rev |
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1 /* deflate.c -- compress data using the deflation algorithm
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2 * Copyright (C) 1995-2005 Jean-loup Gailly.
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3 * For conditions of distribution and use, see copyright notice in zlib.h
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4 */
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5
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6 /*
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7 * ALGORITHM
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8 *
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9 * The "deflation" process depends on being able to identify portions
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10 * of the input text which are identical to earlier input (within a
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11 * sliding window trailing behind the input currently being processed).
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12 *
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13 * The most straightforward technique turns out to be the fastest for
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14 * most input files: try all possible matches and select the longest.
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15 * The key feature of this algorithm is that insertions into the string
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16 * dictionary are very simple and thus fast, and deletions are avoided
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17 * completely. Insertions are performed at each input character, whereas
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18 * string matches are performed only when the previous match ends. So it
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19 * is preferable to spend more time in matches to allow very fast string
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20 * insertions and avoid deletions. The matching algorithm for small
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21 * strings is inspired from that of Rabin & Karp. A brute force approach
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22 * is used to find longer strings when a small match has been found.
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23 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
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24 * (by Leonid Broukhis).
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25 * A previous version of this file used a more sophisticated algorithm
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26 * (by Fiala and Greene) which is guaranteed to run in linear amortized
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27 * time, but has a larger average cost, uses more memory and is patented.
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28 * However the F&G algorithm may be faster for some highly redundant
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29 * files if the parameter max_chain_length (described below) is too large.
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30 *
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31 * ACKNOWLEDGEMENTS
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32 *
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33 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
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34 * I found it in 'freeze' written by Leonid Broukhis.
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35 * Thanks to many people for bug reports and testing.
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36 *
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37 * REFERENCES
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38 *
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39 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
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40 * Available in http://www.ietf.org/rfc/rfc1951.txt
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41 *
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42 * A description of the Rabin and Karp algorithm is given in the book
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43 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
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44 *
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45 * Fiala,E.R., and Greene,D.H.
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46 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
|
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47 *
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48 */
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49
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50 /* @(#) $Id$ */
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51
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52 #include "deflate.h"
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53
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54 const char deflate_copyright[] =
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55 " deflate 1.2.3 Copyright 1995-2005 Jean-loup Gailly ";
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56 /*
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57 If you use the zlib library in a product, an acknowledgment is welcome
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58 in the documentation of your product. If for some reason you cannot
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59 include such an acknowledgment, I would appreciate that you keep this
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60 copyright string in the executable of your product.
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61 */
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62
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63 /* ===========================================================================
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64 * Function prototypes.
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65 */
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66 typedef enum {
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67 need_more, /* block not completed, need more input or more output */
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68 block_done, /* block flush performed */
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69 finish_started, /* finish started, need only more output at next deflate */
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70 finish_done /* finish done, accept no more input or output */
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71 } block_state;
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72
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73 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
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74 /* Compression function. Returns the block state after the call. */
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75
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76 local void fill_window OF((deflate_state *s));
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77 local block_state deflate_stored OF((deflate_state *s, int flush));
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78 local block_state deflate_fast OF((deflate_state *s, int flush));
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79 #ifndef FASTEST
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80 local block_state deflate_slow OF((deflate_state *s, int flush));
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81 #endif
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82 local void lm_init OF((deflate_state *s));
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83 local void putShortMSB OF((deflate_state *s, uInt b));
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84 local void flush_pending OF((z_streamp strm));
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85 local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
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86 #ifndef FASTEST
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87 #ifdef ASMV
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88 void match_init OF((void)); /* asm code initialization */
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89 uInt longest_match OF((deflate_state *s, IPos cur_match));
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90 #else
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91 local uInt longest_match OF((deflate_state *s, IPos cur_match));
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92 #endif
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93 #endif
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94 local uInt longest_match_fast OF((deflate_state *s, IPos cur_match));
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95
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96 #ifdef DEBUG
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97 local void check_match OF((deflate_state *s, IPos start, IPos match,
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98 int length));
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99 #endif
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100
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101 /* ===========================================================================
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102 * Local data
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103 */
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104
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105 #define NIL 0
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106 /* Tail of hash chains */
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107
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108 #ifndef TOO_FAR
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109 # define TOO_FAR 4096
|
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110 #endif
|
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111 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
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112
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113 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
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114 /* Minimum amount of lookahead, except at the end of the input file.
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115 * See deflate.c for comments about the MIN_MATCH+1.
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116 */
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117
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118 /* Values for max_lazy_match, good_match and max_chain_length, depending on
|
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119 * the desired pack level (0..9). The values given below have been tuned to
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120 * exclude worst case performance for pathological files. Better values may be
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121 * found for specific files.
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122 */
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123 typedef struct config_s {
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124 ush good_length; /* reduce lazy search above this match length */
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125 ush max_lazy; /* do not perform lazy search above this match length */
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126 ush nice_length; /* quit search above this match length */
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127 ush max_chain;
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128 compress_func func;
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129 } config;
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130
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131 #ifdef FASTEST
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132 local const config configuration_table[2] = {
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133 /* good lazy nice chain */
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134 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
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135 /* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */
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136 #else
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137 local const config configuration_table[10] = {
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138 /* good lazy nice chain */
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139 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
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140 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
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141 /* 2 */ {4, 5, 16, 8, deflate_fast},
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142 /* 3 */ {4, 6, 32, 32, deflate_fast},
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143
|
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144 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
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145 /* 5 */ {8, 16, 32, 32, deflate_slow},
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146 /* 6 */ {8, 16, 128, 128, deflate_slow},
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147 /* 7 */ {8, 32, 128, 256, deflate_slow},
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148 /* 8 */ {32, 128, 258, 1024, deflate_slow},
|
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149 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
|
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150 #endif
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151
|
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152 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
|
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153 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
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154 * meaning.
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155 */
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156
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157 #define EQUAL 0
|
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158 /* result of memcmp for equal strings */
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159
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160 #ifndef NO_DUMMY_DECL
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161 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
|
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162 #endif
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163
|
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164 /* ===========================================================================
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165 * Update a hash value with the given input byte
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166 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
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167 * input characters, so that a running hash key can be computed from the
|
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168 * previous key instead of complete recalculation each time.
|
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169 */
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170 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
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171
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172
|
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173 /* ===========================================================================
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174 * Insert string str in the dictionary and set match_head to the previous head
|
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175 * of the hash chain (the most recent string with same hash key). Return
|
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176 * the previous length of the hash chain.
|
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177 * If this file is compiled with -DFASTEST, the compression level is forced
|
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178 * to 1, and no hash chains are maintained.
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179 * IN assertion: all calls to to INSERT_STRING are made with consecutive
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180 * input characters and the first MIN_MATCH bytes of str are valid
|
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181 * (except for the last MIN_MATCH-1 bytes of the input file).
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182 */
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183 #ifdef FASTEST
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184 #define INSERT_STRING(s, str, match_head) \
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185 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
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186 match_head = s->head[s->ins_h], \
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187 s->head[s->ins_h] = (Pos)(str))
|
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188 #else
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189 #define INSERT_STRING(s, str, match_head) \
|
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190 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
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191 match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
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192 s->head[s->ins_h] = (Pos)(str))
|
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193 #endif
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194
|
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195 /* ===========================================================================
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196 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
|
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197 * prev[] will be initialized on the fly.
|
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198 */
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199 #define CLEAR_HASH(s) \
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200 s->head[s->hash_size-1] = NIL; \
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201 zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
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202
|
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203 /* ========================================================================= */
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204 int ZEXPORT deflateInit_(strm, level, version, stream_size)
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205 z_streamp strm;
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206 int level;
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207 const char *version;
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208 int stream_size;
|
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209 {
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210 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
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211 Z_DEFAULT_STRATEGY, version, stream_size);
|
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212 /* To do: ignore strm->next_in if we use it as window */
|
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213 }
|
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214
|
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215 /* ========================================================================= */
|
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216 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
|
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217 version, stream_size)
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218 z_streamp strm;
|
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219 int level;
|
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220 int method;
|
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221 int windowBits;
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222 int memLevel;
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223 int strategy;
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224 const char *version;
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225 int stream_size;
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226 {
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227 deflate_state *s;
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228 int wrap = 1;
|
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229 static const char my_version[] = ZLIB_VERSION;
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230
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231 ushf *overlay;
|
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232 /* We overlay pending_buf and d_buf+l_buf. This works since the average
|
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233 * output size for (length,distance) codes is <= 24 bits.
|
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234 */
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235
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236 if (version == Z_NULL || version[0] != my_version[0] ||
|
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237 stream_size != sizeof(z_stream)) {
|
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238 return Z_VERSION_ERROR;
|
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239 }
|
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240 if (strm == Z_NULL) return Z_STREAM_ERROR;
|
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241
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242 strm->msg = Z_NULL;
|
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243 if (strm->zalloc == (alloc_func)0) {
|
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244 strm->zalloc = zcalloc;
|
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245 strm->opaque = (voidpf)0;
|
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246 }
|
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247 if (strm->zfree == (free_func)0) strm->zfree = zcfree;
|
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248
|
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249 #ifdef FASTEST
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250 if (level != 0) level = 1;
|
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251 #else
|
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252 if (level == Z_DEFAULT_COMPRESSION) level = 6;
|
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253 #endif
|
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254
|
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255 if (windowBits < 0) { /* suppress zlib wrapper */
|
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256 wrap = 0;
|
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257 windowBits = -windowBits;
|
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258 }
|
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259 #ifdef GZIP
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260 else if (windowBits > 15) {
|
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261 wrap = 2; /* write gzip wrapper instead */
|
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262 windowBits -= 16;
|
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263 }
|
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264 #endif
|
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265 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
|
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266 windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
|
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267 strategy < 0 || strategy > Z_FIXED) {
|
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268 return Z_STREAM_ERROR;
|
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|
269 }
|
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270 if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */
|
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271 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
|
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272 if (s == Z_NULL) return Z_MEM_ERROR;
|
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273 strm->state = (struct internal_state FAR *)s;
|
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274 s->strm = strm;
|
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275
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276 s->wrap = wrap;
|
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277 s->gzhead = Z_NULL;
|
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278 s->w_bits = windowBits;
|
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279 s->w_size = 1 << s->w_bits;
|
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280 s->w_mask = s->w_size - 1;
|
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281
|
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282 s->hash_bits = memLevel + 7;
|
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283 s->hash_size = 1 << s->hash_bits;
|
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284 s->hash_mask = s->hash_size - 1;
|
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285 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
|
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286
|
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287 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
|
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288 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
|
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289 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
|
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290
|
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291 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
|
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292
|
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293 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
|
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294 s->pending_buf = (uchf *) overlay;
|
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295 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
|
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|
296
|
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|
297 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
|
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298 s->pending_buf == Z_NULL) {
|
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|
299 s->status = FINISH_STATE;
|
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|
300 strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
|
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301 deflateEnd (strm);
|
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|
302 return Z_MEM_ERROR;
|
nuclear@0
|
303 }
|
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|
304 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
|
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305 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
|
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|
306
|
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307 s->level = level;
|
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|
308 s->strategy = strategy;
|
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|
309 s->method = (Byte)method;
|
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|
310
|
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311 return deflateReset(strm);
|
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|
312 }
|
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|
313
|
nuclear@0
|
314 /* ========================================================================= */
|
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|
315 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
|
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|
316 z_streamp strm;
|
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|
317 const Bytef *dictionary;
|
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|
318 uInt dictLength;
|
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|
319 {
|
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|
320 deflate_state *s;
|
nuclear@0
|
321 uInt length = dictLength;
|
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|
322 uInt n;
|
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|
323 IPos hash_head = 0;
|
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|
324
|
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|
325 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL ||
|
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326 strm->state->wrap == 2 ||
|
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|
327 (strm->state->wrap == 1 && strm->state->status != INIT_STATE))
|
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|
328 return Z_STREAM_ERROR;
|
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|
329
|
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|
330 s = strm->state;
|
nuclear@0
|
331 if (s->wrap)
|
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|
332 strm->adler = adler32(strm->adler, dictionary, dictLength);
|
nuclear@0
|
333
|
nuclear@0
|
334 if (length < MIN_MATCH) return Z_OK;
|
nuclear@0
|
335 if (length > MAX_DIST(s)) {
|
nuclear@0
|
336 length = MAX_DIST(s);
|
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|
337 dictionary += dictLength - length; /* use the tail of the dictionary */
|
nuclear@0
|
338 }
|
nuclear@0
|
339 zmemcpy(s->window, dictionary, length);
|
nuclear@0
|
340 s->strstart = length;
|
nuclear@0
|
341 s->block_start = (long)length;
|
nuclear@0
|
342
|
nuclear@0
|
343 /* Insert all strings in the hash table (except for the last two bytes).
|
nuclear@0
|
344 * s->lookahead stays null, so s->ins_h will be recomputed at the next
|
nuclear@0
|
345 * call of fill_window.
|
nuclear@0
|
346 */
|
nuclear@0
|
347 s->ins_h = s->window[0];
|
nuclear@0
|
348 UPDATE_HASH(s, s->ins_h, s->window[1]);
|
nuclear@0
|
349 for (n = 0; n <= length - MIN_MATCH; n++) {
|
nuclear@0
|
350 INSERT_STRING(s, n, hash_head);
|
nuclear@0
|
351 }
|
nuclear@0
|
352 if (hash_head) hash_head = 0; /* to make compiler happy */
|
nuclear@0
|
353 return Z_OK;
|
nuclear@0
|
354 }
|
nuclear@0
|
355
|
nuclear@0
|
356 /* ========================================================================= */
|
nuclear@0
|
357 int ZEXPORT deflateReset (strm)
|
nuclear@0
|
358 z_streamp strm;
|
nuclear@0
|
359 {
|
nuclear@0
|
360 deflate_state *s;
|
nuclear@0
|
361
|
nuclear@0
|
362 if (strm == Z_NULL || strm->state == Z_NULL ||
|
nuclear@0
|
363 strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) {
|
nuclear@0
|
364 return Z_STREAM_ERROR;
|
nuclear@0
|
365 }
|
nuclear@0
|
366
|
nuclear@0
|
367 strm->total_in = strm->total_out = 0;
|
nuclear@0
|
368 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
|
nuclear@0
|
369 strm->data_type = Z_UNKNOWN;
|
nuclear@0
|
370
|
nuclear@0
|
371 s = (deflate_state *)strm->state;
|
nuclear@0
|
372 s->pending = 0;
|
nuclear@0
|
373 s->pending_out = s->pending_buf;
|
nuclear@0
|
374
|
nuclear@0
|
375 if (s->wrap < 0) {
|
nuclear@0
|
376 s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
|
nuclear@0
|
377 }
|
nuclear@0
|
378 s->status = s->wrap ? INIT_STATE : BUSY_STATE;
|
nuclear@0
|
379 strm->adler =
|
nuclear@0
|
380 #ifdef GZIP
|
nuclear@0
|
381 s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
|
nuclear@0
|
382 #endif
|
nuclear@0
|
383 adler32(0L, Z_NULL, 0);
|
nuclear@0
|
384 s->last_flush = Z_NO_FLUSH;
|
nuclear@0
|
385
|
nuclear@0
|
386 _tr_init(s);
|
nuclear@0
|
387 lm_init(s);
|
nuclear@0
|
388
|
nuclear@0
|
389 return Z_OK;
|
nuclear@0
|
390 }
|
nuclear@0
|
391
|
nuclear@0
|
392 /* ========================================================================= */
|
nuclear@0
|
393 int ZEXPORT deflateSetHeader (strm, head)
|
nuclear@0
|
394 z_streamp strm;
|
nuclear@0
|
395 gz_headerp head;
|
nuclear@0
|
396 {
|
nuclear@0
|
397 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
|
nuclear@0
|
398 if (strm->state->wrap != 2) return Z_STREAM_ERROR;
|
nuclear@0
|
399 strm->state->gzhead = head;
|
nuclear@0
|
400 return Z_OK;
|
nuclear@0
|
401 }
|
nuclear@0
|
402
|
nuclear@0
|
403 /* ========================================================================= */
|
nuclear@0
|
404 int ZEXPORT deflatePrime (strm, bits, value)
|
nuclear@0
|
405 z_streamp strm;
|
nuclear@0
|
406 int bits;
|
nuclear@0
|
407 int value;
|
nuclear@0
|
408 {
|
nuclear@0
|
409 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
|
nuclear@0
|
410 strm->state->bi_valid = bits;
|
nuclear@0
|
411 strm->state->bi_buf = (ush)(value & ((1 << bits) - 1));
|
nuclear@0
|
412 return Z_OK;
|
nuclear@0
|
413 }
|
nuclear@0
|
414
|
nuclear@0
|
415 /* ========================================================================= */
|
nuclear@0
|
416 int ZEXPORT deflateParams(strm, level, strategy)
|
nuclear@0
|
417 z_streamp strm;
|
nuclear@0
|
418 int level;
|
nuclear@0
|
419 int strategy;
|
nuclear@0
|
420 {
|
nuclear@0
|
421 deflate_state *s;
|
nuclear@0
|
422 compress_func func;
|
nuclear@0
|
423 int err = Z_OK;
|
nuclear@0
|
424
|
nuclear@0
|
425 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
|
nuclear@0
|
426 s = strm->state;
|
nuclear@0
|
427
|
nuclear@0
|
428 #ifdef FASTEST
|
nuclear@0
|
429 if (level != 0) level = 1;
|
nuclear@0
|
430 #else
|
nuclear@0
|
431 if (level == Z_DEFAULT_COMPRESSION) level = 6;
|
nuclear@0
|
432 #endif
|
nuclear@0
|
433 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
|
nuclear@0
|
434 return Z_STREAM_ERROR;
|
nuclear@0
|
435 }
|
nuclear@0
|
436 func = configuration_table[s->level].func;
|
nuclear@0
|
437
|
nuclear@0
|
438 if (func != configuration_table[level].func && strm->total_in != 0) {
|
nuclear@0
|
439 /* Flush the last buffer: */
|
nuclear@0
|
440 err = deflate(strm, Z_PARTIAL_FLUSH);
|
nuclear@0
|
441 }
|
nuclear@0
|
442 if (s->level != level) {
|
nuclear@0
|
443 s->level = level;
|
nuclear@0
|
444 s->max_lazy_match = configuration_table[level].max_lazy;
|
nuclear@0
|
445 s->good_match = configuration_table[level].good_length;
|
nuclear@0
|
446 s->nice_match = configuration_table[level].nice_length;
|
nuclear@0
|
447 s->max_chain_length = configuration_table[level].max_chain;
|
nuclear@0
|
448 }
|
nuclear@0
|
449 s->strategy = strategy;
|
nuclear@0
|
450 return err;
|
nuclear@0
|
451 }
|
nuclear@0
|
452
|
nuclear@0
|
453 /* ========================================================================= */
|
nuclear@0
|
454 int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
|
nuclear@0
|
455 z_streamp strm;
|
nuclear@0
|
456 int good_length;
|
nuclear@0
|
457 int max_lazy;
|
nuclear@0
|
458 int nice_length;
|
nuclear@0
|
459 int max_chain;
|
nuclear@0
|
460 {
|
nuclear@0
|
461 deflate_state *s;
|
nuclear@0
|
462
|
nuclear@0
|
463 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
|
nuclear@0
|
464 s = strm->state;
|
nuclear@0
|
465 s->good_match = good_length;
|
nuclear@0
|
466 s->max_lazy_match = max_lazy;
|
nuclear@0
|
467 s->nice_match = nice_length;
|
nuclear@0
|
468 s->max_chain_length = max_chain;
|
nuclear@0
|
469 return Z_OK;
|
nuclear@0
|
470 }
|
nuclear@0
|
471
|
nuclear@0
|
472 /* =========================================================================
|
nuclear@0
|
473 * For the default windowBits of 15 and memLevel of 8, this function returns
|
nuclear@0
|
474 * a close to exact, as well as small, upper bound on the compressed size.
|
nuclear@0
|
475 * They are coded as constants here for a reason--if the #define's are
|
nuclear@0
|
476 * changed, then this function needs to be changed as well. The return
|
nuclear@0
|
477 * value for 15 and 8 only works for those exact settings.
|
nuclear@0
|
478 *
|
nuclear@0
|
479 * For any setting other than those defaults for windowBits and memLevel,
|
nuclear@0
|
480 * the value returned is a conservative worst case for the maximum expansion
|
nuclear@0
|
481 * resulting from using fixed blocks instead of stored blocks, which deflate
|
nuclear@0
|
482 * can emit on compressed data for some combinations of the parameters.
|
nuclear@0
|
483 *
|
nuclear@0
|
484 * This function could be more sophisticated to provide closer upper bounds
|
nuclear@0
|
485 * for every combination of windowBits and memLevel, as well as wrap.
|
nuclear@0
|
486 * But even the conservative upper bound of about 14% expansion does not
|
nuclear@0
|
487 * seem onerous for output buffer allocation.
|
nuclear@0
|
488 */
|
nuclear@0
|
489 uLong ZEXPORT deflateBound(strm, sourceLen)
|
nuclear@0
|
490 z_streamp strm;
|
nuclear@0
|
491 uLong sourceLen;
|
nuclear@0
|
492 {
|
nuclear@0
|
493 deflate_state *s;
|
nuclear@0
|
494 uLong destLen;
|
nuclear@0
|
495
|
nuclear@0
|
496 /* conservative upper bound */
|
nuclear@0
|
497 destLen = sourceLen +
|
nuclear@0
|
498 ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11;
|
nuclear@0
|
499
|
nuclear@0
|
500 /* if can't get parameters, return conservative bound */
|
nuclear@0
|
501 if (strm == Z_NULL || strm->state == Z_NULL)
|
nuclear@0
|
502 return destLen;
|
nuclear@0
|
503
|
nuclear@0
|
504 /* if not default parameters, return conservative bound */
|
nuclear@0
|
505 s = strm->state;
|
nuclear@0
|
506 if (s->w_bits != 15 || s->hash_bits != 8 + 7)
|
nuclear@0
|
507 return destLen;
|
nuclear@0
|
508
|
nuclear@0
|
509 /* default settings: return tight bound for that case */
|
nuclear@0
|
510 return compressBound(sourceLen);
|
nuclear@0
|
511 }
|
nuclear@0
|
512
|
nuclear@0
|
513 /* =========================================================================
|
nuclear@0
|
514 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
|
nuclear@0
|
515 * IN assertion: the stream state is correct and there is enough room in
|
nuclear@0
|
516 * pending_buf.
|
nuclear@0
|
517 */
|
nuclear@0
|
518 local void putShortMSB (s, b)
|
nuclear@0
|
519 deflate_state *s;
|
nuclear@0
|
520 uInt b;
|
nuclear@0
|
521 {
|
nuclear@0
|
522 put_byte(s, (Byte)(b >> 8));
|
nuclear@0
|
523 put_byte(s, (Byte)(b & 0xff));
|
nuclear@0
|
524 }
|
nuclear@0
|
525
|
nuclear@0
|
526 /* =========================================================================
|
nuclear@0
|
527 * Flush as much pending output as possible. All deflate() output goes
|
nuclear@0
|
528 * through this function so some applications may wish to modify it
|
nuclear@0
|
529 * to avoid allocating a large strm->next_out buffer and copying into it.
|
nuclear@0
|
530 * (See also read_buf()).
|
nuclear@0
|
531 */
|
nuclear@0
|
532 local void flush_pending(strm)
|
nuclear@0
|
533 z_streamp strm;
|
nuclear@0
|
534 {
|
nuclear@0
|
535 unsigned len = strm->state->pending;
|
nuclear@0
|
536
|
nuclear@0
|
537 if (len > strm->avail_out) len = strm->avail_out;
|
nuclear@0
|
538 if (len == 0) return;
|
nuclear@0
|
539
|
nuclear@0
|
540 zmemcpy(strm->next_out, strm->state->pending_out, len);
|
nuclear@0
|
541 strm->next_out += len;
|
nuclear@0
|
542 strm->state->pending_out += len;
|
nuclear@0
|
543 strm->total_out += len;
|
nuclear@0
|
544 strm->avail_out -= len;
|
nuclear@0
|
545 strm->state->pending -= len;
|
nuclear@0
|
546 if (strm->state->pending == 0) {
|
nuclear@0
|
547 strm->state->pending_out = strm->state->pending_buf;
|
nuclear@0
|
548 }
|
nuclear@0
|
549 }
|
nuclear@0
|
550
|
nuclear@0
|
551 /* ========================================================================= */
|
nuclear@0
|
552 int ZEXPORT deflate (strm, flush)
|
nuclear@0
|
553 z_streamp strm;
|
nuclear@0
|
554 int flush;
|
nuclear@0
|
555 {
|
nuclear@0
|
556 int old_flush; /* value of flush param for previous deflate call */
|
nuclear@0
|
557 deflate_state *s;
|
nuclear@0
|
558
|
nuclear@0
|
559 if (strm == Z_NULL || strm->state == Z_NULL ||
|
nuclear@0
|
560 flush > Z_FINISH || flush < 0) {
|
nuclear@0
|
561 return Z_STREAM_ERROR;
|
nuclear@0
|
562 }
|
nuclear@0
|
563 s = strm->state;
|
nuclear@0
|
564
|
nuclear@0
|
565 if (strm->next_out == Z_NULL ||
|
nuclear@0
|
566 (strm->next_in == Z_NULL && strm->avail_in != 0) ||
|
nuclear@0
|
567 (s->status == FINISH_STATE && flush != Z_FINISH)) {
|
nuclear@0
|
568 ERR_RETURN(strm, Z_STREAM_ERROR);
|
nuclear@0
|
569 }
|
nuclear@0
|
570 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
|
nuclear@0
|
571
|
nuclear@0
|
572 s->strm = strm; /* just in case */
|
nuclear@0
|
573 old_flush = s->last_flush;
|
nuclear@0
|
574 s->last_flush = flush;
|
nuclear@0
|
575
|
nuclear@0
|
576 /* Write the header */
|
nuclear@0
|
577 if (s->status == INIT_STATE) {
|
nuclear@0
|
578 #ifdef GZIP
|
nuclear@0
|
579 if (s->wrap == 2) {
|
nuclear@0
|
580 strm->adler = crc32(0L, Z_NULL, 0);
|
nuclear@0
|
581 put_byte(s, 31);
|
nuclear@0
|
582 put_byte(s, 139);
|
nuclear@0
|
583 put_byte(s, 8);
|
nuclear@0
|
584 if (s->gzhead == NULL) {
|
nuclear@0
|
585 put_byte(s, 0);
|
nuclear@0
|
586 put_byte(s, 0);
|
nuclear@0
|
587 put_byte(s, 0);
|
nuclear@0
|
588 put_byte(s, 0);
|
nuclear@0
|
589 put_byte(s, 0);
|
nuclear@0
|
590 put_byte(s, s->level == 9 ? 2 :
|
nuclear@0
|
591 (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
|
nuclear@0
|
592 4 : 0));
|
nuclear@0
|
593 put_byte(s, OS_CODE);
|
nuclear@0
|
594 s->status = BUSY_STATE;
|
nuclear@0
|
595 }
|
nuclear@0
|
596 else {
|
nuclear@0
|
597 put_byte(s, (s->gzhead->text ? 1 : 0) +
|
nuclear@0
|
598 (s->gzhead->hcrc ? 2 : 0) +
|
nuclear@0
|
599 (s->gzhead->extra == Z_NULL ? 0 : 4) +
|
nuclear@0
|
600 (s->gzhead->name == Z_NULL ? 0 : 8) +
|
nuclear@0
|
601 (s->gzhead->comment == Z_NULL ? 0 : 16)
|
nuclear@0
|
602 );
|
nuclear@0
|
603 put_byte(s, (Byte)(s->gzhead->time & 0xff));
|
nuclear@0
|
604 put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
|
nuclear@0
|
605 put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
|
nuclear@0
|
606 put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
|
nuclear@0
|
607 put_byte(s, s->level == 9 ? 2 :
|
nuclear@0
|
608 (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
|
nuclear@0
|
609 4 : 0));
|
nuclear@0
|
610 put_byte(s, s->gzhead->os & 0xff);
|
nuclear@0
|
611 if (s->gzhead->extra != NULL) {
|
nuclear@0
|
612 put_byte(s, s->gzhead->extra_len & 0xff);
|
nuclear@0
|
613 put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
|
nuclear@0
|
614 }
|
nuclear@0
|
615 if (s->gzhead->hcrc)
|
nuclear@0
|
616 strm->adler = crc32(strm->adler, s->pending_buf,
|
nuclear@0
|
617 s->pending);
|
nuclear@0
|
618 s->gzindex = 0;
|
nuclear@0
|
619 s->status = EXTRA_STATE;
|
nuclear@0
|
620 }
|
nuclear@0
|
621 }
|
nuclear@0
|
622 else
|
nuclear@0
|
623 #endif
|
nuclear@0
|
624 {
|
nuclear@0
|
625 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
|
nuclear@0
|
626 uInt level_flags;
|
nuclear@0
|
627
|
nuclear@0
|
628 if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
|
nuclear@0
|
629 level_flags = 0;
|
nuclear@0
|
630 else if (s->level < 6)
|
nuclear@0
|
631 level_flags = 1;
|
nuclear@0
|
632 else if (s->level == 6)
|
nuclear@0
|
633 level_flags = 2;
|
nuclear@0
|
634 else
|
nuclear@0
|
635 level_flags = 3;
|
nuclear@0
|
636 header |= (level_flags << 6);
|
nuclear@0
|
637 if (s->strstart != 0) header |= PRESET_DICT;
|
nuclear@0
|
638 header += 31 - (header % 31);
|
nuclear@0
|
639
|
nuclear@0
|
640 s->status = BUSY_STATE;
|
nuclear@0
|
641 putShortMSB(s, header);
|
nuclear@0
|
642
|
nuclear@0
|
643 /* Save the adler32 of the preset dictionary: */
|
nuclear@0
|
644 if (s->strstart != 0) {
|
nuclear@0
|
645 putShortMSB(s, (uInt)(strm->adler >> 16));
|
nuclear@0
|
646 putShortMSB(s, (uInt)(strm->adler & 0xffff));
|
nuclear@0
|
647 }
|
nuclear@0
|
648 strm->adler = adler32(0L, Z_NULL, 0);
|
nuclear@0
|
649 }
|
nuclear@0
|
650 }
|
nuclear@0
|
651 #ifdef GZIP
|
nuclear@0
|
652 if (s->status == EXTRA_STATE) {
|
nuclear@0
|
653 if (s->gzhead->extra != NULL) {
|
nuclear@0
|
654 uInt beg = s->pending; /* start of bytes to update crc */
|
nuclear@0
|
655
|
nuclear@0
|
656 while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {
|
nuclear@0
|
657 if (s->pending == s->pending_buf_size) {
|
nuclear@0
|
658 if (s->gzhead->hcrc && s->pending > beg)
|
nuclear@0
|
659 strm->adler = crc32(strm->adler, s->pending_buf + beg,
|
nuclear@0
|
660 s->pending - beg);
|
nuclear@0
|
661 flush_pending(strm);
|
nuclear@0
|
662 beg = s->pending;
|
nuclear@0
|
663 if (s->pending == s->pending_buf_size)
|
nuclear@0
|
664 break;
|
nuclear@0
|
665 }
|
nuclear@0
|
666 put_byte(s, s->gzhead->extra[s->gzindex]);
|
nuclear@0
|
667 s->gzindex++;
|
nuclear@0
|
668 }
|
nuclear@0
|
669 if (s->gzhead->hcrc && s->pending > beg)
|
nuclear@0
|
670 strm->adler = crc32(strm->adler, s->pending_buf + beg,
|
nuclear@0
|
671 s->pending - beg);
|
nuclear@0
|
672 if (s->gzindex == s->gzhead->extra_len) {
|
nuclear@0
|
673 s->gzindex = 0;
|
nuclear@0
|
674 s->status = NAME_STATE;
|
nuclear@0
|
675 }
|
nuclear@0
|
676 }
|
nuclear@0
|
677 else
|
nuclear@0
|
678 s->status = NAME_STATE;
|
nuclear@0
|
679 }
|
nuclear@0
|
680 if (s->status == NAME_STATE) {
|
nuclear@0
|
681 if (s->gzhead->name != NULL) {
|
nuclear@0
|
682 uInt beg = s->pending; /* start of bytes to update crc */
|
nuclear@0
|
683 int val;
|
nuclear@0
|
684
|
nuclear@0
|
685 do {
|
nuclear@0
|
686 if (s->pending == s->pending_buf_size) {
|
nuclear@0
|
687 if (s->gzhead->hcrc && s->pending > beg)
|
nuclear@0
|
688 strm->adler = crc32(strm->adler, s->pending_buf + beg,
|
nuclear@0
|
689 s->pending - beg);
|
nuclear@0
|
690 flush_pending(strm);
|
nuclear@0
|
691 beg = s->pending;
|
nuclear@0
|
692 if (s->pending == s->pending_buf_size) {
|
nuclear@0
|
693 val = 1;
|
nuclear@0
|
694 break;
|
nuclear@0
|
695 }
|
nuclear@0
|
696 }
|
nuclear@0
|
697 val = s->gzhead->name[s->gzindex++];
|
nuclear@0
|
698 put_byte(s, val);
|
nuclear@0
|
699 } while (val != 0);
|
nuclear@0
|
700 if (s->gzhead->hcrc && s->pending > beg)
|
nuclear@0
|
701 strm->adler = crc32(strm->adler, s->pending_buf + beg,
|
nuclear@0
|
702 s->pending - beg);
|
nuclear@0
|
703 if (val == 0) {
|
nuclear@0
|
704 s->gzindex = 0;
|
nuclear@0
|
705 s->status = COMMENT_STATE;
|
nuclear@0
|
706 }
|
nuclear@0
|
707 }
|
nuclear@0
|
708 else
|
nuclear@0
|
709 s->status = COMMENT_STATE;
|
nuclear@0
|
710 }
|
nuclear@0
|
711 if (s->status == COMMENT_STATE) {
|
nuclear@0
|
712 if (s->gzhead->comment != NULL) {
|
nuclear@0
|
713 uInt beg = s->pending; /* start of bytes to update crc */
|
nuclear@0
|
714 int val;
|
nuclear@0
|
715
|
nuclear@0
|
716 do {
|
nuclear@0
|
717 if (s->pending == s->pending_buf_size) {
|
nuclear@0
|
718 if (s->gzhead->hcrc && s->pending > beg)
|
nuclear@0
|
719 strm->adler = crc32(strm->adler, s->pending_buf + beg,
|
nuclear@0
|
720 s->pending - beg);
|
nuclear@0
|
721 flush_pending(strm);
|
nuclear@0
|
722 beg = s->pending;
|
nuclear@0
|
723 if (s->pending == s->pending_buf_size) {
|
nuclear@0
|
724 val = 1;
|
nuclear@0
|
725 break;
|
nuclear@0
|
726 }
|
nuclear@0
|
727 }
|
nuclear@0
|
728 val = s->gzhead->comment[s->gzindex++];
|
nuclear@0
|
729 put_byte(s, val);
|
nuclear@0
|
730 } while (val != 0);
|
nuclear@0
|
731 if (s->gzhead->hcrc && s->pending > beg)
|
nuclear@0
|
732 strm->adler = crc32(strm->adler, s->pending_buf + beg,
|
nuclear@0
|
733 s->pending - beg);
|
nuclear@0
|
734 if (val == 0)
|
nuclear@0
|
735 s->status = HCRC_STATE;
|
nuclear@0
|
736 }
|
nuclear@0
|
737 else
|
nuclear@0
|
738 s->status = HCRC_STATE;
|
nuclear@0
|
739 }
|
nuclear@0
|
740 if (s->status == HCRC_STATE) {
|
nuclear@0
|
741 if (s->gzhead->hcrc) {
|
nuclear@0
|
742 if (s->pending + 2 > s->pending_buf_size)
|
nuclear@0
|
743 flush_pending(strm);
|
nuclear@0
|
744 if (s->pending + 2 <= s->pending_buf_size) {
|
nuclear@0
|
745 put_byte(s, (Byte)(strm->adler & 0xff));
|
nuclear@0
|
746 put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
|
nuclear@0
|
747 strm->adler = crc32(0L, Z_NULL, 0);
|
nuclear@0
|
748 s->status = BUSY_STATE;
|
nuclear@0
|
749 }
|
nuclear@0
|
750 }
|
nuclear@0
|
751 else
|
nuclear@0
|
752 s->status = BUSY_STATE;
|
nuclear@0
|
753 }
|
nuclear@0
|
754 #endif
|
nuclear@0
|
755
|
nuclear@0
|
756 /* Flush as much pending output as possible */
|
nuclear@0
|
757 if (s->pending != 0) {
|
nuclear@0
|
758 flush_pending(strm);
|
nuclear@0
|
759 if (strm->avail_out == 0) {
|
nuclear@0
|
760 /* Since avail_out is 0, deflate will be called again with
|
nuclear@0
|
761 * more output space, but possibly with both pending and
|
nuclear@0
|
762 * avail_in equal to zero. There won't be anything to do,
|
nuclear@0
|
763 * but this is not an error situation so make sure we
|
nuclear@0
|
764 * return OK instead of BUF_ERROR at next call of deflate:
|
nuclear@0
|
765 */
|
nuclear@0
|
766 s->last_flush = -1;
|
nuclear@0
|
767 return Z_OK;
|
nuclear@0
|
768 }
|
nuclear@0
|
769
|
nuclear@0
|
770 /* Make sure there is something to do and avoid duplicate consecutive
|
nuclear@0
|
771 * flushes. For repeated and useless calls with Z_FINISH, we keep
|
nuclear@0
|
772 * returning Z_STREAM_END instead of Z_BUF_ERROR.
|
nuclear@0
|
773 */
|
nuclear@0
|
774 } else if (strm->avail_in == 0 && flush <= old_flush &&
|
nuclear@0
|
775 flush != Z_FINISH) {
|
nuclear@0
|
776 ERR_RETURN(strm, Z_BUF_ERROR);
|
nuclear@0
|
777 }
|
nuclear@0
|
778
|
nuclear@0
|
779 /* User must not provide more input after the first FINISH: */
|
nuclear@0
|
780 if (s->status == FINISH_STATE && strm->avail_in != 0) {
|
nuclear@0
|
781 ERR_RETURN(strm, Z_BUF_ERROR);
|
nuclear@0
|
782 }
|
nuclear@0
|
783
|
nuclear@0
|
784 /* Start a new block or continue the current one.
|
nuclear@0
|
785 */
|
nuclear@0
|
786 if (strm->avail_in != 0 || s->lookahead != 0 ||
|
nuclear@0
|
787 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
|
nuclear@0
|
788 block_state bstate;
|
nuclear@0
|
789
|
nuclear@0
|
790 bstate = (*(configuration_table[s->level].func))(s, flush);
|
nuclear@0
|
791
|
nuclear@0
|
792 if (bstate == finish_started || bstate == finish_done) {
|
nuclear@0
|
793 s->status = FINISH_STATE;
|
nuclear@0
|
794 }
|
nuclear@0
|
795 if (bstate == need_more || bstate == finish_started) {
|
nuclear@0
|
796 if (strm->avail_out == 0) {
|
nuclear@0
|
797 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
|
nuclear@0
|
798 }
|
nuclear@0
|
799 return Z_OK;
|
nuclear@0
|
800 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
|
nuclear@0
|
801 * of deflate should use the same flush parameter to make sure
|
nuclear@0
|
802 * that the flush is complete. So we don't have to output an
|
nuclear@0
|
803 * empty block here, this will be done at next call. This also
|
nuclear@0
|
804 * ensures that for a very small output buffer, we emit at most
|
nuclear@0
|
805 * one empty block.
|
nuclear@0
|
806 */
|
nuclear@0
|
807 }
|
nuclear@0
|
808 if (bstate == block_done) {
|
nuclear@0
|
809 if (flush == Z_PARTIAL_FLUSH) {
|
nuclear@0
|
810 _tr_align(s);
|
nuclear@0
|
811 } else { /* FULL_FLUSH or SYNC_FLUSH */
|
nuclear@0
|
812 _tr_stored_block(s, (char*)0, 0L, 0);
|
nuclear@0
|
813 /* For a full flush, this empty block will be recognized
|
nuclear@0
|
814 * as a special marker by inflate_sync().
|
nuclear@0
|
815 */
|
nuclear@0
|
816 if (flush == Z_FULL_FLUSH) {
|
nuclear@0
|
817 CLEAR_HASH(s); /* forget history */
|
nuclear@0
|
818 }
|
nuclear@0
|
819 }
|
nuclear@0
|
820 flush_pending(strm);
|
nuclear@0
|
821 if (strm->avail_out == 0) {
|
nuclear@0
|
822 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
|
nuclear@0
|
823 return Z_OK;
|
nuclear@0
|
824 }
|
nuclear@0
|
825 }
|
nuclear@0
|
826 }
|
nuclear@0
|
827 Assert(strm->avail_out > 0, "bug2");
|
nuclear@0
|
828
|
nuclear@0
|
829 if (flush != Z_FINISH) return Z_OK;
|
nuclear@0
|
830 if (s->wrap <= 0) return Z_STREAM_END;
|
nuclear@0
|
831
|
nuclear@0
|
832 /* Write the trailer */
|
nuclear@0
|
833 #ifdef GZIP
|
nuclear@0
|
834 if (s->wrap == 2) {
|
nuclear@0
|
835 put_byte(s, (Byte)(strm->adler & 0xff));
|
nuclear@0
|
836 put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
|
nuclear@0
|
837 put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
|
nuclear@0
|
838 put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
|
nuclear@0
|
839 put_byte(s, (Byte)(strm->total_in & 0xff));
|
nuclear@0
|
840 put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
|
nuclear@0
|
841 put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
|
nuclear@0
|
842 put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
|
nuclear@0
|
843 }
|
nuclear@0
|
844 else
|
nuclear@0
|
845 #endif
|
nuclear@0
|
846 {
|
nuclear@0
|
847 putShortMSB(s, (uInt)(strm->adler >> 16));
|
nuclear@0
|
848 putShortMSB(s, (uInt)(strm->adler & 0xffff));
|
nuclear@0
|
849 }
|
nuclear@0
|
850 flush_pending(strm);
|
nuclear@0
|
851 /* If avail_out is zero, the application will call deflate again
|
nuclear@0
|
852 * to flush the rest.
|
nuclear@0
|
853 */
|
nuclear@0
|
854 if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
|
nuclear@0
|
855 return s->pending != 0 ? Z_OK : Z_STREAM_END;
|
nuclear@0
|
856 }
|
nuclear@0
|
857
|
nuclear@0
|
858 /* ========================================================================= */
|
nuclear@0
|
859 int ZEXPORT deflateEnd (strm)
|
nuclear@0
|
860 z_streamp strm;
|
nuclear@0
|
861 {
|
nuclear@0
|
862 int status;
|
nuclear@0
|
863
|
nuclear@0
|
864 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
|
nuclear@0
|
865
|
nuclear@0
|
866 status = strm->state->status;
|
nuclear@0
|
867 if (status != INIT_STATE &&
|
nuclear@0
|
868 status != EXTRA_STATE &&
|
nuclear@0
|
869 status != NAME_STATE &&
|
nuclear@0
|
870 status != COMMENT_STATE &&
|
nuclear@0
|
871 status != HCRC_STATE &&
|
nuclear@0
|
872 status != BUSY_STATE &&
|
nuclear@0
|
873 status != FINISH_STATE) {
|
nuclear@0
|
874 return Z_STREAM_ERROR;
|
nuclear@0
|
875 }
|
nuclear@0
|
876
|
nuclear@0
|
877 /* Deallocate in reverse order of allocations: */
|
nuclear@0
|
878 TRY_FREE(strm, strm->state->pending_buf);
|
nuclear@0
|
879 TRY_FREE(strm, strm->state->head);
|
nuclear@0
|
880 TRY_FREE(strm, strm->state->prev);
|
nuclear@0
|
881 TRY_FREE(strm, strm->state->window);
|
nuclear@0
|
882
|
nuclear@0
|
883 ZFREE(strm, strm->state);
|
nuclear@0
|
884 strm->state = Z_NULL;
|
nuclear@0
|
885
|
nuclear@0
|
886 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
|
nuclear@0
|
887 }
|
nuclear@0
|
888
|
nuclear@0
|
889 /* =========================================================================
|
nuclear@0
|
890 * Copy the source state to the destination state.
|
nuclear@0
|
891 * To simplify the source, this is not supported for 16-bit MSDOS (which
|
nuclear@0
|
892 * doesn't have enough memory anyway to duplicate compression states).
|
nuclear@0
|
893 */
|
nuclear@0
|
894 int ZEXPORT deflateCopy (dest, source)
|
nuclear@0
|
895 z_streamp dest;
|
nuclear@0
|
896 z_streamp source;
|
nuclear@0
|
897 {
|
nuclear@0
|
898 #ifdef MAXSEG_64K
|
nuclear@0
|
899 return Z_STREAM_ERROR;
|
nuclear@0
|
900 #else
|
nuclear@0
|
901 deflate_state *ds;
|
nuclear@0
|
902 deflate_state *ss;
|
nuclear@0
|
903 ushf *overlay;
|
nuclear@0
|
904
|
nuclear@0
|
905
|
nuclear@0
|
906 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
|
nuclear@0
|
907 return Z_STREAM_ERROR;
|
nuclear@0
|
908 }
|
nuclear@0
|
909
|
nuclear@0
|
910 ss = source->state;
|
nuclear@0
|
911
|
nuclear@0
|
912 zmemcpy(dest, source, sizeof(z_stream));
|
nuclear@0
|
913
|
nuclear@0
|
914 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
|
nuclear@0
|
915 if (ds == Z_NULL) return Z_MEM_ERROR;
|
nuclear@0
|
916 dest->state = (struct internal_state FAR *) ds;
|
nuclear@0
|
917 zmemcpy(ds, ss, sizeof(deflate_state));
|
nuclear@0
|
918 ds->strm = dest;
|
nuclear@0
|
919
|
nuclear@0
|
920 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
|
nuclear@0
|
921 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
|
nuclear@0
|
922 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
|
nuclear@0
|
923 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
|
nuclear@0
|
924 ds->pending_buf = (uchf *) overlay;
|
nuclear@0
|
925
|
nuclear@0
|
926 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
|
nuclear@0
|
927 ds->pending_buf == Z_NULL) {
|
nuclear@0
|
928 deflateEnd (dest);
|
nuclear@0
|
929 return Z_MEM_ERROR;
|
nuclear@0
|
930 }
|
nuclear@0
|
931 /* following zmemcpy do not work for 16-bit MSDOS */
|
nuclear@0
|
932 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
|
nuclear@0
|
933 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
|
nuclear@0
|
934 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
|
nuclear@0
|
935 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
|
nuclear@0
|
936
|
nuclear@0
|
937 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
|
nuclear@0
|
938 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
|
nuclear@0
|
939 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
|
nuclear@0
|
940
|
nuclear@0
|
941 ds->l_desc.dyn_tree = ds->dyn_ltree;
|
nuclear@0
|
942 ds->d_desc.dyn_tree = ds->dyn_dtree;
|
nuclear@0
|
943 ds->bl_desc.dyn_tree = ds->bl_tree;
|
nuclear@0
|
944
|
nuclear@0
|
945 return Z_OK;
|
nuclear@0
|
946 #endif /* MAXSEG_64K */
|
nuclear@0
|
947 }
|
nuclear@0
|
948
|
nuclear@0
|
949 /* ===========================================================================
|
nuclear@0
|
950 * Read a new buffer from the current input stream, update the adler32
|
nuclear@0
|
951 * and total number of bytes read. All deflate() input goes through
|
nuclear@0
|
952 * this function so some applications may wish to modify it to avoid
|
nuclear@0
|
953 * allocating a large strm->next_in buffer and copying from it.
|
nuclear@0
|
954 * (See also flush_pending()).
|
nuclear@0
|
955 */
|
nuclear@0
|
956 local int read_buf(strm, buf, size)
|
nuclear@0
|
957 z_streamp strm;
|
nuclear@0
|
958 Bytef *buf;
|
nuclear@0
|
959 unsigned size;
|
nuclear@0
|
960 {
|
nuclear@0
|
961 unsigned len = strm->avail_in;
|
nuclear@0
|
962
|
nuclear@0
|
963 if (len > size) len = size;
|
nuclear@0
|
964 if (len == 0) return 0;
|
nuclear@0
|
965
|
nuclear@0
|
966 strm->avail_in -= len;
|
nuclear@0
|
967
|
nuclear@0
|
968 if (strm->state->wrap == 1) {
|
nuclear@0
|
969 strm->adler = adler32(strm->adler, strm->next_in, len);
|
nuclear@0
|
970 }
|
nuclear@0
|
971 #ifdef GZIP
|
nuclear@0
|
972 else if (strm->state->wrap == 2) {
|
nuclear@0
|
973 strm->adler = crc32(strm->adler, strm->next_in, len);
|
nuclear@0
|
974 }
|
nuclear@0
|
975 #endif
|
nuclear@0
|
976 zmemcpy(buf, strm->next_in, len);
|
nuclear@0
|
977 strm->next_in += len;
|
nuclear@0
|
978 strm->total_in += len;
|
nuclear@0
|
979
|
nuclear@0
|
980 return (int)len;
|
nuclear@0
|
981 }
|
nuclear@0
|
982
|
nuclear@0
|
983 /* ===========================================================================
|
nuclear@0
|
984 * Initialize the "longest match" routines for a new zlib stream
|
nuclear@0
|
985 */
|
nuclear@0
|
986 local void lm_init (s)
|
nuclear@0
|
987 deflate_state *s;
|
nuclear@0
|
988 {
|
nuclear@0
|
989 s->window_size = (ulg)2L*s->w_size;
|
nuclear@0
|
990
|
nuclear@0
|
991 CLEAR_HASH(s);
|
nuclear@0
|
992
|
nuclear@0
|
993 /* Set the default configuration parameters:
|
nuclear@0
|
994 */
|
nuclear@0
|
995 s->max_lazy_match = configuration_table[s->level].max_lazy;
|
nuclear@0
|
996 s->good_match = configuration_table[s->level].good_length;
|
nuclear@0
|
997 s->nice_match = configuration_table[s->level].nice_length;
|
nuclear@0
|
998 s->max_chain_length = configuration_table[s->level].max_chain;
|
nuclear@0
|
999
|
nuclear@0
|
1000 s->strstart = 0;
|
nuclear@0
|
1001 s->block_start = 0L;
|
nuclear@0
|
1002 s->lookahead = 0;
|
nuclear@0
|
1003 s->match_length = s->prev_length = MIN_MATCH-1;
|
nuclear@0
|
1004 s->match_available = 0;
|
nuclear@0
|
1005 s->ins_h = 0;
|
nuclear@0
|
1006 #ifndef FASTEST
|
nuclear@0
|
1007 #ifdef ASMV
|
nuclear@0
|
1008 match_init(); /* initialize the asm code */
|
nuclear@0
|
1009 #endif
|
nuclear@0
|
1010 #endif
|
nuclear@0
|
1011 }
|
nuclear@0
|
1012
|
nuclear@0
|
1013 #ifndef FASTEST
|
nuclear@0
|
1014 /* ===========================================================================
|
nuclear@0
|
1015 * Set match_start to the longest match starting at the given string and
|
nuclear@0
|
1016 * return its length. Matches shorter or equal to prev_length are discarded,
|
nuclear@0
|
1017 * in which case the result is equal to prev_length and match_start is
|
nuclear@0
|
1018 * garbage.
|
nuclear@0
|
1019 * IN assertions: cur_match is the head of the hash chain for the current
|
nuclear@0
|
1020 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
|
nuclear@0
|
1021 * OUT assertion: the match length is not greater than s->lookahead.
|
nuclear@0
|
1022 */
|
nuclear@0
|
1023 #ifndef ASMV
|
nuclear@0
|
1024 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
|
nuclear@0
|
1025 * match.S. The code will be functionally equivalent.
|
nuclear@0
|
1026 */
|
nuclear@0
|
1027 local uInt longest_match(s, cur_match)
|
nuclear@0
|
1028 deflate_state *s;
|
nuclear@0
|
1029 IPos cur_match; /* current match */
|
nuclear@0
|
1030 {
|
nuclear@0
|
1031 unsigned chain_length = s->max_chain_length;/* max hash chain length */
|
nuclear@0
|
1032 register Bytef *scan = s->window + s->strstart; /* current string */
|
nuclear@0
|
1033 register Bytef *match; /* matched string */
|
nuclear@0
|
1034 register int len; /* length of current match */
|
nuclear@0
|
1035 int best_len = s->prev_length; /* best match length so far */
|
nuclear@0
|
1036 int nice_match = s->nice_match; /* stop if match long enough */
|
nuclear@0
|
1037 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
|
nuclear@0
|
1038 s->strstart - (IPos)MAX_DIST(s) : NIL;
|
nuclear@0
|
1039 /* Stop when cur_match becomes <= limit. To simplify the code,
|
nuclear@0
|
1040 * we prevent matches with the string of window index 0.
|
nuclear@0
|
1041 */
|
nuclear@0
|
1042 Posf *prev = s->prev;
|
nuclear@0
|
1043 uInt wmask = s->w_mask;
|
nuclear@0
|
1044
|
nuclear@0
|
1045 #ifdef UNALIGNED_OK
|
nuclear@0
|
1046 /* Compare two bytes at a time. Note: this is not always beneficial.
|
nuclear@0
|
1047 * Try with and without -DUNALIGNED_OK to check.
|
nuclear@0
|
1048 */
|
nuclear@0
|
1049 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
|
nuclear@0
|
1050 register ush scan_start = *(ushf*)scan;
|
nuclear@0
|
1051 register ush scan_end = *(ushf*)(scan+best_len-1);
|
nuclear@0
|
1052 #else
|
nuclear@0
|
1053 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
|
nuclear@0
|
1054 register Byte scan_end1 = scan[best_len-1];
|
nuclear@0
|
1055 register Byte scan_end = scan[best_len];
|
nuclear@0
|
1056 #endif
|
nuclear@0
|
1057
|
nuclear@0
|
1058 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
|
nuclear@0
|
1059 * It is easy to get rid of this optimization if necessary.
|
nuclear@0
|
1060 */
|
nuclear@0
|
1061 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
|
nuclear@0
|
1062
|
nuclear@0
|
1063 /* Do not waste too much time if we already have a good match: */
|
nuclear@0
|
1064 if (s->prev_length >= s->good_match) {
|
nuclear@0
|
1065 chain_length >>= 2;
|
nuclear@0
|
1066 }
|
nuclear@0
|
1067 /* Do not look for matches beyond the end of the input. This is necessary
|
nuclear@0
|
1068 * to make deflate deterministic.
|
nuclear@0
|
1069 */
|
nuclear@0
|
1070 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
|
nuclear@0
|
1071
|
nuclear@0
|
1072 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
|
nuclear@0
|
1073
|
nuclear@0
|
1074 do {
|
nuclear@0
|
1075 Assert(cur_match < s->strstart, "no future");
|
nuclear@0
|
1076 match = s->window + cur_match;
|
nuclear@0
|
1077
|
nuclear@0
|
1078 /* Skip to next match if the match length cannot increase
|
nuclear@0
|
1079 * or if the match length is less than 2. Note that the checks below
|
nuclear@0
|
1080 * for insufficient lookahead only occur occasionally for performance
|
nuclear@0
|
1081 * reasons. Therefore uninitialized memory will be accessed, and
|
nuclear@0
|
1082 * conditional jumps will be made that depend on those values.
|
nuclear@0
|
1083 * However the length of the match is limited to the lookahead, so
|
nuclear@0
|
1084 * the output of deflate is not affected by the uninitialized values.
|
nuclear@0
|
1085 */
|
nuclear@0
|
1086 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
|
nuclear@0
|
1087 /* This code assumes sizeof(unsigned short) == 2. Do not use
|
nuclear@0
|
1088 * UNALIGNED_OK if your compiler uses a different size.
|
nuclear@0
|
1089 */
|
nuclear@0
|
1090 if (*(ushf*)(match+best_len-1) != scan_end ||
|
nuclear@0
|
1091 *(ushf*)match != scan_start) continue;
|
nuclear@0
|
1092
|
nuclear@0
|
1093 /* It is not necessary to compare scan[2] and match[2] since they are
|
nuclear@0
|
1094 * always equal when the other bytes match, given that the hash keys
|
nuclear@0
|
1095 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
|
nuclear@0
|
1096 * strstart+3, +5, ... up to strstart+257. We check for insufficient
|
nuclear@0
|
1097 * lookahead only every 4th comparison; the 128th check will be made
|
nuclear@0
|
1098 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
|
nuclear@0
|
1099 * necessary to put more guard bytes at the end of the window, or
|
nuclear@0
|
1100 * to check more often for insufficient lookahead.
|
nuclear@0
|
1101 */
|
nuclear@0
|
1102 Assert(scan[2] == match[2], "scan[2]?");
|
nuclear@0
|
1103 scan++, match++;
|
nuclear@0
|
1104 do {
|
nuclear@0
|
1105 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
|
nuclear@0
|
1106 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
|
nuclear@0
|
1107 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
|
nuclear@0
|
1108 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
|
nuclear@0
|
1109 scan < strend);
|
nuclear@0
|
1110 /* The funny "do {}" generates better code on most compilers */
|
nuclear@0
|
1111
|
nuclear@0
|
1112 /* Here, scan <= window+strstart+257 */
|
nuclear@0
|
1113 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
|
nuclear@0
|
1114 if (*scan == *match) scan++;
|
nuclear@0
|
1115
|
nuclear@0
|
1116 len = (MAX_MATCH - 1) - (int)(strend-scan);
|
nuclear@0
|
1117 scan = strend - (MAX_MATCH-1);
|
nuclear@0
|
1118
|
nuclear@0
|
1119 #else /* UNALIGNED_OK */
|
nuclear@0
|
1120
|
nuclear@0
|
1121 if (match[best_len] != scan_end ||
|
nuclear@0
|
1122 match[best_len-1] != scan_end1 ||
|
nuclear@0
|
1123 *match != *scan ||
|
nuclear@0
|
1124 *++match != scan[1]) continue;
|
nuclear@0
|
1125
|
nuclear@0
|
1126 /* The check at best_len-1 can be removed because it will be made
|
nuclear@0
|
1127 * again later. (This heuristic is not always a win.)
|
nuclear@0
|
1128 * It is not necessary to compare scan[2] and match[2] since they
|
nuclear@0
|
1129 * are always equal when the other bytes match, given that
|
nuclear@0
|
1130 * the hash keys are equal and that HASH_BITS >= 8.
|
nuclear@0
|
1131 */
|
nuclear@0
|
1132 scan += 2, match++;
|
nuclear@0
|
1133 Assert(*scan == *match, "match[2]?");
|
nuclear@0
|
1134
|
nuclear@0
|
1135 /* We check for insufficient lookahead only every 8th comparison;
|
nuclear@0
|
1136 * the 256th check will be made at strstart+258.
|
nuclear@0
|
1137 */
|
nuclear@0
|
1138 do {
|
nuclear@0
|
1139 } while (*++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1140 *++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1141 *++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1142 *++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1143 scan < strend);
|
nuclear@0
|
1144
|
nuclear@0
|
1145 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
|
nuclear@0
|
1146
|
nuclear@0
|
1147 len = MAX_MATCH - (int)(strend - scan);
|
nuclear@0
|
1148 scan = strend - MAX_MATCH;
|
nuclear@0
|
1149
|
nuclear@0
|
1150 #endif /* UNALIGNED_OK */
|
nuclear@0
|
1151
|
nuclear@0
|
1152 if (len > best_len) {
|
nuclear@0
|
1153 s->match_start = cur_match;
|
nuclear@0
|
1154 best_len = len;
|
nuclear@0
|
1155 if (len >= nice_match) break;
|
nuclear@0
|
1156 #ifdef UNALIGNED_OK
|
nuclear@0
|
1157 scan_end = *(ushf*)(scan+best_len-1);
|
nuclear@0
|
1158 #else
|
nuclear@0
|
1159 scan_end1 = scan[best_len-1];
|
nuclear@0
|
1160 scan_end = scan[best_len];
|
nuclear@0
|
1161 #endif
|
nuclear@0
|
1162 }
|
nuclear@0
|
1163 } while ((cur_match = prev[cur_match & wmask]) > limit
|
nuclear@0
|
1164 && --chain_length != 0);
|
nuclear@0
|
1165
|
nuclear@0
|
1166 if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
|
nuclear@0
|
1167 return s->lookahead;
|
nuclear@0
|
1168 }
|
nuclear@0
|
1169 #endif /* ASMV */
|
nuclear@0
|
1170 #endif /* FASTEST */
|
nuclear@0
|
1171
|
nuclear@0
|
1172 /* ---------------------------------------------------------------------------
|
nuclear@0
|
1173 * Optimized version for level == 1 or strategy == Z_RLE only
|
nuclear@0
|
1174 */
|
nuclear@0
|
1175 local uInt longest_match_fast(s, cur_match)
|
nuclear@0
|
1176 deflate_state *s;
|
nuclear@0
|
1177 IPos cur_match; /* current match */
|
nuclear@0
|
1178 {
|
nuclear@0
|
1179 register Bytef *scan = s->window + s->strstart; /* current string */
|
nuclear@0
|
1180 register Bytef *match; /* matched string */
|
nuclear@0
|
1181 register int len; /* length of current match */
|
nuclear@0
|
1182 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
|
nuclear@0
|
1183
|
nuclear@0
|
1184 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
|
nuclear@0
|
1185 * It is easy to get rid of this optimization if necessary.
|
nuclear@0
|
1186 */
|
nuclear@0
|
1187 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
|
nuclear@0
|
1188
|
nuclear@0
|
1189 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
|
nuclear@0
|
1190
|
nuclear@0
|
1191 Assert(cur_match < s->strstart, "no future");
|
nuclear@0
|
1192
|
nuclear@0
|
1193 match = s->window + cur_match;
|
nuclear@0
|
1194
|
nuclear@0
|
1195 /* Return failure if the match length is less than 2:
|
nuclear@0
|
1196 */
|
nuclear@0
|
1197 if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
|
nuclear@0
|
1198
|
nuclear@0
|
1199 /* The check at best_len-1 can be removed because it will be made
|
nuclear@0
|
1200 * again later. (This heuristic is not always a win.)
|
nuclear@0
|
1201 * It is not necessary to compare scan[2] and match[2] since they
|
nuclear@0
|
1202 * are always equal when the other bytes match, given that
|
nuclear@0
|
1203 * the hash keys are equal and that HASH_BITS >= 8.
|
nuclear@0
|
1204 */
|
nuclear@0
|
1205 scan += 2, match += 2;
|
nuclear@0
|
1206 Assert(*scan == *match, "match[2]?");
|
nuclear@0
|
1207
|
nuclear@0
|
1208 /* We check for insufficient lookahead only every 8th comparison;
|
nuclear@0
|
1209 * the 256th check will be made at strstart+258.
|
nuclear@0
|
1210 */
|
nuclear@0
|
1211 do {
|
nuclear@0
|
1212 } while (*++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1213 *++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1214 *++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1215 *++scan == *++match && *++scan == *++match &&
|
nuclear@0
|
1216 scan < strend);
|
nuclear@0
|
1217
|
nuclear@0
|
1218 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
|
nuclear@0
|
1219
|
nuclear@0
|
1220 len = MAX_MATCH - (int)(strend - scan);
|
nuclear@0
|
1221
|
nuclear@0
|
1222 if (len < MIN_MATCH) return MIN_MATCH - 1;
|
nuclear@0
|
1223
|
nuclear@0
|
1224 s->match_start = cur_match;
|
nuclear@0
|
1225 return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
|
nuclear@0
|
1226 }
|
nuclear@0
|
1227
|
nuclear@0
|
1228 #ifdef DEBUG
|
nuclear@0
|
1229 /* ===========================================================================
|
nuclear@0
|
1230 * Check that the match at match_start is indeed a match.
|
nuclear@0
|
1231 */
|
nuclear@0
|
1232 local void check_match(s, start, match, length)
|
nuclear@0
|
1233 deflate_state *s;
|
nuclear@0
|
1234 IPos start, match;
|
nuclear@0
|
1235 int length;
|
nuclear@0
|
1236 {
|
nuclear@0
|
1237 /* check that the match is indeed a match */
|
nuclear@0
|
1238 if (zmemcmp(s->window + match,
|
nuclear@0
|
1239 s->window + start, length) != EQUAL) {
|
nuclear@0
|
1240 fprintf(stderr, " start %u, match %u, length %d\n",
|
nuclear@0
|
1241 start, match, length);
|
nuclear@0
|
1242 do {
|
nuclear@0
|
1243 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
|
nuclear@0
|
1244 } while (--length != 0);
|
nuclear@0
|
1245 z_error("invalid match");
|
nuclear@0
|
1246 }
|
nuclear@0
|
1247 if (z_verbose > 1) {
|
nuclear@0
|
1248 fprintf(stderr,"\\[%d,%d]", start-match, length);
|
nuclear@0
|
1249 do { putc(s->window[start++], stderr); } while (--length != 0);
|
nuclear@0
|
1250 }
|
nuclear@0
|
1251 }
|
nuclear@0
|
1252 #else
|
nuclear@0
|
1253 # define check_match(s, start, match, length)
|
nuclear@0
|
1254 #endif /* DEBUG */
|
nuclear@0
|
1255
|
nuclear@0
|
1256 /* ===========================================================================
|
nuclear@0
|
1257 * Fill the window when the lookahead becomes insufficient.
|
nuclear@0
|
1258 * Updates strstart and lookahead.
|
nuclear@0
|
1259 *
|
nuclear@0
|
1260 * IN assertion: lookahead < MIN_LOOKAHEAD
|
nuclear@0
|
1261 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
|
nuclear@0
|
1262 * At least one byte has been read, or avail_in == 0; reads are
|
nuclear@0
|
1263 * performed for at least two bytes (required for the zip translate_eol
|
nuclear@0
|
1264 * option -- not supported here).
|
nuclear@0
|
1265 */
|
nuclear@0
|
1266 local void fill_window(s)
|
nuclear@0
|
1267 deflate_state *s;
|
nuclear@0
|
1268 {
|
nuclear@0
|
1269 register unsigned n, m;
|
nuclear@0
|
1270 register Posf *p;
|
nuclear@0
|
1271 unsigned more; /* Amount of free space at the end of the window. */
|
nuclear@0
|
1272 uInt wsize = s->w_size;
|
nuclear@0
|
1273
|
nuclear@0
|
1274 do {
|
nuclear@0
|
1275 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
|
nuclear@0
|
1276
|
nuclear@0
|
1277 /* Deal with !@#$% 64K limit: */
|
nuclear@0
|
1278 if (sizeof(int) <= 2) {
|
nuclear@0
|
1279 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
|
nuclear@0
|
1280 more = wsize;
|
nuclear@0
|
1281
|
nuclear@0
|
1282 } else if (more == (unsigned)(-1)) {
|
nuclear@0
|
1283 /* Very unlikely, but possible on 16 bit machine if
|
nuclear@0
|
1284 * strstart == 0 && lookahead == 1 (input done a byte at time)
|
nuclear@0
|
1285 */
|
nuclear@0
|
1286 more--;
|
nuclear@0
|
1287 }
|
nuclear@0
|
1288 }
|
nuclear@0
|
1289
|
nuclear@0
|
1290 /* If the window is almost full and there is insufficient lookahead,
|
nuclear@0
|
1291 * move the upper half to the lower one to make room in the upper half.
|
nuclear@0
|
1292 */
|
nuclear@0
|
1293 if (s->strstart >= wsize+MAX_DIST(s)) {
|
nuclear@0
|
1294
|
nuclear@0
|
1295 zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
|
nuclear@0
|
1296 s->match_start -= wsize;
|
nuclear@0
|
1297 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
|
nuclear@0
|
1298 s->block_start -= (long) wsize;
|
nuclear@0
|
1299
|
nuclear@0
|
1300 /* Slide the hash table (could be avoided with 32 bit values
|
nuclear@0
|
1301 at the expense of memory usage). We slide even when level == 0
|
nuclear@0
|
1302 to keep the hash table consistent if we switch back to level > 0
|
nuclear@0
|
1303 later. (Using level 0 permanently is not an optimal usage of
|
nuclear@0
|
1304 zlib, so we don't care about this pathological case.)
|
nuclear@0
|
1305 */
|
nuclear@0
|
1306 /* %%% avoid this when Z_RLE */
|
nuclear@0
|
1307 n = s->hash_size;
|
nuclear@0
|
1308 p = &s->head[n];
|
nuclear@0
|
1309 do {
|
nuclear@0
|
1310 m = *--p;
|
nuclear@0
|
1311 *p = (Pos)(m >= wsize ? m-wsize : NIL);
|
nuclear@0
|
1312 } while (--n);
|
nuclear@0
|
1313
|
nuclear@0
|
1314 n = wsize;
|
nuclear@0
|
1315 #ifndef FASTEST
|
nuclear@0
|
1316 p = &s->prev[n];
|
nuclear@0
|
1317 do {
|
nuclear@0
|
1318 m = *--p;
|
nuclear@0
|
1319 *p = (Pos)(m >= wsize ? m-wsize : NIL);
|
nuclear@0
|
1320 /* If n is not on any hash chain, prev[n] is garbage but
|
nuclear@0
|
1321 * its value will never be used.
|
nuclear@0
|
1322 */
|
nuclear@0
|
1323 } while (--n);
|
nuclear@0
|
1324 #endif
|
nuclear@0
|
1325 more += wsize;
|
nuclear@0
|
1326 }
|
nuclear@0
|
1327 if (s->strm->avail_in == 0) return;
|
nuclear@0
|
1328
|
nuclear@0
|
1329 /* If there was no sliding:
|
nuclear@0
|
1330 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
|
nuclear@0
|
1331 * more == window_size - lookahead - strstart
|
nuclear@0
|
1332 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
|
nuclear@0
|
1333 * => more >= window_size - 2*WSIZE + 2
|
nuclear@0
|
1334 * In the BIG_MEM or MMAP case (not yet supported),
|
nuclear@0
|
1335 * window_size == input_size + MIN_LOOKAHEAD &&
|
nuclear@0
|
1336 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
|
nuclear@0
|
1337 * Otherwise, window_size == 2*WSIZE so more >= 2.
|
nuclear@0
|
1338 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
|
nuclear@0
|
1339 */
|
nuclear@0
|
1340 Assert(more >= 2, "more < 2");
|
nuclear@0
|
1341
|
nuclear@0
|
1342 n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
|
nuclear@0
|
1343 s->lookahead += n;
|
nuclear@0
|
1344
|
nuclear@0
|
1345 /* Initialize the hash value now that we have some input: */
|
nuclear@0
|
1346 if (s->lookahead >= MIN_MATCH) {
|
nuclear@0
|
1347 s->ins_h = s->window[s->strstart];
|
nuclear@0
|
1348 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
|
nuclear@0
|
1349 #if MIN_MATCH != 3
|
nuclear@0
|
1350 Call UPDATE_HASH() MIN_MATCH-3 more times
|
nuclear@0
|
1351 #endif
|
nuclear@0
|
1352 }
|
nuclear@0
|
1353 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
|
nuclear@0
|
1354 * but this is not important since only literal bytes will be emitted.
|
nuclear@0
|
1355 */
|
nuclear@0
|
1356
|
nuclear@0
|
1357 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
|
nuclear@0
|
1358 }
|
nuclear@0
|
1359
|
nuclear@0
|
1360 /* ===========================================================================
|
nuclear@0
|
1361 * Flush the current block, with given end-of-file flag.
|
nuclear@0
|
1362 * IN assertion: strstart is set to the end of the current match.
|
nuclear@0
|
1363 */
|
nuclear@0
|
1364 #define FLUSH_BLOCK_ONLY(s, eof) { \
|
nuclear@0
|
1365 _tr_flush_block(s, (s->block_start >= 0L ? \
|
nuclear@0
|
1366 (charf *)&s->window[(unsigned)s->block_start] : \
|
nuclear@0
|
1367 (charf *)Z_NULL), \
|
nuclear@0
|
1368 (ulg)((long)s->strstart - s->block_start), \
|
nuclear@0
|
1369 (eof)); \
|
nuclear@0
|
1370 s->block_start = s->strstart; \
|
nuclear@0
|
1371 flush_pending(s->strm); \
|
nuclear@0
|
1372 Tracev((stderr,"[FLUSH]")); \
|
nuclear@0
|
1373 }
|
nuclear@0
|
1374
|
nuclear@0
|
1375 /* Same but force premature exit if necessary. */
|
nuclear@0
|
1376 #define FLUSH_BLOCK(s, eof) { \
|
nuclear@0
|
1377 FLUSH_BLOCK_ONLY(s, eof); \
|
nuclear@0
|
1378 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
|
nuclear@0
|
1379 }
|
nuclear@0
|
1380
|
nuclear@0
|
1381 /* ===========================================================================
|
nuclear@0
|
1382 * Copy without compression as much as possible from the input stream, return
|
nuclear@0
|
1383 * the current block state.
|
nuclear@0
|
1384 * This function does not insert new strings in the dictionary since
|
nuclear@0
|
1385 * uncompressible data is probably not useful. This function is used
|
nuclear@0
|
1386 * only for the level=0 compression option.
|
nuclear@0
|
1387 * NOTE: this function should be optimized to avoid extra copying from
|
nuclear@0
|
1388 * window to pending_buf.
|
nuclear@0
|
1389 */
|
nuclear@0
|
1390 local block_state deflate_stored(s, flush)
|
nuclear@0
|
1391 deflate_state *s;
|
nuclear@0
|
1392 int flush;
|
nuclear@0
|
1393 {
|
nuclear@0
|
1394 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
|
nuclear@0
|
1395 * to pending_buf_size, and each stored block has a 5 byte header:
|
nuclear@0
|
1396 */
|
nuclear@0
|
1397 ulg max_block_size = 0xffff;
|
nuclear@0
|
1398 ulg max_start;
|
nuclear@0
|
1399
|
nuclear@0
|
1400 if (max_block_size > s->pending_buf_size - 5) {
|
nuclear@0
|
1401 max_block_size = s->pending_buf_size - 5;
|
nuclear@0
|
1402 }
|
nuclear@0
|
1403
|
nuclear@0
|
1404 /* Copy as much as possible from input to output: */
|
nuclear@0
|
1405 for (;;) {
|
nuclear@0
|
1406 /* Fill the window as much as possible: */
|
nuclear@0
|
1407 if (s->lookahead <= 1) {
|
nuclear@0
|
1408
|
nuclear@0
|
1409 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
|
nuclear@0
|
1410 s->block_start >= (long)s->w_size, "slide too late");
|
nuclear@0
|
1411
|
nuclear@0
|
1412 fill_window(s);
|
nuclear@0
|
1413 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
|
nuclear@0
|
1414
|
nuclear@0
|
1415 if (s->lookahead == 0) break; /* flush the current block */
|
nuclear@0
|
1416 }
|
nuclear@0
|
1417 Assert(s->block_start >= 0L, "block gone");
|
nuclear@0
|
1418
|
nuclear@0
|
1419 s->strstart += s->lookahead;
|
nuclear@0
|
1420 s->lookahead = 0;
|
nuclear@0
|
1421
|
nuclear@0
|
1422 /* Emit a stored block if pending_buf will be full: */
|
nuclear@0
|
1423 max_start = s->block_start + max_block_size;
|
nuclear@0
|
1424 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
|
nuclear@0
|
1425 /* strstart == 0 is possible when wraparound on 16-bit machine */
|
nuclear@0
|
1426 s->lookahead = (uInt)(s->strstart - max_start);
|
nuclear@0
|
1427 s->strstart = (uInt)max_start;
|
nuclear@0
|
1428 FLUSH_BLOCK(s, 0);
|
nuclear@0
|
1429 }
|
nuclear@0
|
1430 /* Flush if we may have to slide, otherwise block_start may become
|
nuclear@0
|
1431 * negative and the data will be gone:
|
nuclear@0
|
1432 */
|
nuclear@0
|
1433 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
|
nuclear@0
|
1434 FLUSH_BLOCK(s, 0);
|
nuclear@0
|
1435 }
|
nuclear@0
|
1436 }
|
nuclear@0
|
1437 FLUSH_BLOCK(s, flush == Z_FINISH);
|
nuclear@0
|
1438 return flush == Z_FINISH ? finish_done : block_done;
|
nuclear@0
|
1439 }
|
nuclear@0
|
1440
|
nuclear@0
|
1441 /* ===========================================================================
|
nuclear@0
|
1442 * Compress as much as possible from the input stream, return the current
|
nuclear@0
|
1443 * block state.
|
nuclear@0
|
1444 * This function does not perform lazy evaluation of matches and inserts
|
nuclear@0
|
1445 * new strings in the dictionary only for unmatched strings or for short
|
nuclear@0
|
1446 * matches. It is used only for the fast compression options.
|
nuclear@0
|
1447 */
|
nuclear@0
|
1448 local block_state deflate_fast(s, flush)
|
nuclear@0
|
1449 deflate_state *s;
|
nuclear@0
|
1450 int flush;
|
nuclear@0
|
1451 {
|
nuclear@0
|
1452 IPos hash_head = NIL; /* head of the hash chain */
|
nuclear@0
|
1453 int bflush; /* set if current block must be flushed */
|
nuclear@0
|
1454
|
nuclear@0
|
1455 for (;;) {
|
nuclear@0
|
1456 /* Make sure that we always have enough lookahead, except
|
nuclear@0
|
1457 * at the end of the input file. We need MAX_MATCH bytes
|
nuclear@0
|
1458 * for the next match, plus MIN_MATCH bytes to insert the
|
nuclear@0
|
1459 * string following the next match.
|
nuclear@0
|
1460 */
|
nuclear@0
|
1461 if (s->lookahead < MIN_LOOKAHEAD) {
|
nuclear@0
|
1462 fill_window(s);
|
nuclear@0
|
1463 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
|
nuclear@0
|
1464 return need_more;
|
nuclear@0
|
1465 }
|
nuclear@0
|
1466 if (s->lookahead == 0) break; /* flush the current block */
|
nuclear@0
|
1467 }
|
nuclear@0
|
1468
|
nuclear@0
|
1469 /* Insert the string window[strstart .. strstart+2] in the
|
nuclear@0
|
1470 * dictionary, and set hash_head to the head of the hash chain:
|
nuclear@0
|
1471 */
|
nuclear@0
|
1472 if (s->lookahead >= MIN_MATCH) {
|
nuclear@0
|
1473 INSERT_STRING(s, s->strstart, hash_head);
|
nuclear@0
|
1474 }
|
nuclear@0
|
1475
|
nuclear@0
|
1476 /* Find the longest match, discarding those <= prev_length.
|
nuclear@0
|
1477 * At this point we have always match_length < MIN_MATCH
|
nuclear@0
|
1478 */
|
nuclear@0
|
1479 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
|
nuclear@0
|
1480 /* To simplify the code, we prevent matches with the string
|
nuclear@0
|
1481 * of window index 0 (in particular we have to avoid a match
|
nuclear@0
|
1482 * of the string with itself at the start of the input file).
|
nuclear@0
|
1483 */
|
nuclear@0
|
1484 #ifdef FASTEST
|
nuclear@0
|
1485 if ((s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) ||
|
nuclear@0
|
1486 (s->strategy == Z_RLE && s->strstart - hash_head == 1)) {
|
nuclear@0
|
1487 s->match_length = longest_match_fast (s, hash_head);
|
nuclear@0
|
1488 }
|
nuclear@0
|
1489 #else
|
nuclear@0
|
1490 if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) {
|
nuclear@0
|
1491 s->match_length = longest_match (s, hash_head);
|
nuclear@0
|
1492 } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) {
|
nuclear@0
|
1493 s->match_length = longest_match_fast (s, hash_head);
|
nuclear@0
|
1494 }
|
nuclear@0
|
1495 #endif
|
nuclear@0
|
1496 /* longest_match() or longest_match_fast() sets match_start */
|
nuclear@0
|
1497 }
|
nuclear@0
|
1498 if (s->match_length >= MIN_MATCH) {
|
nuclear@0
|
1499 check_match(s, s->strstart, s->match_start, s->match_length);
|
nuclear@0
|
1500
|
nuclear@0
|
1501 _tr_tally_dist(s, s->strstart - s->match_start,
|
nuclear@0
|
1502 s->match_length - MIN_MATCH, bflush);
|
nuclear@0
|
1503
|
nuclear@0
|
1504 s->lookahead -= s->match_length;
|
nuclear@0
|
1505
|
nuclear@0
|
1506 /* Insert new strings in the hash table only if the match length
|
nuclear@0
|
1507 * is not too large. This saves time but degrades compression.
|
nuclear@0
|
1508 */
|
nuclear@0
|
1509 #ifndef FASTEST
|
nuclear@0
|
1510 if (s->match_length <= s->max_insert_length &&
|
nuclear@0
|
1511 s->lookahead >= MIN_MATCH) {
|
nuclear@0
|
1512 s->match_length--; /* string at strstart already in table */
|
nuclear@0
|
1513 do {
|
nuclear@0
|
1514 s->strstart++;
|
nuclear@0
|
1515 INSERT_STRING(s, s->strstart, hash_head);
|
nuclear@0
|
1516 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
|
nuclear@0
|
1517 * always MIN_MATCH bytes ahead.
|
nuclear@0
|
1518 */
|
nuclear@0
|
1519 } while (--s->match_length != 0);
|
nuclear@0
|
1520 s->strstart++;
|
nuclear@0
|
1521 } else
|
nuclear@0
|
1522 #endif
|
nuclear@0
|
1523 {
|
nuclear@0
|
1524 s->strstart += s->match_length;
|
nuclear@0
|
1525 s->match_length = 0;
|
nuclear@0
|
1526 s->ins_h = s->window[s->strstart];
|
nuclear@0
|
1527 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
|
nuclear@0
|
1528 #if MIN_MATCH != 3
|
nuclear@0
|
1529 Call UPDATE_HASH() MIN_MATCH-3 more times
|
nuclear@0
|
1530 #endif
|
nuclear@0
|
1531 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
|
nuclear@0
|
1532 * matter since it will be recomputed at next deflate call.
|
nuclear@0
|
1533 */
|
nuclear@0
|
1534 }
|
nuclear@0
|
1535 } else {
|
nuclear@0
|
1536 /* No match, output a literal byte */
|
nuclear@0
|
1537 Tracevv((stderr,"%c", s->window[s->strstart]));
|
nuclear@0
|
1538 _tr_tally_lit (s, s->window[s->strstart], bflush);
|
nuclear@0
|
1539 s->lookahead--;
|
nuclear@0
|
1540 s->strstart++;
|
nuclear@0
|
1541 }
|
nuclear@0
|
1542 if (bflush) FLUSH_BLOCK(s, 0);
|
nuclear@0
|
1543 }
|
nuclear@0
|
1544 FLUSH_BLOCK(s, flush == Z_FINISH);
|
nuclear@0
|
1545 return flush == Z_FINISH ? finish_done : block_done;
|
nuclear@0
|
1546 }
|
nuclear@0
|
1547
|
nuclear@0
|
1548 #ifndef FASTEST
|
nuclear@0
|
1549 /* ===========================================================================
|
nuclear@0
|
1550 * Same as above, but achieves better compression. We use a lazy
|
nuclear@0
|
1551 * evaluation for matches: a match is finally adopted only if there is
|
nuclear@0
|
1552 * no better match at the next window position.
|
nuclear@0
|
1553 */
|
nuclear@0
|
1554 local block_state deflate_slow(s, flush)
|
nuclear@0
|
1555 deflate_state *s;
|
nuclear@0
|
1556 int flush;
|
nuclear@0
|
1557 {
|
nuclear@0
|
1558 IPos hash_head = NIL; /* head of hash chain */
|
nuclear@0
|
1559 int bflush; /* set if current block must be flushed */
|
nuclear@0
|
1560
|
nuclear@0
|
1561 /* Process the input block. */
|
nuclear@0
|
1562 for (;;) {
|
nuclear@0
|
1563 /* Make sure that we always have enough lookahead, except
|
nuclear@0
|
1564 * at the end of the input file. We need MAX_MATCH bytes
|
nuclear@0
|
1565 * for the next match, plus MIN_MATCH bytes to insert the
|
nuclear@0
|
1566 * string following the next match.
|
nuclear@0
|
1567 */
|
nuclear@0
|
1568 if (s->lookahead < MIN_LOOKAHEAD) {
|
nuclear@0
|
1569 fill_window(s);
|
nuclear@0
|
1570 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
|
nuclear@0
|
1571 return need_more;
|
nuclear@0
|
1572 }
|
nuclear@0
|
1573 if (s->lookahead == 0) break; /* flush the current block */
|
nuclear@0
|
1574 }
|
nuclear@0
|
1575
|
nuclear@0
|
1576 /* Insert the string window[strstart .. strstart+2] in the
|
nuclear@0
|
1577 * dictionary, and set hash_head to the head of the hash chain:
|
nuclear@0
|
1578 */
|
nuclear@0
|
1579 if (s->lookahead >= MIN_MATCH) {
|
nuclear@0
|
1580 INSERT_STRING(s, s->strstart, hash_head);
|
nuclear@0
|
1581 }
|
nuclear@0
|
1582
|
nuclear@0
|
1583 /* Find the longest match, discarding those <= prev_length.
|
nuclear@0
|
1584 */
|
nuclear@0
|
1585 s->prev_length = s->match_length, s->prev_match = s->match_start;
|
nuclear@0
|
1586 s->match_length = MIN_MATCH-1;
|
nuclear@0
|
1587
|
nuclear@0
|
1588 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
|
nuclear@0
|
1589 s->strstart - hash_head <= MAX_DIST(s)) {
|
nuclear@0
|
1590 /* To simplify the code, we prevent matches with the string
|
nuclear@0
|
1591 * of window index 0 (in particular we have to avoid a match
|
nuclear@0
|
1592 * of the string with itself at the start of the input file).
|
nuclear@0
|
1593 */
|
nuclear@0
|
1594 if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) {
|
nuclear@0
|
1595 s->match_length = longest_match (s, hash_head);
|
nuclear@0
|
1596 } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) {
|
nuclear@0
|
1597 s->match_length = longest_match_fast (s, hash_head);
|
nuclear@0
|
1598 }
|
nuclear@0
|
1599 /* longest_match() or longest_match_fast() sets match_start */
|
nuclear@0
|
1600
|
nuclear@0
|
1601 if (s->match_length <= 5 && (s->strategy == Z_FILTERED
|
nuclear@0
|
1602 #if TOO_FAR <= 32767
|
nuclear@0
|
1603 || (s->match_length == MIN_MATCH &&
|
nuclear@0
|
1604 s->strstart - s->match_start > TOO_FAR)
|
nuclear@0
|
1605 #endif
|
nuclear@0
|
1606 )) {
|
nuclear@0
|
1607
|
nuclear@0
|
1608 /* If prev_match is also MIN_MATCH, match_start is garbage
|
nuclear@0
|
1609 * but we will ignore the current match anyway.
|
nuclear@0
|
1610 */
|
nuclear@0
|
1611 s->match_length = MIN_MATCH-1;
|
nuclear@0
|
1612 }
|
nuclear@0
|
1613 }
|
nuclear@0
|
1614 /* If there was a match at the previous step and the current
|
nuclear@0
|
1615 * match is not better, output the previous match:
|
nuclear@0
|
1616 */
|
nuclear@0
|
1617 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
|
nuclear@0
|
1618 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
|
nuclear@0
|
1619 /* Do not insert strings in hash table beyond this. */
|
nuclear@0
|
1620
|
nuclear@0
|
1621 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
|
nuclear@0
|
1622
|
nuclear@0
|
1623 _tr_tally_dist(s, s->strstart -1 - s->prev_match,
|
nuclear@0
|
1624 s->prev_length - MIN_MATCH, bflush);
|
nuclear@0
|
1625
|
nuclear@0
|
1626 /* Insert in hash table all strings up to the end of the match.
|
nuclear@0
|
1627 * strstart-1 and strstart are already inserted. If there is not
|
nuclear@0
|
1628 * enough lookahead, the last two strings are not inserted in
|
nuclear@0
|
1629 * the hash table.
|
nuclear@0
|
1630 */
|
nuclear@0
|
1631 s->lookahead -= s->prev_length-1;
|
nuclear@0
|
1632 s->prev_length -= 2;
|
nuclear@0
|
1633 do {
|
nuclear@0
|
1634 if (++s->strstart <= max_insert) {
|
nuclear@0
|
1635 INSERT_STRING(s, s->strstart, hash_head);
|
nuclear@0
|
1636 }
|
nuclear@0
|
1637 } while (--s->prev_length != 0);
|
nuclear@0
|
1638 s->match_available = 0;
|
nuclear@0
|
1639 s->match_length = MIN_MATCH-1;
|
nuclear@0
|
1640 s->strstart++;
|
nuclear@0
|
1641
|
nuclear@0
|
1642 if (bflush) FLUSH_BLOCK(s, 0);
|
nuclear@0
|
1643
|
nuclear@0
|
1644 } else if (s->match_available) {
|
nuclear@0
|
1645 /* If there was no match at the previous position, output a
|
nuclear@0
|
1646 * single literal. If there was a match but the current match
|
nuclear@0
|
1647 * is longer, truncate the previous match to a single literal.
|
nuclear@0
|
1648 */
|
nuclear@0
|
1649 Tracevv((stderr,"%c", s->window[s->strstart-1]));
|
nuclear@0
|
1650 _tr_tally_lit(s, s->window[s->strstart-1], bflush);
|
nuclear@0
|
1651 if (bflush) {
|
nuclear@0
|
1652 FLUSH_BLOCK_ONLY(s, 0);
|
nuclear@0
|
1653 }
|
nuclear@0
|
1654 s->strstart++;
|
nuclear@0
|
1655 s->lookahead--;
|
nuclear@0
|
1656 if (s->strm->avail_out == 0) return need_more;
|
nuclear@0
|
1657 } else {
|
nuclear@0
|
1658 /* There is no previous match to compare with, wait for
|
nuclear@0
|
1659 * the next step to decide.
|
nuclear@0
|
1660 */
|
nuclear@0
|
1661 s->match_available = 1;
|
nuclear@0
|
1662 s->strstart++;
|
nuclear@0
|
1663 s->lookahead--;
|
nuclear@0
|
1664 }
|
nuclear@0
|
1665 }
|
nuclear@0
|
1666 Assert (flush != Z_NO_FLUSH, "no flush?");
|
nuclear@0
|
1667 if (s->match_available) {
|
nuclear@0
|
1668 Tracevv((stderr,"%c", s->window[s->strstart-1]));
|
nuclear@0
|
1669 _tr_tally_lit(s, s->window[s->strstart-1], bflush);
|
nuclear@0
|
1670 s->match_available = 0;
|
nuclear@0
|
1671 }
|
nuclear@0
|
1672 FLUSH_BLOCK(s, flush == Z_FINISH);
|
nuclear@0
|
1673 return flush == Z_FINISH ? finish_done : block_done;
|
nuclear@0
|
1674 }
|
nuclear@0
|
1675 #endif /* FASTEST */
|
nuclear@0
|
1676
|
nuclear@0
|
1677 #if 0
|
nuclear@0
|
1678 /* ===========================================================================
|
nuclear@0
|
1679 * For Z_RLE, simply look for runs of bytes, generate matches only of distance
|
nuclear@0
|
1680 * one. Do not maintain a hash table. (It will be regenerated if this run of
|
nuclear@0
|
1681 * deflate switches away from Z_RLE.)
|
nuclear@0
|
1682 */
|
nuclear@0
|
1683 local block_state deflate_rle(s, flush)
|
nuclear@0
|
1684 deflate_state *s;
|
nuclear@0
|
1685 int flush;
|
nuclear@0
|
1686 {
|
nuclear@0
|
1687 int bflush; /* set if current block must be flushed */
|
nuclear@0
|
1688 uInt run; /* length of run */
|
nuclear@0
|
1689 uInt max; /* maximum length of run */
|
nuclear@0
|
1690 uInt prev; /* byte at distance one to match */
|
nuclear@0
|
1691 Bytef *scan; /* scan for end of run */
|
nuclear@0
|
1692
|
nuclear@0
|
1693 for (;;) {
|
nuclear@0
|
1694 /* Make sure that we always have enough lookahead, except
|
nuclear@0
|
1695 * at the end of the input file. We need MAX_MATCH bytes
|
nuclear@0
|
1696 * for the longest encodable run.
|
nuclear@0
|
1697 */
|
nuclear@0
|
1698 if (s->lookahead < MAX_MATCH) {
|
nuclear@0
|
1699 fill_window(s);
|
nuclear@0
|
1700 if (s->lookahead < MAX_MATCH && flush == Z_NO_FLUSH) {
|
nuclear@0
|
1701 return need_more;
|
nuclear@0
|
1702 }
|
nuclear@0
|
1703 if (s->lookahead == 0) break; /* flush the current block */
|
nuclear@0
|
1704 }
|
nuclear@0
|
1705
|
nuclear@0
|
1706 /* See how many times the previous byte repeats */
|
nuclear@0
|
1707 run = 0;
|
nuclear@0
|
1708 if (s->strstart > 0) { /* if there is a previous byte, that is */
|
nuclear@0
|
1709 max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH;
|
nuclear@0
|
1710 scan = s->window + s->strstart - 1;
|
nuclear@0
|
1711 prev = *scan++;
|
nuclear@0
|
1712 do {
|
nuclear@0
|
1713 if (*scan++ != prev)
|
nuclear@0
|
1714 break;
|
nuclear@0
|
1715 } while (++run < max);
|
nuclear@0
|
1716 }
|
nuclear@0
|
1717
|
nuclear@0
|
1718 /* Emit match if have run of MIN_MATCH or longer, else emit literal */
|
nuclear@0
|
1719 if (run >= MIN_MATCH) {
|
nuclear@0
|
1720 check_match(s, s->strstart, s->strstart - 1, run);
|
nuclear@0
|
1721 _tr_tally_dist(s, 1, run - MIN_MATCH, bflush);
|
nuclear@0
|
1722 s->lookahead -= run;
|
nuclear@0
|
1723 s->strstart += run;
|
nuclear@0
|
1724 } else {
|
nuclear@0
|
1725 /* No match, output a literal byte */
|
nuclear@0
|
1726 Tracevv((stderr,"%c", s->window[s->strstart]));
|
nuclear@0
|
1727 _tr_tally_lit (s, s->window[s->strstart], bflush);
|
nuclear@0
|
1728 s->lookahead--;
|
nuclear@0
|
1729 s->strstart++;
|
nuclear@0
|
1730 }
|
nuclear@0
|
1731 if (bflush) FLUSH_BLOCK(s, 0);
|
nuclear@0
|
1732 }
|
nuclear@0
|
1733 FLUSH_BLOCK(s, flush == Z_FINISH);
|
nuclear@0
|
1734 return flush == Z_FINISH ? finish_done : block_done;
|
nuclear@0
|
1735 }
|
nuclear@0
|
1736 #endif
|