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lib/WAIT/Table.pm  view on Meta::CPAN

sub create_inverted_index {
  my $self  = shift;
  my %parm  = @_;

  croak "No attribute specified" unless $parm{attribute};
  croak "No pipeline specified"  unless $parm{pipeline};

  $parm{predicate} ||= $parm{pipeline}->[-1];

  croak "Cannot create index for table aready populated"
    if $self->{nextk} > 1;

  require WAIT::InvertedIndex;

  # backward compatibility stuff
  my %opt = %parm;
  for (qw(attribute pipeline predicate)) {
    delete $opt{$_};
  }

  my $name = join '_', ($parm{attribute}, @{$parm{pipeline}});
  my $idx = new WAIT::InvertedIndex(file   => $self->{file}.'/'.$name,
                                    filter => [@{$parm{pipeline}}], # clone
                                    name   => $name,
                                    attr   => $parm{attribute},
                                    %opt, # backward compatibility stuff
                                   );
  # We will have to use $parm{predicate} here
  push @{$self->{inverted}->{$parm{attribute}}}, $idx;
}

sub dir {
  $_[0]->{file};
}

=head2 C<$tb-E<gt>layout>

Returns the reference to the associated parser object.

=cut

sub layout { $_[0]->{layout} }

=head2 C<$tb-E<gt>fields>

Returns the array of attribute names.

=cut


sub fields { keys %{$_[0]->{inverted}}}

=head2 C<$tb-E<gt>drop>

Must be called via C<WAIT::Database::drop_table>

=cut

sub drop {
  my $self = shift;
  if ((caller)[0] eq 'WAIT::Database') { # database knows about this
    $self->close;               # just make sure
    my $file = $self->{file};

    for (values %{$self->{indexes}}) {
      $_->drop;
    }
    unlink "$file/records";
    # $self->unlock;
    ! (!-e $file or rmdir $file);
  } else {
    croak ref($self)."::drop called directly";
  }
}

sub mrequire ($) {
  my $module = shift;

  $module =~ s{::}{/}g;
  $module .= '.pm';
  require $module;
}

sub open {
  my $self = shift;
  my $file = $self->{file} . '/records';

  mrequire ref($self);           # that's tricky eh?
  if (defined $self->{'layout'}) {
    mrequire ref($self->{'layout'});
  }
  if (defined $self->{'access'}) {
    mrequire ref($self->{'access'});
  }
  if (exists $self->{indexes}) {
    require WAIT::Index;
    for (values %{$self->{indexes}}) {
      $_->{mode} = $self->{mode};
    }
  }
  if (exists $self->{inverted}) {
    my ($att, $idx);
    for $att (keys %{$self->{inverted}}) {
      for $idx (@{$self->{inverted}->{$att}}) {
        $idx->{mode} = $self->{mode};
      }
    }
    require WAIT::InvertedIndex;
  }
  unless (defined $self->{dbh}) {
    if ($USE_RECNO) {
      $self->{dbh} = tie(@{$self->{db}}, 'DB_File', $file,
                         $self->{mode}, 0664, $DB_RECNO);
    } else {
      $self->{dbh} =
        tie(%{$self->{db}}, 'DB_File', $file,
                         $self->{mode}, 0664, $DB_BTREE);
    }
  }

  # Locking