast, /* True for final fragment in snippet */
int nSnippet, /* Number of tokens in extracted snippet */
const char *zOpen, /* String inserted before highlighted term */
const char *zClose, /* String inserted after highlighted term */
int rc; /* Return code */
const char *zDoc; /* Document text to extract snippet from */
int nDoc; /* Size of zDoc in bytes */
int iCurrent = 0; /* Current token number of document */
int iEnd = 0; /* Byte offset of end of current token */
int isShiftDone = 0; /* True after snippet is shifted */
int iPos = pFragment->iPos; /* First token of snippet */
u64 hlmask = pFragment->hlmask; /* Highlight-mask for snippet */
int iCol = pFragment->iCol+1; /* Query column to extract text from */
sqlite3_tokenizer_module *pMod; /* Tokenizer module methods object */
sqlite3_tokenizer_cursor *pC; /* Tokenizer cursor open on zDoc/nDoc */
zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol);
if( zDoc==0 ){
if( sqlite3_column_type(pCsr->pStmt, iCol)!=SQLITE_NULL ){
return SQLITE_NOMEM;
}
return SQLITE_OK;
}
nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol);
/* Open a token cursor on the document. */
pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid, zDoc,nDoc,&pC);
if( rc!=SQLITE_OK ){
return rc;
}
while( rc==SQLITE_OK ){
const char *ZDUMMY; /* Dummy argument used with tokenizer */
int DUMMY1 = -1; /* Dummy argument used with tokenizer */
int iBegin = 0; /* Offset in zDoc of start of token */
** If bGlobal is true, then populate all fields of the matchinfo() output.
** If it is false, then assume that those fields that do not change between
** rows (i.e. FTS3_MATCHINFO_NPHRASE, NCOL, NDOC, AVGLENGTH and part of HITS)
** have already been populated.
**
** Return SQLITE_OK if successful, or an SQLite error code if an error
** occurs. If a value other than SQLITE_OK is returned, the state the
** pInfo->aMatchinfo[] buffer is left in is undefined.
*/
static int fts3MatchinfoValues(
Fts3Cursor *pCsr, /* FTS3 cursor object */
int bGlobal, /* True to grab the global stats */
MatchInfo *pInfo, /* Matchinfo context object */
const char *zArg /* Matchinfo format string */
){
int rc = SQLITE_OK;
int i;
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
sqlite3_stmt *pSelect = 0;
for(i=0; rc==SQLITE_OK && zArg[i]; i++){
rc = SQLITE_NOMEM;
goto offsets_out;
}
sCtx.iDocid = pCsr->iPrevId;
sCtx.pCsr = pCsr;
/* Loop through the table columns, appending offset information to
** string-buffer res for each column.
*/
for(iCol=0; iCol<pTab->nColumn; iCol++){
sqlite3_tokenizer_cursor *pC; /* Tokenizer cursor */
const char *ZDUMMY; /* Dummy argument used with xNext() */
int NDUMMY = 0; /* Dummy argument used with xNext() */
int iStart = 0;
int iEnd = 0;
int iCurrent = 0;
const char *zDoc;
int nDoc;
/* Initialize the contents of sCtx.aTerm[] for column iCol. There is
** no way that this operation can fail, so the return code from
sqlite3_result_text(pCtx, res.z, res.n-1, sqlite3_free);
}
return;
}
/*
** Implementation of matchinfo() function.
*/
SQLITE_PRIVATE void sqlite3Fts3Matchinfo(
sqlite3_context *pContext, /* Function call context */
Fts3Cursor *pCsr, /* FTS3 table cursor */
const char *zArg /* Second arg to matchinfo() function */
){
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
int rc;
int i;
const char *zFormat;
if( zArg ){
for(i=0; zArg[i]; i++){
char *zErr = 0;
*zOut++ = 0xF0 + (u8)((c>>18) & 0x07); \
*zOut++ = 0x80 + (u8)((c>>12) & 0x3F); \
*zOut++ = 0x80 + (u8)((c>>6) & 0x3F); \
*zOut++ = 0x80 + (u8)(c & 0x3F); \
} \
}
#endif /* ifndef SQLITE_AMALGAMATION */
typedef struct unicode_tokenizer unicode_tokenizer;
typedef struct unicode_cursor unicode_cursor;
struct unicode_tokenizer {
sqlite3_tokenizer base;
int bRemoveDiacritic;
int nException;
int *aiException;
};
struct unicode_cursor {
sqlite3_tokenizer_cursor base;
const unsigned char *aInput; /* Input text being tokenized */
int nInput; /* Size of aInput[] in bytes */
int iOff; /* Current offset within aInput[] */
int iToken; /* Index of next token to be returned */
char *zToken; /* storage for current token */
int nAlloc; /* space allocated at zToken */
};
/*
if( rc!=SQLITE_OK ){
unicodeDestroy((sqlite3_tokenizer *)pNew);
pNew = 0;
}
*pp = (sqlite3_tokenizer *)pNew;
return rc;
}
/*
** Prepare to begin tokenizing a particular string. The input
** string to be tokenized is pInput[0..nBytes-1]. A cursor
** used to incrementally tokenize this string is returned in
** *ppCursor.
*/
static int unicodeOpen(
sqlite3_tokenizer *p, /* The tokenizer */
const char *aInput, /* Input string */
int nInput, /* Size of string aInput in bytes */
sqlite3_tokenizer_cursor **pp /* OUT: New cursor object */
){
unicode_cursor *pCsr;
pCsr = (unicode_cursor *)sqlite3_malloc(sizeof(unicode_cursor));
if( pCsr==0 ){
return SQLITE_NOMEM;
}
memset(pCsr, 0, sizeof(unicode_cursor));
pCsr->aInput = (const unsigned char *)aInput;
if( aInput==0 ){
pCsr->nInput = 0;
}else if( nInput<0 ){
pCsr->nInput = (int)strlen(aInput);
}else{
pCsr->nInput = nInput;
}
*pp = &pCsr->base;
UNUSED_PARAMETER(p);
return SQLITE_OK;
}
/*
** Close a tokenization cursor previously opened by a call to
** simpleOpen() above.
*/
static int unicodeClose(sqlite3_tokenizer_cursor *pCursor){
unicode_cursor *pCsr = (unicode_cursor *) pCursor;
sqlite3_free(pCsr->zToken);
sqlite3_free(pCsr);
return SQLITE_OK;
}
/*
** Extract the next token from a tokenization cursor. The cursor must
** have been opened by a prior call to simpleOpen().
*/
static int unicodeNext(
sqlite3_tokenizer_cursor *pC, /* Cursor returned by simpleOpen */
const char **paToken, /* OUT: Token text */
int *pnToken, /* OUT: Number of bytes at *paToken */
int *piStart, /* OUT: Starting offset of token */
int *piEnd, /* OUT: Ending offset of token */
int *piPos /* OUT: Position integer of token */
){
unicode_cursor *pCsr = (unicode_cursor *)pC;
unicode_tokenizer *p = ((unicode_tokenizer *)pCsr->base.pTokenizer);
int iCode = 0;
char *zOut;
const unsigned char *z = &pCsr->aInput[pCsr->iOff];
const unsigned char *zStart = z;
const unsigned char *zEnd;
const unsigned char *zTerm = &pCsr->aInput[pCsr->nInput];
/* Scan past any delimiter characters before the start of the next token.
** Return SQLITE_DONE early if this takes us all the way to the end of
pCsr->nAlloc += 64;
}
/* Write the folded case of the last character read to the output */
zEnd = z;
iOut = sqlite3FtsUnicodeFold(iCode, p->bRemoveDiacritic);
if( iOut ){
WRITE_UTF8(zOut, iOut);
}
/* If the cursor is not at EOF, read the next character */
if( z>=zTerm ) break;
READ_UTF8(z, zTerm, iCode);
}while( unicodeIsAlnum(p, iCode)
|| sqlite3FtsUnicodeIsdiacritic(iCode)
);
/* Set the output variables and return. */
pCsr->iOff = (int)(z - pCsr->aInput);
*paToken = pCsr->zToken;
*pnToken = (int)(zOut - pCsr->zToken);
** The smallest possible node-size is (512-64)==448 bytes. And the largest
** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).
** Therefore all non-root nodes must contain at least 3 entries. Since
** 2^40 is greater than 2^64, an r-tree structure always has a depth of
** 40 or less.
*/
#define RTREE_MAX_DEPTH 40
/*
** Number of entries in the cursor RtreeNode cache. The first entry is
** used to cache the RtreeNode for RtreeCursor.sPoint. The remaining
** entries cache the RtreeNode for the first elements of the priority queue.
*/
#define RTREE_CACHE_SZ 5
/*
** An rtree cursor object.
*/
struct RtreeCursor {
sqlite3_vtab_cursor base; /* Base class. Must be first */
u8 atEOF; /* True if at end of search */
u8 bPoint; /* True if sPoint is valid */
int iStrategy; /* Copy of idxNum search parameter */
int nConstraint; /* Number of entries in aConstraint */
RtreeConstraint *aConstraint; /* Search constraints. */
int nPointAlloc; /* Number of slots allocated for aPoint[] */
int nPoint; /* Number of slots used in aPoint[] */
int mxLevel; /* iLevel value for root of the tree */
RtreeSearchPoint *aPoint; /* Priority queue for search points */
RtreeSearchPoint sPoint; /* Cached next search point */
if( rc==SQLITE_OK ){
rtreeRelease(pRtree);
}
return rc;
}
/*
** Rtree virtual table module xOpen method.
*/
static int rtreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
int rc = SQLITE_NOMEM;
RtreeCursor *pCsr;
pCsr = (RtreeCursor *)sqlite3_malloc(sizeof(RtreeCursor));
if( pCsr ){
memset(pCsr, 0, sizeof(RtreeCursor));
pCsr->base.pVtab = pVTab;
rc = SQLITE_OK;
}
*ppCursor = (sqlite3_vtab_cursor *)pCsr;
return rc;
}
/*
** Free the RtreeCursor.aConstraint[] array and its contents.
*/
static void freeCursorConstraints(RtreeCursor *pCsr){
if( pCsr->aConstraint ){
}
}
sqlite3_free(pCsr->aConstraint);
pCsr->aConstraint = 0;
}
}
/*
** Rtree virtual table module xClose method.
*/
static int rtreeClose(sqlite3_vtab_cursor *cur){
Rtree *pRtree = (Rtree *)(cur->pVtab);
int ii;
RtreeCursor *pCsr = (RtreeCursor *)cur;
freeCursorConstraints(pCsr);
sqlite3_free(pCsr->aPoint);
for(ii=0; ii<RTREE_CACHE_SZ; ii++) nodeRelease(pRtree, pCsr->aNode[ii]);
sqlite3_free(pCsr);
return SQLITE_OK;
}
/*
** Rtree virtual table module xEof method.
**
** Return non-zero if the cursor does not currently point to a valid
** record (i.e if the scan has finished), or zero otherwise.
*/
static int rtreeEof(sqlite3_vtab_cursor *cur){
RtreeCursor *pCsr = (RtreeCursor *)cur;
return pCsr->atEOF;
}
/*
** Convert raw bits from the on-disk RTree record into a coordinate value.
** The on-disk format is big-endian and needs to be converted for little-
** endian platforms. The on-disk record stores integer coordinates if
** eInt is true and it stores 32-bit floating point records if eInt is
** false. a[] is the four bytes of the on-disk record to be decoded.
const RtreeSearchPoint *pB
){
if( pA->rScore<pB->rScore ) return -1;
if( pA->rScore>pB->rScore ) return +1;
if( pA->iLevel<pB->iLevel ) return -1;
if( pA->iLevel>pB->iLevel ) return +1;
return 0;
}
/*
** Interchange to search points in a cursor.
*/
static void rtreeSearchPointSwap(RtreeCursor *p, int i, int j){
RtreeSearchPoint t = p->aPoint[i];
assert( i<j );
p->aPoint[i] = p->aPoint[j];
p->aPoint[j] = t;
i++; j++;
if( i<RTREE_CACHE_SZ ){
if( j>=RTREE_CACHE_SZ ){
nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
id = ii ? pCur->aPoint[0].id : pCur->sPoint.id;
*pRC = nodeAcquire(RTREE_OF_CURSOR(pCur), id, 0, &pCur->aNode[ii]);
}
return pCur->aNode[ii];
}
/*
** Push a new element onto the priority queue
*/
static RtreeSearchPoint *rtreeEnqueue(
RtreeCursor *pCur, /* The cursor */
RtreeDValue rScore, /* Score for the new search point */
u8 iLevel /* Level for the new search point */
){
int i, j;
RtreeSearchPoint *pNew;
if( pCur->nPoint>=pCur->nPointAlloc ){
int nNew = pCur->nPointAlloc*2 + 8;
pNew = sqlite3_realloc(pCur->aPoint, nNew*sizeof(pCur->aPoint[0]));
if( pNew==0 ) return 0;
pCur->aPoint = pNew;
pNew = pParent;
}
return pNew;
}
/*
** Allocate a new RtreeSearchPoint and return a pointer to it. Return
** NULL if malloc fails.
*/
static RtreeSearchPoint *rtreeSearchPointNew(
RtreeCursor *pCur, /* The cursor */
RtreeDValue rScore, /* Score for the new search point */
u8 iLevel /* Level for the new search point */
){
RtreeSearchPoint *pNew, *pFirst;
pFirst = rtreeSearchPointFirst(pCur);
pCur->anQueue[iLevel]++;
if( pFirst==0
|| pFirst->rScore>rScore
|| (pFirst->rScore==rScore && pFirst->iLevel>iLevel)
){
}else{
break;
}
}
}
}
}
/*
** Continue the search on cursor pCur until the front of the queue
** contains an entry suitable for returning as a result-set row,
** or until the RtreeSearchPoint queue is empty, indicating that the
** query has completed.
*/
static int rtreeStepToLeaf(RtreeCursor *pCur){
RtreeSearchPoint *p;
Rtree *pRtree = RTREE_OF_CURSOR(pCur);
RtreeNode *pNode;
int eWithin;
int rc = SQLITE_OK;
rtreeSearchPointPop(pCur);
}
}
pCur->atEOF = p==0;
return SQLITE_OK;
}
/*
** Rtree virtual table module xNext method.
*/
static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
int rc = SQLITE_OK;
/* Move to the next entry that matches the configured constraints. */
RTREE_QUEUE_TRACE(pCsr, "POP-Nx:");
rtreeSearchPointPop(pCsr);
rc = rtreeStepToLeaf(pCsr);
return rc;
}
/*
** Rtree virtual table module xRowid method.
*/
static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
int rc = SQLITE_OK;
RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
if( rc==SQLITE_OK && p ){
*pRowid = nodeGetRowid(RTREE_OF_CURSOR(pCsr), pNode, p->iCell);
}
return rc;
}
/*
** Rtree virtual table module xColumn method.
*/
static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
Rtree *pRtree = (Rtree *)cur->pVtab;
RtreeCursor *pCsr = (RtreeCursor *)cur;
RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
RtreeCoord c;
int rc = SQLITE_OK;
RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
if( rc ) return rc;
if( p==0 ) return SQLITE_OK;
if( i==0 ){
pCons->u.xQueryFunc = pBlob->cb.xQueryFunc;
}
pCons->pInfo = pInfo;
return SQLITE_OK;
}
/*
** Rtree virtual table module xFilter method.
*/
static int rtreeFilter(
sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv
){
Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
RtreeNode *pRoot = 0;
int ii;
int rc = SQLITE_OK;
int iCell = 0;
rtreeReference(pRtree);
/* Reset the cursor to the same state as rtreeOpen() leaves it in. */
freeCursorConstraints(pCsr);
sqlite3_free(pCsr->aPoint);
memset(pCsr, 0, sizeof(RtreeCursor));
pCsr->base.pVtab = (sqlite3_vtab*)pRtree;
pCsr->iStrategy = idxNum;
if( idxNum==1 ){
/* Special case - lookup by rowid. */
RtreeNode *pLeaf; /* Leaf on which the required cell resides */
RtreeSearchPoint *p; /* Search point for the the leaf */
return rc;
}
static sqlite3_module rtreeModule = {
0, /* iVersion */
rtreeCreate, /* xCreate - create a table */
rtreeConnect, /* xConnect - connect to an existing table */
rtreeBestIndex, /* xBestIndex - Determine search strategy */
rtreeDisconnect, /* xDisconnect - Disconnect from a table */
rtreeDestroy, /* xDestroy - Drop a table */
rtreeOpen, /* xOpen - open a cursor */
rtreeClose, /* xClose - close a cursor */
rtreeFilter, /* xFilter - configure scan constraints */
rtreeNext, /* xNext - advance a cursor */
rtreeEof, /* xEof */
rtreeColumn, /* xColumn - read data */
rtreeRowid, /* xRowid - read data */
rtreeUpdate, /* xUpdate - write data */
0, /* xBegin - begin transaction */
0, /* xSync - sync transaction */
0, /* xCommit - commit transaction */
0, /* xRollback - rollback transaction */
0, /* xFindFunction - function overloading */
rtreeRename, /* xRename - rename the table */
typedef struct IcuTokenizer IcuTokenizer;
typedef struct IcuCursor IcuCursor;
struct IcuTokenizer {
sqlite3_tokenizer base;
char *zLocale;
};
struct IcuCursor {
sqlite3_tokenizer_cursor base;
UBreakIterator *pIter; /* ICU break-iterator object */
int nChar; /* Number of UChar elements in pInput */
UChar *aChar; /* Copy of input using utf-16 encoding */
int *aOffset; /* Offsets of each character in utf-8 input */
int nBuffer;
char *zBuffer;
int iToken;
** Destroy a tokenizer
*/
static int icuDestroy(sqlite3_tokenizer *pTokenizer){
IcuTokenizer *p = (IcuTokenizer *)pTokenizer;
sqlite3_free(p);
return SQLITE_OK;
}
/*
** Prepare to begin tokenizing a particular string. The input
** string to be tokenized is pInput[0..nBytes-1]. A cursor
** used to incrementally tokenize this string is returned in
** *ppCursor.
*/
static int icuOpen(
sqlite3_tokenizer *pTokenizer, /* The tokenizer */
const char *zInput, /* Input string */
int nInput, /* Length of zInput in bytes */
sqlite3_tokenizer_cursor **ppCursor /* OUT: Tokenization cursor */
){
IcuTokenizer *p = (IcuTokenizer *)pTokenizer;
IcuCursor *pCsr;
const int32_t opt = U_FOLD_CASE_DEFAULT;
UErrorCode status = U_ZERO_ERROR;
int nChar;
UChar32 c;
int iInput = 0;
}
pCsr->pIter = ubrk_open(UBRK_WORD, p->zLocale, pCsr->aChar, iOut, &status);
if( !U_SUCCESS(status) ){
sqlite3_free(pCsr);
return SQLITE_ERROR;
}
pCsr->nChar = iOut;
ubrk_first(pCsr->pIter);
*ppCursor = (sqlite3_tokenizer_cursor *)pCsr;
return SQLITE_OK;
}
/*
** Close a tokenization cursor previously opened by a call to icuOpen().
*/
static int icuClose(sqlite3_tokenizer_cursor *pCursor){
IcuCursor *pCsr = (IcuCursor *)pCursor;
ubrk_close(pCsr->pIter);
sqlite3_free(pCsr->zBuffer);
sqlite3_free(pCsr);
return SQLITE_OK;
}
/*
** Extract the next token from a tokenization cursor.
*/
static int icuNext(
sqlite3_tokenizer_cursor *pCursor, /* Cursor returned by simpleOpen */
const char **ppToken, /* OUT: *ppToken is the token text */
int *pnBytes, /* OUT: Number of bytes in token */
int *piStartOffset, /* OUT: Starting offset of token */
int *piEndOffset, /* OUT: Ending offset of token */
int *piPosition /* OUT: Position integer of token */
){
IcuCursor *pCsr = (IcuCursor *)pCursor;
int iStart = 0;
int iEnd = 0;
**
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
*/
/*
** Structures used by the virtual table interface
*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;
/*
** CAPI3REF: Virtual Table Object
** KEYWORDS: sqlite3_module {virtual table module}
**
** This structure, sometimes called a "virtual table module",
** defines the implementation of a [virtual tables].
** This structure consists mostly of methods for the module.
**
int iVersion;
int (*xCreate)(sqlite3*, void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVTab, char**);
int (*xConnect)(sqlite3*, void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVTab, char**);
int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
int (*xDisconnect)(sqlite3_vtab *pVTab);
int (*xDestroy)(sqlite3_vtab *pVTab);
int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
int (*xClose)(sqlite3_vtab_cursor*);
int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
int argc, sqlite3_value **argv);
int (*xNext)(sqlite3_vtab_cursor*);
int (*xEof)(sqlite3_vtab_cursor*);
int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
int (*xBegin)(sqlite3_vtab *pVTab);
int (*xSync)(sqlite3_vtab *pVTab);
int (*xCommit)(sqlite3_vtab *pVTab);
int (*xRollback)(sqlite3_vtab *pVTab);
int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
void **ppArg);
int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
/* The methods above are in version 1 of the sqlite_module object. Those
*/
struct sqlite3_vtab {
const sqlite3_module *pModule; /* The module for this virtual table */
int nRef; /* NO LONGER USED */
char *zErrMsg; /* Error message from sqlite3_mprintf() */
/* Virtual table implementations will typically add additional fields */
};
/*
** CAPI3REF: Virtual Table Cursor Object
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
**
** Every [virtual table module] implementation uses a subclass of the
** following structure to describe cursors that point into the
** [virtual table] and are used
** to loop through the virtual table. Cursors are created using the
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
** by the [sqlite3_module.xClose | xClose] method. Cursors are used
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
** of the module. Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
sqlite3_vtab *pVtab; /* Virtual table of this cursor */
/* Virtual table implementations will typically add additional fields */
};
/*
** CAPI3REF: Declare The Schema Of A Virtual Table
**
** ^The [xCreate] and [xConnect] methods of a
** [virtual table module] call this interface
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
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