1 | /* inflate.c -- zlib decompression |
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2 | * Copyright (C) 1995-2010 Mark Adler |
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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 | * Change history: |
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8 | * |
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9 | * 1.2.beta0 24 Nov 2002 |
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10 | * - First version -- complete rewrite of inflate to simplify code, avoid |
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11 | * creation of window when not needed, minimize use of window when it is |
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12 | * needed, make inffast.c even faster, implement gzip decoding, and to |
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13 | * improve code readability and style over the previous zlib inflate code |
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14 | * |
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15 | * 1.2.beta1 25 Nov 2002 |
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16 | * - Use pointers for available input and output checking in inffast.c |
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17 | * - Remove input and output counters in inffast.c |
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18 | * - Change inffast.c entry and loop from avail_in >= 7 to >= 6 |
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19 | * - Remove unnecessary second byte pull from length extra in inffast.c |
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20 | * - Unroll direct copy to three copies per loop in inffast.c |
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21 | * |
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22 | * 1.2.beta2 4 Dec 2002 |
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23 | * - Change external routine names to reduce potential conflicts |
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24 | * - Correct filename to inffixed.h for fixed tables in inflate.c |
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25 | * - Make hbuf[] unsigned char to match parameter type in inflate.c |
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26 | * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset) |
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27 | * to avoid negation problem on Alphas (64 bit) in inflate.c |
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28 | * |
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29 | * 1.2.beta3 22 Dec 2002 |
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30 | * - Add comments on state->bits assertion in inffast.c |
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31 | * - Add comments on op field in inftrees.h |
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32 | * - Fix bug in reuse of allocated window after inflateReset() |
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33 | * - Remove bit fields--back to byte structure for speed |
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34 | * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths |
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35 | * - Change post-increments to pre-increments in inflate_fast(), PPC biased? |
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36 | * - Add compile time option, POSTINC, to use post-increments instead (Intel?) |
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37 | * - Make MATCH copy in inflate() much faster for when inflate_fast() not used |
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38 | * - Use local copies of stream next and avail values, as well as local bit |
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39 | * buffer and bit count in inflate()--for speed when inflate_fast() not used |
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40 | * |
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41 | * 1.2.beta4 1 Jan 2003 |
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42 | * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings |
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43 | * - Move a comment on output buffer sizes from inffast.c to inflate.c |
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44 | * - Add comments in inffast.c to introduce the inflate_fast() routine |
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45 | * - Rearrange window copies in inflate_fast() for speed and simplification |
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46 | * - Unroll last copy for window match in inflate_fast() |
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47 | * - Use local copies of window variables in inflate_fast() for speed |
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48 | * - Pull out common wnext == 0 case for speed in inflate_fast() |
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49 | * - Make op and len in inflate_fast() unsigned for consistency |
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50 | * - Add FAR to lcode and dcode declarations in inflate_fast() |
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51 | * - Simplified bad distance check in inflate_fast() |
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52 | * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new |
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53 | * source file infback.c to provide a call-back interface to inflate for |
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54 | * programs like gzip and unzip -- uses window as output buffer to avoid |
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55 | * window copying |
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56 | * |
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57 | * 1.2.beta5 1 Jan 2003 |
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58 | * - Improved inflateBack() interface to allow the caller to provide initial |
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59 | * input in strm. |
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60 | * - Fixed stored blocks bug in inflateBack() |
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61 | * |
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62 | * 1.2.beta6 4 Jan 2003 |
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63 | * - Added comments in inffast.c on effectiveness of POSTINC |
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64 | * - Typecasting all around to reduce compiler warnings |
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65 | * - Changed loops from while (1) or do {} while (1) to for (;;), again to |
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66 | * make compilers happy |
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67 | * - Changed type of window in inflateBackInit() to unsigned char * |
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68 | * |
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69 | * 1.2.beta7 27 Jan 2003 |
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70 | * - Changed many types to unsigned or unsigned short to avoid warnings |
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71 | * - Added inflateCopy() function |
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72 | * |
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73 | * 1.2.0 9 Mar 2003 |
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74 | * - Changed inflateBack() interface to provide separate opaque descriptors |
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75 | * for the in() and out() functions |
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76 | * - Changed inflateBack() argument and in_func typedef to swap the length |
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77 | * and buffer address return values for the input function |
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78 | * - Check next_in and next_out for Z_NULL on entry to inflate() |
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79 | * |
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80 | * The history for versions after 1.2.0 are in ChangeLog in zlib distribution. |
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81 | */ |
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82 | |
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83 | #include "zutil.h" |
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84 | #include "inftrees.h" |
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85 | #include "inflate.h" |
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86 | #include "inffast.h" |
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87 | |
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88 | #ifdef MAKEFIXED |
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89 | # ifndef BUILDFIXED |
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90 | # define BUILDFIXED |
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91 | # endif |
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92 | #endif |
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93 | |
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94 | /* function prototypes */ |
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95 | local void fixedtables OF((struct inflate_state FAR *state)); |
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96 | local int updatewindow OF((z_streamp strm, unsigned out)); |
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97 | #ifdef BUILDFIXED |
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98 | void makefixed OF((void)); |
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99 | #endif |
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100 | local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf, |
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101 | unsigned len)); |
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102 | |
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103 | int ZEXPORT inflateReset(strm) |
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104 | z_streamp strm; |
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105 | { |
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106 | struct inflate_state FAR *state; |
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107 | |
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108 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
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109 | state = (struct inflate_state FAR *)strm->state; |
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110 | strm->total_in = strm->total_out = state->total = 0; |
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111 | strm->msg = Z_NULL; |
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112 | strm->adler = 1; /* to support ill-conceived Java test suite */ |
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113 | state->mode = HEAD; |
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114 | state->last = 0; |
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115 | state->havedict = 0; |
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116 | state->dmax = 32768U; |
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117 | state->head = Z_NULL; |
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118 | state->wsize = 0; |
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119 | state->whave = 0; |
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120 | state->wnext = 0; |
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121 | state->hold = 0; |
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122 | state->bits = 0; |
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123 | state->lencode = state->distcode = state->next = state->codes; |
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124 | state->sane = 1; |
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125 | state->back = -1; |
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126 | Tracev((stderr, "inflate: reset\n")); |
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127 | return Z_OK; |
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128 | } |
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129 | |
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130 | int ZEXPORT inflateReset2(strm, windowBits) |
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131 | z_streamp strm; |
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132 | int windowBits; |
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133 | { |
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134 | int wrap; |
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135 | struct inflate_state FAR *state; |
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136 | |
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137 | /* get the state */ |
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138 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
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139 | state = (struct inflate_state FAR *)strm->state; |
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140 | |
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141 | /* extract wrap request from windowBits parameter */ |
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142 | if (windowBits < 0) { |
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143 | wrap = 0; |
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144 | windowBits = -windowBits; |
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145 | } |
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146 | else { |
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147 | wrap = (windowBits >> 4) + 1; |
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148 | #ifdef GUNZIP |
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149 | if (windowBits < 48) |
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150 | windowBits &= 15; |
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151 | #endif |
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152 | } |
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153 | |
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154 | /* set number of window bits, free window if different */ |
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155 | if (windowBits && (windowBits < 8 || windowBits > 15)) |
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156 | return Z_STREAM_ERROR; |
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157 | if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) { |
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158 | ZFREE(strm, state->window); |
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159 | state->window = Z_NULL; |
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160 | } |
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161 | |
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162 | /* update state and reset the rest of it */ |
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163 | state->wrap = wrap; |
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164 | state->wbits = (unsigned)windowBits; |
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165 | return inflateReset(strm); |
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166 | } |
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167 | |
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168 | int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size) |
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169 | z_streamp strm; |
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170 | int windowBits; |
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171 | const char *version; |
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172 | int stream_size; |
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173 | { |
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174 | int ret; |
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175 | struct inflate_state FAR *state; |
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176 | |
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177 | if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || |
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178 | stream_size != (int)(sizeof(z_stream))) |
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179 | return Z_VERSION_ERROR; |
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180 | if (strm == Z_NULL) return Z_STREAM_ERROR; |
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181 | strm->msg = Z_NULL; /* in case we return an error */ |
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182 | if (strm->zalloc == (alloc_func)0) { |
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183 | strm->zalloc = zcalloc; |
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184 | strm->opaque = (voidpf)0; |
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185 | } |
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186 | if (strm->zfree == (free_func)0) strm->zfree = zcfree; |
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187 | state = (struct inflate_state FAR *) |
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188 | ZALLOC(strm, 1, sizeof(struct inflate_state)); |
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189 | if (state == Z_NULL) return Z_MEM_ERROR; |
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190 | Tracev((stderr, "inflate: allocated\n")); |
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191 | strm->state = (struct internal_state FAR *)state; |
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192 | state->window = Z_NULL; |
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193 | ret = inflateReset2(strm, windowBits); |
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194 | if (ret != Z_OK) { |
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195 | ZFREE(strm, state); |
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196 | strm->state = Z_NULL; |
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197 | } |
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198 | return ret; |
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199 | } |
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200 | |
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201 | int ZEXPORT inflateInit_(strm, version, stream_size) |
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202 | z_streamp strm; |
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203 | const char *version; |
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204 | int stream_size; |
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205 | { |
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206 | return inflateInit2_(strm, DEF_WBITS, version, stream_size); |
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207 | } |
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208 | |
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209 | int ZEXPORT inflatePrime(strm, bits, value) |
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210 | z_streamp strm; |
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211 | int bits; |
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212 | int value; |
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213 | { |
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214 | struct inflate_state FAR *state; |
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215 | |
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216 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
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217 | state = (struct inflate_state FAR *)strm->state; |
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218 | if (bits < 0) { |
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219 | state->hold = 0; |
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220 | state->bits = 0; |
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221 | return Z_OK; |
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222 | } |
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223 | if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR; |
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224 | value &= (1L << bits) - 1; |
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225 | state->hold += value << state->bits; |
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226 | state->bits += bits; |
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227 | return Z_OK; |
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228 | } |
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229 | |
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230 | /* |
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231 | Return state with length and distance decoding tables and index sizes set to |
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232 | fixed code decoding. Normally this returns fixed tables from inffixed.h. |
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233 | If BUILDFIXED is defined, then instead this routine builds the tables the |
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234 | first time it's called, and returns those tables the first time and |
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235 | thereafter. This reduces the size of the code by about 2K bytes, in |
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236 | exchange for a little execution time. However, BUILDFIXED should not be |
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237 | used for threaded applications, since the rewriting of the tables and virgin |
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238 | may not be thread-safe. |
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239 | */ |
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240 | local void fixedtables(state) |
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241 | struct inflate_state FAR *state; |
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242 | { |
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243 | #ifdef BUILDFIXED |
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244 | static int virgin = 1; |
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245 | static code *lenfix, *distfix; |
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246 | static code fixed[544]; |
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247 | |
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248 | /* build fixed huffman tables if first call (may not be thread safe) */ |
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249 | if (virgin) { |
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250 | unsigned sym, bits; |
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251 | static code *next; |
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252 | |
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253 | /* literal/length table */ |
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254 | sym = 0; |
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255 | while (sym < 144) state->lens[sym++] = 8; |
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256 | while (sym < 256) state->lens[sym++] = 9; |
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257 | while (sym < 280) state->lens[sym++] = 7; |
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258 | while (sym < 288) state->lens[sym++] = 8; |
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259 | next = fixed; |
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260 | lenfix = next; |
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261 | bits = 9; |
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262 | inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); |
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263 | |
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264 | /* distance table */ |
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265 | sym = 0; |
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266 | while (sym < 32) state->lens[sym++] = 5; |
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267 | distfix = next; |
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268 | bits = 5; |
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269 | inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); |
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270 | |
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271 | /* do this just once */ |
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272 | virgin = 0; |
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273 | } |
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274 | #else /* !BUILDFIXED */ |
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275 | # include "inffixed.h" |
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276 | #endif /* BUILDFIXED */ |
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277 | state->lencode = lenfix; |
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278 | state->lenbits = 9; |
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279 | state->distcode = distfix; |
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280 | state->distbits = 5; |
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281 | } |
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282 | |
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283 | #ifdef MAKEFIXED |
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284 | #include <stdio.h> |
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285 | |
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286 | /* |
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287 | Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also |
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288 | defines BUILDFIXED, so the tables are built on the fly. makefixed() writes |
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289 | those tables to stdout, which would be piped to inffixed.h. A small program |
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290 | can simply call makefixed to do this: |
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291 | |
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292 | void makefixed(void); |
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293 | |
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294 | int main(void) |
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295 | { |
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296 | makefixed(); |
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297 | return 0; |
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298 | } |
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299 | |
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300 | Then that can be linked with zlib built with MAKEFIXED defined and run: |
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301 | |
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302 | a.out > inffixed.h |
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303 | */ |
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304 | void makefixed() |
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305 | { |
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306 | unsigned low, size; |
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307 | struct inflate_state state; |
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308 | |
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309 | fixedtables(&state); |
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310 | puts(" /* inffixed.h -- table for decoding fixed codes"); |
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311 | puts(" * Generated automatically by makefixed()."); |
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312 | puts(" */"); |
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313 | puts(""); |
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314 | puts(" /* WARNING: this file should *not* be used by applications."); |
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315 | puts(" It is part of the implementation of this library and is"); |
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316 | puts(" subject to change. Applications should only use zlib.h."); |
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317 | puts(" */"); |
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318 | puts(""); |
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319 | size = 1U << 9; |
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320 | printf(" static const code lenfix[%u] = {", size); |
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321 | low = 0; |
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322 | for (;;) { |
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323 | if ((low % 7) == 0) printf("\n "); |
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324 | printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits, |
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325 | state.lencode[low].val); |
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326 | if (++low == size) break; |
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327 | putchar(','); |
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328 | } |
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329 | puts("\n };"); |
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330 | size = 1U << 5; |
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331 | printf("\n static const code distfix[%u] = {", size); |
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332 | low = 0; |
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333 | for (;;) { |
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334 | if ((low % 6) == 0) printf("\n "); |
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335 | printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits, |
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336 | state.distcode[low].val); |
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337 | if (++low == size) break; |
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338 | putchar(','); |
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339 | } |
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340 | puts("\n };"); |
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341 | } |
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342 | #endif /* MAKEFIXED */ |
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343 | |
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344 | /* |
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345 | Update the window with the last wsize (normally 32K) bytes written before |
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346 | returning. If window does not exist yet, create it. This is only called |
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347 | when a window is already in use, or when output has been written during this |
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348 | inflate call, but the end of the deflate stream has not been reached yet. |
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349 | It is also called to create a window for dictionary data when a dictionary |
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350 | is loaded. |
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351 | |
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352 | Providing output buffers larger than 32K to inflate() should provide a speed |
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353 | advantage, since only the last 32K of output is copied to the sliding window |
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354 | upon return from inflate(), and since all distances after the first 32K of |
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355 | output will fall in the output data, making match copies simpler and faster. |
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356 | The advantage may be dependent on the size of the processor's data caches. |
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357 | */ |
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358 | local int updatewindow(strm, out) |
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359 | z_streamp strm; |
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360 | unsigned out; |
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361 | { |
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362 | struct inflate_state FAR *state; |
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363 | unsigned copy, dist; |
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364 | |
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365 | state = (struct inflate_state FAR *)strm->state; |
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366 | |
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367 | /* if it hasn't been done already, allocate space for the window */ |
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368 | if (state->window == Z_NULL) { |
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369 | state->window = (unsigned char FAR *) |
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370 | ZALLOC(strm, 1U << state->wbits, |
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371 | sizeof(unsigned char)); |
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372 | if (state->window == Z_NULL) return 1; |
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373 | } |
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374 | |
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375 | /* if window not in use yet, initialize */ |
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376 | if (state->wsize == 0) { |
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377 | state->wsize = 1U << state->wbits; |
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378 | state->wnext = 0; |
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379 | state->whave = 0; |
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380 | } |
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381 | |
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382 | /* copy state->wsize or less output bytes into the circular window */ |
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383 | copy = out - strm->avail_out; |
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384 | if (copy >= state->wsize) { |
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385 | zmemcpy(state->window, strm->next_out - state->wsize, state->wsize); |
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386 | state->wnext = 0; |
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387 | state->whave = state->wsize; |
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388 | } |
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389 | else { |
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390 | dist = state->wsize - state->wnext; |
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391 | if (dist > copy) dist = copy; |
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392 | zmemcpy(state->window + state->wnext, strm->next_out - copy, dist); |
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393 | copy -= dist; |
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394 | if (copy) { |
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395 | zmemcpy(state->window, strm->next_out - copy, copy); |
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396 | state->wnext = copy; |
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397 | state->whave = state->wsize; |
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398 | } |
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399 | else { |
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400 | state->wnext += dist; |
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401 | if (state->wnext == state->wsize) state->wnext = 0; |
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402 | if (state->whave < state->wsize) state->whave += dist; |
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403 | } |
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404 | } |
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405 | return 0; |
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406 | } |
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407 | |
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408 | /* Macros for inflate(): */ |
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409 | |
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410 | /* check function to use adler32() for zlib or crc32() for gzip */ |
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411 | #ifdef GUNZIP |
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412 | # define UPDATE(check, buf, len) \ |
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413 | (state->flags ? crc32(check, buf, len) : adler32(check, buf, len)) |
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414 | #else |
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415 | # define UPDATE(check, buf, len) adler32(check, buf, len) |
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416 | #endif |
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417 | |
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418 | /* check macros for header crc */ |
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419 | #ifdef GUNZIP |
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420 | # define CRC2(check, word) \ |
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421 | do { \ |
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422 | hbuf[0] = (unsigned char)(word); \ |
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423 | hbuf[1] = (unsigned char)((word) >> 8); \ |
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424 | check = crc32(check, hbuf, 2); \ |
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425 | } while (0) |
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426 | |
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427 | # define CRC4(check, word) \ |
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428 | do { \ |
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429 | hbuf[0] = (unsigned char)(word); \ |
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430 | hbuf[1] = (unsigned char)((word) >> 8); \ |
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431 | hbuf[2] = (unsigned char)((word) >> 16); \ |
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432 | hbuf[3] = (unsigned char)((word) >> 24); \ |
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433 | check = crc32(check, hbuf, 4); \ |
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434 | } while (0) |
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435 | #endif |
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436 | |
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437 | /* Load registers with state in inflate() for speed */ |
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438 | #define LOAD() \ |
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439 | do { \ |
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440 | put = strm->next_out; \ |
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441 | left = strm->avail_out; \ |
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442 | next = strm->next_in; \ |
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443 | have = strm->avail_in; \ |
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444 | hold = state->hold; \ |
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445 | bits = state->bits; \ |
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446 | } while (0) |
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447 | |
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448 | /* Restore state from registers in inflate() */ |
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449 | #define RESTORE() \ |
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450 | do { \ |
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451 | strm->next_out = put; \ |
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452 | strm->avail_out = left; \ |
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453 | strm->next_in = next; \ |
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454 | strm->avail_in = have; \ |
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455 | state->hold = hold; \ |
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456 | state->bits = bits; \ |
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457 | } while (0) |
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458 | |
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459 | /* Clear the input bit accumulator */ |
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460 | #define INITBITS() \ |
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461 | do { \ |
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462 | hold = 0; \ |
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463 | bits = 0; \ |
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464 | } while (0) |
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465 | |
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466 | /* Get a byte of input into the bit accumulator, or return from inflate() |
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467 | if there is no input available. */ |
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468 | #define PULLBYTE() \ |
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469 | do { \ |
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470 | if (have == 0) goto inf_leave; \ |
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471 | have--; \ |
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472 | hold += (unsigned long)(*next++) << bits; \ |
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473 | bits += 8; \ |
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474 | } while (0) |
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475 | |
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476 | /* Assure that there are at least n bits in the bit accumulator. If there is |
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477 | not enough available input to do that, then return from inflate(). */ |
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478 | #define NEEDBITS(n) \ |
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479 | do { \ |
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480 | while (bits < (unsigned)(n)) \ |
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481 | PULLBYTE(); \ |
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482 | } while (0) |
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483 | |
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484 | /* Return the low n bits of the bit accumulator (n < 16) */ |
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485 | #define BITS(n) \ |
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486 | ((unsigned)hold & ((1U << (n)) - 1)) |
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487 | |
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488 | /* Remove n bits from the bit accumulator */ |
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489 | #define DROPBITS(n) \ |
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490 | do { \ |
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491 | hold >>= (n); \ |
---|
492 | bits -= (unsigned)(n); \ |
---|
493 | } while (0) |
---|
494 | |
---|
495 | /* Remove zero to seven bits as needed to go to a byte boundary */ |
---|
496 | #define BYTEBITS() \ |
---|
497 | do { \ |
---|
498 | hold >>= bits & 7; \ |
---|
499 | bits -= bits & 7; \ |
---|
500 | } while (0) |
---|
501 | |
---|
502 | /* Reverse the bytes in a 32-bit value */ |
---|
503 | #define REVERSE(q) \ |
---|
504 | ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \ |
---|
505 | (((q) & 0xff00) << 8) + (((q) & 0xff) << 24)) |
---|
506 | |
---|
507 | /* |
---|
508 | inflate() uses a state machine to process as much input data and generate as |
---|
509 | much output data as possible before returning. The state machine is |
---|
510 | structured roughly as follows: |
---|
511 | |
---|
512 | for (;;) switch (state) { |
---|
513 | ... |
---|
514 | case STATEn: |
---|
515 | if (not enough input data or output space to make progress) |
---|
516 | return; |
---|
517 | ... make progress ... |
---|
518 | state = STATEm; |
---|
519 | break; |
---|
520 | ... |
---|
521 | } |
---|
522 | |
---|
523 | so when inflate() is called again, the same case is attempted again, and |
---|
524 | if the appropriate resources are provided, the machine proceeds to the |
---|
525 | next state. The NEEDBITS() macro is usually the way the state evaluates |
---|
526 | whether it can proceed or should return. NEEDBITS() does the return if |
---|
527 | the requested bits are not available. The typical use of the BITS macros |
---|
528 | is: |
---|
529 | |
---|
530 | NEEDBITS(n); |
---|
531 | ... do something with BITS(n) ... |
---|
532 | DROPBITS(n); |
---|
533 | |
---|
534 | where NEEDBITS(n) either returns from inflate() if there isn't enough |
---|
535 | input left to load n bits into the accumulator, or it continues. BITS(n) |
---|
536 | gives the low n bits in the accumulator. When done, DROPBITS(n) drops |
---|
537 | the low n bits off the accumulator. INITBITS() clears the accumulator |
---|
538 | and sets the number of available bits to zero. BYTEBITS() discards just |
---|
539 | enough bits to put the accumulator on a byte boundary. After BYTEBITS() |
---|
540 | and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. |
---|
541 | |
---|
542 | NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return |
---|
543 | if there is no input available. The decoding of variable length codes uses |
---|
544 | PULLBYTE() directly in order to pull just enough bytes to decode the next |
---|
545 | code, and no more. |
---|
546 | |
---|
547 | Some states loop until they get enough input, making sure that enough |
---|
548 | state information is maintained to continue the loop where it left off |
---|
549 | if NEEDBITS() returns in the loop. For example, want, need, and keep |
---|
550 | would all have to actually be part of the saved state in case NEEDBITS() |
---|
551 | returns: |
---|
552 | |
---|
553 | case STATEw: |
---|
554 | while (want < need) { |
---|
555 | NEEDBITS(n); |
---|
556 | keep[want++] = BITS(n); |
---|
557 | DROPBITS(n); |
---|
558 | } |
---|
559 | state = STATEx; |
---|
560 | case STATEx: |
---|
561 | |
---|
562 | As shown above, if the next state is also the next case, then the break |
---|
563 | is omitted. |
---|
564 | |
---|
565 | A state may also return if there is not enough output space available to |
---|
566 | complete that state. Those states are copying stored data, writing a |
---|
567 | literal byte, and copying a matching string. |
---|
568 | |
---|
569 | When returning, a "goto inf_leave" is used to update the total counters, |
---|
570 | update the check value, and determine whether any progress has been made |
---|
571 | during that inflate() call in order to return the proper return code. |
---|
572 | Progress is defined as a change in either strm->avail_in or strm->avail_out. |
---|
573 | When there is a window, goto inf_leave will update the window with the last |
---|
574 | output written. If a goto inf_leave occurs in the middle of decompression |
---|
575 | and there is no window currently, goto inf_leave will create one and copy |
---|
576 | output to the window for the next call of inflate(). |
---|
577 | |
---|
578 | In this implementation, the flush parameter of inflate() only affects the |
---|
579 | return code (per zlib.h). inflate() always writes as much as possible to |
---|
580 | strm->next_out, given the space available and the provided input--the effect |
---|
581 | documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers |
---|
582 | the allocation of and copying into a sliding window until necessary, which |
---|
583 | provides the effect documented in zlib.h for Z_FINISH when the entire input |
---|
584 | stream available. So the only thing the flush parameter actually does is: |
---|
585 | when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it |
---|
586 | will return Z_BUF_ERROR if it has not reached the end of the stream. |
---|
587 | */ |
---|
588 | |
---|
589 | int ZEXPORT inflate(strm, flush) |
---|
590 | z_streamp strm; |
---|
591 | int flush; |
---|
592 | { |
---|
593 | struct inflate_state FAR *state; |
---|
594 | unsigned char FAR *next; /* next input */ |
---|
595 | unsigned char FAR *put; /* next output */ |
---|
596 | unsigned have, left; /* available input and output */ |
---|
597 | unsigned long hold; /* bit buffer */ |
---|
598 | unsigned bits; /* bits in bit buffer */ |
---|
599 | unsigned in, out; /* save starting available input and output */ |
---|
600 | unsigned copy; /* number of stored or match bytes to copy */ |
---|
601 | unsigned char FAR *from; /* where to copy match bytes from */ |
---|
602 | code here; /* current decoding table entry */ |
---|
603 | code last; /* parent table entry */ |
---|
604 | unsigned len; /* length to copy for repeats, bits to drop */ |
---|
605 | int ret; /* return code */ |
---|
606 | #ifdef GUNZIP |
---|
607 | unsigned char hbuf[4]; /* buffer for gzip header crc calculation */ |
---|
608 | #endif |
---|
609 | static const unsigned short order[19] = /* permutation of code lengths */ |
---|
610 | {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
---|
611 | |
---|
612 | if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL || |
---|
613 | (strm->next_in == Z_NULL && strm->avail_in != 0)) |
---|
614 | return Z_STREAM_ERROR; |
---|
615 | |
---|
616 | state = (struct inflate_state FAR *)strm->state; |
---|
617 | if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ |
---|
618 | LOAD(); |
---|
619 | in = have; |
---|
620 | out = left; |
---|
621 | ret = Z_OK; |
---|
622 | for (;;) |
---|
623 | switch (state->mode) { |
---|
624 | case HEAD: |
---|
625 | if (state->wrap == 0) { |
---|
626 | state->mode = TYPEDO; |
---|
627 | break; |
---|
628 | } |
---|
629 | NEEDBITS(16); |
---|
630 | #ifdef GUNZIP |
---|
631 | if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */ |
---|
632 | state->check = crc32(0L, Z_NULL, 0); |
---|
633 | CRC2(state->check, hold); |
---|
634 | INITBITS(); |
---|
635 | state->mode = FLAGS; |
---|
636 | break; |
---|
637 | } |
---|
638 | state->flags = 0; /* expect zlib header */ |
---|
639 | if (state->head != Z_NULL) |
---|
640 | state->head->done = -1; |
---|
641 | if (!(state->wrap & 1) || /* check if zlib header allowed */ |
---|
642 | #else |
---|
643 | if ( |
---|
644 | #endif |
---|
645 | ((BITS(8) << 8) + (hold >> 8)) % 31) { |
---|
646 | strm->msg = (char *)"incorrect header check"; |
---|
647 | state->mode = BAD; |
---|
648 | break; |
---|
649 | } |
---|
650 | if (BITS(4) != Z_DEFLATED) { |
---|
651 | strm->msg = (char *)"unknown compression method"; |
---|
652 | state->mode = BAD; |
---|
653 | break; |
---|
654 | } |
---|
655 | DROPBITS(4); |
---|
656 | len = BITS(4) + 8; |
---|
657 | if (state->wbits == 0) |
---|
658 | state->wbits = len; |
---|
659 | else if (len > state->wbits) { |
---|
660 | strm->msg = (char *)"invalid window size"; |
---|
661 | state->mode = BAD; |
---|
662 | break; |
---|
663 | } |
---|
664 | state->dmax = 1U << len; |
---|
665 | Tracev((stderr, "inflate: zlib header ok\n")); |
---|
666 | strm->adler = state->check = adler32(0L, Z_NULL, 0); |
---|
667 | state->mode = hold & 0x200 ? DICTID : TYPE; |
---|
668 | INITBITS(); |
---|
669 | break; |
---|
670 | #ifdef GUNZIP |
---|
671 | case FLAGS: |
---|
672 | NEEDBITS(16); |
---|
673 | state->flags = (int)(hold); |
---|
674 | if ((state->flags & 0xff) != Z_DEFLATED) { |
---|
675 | strm->msg = (char *)"unknown compression method"; |
---|
676 | state->mode = BAD; |
---|
677 | break; |
---|
678 | } |
---|
679 | if (state->flags & 0xe000) { |
---|
680 | strm->msg = (char *)"unknown header flags set"; |
---|
681 | state->mode = BAD; |
---|
682 | break; |
---|
683 | } |
---|
684 | if (state->head != Z_NULL) |
---|
685 | state->head->text = (int)((hold >> 8) & 1); |
---|
686 | if (state->flags & 0x0200) CRC2(state->check, hold); |
---|
687 | INITBITS(); |
---|
688 | state->mode = TIME; |
---|
689 | case TIME: |
---|
690 | NEEDBITS(32); |
---|
691 | if (state->head != Z_NULL) |
---|
692 | state->head->time = hold; |
---|
693 | if (state->flags & 0x0200) CRC4(state->check, hold); |
---|
694 | INITBITS(); |
---|
695 | state->mode = OS; |
---|
696 | case OS: |
---|
697 | NEEDBITS(16); |
---|
698 | if (state->head != Z_NULL) { |
---|
699 | state->head->xflags = (int)(hold & 0xff); |
---|
700 | state->head->os = (int)(hold >> 8); |
---|
701 | } |
---|
702 | if (state->flags & 0x0200) CRC2(state->check, hold); |
---|
703 | INITBITS(); |
---|
704 | state->mode = EXLEN; |
---|
705 | case EXLEN: |
---|
706 | if (state->flags & 0x0400) { |
---|
707 | NEEDBITS(16); |
---|
708 | state->length = (unsigned)(hold); |
---|
709 | if (state->head != Z_NULL) |
---|
710 | state->head->extra_len = (unsigned)hold; |
---|
711 | if (state->flags & 0x0200) CRC2(state->check, hold); |
---|
712 | INITBITS(); |
---|
713 | } |
---|
714 | else if (state->head != Z_NULL) |
---|
715 | state->head->extra = Z_NULL; |
---|
716 | state->mode = EXTRA; |
---|
717 | case EXTRA: |
---|
718 | if (state->flags & 0x0400) { |
---|
719 | copy = state->length; |
---|
720 | if (copy > have) copy = have; |
---|
721 | if (copy) { |
---|
722 | if (state->head != Z_NULL && |
---|
723 | state->head->extra != Z_NULL) { |
---|
724 | len = state->head->extra_len - state->length; |
---|
725 | zmemcpy(state->head->extra + len, next, |
---|
726 | len + copy > state->head->extra_max ? |
---|
727 | state->head->extra_max - len : copy); |
---|
728 | } |
---|
729 | if (state->flags & 0x0200) |
---|
730 | state->check = crc32(state->check, next, copy); |
---|
731 | have -= copy; |
---|
732 | next += copy; |
---|
733 | state->length -= copy; |
---|
734 | } |
---|
735 | if (state->length) goto inf_leave; |
---|
736 | } |
---|
737 | state->length = 0; |
---|
738 | state->mode = NAME; |
---|
739 | case NAME: |
---|
740 | if (state->flags & 0x0800) { |
---|
741 | if (have == 0) goto inf_leave; |
---|
742 | copy = 0; |
---|
743 | do { |
---|
744 | len = (unsigned)(next[copy++]); |
---|
745 | if (state->head != Z_NULL && |
---|
746 | state->head->name != Z_NULL && |
---|
747 | state->length < state->head->name_max) |
---|
748 | state->head->name[state->length++] = len; |
---|
749 | } while (len && copy < have); |
---|
750 | if (state->flags & 0x0200) |
---|
751 | state->check = crc32(state->check, next, copy); |
---|
752 | have -= copy; |
---|
753 | next += copy; |
---|
754 | if (len) goto inf_leave; |
---|
755 | } |
---|
756 | else if (state->head != Z_NULL) |
---|
757 | state->head->name = Z_NULL; |
---|
758 | state->length = 0; |
---|
759 | state->mode = COMMENT; |
---|
760 | case COMMENT: |
---|
761 | if (state->flags & 0x1000) { |
---|
762 | if (have == 0) goto inf_leave; |
---|
763 | copy = 0; |
---|
764 | do { |
---|
765 | len = (unsigned)(next[copy++]); |
---|
766 | if (state->head != Z_NULL && |
---|
767 | state->head->comment != Z_NULL && |
---|
768 | state->length < state->head->comm_max) |
---|
769 | state->head->comment[state->length++] = len; |
---|
770 | } while (len && copy < have); |
---|
771 | if (state->flags & 0x0200) |
---|
772 | state->check = crc32(state->check, next, copy); |
---|
773 | have -= copy; |
---|
774 | next += copy; |
---|
775 | if (len) goto inf_leave; |
---|
776 | } |
---|
777 | else if (state->head != Z_NULL) |
---|
778 | state->head->comment = Z_NULL; |
---|
779 | state->mode = HCRC; |
---|
780 | case HCRC: |
---|
781 | if (state->flags & 0x0200) { |
---|
782 | NEEDBITS(16); |
---|
783 | if (hold != (state->check & 0xffff)) { |
---|
784 | strm->msg = (char *)"header crc mismatch"; |
---|
785 | state->mode = BAD; |
---|
786 | break; |
---|
787 | } |
---|
788 | INITBITS(); |
---|
789 | } |
---|
790 | if (state->head != Z_NULL) { |
---|
791 | state->head->hcrc = (int)((state->flags >> 9) & 1); |
---|
792 | state->head->done = 1; |
---|
793 | } |
---|
794 | strm->adler = state->check = crc32(0L, Z_NULL, 0); |
---|
795 | state->mode = TYPE; |
---|
796 | break; |
---|
797 | #endif |
---|
798 | case DICTID: |
---|
799 | NEEDBITS(32); |
---|
800 | strm->adler = state->check = REVERSE(hold); |
---|
801 | INITBITS(); |
---|
802 | state->mode = DICT; |
---|
803 | case DICT: |
---|
804 | if (state->havedict == 0) { |
---|
805 | RESTORE(); |
---|
806 | return Z_NEED_DICT; |
---|
807 | } |
---|
808 | strm->adler = state->check = adler32(0L, Z_NULL, 0); |
---|
809 | state->mode = TYPE; |
---|
810 | case TYPE: |
---|
811 | if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave; |
---|
812 | case TYPEDO: |
---|
813 | if (state->last) { |
---|
814 | BYTEBITS(); |
---|
815 | state->mode = CHECK; |
---|
816 | break; |
---|
817 | } |
---|
818 | NEEDBITS(3); |
---|
819 | state->last = BITS(1); |
---|
820 | DROPBITS(1); |
---|
821 | switch (BITS(2)) { |
---|
822 | case 0: /* stored block */ |
---|
823 | Tracev((stderr, "inflate: stored block%s\n", |
---|
824 | state->last ? " (last)" : "")); |
---|
825 | state->mode = STORED; |
---|
826 | break; |
---|
827 | case 1: /* fixed block */ |
---|
828 | fixedtables(state); |
---|
829 | Tracev((stderr, "inflate: fixed codes block%s\n", |
---|
830 | state->last ? " (last)" : "")); |
---|
831 | state->mode = LEN_; /* decode codes */ |
---|
832 | if (flush == Z_TREES) { |
---|
833 | DROPBITS(2); |
---|
834 | goto inf_leave; |
---|
835 | } |
---|
836 | break; |
---|
837 | case 2: /* dynamic block */ |
---|
838 | Tracev((stderr, "inflate: dynamic codes block%s\n", |
---|
839 | state->last ? " (last)" : "")); |
---|
840 | state->mode = TABLE; |
---|
841 | break; |
---|
842 | case 3: |
---|
843 | strm->msg = (char *)"invalid block type"; |
---|
844 | state->mode = BAD; |
---|
845 | } |
---|
846 | DROPBITS(2); |
---|
847 | break; |
---|
848 | case STORED: |
---|
849 | BYTEBITS(); /* go to byte boundary */ |
---|
850 | NEEDBITS(32); |
---|
851 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
---|
852 | strm->msg = (char *)"invalid stored block lengths"; |
---|
853 | state->mode = BAD; |
---|
854 | break; |
---|
855 | } |
---|
856 | state->length = (unsigned)hold & 0xffff; |
---|
857 | Tracev((stderr, "inflate: stored length %u\n", |
---|
858 | state->length)); |
---|
859 | INITBITS(); |
---|
860 | state->mode = COPY_; |
---|
861 | if (flush == Z_TREES) goto inf_leave; |
---|
862 | case COPY_: |
---|
863 | state->mode = COPY; |
---|
864 | case COPY: |
---|
865 | copy = state->length; |
---|
866 | if (copy) { |
---|
867 | if (copy > have) copy = have; |
---|
868 | if (copy > left) copy = left; |
---|
869 | if (copy == 0) goto inf_leave; |
---|
870 | zmemcpy(put, next, copy); |
---|
871 | have -= copy; |
---|
872 | next += copy; |
---|
873 | left -= copy; |
---|
874 | put += copy; |
---|
875 | state->length -= copy; |
---|
876 | break; |
---|
877 | } |
---|
878 | Tracev((stderr, "inflate: stored end\n")); |
---|
879 | state->mode = TYPE; |
---|
880 | break; |
---|
881 | case TABLE: |
---|
882 | NEEDBITS(14); |
---|
883 | state->nlen = BITS(5) + 257; |
---|
884 | DROPBITS(5); |
---|
885 | state->ndist = BITS(5) + 1; |
---|
886 | DROPBITS(5); |
---|
887 | state->ncode = BITS(4) + 4; |
---|
888 | DROPBITS(4); |
---|
889 | #ifndef PKZIP_BUG_WORKAROUND |
---|
890 | if (state->nlen > 286 || state->ndist > 30) { |
---|
891 | strm->msg = (char *)"too many length or distance symbols"; |
---|
892 | state->mode = BAD; |
---|
893 | break; |
---|
894 | } |
---|
895 | #endif |
---|
896 | Tracev((stderr, "inflate: table sizes ok\n")); |
---|
897 | state->have = 0; |
---|
898 | state->mode = LENLENS; |
---|
899 | case LENLENS: |
---|
900 | while (state->have < state->ncode) { |
---|
901 | NEEDBITS(3); |
---|
902 | state->lens[order[state->have++]] = (unsigned short)BITS(3); |
---|
903 | DROPBITS(3); |
---|
904 | } |
---|
905 | while (state->have < 19) |
---|
906 | state->lens[order[state->have++]] = 0; |
---|
907 | state->next = state->codes; |
---|
908 | state->lencode = (code const FAR *)(state->next); |
---|
909 | state->lenbits = 7; |
---|
910 | ret = inflate_table(CODES, state->lens, 19, &(state->next), |
---|
911 | &(state->lenbits), state->work); |
---|
912 | if (ret) { |
---|
913 | strm->msg = (char *)"invalid code lengths set"; |
---|
914 | state->mode = BAD; |
---|
915 | break; |
---|
916 | } |
---|
917 | Tracev((stderr, "inflate: code lengths ok\n")); |
---|
918 | state->have = 0; |
---|
919 | state->mode = CODELENS; |
---|
920 | case CODELENS: |
---|
921 | while (state->have < state->nlen + state->ndist) { |
---|
922 | for (;;) { |
---|
923 | here = state->lencode[BITS(state->lenbits)]; |
---|
924 | if ((unsigned)(here.bits) <= bits) break; |
---|
925 | PULLBYTE(); |
---|
926 | } |
---|
927 | if (here.val < 16) { |
---|
928 | NEEDBITS(here.bits); |
---|
929 | DROPBITS(here.bits); |
---|
930 | state->lens[state->have++] = here.val; |
---|
931 | } |
---|
932 | else { |
---|
933 | if (here.val == 16) { |
---|
934 | NEEDBITS(here.bits + 2); |
---|
935 | DROPBITS(here.bits); |
---|
936 | if (state->have == 0) { |
---|
937 | strm->msg = (char *)"invalid bit length repeat"; |
---|
938 | state->mode = BAD; |
---|
939 | break; |
---|
940 | } |
---|
941 | len = state->lens[state->have - 1]; |
---|
942 | copy = 3 + BITS(2); |
---|
943 | DROPBITS(2); |
---|
944 | } |
---|
945 | else if (here.val == 17) { |
---|
946 | NEEDBITS(here.bits + 3); |
---|
947 | DROPBITS(here.bits); |
---|
948 | len = 0; |
---|
949 | copy = 3 + BITS(3); |
---|
950 | DROPBITS(3); |
---|
951 | } |
---|
952 | else { |
---|
953 | NEEDBITS(here.bits + 7); |
---|
954 | DROPBITS(here.bits); |
---|
955 | len = 0; |
---|
956 | copy = 11 + BITS(7); |
---|
957 | DROPBITS(7); |
---|
958 | } |
---|
959 | if (state->have + copy > state->nlen + state->ndist) { |
---|
960 | strm->msg = (char *)"invalid bit length repeat"; |
---|
961 | state->mode = BAD; |
---|
962 | break; |
---|
963 | } |
---|
964 | while (copy--) |
---|
965 | state->lens[state->have++] = (unsigned short)len; |
---|
966 | } |
---|
967 | } |
---|
968 | |
---|
969 | /* handle error breaks in while */ |
---|
970 | if (state->mode == BAD) break; |
---|
971 | |
---|
972 | /* check for end-of-block code (better have one) */ |
---|
973 | if (state->lens[256] == 0) { |
---|
974 | strm->msg = (char *)"invalid code -- missing end-of-block"; |
---|
975 | state->mode = BAD; |
---|
976 | break; |
---|
977 | } |
---|
978 | |
---|
979 | /* build code tables -- note: do not change the lenbits or distbits |
---|
980 | values here (9 and 6) without reading the comments in inftrees.h |
---|
981 | concerning the ENOUGH constants, which depend on those values */ |
---|
982 | state->next = state->codes; |
---|
983 | state->lencode = (code const FAR *)(state->next); |
---|
984 | state->lenbits = 9; |
---|
985 | ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), |
---|
986 | &(state->lenbits), state->work); |
---|
987 | if (ret) { |
---|
988 | strm->msg = (char *)"invalid literal/lengths set"; |
---|
989 | state->mode = BAD; |
---|
990 | break; |
---|
991 | } |
---|
992 | state->distcode = (code const FAR *)(state->next); |
---|
993 | state->distbits = 6; |
---|
994 | ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
---|
995 | &(state->next), &(state->distbits), state->work); |
---|
996 | if (ret) { |
---|
997 | strm->msg = (char *)"invalid distances set"; |
---|
998 | state->mode = BAD; |
---|
999 | break; |
---|
1000 | } |
---|
1001 | Tracev((stderr, "inflate: codes ok\n")); |
---|
1002 | state->mode = LEN_; |
---|
1003 | if (flush == Z_TREES) goto inf_leave; |
---|
1004 | case LEN_: |
---|
1005 | state->mode = LEN; |
---|
1006 | case LEN: |
---|
1007 | if (have >= 6 && left >= 258) { |
---|
1008 | RESTORE(); |
---|
1009 | inflate_fast(strm, out); |
---|
1010 | LOAD(); |
---|
1011 | if (state->mode == TYPE) |
---|
1012 | state->back = -1; |
---|
1013 | break; |
---|
1014 | } |
---|
1015 | state->back = 0; |
---|
1016 | for (;;) { |
---|
1017 | here = state->lencode[BITS(state->lenbits)]; |
---|
1018 | if ((unsigned)(here.bits) <= bits) break; |
---|
1019 | PULLBYTE(); |
---|
1020 | } |
---|
1021 | if (here.op && (here.op & 0xf0) == 0) { |
---|
1022 | last = here; |
---|
1023 | for (;;) { |
---|
1024 | here = state->lencode[last.val + |
---|
1025 | (BITS(last.bits + last.op) >> last.bits)]; |
---|
1026 | if ((unsigned)(last.bits + here.bits) <= bits) break; |
---|
1027 | PULLBYTE(); |
---|
1028 | } |
---|
1029 | DROPBITS(last.bits); |
---|
1030 | state->back += last.bits; |
---|
1031 | } |
---|
1032 | DROPBITS(here.bits); |
---|
1033 | state->back += here.bits; |
---|
1034 | state->length = (unsigned)here.val; |
---|
1035 | if ((int)(here.op) == 0) { |
---|
1036 | Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? |
---|
1037 | "inflate: literal '%c'\n" : |
---|
1038 | "inflate: literal 0x%02x\n", here.val)); |
---|
1039 | state->mode = LIT; |
---|
1040 | break; |
---|
1041 | } |
---|
1042 | if (here.op & 32) { |
---|
1043 | Tracevv((stderr, "inflate: end of block\n")); |
---|
1044 | state->back = -1; |
---|
1045 | state->mode = TYPE; |
---|
1046 | break; |
---|
1047 | } |
---|
1048 | if (here.op & 64) { |
---|
1049 | strm->msg = (char *)"invalid literal/length code"; |
---|
1050 | state->mode = BAD; |
---|
1051 | break; |
---|
1052 | } |
---|
1053 | state->extra = (unsigned)(here.op) & 15; |
---|
1054 | state->mode = LENEXT; |
---|
1055 | case LENEXT: |
---|
1056 | if (state->extra) { |
---|
1057 | NEEDBITS(state->extra); |
---|
1058 | state->length += BITS(state->extra); |
---|
1059 | DROPBITS(state->extra); |
---|
1060 | state->back += state->extra; |
---|
1061 | } |
---|
1062 | Tracevv((stderr, "inflate: length %u\n", state->length)); |
---|
1063 | state->was = state->length; |
---|
1064 | state->mode = DIST; |
---|
1065 | case DIST: |
---|
1066 | for (;;) { |
---|
1067 | here = state->distcode[BITS(state->distbits)]; |
---|
1068 | if ((unsigned)(here.bits) <= bits) break; |
---|
1069 | PULLBYTE(); |
---|
1070 | } |
---|
1071 | if ((here.op & 0xf0) == 0) { |
---|
1072 | last = here; |
---|
1073 | for (;;) { |
---|
1074 | here = state->distcode[last.val + |
---|
1075 | (BITS(last.bits + last.op) >> last.bits)]; |
---|
1076 | if ((unsigned)(last.bits + here.bits) <= bits) break; |
---|
1077 | PULLBYTE(); |
---|
1078 | } |
---|
1079 | DROPBITS(last.bits); |
---|
1080 | state->back += last.bits; |
---|
1081 | } |
---|
1082 | DROPBITS(here.bits); |
---|
1083 | state->back += here.bits; |
---|
1084 | if (here.op & 64) { |
---|
1085 | strm->msg = (char *)"invalid distance code"; |
---|
1086 | state->mode = BAD; |
---|
1087 | break; |
---|
1088 | } |
---|
1089 | state->offset = (unsigned)here.val; |
---|
1090 | state->extra = (unsigned)(here.op) & 15; |
---|
1091 | state->mode = DISTEXT; |
---|
1092 | case DISTEXT: |
---|
1093 | if (state->extra) { |
---|
1094 | NEEDBITS(state->extra); |
---|
1095 | state->offset += BITS(state->extra); |
---|
1096 | DROPBITS(state->extra); |
---|
1097 | state->back += state->extra; |
---|
1098 | } |
---|
1099 | #ifdef INFLATE_STRICT |
---|
1100 | if (state->offset > state->dmax) { |
---|
1101 | strm->msg = (char *)"invalid distance too far back"; |
---|
1102 | state->mode = BAD; |
---|
1103 | break; |
---|
1104 | } |
---|
1105 | #endif |
---|
1106 | Tracevv((stderr, "inflate: distance %u\n", state->offset)); |
---|
1107 | state->mode = MATCH; |
---|
1108 | case MATCH: |
---|
1109 | if (left == 0) goto inf_leave; |
---|
1110 | copy = out - left; |
---|
1111 | if (state->offset > copy) { /* copy from window */ |
---|
1112 | copy = state->offset - copy; |
---|
1113 | if (copy > state->whave) { |
---|
1114 | if (state->sane) { |
---|
1115 | strm->msg = (char *)"invalid distance too far back"; |
---|
1116 | state->mode = BAD; |
---|
1117 | break; |
---|
1118 | } |
---|
1119 | #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR |
---|
1120 | Trace((stderr, "inflate.c too far\n")); |
---|
1121 | copy -= state->whave; |
---|
1122 | if (copy > state->length) copy = state->length; |
---|
1123 | if (copy > left) copy = left; |
---|
1124 | left -= copy; |
---|
1125 | state->length -= copy; |
---|
1126 | do { |
---|
1127 | *put++ = 0; |
---|
1128 | } while (--copy); |
---|
1129 | if (state->length == 0) state->mode = LEN; |
---|
1130 | break; |
---|
1131 | #endif |
---|
1132 | } |
---|
1133 | if (copy > state->wnext) { |
---|
1134 | copy -= state->wnext; |
---|
1135 | from = state->window + (state->wsize - copy); |
---|
1136 | } |
---|
1137 | else |
---|
1138 | from = state->window + (state->wnext - copy); |
---|
1139 | if (copy > state->length) copy = state->length; |
---|
1140 | } |
---|
1141 | else { /* copy from output */ |
---|
1142 | from = put - state->offset; |
---|
1143 | copy = state->length; |
---|
1144 | } |
---|
1145 | if (copy > left) copy = left; |
---|
1146 | left -= copy; |
---|
1147 | state->length -= copy; |
---|
1148 | do { |
---|
1149 | *put++ = *from++; |
---|
1150 | } while (--copy); |
---|
1151 | if (state->length == 0) state->mode = LEN; |
---|
1152 | break; |
---|
1153 | case LIT: |
---|
1154 | if (left == 0) goto inf_leave; |
---|
1155 | *put++ = (unsigned char)(state->length); |
---|
1156 | left--; |
---|
1157 | state->mode = LEN; |
---|
1158 | break; |
---|
1159 | case CHECK: |
---|
1160 | if (state->wrap) { |
---|
1161 | NEEDBITS(32); |
---|
1162 | out -= left; |
---|
1163 | strm->total_out += out; |
---|
1164 | state->total += out; |
---|
1165 | if (out) |
---|
1166 | strm->adler = state->check = |
---|
1167 | UPDATE(state->check, put - out, out); |
---|
1168 | out = left; |
---|
1169 | if (( |
---|
1170 | #ifdef GUNZIP |
---|
1171 | state->flags ? hold : |
---|
1172 | #endif |
---|
1173 | REVERSE(hold)) != state->check) { |
---|
1174 | strm->msg = (char *)"incorrect data check"; |
---|
1175 | state->mode = BAD; |
---|
1176 | break; |
---|
1177 | } |
---|
1178 | INITBITS(); |
---|
1179 | Tracev((stderr, "inflate: check matches trailer\n")); |
---|
1180 | } |
---|
1181 | #ifdef GUNZIP |
---|
1182 | state->mode = LENGTH; |
---|
1183 | case LENGTH: |
---|
1184 | if (state->wrap && state->flags) { |
---|
1185 | NEEDBITS(32); |
---|
1186 | if (hold != (state->total & 0xffffffffUL)) { |
---|
1187 | strm->msg = (char *)"incorrect length check"; |
---|
1188 | state->mode = BAD; |
---|
1189 | break; |
---|
1190 | } |
---|
1191 | INITBITS(); |
---|
1192 | Tracev((stderr, "inflate: length matches trailer\n")); |
---|
1193 | } |
---|
1194 | #endif |
---|
1195 | state->mode = DONE; |
---|
1196 | case DONE: |
---|
1197 | ret = Z_STREAM_END; |
---|
1198 | goto inf_leave; |
---|
1199 | case BAD: |
---|
1200 | ret = Z_DATA_ERROR; |
---|
1201 | goto inf_leave; |
---|
1202 | case MEM: |
---|
1203 | return Z_MEM_ERROR; |
---|
1204 | case SYNC: |
---|
1205 | default: |
---|
1206 | return Z_STREAM_ERROR; |
---|
1207 | } |
---|
1208 | |
---|
1209 | /* |
---|
1210 | Return from inflate(), updating the total counts and the check value. |
---|
1211 | If there was no progress during the inflate() call, return a buffer |
---|
1212 | error. Call updatewindow() to create and/or update the window state. |
---|
1213 | Note: a memory error from inflate() is non-recoverable. |
---|
1214 | */ |
---|
1215 | inf_leave: |
---|
1216 | RESTORE(); |
---|
1217 | if (state->wsize || (state->mode < CHECK && out != strm->avail_out)) |
---|
1218 | if (updatewindow(strm, out)) { |
---|
1219 | state->mode = MEM; |
---|
1220 | return Z_MEM_ERROR; |
---|
1221 | } |
---|
1222 | in -= strm->avail_in; |
---|
1223 | out -= strm->avail_out; |
---|
1224 | strm->total_in += in; |
---|
1225 | strm->total_out += out; |
---|
1226 | state->total += out; |
---|
1227 | if (state->wrap && out) |
---|
1228 | strm->adler = state->check = |
---|
1229 | UPDATE(state->check, strm->next_out - out, out); |
---|
1230 | strm->data_type = state->bits + (state->last ? 64 : 0) + |
---|
1231 | (state->mode == TYPE ? 128 : 0) + |
---|
1232 | (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0); |
---|
1233 | if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) |
---|
1234 | ret = Z_BUF_ERROR; |
---|
1235 | return ret; |
---|
1236 | } |
---|
1237 | |
---|
1238 | int ZEXPORT inflateEnd(strm) |
---|
1239 | z_streamp strm; |
---|
1240 | { |
---|
1241 | struct inflate_state FAR *state; |
---|
1242 | if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) |
---|
1243 | return Z_STREAM_ERROR; |
---|
1244 | state = (struct inflate_state FAR *)strm->state; |
---|
1245 | if (state->window != Z_NULL) ZFREE(strm, state->window); |
---|
1246 | ZFREE(strm, strm->state); |
---|
1247 | strm->state = Z_NULL; |
---|
1248 | Tracev((stderr, "inflate: end\n")); |
---|
1249 | return Z_OK; |
---|
1250 | } |
---|
1251 | |
---|
1252 | int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength) |
---|
1253 | z_streamp strm; |
---|
1254 | const Bytef *dictionary; |
---|
1255 | uInt dictLength; |
---|
1256 | { |
---|
1257 | struct inflate_state FAR *state; |
---|
1258 | unsigned long id; |
---|
1259 | |
---|
1260 | /* check state */ |
---|
1261 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
1262 | state = (struct inflate_state FAR *)strm->state; |
---|
1263 | if (state->wrap != 0 && state->mode != DICT) |
---|
1264 | return Z_STREAM_ERROR; |
---|
1265 | |
---|
1266 | /* check for correct dictionary id */ |
---|
1267 | if (state->mode == DICT) { |
---|
1268 | id = adler32(0L, Z_NULL, 0); |
---|
1269 | id = adler32(id, dictionary, dictLength); |
---|
1270 | if (id != state->check) |
---|
1271 | return Z_DATA_ERROR; |
---|
1272 | } |
---|
1273 | |
---|
1274 | /* copy dictionary to window */ |
---|
1275 | if (updatewindow(strm, strm->avail_out)) { |
---|
1276 | state->mode = MEM; |
---|
1277 | return Z_MEM_ERROR; |
---|
1278 | } |
---|
1279 | if (dictLength > state->wsize) { |
---|
1280 | zmemcpy(state->window, dictionary + dictLength - state->wsize, |
---|
1281 | state->wsize); |
---|
1282 | state->whave = state->wsize; |
---|
1283 | } |
---|
1284 | else { |
---|
1285 | zmemcpy(state->window + state->wsize - dictLength, dictionary, |
---|
1286 | dictLength); |
---|
1287 | state->whave = dictLength; |
---|
1288 | } |
---|
1289 | state->havedict = 1; |
---|
1290 | Tracev((stderr, "inflate: dictionary set\n")); |
---|
1291 | return Z_OK; |
---|
1292 | } |
---|
1293 | |
---|
1294 | int ZEXPORT inflateGetHeader(strm, head) |
---|
1295 | z_streamp strm; |
---|
1296 | gz_headerp head; |
---|
1297 | { |
---|
1298 | struct inflate_state FAR *state; |
---|
1299 | |
---|
1300 | /* check state */ |
---|
1301 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
1302 | state = (struct inflate_state FAR *)strm->state; |
---|
1303 | if ((state->wrap & 2) == 0) return Z_STREAM_ERROR; |
---|
1304 | |
---|
1305 | /* save header structure */ |
---|
1306 | state->head = head; |
---|
1307 | head->done = 0; |
---|
1308 | return Z_OK; |
---|
1309 | } |
---|
1310 | |
---|
1311 | /* |
---|
1312 | Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found |
---|
1313 | or when out of input. When called, *have is the number of pattern bytes |
---|
1314 | found in order so far, in 0..3. On return *have is updated to the new |
---|
1315 | state. If on return *have equals four, then the pattern was found and the |
---|
1316 | return value is how many bytes were read including the last byte of the |
---|
1317 | pattern. If *have is less than four, then the pattern has not been found |
---|
1318 | yet and the return value is len. In the latter case, syncsearch() can be |
---|
1319 | called again with more data and the *have state. *have is initialized to |
---|
1320 | zero for the first call. |
---|
1321 | */ |
---|
1322 | local unsigned syncsearch(have, buf, len) |
---|
1323 | unsigned FAR *have; |
---|
1324 | unsigned char FAR *buf; |
---|
1325 | unsigned len; |
---|
1326 | { |
---|
1327 | unsigned got; |
---|
1328 | unsigned next; |
---|
1329 | |
---|
1330 | got = *have; |
---|
1331 | next = 0; |
---|
1332 | while (next < len && got < 4) { |
---|
1333 | if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) |
---|
1334 | got++; |
---|
1335 | else if (buf[next]) |
---|
1336 | got = 0; |
---|
1337 | else |
---|
1338 | got = 4 - got; |
---|
1339 | next++; |
---|
1340 | } |
---|
1341 | *have = got; |
---|
1342 | return next; |
---|
1343 | } |
---|
1344 | |
---|
1345 | int ZEXPORT inflateSync(strm) |
---|
1346 | z_streamp strm; |
---|
1347 | { |
---|
1348 | unsigned len; /* number of bytes to look at or looked at */ |
---|
1349 | unsigned long in, out; /* temporary to save total_in and total_out */ |
---|
1350 | unsigned char buf[4]; /* to restore bit buffer to byte string */ |
---|
1351 | struct inflate_state FAR *state; |
---|
1352 | |
---|
1353 | /* check parameters */ |
---|
1354 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
1355 | state = (struct inflate_state FAR *)strm->state; |
---|
1356 | if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; |
---|
1357 | |
---|
1358 | /* if first time, start search in bit buffer */ |
---|
1359 | if (state->mode != SYNC) { |
---|
1360 | state->mode = SYNC; |
---|
1361 | state->hold <<= state->bits & 7; |
---|
1362 | state->bits -= state->bits & 7; |
---|
1363 | len = 0; |
---|
1364 | while (state->bits >= 8) { |
---|
1365 | buf[len++] = (unsigned char)(state->hold); |
---|
1366 | state->hold >>= 8; |
---|
1367 | state->bits -= 8; |
---|
1368 | } |
---|
1369 | state->have = 0; |
---|
1370 | syncsearch(&(state->have), buf, len); |
---|
1371 | } |
---|
1372 | |
---|
1373 | /* search available input */ |
---|
1374 | len = syncsearch(&(state->have), strm->next_in, strm->avail_in); |
---|
1375 | strm->avail_in -= len; |
---|
1376 | strm->next_in += len; |
---|
1377 | strm->total_in += len; |
---|
1378 | |
---|
1379 | /* return no joy or set up to restart inflate() on a new block */ |
---|
1380 | if (state->have != 4) return Z_DATA_ERROR; |
---|
1381 | in = strm->total_in; out = strm->total_out; |
---|
1382 | inflateReset(strm); |
---|
1383 | strm->total_in = in; strm->total_out = out; |
---|
1384 | state->mode = TYPE; |
---|
1385 | return Z_OK; |
---|
1386 | } |
---|
1387 | |
---|
1388 | /* |
---|
1389 | Returns true if inflate is currently at the end of a block generated by |
---|
1390 | Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP |
---|
1391 | implementation to provide an additional safety check. PPP uses |
---|
1392 | Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored |
---|
1393 | block. When decompressing, PPP checks that at the end of input packet, |
---|
1394 | inflate is waiting for these length bytes. |
---|
1395 | */ |
---|
1396 | int ZEXPORT inflateSyncPoint(strm) |
---|
1397 | z_streamp strm; |
---|
1398 | { |
---|
1399 | struct inflate_state FAR *state; |
---|
1400 | |
---|
1401 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
1402 | state = (struct inflate_state FAR *)strm->state; |
---|
1403 | return state->mode == STORED && state->bits == 0; |
---|
1404 | } |
---|
1405 | |
---|
1406 | int ZEXPORT inflateCopy(dest, source) |
---|
1407 | z_streamp dest; |
---|
1408 | z_streamp source; |
---|
1409 | { |
---|
1410 | struct inflate_state FAR *state; |
---|
1411 | struct inflate_state FAR *copy; |
---|
1412 | unsigned char FAR *window; |
---|
1413 | unsigned wsize; |
---|
1414 | |
---|
1415 | /* check input */ |
---|
1416 | if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL || |
---|
1417 | source->zalloc == (alloc_func)0 || source->zfree == (free_func)0) |
---|
1418 | return Z_STREAM_ERROR; |
---|
1419 | state = (struct inflate_state FAR *)source->state; |
---|
1420 | |
---|
1421 | /* allocate space */ |
---|
1422 | copy = (struct inflate_state FAR *) |
---|
1423 | ZALLOC(source, 1, sizeof(struct inflate_state)); |
---|
1424 | if (copy == Z_NULL) return Z_MEM_ERROR; |
---|
1425 | window = Z_NULL; |
---|
1426 | if (state->window != Z_NULL) { |
---|
1427 | window = (unsigned char FAR *) |
---|
1428 | ZALLOC(source, 1U << state->wbits, sizeof(unsigned char)); |
---|
1429 | if (window == Z_NULL) { |
---|
1430 | ZFREE(source, copy); |
---|
1431 | return Z_MEM_ERROR; |
---|
1432 | } |
---|
1433 | } |
---|
1434 | |
---|
1435 | /* copy state */ |
---|
1436 | zmemcpy(dest, source, sizeof(z_stream)); |
---|
1437 | zmemcpy(copy, state, sizeof(struct inflate_state)); |
---|
1438 | if (state->lencode >= state->codes && |
---|
1439 | state->lencode <= state->codes + ENOUGH - 1) { |
---|
1440 | copy->lencode = copy->codes + (state->lencode - state->codes); |
---|
1441 | copy->distcode = copy->codes + (state->distcode - state->codes); |
---|
1442 | } |
---|
1443 | copy->next = copy->codes + (state->next - state->codes); |
---|
1444 | if (window != Z_NULL) { |
---|
1445 | wsize = 1U << state->wbits; |
---|
1446 | zmemcpy(window, state->window, wsize); |
---|
1447 | } |
---|
1448 | copy->window = window; |
---|
1449 | dest->state = (struct internal_state FAR *)copy; |
---|
1450 | return Z_OK; |
---|
1451 | } |
---|
1452 | |
---|
1453 | int ZEXPORT inflateUndermine(strm, subvert) |
---|
1454 | z_streamp strm; |
---|
1455 | int subvert; |
---|
1456 | { |
---|
1457 | struct inflate_state FAR *state; |
---|
1458 | |
---|
1459 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
1460 | state = (struct inflate_state FAR *)strm->state; |
---|
1461 | state->sane = !subvert; |
---|
1462 | #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR |
---|
1463 | return Z_OK; |
---|
1464 | #else |
---|
1465 | state->sane = 1; |
---|
1466 | return Z_DATA_ERROR; |
---|
1467 | #endif |
---|
1468 | } |
---|
1469 | |
---|
1470 | long ZEXPORT inflateMark(strm) |
---|
1471 | z_streamp strm; |
---|
1472 | { |
---|
1473 | struct inflate_state FAR *state; |
---|
1474 | |
---|
1475 | if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16; |
---|
1476 | state = (struct inflate_state FAR *)strm->state; |
---|
1477 | return ((long)(state->back) << 16) + |
---|
1478 | (state->mode == COPY ? state->length : |
---|
1479 | (state->mode == MATCH ? state->was - state->length : 0)); |
---|
1480 | } |
---|