652 lines
18 KiB
C++
652 lines
18 KiB
C++
// This may look like C code, but it is really -*- C++ -*-
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// ------------------------------------------------------------------
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// The Goldware Library
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// Copyright (C) 2000 Alex. S. Aganichev
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// ------------------------------------------------------------------
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Library General Public
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// License as published by the Free Software Foundation; either
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// version 2 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Library General Public License for more details.
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//
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// You should have received a copy of the GNU Library General Public
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// License along with this program; if not, write to the Free
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// Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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// MA 02111-1307, USA
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// ------------------------------------------------------------------
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// $Id$
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// ------------------------------------------------------------------
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// Digital Dynamics conversion of 1988 LZH (LHarc) encoding functions
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// Based on Japanese version 29-NOV-1988
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// LZSS coded by Haruhiko Okumura
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// Adaptive Huffman Coding coded by Haruyasu Yoshizaki
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// ------------------------------------------------------------------
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#include <cstring>
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#include <gctype.h>
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#include <gmemdbg.h>
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#include <glzh.h>
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// ------------------------------------------------------------------
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// LZSS Parameters
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#define LZH_N 4096 // Size of string buffer
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#define LZH_F 60 // Size of look-ahead buffer
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#define LZH_THRESHOLD 2
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#define LZH_NIL LZH_N // End of tree's node
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static char lzh_text_buf[LZH_N + LZH_F - 1];
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static short int lzh_match_position, lzh_match_length, lzh_lson[LZH_N + 1], lzh_rson[LZH_N + 257], lzh_dad[LZH_N + 1];
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// ------------------------------------------------------------------
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// Initializing tree
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static void glzh_init_tree(void) {
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short int i;
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for(i = LZH_N + 1; i <= LZH_N + 256; i++)
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lzh_rson[i] = LZH_NIL; // root
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for(i = 0; i < LZH_N; i++)
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lzh_dad[i] = LZH_NIL; // node
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}
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// ------------------------------------------------------------------
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// Inserting node to the tree
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// Only used during encoding
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static void glzh_insert_node(short int r) {
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short int i, p, cmp;
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char *key;
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unsigned c;
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cmp = 1;
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key = lzh_text_buf+r;
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p = LZH_N + 1 + key[0];
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lzh_rson[r] = lzh_lson[r] = LZH_NIL;
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lzh_match_length = 0;
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for(;;) {
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if(cmp >= 0) {
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if(lzh_rson[p] != LZH_NIL)
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p = lzh_rson[p];
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else {
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lzh_rson[p] = r;
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lzh_dad[r] = p;
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return;
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}
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} else {
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if(lzh_lson[p] != LZH_NIL)
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p = lzh_lson[p];
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else {
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lzh_lson[p] = r;
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lzh_dad[r] = p;
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return;
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}
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}
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for(i = 1; i < LZH_F; i++)
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if((cmp = key[i] - lzh_text_buf[p + i]) != 0)
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break;
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if(i > LZH_THRESHOLD) {
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if(i > lzh_match_length) {
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lzh_match_position = ((r - p) & (LZH_N - 1)) - 1;
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if((lzh_match_length = i) >= LZH_F)
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break;
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}
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if(i == lzh_match_length) {
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if((c = ((r - p) & (LZH_N - 1)) - 1) < lzh_match_position) {
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lzh_match_position = c;
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}
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}
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}
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}
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lzh_dad[r] = lzh_dad[p];
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lzh_lson[r] = lzh_lson[p];
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lzh_rson[r] = lzh_rson[p];
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lzh_dad[lzh_lson[p]] = r;
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lzh_dad[lzh_rson[p]] = r;
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if(lzh_rson[lzh_dad[p]] == p)
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lzh_rson[lzh_dad[p]] = r;
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else
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lzh_lson[lzh_dad[p]] = r;
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lzh_dad[p] = LZH_NIL; // remove p
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}
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// ------------------------------------------------------------------
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// Deleting node from the tree
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static void glzh_delete_node(short int p) {
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short int q;
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if(lzh_dad[p] == LZH_NIL)
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return; // unregistered
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if(lzh_rson[p] == LZH_NIL)
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q = lzh_lson[p];
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else
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if(lzh_lson[p] == LZH_NIL)
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q = lzh_rson[p];
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else {
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q = lzh_lson[p];
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if(lzh_rson[q] != LZH_NIL) {
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do {
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q = lzh_rson[q];
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} while (lzh_rson[q] != LZH_NIL);
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lzh_rson[lzh_dad[q]] = lzh_lson[q];
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lzh_dad[lzh_lson[q]] = lzh_dad[q];
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lzh_lson[q] = lzh_lson[p];
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lzh_dad[lzh_lson[p]] = q;
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}
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lzh_rson[q] = lzh_rson[p];
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lzh_dad[lzh_rson[p]] = q;
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}
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lzh_dad[q] = lzh_dad[p];
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if(lzh_rson[lzh_dad[p]] == p)
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lzh_rson[lzh_dad[p]] = q;
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else
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lzh_lson[lzh_dad[p]] = q;
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lzh_dad[p] = LZH_NIL;
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}
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// ------------------------------------------------------------------
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// Huffman coding parameters
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// character code (= 0..LZH_N_CHAR-1)
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#define LZH_N_CHAR (256 - LZH_THRESHOLD + LZH_F)
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// Size of table
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#define LZH_T (LZH_N_CHAR * 2 - 1)
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// root position
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#define LZH_R (LZH_T - 1)
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// update when cumulative frequency reaches to this value
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#define MAX_FREQ 0x8000
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// ------------------------------------------------------------------
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// Tables for encoding/decoding upper 6 bits of sliding dictionary pointer
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// ------------------------------------------------------------------
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// encoder table
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static char lzh_p_len[64] = {
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0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08
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};
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static char lzh_p_code[64] = {
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0x00, 0x20, 0x30, 0x40, 0x50, 0x58, 0x60, 0x68,
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0x70, 0x78, 0x80, 0x88, 0x90, 0x94, 0x98, 0x9C,
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0xA0, 0xA4, 0xA8, 0xAC, 0xB0, 0xB4, 0xB8, 0xBC,
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0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE,
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0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC, 0xDE,
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0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE,
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0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
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0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
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};
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// ------------------------------------------------------------------
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// decoder table
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static char lzh_d_code[256] = {
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
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0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
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0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
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0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
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0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A,
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0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B,
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0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D,
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0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F, 0x0F, 0x0F,
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0x10, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x11,
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0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13,
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0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15,
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0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x17,
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0x18, 0x18, 0x19, 0x19, 0x1A, 0x1A, 0x1B, 0x1B,
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0x1C, 0x1C, 0x1D, 0x1D, 0x1E, 0x1E, 0x1F, 0x1F,
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0x20, 0x20, 0x21, 0x21, 0x22, 0x22, 0x23, 0x23,
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0x24, 0x24, 0x25, 0x25, 0x26, 0x26, 0x27, 0x27,
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0x28, 0x28, 0x29, 0x29, 0x2A, 0x2A, 0x2B, 0x2B,
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0x2C, 0x2C, 0x2D, 0x2D, 0x2E, 0x2E, 0x2F, 0x2F,
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0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
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0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
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};
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static char lzh_d_len[256] = {
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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};
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// ------------------------------------------------------------------
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static unsigned short lzh_freq[LZH_T + 1]; // cumulative freq table
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static short int lzh_prnt[LZH_T + LZH_N_CHAR];
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static short int lzh_son[LZH_T + 1];
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static unsigned short lzh_getbuf = 0;
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static char lzh_getlen = 0;
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// ------------------------------------------------------------------
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// get one bit
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static int glzh_getbit(char *inbuf, long *incnt, long inlen) {
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short int i;
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while(lzh_getlen <= 8) {
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if((*incnt)>=inlen)
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i=0;
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else
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i=inbuf[(*incnt)++];
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lzh_getbuf |= i << (8 - lzh_getlen);
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lzh_getlen += 8;
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}
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i = lzh_getbuf;
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lzh_getbuf <<= 1;
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lzh_getlen--;
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return (i < 0);
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}
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// ------------------------------------------------------------------
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// get a byte
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static short int glzh_getbyte(char *inbuf, long *incnt, long inlen) {
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unsigned short i;
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while(lzh_getlen <= 8) {
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if((*incnt)>=inlen)
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i=0;
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else
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i=inbuf[(*incnt)++];
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lzh_getbuf |= i << (8 - lzh_getlen);
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lzh_getlen += 8;
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}
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i = lzh_getbuf;
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lzh_getbuf <<= 8;
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lzh_getlen -= 8;
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return i >> 8;
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}
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// ------------------------------------------------------------------
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static unsigned lzh_putbuf = 0;
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static char lzh_putlen = 0;
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// ------------------------------------------------------------------
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// output c bits
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static void glzh_putcode(short int l, unsigned short c, char *outbuf, long *outlen) {
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lzh_putbuf |= c >> lzh_putlen;
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if((lzh_putlen += l) >= 8) {
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outbuf[(*outlen)++]=(lzh_putbuf >> 8);
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if((lzh_putlen -= 8) >= 8) {
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outbuf[(*outlen)++]=lzh_putbuf;
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lzh_putlen -= 8;
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lzh_putbuf = c << (l - lzh_putlen);
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}
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else {
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lzh_putbuf <<= 8;
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}
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}
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}
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// ------------------------------------------------------------------
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// initialize freq tree
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static void glzh_start_huff() {
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short int i, j;
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lzh_getbuf = 0;
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lzh_getlen = 0;
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lzh_putbuf = 0;
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lzh_putlen = 0;
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for(i = 0; i < LZH_N_CHAR; i++) {
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lzh_freq[i] = 1;
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lzh_son[i] = i + LZH_T;
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lzh_prnt[i + LZH_T] = i;
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}
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i = 0; j = LZH_N_CHAR;
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while(j <= LZH_R) {
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lzh_freq[j] = lzh_freq[i] + lzh_freq[i + 1];
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lzh_son[j] = i;
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lzh_prnt[i] = lzh_prnt[i + 1] = j;
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i += 2; j++;
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}
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lzh_freq[LZH_T] = 0xffff;
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lzh_prnt[LZH_R] = 0;
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}
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// ------------------------------------------------------------------
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// reconstruct freq tree
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static void glzh_reconst() {
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short int i, j, k;
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unsigned short f, l;
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// halven cumulative freq for leaf nodes
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j = 0;
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for(i = 0; i < LZH_T; i++) {
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if(lzh_son[i] >= LZH_T) {
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lzh_freq[j] = (lzh_freq[i] + 1) / 2;
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lzh_son[j] = lzh_son[i];
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j++;
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}
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}
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// make a tree : first, connect children nodes
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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);
|
|
}
|
|
|
|
|
|
// ------------------------------------------------------------------
|