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lib/Archive/Lha.xs  view on Meta::CPAN

/*
  XS for Archive::Lha

  This XS is, though largely modified, based on LHa for UNIX.
  See lib/Archive/Lha.pm for Authors/Copyright/License information.
*/
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"
#include "Lha.h"
#include <time.h>

/*
  these are not from LHa for UNIX
*/

void
destroy_stash(LhaStash * stash)
{
  Safefree(stash->tree->left);
  Safefree(stash->tree->right);
  Safefree(stash->tree);
  Safefree(stash->pt->table);
  Safefree(stash->pt->length);
  Safefree(stash->pt);
  Safefree(stash->c->table);
  Safefree(stash->c->length);
  Safefree(stash->c);
  Safefree(stash->bit);
  Safefree(stash->queue);
  Safefree(stash);
}

void
safe_croak(LhaStash * stash, char * dying_message)
{
  destroy_stash(stash);
  croak("%s", dying_message);
}

void
output(LhaStash * stash, unsigned char * queue, int len)
{
  dSP;
  ENTER;
  SAVETMPS;
  PUSHMARK(SP);
  XPUSHs(sv_2mortal(newSVpv(queue, len)));
  PUTBACK;
  call_sv(stash->write, G_VOID);
  SPAGAIN;
  PUTBACK;
  FREETMPS;
  LEAVE;
}

void
input(LhaStash * stash, int len)
{
  int n;
  SV *sv;
  STRLEN got;
  const char *ptr;
  dSP;
  ENTER;
  SAVETMPS;
  PUSHMARK(SP);
  XPUSHs(sv_2mortal(newSViv(len)));
  PUTBACK;
  n = call_sv(stash->read, G_SCALAR);
  SPAGAIN;
  if (n != 1)
    safe_croak(stash, "There's something wrong in 'read' callback");
  sv  = POPs;
  ptr = SvPVbyte(sv, got);
  Copy(ptr, stash->bit->readbuf, (STRLEN)len <= got ? (STRLEN)len : got, unsigned char);
  PUTBACK;
  FREETMPS;
  LEAVE;
}

/*
  modified from LHa for UNIX: bitio.c ver 1.14
    original authors:
      Source All chagned       1995.01.14  N.Watazaki
      Separated from crcio.c   2002.10.26  Koji Arai
*/

unsigned short
shiftbits(LhaBitstream * bit, unsigned char n)
{
  return (bit->value << n)
       + (bit->buf >> (char_bit - n));
}

void
fillbuf(LhaStash * stash, unsigned char n)
{
  unsigned short len;
  LhaBitstream * bit = stash->bit;
  while (n > bit->pos) {
    n -= bit->pos;
    bit->value = shiftbits(bit, bit->pos);
    if (stash->encoded_size > 0) {
      if (bit->readpos == 0) {
        if (stash->encoded_size > readbuf_size)
          len = readbuf_size;
        else
          len = stash->encoded_size;
        input(stash, len);
      }
      bit->buf = bit->readbuf[bit->readpos++];
      if (bit->readpos == readbuf_size)
        bit->readpos = 0;
      stash->encoded_size--;
    }
    else
      bit->buf = 0;
    bit->pos = char_bit;
  }
  bit->pos -= n;
  bit->value = shiftbits(bit, n);
  bit->buf <<= n;
}

unsigned short
peekbits(LhaStash * stash, unsigned char n)
{
  return (stash->bit->value >> (ushort_bit - n));
}

unsigned short
getbits(LhaStash * stash, unsigned char n)
{
  unsigned short bits = peekbits(stash, n);
  fillbuf(stash, n);
  return bits;

lib/Archive/Lha.xs  view on Meta::CPAN

    if ( !hash_exists(self, "read") )
      croak("'read' callback is missing");
    if ( !hash_exists(self, "write") )
      croak("'write' callback is missing");

    dicsize  = self_uint("DICSIZE");
    dicsize1 = dicsize - 1;

    Newxz(queue, dicsize, unsigned char);
    Newxz(stash, 1, LhaStash);

    stash->queue = queue;

    stash->read          = self_sv("read");
    stash->write         = self_sv("write");
    stash->original_size = self_uint("original_size");
    stash->encoded_size  = self_uint("encoded_size");

    init_tables(self, stash);
    init_bitstream(stash);

    adjust = (1u << uchar_bit) - self_uchar("THRESHOLD");
    crc16  = 0;
    loc    = 0;
    total  = 0;
    while ( total < stash->original_size ) {
      c = decode_c(stash);
      if (c <= uchar_max) {
        queue[loc++] = c;
        if (loc == dicsize) {
          output(stash, queue, dicsize);
          crc16 = calc_crc16(crc16, queue, dicsize);
          loc = 0;
        }
        total++;
      }
      else {
        matchlen = c - adjust;
        matchoff = decode_p(stash) + 1;
        matchpos = (loc - matchoff) & dicsize1;
        total += matchlen;
        for(i = 0; i < matchlen; i++) {
          queue[loc++] = queue[(matchpos + i) & dicsize1];
          if (loc == dicsize) {
            output(stash, queue, dicsize);
            crc16 = calc_crc16(crc16, queue, dicsize);
            loc = 0;
          }
        }
      }
    }
    if (loc) {
      output(stash, queue, loc);
      crc16 = calc_crc16(crc16, queue, loc);
    }

    destroy_stash(stash);

    RETVAL = crc16;

  OUTPUT:
    RETVAL

MODULE = Archive::Lha PACKAGE = Archive::Lha::CRC PREFIX = xs_

PROTOTYPES: DISABLE

#/* this is not from LHa for UNIX */

unsigned short
xs_update(unsigned short crc, SV * str, STRLEN len)
  CODE:
    RETVAL = calc_crc16(crc, SvPV(str, len), len);

  OUTPUT:
    RETVAL

MODULE = Archive::Lha PACKAGE = Archive::Lha::Header::Utils PREFIX = xs_

PROTOTYPES: DISABLE

unsigned char
xs_checksum(SV * buf, STRLEN offset)
  CODE:
    STRLEN len;
    unsigned char * s = (unsigned char *) SvPV(buf, len);
    unsigned char sum = 0;
    STRLEN i;
    for (i = offset; i < len; i++)
      sum += s[i];
    RETVAL = sum;
  OUTPUT:
    RETVAL

IV
xs_dostime2utime(U32 v)
  CODE:
    struct tm t;
    time_t result;
    if (v == 0) {
      RETVAL = 0;
    } else {
      t.tm_sec   = (v & 0x1F) * 2;
      t.tm_min   = (v >>  5) & 0x3F;
      t.tm_hour  = (v >> 11) & 0x1F;
      t.tm_mday  = (v >> 16) & 0x1F;
      t.tm_mon   = ((v >> 21) & 0x0F) - 1;
      t.tm_year  = ((v >> 25) & 0x7F) + 80;
      t.tm_isdst = -1;
      result = mktime(&t);
      RETVAL = (result == (time_t)-1) ? 0 : (IV)result;
    }
  OUTPUT:
    RETVAL

MODULE = Archive::Lha PACKAGE = Archive::Lha PREFIX = xs_

PROTOTYPES: DISABLE