// 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);
}
// ------------------------------------------------------------------