annotate zlib/trees.c @ 1965:3a46ff899fa6

More correct implementation of byte printing in builtin debugger. Fix GDB debugger to use helper in backend.c for reading bytes
author Michael Pavone <pavone@retrodev.com>
date Sun, 03 May 2020 23:28:42 -0700
parents 00d788dac91a
children
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1 /* trees.c -- output deflated data using Huffman coding
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2 * Copyright (C) 1995-2017 Jean-loup Gailly
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3 * detect_data_type() function provided freely by Cosmin Truta, 2006
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4 * For conditions of distribution and use, see copyright notice in zlib.h
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5 */
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6
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7 /*
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8 * ALGORITHM
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9 *
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10 * The "deflation" process uses several Huffman trees. The more
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11 * common source values are represented by shorter bit sequences.
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12 *
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13 * Each code tree is stored in a compressed form which is itself
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14 * a Huffman encoding of the lengths of all the code strings (in
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15 * ascending order by source values). The actual code strings are
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16 * reconstructed from the lengths in the inflate process, as described
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17 * in the deflate specification.
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18 *
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19 * REFERENCES
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20 *
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21 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
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22 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
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23 *
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24 * Storer, James A.
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25 * Data Compression: Methods and Theory, pp. 49-50.
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26 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
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27 *
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28 * Sedgewick, R.
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29 * Algorithms, p290.
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30 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
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31 */
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32
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33 /* @(#) $Id$ */
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34
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35 /* #define GEN_TREES_H */
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36
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37 #include "deflate.h"
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38
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39 #ifdef ZLIB_DEBUG
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40 # include <ctype.h>
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41 #endif
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42
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43 /* ===========================================================================
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44 * Constants
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45 */
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46
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47 #define MAX_BL_BITS 7
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48 /* Bit length codes must not exceed MAX_BL_BITS bits */
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49
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50 #define END_BLOCK 256
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51 /* end of block literal code */
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52
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53 #define REP_3_6 16
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54 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
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55
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56 #define REPZ_3_10 17
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57 /* repeat a zero length 3-10 times (3 bits of repeat count) */
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58
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59 #define REPZ_11_138 18
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60 /* repeat a zero length 11-138 times (7 bits of repeat count) */
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61
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62 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
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63 = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
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64
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65 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
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66 = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
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67
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68 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
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69 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
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70
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71 local const uch bl_order[BL_CODES]
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72 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
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73 /* The lengths of the bit length codes are sent in order of decreasing
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74 * probability, to avoid transmitting the lengths for unused bit length codes.
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75 */
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76
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77 /* ===========================================================================
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78 * Local data. These are initialized only once.
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79 */
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80
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81 #define DIST_CODE_LEN 512 /* see definition of array dist_code below */
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82
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83 #if defined(GEN_TREES_H) || !defined(STDC)
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84 /* non ANSI compilers may not accept trees.h */
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85
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86 local ct_data static_ltree[L_CODES+2];
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87 /* The static literal tree. Since the bit lengths are imposed, there is no
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88 * need for the L_CODES extra codes used during heap construction. However
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89 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
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90 * below).
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91 */
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92
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93 local ct_data static_dtree[D_CODES];
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94 /* The static distance tree. (Actually a trivial tree since all codes use
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95 * 5 bits.)
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96 */
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97
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98 uch _dist_code[DIST_CODE_LEN];
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99 /* Distance codes. The first 256 values correspond to the distances
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100 * 3 .. 258, the last 256 values correspond to the top 8 bits of
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101 * the 15 bit distances.
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102 */
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103
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104 uch _length_code[MAX_MATCH-MIN_MATCH+1];
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105 /* length code for each normalized match length (0 == MIN_MATCH) */
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106
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107 local int base_length[LENGTH_CODES];
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108 /* First normalized length for each code (0 = MIN_MATCH) */
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109
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110 local int base_dist[D_CODES];
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111 /* First normalized distance for each code (0 = distance of 1) */
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112
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113 #else
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114 # include "trees.h"
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115 #endif /* GEN_TREES_H */
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116
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117 struct static_tree_desc_s {
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118 const ct_data *static_tree; /* static tree or NULL */
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119 const intf *extra_bits; /* extra bits for each code or NULL */
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120 int extra_base; /* base index for extra_bits */
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121 int elems; /* max number of elements in the tree */
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122 int max_length; /* max bit length for the codes */
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123 };
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124
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125 local const static_tree_desc static_l_desc =
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126 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
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127
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128 local const static_tree_desc static_d_desc =
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129 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
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130
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131 local const static_tree_desc static_bl_desc =
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132 {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
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133
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134 /* ===========================================================================
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135 * Local (static) routines in this file.
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136 */
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137
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138 local void tr_static_init OF((void));
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139 local void init_block OF((deflate_state *s));
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140 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
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141 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
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142 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
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143 local void build_tree OF((deflate_state *s, tree_desc *desc));
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144 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
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diff changeset
145 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
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diff changeset
146 local int build_bl_tree OF((deflate_state *s));
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diff changeset
147 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
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diff changeset
148 int blcodes));
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diff changeset
149 local void compress_block OF((deflate_state *s, const ct_data *ltree,
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diff changeset
150 const ct_data *dtree));
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diff changeset
151 local int detect_data_type OF((deflate_state *s));
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diff changeset
152 local unsigned bi_reverse OF((unsigned value, int length));
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diff changeset
153 local void bi_windup OF((deflate_state *s));
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diff changeset
154 local void bi_flush OF((deflate_state *s));
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155
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diff changeset
156 #ifdef GEN_TREES_H
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157 local void gen_trees_header OF((void));
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158 #endif
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159
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diff changeset
160 #ifndef ZLIB_DEBUG
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161 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
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162 /* Send a code of the given tree. c and tree must not have side effects */
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163
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164 #else /* !ZLIB_DEBUG */
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165 # define send_code(s, c, tree) \
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166 { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
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167 send_bits(s, tree[c].Code, tree[c].Len); }
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168 #endif
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169
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diff changeset
170 /* ===========================================================================
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171 * Output a short LSB first on the stream.
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172 * IN assertion: there is enough room in pendingBuf.
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173 */
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174 #define put_short(s, w) { \
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175 put_byte(s, (uch)((w) & 0xff)); \
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176 put_byte(s, (uch)((ush)(w) >> 8)); \
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177 }
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178
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179 /* ===========================================================================
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180 * Send a value on a given number of bits.
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181 * IN assertion: length <= 16 and value fits in length bits.
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182 */
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183 #ifdef ZLIB_DEBUG
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184 local void send_bits OF((deflate_state *s, int value, int length));
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185
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186 local void send_bits(s, value, length)
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187 deflate_state *s;
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188 int value; /* value to send */
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189 int length; /* number of bits */
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190 {
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191 Tracevv((stderr," l %2d v %4x ", length, value));
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192 Assert(length > 0 && length <= 15, "invalid length");
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193 s->bits_sent += (ulg)length;
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194
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diff changeset
195 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
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196 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
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197 * unused bits in value.
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198 */
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199 if (s->bi_valid > (int)Buf_size - length) {
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200 s->bi_buf |= (ush)value << s->bi_valid;
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201 put_short(s, s->bi_buf);
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202 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
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203 s->bi_valid += length - Buf_size;
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diff changeset
204 } else {
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205 s->bi_buf |= (ush)value << s->bi_valid;
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206 s->bi_valid += length;
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207 }
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208 }
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diff changeset
209 #else /* !ZLIB_DEBUG */
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210
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diff changeset
211 #define send_bits(s, value, length) \
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212 { int len = length;\
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213 if (s->bi_valid > (int)Buf_size - len) {\
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214 int val = (int)value;\
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215 s->bi_buf |= (ush)val << s->bi_valid;\
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216 put_short(s, s->bi_buf);\
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diff changeset
217 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
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218 s->bi_valid += len - Buf_size;\
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219 } else {\
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220 s->bi_buf |= (ush)(value) << s->bi_valid;\
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221 s->bi_valid += len;\
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222 }\
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223 }
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diff changeset
224 #endif /* ZLIB_DEBUG */
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225
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226
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227 /* the arguments must not have side effects */
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228
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229 /* ===========================================================================
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230 * Initialize the various 'constant' tables.
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diff changeset
231 */
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232 local void tr_static_init()
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233 {
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234 #if defined(GEN_TREES_H) || !defined(STDC)
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235 static int static_init_done = 0;
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236 int n; /* iterates over tree elements */
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237 int bits; /* bit counter */
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238 int length; /* length value */
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239 int code; /* code value */
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240 int dist; /* distance index */
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diff changeset
241 ush bl_count[MAX_BITS+1];
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diff changeset
242 /* number of codes at each bit length for an optimal tree */
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diff changeset
243
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244 if (static_init_done) return;
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diff changeset
245
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diff changeset
246 /* For some embedded targets, global variables are not initialized: */
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diff changeset
247 #ifdef NO_INIT_GLOBAL_POINTERS
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248 static_l_desc.static_tree = static_ltree;
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249 static_l_desc.extra_bits = extra_lbits;
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250 static_d_desc.static_tree = static_dtree;
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diff changeset
251 static_d_desc.extra_bits = extra_dbits;
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diff changeset
252 static_bl_desc.extra_bits = extra_blbits;
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diff changeset
253 #endif
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254
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diff changeset
255 /* Initialize the mapping length (0..255) -> length code (0..28) */
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diff changeset
256 length = 0;
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diff changeset
257 for (code = 0; code < LENGTH_CODES-1; code++) {
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diff changeset
258 base_length[code] = length;
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diff changeset
259 for (n = 0; n < (1<<extra_lbits[code]); n++) {
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260 _length_code[length++] = (uch)code;
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diff changeset
261 }
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diff changeset
262 }
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diff changeset
263 Assert (length == 256, "tr_static_init: length != 256");
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diff changeset
264 /* Note that the length 255 (match length 258) can be represented
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diff changeset
265 * in two different ways: code 284 + 5 bits or code 285, so we
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diff changeset
266 * overwrite length_code[255] to use the best encoding:
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diff changeset
267 */
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268 _length_code[length-1] = (uch)code;
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269
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diff changeset
270 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
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diff changeset
271 dist = 0;
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diff changeset
272 for (code = 0 ; code < 16; code++) {
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diff changeset
273 base_dist[code] = dist;
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diff changeset
274 for (n = 0; n < (1<<extra_dbits[code]); n++) {
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diff changeset
275 _dist_code[dist++] = (uch)code;
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276 }
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277 }
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diff changeset
278 Assert (dist == 256, "tr_static_init: dist != 256");
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diff changeset
279 dist >>= 7; /* from now on, all distances are divided by 128 */
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diff changeset
280 for ( ; code < D_CODES; code++) {
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diff changeset
281 base_dist[code] = dist << 7;
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diff changeset
282 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
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diff changeset
283 _dist_code[256 + dist++] = (uch)code;
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diff changeset
284 }
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parents:
diff changeset
285 }
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parents:
diff changeset
286 Assert (dist == 256, "tr_static_init: 256+dist != 512");
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parents:
diff changeset
287
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parents:
diff changeset
288 /* Construct the codes of the static literal tree */
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parents:
diff changeset
289 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
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parents:
diff changeset
290 n = 0;
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parents:
diff changeset
291 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
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parents:
diff changeset
292 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
293 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
294 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
00d788dac91a Added support for reading gzipped ROMs
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diff changeset
295 /* Codes 286 and 287 do not exist, but we must include them in the
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
296 * tree construction to get a canonical Huffman tree (longest code
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parents:
diff changeset
297 * all ones)
00d788dac91a Added support for reading gzipped ROMs
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diff changeset
298 */
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diff changeset
299 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
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diff changeset
300
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parents:
diff changeset
301 /* The static distance tree is trivial: */
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parents:
diff changeset
302 for (n = 0; n < D_CODES; n++) {
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parents:
diff changeset
303 static_dtree[n].Len = 5;
00d788dac91a Added support for reading gzipped ROMs
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diff changeset
304 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
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parents:
diff changeset
305 }
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diff changeset
306 static_init_done = 1;
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diff changeset
307
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parents:
diff changeset
308 # ifdef GEN_TREES_H
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diff changeset
309 gen_trees_header();
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diff changeset
310 # endif
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diff changeset
311 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
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diff changeset
312 }
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diff changeset
313
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parents:
diff changeset
314 /* ===========================================================================
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diff changeset
315 * Genererate the file trees.h describing the static trees.
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parents:
diff changeset
316 */
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parents:
diff changeset
317 #ifdef GEN_TREES_H
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diff changeset
318 # ifndef ZLIB_DEBUG
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diff changeset
319 # include <stdio.h>
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diff changeset
320 # endif
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diff changeset
321
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parents:
diff changeset
322 # define SEPARATOR(i, last, width) \
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parents:
diff changeset
323 ((i) == (last)? "\n};\n\n" : \
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
324 ((i) % (width) == (width)-1 ? ",\n" : ", "))
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
325
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parents:
diff changeset
326 void gen_trees_header()
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parents:
diff changeset
327 {
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diff changeset
328 FILE *header = fopen("trees.h", "w");
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diff changeset
329 int i;
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parents:
diff changeset
330
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
331 Assert (header != NULL, "Can't open trees.h");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
332 fprintf(header,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
333 "/* header created automatically with -DGEN_TREES_H */\n\n");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
334
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
335 fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
336 for (i = 0; i < L_CODES+2; i++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
337 fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
338 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
339 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
340
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
341 fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
342 for (i = 0; i < D_CODES; i++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
343 fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
344 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
345 }
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
346
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
347 fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
348 for (i = 0; i < DIST_CODE_LEN; i++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
349 fprintf(header, "%2u%s", _dist_code[i],
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
350 SEPARATOR(i, DIST_CODE_LEN-1, 20));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
351 }
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
352
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
353 fprintf(header,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
354 "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
355 for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
356 fprintf(header, "%2u%s", _length_code[i],
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
357 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
358 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
359
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
360 fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
361 for (i = 0; i < LENGTH_CODES; i++) {
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
362 fprintf(header, "%1u%s", base_length[i],
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
363 SEPARATOR(i, LENGTH_CODES-1, 20));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
364 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
365
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
366 fprintf(header, "local const int base_dist[D_CODES] = {\n");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
367 for (i = 0; i < D_CODES; i++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
368 fprintf(header, "%5u%s", base_dist[i],
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
369 SEPARATOR(i, D_CODES-1, 10));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
370 }
00d788dac91a Added support for reading gzipped ROMs
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parents:
diff changeset
371
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
372 fclose(header);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
373 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
374 #endif /* GEN_TREES_H */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
375
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
376 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
377 * Initialize the tree data structures for a new zlib stream.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
378 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
379 void ZLIB_INTERNAL _tr_init(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
380 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
381 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
382 tr_static_init();
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
383
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
384 s->l_desc.dyn_tree = s->dyn_ltree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
385 s->l_desc.stat_desc = &static_l_desc;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
386
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
387 s->d_desc.dyn_tree = s->dyn_dtree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
388 s->d_desc.stat_desc = &static_d_desc;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
389
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
390 s->bl_desc.dyn_tree = s->bl_tree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
391 s->bl_desc.stat_desc = &static_bl_desc;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
392
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
393 s->bi_buf = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
394 s->bi_valid = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
395 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
396 s->compressed_len = 0L;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
397 s->bits_sent = 0L;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
398 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
399
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
400 /* Initialize the first block of the first file: */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
401 init_block(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
402 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
403
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
404 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
405 * Initialize a new block.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
406 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
407 local void init_block(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
408 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
409 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
410 int n; /* iterates over tree elements */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
411
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
412 /* Initialize the trees. */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
413 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
414 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
415 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
416
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
417 s->dyn_ltree[END_BLOCK].Freq = 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
418 s->opt_len = s->static_len = 0L;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
419 s->last_lit = s->matches = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
420 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
421
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
422 #define SMALLEST 1
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
423 /* Index within the heap array of least frequent node in the Huffman tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
424
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
425
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
426 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
427 * Remove the smallest element from the heap and recreate the heap with
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
428 * one less element. Updates heap and heap_len.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
429 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
430 #define pqremove(s, tree, top) \
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
431 {\
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
432 top = s->heap[SMALLEST]; \
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
433 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
434 pqdownheap(s, tree, SMALLEST); \
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
435 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
436
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
437 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
438 * Compares to subtrees, using the tree depth as tie breaker when
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
439 * the subtrees have equal frequency. This minimizes the worst case length.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
440 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
441 #define smaller(tree, n, m, depth) \
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
442 (tree[n].Freq < tree[m].Freq || \
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
443 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
444
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
445 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
446 * Restore the heap property by moving down the tree starting at node k,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
447 * exchanging a node with the smallest of its two sons if necessary, stopping
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
448 * when the heap property is re-established (each father smaller than its
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
449 * two sons).
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
450 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
451 local void pqdownheap(s, tree, k)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
452 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
453 ct_data *tree; /* the tree to restore */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
454 int k; /* node to move down */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
455 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
456 int v = s->heap[k];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
457 int j = k << 1; /* left son of k */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
458 while (j <= s->heap_len) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
459 /* Set j to the smallest of the two sons: */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
460 if (j < s->heap_len &&
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
461 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
462 j++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
463 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
464 /* Exit if v is smaller than both sons */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
465 if (smaller(tree, v, s->heap[j], s->depth)) break;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
466
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
467 /* Exchange v with the smallest son */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
468 s->heap[k] = s->heap[j]; k = j;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
469
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
470 /* And continue down the tree, setting j to the left son of k */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
471 j <<= 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
472 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
473 s->heap[k] = v;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
474 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
475
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
476 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
477 * Compute the optimal bit lengths for a tree and update the total bit length
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
478 * for the current block.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
479 * IN assertion: the fields freq and dad are set, heap[heap_max] and
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
480 * above are the tree nodes sorted by increasing frequency.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
481 * OUT assertions: the field len is set to the optimal bit length, the
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
482 * array bl_count contains the frequencies for each bit length.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
483 * The length opt_len is updated; static_len is also updated if stree is
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
484 * not null.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
485 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
486 local void gen_bitlen(s, desc)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
487 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
488 tree_desc *desc; /* the tree descriptor */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
489 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
490 ct_data *tree = desc->dyn_tree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
491 int max_code = desc->max_code;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
492 const ct_data *stree = desc->stat_desc->static_tree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
493 const intf *extra = desc->stat_desc->extra_bits;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
494 int base = desc->stat_desc->extra_base;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
495 int max_length = desc->stat_desc->max_length;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
496 int h; /* heap index */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
497 int n, m; /* iterate over the tree elements */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
498 int bits; /* bit length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
499 int xbits; /* extra bits */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
500 ush f; /* frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
501 int overflow = 0; /* number of elements with bit length too large */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
502
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
503 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
504
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
505 /* In a first pass, compute the optimal bit lengths (which may
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
506 * overflow in the case of the bit length tree).
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
507 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
508 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
509
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
510 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
511 n = s->heap[h];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
512 bits = tree[tree[n].Dad].Len + 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
513 if (bits > max_length) bits = max_length, overflow++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
514 tree[n].Len = (ush)bits;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
515 /* We overwrite tree[n].Dad which is no longer needed */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
516
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
517 if (n > max_code) continue; /* not a leaf node */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
518
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
519 s->bl_count[bits]++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
520 xbits = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
521 if (n >= base) xbits = extra[n-base];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
522 f = tree[n].Freq;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
523 s->opt_len += (ulg)f * (unsigned)(bits + xbits);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
524 if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
525 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
526 if (overflow == 0) return;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
527
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
528 Tracev((stderr,"\nbit length overflow\n"));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
529 /* This happens for example on obj2 and pic of the Calgary corpus */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
530
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
531 /* Find the first bit length which could increase: */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
532 do {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
533 bits = max_length-1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
534 while (s->bl_count[bits] == 0) bits--;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
535 s->bl_count[bits]--; /* move one leaf down the tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
536 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
537 s->bl_count[max_length]--;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
538 /* The brother of the overflow item also moves one step up,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
539 * but this does not affect bl_count[max_length]
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
540 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
541 overflow -= 2;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
542 } while (overflow > 0);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
543
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
544 /* Now recompute all bit lengths, scanning in increasing frequency.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
545 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
546 * lengths instead of fixing only the wrong ones. This idea is taken
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
547 * from 'ar' written by Haruhiko Okumura.)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
548 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
549 for (bits = max_length; bits != 0; bits--) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
550 n = s->bl_count[bits];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
551 while (n != 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
552 m = s->heap[--h];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
553 if (m > max_code) continue;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
554 if ((unsigned) tree[m].Len != (unsigned) bits) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
555 Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
556 s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
557 tree[m].Len = (ush)bits;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
558 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
559 n--;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
560 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
561 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
562 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
563
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
564 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
565 * Generate the codes for a given tree and bit counts (which need not be
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
566 * optimal).
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
567 * IN assertion: the array bl_count contains the bit length statistics for
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
568 * the given tree and the field len is set for all tree elements.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
569 * OUT assertion: the field code is set for all tree elements of non
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
570 * zero code length.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
571 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
572 local void gen_codes (tree, max_code, bl_count)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
573 ct_data *tree; /* the tree to decorate */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
574 int max_code; /* largest code with non zero frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
575 ushf *bl_count; /* number of codes at each bit length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
576 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
577 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
578 unsigned code = 0; /* running code value */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
579 int bits; /* bit index */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
580 int n; /* code index */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
581
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
582 /* The distribution counts are first used to generate the code values
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
583 * without bit reversal.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
584 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
585 for (bits = 1; bits <= MAX_BITS; bits++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
586 code = (code + bl_count[bits-1]) << 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
587 next_code[bits] = (ush)code;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
588 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
589 /* Check that the bit counts in bl_count are consistent. The last code
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
590 * must be all ones.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
591 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
592 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
593 "inconsistent bit counts");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
594 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
595
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
596 for (n = 0; n <= max_code; n++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
597 int len = tree[n].Len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
598 if (len == 0) continue;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
599 /* Now reverse the bits */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
600 tree[n].Code = (ush)bi_reverse(next_code[len]++, len);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
601
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
602 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
603 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
604 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
605 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
606
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
607 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
608 * Construct one Huffman tree and assigns the code bit strings and lengths.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
609 * Update the total bit length for the current block.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
610 * IN assertion: the field freq is set for all tree elements.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
611 * OUT assertions: the fields len and code are set to the optimal bit length
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
612 * and corresponding code. The length opt_len is updated; static_len is
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
613 * also updated if stree is not null. The field max_code is set.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
614 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
615 local void build_tree(s, desc)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
616 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
617 tree_desc *desc; /* the tree descriptor */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
618 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
619 ct_data *tree = desc->dyn_tree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
620 const ct_data *stree = desc->stat_desc->static_tree;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
621 int elems = desc->stat_desc->elems;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
622 int n, m; /* iterate over heap elements */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
623 int max_code = -1; /* largest code with non zero frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
624 int node; /* new node being created */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
625
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
626 /* Construct the initial heap, with least frequent element in
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
627 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
628 * heap[0] is not used.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
629 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
630 s->heap_len = 0, s->heap_max = HEAP_SIZE;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
631
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
632 for (n = 0; n < elems; n++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
633 if (tree[n].Freq != 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
634 s->heap[++(s->heap_len)] = max_code = n;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
635 s->depth[n] = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
636 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
637 tree[n].Len = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
638 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
639 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
640
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
641 /* The pkzip format requires that at least one distance code exists,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
642 * and that at least one bit should be sent even if there is only one
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
643 * possible code. So to avoid special checks later on we force at least
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
644 * two codes of non zero frequency.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
645 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
646 while (s->heap_len < 2) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
647 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
648 tree[node].Freq = 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
649 s->depth[node] = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
650 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
651 /* node is 0 or 1 so it does not have extra bits */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
652 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
653 desc->max_code = max_code;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
654
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
655 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
656 * establish sub-heaps of increasing lengths:
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
657 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
658 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
659
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
660 /* Construct the Huffman tree by repeatedly combining the least two
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
661 * frequent nodes.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
662 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
663 node = elems; /* next internal node of the tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
664 do {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
665 pqremove(s, tree, n); /* n = node of least frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
666 m = s->heap[SMALLEST]; /* m = node of next least frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
667
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
668 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
669 s->heap[--(s->heap_max)] = m;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
670
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
671 /* Create a new node father of n and m */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
672 tree[node].Freq = tree[n].Freq + tree[m].Freq;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
673 s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
674 s->depth[n] : s->depth[m]) + 1);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
675 tree[n].Dad = tree[m].Dad = (ush)node;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
676 #ifdef DUMP_BL_TREE
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
677 if (tree == s->bl_tree) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
678 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
679 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
680 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
681 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
682 /* and insert the new node in the heap */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
683 s->heap[SMALLEST] = node++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
684 pqdownheap(s, tree, SMALLEST);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
685
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
686 } while (s->heap_len >= 2);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
687
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
688 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
689
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
690 /* At this point, the fields freq and dad are set. We can now
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
691 * generate the bit lengths.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
692 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
693 gen_bitlen(s, (tree_desc *)desc);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
694
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
695 /* The field len is now set, we can generate the bit codes */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
696 gen_codes ((ct_data *)tree, max_code, s->bl_count);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
697 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
698
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
699 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
700 * Scan a literal or distance tree to determine the frequencies of the codes
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
701 * in the bit length tree.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
702 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
703 local void scan_tree (s, tree, max_code)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
704 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
705 ct_data *tree; /* the tree to be scanned */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
706 int max_code; /* and its largest code of non zero frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
707 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
708 int n; /* iterates over all tree elements */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
709 int prevlen = -1; /* last emitted length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
710 int curlen; /* length of current code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
711 int nextlen = tree[0].Len; /* length of next code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
712 int count = 0; /* repeat count of the current code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
713 int max_count = 7; /* max repeat count */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
714 int min_count = 4; /* min repeat count */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
715
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
716 if (nextlen == 0) max_count = 138, min_count = 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
717 tree[max_code+1].Len = (ush)0xffff; /* guard */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
718
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
719 for (n = 0; n <= max_code; n++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
720 curlen = nextlen; nextlen = tree[n+1].Len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
721 if (++count < max_count && curlen == nextlen) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
722 continue;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
723 } else if (count < min_count) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
724 s->bl_tree[curlen].Freq += count;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
725 } else if (curlen != 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
726 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
727 s->bl_tree[REP_3_6].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
728 } else if (count <= 10) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
729 s->bl_tree[REPZ_3_10].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
730 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
731 s->bl_tree[REPZ_11_138].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
732 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
733 count = 0; prevlen = curlen;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
734 if (nextlen == 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
735 max_count = 138, min_count = 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
736 } else if (curlen == nextlen) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
737 max_count = 6, min_count = 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
738 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
739 max_count = 7, min_count = 4;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
740 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
741 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
742 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
743
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
744 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
745 * Send a literal or distance tree in compressed form, using the codes in
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
746 * bl_tree.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
747 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
748 local void send_tree (s, tree, max_code)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
749 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
750 ct_data *tree; /* the tree to be scanned */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
751 int max_code; /* and its largest code of non zero frequency */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
752 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
753 int n; /* iterates over all tree elements */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
754 int prevlen = -1; /* last emitted length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
755 int curlen; /* length of current code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
756 int nextlen = tree[0].Len; /* length of next code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
757 int count = 0; /* repeat count of the current code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
758 int max_count = 7; /* max repeat count */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
759 int min_count = 4; /* min repeat count */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
760
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
761 /* tree[max_code+1].Len = -1; */ /* guard already set */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
762 if (nextlen == 0) max_count = 138, min_count = 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
763
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
764 for (n = 0; n <= max_code; n++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
765 curlen = nextlen; nextlen = tree[n+1].Len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
766 if (++count < max_count && curlen == nextlen) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
767 continue;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
768 } else if (count < min_count) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
769 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
770
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
771 } else if (curlen != 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
772 if (curlen != prevlen) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
773 send_code(s, curlen, s->bl_tree); count--;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
774 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
775 Assert(count >= 3 && count <= 6, " 3_6?");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
776 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
777
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
778 } else if (count <= 10) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
779 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
780
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
781 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
782 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
783 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
784 count = 0; prevlen = curlen;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
785 if (nextlen == 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
786 max_count = 138, min_count = 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
787 } else if (curlen == nextlen) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
788 max_count = 6, min_count = 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
789 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
790 max_count = 7, min_count = 4;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
791 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
792 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
793 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
794
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
795 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
796 * Construct the Huffman tree for the bit lengths and return the index in
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
797 * bl_order of the last bit length code to send.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
798 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
799 local int build_bl_tree(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
800 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
801 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
802 int max_blindex; /* index of last bit length code of non zero freq */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
803
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
804 /* Determine the bit length frequencies for literal and distance trees */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
805 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
806 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
807
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
808 /* Build the bit length tree: */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
809 build_tree(s, (tree_desc *)(&(s->bl_desc)));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
810 /* opt_len now includes the length of the tree representations, except
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
811 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
812 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
813
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
814 /* Determine the number of bit length codes to send. The pkzip format
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
815 * requires that at least 4 bit length codes be sent. (appnote.txt says
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
816 * 3 but the actual value used is 4.)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
817 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
818 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
819 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
820 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
821 /* Update opt_len to include the bit length tree and counts */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
822 s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
823 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
824 s->opt_len, s->static_len));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
825
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
826 return max_blindex;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
827 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
828
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
829 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
830 * Send the header for a block using dynamic Huffman trees: the counts, the
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
831 * lengths of the bit length codes, the literal tree and the distance tree.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
832 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
833 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
834 local void send_all_trees(s, lcodes, dcodes, blcodes)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
835 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
836 int lcodes, dcodes, blcodes; /* number of codes for each tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
837 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
838 int rank; /* index in bl_order */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
839
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
840 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
841 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
842 "too many codes");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
843 Tracev((stderr, "\nbl counts: "));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
844 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
845 send_bits(s, dcodes-1, 5);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
846 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
847 for (rank = 0; rank < blcodes; rank++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
848 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
849 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
850 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
851 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
852
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
853 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
854 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
855
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
856 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
857 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
858 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
859
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
860 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
861 * Send a stored block
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
862 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
863 void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
864 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
865 charf *buf; /* input block */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
866 ulg stored_len; /* length of input block */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
867 int last; /* one if this is the last block for a file */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
868 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
869 send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
870 bi_windup(s); /* align on byte boundary */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
871 put_short(s, (ush)stored_len);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
872 put_short(s, (ush)~stored_len);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
873 zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
874 s->pending += stored_len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
875 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
876 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
877 s->compressed_len += (stored_len + 4) << 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
878 s->bits_sent += 2*16;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
879 s->bits_sent += stored_len<<3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
880 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
881 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
882
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
883 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
884 * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
885 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
886 void ZLIB_INTERNAL _tr_flush_bits(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
887 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
888 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
889 bi_flush(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
890 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
891
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
892 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
893 * Send one empty static block to give enough lookahead for inflate.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
894 * This takes 10 bits, of which 7 may remain in the bit buffer.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
895 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
896 void ZLIB_INTERNAL _tr_align(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
897 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
898 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
899 send_bits(s, STATIC_TREES<<1, 3);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
900 send_code(s, END_BLOCK, static_ltree);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
901 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
902 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
903 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
904 bi_flush(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
905 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
906
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
907 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
908 * Determine the best encoding for the current block: dynamic trees, static
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
909 * trees or store, and write out the encoded block.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
910 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
911 void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
912 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
913 charf *buf; /* input block, or NULL if too old */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
914 ulg stored_len; /* length of input block */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
915 int last; /* one if this is the last block for a file */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
916 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
917 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
918 int max_blindex = 0; /* index of last bit length code of non zero freq */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
919
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
920 /* Build the Huffman trees unless a stored block is forced */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
921 if (s->level > 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
922
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
923 /* Check if the file is binary or text */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
924 if (s->strm->data_type == Z_UNKNOWN)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
925 s->strm->data_type = detect_data_type(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
926
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
927 /* Construct the literal and distance trees */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
928 build_tree(s, (tree_desc *)(&(s->l_desc)));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
929 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
930 s->static_len));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
931
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
932 build_tree(s, (tree_desc *)(&(s->d_desc)));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
933 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
934 s->static_len));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
935 /* At this point, opt_len and static_len are the total bit lengths of
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
936 * the compressed block data, excluding the tree representations.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
937 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
938
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
939 /* Build the bit length tree for the above two trees, and get the index
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
940 * in bl_order of the last bit length code to send.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
941 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
942 max_blindex = build_bl_tree(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
943
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
944 /* Determine the best encoding. Compute the block lengths in bytes. */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
945 opt_lenb = (s->opt_len+3+7)>>3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
946 static_lenb = (s->static_len+3+7)>>3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
947
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
948 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
949 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
950 s->last_lit));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
951
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
952 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
953
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
954 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
955 Assert(buf != (char*)0, "lost buf");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
956 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
957 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
958
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
959 #ifdef FORCE_STORED
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
960 if (buf != (char*)0) { /* force stored block */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
961 #else
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
962 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
963 /* 4: two words for the lengths */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
964 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
965 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
966 * Otherwise we can't have processed more than WSIZE input bytes since
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
967 * the last block flush, because compression would have been
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
968 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
969 * transform a block into a stored block.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
970 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
971 _tr_stored_block(s, buf, stored_len, last);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
972
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
973 #ifdef FORCE_STATIC
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
974 } else if (static_lenb >= 0) { /* force static trees */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
975 #else
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
976 } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
977 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
978 send_bits(s, (STATIC_TREES<<1)+last, 3);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
979 compress_block(s, (const ct_data *)static_ltree,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
980 (const ct_data *)static_dtree);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
981 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
982 s->compressed_len += 3 + s->static_len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
983 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
984 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
985 send_bits(s, (DYN_TREES<<1)+last, 3);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
986 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
987 max_blindex+1);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
988 compress_block(s, (const ct_data *)s->dyn_ltree,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
989 (const ct_data *)s->dyn_dtree);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
990 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
991 s->compressed_len += 3 + s->opt_len;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
992 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
993 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
994 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
995 /* The above check is made mod 2^32, for files larger than 512 MB
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
996 * and uLong implemented on 32 bits.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
997 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
998 init_block(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
999
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1000 if (last) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1001 bi_windup(s);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1002 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1003 s->compressed_len += 7; /* align on byte boundary */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1004 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1005 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1006 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1007 s->compressed_len-7*last));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1008 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1009
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1010 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1011 * Save the match info and tally the frequency counts. Return true if
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1012 * the current block must be flushed.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1013 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1014 int ZLIB_INTERNAL _tr_tally (s, dist, lc)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1015 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1016 unsigned dist; /* distance of matched string */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1017 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1018 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1019 s->d_buf[s->last_lit] = (ush)dist;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1020 s->l_buf[s->last_lit++] = (uch)lc;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1021 if (dist == 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1022 /* lc is the unmatched char */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1023 s->dyn_ltree[lc].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1024 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1025 s->matches++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1026 /* Here, lc is the match length - MIN_MATCH */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1027 dist--; /* dist = match distance - 1 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1028 Assert((ush)dist < (ush)MAX_DIST(s) &&
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1029 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1030 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1031
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1032 s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1033 s->dyn_dtree[d_code(dist)].Freq++;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1034 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1035
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1036 #ifdef TRUNCATE_BLOCK
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1037 /* Try to guess if it is profitable to stop the current block here */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1038 if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1039 /* Compute an upper bound for the compressed length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1040 ulg out_length = (ulg)s->last_lit*8L;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1041 ulg in_length = (ulg)((long)s->strstart - s->block_start);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1042 int dcode;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1043 for (dcode = 0; dcode < D_CODES; dcode++) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1044 out_length += (ulg)s->dyn_dtree[dcode].Freq *
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1045 (5L+extra_dbits[dcode]);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1046 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1047 out_length >>= 3;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1048 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1049 s->last_lit, in_length, out_length,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1050 100L - out_length*100L/in_length));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1051 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1052 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1053 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1054 return (s->last_lit == s->lit_bufsize-1);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1055 /* We avoid equality with lit_bufsize because of wraparound at 64K
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1056 * on 16 bit machines and because stored blocks are restricted to
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1057 * 64K-1 bytes.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1058 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1059 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1060
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1061 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1062 * Send the block data compressed using the given Huffman trees
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1063 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1064 local void compress_block(s, ltree, dtree)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1065 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1066 const ct_data *ltree; /* literal tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1067 const ct_data *dtree; /* distance tree */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1068 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1069 unsigned dist; /* distance of matched string */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1070 int lc; /* match length or unmatched char (if dist == 0) */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1071 unsigned lx = 0; /* running index in l_buf */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1072 unsigned code; /* the code to send */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1073 int extra; /* number of extra bits to send */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1074
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1075 if (s->last_lit != 0) do {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1076 dist = s->d_buf[lx];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1077 lc = s->l_buf[lx++];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1078 if (dist == 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1079 send_code(s, lc, ltree); /* send a literal byte */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1080 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1081 } else {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1082 /* Here, lc is the match length - MIN_MATCH */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1083 code = _length_code[lc];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1084 send_code(s, code+LITERALS+1, ltree); /* send the length code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1085 extra = extra_lbits[code];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1086 if (extra != 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1087 lc -= base_length[code];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1088 send_bits(s, lc, extra); /* send the extra length bits */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1089 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1090 dist--; /* dist is now the match distance - 1 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1091 code = d_code(dist);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1092 Assert (code < D_CODES, "bad d_code");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1093
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1094 send_code(s, code, dtree); /* send the distance code */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1095 extra = extra_dbits[code];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1096 if (extra != 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1097 dist -= (unsigned)base_dist[code];
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1098 send_bits(s, dist, extra); /* send the extra distance bits */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1099 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1100 } /* literal or match pair ? */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1101
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1102 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1103 Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1104 "pendingBuf overflow");
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1105
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1106 } while (lx < s->last_lit);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1107
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1108 send_code(s, END_BLOCK, ltree);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1109 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1110
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1111 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1112 * Check if the data type is TEXT or BINARY, using the following algorithm:
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1113 * - TEXT if the two conditions below are satisfied:
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1114 * a) There are no non-portable control characters belonging to the
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1115 * "black list" (0..6, 14..25, 28..31).
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1116 * b) There is at least one printable character belonging to the
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1117 * "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1118 * - BINARY otherwise.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1119 * - The following partially-portable control characters form a
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1120 * "gray list" that is ignored in this detection algorithm:
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1121 * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1122 * IN assertion: the fields Freq of dyn_ltree are set.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1123 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1124 local int detect_data_type(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1125 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1126 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1127 /* black_mask is the bit mask of black-listed bytes
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1128 * set bits 0..6, 14..25, and 28..31
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1129 * 0xf3ffc07f = binary 11110011111111111100000001111111
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1130 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1131 unsigned long black_mask = 0xf3ffc07fUL;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1132 int n;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1133
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1134 /* Check for non-textual ("black-listed") bytes. */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1135 for (n = 0; n <= 31; n++, black_mask >>= 1)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1136 if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1137 return Z_BINARY;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1138
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1139 /* Check for textual ("white-listed") bytes. */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1140 if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1141 || s->dyn_ltree[13].Freq != 0)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1142 return Z_TEXT;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1143 for (n = 32; n < LITERALS; n++)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1144 if (s->dyn_ltree[n].Freq != 0)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1145 return Z_TEXT;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1146
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1147 /* There are no "black-listed" or "white-listed" bytes:
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1148 * this stream either is empty or has tolerated ("gray-listed") bytes only.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1149 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1150 return Z_BINARY;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1151 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1152
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1153 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1154 * Reverse the first len bits of a code, using straightforward code (a faster
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1155 * method would use a table)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1156 * IN assertion: 1 <= len <= 15
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1157 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1158 local unsigned bi_reverse(code, len)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1159 unsigned code; /* the value to invert */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1160 int len; /* its bit length */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1161 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1162 register unsigned res = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1163 do {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1164 res |= code & 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1165 code >>= 1, res <<= 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1166 } while (--len > 0);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1167 return res >> 1;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1168 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1169
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1170 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1171 * Flush the bit buffer, keeping at most 7 bits in it.
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1172 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1173 local void bi_flush(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1174 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1175 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1176 if (s->bi_valid == 16) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1177 put_short(s, s->bi_buf);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1178 s->bi_buf = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1179 s->bi_valid = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1180 } else if (s->bi_valid >= 8) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1181 put_byte(s, (Byte)s->bi_buf);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1182 s->bi_buf >>= 8;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1183 s->bi_valid -= 8;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1184 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1185 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1186
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1187 /* ===========================================================================
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1188 * Flush the bit buffer and align the output on a byte boundary
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1189 */
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1190 local void bi_windup(s)
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1191 deflate_state *s;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1192 {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1193 if (s->bi_valid > 8) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1194 put_short(s, s->bi_buf);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1195 } else if (s->bi_valid > 0) {
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1196 put_byte(s, (Byte)s->bi_buf);
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1197 }
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1198 s->bi_buf = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1199 s->bi_valid = 0;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1200 #ifdef ZLIB_DEBUG
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1201 s->bits_sent = (s->bits_sent+7) & ~7;
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1202 #endif
00d788dac91a Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
1203 }