deb-goldedplus/goldlib/gall/glzh.cpp

//  This may look like C code, but it is really -*- C++ -*-

//  ------------------------------------------------------------------
//  The Goldware Library
//  Copyright (C) 2000 Alex. S. Aganichev
//  ------------------------------------------------------------------
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Library General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Library General Public License for more details.
//
//  You should have received a copy of the GNU Library General Public
//  License along with this program; if not, write to the Free
//  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
//  MA 02111-1307, USA
//  ------------------------------------------------------------------
//  $Id$
//  ------------------------------------------------------------------
//  Digital Dynamics conversion of 1988 LZH (LHarc) encoding functions
//  Based on Japanese version 29-NOV-1988
//  LZSS coded by Haruhiko Okumura
//  Adaptive Huffman Coding coded by Haruyasu Yoshizaki
//  ------------------------------------------------------------------

#include <cstring>
#include <gctype.h>
#include <gmemdbg.h>
#include <glzh.h>


//  ------------------------------------------------------------------
//  LZSS Parameters

#define LZH_N         4096    // Size of string buffer
#define LZH_F         60      // Size of look-ahead buffer
#define LZH_THRESHOLD 2
#define LZH_NIL       LZH_N   // End of tree's node

static char lzh_text_buf[LZH_N + LZH_F - 1];
static short int lzh_match_position, lzh_match_length, lzh_lson[LZH_N + 1], lzh_rson[LZH_N + 257], lzh_dad[LZH_N + 1];


//  ------------------------------------------------------------------
//  Initializing tree

static void glzh_init_tree(void) {
  short int  i;

  for(i = LZH_N + 1; i <= LZH_N + 256; i++)
    lzh_rson[i] = LZH_NIL; // root
  for(i = 0; i < LZH_N; i++)
    lzh_dad[i] = LZH_NIL;  // node
}


//  ------------------------------------------------------------------
//  Inserting node to the tree
//  Only used during encoding

static void glzh_insert_node(short int r) {
  short int i, p, cmp;
  char *key;
  unsigned c;

  cmp = 1;
  key = lzh_text_buf+r;
  p = LZH_N + 1 + key[0];
  lzh_rson[r] = lzh_lson[r] = LZH_NIL;
  lzh_match_length = 0;
  for(;;) {
    if(cmp >= 0) {
      if(lzh_rson[p] != LZH_NIL)
        p = lzh_rson[p];
      else {
        lzh_rson[p] = r;
        lzh_dad[r] = p;
        return;
      }
    } else {
      if(lzh_lson[p] != LZH_NIL)
        p = lzh_lson[p];
      else {
        lzh_lson[p] = r;
        lzh_dad[r] = p;
        return;
      }
    }
    for(i = 1; i < LZH_F; i++)
      if((cmp = key[i] - lzh_text_buf[p + i]) != 0)
        break;
    if(i > LZH_THRESHOLD) {
      if(i > lzh_match_length) {
        lzh_match_position = ((r - p) & (LZH_N - 1)) - 1;
        if((lzh_match_length = i) >= LZH_F)
          break;
      }
      if(i == lzh_match_length) {
        if((c = ((r - p) & (LZH_N - 1)) - 1) < lzh_match_position) {
          lzh_match_position = c;
	}
      }
    }
  }
  lzh_dad[r] = lzh_dad[p];
  lzh_lson[r] = lzh_lson[p];
  lzh_rson[r] = lzh_rson[p];
  lzh_dad[lzh_lson[p]] = r;
  lzh_dad[lzh_rson[p]] = r;
  if(lzh_rson[lzh_dad[p]] == p)
    lzh_rson[lzh_dad[p]] = r;
  else
    lzh_lson[lzh_dad[p]] = r;
  lzh_dad[p] = LZH_NIL; // remove p
}


//  ------------------------------------------------------------------
//  Deleting node from the tree

static void glzh_delete_node(short int p) {
  short int  q;

  if(lzh_dad[p] == LZH_NIL)
    return; // unregistered
  if(lzh_rson[p] == LZH_NIL)
    q = lzh_lson[p];
  else
    if(lzh_lson[p] == LZH_NIL)
      q = lzh_rson[p];
    else {
      q = lzh_lson[p];
      if(lzh_rson[q] != LZH_NIL) {
        do {
          q = lzh_rson[q];
        } while (lzh_rson[q] != LZH_NIL);
        lzh_rson[lzh_dad[q]] = lzh_lson[q];
        lzh_dad[lzh_lson[q]] = lzh_dad[q];
        lzh_lson[q] = lzh_lson[p];
        lzh_dad[lzh_lson[p]] = q;
      }
      lzh_rson[q] = lzh_rson[p];
      lzh_dad[lzh_rson[p]] = q;
    }
  lzh_dad[q] = lzh_dad[p];
  if(lzh_rson[lzh_dad[p]] == p)
    lzh_rson[lzh_dad[p]] = q;
  else
    lzh_lson[lzh_dad[p]] = q;
  lzh_dad[p] = LZH_NIL;
}


//  ------------------------------------------------------------------
//  Huffman coding parameters

// character code (= 0..LZH_N_CHAR-1)
#define LZH_N_CHAR (256 - LZH_THRESHOLD + LZH_F)
// Size of table
#define LZH_T      (LZH_N_CHAR * 2 - 1)
// root position
#define LZH_R      (LZH_T - 1)
// update when cumulative frequency reaches to this value
#define MAX_FREQ   0x8000

//  ------------------------------------------------------------------
//  Tables for encoding/decoding upper 6 bits of sliding dictionary pointer

//  ------------------------------------------------------------------
//  encoder table

static char lzh_p_len[64] = {
  0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
  0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08
};

static char lzh_p_code[64] = {
  0x00, 0x20, 0x30, 0x40, 0x50, 0x58, 0x60, 0x68,
  0x70, 0x78, 0x80, 0x88, 0x90, 0x94, 0x98, 0x9C,
  0xA0, 0xA4, 0xA8, 0xAC, 0xB0, 0xB4, 0xB8, 0xBC,
  0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE,
  0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC, 0xDE,
  0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE,
  0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
  0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
};


//  ------------------------------------------------------------------
//  decoder table

static char lzh_d_code[256] = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
  0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
  0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
  0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
  0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
  0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
  0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
  0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A,
  0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B,
  0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D,
  0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F, 0x0F, 0x0F,
  0x10, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x11,
  0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13,
  0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15,
  0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x17,
  0x18, 0x18, 0x19, 0x19, 0x1A, 0x1A, 0x1B, 0x1B,
  0x1C, 0x1C, 0x1D, 0x1D, 0x1E, 0x1E, 0x1F, 0x1F,
  0x20, 0x20, 0x21, 0x21, 0x22, 0x22, 0x23, 0x23,
  0x24, 0x24, 0x25, 0x25, 0x26, 0x26, 0x27, 0x27,
  0x28, 0x28, 0x29, 0x29, 0x2A, 0x2A, 0x2B, 0x2B,
  0x2C, 0x2C, 0x2D, 0x2D, 0x2E, 0x2E, 0x2F, 0x2F,
  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
  0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
};

static char lzh_d_len[256] = {
  0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
  0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
  0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
  0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
  0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
  0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
};


//  ------------------------------------------------------------------

static unsigned short lzh_freq[LZH_T + 1]; // cumulative freq table
static short int lzh_prnt[LZH_T + LZH_N_CHAR];
static short int lzh_son[LZH_T + 1];

static unsigned short lzh_getbuf = 0;
static char lzh_getlen = 0;


//  ------------------------------------------------------------------
//  get one bit

static int glzh_getbit(char *inbuf, long *incnt, long inlen) {
  short int i;

  while(lzh_getlen <= 8) {
    if((*incnt)>=inlen)
      i=0;
    else
      i=inbuf[(*incnt)++];
    lzh_getbuf |= i << (8 - lzh_getlen);
    lzh_getlen += 8;
  }
  i = lzh_getbuf;
  lzh_getbuf <<= 1;
  lzh_getlen--;
  return (i < 0);
}


//  ------------------------------------------------------------------
//  get a byte

static short int glzh_getbyte(char *inbuf, long *incnt, long inlen) {
  unsigned short i;

  while(lzh_getlen <= 8) {
    if((*incnt)>=inlen)
      i=0;
    else
      i=inbuf[(*incnt)++];
    lzh_getbuf |= i << (8 - lzh_getlen);
    lzh_getlen += 8;
  }
  i = lzh_getbuf;
  lzh_getbuf <<= 8;
  lzh_getlen -= 8;
  return i >> 8;
}


//  ------------------------------------------------------------------

static unsigned lzh_putbuf = 0;
static char lzh_putlen = 0;


//  ------------------------------------------------------------------
//  output c bits

static void glzh_putcode(short int l, unsigned short c, char *outbuf, long *outlen) {

  lzh_putbuf |= c >> lzh_putlen;
  if((lzh_putlen += l) >= 8) {
    outbuf[(*outlen)++]=(lzh_putbuf >> 8);
    if((lzh_putlen -= 8) >= 8) {
      outbuf[(*outlen)++]=lzh_putbuf;
      lzh_putlen -= 8;
      lzh_putbuf = c << (l - lzh_putlen);
    }
    else {
      lzh_putbuf <<= 8;
    }
  }
}


//  ------------------------------------------------------------------
//  initialize freq tree

static void glzh_start_huff() {
  short int i, j;

  lzh_getbuf = 0;
  lzh_getlen = 0;
  lzh_putbuf = 0;
  lzh_putlen = 0;

  for(i = 0; i < LZH_N_CHAR; i++) {
    lzh_freq[i] = 1;
    lzh_son[i] = i + LZH_T;
    lzh_prnt[i + LZH_T] = i;
  }
  i = 0; j = LZH_N_CHAR;
  while(j <= LZH_R) {
    lzh_freq[j] = lzh_freq[i] + lzh_freq[i + 1];
    lzh_son[j] = i;
    lzh_prnt[i] = lzh_prnt[i + 1] = j;
    i += 2; j++;
  }
  lzh_freq[LZH_T] = 0xffff;
  lzh_prnt[LZH_R] = 0;
}


//  ------------------------------------------------------------------
//  reconstruct freq tree

static void glzh_reconst() {
  short int i, j, k;
  unsigned short f, l;

  // halven cumulative freq for leaf nodes
  j = 0;
  for(i = 0; i < LZH_T; i++) {
    if(lzh_son[i] >= LZH_T) {
      lzh_freq[j] = (lzh_freq[i] + 1) / 2;
      lzh_son[j] = lzh_son[i];
      j++;
    }
  }
  // make a tree : first, connect children nodes
  for(i = 0, j = LZH_N_CHAR; j < LZH_T; i += 2, j++) {
    k = i + 1;
    f = lzh_freq[j] = lzh_freq[i] + lzh_freq[k];
    for(k = j - 1; f < lzh_freq[k]; k--);
    k++;
    l = (j - k) * 2;
		
    memmove(lzh_freq+k+1, lzh_freq+k, l);
    lzh_freq[k] = f;
    memmove(lzh_son+k+1, lzh_son+k, l);
    lzh_son[k] = i;
  }
  // connect parent nodes
  for(i = 0; i < LZH_T; i++) {
    if((k = lzh_son[i]) >= LZH_T)
      lzh_prnt[k] = i;
    else
      lzh_prnt[k] = lzh_prnt[k + 1] = i;
  }
}


//  ------------------------------------------------------------------
//  update freq tree

static void glzh_update(short int c)
{
  short int i, j, k, l;

  if (lzh_freq[LZH_R] == MAX_FREQ)
    glzh_reconst();
  c = lzh_prnt[c + LZH_T];
  do {
    k = ++lzh_freq[c];

    /* swap nodes to keep the tree freq-ordered */
    if(k > lzh_freq[l = c + 1]) {
      while(k > lzh_freq[++l]);
      l--;
      lzh_freq[c] = lzh_freq[l];
      lzh_freq[l] = k;

      i = lzh_son[c];
      lzh_prnt[i] = l;
      if(i < LZH_T)
        lzh_prnt[i + 1] = l;

      j = lzh_son[l];
      lzh_son[l] = i;

      lzh_prnt[j] = c;
      if(j < LZH_T)
        lzh_prnt[j + 1] = c;
      lzh_son[c] = j;

      c = l;
    }
  } while((c = lzh_prnt[c]) != 0); // do it until reaching the root
}


//  ------------------------------------------------------------------

static unsigned short lzh_code, lzh_len;


//  ------------------------------------------------------------------

static void glzh_encode_char(unsigned short c, char *outbuf, long *outlen) {
  unsigned short i;
  short int j, k;

  i = 0;
  j = 0;
  k = lzh_prnt[c + LZH_T];

  // search connections from leaf node to the root
  do {
    i >>= 1;
    // if node's address is odd, output 1
    // else output 0
    if(k & 1)
      i += 0x8000;
    j++;
  } while ((k = lzh_prnt[k]) != LZH_R);
  glzh_putcode(j, i, outbuf, outlen);
  lzh_code = i;
  lzh_len = j;
  glzh_update(c);
}


//  ------------------------------------------------------------------

static void glzh_encode_position(unsigned short c, char *outbuf, long *outlen) {
  unsigned short i;

  // output upper 6 bits with encoding
  i = c >> 6;
  glzh_putcode(lzh_p_len[i], (unsigned)lzh_p_code[i] << 8, outbuf, outlen);

  // output lower 6 bits directly
  glzh_putcode(6, (c & 0x3f) << 10, outbuf, outlen);
}


//  ------------------------------------------------------------------

static void glzh_encode_end(char *outbuf, long *outlen) {

  if(lzh_putlen)
    outbuf[(*outlen)++]=(lzh_putbuf >> 8);
}


//  ------------------------------------------------------------------

static short int glzh_decode_char(char *inbuf, long *incnt, long inlen) {
  unsigned short c;

  c = lzh_son[LZH_R];
  // start searching tree from the root to leaves.
  // choose node #(lzh_son[]) if input bit == 0
  // else choose #(lzh_son[]+1) (input bit == 1)
  while (c < LZH_T) {
    c += glzh_getbit(inbuf,incnt,inlen);
    c = lzh_son[c];
  }
  c -= LZH_T;
  glzh_update(c);
  return c;
}


//  ------------------------------------------------------------------

static short int glzh_decode_position(char *inbuf, long *incnt, long inlen) {
  unsigned short i, j, c;

  // decode upper 6 bits from given table
  i = glzh_getbyte(inbuf,incnt,inlen);
  c = (unsigned)lzh_d_code[i] << 6;
  j = lzh_d_len[i];
  // input lower 6 bits directly
  j -= 2;
  while(j--)
    i = (i << 1) + glzh_getbit(inbuf,incnt,inlen);
  return c | i & 0x3f;
}


//  ------------------------------------------------------------------
//  Encoding/Compressing: returns length of outbuf

long glzh_encode(char *inbuf, long inlen, char *outbuf) {
  short int  i, c, len, r, s, last_match_length;
  long incnt,outlen; // textsize=0;

  incnt=0;
  memcpy(outbuf,&inlen,sizeof(inlen));
  outlen=sizeof(inlen);
  if(not inlen) {
    return(outlen);
  }
  glzh_start_huff();
  glzh_init_tree();
  s = 0;
  r = LZH_N - LZH_F;
  for(i = s; i < r; i++)
    lzh_text_buf[i] = ' ';
  for(len = 0; len<LZH_F and incnt<inlen; len++)
    lzh_text_buf[r + len] = inbuf[incnt++];
  for(i = 1; i <= LZH_F; i++)
    glzh_insert_node(r - i);
  glzh_insert_node(r);
  do {
    if(lzh_match_length > len)
      lzh_match_length = len;
    if(lzh_match_length <= LZH_THRESHOLD) {
      lzh_match_length = 1;
      glzh_encode_char(lzh_text_buf[r],outbuf,&outlen);
    } else {
      glzh_encode_char(255 - LZH_THRESHOLD + lzh_match_length, outbuf, &outlen);
      glzh_encode_position(lzh_match_position, outbuf, &outlen);
    }
    last_match_length = lzh_match_length;
    for(i = 0; i<last_match_length and incnt<inlen; i++) {
      glzh_delete_node(s);
      c=inbuf[incnt++];
      lzh_text_buf[s] = c;
      if(s < LZH_F - 1)
	lzh_text_buf[s + LZH_N] = c;
      s = (s + 1) & (LZH_N - 1);
      r = (r + 1) & (LZH_N - 1);
      glzh_insert_node(r);
    }
    while(i++ < last_match_length) {
      glzh_delete_node(s);
      s = (s + 1) & (LZH_N - 1);
      r = (r + 1) & (LZH_N - 1);
      if(--len)
        glzh_insert_node(r);
    }
  } while(len > 0);
  glzh_encode_end(outbuf, &outlen);

  return(outlen);
}


//  ------------------------------------------------------------------
//  Decoding/Uncompressing: returns length of outbuf

long glzh_decode(char *inbuf, long inlen, char *outbuf) {
  short int  i, j, k, r, c;
  unsigned long int  count;
  long incnt,textsize;

  incnt=0;
  memcpy(&textsize, inbuf, sizeof(textsize));
  incnt+=sizeof(textsize);
  if(textsize == 0) {
    return(textsize);
  }
  glzh_start_huff();
  for(i = 0; i < LZH_N - LZH_F; i++)
    *(lzh_text_buf+i) = ' ';
  r = LZH_N - LZH_F;
  for(count = 0; count < textsize; ) {
    c = glzh_decode_char(inbuf,&incnt,inlen);
    if(c < 256) {
      outbuf[count]=c;
      *(lzh_text_buf+r) = c;
      r++;
      r &= (LZH_N - 1);
      count++;
    }
    else {
      i = (r - glzh_decode_position(inbuf,&incnt,inlen) - 1) & (LZH_N - 1);
      j = c - 255 + LZH_THRESHOLD;
      for (k = 0; k < j && count<textsize; k++) {
        c = lzh_text_buf[(i + k) & (LZH_N - 1)];
        outbuf[count]=c;
        *(lzh_text_buf+r) = c;
        r++;
        r &= (LZH_N - 1);
        count++;
      }
    }
  }

  return(count);
}


//  ------------------------------------------------------------------