1 | /* |
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2 | * This file is derived from various .h and .c files from the zlib-1.0.4 |
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3 | * distribution by Jean-loup Gailly and Mark Adler, with some additions |
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4 | * by Paul Mackerras to aid in implementing Deflate compression and |
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5 | * decompression for PPP packets. See zlib.h for conditions of |
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6 | * distribution and use. |
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7 | * |
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8 | * Changes that have been made include: |
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9 | * - added Z_PACKET_FLUSH (see zlib.h for details) |
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10 | * - added inflateIncomp and deflateOutputPending |
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11 | * - allow strm->next_out to be NULL, meaning discard the output |
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12 | * |
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13 | * $Id$ |
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14 | */ |
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15 | |
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16 | /* |
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17 | * ==FILEVERSION 971210== |
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18 | * |
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19 | * This marker is used by the Linux installation script to determine |
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20 | * whether an up-to-date version of this file is already installed. |
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21 | */ |
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22 | |
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23 | #define NO_DUMMY_DECL |
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24 | #define NO_ZCFUNCS |
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25 | #define MY_ZCALLOC |
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26 | |
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27 | #if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL)) |
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28 | #define inflate inflate_ppp /* FreeBSD already has an inflate :-( */ |
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29 | #endif |
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30 | |
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31 | |
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32 | /* +++ zutil.h */ |
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33 | /* zutil.h -- internal interface and configuration of the compression library |
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34 | * Copyright (C) 1995-1996 Jean-loup Gailly. |
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35 | * For conditions of distribution and use, see copyright notice in zlib.h |
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36 | */ |
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37 | |
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38 | /* WARNING: this file should *not* be used by applications. It is |
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39 | part of the implementation of the compression library and is |
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40 | subject to change. Applications should only use zlib.h. |
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41 | */ |
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42 | |
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43 | /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */ |
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44 | |
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45 | #ifndef _Z_UTIL_H |
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46 | #define _Z_UTIL_H |
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47 | |
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48 | #include "zlib.h" |
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49 | |
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50 | #if defined(KERNEL) || defined(_KERNEL) |
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51 | /* Assume this is a *BSD or SVR4 kernel */ |
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52 | #include <sys/types.h> |
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53 | #include <sys/time.h> |
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54 | #include <sys/systm.h> |
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55 | #undef u |
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56 | # define HAVE_MEMCPY |
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57 | # define memcpy(d, s, n) bcopy((s), (d), (n)) |
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58 | # define memset(d, v, n) bzero((d), (n)) |
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59 | # define memcmp bcmp |
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60 | |
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61 | #else |
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62 | #if defined(__KERNEL__) |
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63 | /* Assume this is a Linux kernel */ |
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64 | #include <linux/string.h> |
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65 | #define HAVE_MEMCPY |
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66 | |
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67 | #else /* not kernel */ |
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68 | |
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69 | #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS) |
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70 | # include <stddef.h> |
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71 | # include <errno.h> |
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72 | #else |
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73 | extern int errno; |
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74 | #endif |
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75 | #ifdef STDC |
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76 | # include <string.h> |
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77 | # include <stdlib.h> |
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78 | #endif |
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79 | #endif /* __KERNEL__ */ |
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80 | #endif /* _KERNEL || KERNEL */ |
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81 | |
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82 | #ifndef local |
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83 | # define local static |
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84 | #endif |
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85 | /* compile with -Dlocal if your debugger can't find static symbols */ |
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86 | |
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87 | typedef unsigned char uch; |
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88 | typedef uch FAR uchf; |
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89 | typedef unsigned short ush; |
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90 | typedef ush FAR ushf; |
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91 | typedef unsigned long ulg; |
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92 | |
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93 | extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */ |
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94 | /* (size given to avoid silly warnings with Visual C++) */ |
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95 | |
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96 | #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] |
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97 | |
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98 | #define ERR_RETURN(strm,err) \ |
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99 | return (strm->msg = (char*)ERR_MSG(err), (err)) |
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100 | /* To be used only when the state is known to be valid */ |
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101 | |
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102 | /* common constants */ |
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103 | |
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104 | #ifndef DEF_WBITS |
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105 | # define DEF_WBITS MAX_WBITS |
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106 | #endif |
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107 | /* default windowBits for decompression. MAX_WBITS is for compression only */ |
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108 | |
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109 | #if MAX_MEM_LEVEL >= 8 |
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110 | # define DEF_MEM_LEVEL 8 |
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111 | #else |
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112 | # define DEF_MEM_LEVEL MAX_MEM_LEVEL |
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113 | #endif |
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114 | /* default memLevel */ |
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115 | |
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116 | #define STORED_BLOCK 0 |
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117 | #define STATIC_TREES 1 |
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118 | #define DYN_TREES 2 |
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119 | /* The three kinds of block type */ |
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120 | |
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121 | #define MIN_MATCH 3 |
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122 | #define MAX_MATCH 258 |
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123 | /* The minimum and maximum match lengths */ |
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124 | |
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125 | #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */ |
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126 | |
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127 | /* target dependencies */ |
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128 | |
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129 | #ifdef MSDOS |
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130 | # define OS_CODE 0x00 |
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131 | # ifdef __TURBOC__ |
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132 | # include <alloc.h> |
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133 | # else /* MSC or DJGPP */ |
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134 | # include <malloc.h> |
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135 | # endif |
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136 | #endif |
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137 | |
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138 | #ifdef OS2 |
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139 | # define OS_CODE 0x06 |
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140 | #endif |
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141 | |
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142 | #ifdef WIN32 /* Window 95 & Windows NT */ |
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143 | # define OS_CODE 0x0b |
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144 | #endif |
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145 | |
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146 | #if defined(VAXC) || defined(VMS) |
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147 | # define OS_CODE 0x02 |
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148 | # define FOPEN(name, mode) \ |
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149 | fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") |
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150 | #endif |
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151 | |
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152 | #ifdef AMIGA |
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153 | # define OS_CODE 0x01 |
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154 | #endif |
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155 | |
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156 | #if defined(ATARI) || defined(atarist) |
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157 | # define OS_CODE 0x05 |
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158 | #endif |
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159 | |
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160 | #ifdef MACOS |
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161 | # define OS_CODE 0x07 |
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162 | #endif |
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163 | |
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164 | #ifdef __50SERIES /* Prime/PRIMOS */ |
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165 | # define OS_CODE 0x0F |
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166 | #endif |
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167 | |
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168 | #ifdef TOPS20 |
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169 | # define OS_CODE 0x0a |
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170 | #endif |
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171 | |
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172 | #if defined(_BEOS_) || defined(RISCOS) |
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173 | # define fdopen(fd,mode) NULL /* No fdopen() */ |
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174 | #endif |
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175 | |
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176 | /* Common defaults */ |
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177 | |
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178 | #ifndef OS_CODE |
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179 | # define OS_CODE 0x03 /* assume Unix */ |
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180 | #endif |
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181 | |
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182 | #ifndef FOPEN |
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183 | # define FOPEN(name, mode) fopen((name), (mode)) |
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184 | #endif |
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185 | |
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186 | /* functions */ |
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187 | |
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188 | #ifdef HAVE_STRERROR |
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189 | extern char *strerror OF((int)); |
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190 | # define zstrerror(errnum) strerror(errnum) |
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191 | #else |
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192 | # define zstrerror(errnum) "" |
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193 | #endif |
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194 | |
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195 | #if defined(pyr) |
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196 | # define NO_MEMCPY |
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197 | #endif |
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198 | #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER) |
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199 | /* Use our own functions for small and medium model with MSC <= 5.0. |
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200 | * You may have to use the same strategy for Borland C (untested). |
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201 | */ |
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202 | # define NO_MEMCPY |
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203 | #endif |
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204 | #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) |
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205 | # define HAVE_MEMCPY |
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206 | #endif |
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207 | #ifdef HAVE_MEMCPY |
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208 | # ifdef SMALL_MEDIUM /* MSDOS small or medium model */ |
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209 | # define zmemcpy _fmemcpy |
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210 | # define zmemcmp _fmemcmp |
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211 | # define zmemzero(dest, len) _fmemset(dest, 0, len) |
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212 | # else |
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213 | # define zmemcpy memcpy |
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214 | # define zmemcmp memcmp |
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215 | # define zmemzero(dest, len) memset(dest, 0, len) |
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216 | # endif |
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217 | #else |
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218 | extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); |
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219 | extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len)); |
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220 | extern void zmemzero OF((Bytef* dest, uInt len)); |
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221 | #endif |
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222 | |
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223 | /* Diagnostic functions */ |
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224 | #ifdef DEBUG_ZLIB |
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225 | # include <stdio.h> |
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226 | # ifndef verbose |
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227 | # define verbose 0 |
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228 | # endif |
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229 | extern void z_error OF((char *m)); |
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230 | # define Assert(cond,msg) {if(!(cond)) z_error(msg);} |
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231 | # define Trace(x) fprintf x |
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232 | # define Tracev(x) {if (verbose) fprintf x ;} |
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233 | # define Tracevv(x) {if (verbose>1) fprintf x ;} |
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234 | # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} |
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235 | # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} |
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236 | #else |
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237 | # define Assert(cond,msg) |
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238 | # define Trace(x) |
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239 | # define Tracev(x) |
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240 | # define Tracevv(x) |
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241 | # define Tracec(c,x) |
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242 | # define Tracecv(c,x) |
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243 | #endif |
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244 | |
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245 | |
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246 | typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len)); |
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247 | |
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248 | voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); |
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249 | void zcfree OF((voidpf opaque, voidpf ptr)); |
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250 | |
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251 | #define ZALLOC(strm, items, size) \ |
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252 | (*((strm)->zalloc))((strm)->opaque, (items), (size)) |
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253 | #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr)) |
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254 | #define TRY_FREE(s, p) {if (p) ZFREE(s, p);} |
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255 | |
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256 | #endif /* _Z_UTIL_H */ |
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257 | /* --- zutil.h */ |
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258 | |
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259 | /* +++ deflate.h */ |
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260 | /* deflate.h -- internal compression state |
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261 | * Copyright (C) 1995-1996 Jean-loup Gailly |
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262 | * For conditions of distribution and use, see copyright notice in zlib.h |
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263 | */ |
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264 | |
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265 | /* WARNING: this file should *not* be used by applications. It is |
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266 | part of the implementation of the compression library and is |
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267 | subject to change. Applications should only use zlib.h. |
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268 | */ |
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269 | |
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270 | /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */ |
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271 | |
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272 | #ifndef _DEFLATE_H |
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273 | #define _DEFLATE_H |
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274 | |
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275 | /* #include "zutil.h" */ |
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276 | |
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277 | /* =========================================================================== |
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278 | * Internal compression state. |
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279 | */ |
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280 | |
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281 | #define LENGTH_CODES 29 |
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282 | /* number of length codes, not counting the special END_BLOCK code */ |
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283 | |
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284 | #define LITERALS 256 |
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285 | /* number of literal bytes 0..255 */ |
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286 | |
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287 | #define L_CODES (LITERALS+1+LENGTH_CODES) |
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288 | /* number of Literal or Length codes, including the END_BLOCK code */ |
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289 | |
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290 | #define D_CODES 30 |
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291 | /* number of distance codes */ |
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292 | |
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293 | #define BL_CODES 19 |
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294 | /* number of codes used to transfer the bit lengths */ |
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295 | |
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296 | #define HEAP_SIZE (2*L_CODES+1) |
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297 | /* maximum heap size */ |
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298 | |
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299 | #define MAX_BITS 15 |
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300 | /* All codes must not exceed MAX_BITS bits */ |
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301 | |
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302 | #define INIT_STATE 42 |
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303 | #define BUSY_STATE 113 |
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304 | #define FINISH_STATE 666 |
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305 | /* Stream status */ |
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306 | |
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307 | |
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308 | /* Data structure describing a single value and its code string. */ |
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309 | typedef struct ct_data_s { |
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310 | union { |
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311 | ush freq; /* frequency count */ |
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312 | ush code; /* bit string */ |
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313 | } fc; |
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314 | union { |
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315 | ush dad; /* father node in Huffman tree */ |
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316 | ush len; /* length of bit string */ |
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317 | } dl; |
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318 | } FAR ct_data; |
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319 | |
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320 | #define Freq fc.freq |
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321 | #define Code fc.code |
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322 | #define Dad dl.dad |
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323 | #define Len dl.len |
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324 | |
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325 | typedef struct static_tree_desc_s static_tree_desc; |
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326 | |
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327 | typedef struct tree_desc_s { |
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328 | ct_data *dyn_tree; /* the dynamic tree */ |
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329 | int max_code; /* largest code with non zero frequency */ |
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330 | static_tree_desc *stat_desc; /* the corresponding static tree */ |
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331 | } FAR tree_desc; |
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332 | |
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333 | typedef ush Pos; |
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334 | typedef Pos FAR Posf; |
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335 | typedef unsigned IPos; |
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336 | |
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337 | /* A Pos is an index in the character window. We use short instead of int to |
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338 | * save space in the various tables. IPos is used only for parameter passing. |
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339 | */ |
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340 | |
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341 | typedef struct deflate_state { |
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342 | z_streamp strm; /* pointer back to this zlib stream */ |
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343 | int status; /* as the name implies */ |
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344 | Bytef *pending_buf; /* output still pending */ |
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345 | ulg pending_buf_size; /* size of pending_buf */ |
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346 | Bytef *pending_out; /* next pending byte to output to the stream */ |
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347 | int pending; /* nb of bytes in the pending buffer */ |
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348 | int noheader; /* suppress zlib header and adler32 */ |
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349 | Byte data_type; /* UNKNOWN, BINARY or ASCII */ |
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350 | Byte method; /* STORED (for zip only) or DEFLATED */ |
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351 | int last_flush; /* value of flush param for previous deflate call */ |
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352 | |
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353 | /* used by deflate.c: */ |
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354 | |
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355 | uInt w_size; /* LZ77 window size (32K by default) */ |
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356 | uInt w_bits; /* log2(w_size) (8..16) */ |
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357 | uInt w_mask; /* w_size - 1 */ |
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358 | |
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359 | Bytef *window; |
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360 | /* Sliding window. Input bytes are read into the second half of the window, |
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361 | * and move to the first half later to keep a dictionary of at least wSize |
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362 | * bytes. With this organization, matches are limited to a distance of |
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363 | * wSize-MAX_MATCH bytes, but this ensures that IO is always |
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364 | * performed with a length multiple of the block size. Also, it limits |
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365 | * the window size to 64K, which is quite useful on MSDOS. |
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366 | * To do: use the user input buffer as sliding window. |
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367 | */ |
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368 | |
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369 | ulg window_size; |
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370 | /* Actual size of window: 2*wSize, except when the user input buffer |
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371 | * is directly used as sliding window. |
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372 | */ |
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373 | |
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374 | Posf *prev; |
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375 | /* Link to older string with same hash index. To limit the size of this |
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376 | * array to 64K, this link is maintained only for the last 32K strings. |
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377 | * An index in this array is thus a window index modulo 32K. |
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378 | */ |
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379 | |
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380 | Posf *head; /* Heads of the hash chains or NIL. */ |
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381 | |
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382 | uInt ins_h; /* hash index of string to be inserted */ |
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383 | uInt hash_size; /* number of elements in hash table */ |
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384 | uInt hash_bits; /* log2(hash_size) */ |
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385 | uInt hash_mask; /* hash_size-1 */ |
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386 | |
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387 | uInt hash_shift; |
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388 | /* Number of bits by which ins_h must be shifted at each input |
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389 | * step. It must be such that after MIN_MATCH steps, the oldest |
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390 | * byte no longer takes part in the hash key, that is: |
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391 | * hash_shift * MIN_MATCH >= hash_bits |
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392 | */ |
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393 | |
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394 | long block_start; |
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395 | /* Window position at the beginning of the current output block. Gets |
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396 | * negative when the window is moved backwards. |
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397 | */ |
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398 | |
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399 | uInt match_length; /* length of best match */ |
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400 | IPos prev_match; /* previous match */ |
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401 | int match_available; /* set if previous match exists */ |
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402 | uInt strstart; /* start of string to insert */ |
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403 | uInt match_start; /* start of matching string */ |
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404 | uInt lookahead; /* number of valid bytes ahead in window */ |
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405 | |
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406 | uInt prev_length; |
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407 | /* Length of the best match at previous step. Matches not greater than this |
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408 | * are discarded. This is used in the lazy match evaluation. |
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409 | */ |
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410 | |
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411 | uInt max_chain_length; |
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412 | /* To speed up deflation, hash chains are never searched beyond this |
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413 | * length. A higher limit improves compression ratio but degrades the |
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414 | * speed. |
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415 | */ |
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416 | |
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417 | uInt max_lazy_match; |
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418 | /* Attempt to find a better match only when the current match is strictly |
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419 | * smaller than this value. This mechanism is used only for compression |
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420 | * levels >= 4. |
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421 | */ |
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422 | # define max_insert_length max_lazy_match |
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423 | /* Insert new strings in the hash table only if the match length is not |
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424 | * greater than this length. This saves time but degrades compression. |
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425 | * max_insert_length is used only for compression levels <= 3. |
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426 | */ |
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427 | |
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428 | int level; /* compression level (1..9) */ |
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429 | int strategy; /* favor or force Huffman coding*/ |
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430 | |
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431 | uInt good_match; |
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432 | /* Use a faster search when the previous match is longer than this */ |
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433 | |
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434 | int nice_match; /* Stop searching when current match exceeds this */ |
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435 | |
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436 | /* used by trees.c: */ |
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437 | /* Didn't use ct_data typedef below to supress compiler warning */ |
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438 | struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ |
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439 | struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ |
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440 | struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ |
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441 | |
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442 | struct tree_desc_s l_desc; /* desc. for literal tree */ |
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443 | struct tree_desc_s d_desc; /* desc. for distance tree */ |
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444 | struct tree_desc_s bl_desc; /* desc. for bit length tree */ |
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445 | |
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446 | ush bl_count[MAX_BITS+1]; |
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447 | /* number of codes at each bit length for an optimal tree */ |
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448 | |
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449 | int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ |
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450 | int heap_len; /* number of elements in the heap */ |
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451 | int heap_max; /* element of largest frequency */ |
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452 | /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. |
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453 | * The same heap array is used to build all trees. |
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454 | */ |
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455 | |
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456 | uch depth[2*L_CODES+1]; |
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457 | /* Depth of each subtree used as tie breaker for trees of equal frequency |
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458 | */ |
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459 | |
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460 | uchf *l_buf; /* buffer for literals or lengths */ |
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461 | |
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462 | uInt lit_bufsize; |
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463 | /* Size of match buffer for literals/lengths. There are 4 reasons for |
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464 | * limiting lit_bufsize to 64K: |
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465 | * - frequencies can be kept in 16 bit counters |
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466 | * - if compression is not successful for the first block, all input |
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467 | * data is still in the window so we can still emit a stored block even |
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468 | * when input comes from standard input. (This can also be done for |
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469 | * all blocks if lit_bufsize is not greater than 32K.) |
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470 | * - if compression is not successful for a file smaller than 64K, we can |
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471 | * even emit a stored file instead of a stored block (saving 5 bytes). |
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472 | * This is applicable only for zip (not gzip or zlib). |
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473 | * - creating new Huffman trees less frequently may not provide fast |
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474 | * adaptation to changes in the input data statistics. (Take for |
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475 | * example a binary file with poorly compressible code followed by |
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476 | * a highly compressible string table.) Smaller buffer sizes give |
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477 | * fast adaptation but have of course the overhead of transmitting |
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478 | * trees more frequently. |
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479 | * - I can't count above 4 |
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480 | */ |
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481 | |
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482 | uInt last_lit; /* running index in l_buf */ |
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483 | |
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484 | ushf *d_buf; |
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485 | /* Buffer for distances. To simplify the code, d_buf and l_buf have |
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486 | * the same number of elements. To use different lengths, an extra flag |
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487 | * array would be necessary. |
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488 | */ |
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489 | |
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490 | ulg opt_len; /* bit length of current block with optimal trees */ |
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491 | ulg static_len; /* bit length of current block with static trees */ |
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492 | ulg compressed_len; /* total bit length of compressed file */ |
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493 | uInt matches; /* number of string matches in current block */ |
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494 | int last_eob_len; /* bit length of EOB code for last block */ |
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495 | |
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496 | #ifdef DEBUG_ZLIB |
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497 | ulg bits_sent; /* bit length of the compressed data */ |
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498 | #endif |
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499 | |
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500 | ush bi_buf; |
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501 | /* Output buffer. bits are inserted starting at the bottom (least |
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502 | * significant bits). |
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503 | */ |
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504 | int bi_valid; |
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505 | /* Number of valid bits in bi_buf. All bits above the last valid bit |
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506 | * are always zero. |
---|
507 | */ |
---|
508 | |
---|
509 | } FAR deflate_state; |
---|
510 | |
---|
511 | /* Output a byte on the stream. |
---|
512 | * IN assertion: there is enough room in pending_buf. |
---|
513 | */ |
---|
514 | #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} |
---|
515 | |
---|
516 | |
---|
517 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) |
---|
518 | /* Minimum amount of lookahead, except at the end of the input file. |
---|
519 | * See deflate.c for comments about the MIN_MATCH+1. |
---|
520 | */ |
---|
521 | |
---|
522 | #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) |
---|
523 | /* In order to simplify the code, particularly on 16 bit machines, match |
---|
524 | * distances are limited to MAX_DIST instead of WSIZE. |
---|
525 | */ |
---|
526 | |
---|
527 | /* in trees.c */ |
---|
528 | void _tr_init OF((deflate_state *s)); |
---|
529 | int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); |
---|
530 | ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, |
---|
531 | int eof)); |
---|
532 | void _tr_align OF((deflate_state *s)); |
---|
533 | void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, |
---|
534 | int eof)); |
---|
535 | void _tr_stored_type_only OF((deflate_state *)); |
---|
536 | |
---|
537 | #endif |
---|
538 | /* --- deflate.h */ |
---|
539 | |
---|
540 | /* +++ deflate.c */ |
---|
541 | /* deflate.c -- compress data using the deflation algorithm |
---|
542 | * Copyright (C) 1995-1996 Jean-loup Gailly. |
---|
543 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
544 | */ |
---|
545 | |
---|
546 | /* |
---|
547 | * ALGORITHM |
---|
548 | * |
---|
549 | * The "deflation" process depends on being able to identify portions |
---|
550 | * of the input text which are identical to earlier input (within a |
---|
551 | * sliding window trailing behind the input currently being processed). |
---|
552 | * |
---|
553 | * The most straightforward technique turns out to be the fastest for |
---|
554 | * most input files: try all possible matches and select the longest. |
---|
555 | * The key feature of this algorithm is that insertions into the string |
---|
556 | * dictionary are very simple and thus fast, and deletions are avoided |
---|
557 | * completely. Insertions are performed at each input character, whereas |
---|
558 | * string matches are performed only when the previous match ends. So it |
---|
559 | * is preferable to spend more time in matches to allow very fast string |
---|
560 | * insertions and avoid deletions. The matching algorithm for small |
---|
561 | * strings is inspired from that of Rabin & Karp. A brute force approach |
---|
562 | * is used to find longer strings when a small match has been found. |
---|
563 | * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze |
---|
564 | * (by Leonid Broukhis). |
---|
565 | * A previous version of this file used a more sophisticated algorithm |
---|
566 | * (by Fiala and Greene) which is guaranteed to run in linear amortized |
---|
567 | * time, but has a larger average cost, uses more memory and is patented. |
---|
568 | * However the F&G algorithm may be faster for some highly redundant |
---|
569 | * files if the parameter max_chain_length (described below) is too large. |
---|
570 | * |
---|
571 | * ACKNOWLEDGEMENTS |
---|
572 | * |
---|
573 | * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and |
---|
574 | * I found it in 'freeze' written by Leonid Broukhis. |
---|
575 | * Thanks to many people for bug reports and testing. |
---|
576 | * |
---|
577 | * REFERENCES |
---|
578 | * |
---|
579 | * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". |
---|
580 | * Available in ftp://ds.internic.net/rfc/rfc1951.txt |
---|
581 | * |
---|
582 | * A description of the Rabin and Karp algorithm is given in the book |
---|
583 | * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. |
---|
584 | * |
---|
585 | * Fiala,E.R., and Greene,D.H. |
---|
586 | * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 |
---|
587 | * |
---|
588 | */ |
---|
589 | |
---|
590 | /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */ |
---|
591 | |
---|
592 | /* #include "deflate.h" */ |
---|
593 | |
---|
594 | char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly "; |
---|
595 | /* |
---|
596 | If you use the zlib library in a product, an acknowledgment is welcome |
---|
597 | in the documentation of your product. If for some reason you cannot |
---|
598 | include such an acknowledgment, I would appreciate that you keep this |
---|
599 | copyright string in the executable of your product. |
---|
600 | */ |
---|
601 | |
---|
602 | /* =========================================================================== |
---|
603 | * Function prototypes. |
---|
604 | */ |
---|
605 | typedef enum { |
---|
606 | need_more, /* block not completed, need more input or more output */ |
---|
607 | block_done, /* block flush performed */ |
---|
608 | finish_started, /* finish started, need only more output at next deflate */ |
---|
609 | finish_done /* finish done, accept no more input or output */ |
---|
610 | } block_state; |
---|
611 | |
---|
612 | typedef block_state (*compress_func) OF((deflate_state *s, int flush)); |
---|
613 | /* Compression function. Returns the block state after the call. */ |
---|
614 | |
---|
615 | local void fill_window OF((deflate_state *s)); |
---|
616 | local block_state deflate_stored OF((deflate_state *s, int flush)); |
---|
617 | local block_state deflate_fast OF((deflate_state *s, int flush)); |
---|
618 | local block_state deflate_slow OF((deflate_state *s, int flush)); |
---|
619 | local void lm_init OF((deflate_state *s)); |
---|
620 | local void putShortMSB OF((deflate_state *s, uInt b)); |
---|
621 | local void flush_pending OF((z_streamp strm)); |
---|
622 | local int read_buf OF((z_streamp strm, charf *buf, unsigned size)); |
---|
623 | #ifdef ASMV |
---|
624 | void match_init OF((void)); /* asm code initialization */ |
---|
625 | uInt longest_match OF((deflate_state *s, IPos cur_match)); |
---|
626 | #else |
---|
627 | local uInt longest_match OF((deflate_state *s, IPos cur_match)); |
---|
628 | #endif |
---|
629 | |
---|
630 | #ifdef DEBUG_ZLIB |
---|
631 | local void check_match OF((deflate_state *s, IPos start, IPos match, |
---|
632 | int length)); |
---|
633 | #endif |
---|
634 | |
---|
635 | /* =========================================================================== |
---|
636 | * Local data |
---|
637 | */ |
---|
638 | |
---|
639 | #define NIL 0 |
---|
640 | /* Tail of hash chains */ |
---|
641 | |
---|
642 | #ifndef TOO_FAR |
---|
643 | # define TOO_FAR 4096 |
---|
644 | #endif |
---|
645 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ |
---|
646 | |
---|
647 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) |
---|
648 | /* Minimum amount of lookahead, except at the end of the input file. |
---|
649 | * See deflate.c for comments about the MIN_MATCH+1. |
---|
650 | */ |
---|
651 | |
---|
652 | /* Values for max_lazy_match, good_match and max_chain_length, depending on |
---|
653 | * the desired pack level (0..9). The values given below have been tuned to |
---|
654 | * exclude worst case performance for pathological files. Better values may be |
---|
655 | * found for specific files. |
---|
656 | */ |
---|
657 | typedef struct config_s { |
---|
658 | ush good_length; /* reduce lazy search above this match length */ |
---|
659 | ush max_lazy; /* do not perform lazy search above this match length */ |
---|
660 | ush nice_length; /* quit search above this match length */ |
---|
661 | ush max_chain; |
---|
662 | compress_func func; |
---|
663 | } config; |
---|
664 | |
---|
665 | local config configuration_table[10] = { |
---|
666 | /* good lazy nice chain */ |
---|
667 | /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ |
---|
668 | /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */ |
---|
669 | /* 2 */ {4, 5, 16, 8, deflate_fast}, |
---|
670 | /* 3 */ {4, 6, 32, 32, deflate_fast}, |
---|
671 | |
---|
672 | /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ |
---|
673 | /* 5 */ {8, 16, 32, 32, deflate_slow}, |
---|
674 | /* 6 */ {8, 16, 128, 128, deflate_slow}, |
---|
675 | /* 7 */ {8, 32, 128, 256, deflate_slow}, |
---|
676 | /* 8 */ {32, 128, 258, 1024, deflate_slow}, |
---|
677 | /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */ |
---|
678 | |
---|
679 | /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 |
---|
680 | * For deflate_fast() (levels <= 3) good is ignored and lazy has a different |
---|
681 | * meaning. |
---|
682 | */ |
---|
683 | |
---|
684 | #define EQUAL 0 |
---|
685 | /* result of memcmp for equal strings */ |
---|
686 | |
---|
687 | #ifndef NO_DUMMY_DECL |
---|
688 | struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ |
---|
689 | #endif |
---|
690 | |
---|
691 | /* =========================================================================== |
---|
692 | * Update a hash value with the given input byte |
---|
693 | * IN assertion: all calls to to UPDATE_HASH are made with consecutive |
---|
694 | * input characters, so that a running hash key can be computed from the |
---|
695 | * previous key instead of complete recalculation each time. |
---|
696 | */ |
---|
697 | #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) |
---|
698 | |
---|
699 | |
---|
700 | /* =========================================================================== |
---|
701 | * Insert string str in the dictionary and set match_head to the previous head |
---|
702 | * of the hash chain (the most recent string with same hash key). Return |
---|
703 | * the previous length of the hash chain. |
---|
704 | * IN assertion: all calls to to INSERT_STRING are made with consecutive |
---|
705 | * input characters and the first MIN_MATCH bytes of str are valid |
---|
706 | * (except for the last MIN_MATCH-1 bytes of the input file). |
---|
707 | */ |
---|
708 | #define INSERT_STRING(s, str, match_head) \ |
---|
709 | (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ |
---|
710 | s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ |
---|
711 | s->head[s->ins_h] = (Pos)(str)) |
---|
712 | |
---|
713 | /* =========================================================================== |
---|
714 | * Initialize the hash table (avoiding 64K overflow for 16 bit systems). |
---|
715 | * prev[] will be initialized on the fly. |
---|
716 | */ |
---|
717 | #define CLEAR_HASH(s) \ |
---|
718 | s->head[s->hash_size-1] = NIL; \ |
---|
719 | zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); |
---|
720 | |
---|
721 | /* ========================================================================= */ |
---|
722 | int deflateInit_(strm, level, version, stream_size) |
---|
723 | z_streamp strm; |
---|
724 | int level; |
---|
725 | const char *version; |
---|
726 | int stream_size; |
---|
727 | { |
---|
728 | return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, |
---|
729 | Z_DEFAULT_STRATEGY, version, stream_size); |
---|
730 | /* To do: ignore strm->next_in if we use it as window */ |
---|
731 | } |
---|
732 | |
---|
733 | /* ========================================================================= */ |
---|
734 | int deflateInit2_(strm, level, method, windowBits, memLevel, strategy, |
---|
735 | version, stream_size) |
---|
736 | z_streamp strm; |
---|
737 | int level; |
---|
738 | int method; |
---|
739 | int windowBits; |
---|
740 | int memLevel; |
---|
741 | int strategy; |
---|
742 | const char *version; |
---|
743 | int stream_size; |
---|
744 | { |
---|
745 | deflate_state *s; |
---|
746 | int noheader = 0; |
---|
747 | static char* my_version = ZLIB_VERSION; |
---|
748 | |
---|
749 | ushf *overlay; |
---|
750 | /* We overlay pending_buf and d_buf+l_buf. This works since the average |
---|
751 | * output size for (length,distance) codes is <= 24 bits. |
---|
752 | */ |
---|
753 | |
---|
754 | if (version == Z_NULL || version[0] != my_version[0] || |
---|
755 | stream_size != sizeof(z_stream)) { |
---|
756 | return Z_VERSION_ERROR; |
---|
757 | } |
---|
758 | if (strm == Z_NULL) return Z_STREAM_ERROR; |
---|
759 | |
---|
760 | strm->msg = Z_NULL; |
---|
761 | #ifndef NO_ZCFUNCS |
---|
762 | if (strm->zalloc == Z_NULL) { |
---|
763 | strm->zalloc = zcalloc; |
---|
764 | strm->opaque = (voidpf)0; |
---|
765 | } |
---|
766 | if (strm->zfree == Z_NULL) strm->zfree = zcfree; |
---|
767 | #endif |
---|
768 | |
---|
769 | if (level == Z_DEFAULT_COMPRESSION) level = 6; |
---|
770 | |
---|
771 | if (windowBits < 0) { /* undocumented feature: suppress zlib header */ |
---|
772 | noheader = 1; |
---|
773 | windowBits = -windowBits; |
---|
774 | } |
---|
775 | if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || |
---|
776 | windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || |
---|
777 | strategy < 0 || strategy > Z_HUFFMAN_ONLY) { |
---|
778 | return Z_STREAM_ERROR; |
---|
779 | } |
---|
780 | s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); |
---|
781 | if (s == Z_NULL) return Z_MEM_ERROR; |
---|
782 | strm->state = (struct internal_state FAR *)s; |
---|
783 | s->strm = strm; |
---|
784 | |
---|
785 | s->noheader = noheader; |
---|
786 | s->w_bits = windowBits; |
---|
787 | s->w_size = 1 << s->w_bits; |
---|
788 | s->w_mask = s->w_size - 1; |
---|
789 | |
---|
790 | s->hash_bits = memLevel + 7; |
---|
791 | s->hash_size = 1 << s->hash_bits; |
---|
792 | s->hash_mask = s->hash_size - 1; |
---|
793 | s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); |
---|
794 | |
---|
795 | s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); |
---|
796 | s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); |
---|
797 | s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); |
---|
798 | |
---|
799 | s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ |
---|
800 | |
---|
801 | overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); |
---|
802 | s->pending_buf = (uchf *) overlay; |
---|
803 | s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); |
---|
804 | |
---|
805 | if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || |
---|
806 | s->pending_buf == Z_NULL) { |
---|
807 | strm->msg = (char*)ERR_MSG(Z_MEM_ERROR); |
---|
808 | deflateEnd (strm); |
---|
809 | return Z_MEM_ERROR; |
---|
810 | } |
---|
811 | s->d_buf = overlay + s->lit_bufsize/sizeof(ush); |
---|
812 | s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; |
---|
813 | |
---|
814 | s->level = level; |
---|
815 | s->strategy = strategy; |
---|
816 | s->method = (Byte)method; |
---|
817 | |
---|
818 | return deflateReset(strm); |
---|
819 | } |
---|
820 | |
---|
821 | /* ========================================================================= */ |
---|
822 | int deflateSetDictionary (strm, dictionary, dictLength) |
---|
823 | z_streamp strm; |
---|
824 | const Bytef *dictionary; |
---|
825 | uInt dictLength; |
---|
826 | { |
---|
827 | deflate_state *s; |
---|
828 | uInt length = dictLength; |
---|
829 | uInt n; |
---|
830 | IPos hash_head = 0; |
---|
831 | |
---|
832 | if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) |
---|
833 | return Z_STREAM_ERROR; |
---|
834 | |
---|
835 | s = (deflate_state *) strm->state; |
---|
836 | if (s->status != INIT_STATE) return Z_STREAM_ERROR; |
---|
837 | |
---|
838 | strm->adler = adler32(strm->adler, dictionary, dictLength); |
---|
839 | |
---|
840 | if (length < MIN_MATCH) return Z_OK; |
---|
841 | if (length > MAX_DIST(s)) { |
---|
842 | length = MAX_DIST(s); |
---|
843 | #ifndef USE_DICT_HEAD |
---|
844 | dictionary += dictLength - length; /* use the tail of the dictionary */ |
---|
845 | #endif |
---|
846 | } |
---|
847 | zmemcpy((charf *)s->window, dictionary, length); |
---|
848 | s->strstart = length; |
---|
849 | s->block_start = (long)length; |
---|
850 | |
---|
851 | /* Insert all strings in the hash table (except for the last two bytes). |
---|
852 | * s->lookahead stays null, so s->ins_h will be recomputed at the next |
---|
853 | * call of fill_window. |
---|
854 | */ |
---|
855 | s->ins_h = s->window[0]; |
---|
856 | UPDATE_HASH(s, s->ins_h, s->window[1]); |
---|
857 | for (n = 0; n <= length - MIN_MATCH; n++) { |
---|
858 | INSERT_STRING(s, n, hash_head); |
---|
859 | } |
---|
860 | if (hash_head) hash_head = 0; /* to make compiler happy */ |
---|
861 | return Z_OK; |
---|
862 | } |
---|
863 | |
---|
864 | /* ========================================================================= */ |
---|
865 | int deflateReset (strm) |
---|
866 | z_streamp strm; |
---|
867 | { |
---|
868 | deflate_state *s; |
---|
869 | |
---|
870 | if (strm == Z_NULL || strm->state == Z_NULL || |
---|
871 | strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; |
---|
872 | |
---|
873 | strm->total_in = strm->total_out = 0; |
---|
874 | strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ |
---|
875 | strm->data_type = Z_UNKNOWN; |
---|
876 | |
---|
877 | s = (deflate_state *)strm->state; |
---|
878 | s->pending = 0; |
---|
879 | s->pending_out = s->pending_buf; |
---|
880 | |
---|
881 | if (s->noheader < 0) { |
---|
882 | s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ |
---|
883 | } |
---|
884 | s->status = s->noheader ? BUSY_STATE : INIT_STATE; |
---|
885 | strm->adler = 1; |
---|
886 | s->last_flush = Z_NO_FLUSH; |
---|
887 | |
---|
888 | _tr_init(s); |
---|
889 | lm_init(s); |
---|
890 | |
---|
891 | return Z_OK; |
---|
892 | } |
---|
893 | |
---|
894 | /* ========================================================================= */ |
---|
895 | int deflateParams(strm, level, strategy) |
---|
896 | z_streamp strm; |
---|
897 | int level; |
---|
898 | int strategy; |
---|
899 | { |
---|
900 | deflate_state *s; |
---|
901 | compress_func func; |
---|
902 | int err = Z_OK; |
---|
903 | |
---|
904 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
905 | s = (deflate_state *) strm->state; |
---|
906 | |
---|
907 | if (level == Z_DEFAULT_COMPRESSION) { |
---|
908 | level = 6; |
---|
909 | } |
---|
910 | if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) { |
---|
911 | return Z_STREAM_ERROR; |
---|
912 | } |
---|
913 | func = configuration_table[s->level].func; |
---|
914 | |
---|
915 | if (func != configuration_table[level].func && strm->total_in != 0) { |
---|
916 | /* Flush the last buffer: */ |
---|
917 | err = deflate(strm, Z_PARTIAL_FLUSH); |
---|
918 | } |
---|
919 | if (s->level != level) { |
---|
920 | s->level = level; |
---|
921 | s->max_lazy_match = configuration_table[level].max_lazy; |
---|
922 | s->good_match = configuration_table[level].good_length; |
---|
923 | s->nice_match = configuration_table[level].nice_length; |
---|
924 | s->max_chain_length = configuration_table[level].max_chain; |
---|
925 | } |
---|
926 | s->strategy = strategy; |
---|
927 | return err; |
---|
928 | } |
---|
929 | |
---|
930 | /* ========================================================================= |
---|
931 | * Put a short in the pending buffer. The 16-bit value is put in MSB order. |
---|
932 | * IN assertion: the stream state is correct and there is enough room in |
---|
933 | * pending_buf. |
---|
934 | */ |
---|
935 | local void putShortMSB (s, b) |
---|
936 | deflate_state *s; |
---|
937 | uInt b; |
---|
938 | { |
---|
939 | put_byte(s, (Byte)(b >> 8)); |
---|
940 | put_byte(s, (Byte)(b & 0xff)); |
---|
941 | } |
---|
942 | |
---|
943 | /* ========================================================================= |
---|
944 | * Flush as much pending output as possible. All deflate() output goes |
---|
945 | * through this function so some applications may wish to modify it |
---|
946 | * to avoid allocating a large strm->next_out buffer and copying into it. |
---|
947 | * (See also read_buf()). |
---|
948 | */ |
---|
949 | local void flush_pending(strm) |
---|
950 | z_streamp strm; |
---|
951 | { |
---|
952 | deflate_state *s = (deflate_state *) strm->state; |
---|
953 | unsigned len = s->pending; |
---|
954 | |
---|
955 | if (len > strm->avail_out) len = strm->avail_out; |
---|
956 | if (len == 0) return; |
---|
957 | |
---|
958 | if (strm->next_out != Z_NULL) { |
---|
959 | zmemcpy(strm->next_out, s->pending_out, len); |
---|
960 | strm->next_out += len; |
---|
961 | } |
---|
962 | s->pending_out += len; |
---|
963 | strm->total_out += len; |
---|
964 | strm->avail_out -= len; |
---|
965 | s->pending -= len; |
---|
966 | if (s->pending == 0) { |
---|
967 | s->pending_out = s->pending_buf; |
---|
968 | } |
---|
969 | } |
---|
970 | |
---|
971 | /* ========================================================================= */ |
---|
972 | int deflate (strm, flush) |
---|
973 | z_streamp strm; |
---|
974 | int flush; |
---|
975 | { |
---|
976 | int old_flush; /* value of flush param for previous deflate call */ |
---|
977 | deflate_state *s; |
---|
978 | |
---|
979 | if (strm == Z_NULL || strm->state == Z_NULL || |
---|
980 | flush > Z_FINISH || flush < 0) { |
---|
981 | return Z_STREAM_ERROR; |
---|
982 | } |
---|
983 | s = (deflate_state *) strm->state; |
---|
984 | |
---|
985 | if ((strm->next_in == Z_NULL && strm->avail_in != 0) || |
---|
986 | (s->status == FINISH_STATE && flush != Z_FINISH)) { |
---|
987 | ERR_RETURN(strm, Z_STREAM_ERROR); |
---|
988 | } |
---|
989 | if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); |
---|
990 | |
---|
991 | s->strm = strm; /* just in case */ |
---|
992 | old_flush = s->last_flush; |
---|
993 | s->last_flush = flush; |
---|
994 | |
---|
995 | /* Write the zlib header */ |
---|
996 | if (s->status == INIT_STATE) { |
---|
997 | |
---|
998 | uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; |
---|
999 | uInt level_flags = (s->level-1) >> 1; |
---|
1000 | |
---|
1001 | if (level_flags > 3) level_flags = 3; |
---|
1002 | header |= (level_flags << 6); |
---|
1003 | if (s->strstart != 0) header |= PRESET_DICT; |
---|
1004 | header += 31 - (header % 31); |
---|
1005 | |
---|
1006 | s->status = BUSY_STATE; |
---|
1007 | putShortMSB(s, header); |
---|
1008 | |
---|
1009 | /* Save the adler32 of the preset dictionary: */ |
---|
1010 | if (s->strstart != 0) { |
---|
1011 | putShortMSB(s, (uInt)(strm->adler >> 16)); |
---|
1012 | putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
---|
1013 | } |
---|
1014 | strm->adler = 1L; |
---|
1015 | } |
---|
1016 | |
---|
1017 | /* Flush as much pending output as possible */ |
---|
1018 | if (s->pending != 0) { |
---|
1019 | flush_pending(strm); |
---|
1020 | if (strm->avail_out == 0) { |
---|
1021 | /* Since avail_out is 0, deflate will be called again with |
---|
1022 | * more output space, but possibly with both pending and |
---|
1023 | * avail_in equal to zero. There won't be anything to do, |
---|
1024 | * but this is not an error situation so make sure we |
---|
1025 | * return OK instead of BUF_ERROR at next call of deflate: |
---|
1026 | */ |
---|
1027 | s->last_flush = -1; |
---|
1028 | return Z_OK; |
---|
1029 | } |
---|
1030 | |
---|
1031 | /* Make sure there is something to do and avoid duplicate consecutive |
---|
1032 | * flushes. For repeated and useless calls with Z_FINISH, we keep |
---|
1033 | * returning Z_STREAM_END instead of Z_BUFF_ERROR. |
---|
1034 | */ |
---|
1035 | } else if (strm->avail_in == 0 && flush <= old_flush && |
---|
1036 | flush != Z_FINISH) { |
---|
1037 | ERR_RETURN(strm, Z_BUF_ERROR); |
---|
1038 | } |
---|
1039 | |
---|
1040 | /* User must not provide more input after the first FINISH: */ |
---|
1041 | if (s->status == FINISH_STATE && strm->avail_in != 0) { |
---|
1042 | ERR_RETURN(strm, Z_BUF_ERROR); |
---|
1043 | } |
---|
1044 | |
---|
1045 | /* Start a new block or continue the current one. |
---|
1046 | */ |
---|
1047 | if (strm->avail_in != 0 || s->lookahead != 0 || |
---|
1048 | (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { |
---|
1049 | block_state bstate; |
---|
1050 | |
---|
1051 | bstate = (*(configuration_table[s->level].func))(s, flush); |
---|
1052 | |
---|
1053 | if (bstate == finish_started || bstate == finish_done) { |
---|
1054 | s->status = FINISH_STATE; |
---|
1055 | } |
---|
1056 | if (bstate == need_more || bstate == finish_started) { |
---|
1057 | if (strm->avail_out == 0) { |
---|
1058 | s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ |
---|
1059 | } |
---|
1060 | return Z_OK; |
---|
1061 | /* If flush != Z_NO_FLUSH && avail_out == 0, the next call |
---|
1062 | * of deflate should use the same flush parameter to make sure |
---|
1063 | * that the flush is complete. So we don't have to output an |
---|
1064 | * empty block here, this will be done at next call. This also |
---|
1065 | * ensures that for a very small output buffer, we emit at most |
---|
1066 | * one empty block. |
---|
1067 | */ |
---|
1068 | } |
---|
1069 | if (bstate == block_done) { |
---|
1070 | if (flush == Z_PARTIAL_FLUSH) { |
---|
1071 | _tr_align(s); |
---|
1072 | } else if (flush == Z_PACKET_FLUSH) { |
---|
1073 | /* Output just the 3-bit `stored' block type value, |
---|
1074 | but not a zero length. */ |
---|
1075 | _tr_stored_type_only(s); |
---|
1076 | } else { /* FULL_FLUSH or SYNC_FLUSH */ |
---|
1077 | _tr_stored_block(s, (char*)0, 0L, 0); |
---|
1078 | /* For a full flush, this empty block will be recognized |
---|
1079 | * as a special marker by inflate_sync(). |
---|
1080 | */ |
---|
1081 | if (flush == Z_FULL_FLUSH) { |
---|
1082 | CLEAR_HASH(s); /* forget history */ |
---|
1083 | } |
---|
1084 | } |
---|
1085 | flush_pending(strm); |
---|
1086 | if (strm->avail_out == 0) { |
---|
1087 | s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ |
---|
1088 | return Z_OK; |
---|
1089 | } |
---|
1090 | } |
---|
1091 | } |
---|
1092 | Assert(strm->avail_out > 0, "bug2"); |
---|
1093 | |
---|
1094 | if (flush != Z_FINISH) return Z_OK; |
---|
1095 | if (s->noheader) return Z_STREAM_END; |
---|
1096 | |
---|
1097 | /* Write the zlib trailer (adler32) */ |
---|
1098 | putShortMSB(s, (uInt)(strm->adler >> 16)); |
---|
1099 | putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
---|
1100 | flush_pending(strm); |
---|
1101 | /* If avail_out is zero, the application will call deflate again |
---|
1102 | * to flush the rest. |
---|
1103 | */ |
---|
1104 | s->noheader = -1; /* write the trailer only once! */ |
---|
1105 | return s->pending != 0 ? Z_OK : Z_STREAM_END; |
---|
1106 | } |
---|
1107 | |
---|
1108 | /* ========================================================================= */ |
---|
1109 | int deflateEnd (strm) |
---|
1110 | z_streamp strm; |
---|
1111 | { |
---|
1112 | int status; |
---|
1113 | deflate_state *s; |
---|
1114 | |
---|
1115 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
---|
1116 | s = (deflate_state *) strm->state; |
---|
1117 | |
---|
1118 | status = s->status; |
---|
1119 | if (status != INIT_STATE && status != BUSY_STATE && |
---|
1120 | status != FINISH_STATE) { |
---|
1121 | return Z_STREAM_ERROR; |
---|
1122 | } |
---|
1123 | |
---|
1124 | /* Deallocate in reverse order of allocations: */ |
---|
1125 | TRY_FREE(strm, s->pending_buf); |
---|
1126 | TRY_FREE(strm, s->head); |
---|
1127 | TRY_FREE(strm, s->prev); |
---|
1128 | TRY_FREE(strm, s->window); |
---|
1129 | |
---|
1130 | ZFREE(strm, s); |
---|
1131 | strm->state = Z_NULL; |
---|
1132 | |
---|
1133 | return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; |
---|
1134 | } |
---|
1135 | |
---|
1136 | /* ========================================================================= |
---|
1137 | * Copy the source state to the destination state. |
---|
1138 | */ |
---|
1139 | int deflateCopy (dest, source) |
---|
1140 | z_streamp dest; |
---|
1141 | z_streamp source; |
---|
1142 | { |
---|
1143 | deflate_state *ds; |
---|
1144 | deflate_state *ss; |
---|
1145 | ushf *overlay; |
---|
1146 | |
---|
1147 | if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) |
---|
1148 | return Z_STREAM_ERROR; |
---|
1149 | ss = (deflate_state *) source->state; |
---|
1150 | |
---|
1151 | zmemcpy(dest, source, sizeof(*dest)); |
---|
1152 | |
---|
1153 | ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); |
---|
1154 | if (ds == Z_NULL) return Z_MEM_ERROR; |
---|
1155 | dest->state = (struct internal_state FAR *) ds; |
---|
1156 | zmemcpy(ds, ss, sizeof(*ds)); |
---|
1157 | ds->strm = dest; |
---|
1158 | |
---|
1159 | ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); |
---|
1160 | ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); |
---|
1161 | ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); |
---|
1162 | overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); |
---|
1163 | ds->pending_buf = (uchf *) overlay; |
---|
1164 | |
---|
1165 | if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || |
---|
1166 | ds->pending_buf == Z_NULL) { |
---|
1167 | deflateEnd (dest); |
---|
1168 | return Z_MEM_ERROR; |
---|
1169 | } |
---|
1170 | /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ |
---|
1171 | zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); |
---|
1172 | zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); |
---|
1173 | zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); |
---|
1174 | zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); |
---|
1175 | |
---|
1176 | ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); |
---|
1177 | ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); |
---|
1178 | ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; |
---|
1179 | |
---|
1180 | ds->l_desc.dyn_tree = ds->dyn_ltree; |
---|
1181 | ds->d_desc.dyn_tree = ds->dyn_dtree; |
---|
1182 | ds->bl_desc.dyn_tree = ds->bl_tree; |
---|
1183 | |
---|
1184 | return Z_OK; |
---|
1185 | } |
---|
1186 | |
---|
1187 | /* =========================================================================== |
---|
1188 | * Return the number of bytes of output which are immediately available |
---|
1189 | * for output from the decompressor. |
---|
1190 | */ |
---|
1191 | int deflateOutputPending (strm) |
---|
1192 | z_streamp strm; |
---|
1193 | { |
---|
1194 | if (strm == Z_NULL || strm->state == Z_NULL) return 0; |
---|
1195 | |
---|
1196 | return ((deflate_state *)(strm->state))->pending; |
---|
1197 | } |
---|
1198 | |
---|
1199 | /* =========================================================================== |
---|
1200 | * Read a new buffer from the current input stream, update the adler32 |
---|
1201 | * and total number of bytes read. All deflate() input goes through |
---|
1202 | * this function so some applications may wish to modify it to avoid |
---|
1203 | * allocating a large strm->next_in buffer and copying from it. |
---|
1204 | * (See also flush_pending()). |
---|
1205 | */ |
---|
1206 | local int read_buf(strm, buf, size) |
---|
1207 | z_streamp strm; |
---|
1208 | charf *buf; |
---|
1209 | unsigned size; |
---|
1210 | { |
---|
1211 | unsigned len = strm->avail_in; |
---|
1212 | |
---|
1213 | if (len > size) len = size; |
---|
1214 | if (len == 0) return 0; |
---|
1215 | |
---|
1216 | strm->avail_in -= len; |
---|
1217 | |
---|
1218 | if (!((deflate_state *)(strm->state))->noheader) { |
---|
1219 | strm->adler = adler32(strm->adler, strm->next_in, len); |
---|
1220 | } |
---|
1221 | zmemcpy(buf, strm->next_in, len); |
---|
1222 | strm->next_in += len; |
---|
1223 | strm->total_in += len; |
---|
1224 | |
---|
1225 | return (int)len; |
---|
1226 | } |
---|
1227 | |
---|
1228 | /* =========================================================================== |
---|
1229 | * Initialize the "longest match" routines for a new zlib stream |
---|
1230 | */ |
---|
1231 | local void lm_init (s) |
---|
1232 | deflate_state *s; |
---|
1233 | { |
---|
1234 | s->window_size = (ulg)2L*s->w_size; |
---|
1235 | |
---|
1236 | CLEAR_HASH(s); |
---|
1237 | |
---|
1238 | /* Set the default configuration parameters: |
---|
1239 | */ |
---|
1240 | s->max_lazy_match = configuration_table[s->level].max_lazy; |
---|
1241 | s->good_match = configuration_table[s->level].good_length; |
---|
1242 | s->nice_match = configuration_table[s->level].nice_length; |
---|
1243 | s->max_chain_length = configuration_table[s->level].max_chain; |
---|
1244 | |
---|
1245 | s->strstart = 0; |
---|
1246 | s->block_start = 0L; |
---|
1247 | s->lookahead = 0; |
---|
1248 | s->match_length = s->prev_length = MIN_MATCH-1; |
---|
1249 | s->match_available = 0; |
---|
1250 | s->ins_h = 0; |
---|
1251 | #ifdef ASMV |
---|
1252 | match_init(); /* initialize the asm code */ |
---|
1253 | #endif |
---|
1254 | } |
---|
1255 | |
---|
1256 | /* =========================================================================== |
---|
1257 | * Set match_start to the longest match starting at the given string and |
---|
1258 | * return its length. Matches shorter or equal to prev_length are discarded, |
---|
1259 | * in which case the result is equal to prev_length and match_start is |
---|
1260 | * garbage. |
---|
1261 | * IN assertions: cur_match is the head of the hash chain for the current |
---|
1262 | * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 |
---|
1263 | * OUT assertion: the match length is not greater than s->lookahead. |
---|
1264 | */ |
---|
1265 | #ifndef ASMV |
---|
1266 | /* For 80x86 and 680x0, an optimized version will be provided in match.asm or |
---|
1267 | * match.S. The code will be functionally equivalent. |
---|
1268 | */ |
---|
1269 | local uInt longest_match(s, cur_match) |
---|
1270 | deflate_state *s; |
---|
1271 | IPos cur_match; /* current match */ |
---|
1272 | { |
---|
1273 | unsigned chain_length = s->max_chain_length;/* max hash chain length */ |
---|
1274 | register Bytef *scan = s->window + s->strstart; /* current string */ |
---|
1275 | register Bytef *match; /* matched string */ |
---|
1276 | register int len; /* length of current match */ |
---|
1277 | int best_len = s->prev_length; /* best match length so far */ |
---|
1278 | int nice_match = s->nice_match; /* stop if match long enough */ |
---|
1279 | IPos limit = s->strstart > (IPos)MAX_DIST(s) ? |
---|
1280 | s->strstart - (IPos)MAX_DIST(s) : NIL; |
---|
1281 | /* Stop when cur_match becomes <= limit. To simplify the code, |
---|
1282 | * we prevent matches with the string of window index 0. |
---|
1283 | */ |
---|
1284 | Posf *prev = s->prev; |
---|
1285 | uInt wmask = s->w_mask; |
---|
1286 | |
---|
1287 | #ifdef UNALIGNED_OK |
---|
1288 | /* Compare two bytes at a time. Note: this is not always beneficial. |
---|
1289 | * Try with and without -DUNALIGNED_OK to check. |
---|
1290 | */ |
---|
1291 | register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; |
---|
1292 | register ush scan_start = *(ushf*)scan; |
---|
1293 | register ush scan_end = *(ushf*)(scan+best_len-1); |
---|
1294 | #else |
---|
1295 | register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
---|
1296 | register Byte scan_end1 = scan[best_len-1]; |
---|
1297 | register Byte scan_end = scan[best_len]; |
---|
1298 | #endif |
---|
1299 | |
---|
1300 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
---|
1301 | * It is easy to get rid of this optimization if necessary. |
---|
1302 | */ |
---|
1303 | Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); |
---|
1304 | |
---|
1305 | /* Do not waste too much time if we already have a good match: */ |
---|
1306 | if (s->prev_length >= s->good_match) { |
---|
1307 | chain_length >>= 2; |
---|
1308 | } |
---|
1309 | /* Do not look for matches beyond the end of the input. This is necessary |
---|
1310 | * to make deflate deterministic. |
---|
1311 | */ |
---|
1312 | if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; |
---|
1313 | |
---|
1314 | Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); |
---|
1315 | |
---|
1316 | do { |
---|
1317 | Assert(cur_match < s->strstart, "no future"); |
---|
1318 | match = s->window + cur_match; |
---|
1319 | |
---|
1320 | /* Skip to next match if the match length cannot increase |
---|
1321 | * or if the match length is less than 2: |
---|
1322 | */ |
---|
1323 | #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) |
---|
1324 | /* This code assumes sizeof(unsigned short) == 2. Do not use |
---|
1325 | * UNALIGNED_OK if your compiler uses a different size. |
---|
1326 | */ |
---|
1327 | if (*(ushf*)(match+best_len-1) != scan_end || |
---|
1328 | *(ushf*)match != scan_start) continue; |
---|
1329 | |
---|
1330 | /* It is not necessary to compare scan[2] and match[2] since they are |
---|
1331 | * always equal when the other bytes match, given that the hash keys |
---|
1332 | * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at |
---|
1333 | * strstart+3, +5, ... up to strstart+257. We check for insufficient |
---|
1334 | * lookahead only every 4th comparison; the 128th check will be made |
---|
1335 | * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is |
---|
1336 | * necessary to put more guard bytes at the end of the window, or |
---|
1337 | * to check more often for insufficient lookahead. |
---|
1338 | */ |
---|
1339 | Assert(scan[2] == match[2], "scan[2]?"); |
---|
1340 | scan++, match++; |
---|
1341 | do { |
---|
1342 | } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
---|
1343 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
---|
1344 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
---|
1345 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
---|
1346 | scan < strend); |
---|
1347 | /* The funny "do {}" generates better code on most compilers */ |
---|
1348 | |
---|
1349 | /* Here, scan <= window+strstart+257 */ |
---|
1350 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
---|
1351 | if (*scan == *match) scan++; |
---|
1352 | |
---|
1353 | len = (MAX_MATCH - 1) - (int)(strend-scan); |
---|
1354 | scan = strend - (MAX_MATCH-1); |
---|
1355 | |
---|
1356 | #else /* UNALIGNED_OK */ |
---|
1357 | |
---|
1358 | if (match[best_len] != scan_end || |
---|
1359 | match[best_len-1] != scan_end1 || |
---|
1360 | *match != *scan || |
---|
1361 | *++match != scan[1]) continue; |
---|
1362 | |
---|
1363 | /* The check at best_len-1 can be removed because it will be made |
---|
1364 | * again later. (This heuristic is not always a win.) |
---|
1365 | * It is not necessary to compare scan[2] and match[2] since they |
---|
1366 | * are always equal when the other bytes match, given that |
---|
1367 | * the hash keys are equal and that HASH_BITS >= 8. |
---|
1368 | */ |
---|
1369 | scan += 2, match++; |
---|
1370 | Assert(*scan == *match, "match[2]?"); |
---|
1371 | |
---|
1372 | /* We check for insufficient lookahead only every 8th comparison; |
---|
1373 | * the 256th check will be made at strstart+258. |
---|
1374 | */ |
---|
1375 | do { |
---|
1376 | } while (*++scan == *++match && *++scan == *++match && |
---|
1377 | *++scan == *++match && *++scan == *++match && |
---|
1378 | *++scan == *++match && *++scan == *++match && |
---|
1379 | *++scan == *++match && *++scan == *++match && |
---|
1380 | scan < strend); |
---|
1381 | |
---|
1382 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
---|
1383 | |
---|
1384 | len = MAX_MATCH - (int)(strend - scan); |
---|
1385 | scan = strend - MAX_MATCH; |
---|
1386 | |
---|
1387 | #endif /* UNALIGNED_OK */ |
---|
1388 | |
---|
1389 | if (len > best_len) { |
---|
1390 | s->match_start = cur_match; |
---|
1391 | best_len = len; |
---|
1392 | if (len >= nice_match) break; |
---|
1393 | #ifdef UNALIGNED_OK |
---|
1394 | scan_end = *(ushf*)(scan+best_len-1); |
---|
1395 | #else |
---|
1396 | scan_end1 = scan[best_len-1]; |
---|
1397 | scan_end = scan[best_len]; |
---|
1398 | #endif |
---|
1399 | } |
---|
1400 | } while ((cur_match = prev[cur_match & wmask]) > limit |
---|
1401 | && --chain_length != 0); |
---|
1402 | |
---|
1403 | if ((uInt)best_len <= s->lookahead) return best_len; |
---|
1404 | return s->lookahead; |
---|
1405 | } |
---|
1406 | #endif /* ASMV */ |
---|
1407 | |
---|
1408 | #ifdef DEBUG_ZLIB |
---|
1409 | /* =========================================================================== |
---|
1410 | * Check that the match at match_start is indeed a match. |
---|
1411 | */ |
---|
1412 | local void check_match(s, start, match, length) |
---|
1413 | deflate_state *s; |
---|
1414 | IPos start, match; |
---|
1415 | int length; |
---|
1416 | { |
---|
1417 | /* check that the match is indeed a match */ |
---|
1418 | if (zmemcmp((charf *)s->window + match, |
---|
1419 | (charf *)s->window + start, length) != EQUAL) { |
---|
1420 | fprintf(stderr, " start %u, match %u, length %d\n", |
---|
1421 | start, match, length); |
---|
1422 | do { |
---|
1423 | fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); |
---|
1424 | } while (--length != 0); |
---|
1425 | z_error("invalid match"); |
---|
1426 | } |
---|
1427 | if (z_verbose > 1) { |
---|
1428 | fprintf(stderr,"\\[%d,%d]", start-match, length); |
---|
1429 | do { putc(s->window[start++], stderr); } while (--length != 0); |
---|
1430 | } |
---|
1431 | } |
---|
1432 | #else |
---|
1433 | # define check_match(s, start, match, length) |
---|
1434 | #endif |
---|
1435 | |
---|
1436 | /* =========================================================================== |
---|
1437 | * Fill the window when the lookahead becomes insufficient. |
---|
1438 | * Updates strstart and lookahead. |
---|
1439 | * |
---|
1440 | * IN assertion: lookahead < MIN_LOOKAHEAD |
---|
1441 | * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD |
---|
1442 | * At least one byte has been read, or avail_in == 0; reads are |
---|
1443 | * performed for at least two bytes (required for the zip translate_eol |
---|
1444 | * option -- not supported here). |
---|
1445 | */ |
---|
1446 | local void fill_window(s) |
---|
1447 | deflate_state *s; |
---|
1448 | { |
---|
1449 | register unsigned n, m; |
---|
1450 | register Posf *p; |
---|
1451 | unsigned more; /* Amount of free space at the end of the window. */ |
---|
1452 | uInt wsize = s->w_size; |
---|
1453 | |
---|
1454 | do { |
---|
1455 | more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); |
---|
1456 | |
---|
1457 | /* Deal with !@#$% 64K limit: */ |
---|
1458 | if (more == 0 && s->strstart == 0 && s->lookahead == 0) { |
---|
1459 | more = wsize; |
---|
1460 | |
---|
1461 | } else if (more == (unsigned)(-1)) { |
---|
1462 | /* Very unlikely, but possible on 16 bit machine if strstart == 0 |
---|
1463 | * and lookahead == 1 (input done one byte at time) |
---|
1464 | */ |
---|
1465 | more--; |
---|
1466 | |
---|
1467 | /* If the window is almost full and there is insufficient lookahead, |
---|
1468 | * move the upper half to the lower one to make room in the upper half. |
---|
1469 | */ |
---|
1470 | } else if (s->strstart >= wsize+MAX_DIST(s)) { |
---|
1471 | |
---|
1472 | zmemcpy((charf *)s->window, (charf *)s->window+wsize, |
---|
1473 | (unsigned)wsize); |
---|
1474 | s->match_start -= wsize; |
---|
1475 | s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ |
---|
1476 | s->block_start -= (long) wsize; |
---|
1477 | |
---|
1478 | /* Slide the hash table (could be avoided with 32 bit values |
---|
1479 | at the expense of memory usage). We slide even when level == 0 |
---|
1480 | to keep the hash table consistent if we switch back to level > 0 |
---|
1481 | later. (Using level 0 permanently is not an optimal usage of |
---|
1482 | zlib, so we don't care about this pathological case.) |
---|
1483 | */ |
---|
1484 | n = s->hash_size; |
---|
1485 | p = &s->head[n]; |
---|
1486 | do { |
---|
1487 | m = *--p; |
---|
1488 | *p = (Pos)(m >= wsize ? m-wsize : NIL); |
---|
1489 | } while (--n); |
---|
1490 | |
---|
1491 | n = wsize; |
---|
1492 | p = &s->prev[n]; |
---|
1493 | do { |
---|
1494 | m = *--p; |
---|
1495 | *p = (Pos)(m >= wsize ? m-wsize : NIL); |
---|
1496 | /* If n is not on any hash chain, prev[n] is garbage but |
---|
1497 | * its value will never be used. |
---|
1498 | */ |
---|
1499 | } while (--n); |
---|
1500 | more += wsize; |
---|
1501 | } |
---|
1502 | if (s->strm->avail_in == 0) return; |
---|
1503 | |
---|
1504 | /* If there was no sliding: |
---|
1505 | * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && |
---|
1506 | * more == window_size - lookahead - strstart |
---|
1507 | * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) |
---|
1508 | * => more >= window_size - 2*WSIZE + 2 |
---|
1509 | * In the BIG_MEM or MMAP case (not yet supported), |
---|
1510 | * window_size == input_size + MIN_LOOKAHEAD && |
---|
1511 | * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. |
---|
1512 | * Otherwise, window_size == 2*WSIZE so more >= 2. |
---|
1513 | * If there was sliding, more >= WSIZE. So in all cases, more >= 2. |
---|
1514 | */ |
---|
1515 | Assert(more >= 2, "more < 2"); |
---|
1516 | |
---|
1517 | n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, |
---|
1518 | more); |
---|
1519 | s->lookahead += n; |
---|
1520 | |
---|
1521 | /* Initialize the hash value now that we have some input: */ |
---|
1522 | if (s->lookahead >= MIN_MATCH) { |
---|
1523 | s->ins_h = s->window[s->strstart]; |
---|
1524 | UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
---|
1525 | #if MIN_MATCH != 3 |
---|
1526 | Call UPDATE_HASH() MIN_MATCH-3 more times |
---|
1527 | #endif |
---|
1528 | } |
---|
1529 | /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, |
---|
1530 | * but this is not important since only literal bytes will be emitted. |
---|
1531 | */ |
---|
1532 | |
---|
1533 | } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); |
---|
1534 | } |
---|
1535 | |
---|
1536 | /* =========================================================================== |
---|
1537 | * Flush the current block, with given end-of-file flag. |
---|
1538 | * IN assertion: strstart is set to the end of the current match. |
---|
1539 | */ |
---|
1540 | #define FLUSH_BLOCK_ONLY(s, eof) { \ |
---|
1541 | _tr_flush_block(s, (s->block_start >= 0L ? \ |
---|
1542 | (charf *)&s->window[(unsigned)s->block_start] : \ |
---|
1543 | (charf *)Z_NULL), \ |
---|
1544 | (ulg)((long)s->strstart - s->block_start), \ |
---|
1545 | (eof)); \ |
---|
1546 | s->block_start = s->strstart; \ |
---|
1547 | flush_pending(s->strm); \ |
---|
1548 | Tracev((stderr,"[FLUSH]")); \ |
---|
1549 | } |
---|
1550 | |
---|
1551 | /* Same but force premature exit if necessary. */ |
---|
1552 | #define FLUSH_BLOCK(s, eof) { \ |
---|
1553 | FLUSH_BLOCK_ONLY(s, eof); \ |
---|
1554 | if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ |
---|
1555 | } |
---|
1556 | |
---|
1557 | /* =========================================================================== |
---|
1558 | * Copy without compression as much as possible from the input stream, return |
---|
1559 | * the current block state. |
---|
1560 | * This function does not insert new strings in the dictionary since |
---|
1561 | * uncompressible data is probably not useful. This function is used |
---|
1562 | * only for the level=0 compression option. |
---|
1563 | * NOTE: this function should be optimized to avoid extra copying from |
---|
1564 | * window to pending_buf. |
---|
1565 | */ |
---|
1566 | local block_state deflate_stored(s, flush) |
---|
1567 | deflate_state *s; |
---|
1568 | int flush; |
---|
1569 | { |
---|
1570 | /* Stored blocks are limited to 0xffff bytes, pending_buf is limited |
---|
1571 | * to pending_buf_size, and each stored block has a 5 byte header: |
---|
1572 | */ |
---|
1573 | ulg max_block_size = 0xffff; |
---|
1574 | ulg max_start; |
---|
1575 | |
---|
1576 | if (max_block_size > s->pending_buf_size - 5) { |
---|
1577 | max_block_size = s->pending_buf_size - 5; |
---|
1578 | } |
---|
1579 | |
---|
1580 | /* Copy as much as possible from input to output: */ |
---|
1581 | for (;;) { |
---|
1582 | /* Fill the window as much as possible: */ |
---|
1583 | if (s->lookahead <= 1) { |
---|
1584 | |
---|
1585 | Assert(s->strstart < s->w_size+MAX_DIST(s) || |
---|
1586 | s->block_start >= (long)s->w_size, "slide too late"); |
---|
1587 | |
---|
1588 | fill_window(s); |
---|
1589 | if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; |
---|
1590 | |
---|
1591 | if (s->lookahead == 0) break; /* flush the current block */ |
---|
1592 | } |
---|
1593 | Assert(s->block_start >= 0L, "block gone"); |
---|
1594 | |
---|
1595 | s->strstart += s->lookahead; |
---|
1596 | s->lookahead = 0; |
---|
1597 | |
---|
1598 | /* Emit a stored block if pending_buf will be full: */ |
---|
1599 | max_start = s->block_start + max_block_size; |
---|
1600 | if (s->strstart == 0 || (ulg)s->strstart >= max_start) { |
---|
1601 | /* strstart == 0 is possible when wraparound on 16-bit machine */ |
---|
1602 | s->lookahead = (uInt)(s->strstart - max_start); |
---|
1603 | s->strstart = (uInt)max_start; |
---|
1604 | FLUSH_BLOCK(s, 0); |
---|
1605 | } |
---|
1606 | /* Flush if we may have to slide, otherwise block_start may become |
---|
1607 | * negative and the data will be gone: |
---|
1608 | */ |
---|
1609 | if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { |
---|
1610 | FLUSH_BLOCK(s, 0); |
---|
1611 | } |
---|
1612 | } |
---|
1613 | FLUSH_BLOCK(s, flush == Z_FINISH); |
---|
1614 | return flush == Z_FINISH ? finish_done : block_done; |
---|
1615 | } |
---|
1616 | |
---|
1617 | /* =========================================================================== |
---|
1618 | * Compress as much as possible from the input stream, return the current |
---|
1619 | * block state. |
---|
1620 | * This function does not perform lazy evaluation of matches and inserts |
---|
1621 | * new strings in the dictionary only for unmatched strings or for short |
---|
1622 | * matches. It is used only for the fast compression options. |
---|
1623 | */ |
---|
1624 | local block_state deflate_fast(s, flush) |
---|
1625 | deflate_state *s; |
---|
1626 | int flush; |
---|
1627 | { |
---|
1628 | IPos hash_head = NIL; /* head of the hash chain */ |
---|
1629 | int bflush; /* set if current block must be flushed */ |
---|
1630 | |
---|
1631 | for (;;) { |
---|
1632 | /* Make sure that we always have enough lookahead, except |
---|
1633 | * at the end of the input file. We need MAX_MATCH bytes |
---|
1634 | * for the next match, plus MIN_MATCH bytes to insert the |
---|
1635 | * string following the next match. |
---|
1636 | */ |
---|
1637 | if (s->lookahead < MIN_LOOKAHEAD) { |
---|
1638 | fill_window(s); |
---|
1639 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
---|
1640 | return need_more; |
---|
1641 | } |
---|
1642 | if (s->lookahead == 0) break; /* flush the current block */ |
---|
1643 | } |
---|
1644 | |
---|
1645 | /* Insert the string window[strstart .. strstart+2] in the |
---|
1646 | * dictionary, and set hash_head to the head of the hash chain: |
---|
1647 | */ |
---|
1648 | if (s->lookahead >= MIN_MATCH) { |
---|
1649 | INSERT_STRING(s, s->strstart, hash_head); |
---|
1650 | } |
---|
1651 | |
---|
1652 | /* Find the longest match, discarding those <= prev_length. |
---|
1653 | * At this point we have always match_length < MIN_MATCH |
---|
1654 | */ |
---|
1655 | if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { |
---|
1656 | /* To simplify the code, we prevent matches with the string |
---|
1657 | * of window index 0 (in particular we have to avoid a match |
---|
1658 | * of the string with itself at the start of the input file). |
---|
1659 | */ |
---|
1660 | if (s->strategy != Z_HUFFMAN_ONLY) { |
---|
1661 | s->match_length = longest_match (s, hash_head); |
---|
1662 | } |
---|
1663 | /* longest_match() sets match_start */ |
---|
1664 | } |
---|
1665 | if (s->match_length >= MIN_MATCH) { |
---|
1666 | check_match(s, s->strstart, s->match_start, s->match_length); |
---|
1667 | |
---|
1668 | bflush = _tr_tally(s, s->strstart - s->match_start, |
---|
1669 | s->match_length - MIN_MATCH); |
---|
1670 | |
---|
1671 | s->lookahead -= s->match_length; |
---|
1672 | |
---|
1673 | /* Insert new strings in the hash table only if the match length |
---|
1674 | * is not too large. This saves time but degrades compression. |
---|
1675 | */ |
---|
1676 | if (s->match_length <= s->max_insert_length && |
---|
1677 | s->lookahead >= MIN_MATCH) { |
---|
1678 | s->match_length--; /* string at strstart already in hash table */ |
---|
1679 | do { |
---|
1680 | s->strstart++; |
---|
1681 | INSERT_STRING(s, s->strstart, hash_head); |
---|
1682 | /* strstart never exceeds WSIZE-MAX_MATCH, so there are |
---|
1683 | * always MIN_MATCH bytes ahead. |
---|
1684 | */ |
---|
1685 | } while (--s->match_length != 0); |
---|
1686 | s->strstart++; |
---|
1687 | } else { |
---|
1688 | s->strstart += s->match_length; |
---|
1689 | s->match_length = 0; |
---|
1690 | s->ins_h = s->window[s->strstart]; |
---|
1691 | UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
---|
1692 | #if MIN_MATCH != 3 |
---|
1693 | Call UPDATE_HASH() MIN_MATCH-3 more times |
---|
1694 | #endif |
---|
1695 | /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not |
---|
1696 | * matter since it will be recomputed at next deflate call. |
---|
1697 | */ |
---|
1698 | } |
---|
1699 | } else { |
---|
1700 | /* No match, output a literal byte */ |
---|
1701 | Tracevv((stderr,"%c", s->window[s->strstart])); |
---|
1702 | bflush = _tr_tally (s, 0, s->window[s->strstart]); |
---|
1703 | s->lookahead--; |
---|
1704 | s->strstart++; |
---|
1705 | } |
---|
1706 | if (bflush) FLUSH_BLOCK(s, 0); |
---|
1707 | } |
---|
1708 | FLUSH_BLOCK(s, flush == Z_FINISH); |
---|
1709 | return flush == Z_FINISH ? finish_done : block_done; |
---|
1710 | } |
---|
1711 | |
---|
1712 | /* =========================================================================== |
---|
1713 | * Same as above, but achieves better compression. We use a lazy |
---|
1714 | * evaluation for matches: a match is finally adopted only if there is |
---|
1715 | * no better match at the next window position. |
---|
1716 | */ |
---|
1717 | local block_state deflate_slow(s, flush) |
---|
1718 | deflate_state *s; |
---|
1719 | int flush; |
---|
1720 | { |
---|
1721 | IPos hash_head = NIL; /* head of hash chain */ |
---|
1722 | int bflush; /* set if current block must be flushed */ |
---|
1723 | |
---|
1724 | /* Process the input block. */ |
---|
1725 | for (;;) { |
---|
1726 | /* Make sure that we always have enough lookahead, except |
---|
1727 | * at the end of the input file. We need MAX_MATCH bytes |
---|
1728 | * for the next match, plus MIN_MATCH bytes to insert the |
---|
1729 | * string following the next match. |
---|
1730 | */ |
---|
1731 | if (s->lookahead < MIN_LOOKAHEAD) { |
---|
1732 | fill_window(s); |
---|
1733 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
---|
1734 | return need_more; |
---|
1735 | } |
---|
1736 | if (s->lookahead == 0) break; /* flush the current block */ |
---|
1737 | } |
---|
1738 | |
---|
1739 | /* Insert the string window[strstart .. strstart+2] in the |
---|
1740 | * dictionary, and set hash_head to the head of the hash chain: |
---|
1741 | */ |
---|
1742 | if (s->lookahead >= MIN_MATCH) { |
---|
1743 | INSERT_STRING(s, s->strstart, hash_head); |
---|
1744 | } |
---|
1745 | |
---|
1746 | /* Find the longest match, discarding those <= prev_length. |
---|
1747 | */ |
---|
1748 | s->prev_length = s->match_length, s->prev_match = s->match_start; |
---|
1749 | s->match_length = MIN_MATCH-1; |
---|
1750 | |
---|
1751 | if (hash_head != NIL && s->prev_length < s->max_lazy_match && |
---|
1752 | s->strstart - hash_head <= MAX_DIST(s)) { |
---|
1753 | /* To simplify the code, we prevent matches with the string |
---|
1754 | * of window index 0 (in particular we have to avoid a match |
---|
1755 | * of the string with itself at the start of the input file). |
---|
1756 | */ |
---|
1757 | if (s->strategy != Z_HUFFMAN_ONLY) { |
---|
1758 | s->match_length = longest_match (s, hash_head); |
---|
1759 | } |
---|
1760 | /* longest_match() sets match_start */ |
---|
1761 | |
---|
1762 | if (s->match_length <= 5 && (s->strategy == Z_FILTERED || |
---|
1763 | (s->match_length == MIN_MATCH && |
---|
1764 | s->strstart - s->match_start > TOO_FAR))) { |
---|
1765 | |
---|
1766 | /* If prev_match is also MIN_MATCH, match_start is garbage |
---|
1767 | * but we will ignore the current match anyway. |
---|
1768 | */ |
---|
1769 | s->match_length = MIN_MATCH-1; |
---|
1770 | } |
---|
1771 | } |
---|
1772 | /* If there was a match at the previous step and the current |
---|
1773 | * match is not better, output the previous match: |
---|
1774 | */ |
---|
1775 | if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { |
---|
1776 | uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; |
---|
1777 | /* Do not insert strings in hash table beyond this. */ |
---|
1778 | |
---|
1779 | check_match(s, s->strstart-1, s->prev_match, s->prev_length); |
---|
1780 | |
---|
1781 | bflush = _tr_tally(s, s->strstart -1 - s->prev_match, |
---|
1782 | s->prev_length - MIN_MATCH); |
---|
1783 | |
---|
1784 | /* Insert in hash table all strings up to the end of the match. |
---|
1785 | * strstart-1 and strstart are already inserted. If there is not |
---|
1786 | * enough lookahead, the last two strings are not inserted in |
---|
1787 | * the hash table. |
---|
1788 | */ |
---|
1789 | s->lookahead -= s->prev_length-1; |
---|
1790 | s->prev_length -= 2; |
---|
1791 | do { |
---|
1792 | if (++s->strstart <= max_insert) { |
---|
1793 | INSERT_STRING(s, s->strstart, hash_head); |
---|
1794 | } |
---|
1795 | } while (--s->prev_length != 0); |
---|
1796 | s->match_available = 0; |
---|
1797 | s->match_length = MIN_MATCH-1; |
---|
1798 | s->strstart++; |
---|
1799 | |
---|
1800 | if (bflush) FLUSH_BLOCK(s, 0); |
---|
1801 | |
---|
1802 | } else if (s->match_available) { |
---|
1803 | /* If there was no match at the previous position, output a |
---|
1804 | * single literal. If there was a match but the current match |
---|
1805 | * is longer, truncate the previous match to a single literal. |
---|
1806 | */ |
---|
1807 | Tracevv((stderr,"%c", s->window[s->strstart-1])); |
---|
1808 | if (_tr_tally (s, 0, s->window[s->strstart-1])) { |
---|
1809 | FLUSH_BLOCK_ONLY(s, 0); |
---|
1810 | } |
---|
1811 | s->strstart++; |
---|
1812 | s->lookahead--; |
---|
1813 | if (s->strm->avail_out == 0) return need_more; |
---|
1814 | } else { |
---|
1815 | /* There is no previous match to compare with, wait for |
---|
1816 | * the next step to decide. |
---|
1817 | */ |
---|
1818 | s->match_available = 1; |
---|
1819 | s->strstart++; |
---|
1820 | s->lookahead--; |
---|
1821 | } |
---|
1822 | } |
---|
1823 | Assert (flush != Z_NO_FLUSH, "no flush?"); |
---|
1824 | if (s->match_available) { |
---|
1825 | Tracevv((stderr,"%c", s->window[s->strstart-1])); |
---|
1826 | _tr_tally (s, 0, s->window[s->strstart-1]); |
---|
1827 | s->match_available = 0; |
---|
1828 | } |
---|
1829 | FLUSH_BLOCK(s, flush == Z_FINISH); |
---|
1830 | return flush == Z_FINISH ? finish_done : block_done; |
---|
1831 | } |
---|
1832 | /* --- deflate.c */ |
---|
1833 | |
---|
1834 | /* +++ trees.c */ |
---|
1835 | /* trees.c -- output deflated data using Huffman coding |
---|
1836 | * Copyright (C) 1995-1996 Jean-loup Gailly |
---|
1837 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
1838 | */ |
---|
1839 | |
---|
1840 | /* |
---|
1841 | * ALGORITHM |
---|
1842 | * |
---|
1843 | * The "deflation" process uses several Huffman trees. The more |
---|
1844 | * common source values are represented by shorter bit sequences. |
---|
1845 | * |
---|
1846 | * Each code tree is stored in a compressed form which is itself |
---|
1847 | * a Huffman encoding of the lengths of all the code strings (in |
---|
1848 | * ascending order by source values). The actual code strings are |
---|
1849 | * reconstructed from the lengths in the inflate process, as described |
---|
1850 | * in the deflate specification. |
---|
1851 | * |
---|
1852 | * REFERENCES |
---|
1853 | * |
---|
1854 | * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". |
---|
1855 | * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc |
---|
1856 | * |
---|
1857 | * Storer, James A. |
---|
1858 | * Data Compression: Methods and Theory, pp. 49-50. |
---|
1859 | * Computer Science Press, 1988. ISBN 0-7167-8156-5. |
---|
1860 | * |
---|
1861 | * Sedgewick, R. |
---|
1862 | * Algorithms, p290. |
---|
1863 | * Addison-Wesley, 1983. ISBN 0-201-06672-6. |
---|
1864 | */ |
---|
1865 | |
---|
1866 | /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ |
---|
1867 | |
---|
1868 | /* #include "deflate.h" */ |
---|
1869 | |
---|
1870 | #ifdef DEBUG_ZLIB |
---|
1871 | # include <ctype.h> |
---|
1872 | #endif |
---|
1873 | |
---|
1874 | /* =========================================================================== |
---|
1875 | * Constants |
---|
1876 | */ |
---|
1877 | |
---|
1878 | #define MAX_BL_BITS 7 |
---|
1879 | /* Bit length codes must not exceed MAX_BL_BITS bits */ |
---|
1880 | |
---|
1881 | #define END_BLOCK 256 |
---|
1882 | /* end of block literal code */ |
---|
1883 | |
---|
1884 | #define REP_3_6 16 |
---|
1885 | /* repeat previous bit length 3-6 times (2 bits of repeat count) */ |
---|
1886 | |
---|
1887 | #define REPZ_3_10 17 |
---|
1888 | /* repeat a zero length 3-10 times (3 bits of repeat count) */ |
---|
1889 | |
---|
1890 | #define REPZ_11_138 18 |
---|
1891 | /* repeat a zero length 11-138 times (7 bits of repeat count) */ |
---|
1892 | |
---|
1893 | local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ |
---|
1894 | = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0}; |
---|
1895 | |
---|
1896 | local int extra_dbits[D_CODES] /* extra bits for each distance code */ |
---|
1897 | = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; |
---|
1898 | |
---|
1899 | local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ |
---|
1900 | = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; |
---|
1901 | |
---|
1902 | local uch bl_order[BL_CODES] |
---|
1903 | = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; |
---|
1904 | /* The lengths of the bit length codes are sent in order of decreasing |
---|
1905 | * probability, to avoid transmitting the lengths for unused bit length codes. |
---|
1906 | */ |
---|
1907 | |
---|
1908 | #define Buf_size (8 * 2*sizeof(char)) |
---|
1909 | /* Number of bits used within bi_buf. (bi_buf might be implemented on |
---|
1910 | * more than 16 bits on some systems.) |
---|
1911 | */ |
---|
1912 | |
---|
1913 | /* =========================================================================== |
---|
1914 | * Local data. These are initialized only once. |
---|
1915 | */ |
---|
1916 | |
---|
1917 | local ct_data static_ltree[L_CODES+2]; |
---|
1918 | /* The static literal tree. Since the bit lengths are imposed, there is no |
---|
1919 | * need for the L_CODES extra codes used during heap construction. However |
---|
1920 | * The codes 286 and 287 are needed to build a canonical tree (see _tr_init |
---|
1921 | * below). |
---|
1922 | */ |
---|
1923 | |
---|
1924 | local ct_data static_dtree[D_CODES]; |
---|
1925 | /* The static distance tree. (Actually a trivial tree since all codes use |
---|
1926 | * 5 bits.) |
---|
1927 | */ |
---|
1928 | |
---|
1929 | local uch dist_code[512]; |
---|
1930 | /* distance codes. The first 256 values correspond to the distances |
---|
1931 | * 3 .. 258, the last 256 values correspond to the top 8 bits of |
---|
1932 | * the 15 bit distances. |
---|
1933 | */ |
---|
1934 | |
---|
1935 | local uch length_code[MAX_MATCH-MIN_MATCH+1]; |
---|
1936 | /* length code for each normalized match length (0 == MIN_MATCH) */ |
---|
1937 | |
---|
1938 | local int base_length[LENGTH_CODES]; |
---|
1939 | /* First normalized length for each code (0 = MIN_MATCH) */ |
---|
1940 | |
---|
1941 | local int base_dist[D_CODES]; |
---|
1942 | /* First normalized distance for each code (0 = distance of 1) */ |
---|
1943 | |
---|
1944 | struct static_tree_desc_s { |
---|
1945 | ct_data *static_tree; /* static tree or NULL */ |
---|
1946 | intf *extra_bits; /* extra bits for each code or NULL */ |
---|
1947 | int extra_base; /* base index for extra_bits */ |
---|
1948 | int elems; /* max number of elements in the tree */ |
---|
1949 | int max_length; /* max bit length for the codes */ |
---|
1950 | }; |
---|
1951 | |
---|
1952 | local static_tree_desc static_l_desc = |
---|
1953 | {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; |
---|
1954 | |
---|
1955 | local static_tree_desc static_d_desc = |
---|
1956 | {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; |
---|
1957 | |
---|
1958 | local static_tree_desc static_bl_desc = |
---|
1959 | {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; |
---|
1960 | |
---|
1961 | /* =========================================================================== |
---|
1962 | * Local (static) routines in this file. |
---|
1963 | */ |
---|
1964 | |
---|
1965 | local void tr_static_init OF((void)); |
---|
1966 | local void init_block OF((deflate_state *s)); |
---|
1967 | local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); |
---|
1968 | local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); |
---|
1969 | local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); |
---|
1970 | local void build_tree OF((deflate_state *s, tree_desc *desc)); |
---|
1971 | local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); |
---|
1972 | local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); |
---|
1973 | local int build_bl_tree OF((deflate_state *s)); |
---|
1974 | local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, |
---|
1975 | int blcodes)); |
---|
1976 | local void compress_block OF((deflate_state *s, ct_data *ltree, |
---|
1977 | ct_data *dtree)); |
---|
1978 | local void set_data_type OF((deflate_state *s)); |
---|
1979 | local unsigned bi_reverse OF((unsigned value, int length)); |
---|
1980 | local void bi_windup OF((deflate_state *s)); |
---|
1981 | local void bi_flush OF((deflate_state *s)); |
---|
1982 | local void copy_block OF((deflate_state *s, charf *buf, unsigned len, |
---|
1983 | int header)); |
---|
1984 | |
---|
1985 | #ifndef DEBUG_ZLIB |
---|
1986 | # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) |
---|
1987 | /* Send a code of the given tree. c and tree must not have side effects */ |
---|
1988 | |
---|
1989 | #else /* DEBUG_ZLIB */ |
---|
1990 | # define send_code(s, c, tree) \ |
---|
1991 | { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ |
---|
1992 | send_bits(s, tree[c].Code, tree[c].Len); } |
---|
1993 | #endif |
---|
1994 | |
---|
1995 | #define d_code(dist) \ |
---|
1996 | ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) |
---|
1997 | /* Mapping from a distance to a distance code. dist is the distance - 1 and |
---|
1998 | * must not have side effects. dist_code[256] and dist_code[257] are never |
---|
1999 | * used. |
---|
2000 | */ |
---|
2001 | |
---|
2002 | /* =========================================================================== |
---|
2003 | * Output a short LSB first on the stream. |
---|
2004 | * IN assertion: there is enough room in pendingBuf. |
---|
2005 | */ |
---|
2006 | #define put_short(s, w) { \ |
---|
2007 | put_byte(s, (uch)((w) & 0xff)); \ |
---|
2008 | put_byte(s, (uch)((ush)(w) >> 8)); \ |
---|
2009 | } |
---|
2010 | |
---|
2011 | /* =========================================================================== |
---|
2012 | * Send a value on a given number of bits. |
---|
2013 | * IN assertion: length <= 16 and value fits in length bits. |
---|
2014 | */ |
---|
2015 | #ifdef DEBUG_ZLIB |
---|
2016 | local void send_bits OF((deflate_state *s, int value, int length)); |
---|
2017 | |
---|
2018 | local void send_bits(s, value, length) |
---|
2019 | deflate_state *s; |
---|
2020 | int value; /* value to send */ |
---|
2021 | int length; /* number of bits */ |
---|
2022 | { |
---|
2023 | Tracevv((stderr," l %2d v %4x ", length, value)); |
---|
2024 | Assert(length > 0 && length <= 15, "invalid length"); |
---|
2025 | s->bits_sent += (ulg)length; |
---|
2026 | |
---|
2027 | /* If not enough room in bi_buf, use (valid) bits from bi_buf and |
---|
2028 | * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) |
---|
2029 | * unused bits in value. |
---|
2030 | */ |
---|
2031 | if (s->bi_valid > (int)Buf_size - length) { |
---|
2032 | s->bi_buf |= (value << s->bi_valid); |
---|
2033 | put_short(s, s->bi_buf); |
---|
2034 | s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); |
---|
2035 | s->bi_valid += length - Buf_size; |
---|
2036 | } else { |
---|
2037 | s->bi_buf |= value << s->bi_valid; |
---|
2038 | s->bi_valid += length; |
---|
2039 | } |
---|
2040 | } |
---|
2041 | #else /* !DEBUG_ZLIB */ |
---|
2042 | |
---|
2043 | #define send_bits(s, value, length) \ |
---|
2044 | { int len = length;\ |
---|
2045 | if (s->bi_valid > (int)Buf_size - len) {\ |
---|
2046 | int val = value;\ |
---|
2047 | s->bi_buf |= (val << s->bi_valid);\ |
---|
2048 | put_short(s, s->bi_buf);\ |
---|
2049 | s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ |
---|
2050 | s->bi_valid += len - Buf_size;\ |
---|
2051 | } else {\ |
---|
2052 | s->bi_buf |= (value) << s->bi_valid;\ |
---|
2053 | s->bi_valid += len;\ |
---|
2054 | }\ |
---|
2055 | } |
---|
2056 | #endif /* DEBUG_ZLIB */ |
---|
2057 | |
---|
2058 | |
---|
2059 | #define MAX(a,b) (a >= b ? a : b) |
---|
2060 | /* the arguments must not have side effects */ |
---|
2061 | |
---|
2062 | /* =========================================================================== |
---|
2063 | * Initialize the various 'constant' tables. In a multi-threaded environment, |
---|
2064 | * this function may be called by two threads concurrently, but this is |
---|
2065 | * harmless since both invocations do exactly the same thing. |
---|
2066 | */ |
---|
2067 | local void tr_static_init() |
---|
2068 | { |
---|
2069 | static int static_init_done = 0; |
---|
2070 | int n; /* iterates over tree elements */ |
---|
2071 | int bits; /* bit counter */ |
---|
2072 | int length; /* length value */ |
---|
2073 | int code; /* code value */ |
---|
2074 | int dist; /* distance index */ |
---|
2075 | ush bl_count[MAX_BITS+1]; |
---|
2076 | /* number of codes at each bit length for an optimal tree */ |
---|
2077 | |
---|
2078 | if (static_init_done) return; |
---|
2079 | |
---|
2080 | /* Initialize the mapping length (0..255) -> length code (0..28) */ |
---|
2081 | length = 0; |
---|
2082 | for (code = 0; code < LENGTH_CODES-1; code++) { |
---|
2083 | base_length[code] = length; |
---|
2084 | for (n = 0; n < (1<<extra_lbits[code]); n++) { |
---|
2085 | length_code[length++] = (uch)code; |
---|
2086 | } |
---|
2087 | } |
---|
2088 | Assert (length == 256, "tr_static_init: length != 256"); |
---|
2089 | /* Note that the length 255 (match length 258) can be represented |
---|
2090 | * in two different ways: code 284 + 5 bits or code 285, so we |
---|
2091 | * overwrite length_code[255] to use the best encoding: |
---|
2092 | */ |
---|
2093 | length_code[length-1] = (uch)code; |
---|
2094 | |
---|
2095 | /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ |
---|
2096 | dist = 0; |
---|
2097 | for (code = 0 ; code < 16; code++) { |
---|
2098 | base_dist[code] = dist; |
---|
2099 | for (n = 0; n < (1<<extra_dbits[code]); n++) { |
---|
2100 | dist_code[dist++] = (uch)code; |
---|
2101 | } |
---|
2102 | } |
---|
2103 | Assert (dist == 256, "tr_static_init: dist != 256"); |
---|
2104 | dist >>= 7; /* from now on, all distances are divided by 128 */ |
---|
2105 | for ( ; code < D_CODES; code++) { |
---|
2106 | base_dist[code] = dist << 7; |
---|
2107 | for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { |
---|
2108 | dist_code[256 + dist++] = (uch)code; |
---|
2109 | } |
---|
2110 | } |
---|
2111 | Assert (dist == 256, "tr_static_init: 256+dist != 512"); |
---|
2112 | |
---|
2113 | /* Construct the codes of the static literal tree */ |
---|
2114 | for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; |
---|
2115 | n = 0; |
---|
2116 | while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; |
---|
2117 | while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; |
---|
2118 | while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; |
---|
2119 | while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; |
---|
2120 | /* Codes 286 and 287 do not exist, but we must include them in the |
---|
2121 | * tree construction to get a canonical Huffman tree (longest code |
---|
2122 | * all ones) |
---|
2123 | */ |
---|
2124 | gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); |
---|
2125 | |
---|
2126 | /* The static distance tree is trivial: */ |
---|
2127 | for (n = 0; n < D_CODES; n++) { |
---|
2128 | static_dtree[n].Len = 5; |
---|
2129 | static_dtree[n].Code = bi_reverse((unsigned)n, 5); |
---|
2130 | } |
---|
2131 | static_init_done = 1; |
---|
2132 | } |
---|
2133 | |
---|
2134 | /* =========================================================================== |
---|
2135 | * Initialize the tree data structures for a new zlib stream. |
---|
2136 | */ |
---|
2137 | void _tr_init(s) |
---|
2138 | deflate_state *s; |
---|
2139 | { |
---|
2140 | tr_static_init(); |
---|
2141 | |
---|
2142 | s->compressed_len = 0L; |
---|
2143 | |
---|
2144 | s->l_desc.dyn_tree = s->dyn_ltree; |
---|
2145 | s->l_desc.stat_desc = &static_l_desc; |
---|
2146 | |
---|
2147 | s->d_desc.dyn_tree = s->dyn_dtree; |
---|
2148 | s->d_desc.stat_desc = &static_d_desc; |
---|
2149 | |
---|
2150 | s->bl_desc.dyn_tree = s->bl_tree; |
---|
2151 | s->bl_desc.stat_desc = &static_bl_desc; |
---|
2152 | |
---|
2153 | s->bi_buf = 0; |
---|
2154 | s->bi_valid = 0; |
---|
2155 | s->last_eob_len = 8; /* enough lookahead for inflate */ |
---|
2156 | #ifdef DEBUG_ZLIB |
---|
2157 | s->bits_sent = 0L; |
---|
2158 | #endif |
---|
2159 | |
---|
2160 | /* Initialize the first block of the first file: */ |
---|
2161 | init_block(s); |
---|
2162 | } |
---|
2163 | |
---|
2164 | /* =========================================================================== |
---|
2165 | * Initialize a new block. |
---|
2166 | */ |
---|
2167 | local void init_block(s) |
---|
2168 | deflate_state *s; |
---|
2169 | { |
---|
2170 | int n; /* iterates over tree elements */ |
---|
2171 | |
---|
2172 | /* Initialize the trees. */ |
---|
2173 | for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; |
---|
2174 | for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; |
---|
2175 | for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; |
---|
2176 | |
---|
2177 | s->dyn_ltree[END_BLOCK].Freq = 1; |
---|
2178 | s->opt_len = s->static_len = 0L; |
---|
2179 | s->last_lit = s->matches = 0; |
---|
2180 | } |
---|
2181 | |
---|
2182 | #define SMALLEST 1 |
---|
2183 | /* Index within the heap array of least frequent node in the Huffman tree */ |
---|
2184 | |
---|
2185 | |
---|
2186 | /* =========================================================================== |
---|
2187 | * Remove the smallest element from the heap and recreate the heap with |
---|
2188 | * one less element. Updates heap and heap_len. |
---|
2189 | */ |
---|
2190 | #define pqremove(s, tree, top) \ |
---|
2191 | {\ |
---|
2192 | top = s->heap[SMALLEST]; \ |
---|
2193 | s->heap[SMALLEST] = s->heap[s->heap_len--]; \ |
---|
2194 | pqdownheap(s, tree, SMALLEST); \ |
---|
2195 | } |
---|
2196 | |
---|
2197 | /* =========================================================================== |
---|
2198 | * Compares to subtrees, using the tree depth as tie breaker when |
---|
2199 | * the subtrees have equal frequency. This minimizes the worst case length. |
---|
2200 | */ |
---|
2201 | #define smaller(tree, n, m, depth) \ |
---|
2202 | (tree[n].Freq < tree[m].Freq || \ |
---|
2203 | (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) |
---|
2204 | |
---|
2205 | /* =========================================================================== |
---|
2206 | * Restore the heap property by moving down the tree starting at node k, |
---|
2207 | * exchanging a node with the smallest of its two sons if necessary, stopping |
---|
2208 | * when the heap property is re-established (each father smaller than its |
---|
2209 | * two sons). |
---|
2210 | */ |
---|
2211 | local void pqdownheap(s, tree, k) |
---|
2212 | deflate_state *s; |
---|
2213 | ct_data *tree; /* the tree to restore */ |
---|
2214 | int k; /* node to move down */ |
---|
2215 | { |
---|
2216 | int v = s->heap[k]; |
---|
2217 | int j = k << 1; /* left son of k */ |
---|
2218 | while (j <= s->heap_len) { |
---|
2219 | /* Set j to the smallest of the two sons: */ |
---|
2220 | if (j < s->heap_len && |
---|
2221 | smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { |
---|
2222 | j++; |
---|
2223 | } |
---|
2224 | /* Exit if v is smaller than both sons */ |
---|
2225 | if (smaller(tree, v, s->heap[j], s->depth)) break; |
---|
2226 | |
---|
2227 | /* Exchange v with the smallest son */ |
---|
2228 | s->heap[k] = s->heap[j]; k = j; |
---|
2229 | |
---|
2230 | /* And continue down the tree, setting j to the left son of k */ |
---|
2231 | j <<= 1; |
---|
2232 | } |
---|
2233 | s->heap[k] = v; |
---|
2234 | } |
---|
2235 | |
---|
2236 | /* =========================================================================== |
---|
2237 | * Compute the optimal bit lengths for a tree and update the total bit length |
---|
2238 | * for the current block. |
---|
2239 | * IN assertion: the fields freq and dad are set, heap[heap_max] and |
---|
2240 | * above are the tree nodes sorted by increasing frequency. |
---|
2241 | * OUT assertions: the field len is set to the optimal bit length, the |
---|
2242 | * array bl_count contains the frequencies for each bit length. |
---|
2243 | * The length opt_len is updated; static_len is also updated if stree is |
---|
2244 | * not null. |
---|
2245 | */ |
---|
2246 | local void gen_bitlen(s, desc) |
---|
2247 | deflate_state *s; |
---|
2248 | tree_desc *desc; /* the tree descriptor */ |
---|
2249 | { |
---|
2250 | ct_data *tree = desc->dyn_tree; |
---|
2251 | int max_code = desc->max_code; |
---|
2252 | ct_data *stree = desc->stat_desc->static_tree; |
---|
2253 | intf *extra = desc->stat_desc->extra_bits; |
---|
2254 | int base = desc->stat_desc->extra_base; |
---|
2255 | int max_length = desc->stat_desc->max_length; |
---|
2256 | int h; /* heap index */ |
---|
2257 | int n, m; /* iterate over the tree elements */ |
---|
2258 | int bits; /* bit length */ |
---|
2259 | int xbits; /* extra bits */ |
---|
2260 | ush f; /* frequency */ |
---|
2261 | int overflow = 0; /* number of elements with bit length too large */ |
---|
2262 | |
---|
2263 | for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; |
---|
2264 | |
---|
2265 | /* In a first pass, compute the optimal bit lengths (which may |
---|
2266 | * overflow in the case of the bit length tree). |
---|
2267 | */ |
---|
2268 | tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ |
---|
2269 | |
---|
2270 | for (h = s->heap_max+1; h < HEAP_SIZE; h++) { |
---|
2271 | n = s->heap[h]; |
---|
2272 | bits = tree[tree[n].Dad].Len + 1; |
---|
2273 | if (bits > max_length) bits = max_length, overflow++; |
---|
2274 | tree[n].Len = (ush)bits; |
---|
2275 | /* We overwrite tree[n].Dad which is no longer needed */ |
---|
2276 | |
---|
2277 | if (n > max_code) continue; /* not a leaf node */ |
---|
2278 | |
---|
2279 | s->bl_count[bits]++; |
---|
2280 | xbits = 0; |
---|
2281 | if (n >= base) xbits = extra[n-base]; |
---|
2282 | f = tree[n].Freq; |
---|
2283 | s->opt_len += (ulg)f * (bits + xbits); |
---|
2284 | if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); |
---|
2285 | } |
---|
2286 | if (overflow == 0) return; |
---|
2287 | |
---|
2288 | Trace((stderr,"\nbit length overflow\n")); |
---|
2289 | /* This happens for example on obj2 and pic of the Calgary corpus */ |
---|
2290 | |
---|
2291 | /* Find the first bit length which could increase: */ |
---|
2292 | do { |
---|
2293 | bits = max_length-1; |
---|
2294 | while (s->bl_count[bits] == 0) bits--; |
---|
2295 | s->bl_count[bits]--; /* move one leaf down the tree */ |
---|
2296 | s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ |
---|
2297 | s->bl_count[max_length]--; |
---|
2298 | /* The brother of the overflow item also moves one step up, |
---|
2299 | * but this does not affect bl_count[max_length] |
---|
2300 | */ |
---|
2301 | overflow -= 2; |
---|
2302 | } while (overflow > 0); |
---|
2303 | |
---|
2304 | /* Now recompute all bit lengths, scanning in increasing frequency. |
---|
2305 | * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all |
---|
2306 | * lengths instead of fixing only the wrong ones. This idea is taken |
---|
2307 | * from 'ar' written by Haruhiko Okumura.) |
---|
2308 | */ |
---|
2309 | for (bits = max_length; bits != 0; bits--) { |
---|
2310 | n = s->bl_count[bits]; |
---|
2311 | while (n != 0) { |
---|
2312 | m = s->heap[--h]; |
---|
2313 | if (m > max_code) continue; |
---|
2314 | if (tree[m].Len != (unsigned) bits) { |
---|
2315 | Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); |
---|
2316 | s->opt_len += ((long)bits - (long)tree[m].Len) |
---|
2317 | *(long)tree[m].Freq; |
---|
2318 | tree[m].Len = (ush)bits; |
---|
2319 | } |
---|
2320 | n--; |
---|
2321 | } |
---|
2322 | } |
---|
2323 | } |
---|
2324 | |
---|
2325 | /* =========================================================================== |
---|
2326 | * Generate the codes for a given tree and bit counts (which need not be |
---|
2327 | * optimal). |
---|
2328 | * IN assertion: the array bl_count contains the bit length statistics for |
---|
2329 | * the given tree and the field len is set for all tree elements. |
---|
2330 | * OUT assertion: the field code is set for all tree elements of non |
---|
2331 | * zero code length. |
---|
2332 | */ |
---|
2333 | local void gen_codes (tree, max_code, bl_count) |
---|
2334 | ct_data *tree; /* the tree to decorate */ |
---|
2335 | int max_code; /* largest code with non zero frequency */ |
---|
2336 | ushf *bl_count; /* number of codes at each bit length */ |
---|
2337 | { |
---|
2338 | ush next_code[MAX_BITS+1]; /* next code value for each bit length */ |
---|
2339 | ush code = 0; /* running code value */ |
---|
2340 | int bits; /* bit index */ |
---|
2341 | int n; /* code index */ |
---|
2342 | |
---|
2343 | /* The distribution counts are first used to generate the code values |
---|
2344 | * without bit reversal. |
---|
2345 | */ |
---|
2346 | for (bits = 1; bits <= MAX_BITS; bits++) { |
---|
2347 | next_code[bits] = code = (code + bl_count[bits-1]) << 1; |
---|
2348 | } |
---|
2349 | /* Check that the bit counts in bl_count are consistent. The last code |
---|
2350 | * must be all ones. |
---|
2351 | */ |
---|
2352 | Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, |
---|
2353 | "inconsistent bit counts"); |
---|
2354 | Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); |
---|
2355 | |
---|
2356 | for (n = 0; n <= max_code; n++) { |
---|
2357 | int len = tree[n].Len; |
---|
2358 | if (len == 0) continue; |
---|
2359 | /* Now reverse the bits */ |
---|
2360 | tree[n].Code = bi_reverse(next_code[len]++, len); |
---|
2361 | |
---|
2362 | Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", |
---|
2363 | n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); |
---|
2364 | } |
---|
2365 | } |
---|
2366 | |
---|
2367 | /* =========================================================================== |
---|
2368 | * Construct one Huffman tree and assigns the code bit strings and lengths. |
---|
2369 | * Update the total bit length for the current block. |
---|
2370 | * IN assertion: the field freq is set for all tree elements. |
---|
2371 | * OUT assertions: the fields len and code are set to the optimal bit length |
---|
2372 | * and corresponding code. The length opt_len is updated; static_len is |
---|
2373 | * also updated if stree is not null. The field max_code is set. |
---|
2374 | */ |
---|
2375 | local void build_tree(s, desc) |
---|
2376 | deflate_state *s; |
---|
2377 | tree_desc *desc; /* the tree descriptor */ |
---|
2378 | { |
---|
2379 | ct_data *tree = desc->dyn_tree; |
---|
2380 | ct_data *stree = desc->stat_desc->static_tree; |
---|
2381 | int elems = desc->stat_desc->elems; |
---|
2382 | int n, m; /* iterate over heap elements */ |
---|
2383 | int max_code = -1; /* largest code with non zero frequency */ |
---|
2384 | int node; /* new node being created */ |
---|
2385 | |
---|
2386 | /* Construct the initial heap, with least frequent element in |
---|
2387 | * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. |
---|
2388 | * heap[0] is not used. |
---|
2389 | */ |
---|
2390 | s->heap_len = 0, s->heap_max = HEAP_SIZE; |
---|
2391 | |
---|
2392 | for (n = 0; n < elems; n++) { |
---|
2393 | if (tree[n].Freq != 0) { |
---|
2394 | s->heap[++(s->heap_len)] = max_code = n; |
---|
2395 | s->depth[n] = 0; |
---|
2396 | } else { |
---|
2397 | tree[n].Len = 0; |
---|
2398 | } |
---|
2399 | } |
---|
2400 | |
---|
2401 | /* The pkzip format requires that at least one distance code exists, |
---|
2402 | * and that at least one bit should be sent even if there is only one |
---|
2403 | * possible code. So to avoid special checks later on we force at least |
---|
2404 | * two codes of non zero frequency. |
---|
2405 | */ |
---|
2406 | while (s->heap_len < 2) { |
---|
2407 | node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); |
---|
2408 | tree[node].Freq = 1; |
---|
2409 | s->depth[node] = 0; |
---|
2410 | s->opt_len--; if (stree) s->static_len -= stree[node].Len; |
---|
2411 | /* node is 0 or 1 so it does not have extra bits */ |
---|
2412 | } |
---|
2413 | desc->max_code = max_code; |
---|
2414 | |
---|
2415 | /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, |
---|
2416 | * establish sub-heaps of increasing lengths: |
---|
2417 | */ |
---|
2418 | for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); |
---|
2419 | |
---|
2420 | /* Construct the Huffman tree by repeatedly combining the least two |
---|
2421 | * frequent nodes. |
---|
2422 | */ |
---|
2423 | node = elems; /* next internal node of the tree */ |
---|
2424 | do { |
---|
2425 | pqremove(s, tree, n); /* n = node of least frequency */ |
---|
2426 | m = s->heap[SMALLEST]; /* m = node of next least frequency */ |
---|
2427 | |
---|
2428 | s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ |
---|
2429 | s->heap[--(s->heap_max)] = m; |
---|
2430 | |
---|
2431 | /* Create a new node father of n and m */ |
---|
2432 | tree[node].Freq = tree[n].Freq + tree[m].Freq; |
---|
2433 | s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); |
---|
2434 | tree[n].Dad = tree[m].Dad = (ush)node; |
---|
2435 | #ifdef DUMP_BL_TREE |
---|
2436 | if (tree == s->bl_tree) { |
---|
2437 | fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", |
---|
2438 | node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); |
---|
2439 | } |
---|
2440 | #endif |
---|
2441 | /* and insert the new node in the heap */ |
---|
2442 | s->heap[SMALLEST] = node++; |
---|
2443 | pqdownheap(s, tree, SMALLEST); |
---|
2444 | |
---|
2445 | } while (s->heap_len >= 2); |
---|
2446 | |
---|
2447 | s->heap[--(s->heap_max)] = s->heap[SMALLEST]; |
---|
2448 | |
---|
2449 | /* At this point, the fields freq and dad are set. We can now |
---|
2450 | * generate the bit lengths. |
---|
2451 | */ |
---|
2452 | gen_bitlen(s, (tree_desc *)desc); |
---|
2453 | |
---|
2454 | /* The field len is now set, we can generate the bit codes */ |
---|
2455 | gen_codes ((ct_data *)tree, max_code, s->bl_count); |
---|
2456 | } |
---|
2457 | |
---|
2458 | /* =========================================================================== |
---|
2459 | * Scan a literal or distance tree to determine the frequencies of the codes |
---|
2460 | * in the bit length tree. |
---|
2461 | */ |
---|
2462 | local void scan_tree (s, tree, max_code) |
---|
2463 | deflate_state *s; |
---|
2464 | ct_data *tree; /* the tree to be scanned */ |
---|
2465 | int max_code; /* and its largest code of non zero frequency */ |
---|
2466 | { |
---|
2467 | int n; /* iterates over all tree elements */ |
---|
2468 | int prevlen = -1; /* last emitted length */ |
---|
2469 | int curlen; /* length of current code */ |
---|
2470 | int nextlen = tree[0].Len; /* length of next code */ |
---|
2471 | int count = 0; /* repeat count of the current code */ |
---|
2472 | int max_count = 7; /* max repeat count */ |
---|
2473 | int min_count = 4; /* min repeat count */ |
---|
2474 | |
---|
2475 | if (nextlen == 0) max_count = 138, min_count = 3; |
---|
2476 | tree[max_code+1].Len = (ush)0xffff; /* guard */ |
---|
2477 | |
---|
2478 | for (n = 0; n <= max_code; n++) { |
---|
2479 | curlen = nextlen; nextlen = tree[n+1].Len; |
---|
2480 | if (++count < max_count && curlen == nextlen) { |
---|
2481 | continue; |
---|
2482 | } else if (count < min_count) { |
---|
2483 | s->bl_tree[curlen].Freq += count; |
---|
2484 | } else if (curlen != 0) { |
---|
2485 | if (curlen != prevlen) s->bl_tree[curlen].Freq++; |
---|
2486 | s->bl_tree[REP_3_6].Freq++; |
---|
2487 | } else if (count <= 10) { |
---|
2488 | s->bl_tree[REPZ_3_10].Freq++; |
---|
2489 | } else { |
---|
2490 | s->bl_tree[REPZ_11_138].Freq++; |
---|
2491 | } |
---|
2492 | count = 0; prevlen = curlen; |
---|
2493 | if (nextlen == 0) { |
---|
2494 | max_count = 138, min_count = 3; |
---|
2495 | } else if (curlen == nextlen) { |
---|
2496 | max_count = 6, min_count = 3; |
---|
2497 | } else { |
---|
2498 | max_count = 7, min_count = 4; |
---|
2499 | } |
---|
2500 | } |
---|
2501 | } |
---|
2502 | |
---|
2503 | /* =========================================================================== |
---|
2504 | * Send a literal or distance tree in compressed form, using the codes in |
---|
2505 | * bl_tree. |
---|
2506 | */ |
---|
2507 | local void send_tree (s, tree, max_code) |
---|
2508 | deflate_state *s; |
---|
2509 | ct_data *tree; /* the tree to be scanned */ |
---|
2510 | int max_code; /* and its largest code of non zero frequency */ |
---|
2511 | { |
---|
2512 | int n; /* iterates over all tree elements */ |
---|
2513 | int prevlen = -1; /* last emitted length */ |
---|
2514 | int curlen; /* length of current code */ |
---|
2515 | int nextlen = tree[0].Len; /* length of next code */ |
---|
2516 | int count = 0; /* repeat count of the current code */ |
---|
2517 | int max_count = 7; /* max repeat count */ |
---|
2518 | int min_count = 4; /* min repeat count */ |
---|
2519 | |
---|
2520 | /* tree[max_code+1].Len = -1; */ /* guard already set */ |
---|
2521 | if (nextlen == 0) max_count = 138, min_count = 3; |
---|
2522 | |
---|
2523 | for (n = 0; n <= max_code; n++) { |
---|
2524 | curlen = nextlen; nextlen = tree[n+1].Len; |
---|
2525 | if (++count < max_count && curlen == nextlen) { |
---|
2526 | continue; |
---|
2527 | } else if (count < min_count) { |
---|
2528 | do { send_code(s, curlen, s->bl_tree); } while (--count != 0); |
---|
2529 | |
---|
2530 | } else if (curlen != 0) { |
---|
2531 | if (curlen != prevlen) { |
---|
2532 | send_code(s, curlen, s->bl_tree); count--; |
---|
2533 | } |
---|
2534 | Assert(count >= 3 && count <= 6, " 3_6?"); |
---|
2535 | send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); |
---|
2536 | |
---|
2537 | } else if (count <= 10) { |
---|
2538 | send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); |
---|
2539 | |
---|
2540 | } else { |
---|
2541 | send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); |
---|
2542 | } |
---|
2543 | count = 0; prevlen = curlen; |
---|
2544 | if (nextlen == 0) { |
---|
2545 | max_count = 138, min_count = 3; |
---|
2546 | } else if (curlen == nextlen) { |
---|
2547 | max_count = 6, min_count = 3; |
---|
2548 | } else { |
---|
2549 | max_count = 7, min_count = 4; |
---|
2550 | } |
---|
2551 | } |
---|
2552 | } |
---|
2553 | |
---|
2554 | /* =========================================================================== |
---|
2555 | * Construct the Huffman tree for the bit lengths and return the index in |
---|
2556 | * bl_order of the last bit length code to send. |
---|
2557 | */ |
---|
2558 | local int build_bl_tree(s) |
---|
2559 | deflate_state *s; |
---|
2560 | { |
---|
2561 | int max_blindex; /* index of last bit length code of non zero freq */ |
---|
2562 | |
---|
2563 | /* Determine the bit length frequencies for literal and distance trees */ |
---|
2564 | scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); |
---|
2565 | scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); |
---|
2566 | |
---|
2567 | /* Build the bit length tree: */ |
---|
2568 | build_tree(s, (tree_desc *)(&(s->bl_desc))); |
---|
2569 | /* opt_len now includes the length of the tree representations, except |
---|
2570 | * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. |
---|
2571 | */ |
---|
2572 | |
---|
2573 | /* Determine the number of bit length codes to send. The pkzip format |
---|
2574 | * requires that at least 4 bit length codes be sent. (appnote.txt says |
---|
2575 | * 3 but the actual value used is 4.) |
---|
2576 | */ |
---|
2577 | for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { |
---|
2578 | if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; |
---|
2579 | } |
---|
2580 | /* Update opt_len to include the bit length tree and counts */ |
---|
2581 | s->opt_len += 3*(max_blindex+1) + 5+5+4; |
---|
2582 | Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", |
---|
2583 | s->opt_len, s->static_len)); |
---|
2584 | |
---|
2585 | return max_blindex; |
---|
2586 | } |
---|
2587 | |
---|
2588 | /* =========================================================================== |
---|
2589 | * Send the header for a block using dynamic Huffman trees: the counts, the |
---|
2590 | * lengths of the bit length codes, the literal tree and the distance tree. |
---|
2591 | * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. |
---|
2592 | */ |
---|
2593 | local void send_all_trees(s, lcodes, dcodes, blcodes) |
---|
2594 | deflate_state *s; |
---|
2595 | int lcodes, dcodes, blcodes; /* number of codes for each tree */ |
---|
2596 | { |
---|
2597 | int rank; /* index in bl_order */ |
---|
2598 | |
---|
2599 | Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); |
---|
2600 | Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, |
---|
2601 | "too many codes"); |
---|
2602 | Tracev((stderr, "\nbl counts: ")); |
---|
2603 | send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ |
---|
2604 | send_bits(s, dcodes-1, 5); |
---|
2605 | send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ |
---|
2606 | for (rank = 0; rank < blcodes; rank++) { |
---|
2607 | Tracev((stderr, "\nbl code %2d ", bl_order[rank])); |
---|
2608 | send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); |
---|
2609 | } |
---|
2610 | Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); |
---|
2611 | |
---|
2612 | send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ |
---|
2613 | Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); |
---|
2614 | |
---|
2615 | send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ |
---|
2616 | Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); |
---|
2617 | } |
---|
2618 | |
---|
2619 | /* =========================================================================== |
---|
2620 | * Send a stored block |
---|
2621 | */ |
---|
2622 | void _tr_stored_block(s, buf, stored_len, eof) |
---|
2623 | deflate_state *s; |
---|
2624 | charf *buf; /* input block */ |
---|
2625 | ulg stored_len; /* length of input block */ |
---|
2626 | int eof; /* true if this is the last block for a file */ |
---|
2627 | { |
---|
2628 | send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ |
---|
2629 | s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; |
---|
2630 | s->compressed_len += (stored_len + 4) << 3; |
---|
2631 | |
---|
2632 | copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ |
---|
2633 | } |
---|
2634 | |
---|
2635 | /* Send just the `stored block' type code without any length bytes or data. |
---|
2636 | */ |
---|
2637 | void _tr_stored_type_only(s) |
---|
2638 | deflate_state *s; |
---|
2639 | { |
---|
2640 | send_bits(s, (STORED_BLOCK << 1), 3); |
---|
2641 | bi_windup(s); |
---|
2642 | s->compressed_len = (s->compressed_len + 3) & ~7L; |
---|
2643 | } |
---|
2644 | |
---|
2645 | |
---|
2646 | /* =========================================================================== |
---|
2647 | * Send one empty static block to give enough lookahead for inflate. |
---|
2648 | * This takes 10 bits, of which 7 may remain in the bit buffer. |
---|
2649 | * The current inflate code requires 9 bits of lookahead. If the |
---|
2650 | * last two codes for the previous block (real code plus EOB) were coded |
---|
2651 | * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode |
---|
2652 | * the last real code. In this case we send two empty static blocks instead |
---|
2653 | * of one. (There are no problems if the previous block is stored or fixed.) |
---|
2654 | * To simplify the code, we assume the worst case of last real code encoded |
---|
2655 | * on one bit only. |
---|
2656 | */ |
---|
2657 | void _tr_align(s) |
---|
2658 | deflate_state *s; |
---|
2659 | { |
---|
2660 | send_bits(s, STATIC_TREES<<1, 3); |
---|
2661 | send_code(s, END_BLOCK, static_ltree); |
---|
2662 | s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ |
---|
2663 | bi_flush(s); |
---|
2664 | /* Of the 10 bits for the empty block, we have already sent |
---|
2665 | * (10 - bi_valid) bits. The lookahead for the last real code (before |
---|
2666 | * the EOB of the previous block) was thus at least one plus the length |
---|
2667 | * of the EOB plus what we have just sent of the empty static block. |
---|
2668 | */ |
---|
2669 | if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { |
---|
2670 | send_bits(s, STATIC_TREES<<1, 3); |
---|
2671 | send_code(s, END_BLOCK, static_ltree); |
---|
2672 | s->compressed_len += 10L; |
---|
2673 | bi_flush(s); |
---|
2674 | } |
---|
2675 | s->last_eob_len = 7; |
---|
2676 | } |
---|
2677 | |
---|
2678 | /* =========================================================================== |
---|
2679 | * Determine the best encoding for the current block: dynamic trees, static |
---|
2680 | * trees or store, and output the encoded block to the zip file. This function |
---|
2681 | * returns the total compressed length for the file so far. |
---|
2682 | */ |
---|
2683 | ulg _tr_flush_block(s, buf, stored_len, eof) |
---|
2684 | deflate_state *s; |
---|
2685 | charf *buf; /* input block, or NULL if too old */ |
---|
2686 | ulg stored_len; /* length of input block */ |
---|
2687 | int eof; /* true if this is the last block for a file */ |
---|
2688 | { |
---|
2689 | ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ |
---|
2690 | int max_blindex = 0; /* index of last bit length code of non zero freq */ |
---|
2691 | |
---|
2692 | /* Build the Huffman trees unless a stored block is forced */ |
---|
2693 | if (s->level > 0) { |
---|
2694 | |
---|
2695 | /* Check if the file is ascii or binary */ |
---|
2696 | if (s->data_type == Z_UNKNOWN) set_data_type(s); |
---|
2697 | |
---|
2698 | /* Construct the literal and distance trees */ |
---|
2699 | build_tree(s, (tree_desc *)(&(s->l_desc))); |
---|
2700 | Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, |
---|
2701 | s->static_len)); |
---|
2702 | |
---|
2703 | build_tree(s, (tree_desc *)(&(s->d_desc))); |
---|
2704 | Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, |
---|
2705 | s->static_len)); |
---|
2706 | /* At this point, opt_len and static_len are the total bit lengths of |
---|
2707 | * the compressed block data, excluding the tree representations. |
---|
2708 | */ |
---|
2709 | |
---|
2710 | /* Build the bit length tree for the above two trees, and get the index |
---|
2711 | * in bl_order of the last bit length code to send. |
---|
2712 | */ |
---|
2713 | max_blindex = build_bl_tree(s); |
---|
2714 | |
---|
2715 | /* Determine the best encoding. Compute first the block length in bytes*/ |
---|
2716 | opt_lenb = (s->opt_len+3+7)>>3; |
---|
2717 | static_lenb = (s->static_len+3+7)>>3; |
---|
2718 | |
---|
2719 | Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", |
---|
2720 | opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, |
---|
2721 | s->last_lit)); |
---|
2722 | |
---|
2723 | if (static_lenb <= opt_lenb) opt_lenb = static_lenb; |
---|
2724 | |
---|
2725 | } else { |
---|
2726 | Assert(buf != (char*)0, "lost buf"); |
---|
2727 | opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ |
---|
2728 | } |
---|
2729 | |
---|
2730 | /* If compression failed and this is the first and last block, |
---|
2731 | * and if the .zip file can be seeked (to rewrite the local header), |
---|
2732 | * the whole file is transformed into a stored file: |
---|
2733 | */ |
---|
2734 | #ifdef STORED_FILE_OK |
---|
2735 | # ifdef FORCE_STORED_FILE |
---|
2736 | if (eof && s->compressed_len == 0L) { /* force stored file */ |
---|
2737 | # else |
---|
2738 | if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { |
---|
2739 | # endif |
---|
2740 | /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ |
---|
2741 | if (buf == (charf*)0) error ("block vanished"); |
---|
2742 | |
---|
2743 | copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ |
---|
2744 | s->compressed_len = stored_len << 3; |
---|
2745 | s->method = STORED; |
---|
2746 | } else |
---|
2747 | #endif /* STORED_FILE_OK */ |
---|
2748 | |
---|
2749 | #ifdef FORCE_STORED |
---|
2750 | if (buf != (char*)0) { /* force stored block */ |
---|
2751 | #else |
---|
2752 | if (stored_len+4 <= opt_lenb && buf != (char*)0) { |
---|
2753 | /* 4: two words for the lengths */ |
---|
2754 | #endif |
---|
2755 | /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. |
---|
2756 | * Otherwise we can't have processed more than WSIZE input bytes since |
---|
2757 | * the last block flush, because compression would have been |
---|
2758 | * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to |
---|
2759 | * transform a block into a stored block. |
---|
2760 | */ |
---|
2761 | _tr_stored_block(s, buf, stored_len, eof); |
---|
2762 | |
---|
2763 | #ifdef FORCE_STATIC |
---|
2764 | } else if (static_lenb >= 0) { /* force static trees */ |
---|
2765 | #else |
---|
2766 | } else if (static_lenb == opt_lenb) { |
---|
2767 | #endif |
---|
2768 | send_bits(s, (STATIC_TREES<<1)+eof, 3); |
---|
2769 | compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); |
---|
2770 | s->compressed_len += 3 + s->static_len; |
---|
2771 | } else { |
---|
2772 | send_bits(s, (DYN_TREES<<1)+eof, 3); |
---|
2773 | send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, |
---|
2774 | max_blindex+1); |
---|
2775 | compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); |
---|
2776 | s->compressed_len += 3 + s->opt_len; |
---|
2777 | } |
---|
2778 | Assert (s->compressed_len == s->bits_sent, "bad compressed size"); |
---|
2779 | init_block(s); |
---|
2780 | |
---|
2781 | if (eof) { |
---|
2782 | bi_windup(s); |
---|
2783 | s->compressed_len += 7; /* align on byte boundary */ |
---|
2784 | } |
---|
2785 | Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, |
---|
2786 | s->compressed_len-7*eof)); |
---|
2787 | |
---|
2788 | return s->compressed_len >> 3; |
---|
2789 | } |
---|
2790 | |
---|
2791 | /* =========================================================================== |
---|
2792 | * Save the match info and tally the frequency counts. Return true if |
---|
2793 | * the current block must be flushed. |
---|
2794 | */ |
---|
2795 | int _tr_tally (s, dist, lc) |
---|
2796 | deflate_state *s; |
---|
2797 | unsigned dist; /* distance of matched string */ |
---|
2798 | unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ |
---|
2799 | { |
---|
2800 | s->d_buf[s->last_lit] = (ush)dist; |
---|
2801 | s->l_buf[s->last_lit++] = (uch)lc; |
---|
2802 | if (dist == 0) { |
---|
2803 | /* lc is the unmatched char */ |
---|
2804 | s->dyn_ltree[lc].Freq++; |
---|
2805 | } else { |
---|
2806 | s->matches++; |
---|
2807 | /* Here, lc is the match length - MIN_MATCH */ |
---|
2808 | dist--; /* dist = match distance - 1 */ |
---|
2809 | Assert((ush)dist < (ush)MAX_DIST(s) && |
---|
2810 | (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && |
---|
2811 | (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); |
---|
2812 | |
---|
2813 | s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; |
---|
2814 | s->dyn_dtree[d_code(dist)].Freq++; |
---|
2815 | } |
---|
2816 | |
---|
2817 | /* Try to guess if it is profitable to stop the current block here */ |
---|
2818 | if (s->level > 2 && (s->last_lit & 0xfff) == 0) { |
---|
2819 | /* Compute an upper bound for the compressed length */ |
---|
2820 | ulg out_length = (ulg)s->last_lit*8L; |
---|
2821 | ulg in_length = (ulg)((long)s->strstart - s->block_start); |
---|
2822 | int dcode; |
---|
2823 | for (dcode = 0; dcode < D_CODES; dcode++) { |
---|
2824 | out_length += (ulg)s->dyn_dtree[dcode].Freq * |
---|
2825 | (5L+extra_dbits[dcode]); |
---|
2826 | } |
---|
2827 | out_length >>= 3; |
---|
2828 | Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", |
---|
2829 | s->last_lit, in_length, out_length, |
---|
2830 | 100L - out_length*100L/in_length)); |
---|
2831 | if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; |
---|
2832 | } |
---|
2833 | return (s->last_lit == s->lit_bufsize-1); |
---|
2834 | /* We avoid equality with lit_bufsize because of wraparound at 64K |
---|
2835 | * on 16 bit machines and because stored blocks are restricted to |
---|
2836 | * 64K-1 bytes. |
---|
2837 | */ |
---|
2838 | } |
---|
2839 | |
---|
2840 | /* =========================================================================== |
---|
2841 | * Send the block data compressed using the given Huffman trees |
---|
2842 | */ |
---|
2843 | local void compress_block(s, ltree, dtree) |
---|
2844 | deflate_state *s; |
---|
2845 | ct_data *ltree; /* literal tree */ |
---|
2846 | ct_data *dtree; /* distance tree */ |
---|
2847 | { |
---|
2848 | unsigned dist; /* distance of matched string */ |
---|
2849 | int lc; /* match length or unmatched char (if dist == 0) */ |
---|
2850 | unsigned lx = 0; /* running index in l_buf */ |
---|
2851 | unsigned code; /* the code to send */ |
---|
2852 | int extra; /* number of extra bits to send */ |
---|
2853 | |
---|
2854 | if (s->last_lit != 0) do { |
---|
2855 | dist = s->d_buf[lx]; |
---|
2856 | lc = s->l_buf[lx++]; |
---|
2857 | if (dist == 0) { |
---|
2858 | send_code(s, lc, ltree); /* send a literal byte */ |
---|
2859 | Tracecv(isgraph(lc), (stderr," '%c' ", lc)); |
---|
2860 | } else { |
---|
2861 | /* Here, lc is the match length - MIN_MATCH */ |
---|
2862 | code = length_code[lc]; |
---|
2863 | send_code(s, code+LITERALS+1, ltree); /* send the length code */ |
---|
2864 | extra = extra_lbits[code]; |
---|
2865 | if (extra != 0) { |
---|
2866 | lc -= base_length[code]; |
---|
2867 | send_bits(s, lc, extra); /* send the extra length bits */ |
---|
2868 | } |
---|
2869 | dist--; /* dist is now the match distance - 1 */ |
---|
2870 | code = d_code(dist); |
---|
2871 | Assert (code < D_CODES, "bad d_code"); |
---|
2872 | |
---|
2873 | send_code(s, code, dtree); /* send the distance code */ |
---|
2874 | extra = extra_dbits[code]; |
---|
2875 | if (extra != 0) { |
---|
2876 | dist -= base_dist[code]; |
---|
2877 | send_bits(s, dist, extra); /* send the extra distance bits */ |
---|
2878 | } |
---|
2879 | } /* literal or match pair ? */ |
---|
2880 | |
---|
2881 | /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ |
---|
2882 | Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); |
---|
2883 | |
---|
2884 | } while (lx < s->last_lit); |
---|
2885 | |
---|
2886 | send_code(s, END_BLOCK, ltree); |
---|
2887 | s->last_eob_len = ltree[END_BLOCK].Len; |
---|
2888 | } |
---|
2889 | |
---|
2890 | /* =========================================================================== |
---|
2891 | * Set the data type to ASCII or BINARY, using a crude approximation: |
---|
2892 | * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. |
---|
2893 | * IN assertion: the fields freq of dyn_ltree are set and the total of all |
---|
2894 | * frequencies does not exceed 64K (to fit in an int on 16 bit machines). |
---|
2895 | */ |
---|
2896 | local void set_data_type(s) |
---|
2897 | deflate_state *s; |
---|
2898 | { |
---|
2899 | int n = 0; |
---|
2900 | unsigned ascii_freq = 0; |
---|
2901 | unsigned bin_freq = 0; |
---|
2902 | while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; |
---|
2903 | while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; |
---|
2904 | while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; |
---|
2905 | s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); |
---|
2906 | } |
---|
2907 | |
---|
2908 | /* =========================================================================== |
---|
2909 | * Reverse the first len bits of a code, using straightforward code (a faster |
---|
2910 | * method would use a table) |
---|
2911 | * IN assertion: 1 <= len <= 15 |
---|
2912 | */ |
---|
2913 | local unsigned bi_reverse(code, len) |
---|
2914 | unsigned code; /* the value to invert */ |
---|
2915 | int len; /* its bit length */ |
---|
2916 | { |
---|
2917 | register unsigned res = 0; |
---|
2918 | do { |
---|
2919 | res |= code & 1; |
---|
2920 | code >>= 1, res <<= 1; |
---|
2921 | } while (--len > 0); |
---|
2922 | return res >> 1; |
---|
2923 | } |
---|
2924 | |
---|
2925 | /* =========================================================================== |
---|
2926 | * Flush the bit buffer, keeping at most 7 bits in it. |
---|
2927 | */ |
---|
2928 | local void bi_flush(s) |
---|
2929 | deflate_state *s; |
---|
2930 | { |
---|
2931 | if (s->bi_valid == 16) { |
---|
2932 | put_short(s, s->bi_buf); |
---|
2933 | s->bi_buf = 0; |
---|
2934 | s->bi_valid = 0; |
---|
2935 | } else if (s->bi_valid >= 8) { |
---|
2936 | put_byte(s, (Byte)s->bi_buf); |
---|
2937 | s->bi_buf >>= 8; |
---|
2938 | s->bi_valid -= 8; |
---|
2939 | } |
---|
2940 | } |
---|
2941 | |
---|
2942 | /* =========================================================================== |
---|
2943 | * Flush the bit buffer and align the output on a byte boundary |
---|
2944 | */ |
---|
2945 | local void bi_windup(s) |
---|
2946 | deflate_state *s; |
---|
2947 | { |
---|
2948 | if (s->bi_valid > 8) { |
---|
2949 | put_short(s, s->bi_buf); |
---|
2950 | } else if (s->bi_valid > 0) { |
---|
2951 | put_byte(s, (Byte)s->bi_buf); |
---|
2952 | } |
---|
2953 | s->bi_buf = 0; |
---|
2954 | s->bi_valid = 0; |
---|
2955 | #ifdef DEBUG_ZLIB |
---|
2956 | s->bits_sent = (s->bits_sent+7) & ~7; |
---|
2957 | #endif |
---|
2958 | } |
---|
2959 | |
---|
2960 | /* =========================================================================== |
---|
2961 | * Copy a stored block, storing first the length and its |
---|
2962 | * one's complement if requested. |
---|
2963 | */ |
---|
2964 | local void copy_block(s, buf, len, header) |
---|
2965 | deflate_state *s; |
---|
2966 | charf *buf; /* the input data */ |
---|
2967 | unsigned len; /* its length */ |
---|
2968 | int header; /* true if block header must be written */ |
---|
2969 | { |
---|
2970 | bi_windup(s); /* align on byte boundary */ |
---|
2971 | s->last_eob_len = 8; /* enough lookahead for inflate */ |
---|
2972 | |
---|
2973 | if (header) { |
---|
2974 | put_short(s, (ush)len); |
---|
2975 | put_short(s, (ush)~len); |
---|
2976 | #ifdef DEBUG_ZLIB |
---|
2977 | s->bits_sent += 2*16; |
---|
2978 | #endif |
---|
2979 | } |
---|
2980 | #ifdef DEBUG_ZLIB |
---|
2981 | s->bits_sent += (ulg)len<<3; |
---|
2982 | #endif |
---|
2983 | /* bundle up the put_byte(s, *buf++) calls */ |
---|
2984 | zmemcpy(&s->pending_buf[s->pending], buf, len); |
---|
2985 | s->pending += len; |
---|
2986 | } |
---|
2987 | /* --- trees.c */ |
---|
2988 | |
---|
2989 | /* +++ inflate.c */ |
---|
2990 | /* inflate.c -- zlib interface to inflate modules |
---|
2991 | * Copyright (C) 1995-1996 Mark Adler |
---|
2992 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
2993 | */ |
---|
2994 | |
---|
2995 | /* #include "zutil.h" */ |
---|
2996 | |
---|
2997 | /* +++ infblock.h */ |
---|
2998 | /* infblock.h -- header to use infblock.c |
---|
2999 | * Copyright (C) 1995-1996 Mark Adler |
---|
3000 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
3001 | */ |
---|
3002 | |
---|
3003 | /* WARNING: this file should *not* be used by applications. It is |
---|
3004 | part of the implementation of the compression library and is |
---|
3005 | subject to change. Applications should only use zlib.h. |
---|
3006 | */ |
---|
3007 | |
---|
3008 | struct inflate_blocks_state; |
---|
3009 | typedef struct inflate_blocks_state FAR inflate_blocks_statef; |
---|
3010 | |
---|
3011 | extern inflate_blocks_statef * inflate_blocks_new OF(( |
---|
3012 | z_streamp z, |
---|
3013 | check_func c, /* check function */ |
---|
3014 | uInt w)); /* window size */ |
---|
3015 | |
---|
3016 | extern int inflate_blocks OF(( |
---|
3017 | inflate_blocks_statef *, |
---|
3018 | z_streamp , |
---|
3019 | int)); /* initial return code */ |
---|
3020 | |
---|
3021 | extern void inflate_blocks_reset OF(( |
---|
3022 | inflate_blocks_statef *, |
---|
3023 | z_streamp , |
---|
3024 | uLongf *)); /* check value on output */ |
---|
3025 | |
---|
3026 | extern int inflate_blocks_free OF(( |
---|
3027 | inflate_blocks_statef *, |
---|
3028 | z_streamp , |
---|
3029 | uLongf *)); /* check value on output */ |
---|
3030 | |
---|
3031 | extern void inflate_set_dictionary OF(( |
---|
3032 | inflate_blocks_statef *s, |
---|
3033 | const Bytef *d, /* dictionary */ |
---|
3034 | uInt n)); /* dictionary length */ |
---|
3035 | |
---|
3036 | extern int inflate_addhistory OF(( |
---|
3037 | inflate_blocks_statef *, |
---|
3038 | z_streamp)); |
---|
3039 | |
---|
3040 | extern int inflate_packet_flush OF(( |
---|
3041 | inflate_blocks_statef *)); |
---|
3042 | /* --- infblock.h */ |
---|
3043 | |
---|
3044 | #ifndef NO_DUMMY_DECL |
---|
3045 | struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ |
---|
3046 | #endif |
---|
3047 | |
---|
3048 | /* inflate private state */ |
---|
3049 | struct internal_state { |
---|
3050 | |
---|
3051 | /* mode */ |
---|
3052 | enum { |
---|
3053 | METHOD, /* waiting for method byte */ |
---|
3054 | FLAG, /* waiting for flag byte */ |
---|
3055 | DICT4, /* four dictionary check bytes to go */ |
---|
3056 | DICT3, /* three dictionary check bytes to go */ |
---|
3057 | DICT2, /* two dictionary check bytes to go */ |
---|
3058 | DICT1, /* one dictionary check byte to go */ |
---|
3059 | DICT0, /* waiting for inflateSetDictionary */ |
---|
3060 | BLOCKS, /* decompressing blocks */ |
---|
3061 | CHECK4, /* four check bytes to go */ |
---|
3062 | CHECK3, /* three check bytes to go */ |
---|
3063 | CHECK2, /* two check bytes to go */ |
---|
3064 | CHECK1, /* one check byte to go */ |
---|
3065 | DONE, /* finished check, done */ |
---|
3066 | BAD} /* got an error--stay here */ |
---|
3067 | mode; /* current inflate mode */ |
---|
3068 | |
---|
3069 | /* mode dependent information */ |
---|
3070 | union { |
---|
3071 | uInt method; /* if FLAGS, method byte */ |
---|
3072 | struct { |
---|
3073 | uLong was; /* computed check value */ |
---|
3074 | uLong need; /* stream check value */ |
---|
3075 | } check; /* if CHECK, check values to compare */ |
---|
3076 | uInt marker; /* if BAD, inflateSync's marker bytes count */ |
---|
3077 | } sub; /* submode */ |
---|
3078 | |
---|
3079 | /* mode independent information */ |
---|
3080 | int nowrap; /* flag for no wrapper */ |
---|
3081 | uInt wbits; /* log2(window size) (8..15, defaults to 15) */ |
---|
3082 | inflate_blocks_statef |
---|
3083 | *blocks; /* current inflate_blocks state */ |
---|
3084 | |
---|
3085 | }; |
---|
3086 | |
---|
3087 | |
---|
3088 | int inflateReset(z) |
---|
3089 | z_streamp z; |
---|
3090 | { |
---|
3091 | uLong c; |
---|
3092 | |
---|
3093 | if (z == Z_NULL || z->state == Z_NULL) |
---|
3094 | return Z_STREAM_ERROR; |
---|
3095 | z->total_in = z->total_out = 0; |
---|
3096 | z->msg = Z_NULL; |
---|
3097 | z->state->mode = z->state->nowrap ? BLOCKS : METHOD; |
---|
3098 | inflate_blocks_reset(z->state->blocks, z, &c); |
---|
3099 | Trace((stderr, "inflate: reset\n")); |
---|
3100 | return Z_OK; |
---|
3101 | } |
---|
3102 | |
---|
3103 | |
---|
3104 | int inflateEnd(z) |
---|
3105 | z_streamp z; |
---|
3106 | { |
---|
3107 | uLong c; |
---|
3108 | |
---|
3109 | if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) |
---|
3110 | return Z_STREAM_ERROR; |
---|
3111 | if (z->state->blocks != Z_NULL) |
---|
3112 | inflate_blocks_free(z->state->blocks, z, &c); |
---|
3113 | ZFREE(z, z->state); |
---|
3114 | z->state = Z_NULL; |
---|
3115 | Trace((stderr, "inflate: end\n")); |
---|
3116 | return Z_OK; |
---|
3117 | } |
---|
3118 | |
---|
3119 | |
---|
3120 | int inflateInit2_(z, w, version, stream_size) |
---|
3121 | z_streamp z; |
---|
3122 | int w; |
---|
3123 | const char *version; |
---|
3124 | int stream_size; |
---|
3125 | { |
---|
3126 | if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || |
---|
3127 | stream_size != sizeof(z_stream)) |
---|
3128 | return Z_VERSION_ERROR; |
---|
3129 | |
---|
3130 | /* initialize state */ |
---|
3131 | if (z == Z_NULL) |
---|
3132 | return Z_STREAM_ERROR; |
---|
3133 | z->msg = Z_NULL; |
---|
3134 | #ifndef NO_ZCFUNCS |
---|
3135 | if (z->zalloc == Z_NULL) |
---|
3136 | { |
---|
3137 | z->zalloc = zcalloc; |
---|
3138 | z->opaque = (voidpf)0; |
---|
3139 | } |
---|
3140 | if (z->zfree == Z_NULL) z->zfree = zcfree; |
---|
3141 | #endif |
---|
3142 | if ((z->state = (struct internal_state FAR *) |
---|
3143 | ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) |
---|
3144 | return Z_MEM_ERROR; |
---|
3145 | z->state->blocks = Z_NULL; |
---|
3146 | |
---|
3147 | /* handle undocumented nowrap option (no zlib header or check) */ |
---|
3148 | z->state->nowrap = 0; |
---|
3149 | if (w < 0) |
---|
3150 | { |
---|
3151 | w = - w; |
---|
3152 | z->state->nowrap = 1; |
---|
3153 | } |
---|
3154 | |
---|
3155 | /* set window size */ |
---|
3156 | if (w < 8 || w > 15) |
---|
3157 | { |
---|
3158 | inflateEnd(z); |
---|
3159 | return Z_STREAM_ERROR; |
---|
3160 | } |
---|
3161 | z->state->wbits = (uInt)w; |
---|
3162 | |
---|
3163 | /* create inflate_blocks state */ |
---|
3164 | if ((z->state->blocks = |
---|
3165 | inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) |
---|
3166 | == Z_NULL) |
---|
3167 | { |
---|
3168 | inflateEnd(z); |
---|
3169 | return Z_MEM_ERROR; |
---|
3170 | } |
---|
3171 | Trace((stderr, "inflate: allocated\n")); |
---|
3172 | |
---|
3173 | /* reset state */ |
---|
3174 | inflateReset(z); |
---|
3175 | return Z_OK; |
---|
3176 | } |
---|
3177 | |
---|
3178 | |
---|
3179 | int inflateInit_(z, version, stream_size) |
---|
3180 | z_streamp z; |
---|
3181 | const char *version; |
---|
3182 | int stream_size; |
---|
3183 | { |
---|
3184 | return inflateInit2_(z, DEF_WBITS, version, stream_size); |
---|
3185 | } |
---|
3186 | |
---|
3187 | |
---|
3188 | #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} |
---|
3189 | #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) |
---|
3190 | |
---|
3191 | int inflate(z, f) |
---|
3192 | z_streamp z; |
---|
3193 | int f; |
---|
3194 | { |
---|
3195 | int r; |
---|
3196 | uInt b; |
---|
3197 | |
---|
3198 | if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) |
---|
3199 | return Z_STREAM_ERROR; |
---|
3200 | r = Z_BUF_ERROR; |
---|
3201 | while (1) switch (z->state->mode) |
---|
3202 | { |
---|
3203 | case METHOD: |
---|
3204 | NEEDBYTE |
---|
3205 | if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) |
---|
3206 | { |
---|
3207 | z->state->mode = BAD; |
---|
3208 | z->msg = (char*)"unknown compression method"; |
---|
3209 | z->state->sub.marker = 5; /* can't try inflateSync */ |
---|
3210 | break; |
---|
3211 | } |
---|
3212 | if ((z->state->sub.method >> 4) + 8 > z->state->wbits) |
---|
3213 | { |
---|
3214 | z->state->mode = BAD; |
---|
3215 | z->msg = (char*)"invalid window size"; |
---|
3216 | z->state->sub.marker = 5; /* can't try inflateSync */ |
---|
3217 | break; |
---|
3218 | } |
---|
3219 | z->state->mode = FLAG; |
---|
3220 | case FLAG: |
---|
3221 | NEEDBYTE |
---|
3222 | b = NEXTBYTE; |
---|
3223 | if (((z->state->sub.method << 8) + b) % 31) |
---|
3224 | { |
---|
3225 | z->state->mode = BAD; |
---|
3226 | z->msg = (char*)"incorrect header check"; |
---|
3227 | z->state->sub.marker = 5; /* can't try inflateSync */ |
---|
3228 | break; |
---|
3229 | } |
---|
3230 | Trace((stderr, "inflate: zlib header ok\n")); |
---|
3231 | if (!(b & PRESET_DICT)) |
---|
3232 | { |
---|
3233 | z->state->mode = BLOCKS; |
---|
3234 | break; |
---|
3235 | } |
---|
3236 | z->state->mode = DICT4; |
---|
3237 | case DICT4: |
---|
3238 | NEEDBYTE |
---|
3239 | z->state->sub.check.need = (uLong)NEXTBYTE << 24; |
---|
3240 | z->state->mode = DICT3; |
---|
3241 | case DICT3: |
---|
3242 | NEEDBYTE |
---|
3243 | z->state->sub.check.need += (uLong)NEXTBYTE << 16; |
---|
3244 | z->state->mode = DICT2; |
---|
3245 | case DICT2: |
---|
3246 | NEEDBYTE |
---|
3247 | z->state->sub.check.need += (uLong)NEXTBYTE << 8; |
---|
3248 | z->state->mode = DICT1; |
---|
3249 | case DICT1: |
---|
3250 | NEEDBYTE |
---|
3251 | z->state->sub.check.need += (uLong)NEXTBYTE; |
---|
3252 | z->adler = z->state->sub.check.need; |
---|
3253 | z->state->mode = DICT0; |
---|
3254 | return Z_NEED_DICT; |
---|
3255 | case DICT0: |
---|
3256 | z->state->mode = BAD; |
---|
3257 | z->msg = (char*)"need dictionary"; |
---|
3258 | z->state->sub.marker = 0; /* can try inflateSync */ |
---|
3259 | return Z_STREAM_ERROR; |
---|
3260 | case BLOCKS: |
---|
3261 | r = inflate_blocks(z->state->blocks, z, r); |
---|
3262 | if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) |
---|
3263 | r = inflate_packet_flush(z->state->blocks); |
---|
3264 | if (r == Z_DATA_ERROR) |
---|
3265 | { |
---|
3266 | z->state->mode = BAD; |
---|
3267 | z->state->sub.marker = 0; /* can try inflateSync */ |
---|
3268 | break; |
---|
3269 | } |
---|
3270 | if (r != Z_STREAM_END) |
---|
3271 | return r; |
---|
3272 | r = Z_OK; |
---|
3273 | inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); |
---|
3274 | if (z->state->nowrap) |
---|
3275 | { |
---|
3276 | z->state->mode = DONE; |
---|
3277 | break; |
---|
3278 | } |
---|
3279 | z->state->mode = CHECK4; |
---|
3280 | case CHECK4: |
---|
3281 | NEEDBYTE |
---|
3282 | z->state->sub.check.need = (uLong)NEXTBYTE << 24; |
---|
3283 | z->state->mode = CHECK3; |
---|
3284 | case CHECK3: |
---|
3285 | NEEDBYTE |
---|
3286 | z->state->sub.check.need += (uLong)NEXTBYTE << 16; |
---|
3287 | z->state->mode = CHECK2; |
---|
3288 | case CHECK2: |
---|
3289 | NEEDBYTE |
---|
3290 | z->state->sub.check.need += (uLong)NEXTBYTE << 8; |
---|
3291 | z->state->mode = CHECK1; |
---|
3292 | case CHECK1: |
---|
3293 | NEEDBYTE |
---|
3294 | z->state->sub.check.need += (uLong)NEXTBYTE; |
---|
3295 | |
---|
3296 | if (z->state->sub.check.was != z->state->sub.check.need) |
---|
3297 | { |
---|
3298 | z->state->mode = BAD; |
---|
3299 | z->msg = (char*)"incorrect data check"; |
---|
3300 | z->state->sub.marker = 5; /* can't try inflateSync */ |
---|
3301 | break; |
---|
3302 | } |
---|
3303 | Trace((stderr, "inflate: zlib check ok\n")); |
---|
3304 | z->state->mode = DONE; |
---|
3305 | case DONE: |
---|
3306 | return Z_STREAM_END; |
---|
3307 | case BAD: |
---|
3308 | return Z_DATA_ERROR; |
---|
3309 | default: |
---|
3310 | return Z_STREAM_ERROR; |
---|
3311 | } |
---|
3312 | |
---|
3313 | empty: |
---|
3314 | if (f != Z_PACKET_FLUSH) |
---|
3315 | return r; |
---|
3316 | z->state->mode = BAD; |
---|
3317 | z->msg = (char *)"need more for packet flush"; |
---|
3318 | z->state->sub.marker = 0; /* can try inflateSync */ |
---|
3319 | return Z_DATA_ERROR; |
---|
3320 | } |
---|
3321 | |
---|
3322 | |
---|
3323 | int inflateSetDictionary(z, dictionary, dictLength) |
---|
3324 | z_streamp z; |
---|
3325 | const Bytef *dictionary; |
---|
3326 | uInt dictLength; |
---|
3327 | { |
---|
3328 | uInt length = dictLength; |
---|
3329 | |
---|
3330 | if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) |
---|
3331 | return Z_STREAM_ERROR; |
---|
3332 | |
---|
3333 | if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; |
---|
3334 | z->adler = 1L; |
---|
3335 | |
---|
3336 | if (length >= ((uInt)1<<z->state->wbits)) |
---|
3337 | { |
---|
3338 | length = (1<<z->state->wbits)-1; |
---|
3339 | dictionary += dictLength - length; |
---|
3340 | } |
---|
3341 | inflate_set_dictionary(z->state->blocks, dictionary, length); |
---|
3342 | z->state->mode = BLOCKS; |
---|
3343 | return Z_OK; |
---|
3344 | } |
---|
3345 | |
---|
3346 | /* |
---|
3347 | * This subroutine adds the data at next_in/avail_in to the output history |
---|
3348 | * without performing any output. The output buffer must be "caught up"; |
---|
3349 | * i.e. no pending output (hence s->read equals s->write), and the state must |
---|
3350 | * be BLOCKS (i.e. we should be willing to see the start of a series of |
---|
3351 | * BLOCKS). On exit, the output will also be caught up, and the checksum |
---|
3352 | * will have been updated if need be. |
---|
3353 | */ |
---|
3354 | |
---|
3355 | int inflateIncomp(z) |
---|
3356 | z_stream *z; |
---|
3357 | { |
---|
3358 | if (z->state->mode != BLOCKS) |
---|
3359 | return Z_DATA_ERROR; |
---|
3360 | return inflate_addhistory(z->state->blocks, z); |
---|
3361 | } |
---|
3362 | |
---|
3363 | |
---|
3364 | int inflateSync(z) |
---|
3365 | z_streamp z; |
---|
3366 | { |
---|
3367 | uInt n; /* number of bytes to look at */ |
---|
3368 | Bytef *p; /* pointer to bytes */ |
---|
3369 | uInt m; /* number of marker bytes found in a row */ |
---|
3370 | uLong r, w; /* temporaries to save total_in and total_out */ |
---|
3371 | |
---|
3372 | /* set up */ |
---|
3373 | if (z == Z_NULL || z->state == Z_NULL) |
---|
3374 | return Z_STREAM_ERROR; |
---|
3375 | if (z->state->mode != BAD) |
---|
3376 | { |
---|
3377 | z->state->mode = BAD; |
---|
3378 | z->state->sub.marker = 0; |
---|
3379 | } |
---|
3380 | if ((n = z->avail_in) == 0) |
---|
3381 | return Z_BUF_ERROR; |
---|
3382 | p = z->next_in; |
---|
3383 | m = z->state->sub.marker; |
---|
3384 | |
---|
3385 | /* search */ |
---|
3386 | while (n && m < 4) |
---|
3387 | { |
---|
3388 | if (*p == (Byte)(m < 2 ? 0 : 0xff)) |
---|
3389 | m++; |
---|
3390 | else if (*p) |
---|
3391 | m = 0; |
---|
3392 | else |
---|
3393 | m = 4 - m; |
---|
3394 | p++, n--; |
---|
3395 | } |
---|
3396 | |
---|
3397 | /* restore */ |
---|
3398 | z->total_in += p - z->next_in; |
---|
3399 | z->next_in = p; |
---|
3400 | z->avail_in = n; |
---|
3401 | z->state->sub.marker = m; |
---|
3402 | |
---|
3403 | /* return no joy or set up to restart on a new block */ |
---|
3404 | if (m != 4) |
---|
3405 | return Z_DATA_ERROR; |
---|
3406 | r = z->total_in; w = z->total_out; |
---|
3407 | inflateReset(z); |
---|
3408 | z->total_in = r; z->total_out = w; |
---|
3409 | z->state->mode = BLOCKS; |
---|
3410 | return Z_OK; |
---|
3411 | } |
---|
3412 | |
---|
3413 | #undef NEEDBYTE |
---|
3414 | #undef NEXTBYTE |
---|
3415 | /* --- inflate.c */ |
---|
3416 | |
---|
3417 | /* +++ infblock.c */ |
---|
3418 | /* infblock.c -- interpret and process block types to last block |
---|
3419 | * Copyright (C) 1995-1996 Mark Adler |
---|
3420 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
3421 | */ |
---|
3422 | |
---|
3423 | /* #include "zutil.h" */ |
---|
3424 | /* #include "infblock.h" */ |
---|
3425 | |
---|
3426 | /* +++ inftrees.h */ |
---|
3427 | /* inftrees.h -- header to use inftrees.c |
---|
3428 | * Copyright (C) 1995-1996 Mark Adler |
---|
3429 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
3430 | */ |
---|
3431 | |
---|
3432 | /* WARNING: this file should *not* be used by applications. It is |
---|
3433 | part of the implementation of the compression library and is |
---|
3434 | subject to change. Applications should only use zlib.h. |
---|
3435 | */ |
---|
3436 | |
---|
3437 | /* Huffman code lookup table entry--this entry is four bytes for machines |
---|
3438 | that have 16-bit pointers (e.g. PC's in the small or medium model). */ |
---|
3439 | |
---|
3440 | typedef struct inflate_huft_s FAR inflate_huft; |
---|
3441 | |
---|
3442 | struct inflate_huft_s { |
---|
3443 | union { |
---|
3444 | struct { |
---|
3445 | Byte Exop; /* number of extra bits or operation */ |
---|
3446 | Byte Bits; /* number of bits in this code or subcode */ |
---|
3447 | } what; |
---|
3448 | Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ |
---|
3449 | } word; /* 16-bit, 8 bytes for 32-bit machines) */ |
---|
3450 | union { |
---|
3451 | uInt Base; /* literal, length base, or distance base */ |
---|
3452 | inflate_huft *Next; /* pointer to next level of table */ |
---|
3453 | } more; |
---|
3454 | }; |
---|
3455 | |
---|
3456 | #ifdef DEBUG_ZLIB |
---|
3457 | extern uInt inflate_hufts; |
---|
3458 | #endif |
---|
3459 | |
---|
3460 | extern int inflate_trees_bits OF(( |
---|
3461 | uIntf *, /* 19 code lengths */ |
---|
3462 | uIntf *, /* bits tree desired/actual depth */ |
---|
3463 | inflate_huft * FAR *, /* bits tree result */ |
---|
3464 | z_streamp )); /* for zalloc, zfree functions */ |
---|
3465 | |
---|
3466 | extern int inflate_trees_dynamic OF(( |
---|
3467 | uInt, /* number of literal/length codes */ |
---|
3468 | uInt, /* number of distance codes */ |
---|
3469 | uIntf *, /* that many (total) code lengths */ |
---|
3470 | uIntf *, /* literal desired/actual bit depth */ |
---|
3471 | uIntf *, /* distance desired/actual bit depth */ |
---|
3472 | inflate_huft * FAR *, /* literal/length tree result */ |
---|
3473 | inflate_huft * FAR *, /* distance tree result */ |
---|
3474 | z_streamp )); /* for zalloc, zfree functions */ |
---|
3475 | |
---|
3476 | extern int inflate_trees_fixed OF(( |
---|
3477 | uIntf *, /* literal desired/actual bit depth */ |
---|
3478 | uIntf *, /* distance desired/actual bit depth */ |
---|
3479 | inflate_huft * FAR *, /* literal/length tree result */ |
---|
3480 | inflate_huft * FAR *)); /* distance tree result */ |
---|
3481 | |
---|
3482 | extern int inflate_trees_free OF(( |
---|
3483 | inflate_huft *, /* tables to free */ |
---|
3484 | z_streamp )); /* for zfree function */ |
---|
3485 | |
---|
3486 | /* --- inftrees.h */ |
---|
3487 | |
---|
3488 | /* +++ infcodes.h */ |
---|
3489 | /* infcodes.h -- header to use infcodes.c |
---|
3490 | * Copyright (C) 1995-1996 Mark Adler |
---|
3491 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
3492 | */ |
---|
3493 | |
---|
3494 | /* WARNING: this file should *not* be used by applications. It is |
---|
3495 | part of the implementation of the compression library and is |
---|
3496 | subject to change. Applications should only use zlib.h. |
---|
3497 | */ |
---|
3498 | |
---|
3499 | struct inflate_codes_state; |
---|
3500 | typedef struct inflate_codes_state FAR inflate_codes_statef; |
---|
3501 | |
---|
3502 | extern inflate_codes_statef *inflate_codes_new OF(( |
---|
3503 | uInt, uInt, |
---|
3504 | inflate_huft *, inflate_huft *, |
---|
3505 | z_streamp )); |
---|
3506 | |
---|
3507 | extern int inflate_codes OF(( |
---|
3508 | inflate_blocks_statef *, |
---|
3509 | z_streamp , |
---|
3510 | int)); |
---|
3511 | |
---|
3512 | extern void inflate_codes_free OF(( |
---|
3513 | inflate_codes_statef *, |
---|
3514 | z_streamp )); |
---|
3515 | |
---|
3516 | /* --- infcodes.h */ |
---|
3517 | |
---|
3518 | /* +++ infutil.h */ |
---|
3519 | /* infutil.h -- types and macros common to blocks and codes |
---|
3520 | * Copyright (C) 1995-1996 Mark Adler |
---|
3521 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
3522 | */ |
---|
3523 | |
---|
3524 | /* WARNING: this file should *not* be used by applications. It is |
---|
3525 | part of the implementation of the compression library and is |
---|
3526 | subject to change. Applications should only use zlib.h. |
---|
3527 | */ |
---|
3528 | |
---|
3529 | #ifndef _INFUTIL_H |
---|
3530 | #define _INFUTIL_H |
---|
3531 | |
---|
3532 | typedef enum { |
---|
3533 | TYPE, /* get type bits (3, including end bit) */ |
---|
3534 | LENS, /* get lengths for stored */ |
---|
3535 | STORED, /* processing stored block */ |
---|
3536 | TABLE, /* get table lengths */ |
---|
3537 | BTREE, /* get bit lengths tree for a dynamic block */ |
---|
3538 | DTREE, /* get length, distance trees for a dynamic block */ |
---|
3539 | CODES, /* processing fixed or dynamic block */ |
---|
3540 | DRY, /* output remaining window bytes */ |
---|
3541 | DONEB, /* finished last block, done */ |
---|
3542 | BADB} /* got a data error--stuck here */ |
---|
3543 | inflate_block_mode; |
---|
3544 | |
---|
3545 | /* inflate blocks semi-private state */ |
---|
3546 | struct inflate_blocks_state { |
---|
3547 | |
---|
3548 | /* mode */ |
---|
3549 | inflate_block_mode mode; /* current inflate_block mode */ |
---|
3550 | |
---|
3551 | /* mode dependent information */ |
---|
3552 | union { |
---|
3553 | uInt left; /* if STORED, bytes left to copy */ |
---|
3554 | struct { |
---|
3555 | uInt table; /* table lengths (14 bits) */ |
---|
3556 | uInt index; /* index into blens (or border) */ |
---|
3557 | uIntf *blens; /* bit lengths of codes */ |
---|
3558 | uInt bb; /* bit length tree depth */ |
---|
3559 | inflate_huft *tb; /* bit length decoding tree */ |
---|
3560 | } trees; /* if DTREE, decoding info for trees */ |
---|
3561 | struct { |
---|
3562 | inflate_huft *tl; |
---|
3563 | inflate_huft *td; /* trees to free */ |
---|
3564 | inflate_codes_statef |
---|
3565 | *codes; |
---|
3566 | } decode; /* if CODES, current state */ |
---|
3567 | } sub; /* submode */ |
---|
3568 | uInt last; /* true if this block is the last block */ |
---|
3569 | |
---|
3570 | /* mode independent information */ |
---|
3571 | uInt bitk; /* bits in bit buffer */ |
---|
3572 | uLong bitb; /* bit buffer */ |
---|
3573 | Bytef *window; /* sliding window */ |
---|
3574 | Bytef *end; /* one byte after sliding window */ |
---|
3575 | Bytef *read; /* window read pointer */ |
---|
3576 | Bytef *write; /* window write pointer */ |
---|
3577 | check_func checkfn; /* check function */ |
---|
3578 | uLong check; /* check on output */ |
---|
3579 | |
---|
3580 | }; |
---|
3581 | |
---|
3582 | |
---|
3583 | /* defines for inflate input/output */ |
---|
3584 | /* update pointers and return */ |
---|
3585 | #define UPDBITS {s->bitb=b;s->bitk=k;} |
---|
3586 | #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} |
---|
3587 | #define UPDOUT {s->write=q;} |
---|
3588 | #define UPDATE {UPDBITS UPDIN UPDOUT} |
---|
3589 | #define LEAVE {UPDATE return inflate_flush(s,z,r);} |
---|
3590 | /* get bytes and bits */ |
---|
3591 | #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} |
---|
3592 | #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} |
---|
3593 | #define NEXTBYTE (n--,*p++) |
---|
3594 | #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} |
---|
3595 | #define DUMPBITS(j) {b>>=(j);k-=(j);} |
---|
3596 | /* output bytes */ |
---|
3597 | #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) |
---|
3598 | #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} |
---|
3599 | #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} |
---|
3600 | #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} |
---|
3601 | #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} |
---|
3602 | #define OUTBYTE(a) {*q++=(Byte)(a);m--;} |
---|
3603 | /* load local pointers */ |
---|
3604 | #define LOAD {LOADIN LOADOUT} |
---|
3605 | |
---|
3606 | /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ |
---|
3607 | extern uInt inflate_mask[17]; |
---|
3608 | |
---|
3609 | /* copy as much as possible from the sliding window to the output area */ |
---|
3610 | extern int inflate_flush OF(( |
---|
3611 | inflate_blocks_statef *, |
---|
3612 | z_streamp , |
---|
3613 | int)); |
---|
3614 | |
---|
3615 | #ifndef NO_DUMMY_DECL |
---|
3616 | struct internal_state {int dummy;}; /* for buggy compilers */ |
---|
3617 | #endif |
---|
3618 | |
---|
3619 | #endif |
---|
3620 | /* --- infutil.h */ |
---|
3621 | |
---|
3622 | #ifndef NO_DUMMY_DECL |
---|
3623 | struct inflate_codes_state {int dummy;}; /* for buggy compilers */ |
---|
3624 | #endif |
---|
3625 | |
---|
3626 | /* Table for deflate from PKZIP's appnote.txt. */ |
---|
3627 | local const uInt border[] = { /* Order of the bit length code lengths */ |
---|
3628 | 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
---|
3629 | |
---|
3630 | /* |
---|
3631 | Notes beyond the 1.93a appnote.txt: |
---|
3632 | |
---|
3633 | 1. Distance pointers never point before the beginning of the output |
---|
3634 | stream. |
---|
3635 | 2. Distance pointers can point back across blocks, up to 32k away. |
---|
3636 | 3. There is an implied maximum of 7 bits for the bit length table and |
---|
3637 | 15 bits for the actual data. |
---|
3638 | 4. If only one code exists, then it is encoded using one bit. (Zero |
---|
3639 | would be more efficient, but perhaps a little confusing.) If two |
---|
3640 | codes exist, they are coded using one bit each (0 and 1). |
---|
3641 | 5. There is no way of sending zero distance codes--a dummy must be |
---|
3642 | sent if there are none. (History: a pre 2.0 version of PKZIP would |
---|
3643 | store blocks with no distance codes, but this was discovered to be |
---|
3644 | too harsh a criterion.) Valid only for 1.93a. 2.04c does allow |
---|
3645 | zero distance codes, which is sent as one code of zero bits in |
---|
3646 | length. |
---|
3647 | 6. There are up to 286 literal/length codes. Code 256 represents the |
---|
3648 | end-of-block. Note however that the static length tree defines |
---|
3649 | 288 codes just to fill out the Huffman codes. Codes 286 and 287 |
---|
3650 | cannot be used though, since there is no length base or extra bits |
---|
3651 | defined for them. Similarily, there are up to 30 distance codes. |
---|
3652 | However, static trees define 32 codes (all 5 bits) to fill out the |
---|
3653 | Huffman codes, but the last two had better not show up in the data. |
---|
3654 | 7. Unzip can check dynamic Huffman blocks for complete code sets. |
---|
3655 | The exception is that a single code would not be complete (see #4). |
---|
3656 | 8. The five bits following the block type is really the number of |
---|
3657 | literal codes sent minus 257. |
---|
3658 | 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits |
---|
3659 | (1+6+6). Therefore, to output three times the length, you output |
---|
3660 | three codes (1+1+1), whereas to output four times the same length, |
---|
3661 | you only need two codes (1+3). Hmm. |
---|
3662 | 10. In the tree reconstruction algorithm, Code = Code + Increment |
---|
3663 | only if BitLength(i) is not zero. (Pretty obvious.) |
---|
3664 | 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) |
---|
3665 | 12. Note: length code 284 can represent 227-258, but length code 285 |
---|
3666 | really is 258. The last length deserves its own, short code |
---|
3667 | since it gets used a lot in very redundant files. The length |
---|
3668 | 258 is special since 258 - 3 (the min match length) is 255. |
---|
3669 | 13. The literal/length and distance code bit lengths are read as a |
---|
3670 | single stream of lengths. It is possible (and advantageous) for |
---|
3671 | a repeat code (16, 17, or 18) to go across the boundary between |
---|
3672 | the two sets of lengths. |
---|
3673 | */ |
---|
3674 | |
---|
3675 | |
---|
3676 | void inflate_blocks_reset(s, z, c) |
---|
3677 | inflate_blocks_statef *s; |
---|
3678 | z_streamp z; |
---|
3679 | uLongf *c; |
---|
3680 | { |
---|
3681 | if (s->checkfn != Z_NULL) |
---|
3682 | *c = s->check; |
---|
3683 | if (s->mode == BTREE || s->mode == DTREE) |
---|
3684 | ZFREE(z, s->sub.trees.blens); |
---|
3685 | if (s->mode == CODES) |
---|
3686 | { |
---|
3687 | inflate_codes_free(s->sub.decode.codes, z); |
---|
3688 | inflate_trees_free(s->sub.decode.td, z); |
---|
3689 | inflate_trees_free(s->sub.decode.tl, z); |
---|
3690 | } |
---|
3691 | s->mode = TYPE; |
---|
3692 | s->bitk = 0; |
---|
3693 | s->bitb = 0; |
---|
3694 | s->read = s->write = s->window; |
---|
3695 | if (s->checkfn != Z_NULL) |
---|
3696 | z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); |
---|
3697 | Trace((stderr, "inflate: blocks reset\n")); |
---|
3698 | } |
---|
3699 | |
---|
3700 | |
---|
3701 | inflate_blocks_statef *inflate_blocks_new(z, c, w) |
---|
3702 | z_streamp z; |
---|
3703 | check_func c; |
---|
3704 | uInt w; |
---|
3705 | { |
---|
3706 | inflate_blocks_statef *s; |
---|
3707 | |
---|
3708 | if ((s = (inflate_blocks_statef *)ZALLOC |
---|
3709 | (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) |
---|
3710 | return s; |
---|
3711 | if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) |
---|
3712 | { |
---|
3713 | ZFREE(z, s); |
---|
3714 | return Z_NULL; |
---|
3715 | } |
---|
3716 | s->end = s->window + w; |
---|
3717 | s->checkfn = c; |
---|
3718 | s->mode = TYPE; |
---|
3719 | Trace((stderr, "inflate: blocks allocated\n")); |
---|
3720 | inflate_blocks_reset(s, z, &s->check); |
---|
3721 | return s; |
---|
3722 | } |
---|
3723 | |
---|
3724 | |
---|
3725 | #ifdef DEBUG_ZLIB |
---|
3726 | extern uInt inflate_hufts; |
---|
3727 | #endif |
---|
3728 | int inflate_blocks(s, z, r) |
---|
3729 | inflate_blocks_statef *s; |
---|
3730 | z_streamp z; |
---|
3731 | int r; |
---|
3732 | { |
---|
3733 | uInt t; /* temporary storage */ |
---|
3734 | uLong b; /* bit buffer */ |
---|
3735 | uInt k; /* bits in bit buffer */ |
---|
3736 | Bytef *p; /* input data pointer */ |
---|
3737 | uInt n; /* bytes available there */ |
---|
3738 | Bytef *q; /* output window write pointer */ |
---|
3739 | uInt m; /* bytes to end of window or read pointer */ |
---|
3740 | |
---|
3741 | /* copy input/output information to locals (UPDATE macro restores) */ |
---|
3742 | LOAD |
---|
3743 | |
---|
3744 | /* process input based on current state */ |
---|
3745 | while (1) switch (s->mode) |
---|
3746 | { |
---|
3747 | case TYPE: |
---|
3748 | NEEDBITS(3) |
---|
3749 | t = (uInt)b & 7; |
---|
3750 | s->last = t & 1; |
---|
3751 | switch (t >> 1) |
---|
3752 | { |
---|
3753 | case 0: /* stored */ |
---|
3754 | Trace((stderr, "inflate: stored block%s\n", |
---|
3755 | s->last ? " (last)" : "")); |
---|
3756 | DUMPBITS(3) |
---|
3757 | t = k & 7; /* go to byte boundary */ |
---|
3758 | DUMPBITS(t) |
---|
3759 | s->mode = LENS; /* get length of stored block */ |
---|
3760 | break; |
---|
3761 | case 1: /* fixed */ |
---|
3762 | Trace((stderr, "inflate: fixed codes block%s\n", |
---|
3763 | s->last ? " (last)" : "")); |
---|
3764 | { |
---|
3765 | uInt bl, bd; |
---|
3766 | inflate_huft *tl, *td; |
---|
3767 | |
---|
3768 | inflate_trees_fixed(&bl, &bd, &tl, &td); |
---|
3769 | s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); |
---|
3770 | if (s->sub.decode.codes == Z_NULL) |
---|
3771 | { |
---|
3772 | r = Z_MEM_ERROR; |
---|
3773 | LEAVE |
---|
3774 | } |
---|
3775 | s->sub.decode.tl = Z_NULL; /* don't try to free these */ |
---|
3776 | s->sub.decode.td = Z_NULL; |
---|
3777 | } |
---|
3778 | DUMPBITS(3) |
---|
3779 | s->mode = CODES; |
---|
3780 | break; |
---|
3781 | case 2: /* dynamic */ |
---|
3782 | Trace((stderr, "inflate: dynamic codes block%s\n", |
---|
3783 | s->last ? " (last)" : "")); |
---|
3784 | DUMPBITS(3) |
---|
3785 | s->mode = TABLE; |
---|
3786 | break; |
---|
3787 | case 3: /* illegal */ |
---|
3788 | DUMPBITS(3) |
---|
3789 | s->mode = BADB; |
---|
3790 | z->msg = (char*)"invalid block type"; |
---|
3791 | r = Z_DATA_ERROR; |
---|
3792 | LEAVE |
---|
3793 | } |
---|
3794 | break; |
---|
3795 | case LENS: |
---|
3796 | NEEDBITS(32) |
---|
3797 | if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) |
---|
3798 | { |
---|
3799 | s->mode = BADB; |
---|
3800 | z->msg = (char*)"invalid stored block lengths"; |
---|
3801 | r = Z_DATA_ERROR; |
---|
3802 | LEAVE |
---|
3803 | } |
---|
3804 | s->sub.left = (uInt)b & 0xffff; |
---|
3805 | b = k = 0; /* dump bits */ |
---|
3806 | Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); |
---|
3807 | s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); |
---|
3808 | break; |
---|
3809 | case STORED: |
---|
3810 | if (n == 0) |
---|
3811 | LEAVE |
---|
3812 | NEEDOUT |
---|
3813 | t = s->sub.left; |
---|
3814 | if (t > n) t = n; |
---|
3815 | if (t > m) t = m; |
---|
3816 | zmemcpy(q, p, t); |
---|
3817 | p += t; n -= t; |
---|
3818 | q += t; m -= t; |
---|
3819 | if ((s->sub.left -= t) != 0) |
---|
3820 | break; |
---|
3821 | Tracev((stderr, "inflate: stored end, %lu total out\n", |
---|
3822 | z->total_out + (q >= s->read ? q - s->read : |
---|
3823 | (s->end - s->read) + (q - s->window)))); |
---|
3824 | s->mode = s->last ? DRY : TYPE; |
---|
3825 | break; |
---|
3826 | case TABLE: |
---|
3827 | NEEDBITS(14) |
---|
3828 | s->sub.trees.table = t = (uInt)b & 0x3fff; |
---|
3829 | #ifndef PKZIP_BUG_WORKAROUND |
---|
3830 | if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) |
---|
3831 | { |
---|
3832 | s->mode = BADB; |
---|
3833 | z->msg = (char*)"too many length or distance symbols"; |
---|
3834 | r = Z_DATA_ERROR; |
---|
3835 | LEAVE |
---|
3836 | } |
---|
3837 | #endif |
---|
3838 | t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); |
---|
3839 | if (t < 19) |
---|
3840 | t = 19; |
---|
3841 | if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) |
---|
3842 | { |
---|
3843 | r = Z_MEM_ERROR; |
---|
3844 | LEAVE |
---|
3845 | } |
---|
3846 | DUMPBITS(14) |
---|
3847 | s->sub.trees.index = 0; |
---|
3848 | Tracev((stderr, "inflate: table sizes ok\n")); |
---|
3849 | s->mode = BTREE; |
---|
3850 | case BTREE: |
---|
3851 | while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) |
---|
3852 | { |
---|
3853 | NEEDBITS(3) |
---|
3854 | s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; |
---|
3855 | DUMPBITS(3) |
---|
3856 | } |
---|
3857 | while (s->sub.trees.index < 19) |
---|
3858 | s->sub.trees.blens[border[s->sub.trees.index++]] = 0; |
---|
3859 | s->sub.trees.bb = 7; |
---|
3860 | t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, |
---|
3861 | &s->sub.trees.tb, z); |
---|
3862 | if (t != Z_OK) |
---|
3863 | { |
---|
3864 | ZFREE(z, s->sub.trees.blens); |
---|
3865 | r = t; |
---|
3866 | if (r == Z_DATA_ERROR) |
---|
3867 | s->mode = BADB; |
---|
3868 | LEAVE |
---|
3869 | } |
---|
3870 | s->sub.trees.index = 0; |
---|
3871 | Tracev((stderr, "inflate: bits tree ok\n")); |
---|
3872 | s->mode = DTREE; |
---|
3873 | case DTREE: |
---|
3874 | while (t = s->sub.trees.table, |
---|
3875 | s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) |
---|
3876 | { |
---|
3877 | inflate_huft *h; |
---|
3878 | uInt i, j, c; |
---|
3879 | |
---|
3880 | t = s->sub.trees.bb; |
---|
3881 | NEEDBITS(t) |
---|
3882 | h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); |
---|
3883 | t = h->word.what.Bits; |
---|
3884 | c = h->more.Base; |
---|
3885 | if (c < 16) |
---|
3886 | { |
---|
3887 | DUMPBITS(t) |
---|
3888 | s->sub.trees.blens[s->sub.trees.index++] = c; |
---|
3889 | } |
---|
3890 | else /* c == 16..18 */ |
---|
3891 | { |
---|
3892 | i = c == 18 ? 7 : c - 14; |
---|
3893 | j = c == 18 ? 11 : 3; |
---|
3894 | NEEDBITS(t + i) |
---|
3895 | DUMPBITS(t) |
---|
3896 | j += (uInt)b & inflate_mask[i]; |
---|
3897 | DUMPBITS(i) |
---|
3898 | i = s->sub.trees.index; |
---|
3899 | t = s->sub.trees.table; |
---|
3900 | if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || |
---|
3901 | (c == 16 && i < 1)) |
---|
3902 | { |
---|
3903 | inflate_trees_free(s->sub.trees.tb, z); |
---|
3904 | ZFREE(z, s->sub.trees.blens); |
---|
3905 | s->mode = BADB; |
---|
3906 | z->msg = (char*)"invalid bit length repeat"; |
---|
3907 | r = Z_DATA_ERROR; |
---|
3908 | LEAVE |
---|
3909 | } |
---|
3910 | c = c == 16 ? s->sub.trees.blens[i - 1] : 0; |
---|
3911 | do { |
---|
3912 | s->sub.trees.blens[i++] = c; |
---|
3913 | } while (--j); |
---|
3914 | s->sub.trees.index = i; |
---|
3915 | } |
---|
3916 | } |
---|
3917 | inflate_trees_free(s->sub.trees.tb, z); |
---|
3918 | s->sub.trees.tb = Z_NULL; |
---|
3919 | { |
---|
3920 | uInt bl, bd; |
---|
3921 | inflate_huft *tl, *td; |
---|
3922 | inflate_codes_statef *c; |
---|
3923 | |
---|
3924 | bl = 9; /* must be <= 9 for lookahead assumptions */ |
---|
3925 | bd = 6; /* must be <= 9 for lookahead assumptions */ |
---|
3926 | t = s->sub.trees.table; |
---|
3927 | #ifdef DEBUG_ZLIB |
---|
3928 | inflate_hufts = 0; |
---|
3929 | #endif |
---|
3930 | t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), |
---|
3931 | s->sub.trees.blens, &bl, &bd, &tl, &td, z); |
---|
3932 | ZFREE(z, s->sub.trees.blens); |
---|
3933 | if (t != Z_OK) |
---|
3934 | { |
---|
3935 | if (t == (uInt)Z_DATA_ERROR) |
---|
3936 | s->mode = BADB; |
---|
3937 | r = t; |
---|
3938 | LEAVE |
---|
3939 | } |
---|
3940 | Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", |
---|
3941 | inflate_hufts, sizeof(inflate_huft))); |
---|
3942 | if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) |
---|
3943 | { |
---|
3944 | inflate_trees_free(td, z); |
---|
3945 | inflate_trees_free(tl, z); |
---|
3946 | r = Z_MEM_ERROR; |
---|
3947 | LEAVE |
---|
3948 | } |
---|
3949 | s->sub.decode.codes = c; |
---|
3950 | s->sub.decode.tl = tl; |
---|
3951 | s->sub.decode.td = td; |
---|
3952 | } |
---|
3953 | s->mode = CODES; |
---|
3954 | case CODES: |
---|
3955 | UPDATE |
---|
3956 | if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) |
---|
3957 | return inflate_flush(s, z, r); |
---|
3958 | r = Z_OK; |
---|
3959 | inflate_codes_free(s->sub.decode.codes, z); |
---|
3960 | inflate_trees_free(s->sub.decode.td, z); |
---|
3961 | inflate_trees_free(s->sub.decode.tl, z); |
---|
3962 | LOAD |
---|
3963 | Tracev((stderr, "inflate: codes end, %lu total out\n", |
---|
3964 | z->total_out + (q >= s->read ? q - s->read : |
---|
3965 | (s->end - s->read) + (q - s->window)))); |
---|
3966 | if (!s->last) |
---|
3967 | { |
---|
3968 | s->mode = TYPE; |
---|
3969 | break; |
---|
3970 | } |
---|
3971 | if (k > 7) /* return unused byte, if any */ |
---|
3972 | { |
---|
3973 | Assert(k < 16, "inflate_codes grabbed too many bytes") |
---|
3974 | k -= 8; |
---|
3975 | n++; |
---|
3976 | p--; /* can always return one */ |
---|
3977 | } |
---|
3978 | s->mode = DRY; |
---|
3979 | case DRY: |
---|
3980 | FLUSH |
---|
3981 | if (s->read != s->write) |
---|
3982 | LEAVE |
---|
3983 | s->mode = DONEB; |
---|
3984 | case DONEB: |
---|
3985 | r = Z_STREAM_END; |
---|
3986 | LEAVE |
---|
3987 | case BADB: |
---|
3988 | r = Z_DATA_ERROR; |
---|
3989 | LEAVE |
---|
3990 | default: |
---|
3991 | r = Z_STREAM_ERROR; |
---|
3992 | LEAVE |
---|
3993 | } |
---|
3994 | } |
---|
3995 | |
---|
3996 | |
---|
3997 | int inflate_blocks_free(s, z, c) |
---|
3998 | inflate_blocks_statef *s; |
---|
3999 | z_streamp z; |
---|
4000 | uLongf *c; |
---|
4001 | { |
---|
4002 | inflate_blocks_reset(s, z, c); |
---|
4003 | ZFREE(z, s->window); |
---|
4004 | ZFREE(z, s); |
---|
4005 | Trace((stderr, "inflate: blocks freed\n")); |
---|
4006 | return Z_OK; |
---|
4007 | } |
---|
4008 | |
---|
4009 | |
---|
4010 | void inflate_set_dictionary(s, d, n) |
---|
4011 | inflate_blocks_statef *s; |
---|
4012 | const Bytef *d; |
---|
4013 | uInt n; |
---|
4014 | { |
---|
4015 | zmemcpy((charf *)s->window, d, n); |
---|
4016 | s->read = s->write = s->window + n; |
---|
4017 | } |
---|
4018 | |
---|
4019 | /* |
---|
4020 | * This subroutine adds the data at next_in/avail_in to the output history |
---|
4021 | * without performing any output. The output buffer must be "caught up"; |
---|
4022 | * i.e. no pending output (hence s->read equals s->write), and the state must |
---|
4023 | * be BLOCKS (i.e. we should be willing to see the start of a series of |
---|
4024 | * BLOCKS). On exit, the output will also be caught up, and the checksum |
---|
4025 | * will have been updated if need be. |
---|
4026 | */ |
---|
4027 | int inflate_addhistory(s, z) |
---|
4028 | inflate_blocks_statef *s; |
---|
4029 | z_stream *z; |
---|
4030 | { |
---|
4031 | uLong b; /* bit buffer */ /* NOT USED HERE */ |
---|
4032 | uInt k; /* bits in bit buffer */ /* NOT USED HERE */ |
---|
4033 | uInt t; /* temporary storage */ |
---|
4034 | Bytef *p; /* input data pointer */ |
---|
4035 | uInt n; /* bytes available there */ |
---|
4036 | Bytef *q; /* output window write pointer */ |
---|
4037 | uInt m; /* bytes to end of window or read pointer */ |
---|
4038 | |
---|
4039 | if (s->read != s->write) |
---|
4040 | return Z_STREAM_ERROR; |
---|
4041 | if (s->mode != TYPE) |
---|
4042 | return Z_DATA_ERROR; |
---|
4043 | |
---|
4044 | /* we're ready to rock */ |
---|
4045 | LOAD |
---|
4046 | /* while there is input ready, copy to output buffer, moving |
---|
4047 | * pointers as needed. |
---|
4048 | */ |
---|
4049 | while (n) { |
---|
4050 | t = n; /* how many to do */ |
---|
4051 | /* is there room until end of buffer? */ |
---|
4052 | if (t > m) t = m; |
---|
4053 | /* update check information */ |
---|
4054 | if (s->checkfn != Z_NULL) |
---|
4055 | s->check = (*s->checkfn)(s->check, q, t); |
---|
4056 | zmemcpy(q, p, t); |
---|
4057 | q += t; |
---|
4058 | p += t; |
---|
4059 | n -= t; |
---|
4060 | z->total_out += t; |
---|
4061 | s->read = q; /* drag read pointer forward */ |
---|
4062 | /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */ |
---|
4063 | if (q == s->end) { |
---|
4064 | s->read = q = s->window; |
---|
4065 | m = WAVAIL; |
---|
4066 | } |
---|
4067 | } |
---|
4068 | UPDATE |
---|
4069 | return Z_OK; |
---|
4070 | } |
---|
4071 | |
---|
4072 | |
---|
4073 | /* |
---|
4074 | * At the end of a Deflate-compressed PPP packet, we expect to have seen |
---|
4075 | * a `stored' block type value but not the (zero) length bytes. |
---|
4076 | */ |
---|
4077 | int inflate_packet_flush(s) |
---|
4078 | inflate_blocks_statef *s; |
---|
4079 | { |
---|
4080 | if (s->mode != LENS) |
---|
4081 | return Z_DATA_ERROR; |
---|
4082 | s->mode = TYPE; |
---|
4083 | return Z_OK; |
---|
4084 | } |
---|
4085 | /* --- infblock.c */ |
---|
4086 | |
---|
4087 | /* +++ inftrees.c */ |
---|
4088 | /* inftrees.c -- generate Huffman trees for efficient decoding |
---|
4089 | * Copyright (C) 1995-1996 Mark Adler |
---|
4090 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
4091 | */ |
---|
4092 | |
---|
4093 | /* #include "zutil.h" */ |
---|
4094 | /* #include "inftrees.h" */ |
---|
4095 | |
---|
4096 | char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler "; |
---|
4097 | /* |
---|
4098 | If you use the zlib library in a product, an acknowledgment is welcome |
---|
4099 | in the documentation of your product. If for some reason you cannot |
---|
4100 | include such an acknowledgment, I would appreciate that you keep this |
---|
4101 | copyright string in the executable of your product. |
---|
4102 | */ |
---|
4103 | |
---|
4104 | #ifndef NO_DUMMY_DECL |
---|
4105 | struct internal_state {int dummy;}; /* for buggy compilers */ |
---|
4106 | #endif |
---|
4107 | |
---|
4108 | /* simplify the use of the inflate_huft type with some defines */ |
---|
4109 | #define base more.Base |
---|
4110 | #define next more.Next |
---|
4111 | #define exop word.what.Exop |
---|
4112 | #define bits word.what.Bits |
---|
4113 | |
---|
4114 | |
---|
4115 | local int huft_build OF(( |
---|
4116 | uIntf *, /* code lengths in bits */ |
---|
4117 | uInt, /* number of codes */ |
---|
4118 | uInt, /* number of "simple" codes */ |
---|
4119 | const uIntf *, /* list of base values for non-simple codes */ |
---|
4120 | const uIntf *, /* list of extra bits for non-simple codes */ |
---|
4121 | inflate_huft * FAR*,/* result: starting table */ |
---|
4122 | uIntf *, /* maximum lookup bits (returns actual) */ |
---|
4123 | z_streamp )); /* for zalloc function */ |
---|
4124 | |
---|
4125 | local voidpf falloc OF(( |
---|
4126 | voidpf, /* opaque pointer (not used) */ |
---|
4127 | uInt, /* number of items */ |
---|
4128 | uInt)); /* size of item */ |
---|
4129 | |
---|
4130 | /* Tables for deflate from PKZIP's appnote.txt. */ |
---|
4131 | local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */ |
---|
4132 | 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, |
---|
4133 | 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; |
---|
4134 | /* see note #13 above about 258 */ |
---|
4135 | local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */ |
---|
4136 | 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, |
---|
4137 | 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */ |
---|
4138 | local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */ |
---|
4139 | 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, |
---|
4140 | 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, |
---|
4141 | 8193, 12289, 16385, 24577}; |
---|
4142 | local const uInt cpdext[30] = { /* Extra bits for distance codes */ |
---|
4143 | 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, |
---|
4144 | 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, |
---|
4145 | 12, 12, 13, 13}; |
---|
4146 | |
---|
4147 | /* |
---|
4148 | Huffman code decoding is performed using a multi-level table lookup. |
---|
4149 | The fastest way to decode is to simply build a lookup table whose |
---|
4150 | size is determined by the longest code. However, the time it takes |
---|
4151 | to build this table can also be a factor if the data being decoded |
---|
4152 | is not very long. The most common codes are necessarily the |
---|
4153 | shortest codes, so those codes dominate the decoding time, and hence |
---|
4154 | the speed. The idea is you can have a shorter table that decodes the |
---|
4155 | shorter, more probable codes, and then point to subsidiary tables for |
---|
4156 | the longer codes. The time it costs to decode the longer codes is |
---|
4157 | then traded against the time it takes to make longer tables. |
---|
4158 | |
---|
4159 | This results of this trade are in the variables lbits and dbits |
---|
4160 | below. lbits is the number of bits the first level table for literal/ |
---|
4161 | length codes can decode in one step, and dbits is the same thing for |
---|
4162 | the distance codes. Subsequent tables are also less than or equal to |
---|
4163 | those sizes. These values may be adjusted either when all of the |
---|
4164 | codes are shorter than that, in which case the longest code length in |
---|
4165 | bits is used, or when the shortest code is *longer* than the requested |
---|
4166 | table size, in which case the length of the shortest code in bits is |
---|
4167 | used. |
---|
4168 | |
---|
4169 | There are two different values for the two tables, since they code a |
---|
4170 | different number of possibilities each. The literal/length table |
---|
4171 | codes 286 possible values, or in a flat code, a little over eight |
---|
4172 | bits. The distance table codes 30 possible values, or a little less |
---|
4173 | than five bits, flat. The optimum values for speed end up being |
---|
4174 | about one bit more than those, so lbits is 8+1 and dbits is 5+1. |
---|
4175 | The optimum values may differ though from machine to machine, and |
---|
4176 | possibly even between compilers. Your mileage may vary. |
---|
4177 | */ |
---|
4178 | |
---|
4179 | |
---|
4180 | /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ |
---|
4181 | #define BMAX 15 /* maximum bit length of any code */ |
---|
4182 | #define N_MAX 288 /* maximum number of codes in any set */ |
---|
4183 | |
---|
4184 | #ifdef DEBUG_ZLIB |
---|
4185 | uInt inflate_hufts; |
---|
4186 | #endif |
---|
4187 | |
---|
4188 | local int huft_build(b, n, s, d, e, t, m, zs) |
---|
4189 | uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ |
---|
4190 | uInt n; /* number of codes (assumed <= N_MAX) */ |
---|
4191 | uInt s; /* number of simple-valued codes (0..s-1) */ |
---|
4192 | const uIntf *d; /* list of base values for non-simple codes */ |
---|
4193 | const uIntf *e; /* list of extra bits for non-simple codes */ |
---|
4194 | inflate_huft * FAR *t; /* result: starting table */ |
---|
4195 | uIntf *m; /* maximum lookup bits, returns actual */ |
---|
4196 | z_streamp zs; /* for zalloc function */ |
---|
4197 | /* Given a list of code lengths and a maximum table size, make a set of |
---|
4198 | tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR |
---|
4199 | if the given code set is incomplete (the tables are still built in this |
---|
4200 | case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of |
---|
4201 | lengths), or Z_MEM_ERROR if not enough memory. */ |
---|
4202 | { |
---|
4203 | |
---|
4204 | uInt a; /* counter for codes of length k */ |
---|
4205 | uInt c[BMAX+1]; /* bit length count table */ |
---|
4206 | uInt f; /* i repeats in table every f entries */ |
---|
4207 | int g; /* maximum code length */ |
---|
4208 | int h; /* table level */ |
---|
4209 | register uInt i; /* counter, current code */ |
---|
4210 | register uInt j; /* counter */ |
---|
4211 | register int k; /* number of bits in current code */ |
---|
4212 | int l; /* bits per table (returned in m) */ |
---|
4213 | register uIntf *p; /* pointer into c[], b[], or v[] */ |
---|
4214 | inflate_huft *q; /* points to current table */ |
---|
4215 | struct inflate_huft_s r; /* table entry for structure assignment */ |
---|
4216 | inflate_huft *u[BMAX]; /* table stack */ |
---|
4217 | uInt v[N_MAX]; /* values in order of bit length */ |
---|
4218 | register int w; /* bits before this table == (l * h) */ |
---|
4219 | uInt x[BMAX+1]; /* bit offsets, then code stack */ |
---|
4220 | uIntf *xp; /* pointer into x */ |
---|
4221 | int y; /* number of dummy codes added */ |
---|
4222 | uInt z; /* number of entries in current table */ |
---|
4223 | |
---|
4224 | |
---|
4225 | /* Generate counts for each bit length */ |
---|
4226 | p = c; |
---|
4227 | #define C0 *p++ = 0; |
---|
4228 | #define C2 C0 C0 C0 C0 |
---|
4229 | #define C4 C2 C2 C2 C2 |
---|
4230 | C4 /* clear c[]--assume BMAX+1 is 16 */ |
---|
4231 | p = b; i = n; |
---|
4232 | do { |
---|
4233 | c[*p++]++; /* assume all entries <= BMAX */ |
---|
4234 | } while (--i); |
---|
4235 | if (c[0] == n) /* null input--all zero length codes */ |
---|
4236 | { |
---|
4237 | *t = (inflate_huft *)Z_NULL; |
---|
4238 | *m = 0; |
---|
4239 | return Z_OK; |
---|
4240 | } |
---|
4241 | |
---|
4242 | |
---|
4243 | /* Find minimum and maximum length, bound *m by those */ |
---|
4244 | l = *m; |
---|
4245 | for (j = 1; j <= BMAX; j++) |
---|
4246 | if (c[j]) |
---|
4247 | break; |
---|
4248 | k = j; /* minimum code length */ |
---|
4249 | if ((uInt)l < j) |
---|
4250 | l = j; |
---|
4251 | for (i = BMAX; i; i--) |
---|
4252 | if (c[i]) |
---|
4253 | break; |
---|
4254 | g = i; /* maximum code length */ |
---|
4255 | if ((uInt)l > i) |
---|
4256 | l = i; |
---|
4257 | *m = l; |
---|
4258 | |
---|
4259 | |
---|
4260 | /* Adjust last length count to fill out codes, if needed */ |
---|
4261 | for (y = 1 << j; j < i; j++, y <<= 1) |
---|
4262 | if ((y -= c[j]) < 0) |
---|
4263 | return Z_DATA_ERROR; |
---|
4264 | if ((y -= c[i]) < 0) |
---|
4265 | return Z_DATA_ERROR; |
---|
4266 | c[i] += y; |
---|
4267 | |
---|
4268 | |
---|
4269 | /* Generate starting offsets into the value table for each length */ |
---|
4270 | x[1] = j = 0; |
---|
4271 | p = c + 1; xp = x + 2; |
---|
4272 | while (--i) { /* note that i == g from above */ |
---|
4273 | *xp++ = (j += *p++); |
---|
4274 | } |
---|
4275 | |
---|
4276 | |
---|
4277 | /* Make a table of values in order of bit lengths */ |
---|
4278 | p = b; i = 0; |
---|
4279 | do { |
---|
4280 | if ((j = *p++) != 0) |
---|
4281 | v[x[j]++] = i; |
---|
4282 | } while (++i < n); |
---|
4283 | n = x[g]; /* set n to length of v */ |
---|
4284 | |
---|
4285 | |
---|
4286 | /* Generate the Huffman codes and for each, make the table entries */ |
---|
4287 | x[0] = i = 0; /* first Huffman code is zero */ |
---|
4288 | p = v; /* grab values in bit order */ |
---|
4289 | h = -1; /* no tables yet--level -1 */ |
---|
4290 | w = -l; /* bits decoded == (l * h) */ |
---|
4291 | u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ |
---|
4292 | q = (inflate_huft *)Z_NULL; /* ditto */ |
---|
4293 | z = 0; /* ditto */ |
---|
4294 | |
---|
4295 | /* go through the bit lengths (k already is bits in shortest code) */ |
---|
4296 | for (; k <= g; k++) |
---|
4297 | { |
---|
4298 | a = c[k]; |
---|
4299 | while (a--) |
---|
4300 | { |
---|
4301 | /* here i is the Huffman code of length k bits for value *p */ |
---|
4302 | /* make tables up to required level */ |
---|
4303 | while (k > w + l) |
---|
4304 | { |
---|
4305 | h++; |
---|
4306 | w += l; /* previous table always l bits */ |
---|
4307 | |
---|
4308 | /* compute minimum size table less than or equal to l bits */ |
---|
4309 | z = g - w; |
---|
4310 | z = z > (uInt)l ? l : z; /* table size upper limit */ |
---|
4311 | if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ |
---|
4312 | { /* too few codes for k-w bit table */ |
---|
4313 | f -= a + 1; /* deduct codes from patterns left */ |
---|
4314 | xp = c + k; |
---|
4315 | if (j < z) |
---|
4316 | while (++j < z) /* try smaller tables up to z bits */ |
---|
4317 | { |
---|
4318 | if ((f <<= 1) <= *++xp) |
---|
4319 | break; /* enough codes to use up j bits */ |
---|
4320 | f -= *xp; /* else deduct codes from patterns */ |
---|
4321 | } |
---|
4322 | } |
---|
4323 | z = 1 << j; /* table entries for j-bit table */ |
---|
4324 | |
---|
4325 | /* allocate and link in new table */ |
---|
4326 | if ((q = (inflate_huft *)ZALLOC |
---|
4327 | (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) |
---|
4328 | { |
---|
4329 | if (h) |
---|
4330 | inflate_trees_free(u[0], zs); |
---|
4331 | return Z_MEM_ERROR; /* not enough memory */ |
---|
4332 | } |
---|
4333 | #ifdef DEBUG_ZLIB |
---|
4334 | inflate_hufts += z + 1; |
---|
4335 | #endif |
---|
4336 | *t = q + 1; /* link to list for huft_free() */ |
---|
4337 | *(t = &(q->next)) = Z_NULL; |
---|
4338 | u[h] = ++q; /* table starts after link */ |
---|
4339 | |
---|
4340 | /* connect to last table, if there is one */ |
---|
4341 | if (h) |
---|
4342 | { |
---|
4343 | x[h] = i; /* save pattern for backing up */ |
---|
4344 | r.bits = (Byte)l; /* bits to dump before this table */ |
---|
4345 | r.exop = (Byte)j; /* bits in this table */ |
---|
4346 | r.next = q; /* pointer to this table */ |
---|
4347 | j = i >> (w - l); /* (get around Turbo C bug) */ |
---|
4348 | u[h-1][j] = r; /* connect to last table */ |
---|
4349 | } |
---|
4350 | } |
---|
4351 | |
---|
4352 | /* set up table entry in r */ |
---|
4353 | r.bits = (Byte)(k - w); |
---|
4354 | if (p >= v + n) |
---|
4355 | r.exop = 128 + 64; /* out of values--invalid code */ |
---|
4356 | else if (*p < s) |
---|
4357 | { |
---|
4358 | r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ |
---|
4359 | r.base = *p++; /* simple code is just the value */ |
---|
4360 | } |
---|
4361 | else |
---|
4362 | { |
---|
4363 | r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ |
---|
4364 | r.base = d[*p++ - s]; |
---|
4365 | } |
---|
4366 | |
---|
4367 | /* fill code-like entries with r */ |
---|
4368 | f = 1 << (k - w); |
---|
4369 | for (j = i >> w; j < z; j += f) |
---|
4370 | q[j] = r; |
---|
4371 | |
---|
4372 | /* backwards increment the k-bit code i */ |
---|
4373 | for (j = 1 << (k - 1); i & j; j >>= 1) |
---|
4374 | i ^= j; |
---|
4375 | i ^= j; |
---|
4376 | |
---|
4377 | /* backup over finished tables */ |
---|
4378 | while ((i & ((1 << w) - 1)) != x[h]) |
---|
4379 | { |
---|
4380 | h--; /* don't need to update q */ |
---|
4381 | w -= l; |
---|
4382 | } |
---|
4383 | } |
---|
4384 | } |
---|
4385 | |
---|
4386 | |
---|
4387 | /* Return Z_BUF_ERROR if we were given an incomplete table */ |
---|
4388 | return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; |
---|
4389 | } |
---|
4390 | |
---|
4391 | |
---|
4392 | int inflate_trees_bits(c, bb, tb, z) |
---|
4393 | uIntf *c; /* 19 code lengths */ |
---|
4394 | uIntf *bb; /* bits tree desired/actual depth */ |
---|
4395 | inflate_huft * FAR *tb; /* bits tree result */ |
---|
4396 | z_streamp z; /* for zfree function */ |
---|
4397 | { |
---|
4398 | int r; |
---|
4399 | |
---|
4400 | r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); |
---|
4401 | if (r == Z_DATA_ERROR) |
---|
4402 | z->msg = (char*)"oversubscribed dynamic bit lengths tree"; |
---|
4403 | else if (r == Z_BUF_ERROR || *bb == 0) |
---|
4404 | { |
---|
4405 | inflate_trees_free(*tb, z); |
---|
4406 | z->msg = (char*)"incomplete dynamic bit lengths tree"; |
---|
4407 | r = Z_DATA_ERROR; |
---|
4408 | } |
---|
4409 | return r; |
---|
4410 | } |
---|
4411 | |
---|
4412 | |
---|
4413 | int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) |
---|
4414 | uInt nl; /* number of literal/length codes */ |
---|
4415 | uInt nd; /* number of distance codes */ |
---|
4416 | uIntf *c; /* that many (total) code lengths */ |
---|
4417 | uIntf *bl; /* literal desired/actual bit depth */ |
---|
4418 | uIntf *bd; /* distance desired/actual bit depth */ |
---|
4419 | inflate_huft * FAR *tl; /* literal/length tree result */ |
---|
4420 | inflate_huft * FAR *td; /* distance tree result */ |
---|
4421 | z_streamp z; /* for zfree function */ |
---|
4422 | { |
---|
4423 | int r; |
---|
4424 | |
---|
4425 | /* build literal/length tree */ |
---|
4426 | r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); |
---|
4427 | if (r != Z_OK || *bl == 0) |
---|
4428 | { |
---|
4429 | if (r == Z_DATA_ERROR) |
---|
4430 | z->msg = (char*)"oversubscribed literal/length tree"; |
---|
4431 | else if (r != Z_MEM_ERROR) |
---|
4432 | { |
---|
4433 | inflate_trees_free(*tl, z); |
---|
4434 | z->msg = (char*)"incomplete literal/length tree"; |
---|
4435 | r = Z_DATA_ERROR; |
---|
4436 | } |
---|
4437 | return r; |
---|
4438 | } |
---|
4439 | |
---|
4440 | /* build distance tree */ |
---|
4441 | r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); |
---|
4442 | if (r != Z_OK || (*bd == 0 && nl > 257)) |
---|
4443 | { |
---|
4444 | if (r == Z_DATA_ERROR) |
---|
4445 | z->msg = (char*)"oversubscribed distance tree"; |
---|
4446 | else if (r == Z_BUF_ERROR) { |
---|
4447 | #ifdef PKZIP_BUG_WORKAROUND |
---|
4448 | r = Z_OK; |
---|
4449 | } |
---|
4450 | #else |
---|
4451 | inflate_trees_free(*td, z); |
---|
4452 | z->msg = (char*)"incomplete distance tree"; |
---|
4453 | r = Z_DATA_ERROR; |
---|
4454 | } |
---|
4455 | else if (r != Z_MEM_ERROR) |
---|
4456 | { |
---|
4457 | z->msg = (char*)"empty distance tree with lengths"; |
---|
4458 | r = Z_DATA_ERROR; |
---|
4459 | } |
---|
4460 | inflate_trees_free(*tl, z); |
---|
4461 | return r; |
---|
4462 | #endif |
---|
4463 | } |
---|
4464 | |
---|
4465 | /* done */ |
---|
4466 | return Z_OK; |
---|
4467 | } |
---|
4468 | |
---|
4469 | |
---|
4470 | /* build fixed tables only once--keep them here */ |
---|
4471 | local int fixed_built = 0; |
---|
4472 | #define FIXEDH 530 /* number of hufts used by fixed tables */ |
---|
4473 | local inflate_huft fixed_mem[FIXEDH]; |
---|
4474 | local uInt fixed_bl; |
---|
4475 | local uInt fixed_bd; |
---|
4476 | local inflate_huft *fixed_tl; |
---|
4477 | local inflate_huft *fixed_td; |
---|
4478 | |
---|
4479 | |
---|
4480 | local voidpf falloc(q, n, s) |
---|
4481 | voidpf q; /* opaque pointer */ |
---|
4482 | uInt n; /* number of items */ |
---|
4483 | uInt s; /* size of item */ |
---|
4484 | { |
---|
4485 | Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, |
---|
4486 | "inflate_trees falloc overflow"); |
---|
4487 | *(intf *)q -= n+s-s; /* s-s to avoid warning */ |
---|
4488 | return (voidpf)(fixed_mem + *(intf *)q); |
---|
4489 | } |
---|
4490 | |
---|
4491 | |
---|
4492 | int inflate_trees_fixed(bl, bd, tl, td) |
---|
4493 | uIntf *bl; /* literal desired/actual bit depth */ |
---|
4494 | uIntf *bd; /* distance desired/actual bit depth */ |
---|
4495 | inflate_huft * FAR *tl; /* literal/length tree result */ |
---|
4496 | inflate_huft * FAR *td; /* distance tree result */ |
---|
4497 | { |
---|
4498 | /* build fixed tables if not already (multiple overlapped executions ok) */ |
---|
4499 | if (!fixed_built) |
---|
4500 | { |
---|
4501 | int k; /* temporary variable */ |
---|
4502 | unsigned c[288]; /* length list for huft_build */ |
---|
4503 | z_stream z; /* for falloc function */ |
---|
4504 | int f = FIXEDH; /* number of hufts left in fixed_mem */ |
---|
4505 | |
---|
4506 | /* set up fake z_stream for memory routines */ |
---|
4507 | z.zalloc = falloc; |
---|
4508 | z.zfree = Z_NULL; |
---|
4509 | z.opaque = (voidpf)&f; |
---|
4510 | |
---|
4511 | /* literal table */ |
---|
4512 | for (k = 0; k < 144; k++) |
---|
4513 | c[k] = 8; |
---|
4514 | for (; k < 256; k++) |
---|
4515 | c[k] = 9; |
---|
4516 | for (; k < 280; k++) |
---|
4517 | c[k] = 7; |
---|
4518 | for (; k < 288; k++) |
---|
4519 | c[k] = 8; |
---|
4520 | fixed_bl = 7; |
---|
4521 | huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); |
---|
4522 | |
---|
4523 | /* distance table */ |
---|
4524 | for (k = 0; k < 30; k++) |
---|
4525 | c[k] = 5; |
---|
4526 | fixed_bd = 5; |
---|
4527 | huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); |
---|
4528 | |
---|
4529 | /* done */ |
---|
4530 | Assert(f == 0, "invalid build of fixed tables"); |
---|
4531 | fixed_built = 1; |
---|
4532 | } |
---|
4533 | *bl = fixed_bl; |
---|
4534 | *bd = fixed_bd; |
---|
4535 | *tl = fixed_tl; |
---|
4536 | *td = fixed_td; |
---|
4537 | return Z_OK; |
---|
4538 | } |
---|
4539 | |
---|
4540 | |
---|
4541 | int inflate_trees_free(t, z) |
---|
4542 | inflate_huft *t; /* table to free */ |
---|
4543 | z_streamp z; /* for zfree function */ |
---|
4544 | /* Free the malloc'ed tables built by huft_build(), which makes a linked |
---|
4545 | list of the tables it made, with the links in a dummy first entry of |
---|
4546 | each table. */ |
---|
4547 | { |
---|
4548 | register inflate_huft *p, *q, *r; |
---|
4549 | |
---|
4550 | /* Reverse linked list */ |
---|
4551 | p = Z_NULL; |
---|
4552 | q = t; |
---|
4553 | while (q != Z_NULL) |
---|
4554 | { |
---|
4555 | r = (q - 1)->next; |
---|
4556 | (q - 1)->next = p; |
---|
4557 | p = q; |
---|
4558 | q = r; |
---|
4559 | } |
---|
4560 | /* Go through linked list, freeing from the malloced (t[-1]) address. */ |
---|
4561 | while (p != Z_NULL) |
---|
4562 | { |
---|
4563 | q = (--p)->next; |
---|
4564 | ZFREE(z,p); |
---|
4565 | p = q; |
---|
4566 | } |
---|
4567 | return Z_OK; |
---|
4568 | } |
---|
4569 | /* --- inftrees.c */ |
---|
4570 | |
---|
4571 | /* +++ infcodes.c */ |
---|
4572 | /* infcodes.c -- process literals and length/distance pairs |
---|
4573 | * Copyright (C) 1995-1996 Mark Adler |
---|
4574 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
4575 | */ |
---|
4576 | |
---|
4577 | /* #include "zutil.h" */ |
---|
4578 | /* #include "inftrees.h" */ |
---|
4579 | /* #include "infblock.h" */ |
---|
4580 | /* #include "infcodes.h" */ |
---|
4581 | /* #include "infutil.h" */ |
---|
4582 | |
---|
4583 | /* +++ inffast.h */ |
---|
4584 | /* inffast.h -- header to use inffast.c |
---|
4585 | * Copyright (C) 1995-1996 Mark Adler |
---|
4586 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
4587 | */ |
---|
4588 | |
---|
4589 | /* WARNING: this file should *not* be used by applications. It is |
---|
4590 | part of the implementation of the compression library and is |
---|
4591 | subject to change. Applications should only use zlib.h. |
---|
4592 | */ |
---|
4593 | |
---|
4594 | extern int inflate_fast OF(( |
---|
4595 | uInt, |
---|
4596 | uInt, |
---|
4597 | inflate_huft *, |
---|
4598 | inflate_huft *, |
---|
4599 | inflate_blocks_statef *, |
---|
4600 | z_streamp )); |
---|
4601 | /* --- inffast.h */ |
---|
4602 | |
---|
4603 | /* simplify the use of the inflate_huft type with some defines */ |
---|
4604 | #define base more.Base |
---|
4605 | #define next more.Next |
---|
4606 | #define exop word.what.Exop |
---|
4607 | #define bits word.what.Bits |
---|
4608 | |
---|
4609 | /* inflate codes private state */ |
---|
4610 | struct inflate_codes_state { |
---|
4611 | |
---|
4612 | /* mode */ |
---|
4613 | enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ |
---|
4614 | START, /* x: set up for LEN */ |
---|
4615 | LEN, /* i: get length/literal/eob next */ |
---|
4616 | LENEXT, /* i: getting length extra (have base) */ |
---|
4617 | DIST, /* i: get distance next */ |
---|
4618 | DISTEXT, /* i: getting distance extra */ |
---|
4619 | COPY, /* o: copying bytes in window, waiting for space */ |
---|
4620 | LIT, /* o: got literal, waiting for output space */ |
---|
4621 | WASH, /* o: got eob, possibly still output waiting */ |
---|
4622 | END, /* x: got eob and all data flushed */ |
---|
4623 | BADCODE} /* x: got error */ |
---|
4624 | mode; /* current inflate_codes mode */ |
---|
4625 | |
---|
4626 | /* mode dependent information */ |
---|
4627 | uInt len; |
---|
4628 | union { |
---|
4629 | struct { |
---|
4630 | inflate_huft *tree; /* pointer into tree */ |
---|
4631 | uInt need; /* bits needed */ |
---|
4632 | } code; /* if LEN or DIST, where in tree */ |
---|
4633 | uInt lit; /* if LIT, literal */ |
---|
4634 | struct { |
---|
4635 | uInt get; /* bits to get for extra */ |
---|
4636 | uInt dist; /* distance back to copy from */ |
---|
4637 | } copy; /* if EXT or COPY, where and how much */ |
---|
4638 | } sub; /* submode */ |
---|
4639 | |
---|
4640 | /* mode independent information */ |
---|
4641 | Byte lbits; /* ltree bits decoded per branch */ |
---|
4642 | Byte dbits; /* dtree bits decoder per branch */ |
---|
4643 | inflate_huft *ltree; /* literal/length/eob tree */ |
---|
4644 | inflate_huft *dtree; /* distance tree */ |
---|
4645 | |
---|
4646 | }; |
---|
4647 | |
---|
4648 | |
---|
4649 | inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) |
---|
4650 | uInt bl, bd; |
---|
4651 | inflate_huft *tl; |
---|
4652 | inflate_huft *td; /* need separate declaration for Borland C++ */ |
---|
4653 | z_streamp z; |
---|
4654 | { |
---|
4655 | inflate_codes_statef *c; |
---|
4656 | |
---|
4657 | if ((c = (inflate_codes_statef *) |
---|
4658 | ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) |
---|
4659 | { |
---|
4660 | c->mode = START; |
---|
4661 | c->lbits = (Byte)bl; |
---|
4662 | c->dbits = (Byte)bd; |
---|
4663 | c->ltree = tl; |
---|
4664 | c->dtree = td; |
---|
4665 | Tracev((stderr, "inflate: codes new\n")); |
---|
4666 | } |
---|
4667 | return c; |
---|
4668 | } |
---|
4669 | |
---|
4670 | |
---|
4671 | int inflate_codes(s, z, r) |
---|
4672 | inflate_blocks_statef *s; |
---|
4673 | z_streamp z; |
---|
4674 | int r; |
---|
4675 | { |
---|
4676 | uInt j; /* temporary storage */ |
---|
4677 | inflate_huft *t; /* temporary pointer */ |
---|
4678 | uInt e; /* extra bits or operation */ |
---|
4679 | uLong b; /* bit buffer */ |
---|
4680 | uInt k; /* bits in bit buffer */ |
---|
4681 | Bytef *p; /* input data pointer */ |
---|
4682 | uInt n; /* bytes available there */ |
---|
4683 | Bytef *q; /* output window write pointer */ |
---|
4684 | uInt m; /* bytes to end of window or read pointer */ |
---|
4685 | Bytef *f; /* pointer to copy strings from */ |
---|
4686 | inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ |
---|
4687 | |
---|
4688 | /* copy input/output information to locals (UPDATE macro restores) */ |
---|
4689 | LOAD |
---|
4690 | |
---|
4691 | /* process input and output based on current state */ |
---|
4692 | while (1) switch (c->mode) |
---|
4693 | { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ |
---|
4694 | case START: /* x: set up for LEN */ |
---|
4695 | #ifndef SLOW |
---|
4696 | if (m >= 258 && n >= 10) |
---|
4697 | { |
---|
4698 | UPDATE |
---|
4699 | r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); |
---|
4700 | LOAD |
---|
4701 | if (r != Z_OK) |
---|
4702 | { |
---|
4703 | c->mode = r == Z_STREAM_END ? WASH : BADCODE; |
---|
4704 | break; |
---|
4705 | } |
---|
4706 | } |
---|
4707 | #endif /* !SLOW */ |
---|
4708 | c->sub.code.need = c->lbits; |
---|
4709 | c->sub.code.tree = c->ltree; |
---|
4710 | c->mode = LEN; |
---|
4711 | case LEN: /* i: get length/literal/eob next */ |
---|
4712 | j = c->sub.code.need; |
---|
4713 | NEEDBITS(j) |
---|
4714 | t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); |
---|
4715 | DUMPBITS(t->bits) |
---|
4716 | e = (uInt)(t->exop); |
---|
4717 | if (e == 0) /* literal */ |
---|
4718 | { |
---|
4719 | c->sub.lit = t->base; |
---|
4720 | Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? |
---|
4721 | "inflate: literal '%c'\n" : |
---|
4722 | "inflate: literal 0x%02x\n", t->base)); |
---|
4723 | c->mode = LIT; |
---|
4724 | break; |
---|
4725 | } |
---|
4726 | if (e & 16) /* length */ |
---|
4727 | { |
---|
4728 | c->sub.copy.get = e & 15; |
---|
4729 | c->len = t->base; |
---|
4730 | c->mode = LENEXT; |
---|
4731 | break; |
---|
4732 | } |
---|
4733 | if ((e & 64) == 0) /* next table */ |
---|
4734 | { |
---|
4735 | c->sub.code.need = e; |
---|
4736 | c->sub.code.tree = t->next; |
---|
4737 | break; |
---|
4738 | } |
---|
4739 | if (e & 32) /* end of block */ |
---|
4740 | { |
---|
4741 | Tracevv((stderr, "inflate: end of block\n")); |
---|
4742 | c->mode = WASH; |
---|
4743 | break; |
---|
4744 | } |
---|
4745 | c->mode = BADCODE; /* invalid code */ |
---|
4746 | z->msg = (char*)"invalid literal/length code"; |
---|
4747 | r = Z_DATA_ERROR; |
---|
4748 | LEAVE |
---|
4749 | case LENEXT: /* i: getting length extra (have base) */ |
---|
4750 | j = c->sub.copy.get; |
---|
4751 | NEEDBITS(j) |
---|
4752 | c->len += (uInt)b & inflate_mask[j]; |
---|
4753 | DUMPBITS(j) |
---|
4754 | c->sub.code.need = c->dbits; |
---|
4755 | c->sub.code.tree = c->dtree; |
---|
4756 | Tracevv((stderr, "inflate: length %u\n", c->len)); |
---|
4757 | c->mode = DIST; |
---|
4758 | case DIST: /* i: get distance next */ |
---|
4759 | j = c->sub.code.need; |
---|
4760 | NEEDBITS(j) |
---|
4761 | t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); |
---|
4762 | DUMPBITS(t->bits) |
---|
4763 | e = (uInt)(t->exop); |
---|
4764 | if (e & 16) /* distance */ |
---|
4765 | { |
---|
4766 | c->sub.copy.get = e & 15; |
---|
4767 | c->sub.copy.dist = t->base; |
---|
4768 | c->mode = DISTEXT; |
---|
4769 | break; |
---|
4770 | } |
---|
4771 | if ((e & 64) == 0) /* next table */ |
---|
4772 | { |
---|
4773 | c->sub.code.need = e; |
---|
4774 | c->sub.code.tree = t->next; |
---|
4775 | break; |
---|
4776 | } |
---|
4777 | c->mode = BADCODE; /* invalid code */ |
---|
4778 | z->msg = (char*)"invalid distance code"; |
---|
4779 | r = Z_DATA_ERROR; |
---|
4780 | LEAVE |
---|
4781 | case DISTEXT: /* i: getting distance extra */ |
---|
4782 | j = c->sub.copy.get; |
---|
4783 | NEEDBITS(j) |
---|
4784 | c->sub.copy.dist += (uInt)b & inflate_mask[j]; |
---|
4785 | DUMPBITS(j) |
---|
4786 | Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); |
---|
4787 | c->mode = COPY; |
---|
4788 | case COPY: /* o: copying bytes in window, waiting for space */ |
---|
4789 | #ifndef __TURBOC__ /* Turbo C bug for following expression */ |
---|
4790 | f = (uInt)(q - s->window) < c->sub.copy.dist ? |
---|
4791 | s->end - (c->sub.copy.dist - (q - s->window)) : |
---|
4792 | q - c->sub.copy.dist; |
---|
4793 | #else |
---|
4794 | f = q - c->sub.copy.dist; |
---|
4795 | if ((uInt)(q - s->window) < c->sub.copy.dist) |
---|
4796 | f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); |
---|
4797 | #endif |
---|
4798 | while (c->len) |
---|
4799 | { |
---|
4800 | NEEDOUT |
---|
4801 | OUTBYTE(*f++) |
---|
4802 | if (f == s->end) |
---|
4803 | f = s->window; |
---|
4804 | c->len--; |
---|
4805 | } |
---|
4806 | c->mode = START; |
---|
4807 | break; |
---|
4808 | case LIT: /* o: got literal, waiting for output space */ |
---|
4809 | NEEDOUT |
---|
4810 | OUTBYTE(c->sub.lit) |
---|
4811 | c->mode = START; |
---|
4812 | break; |
---|
4813 | case WASH: /* o: got eob, possibly more output */ |
---|
4814 | FLUSH |
---|
4815 | if (s->read != s->write) |
---|
4816 | LEAVE |
---|
4817 | c->mode = END; |
---|
4818 | case END: |
---|
4819 | r = Z_STREAM_END; |
---|
4820 | LEAVE |
---|
4821 | case BADCODE: /* x: got error */ |
---|
4822 | r = Z_DATA_ERROR; |
---|
4823 | LEAVE |
---|
4824 | default: |
---|
4825 | r = Z_STREAM_ERROR; |
---|
4826 | LEAVE |
---|
4827 | } |
---|
4828 | } |
---|
4829 | |
---|
4830 | |
---|
4831 | void inflate_codes_free(c, z) |
---|
4832 | inflate_codes_statef *c; |
---|
4833 | z_streamp z; |
---|
4834 | { |
---|
4835 | ZFREE(z, c); |
---|
4836 | Tracev((stderr, "inflate: codes free\n")); |
---|
4837 | } |
---|
4838 | /* --- infcodes.c */ |
---|
4839 | |
---|
4840 | /* +++ infutil.c */ |
---|
4841 | /* inflate_util.c -- data and routines common to blocks and codes |
---|
4842 | * Copyright (C) 1995-1996 Mark Adler |
---|
4843 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
4844 | */ |
---|
4845 | |
---|
4846 | /* #include "zutil.h" */ |
---|
4847 | /* #include "infblock.h" */ |
---|
4848 | /* #include "inftrees.h" */ |
---|
4849 | /* #include "infcodes.h" */ |
---|
4850 | /* #include "infutil.h" */ |
---|
4851 | |
---|
4852 | #ifndef NO_DUMMY_DECL |
---|
4853 | struct inflate_codes_state {int dummy;}; /* for buggy compilers */ |
---|
4854 | #endif |
---|
4855 | |
---|
4856 | /* And'ing with mask[n] masks the lower n bits */ |
---|
4857 | uInt inflate_mask[17] = { |
---|
4858 | 0x0000, |
---|
4859 | 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, |
---|
4860 | 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff |
---|
4861 | }; |
---|
4862 | |
---|
4863 | |
---|
4864 | /* copy as much as possible from the sliding window to the output area */ |
---|
4865 | int inflate_flush(s, z, r) |
---|
4866 | inflate_blocks_statef *s; |
---|
4867 | z_streamp z; |
---|
4868 | int r; |
---|
4869 | { |
---|
4870 | uInt n; |
---|
4871 | Bytef *p; |
---|
4872 | Bytef *q; |
---|
4873 | |
---|
4874 | /* local copies of source and destination pointers */ |
---|
4875 | p = z->next_out; |
---|
4876 | q = s->read; |
---|
4877 | |
---|
4878 | /* compute number of bytes to copy as far as end of window */ |
---|
4879 | n = (uInt)((q <= s->write ? s->write : s->end) - q); |
---|
4880 | if (n > z->avail_out) n = z->avail_out; |
---|
4881 | if (n && r == Z_BUF_ERROR) r = Z_OK; |
---|
4882 | |
---|
4883 | /* update counters */ |
---|
4884 | z->avail_out -= n; |
---|
4885 | z->total_out += n; |
---|
4886 | |
---|
4887 | /* update check information */ |
---|
4888 | if (s->checkfn != Z_NULL) |
---|
4889 | z->adler = s->check = (*s->checkfn)(s->check, q, n); |
---|
4890 | |
---|
4891 | /* copy as far as end of window */ |
---|
4892 | if (p != Z_NULL) { |
---|
4893 | zmemcpy(p, q, n); |
---|
4894 | p += n; |
---|
4895 | } |
---|
4896 | q += n; |
---|
4897 | |
---|
4898 | /* see if more to copy at beginning of window */ |
---|
4899 | if (q == s->end) |
---|
4900 | { |
---|
4901 | /* wrap pointers */ |
---|
4902 | q = s->window; |
---|
4903 | if (s->write == s->end) |
---|
4904 | s->write = s->window; |
---|
4905 | |
---|
4906 | /* compute bytes to copy */ |
---|
4907 | n = (uInt)(s->write - q); |
---|
4908 | if (n > z->avail_out) n = z->avail_out; |
---|
4909 | if (n && r == Z_BUF_ERROR) r = Z_OK; |
---|
4910 | |
---|
4911 | /* update counters */ |
---|
4912 | z->avail_out -= n; |
---|
4913 | z->total_out += n; |
---|
4914 | |
---|
4915 | /* update check information */ |
---|
4916 | if (s->checkfn != Z_NULL) |
---|
4917 | z->adler = s->check = (*s->checkfn)(s->check, q, n); |
---|
4918 | |
---|
4919 | /* copy */ |
---|
4920 | if (p != Z_NULL) { |
---|
4921 | zmemcpy(p, q, n); |
---|
4922 | p += n; |
---|
4923 | } |
---|
4924 | q += n; |
---|
4925 | } |
---|
4926 | |
---|
4927 | /* update pointers */ |
---|
4928 | z->next_out = p; |
---|
4929 | s->read = q; |
---|
4930 | |
---|
4931 | /* done */ |
---|
4932 | return r; |
---|
4933 | } |
---|
4934 | /* --- infutil.c */ |
---|
4935 | |
---|
4936 | /* +++ inffast.c */ |
---|
4937 | /* inffast.c -- process literals and length/distance pairs fast |
---|
4938 | * Copyright (C) 1995-1996 Mark Adler |
---|
4939 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
4940 | */ |
---|
4941 | |
---|
4942 | /* #include "zutil.h" */ |
---|
4943 | /* #include "inftrees.h" */ |
---|
4944 | /* #include "infblock.h" */ |
---|
4945 | /* #include "infcodes.h" */ |
---|
4946 | /* #include "infutil.h" */ |
---|
4947 | /* #include "inffast.h" */ |
---|
4948 | |
---|
4949 | #ifndef NO_DUMMY_DECL |
---|
4950 | struct inflate_codes_state {int dummy;}; /* for buggy compilers */ |
---|
4951 | #endif |
---|
4952 | |
---|
4953 | /* simplify the use of the inflate_huft type with some defines */ |
---|
4954 | #define base more.Base |
---|
4955 | #define next more.Next |
---|
4956 | #define exop word.what.Exop |
---|
4957 | #define bits word.what.Bits |
---|
4958 | |
---|
4959 | /* macros for bit input with no checking and for returning unused bytes */ |
---|
4960 | #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} |
---|
4961 | #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} |
---|
4962 | |
---|
4963 | /* Called with number of bytes left to write in window at least 258 |
---|
4964 | (the maximum string length) and number of input bytes available |
---|
4965 | at least ten. The ten bytes are six bytes for the longest length/ |
---|
4966 | distance pair plus four bytes for overloading the bit buffer. */ |
---|
4967 | |
---|
4968 | int inflate_fast(bl, bd, tl, td, s, z) |
---|
4969 | uInt bl, bd; |
---|
4970 | inflate_huft *tl; |
---|
4971 | inflate_huft *td; /* need separate declaration for Borland C++ */ |
---|
4972 | inflate_blocks_statef *s; |
---|
4973 | z_streamp z; |
---|
4974 | { |
---|
4975 | inflate_huft *t; /* temporary pointer */ |
---|
4976 | uInt e; /* extra bits or operation */ |
---|
4977 | uLong b; /* bit buffer */ |
---|
4978 | uInt k; /* bits in bit buffer */ |
---|
4979 | Bytef *p; /* input data pointer */ |
---|
4980 | uInt n; /* bytes available there */ |
---|
4981 | Bytef *q; /* output window write pointer */ |
---|
4982 | uInt m; /* bytes to end of window or read pointer */ |
---|
4983 | uInt ml; /* mask for literal/length tree */ |
---|
4984 | uInt md; /* mask for distance tree */ |
---|
4985 | uInt c; /* bytes to copy */ |
---|
4986 | uInt d; /* distance back to copy from */ |
---|
4987 | Bytef *r; /* copy source pointer */ |
---|
4988 | |
---|
4989 | /* load input, output, bit values */ |
---|
4990 | LOAD |
---|
4991 | |
---|
4992 | /* initialize masks */ |
---|
4993 | ml = inflate_mask[bl]; |
---|
4994 | md = inflate_mask[bd]; |
---|
4995 | |
---|
4996 | /* do until not enough input or output space for fast loop */ |
---|
4997 | do { /* assume called with m >= 258 && n >= 10 */ |
---|
4998 | /* get literal/length code */ |
---|
4999 | GRABBITS(20) /* max bits for literal/length code */ |
---|
5000 | if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) |
---|
5001 | { |
---|
5002 | DUMPBITS(t->bits) |
---|
5003 | Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? |
---|
5004 | "inflate: * literal '%c'\n" : |
---|
5005 | "inflate: * literal 0x%02x\n", t->base)); |
---|
5006 | *q++ = (Byte)t->base; |
---|
5007 | m--; |
---|
5008 | continue; |
---|
5009 | } |
---|
5010 | do { |
---|
5011 | DUMPBITS(t->bits) |
---|
5012 | if (e & 16) |
---|
5013 | { |
---|
5014 | /* get extra bits for length */ |
---|
5015 | e &= 15; |
---|
5016 | c = t->base + ((uInt)b & inflate_mask[e]); |
---|
5017 | DUMPBITS(e) |
---|
5018 | Tracevv((stderr, "inflate: * length %u\n", c)); |
---|
5019 | |
---|
5020 | /* decode distance base of block to copy */ |
---|
5021 | GRABBITS(15); /* max bits for distance code */ |
---|
5022 | e = (t = td + ((uInt)b & md))->exop; |
---|
5023 | do { |
---|
5024 | DUMPBITS(t->bits) |
---|
5025 | if (e & 16) |
---|
5026 | { |
---|
5027 | /* get extra bits to add to distance base */ |
---|
5028 | e &= 15; |
---|
5029 | GRABBITS(e) /* get extra bits (up to 13) */ |
---|
5030 | d = t->base + ((uInt)b & inflate_mask[e]); |
---|
5031 | DUMPBITS(e) |
---|
5032 | Tracevv((stderr, "inflate: * distance %u\n", d)); |
---|
5033 | |
---|
5034 | /* do the copy */ |
---|
5035 | m -= c; |
---|
5036 | if ((uInt)(q - s->window) >= d) /* offset before dest */ |
---|
5037 | { /* just copy */ |
---|
5038 | r = q - d; |
---|
5039 | *q++ = *r++; c--; /* minimum count is three, */ |
---|
5040 | *q++ = *r++; c--; /* so unroll loop a little */ |
---|
5041 | } |
---|
5042 | else /* else offset after destination */ |
---|
5043 | { |
---|
5044 | e = d - (uInt)(q - s->window); /* bytes from offset to end */ |
---|
5045 | r = s->end - e; /* pointer to offset */ |
---|
5046 | if (c > e) /* if source crosses, */ |
---|
5047 | { |
---|
5048 | c -= e; /* copy to end of window */ |
---|
5049 | do { |
---|
5050 | *q++ = *r++; |
---|
5051 | } while (--e); |
---|
5052 | r = s->window; /* copy rest from start of window */ |
---|
5053 | } |
---|
5054 | } |
---|
5055 | do { /* copy all or what's left */ |
---|
5056 | *q++ = *r++; |
---|
5057 | } while (--c); |
---|
5058 | break; |
---|
5059 | } |
---|
5060 | else if ((e & 64) == 0) |
---|
5061 | e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; |
---|
5062 | else |
---|
5063 | { |
---|
5064 | z->msg = (char*)"invalid distance code"; |
---|
5065 | UNGRAB |
---|
5066 | UPDATE |
---|
5067 | return Z_DATA_ERROR; |
---|
5068 | } |
---|
5069 | } while (1); |
---|
5070 | break; |
---|
5071 | } |
---|
5072 | if ((e & 64) == 0) |
---|
5073 | { |
---|
5074 | if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) |
---|
5075 | { |
---|
5076 | DUMPBITS(t->bits) |
---|
5077 | Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? |
---|
5078 | "inflate: * literal '%c'\n" : |
---|
5079 | "inflate: * literal 0x%02x\n", t->base)); |
---|
5080 | *q++ = (Byte)t->base; |
---|
5081 | m--; |
---|
5082 | break; |
---|
5083 | } |
---|
5084 | } |
---|
5085 | else if (e & 32) |
---|
5086 | { |
---|
5087 | Tracevv((stderr, "inflate: * end of block\n")); |
---|
5088 | UNGRAB |
---|
5089 | UPDATE |
---|
5090 | return Z_STREAM_END; |
---|
5091 | } |
---|
5092 | else |
---|
5093 | { |
---|
5094 | z->msg = (char*)"invalid literal/length code"; |
---|
5095 | UNGRAB |
---|
5096 | UPDATE |
---|
5097 | return Z_DATA_ERROR; |
---|
5098 | } |
---|
5099 | } while (1); |
---|
5100 | } while (m >= 258 && n >= 10); |
---|
5101 | |
---|
5102 | /* not enough input or output--restore pointers and return */ |
---|
5103 | UNGRAB |
---|
5104 | UPDATE |
---|
5105 | return Z_OK; |
---|
5106 | } |
---|
5107 | /* --- inffast.c */ |
---|
5108 | |
---|
5109 | /* +++ zutil.c */ |
---|
5110 | /* zutil.c -- target dependent utility functions for the compression library |
---|
5111 | * Copyright (C) 1995-1996 Jean-loup Gailly. |
---|
5112 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
5113 | */ |
---|
5114 | |
---|
5115 | /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ |
---|
5116 | |
---|
5117 | #ifdef DEBUG_ZLIB |
---|
5118 | #include <stdio.h> |
---|
5119 | #endif |
---|
5120 | |
---|
5121 | /* #include "zutil.h" */ |
---|
5122 | |
---|
5123 | #ifndef NO_DUMMY_DECL |
---|
5124 | struct internal_state {int dummy;}; /* for buggy compilers */ |
---|
5125 | #endif |
---|
5126 | |
---|
5127 | #ifndef STDC |
---|
5128 | extern void exit OF((int)); |
---|
5129 | #endif |
---|
5130 | |
---|
5131 | const char *z_errmsg[10] = { |
---|
5132 | "need dictionary", /* Z_NEED_DICT 2 */ |
---|
5133 | "stream end", /* Z_STREAM_END 1 */ |
---|
5134 | "", /* Z_OK 0 */ |
---|
5135 | "file error", /* Z_ERRNO (-1) */ |
---|
5136 | "stream error", /* Z_STREAM_ERROR (-2) */ |
---|
5137 | "data error", /* Z_DATA_ERROR (-3) */ |
---|
5138 | "insufficient memory", /* Z_MEM_ERROR (-4) */ |
---|
5139 | "buffer error", /* Z_BUF_ERROR (-5) */ |
---|
5140 | "incompatible version",/* Z_VERSION_ERROR (-6) */ |
---|
5141 | ""}; |
---|
5142 | |
---|
5143 | |
---|
5144 | const char *zlibVersion() |
---|
5145 | { |
---|
5146 | return ZLIB_VERSION; |
---|
5147 | } |
---|
5148 | |
---|
5149 | #ifdef DEBUG_ZLIB |
---|
5150 | void z_error (m) |
---|
5151 | char *m; |
---|
5152 | { |
---|
5153 | fprintf(stderr, "%s\n", m); |
---|
5154 | exit(1); |
---|
5155 | } |
---|
5156 | #endif |
---|
5157 | |
---|
5158 | #ifndef HAVE_MEMCPY |
---|
5159 | |
---|
5160 | void zmemcpy(dest, source, len) |
---|
5161 | Bytef* dest; |
---|
5162 | Bytef* source; |
---|
5163 | uInt len; |
---|
5164 | { |
---|
5165 | if (len == 0) return; |
---|
5166 | do { |
---|
5167 | *dest++ = *source++; /* ??? to be unrolled */ |
---|
5168 | } while (--len != 0); |
---|
5169 | } |
---|
5170 | |
---|
5171 | int zmemcmp(s1, s2, len) |
---|
5172 | Bytef* s1; |
---|
5173 | Bytef* s2; |
---|
5174 | uInt len; |
---|
5175 | { |
---|
5176 | uInt j; |
---|
5177 | |
---|
5178 | for (j = 0; j < len; j++) { |
---|
5179 | if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; |
---|
5180 | } |
---|
5181 | return 0; |
---|
5182 | } |
---|
5183 | |
---|
5184 | void zmemzero(dest, len) |
---|
5185 | Bytef* dest; |
---|
5186 | uInt len; |
---|
5187 | { |
---|
5188 | if (len == 0) return; |
---|
5189 | do { |
---|
5190 | *dest++ = 0; /* ??? to be unrolled */ |
---|
5191 | } while (--len != 0); |
---|
5192 | } |
---|
5193 | #endif |
---|
5194 | |
---|
5195 | #ifdef __TURBOC__ |
---|
5196 | #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) |
---|
5197 | /* Small and medium model in Turbo C are for now limited to near allocation |
---|
5198 | * with reduced MAX_WBITS and MAX_MEM_LEVEL |
---|
5199 | */ |
---|
5200 | # define MY_ZCALLOC |
---|
5201 | |
---|
5202 | /* Turbo C malloc() does not allow dynamic allocation of 64K bytes |
---|
5203 | * and farmalloc(64K) returns a pointer with an offset of 8, so we |
---|
5204 | * must fix the pointer. Warning: the pointer must be put back to its |
---|
5205 | * original form in order to free it, use zcfree(). |
---|
5206 | */ |
---|
5207 | |
---|
5208 | #define MAX_PTR 10 |
---|
5209 | /* 10*64K = 640K */ |
---|
5210 | |
---|
5211 | local int next_ptr = 0; |
---|
5212 | |
---|
5213 | typedef struct ptr_table_s { |
---|
5214 | voidpf org_ptr; |
---|
5215 | voidpf new_ptr; |
---|
5216 | } ptr_table; |
---|
5217 | |
---|
5218 | local ptr_table table[MAX_PTR]; |
---|
5219 | /* This table is used to remember the original form of pointers |
---|
5220 | * to large buffers (64K). Such pointers are normalized with a zero offset. |
---|
5221 | * Since MSDOS is not a preemptive multitasking OS, this table is not |
---|
5222 | * protected from concurrent access. This hack doesn't work anyway on |
---|
5223 | * a protected system like OS/2. Use Microsoft C instead. |
---|
5224 | */ |
---|
5225 | |
---|
5226 | voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) |
---|
5227 | { |
---|
5228 | voidpf buf = opaque; /* just to make some compilers happy */ |
---|
5229 | ulg bsize = (ulg)items*size; |
---|
5230 | |
---|
5231 | /* If we allocate less than 65520 bytes, we assume that farmalloc |
---|
5232 | * will return a usable pointer which doesn't have to be normalized. |
---|
5233 | */ |
---|
5234 | if (bsize < 65520L) { |
---|
5235 | buf = farmalloc(bsize); |
---|
5236 | if (*(ush*)&buf != 0) return buf; |
---|
5237 | } else { |
---|
5238 | buf = farmalloc(bsize + 16L); |
---|
5239 | } |
---|
5240 | if (buf == NULL || next_ptr >= MAX_PTR) return NULL; |
---|
5241 | table[next_ptr].org_ptr = buf; |
---|
5242 | |
---|
5243 | /* Normalize the pointer to seg:0 */ |
---|
5244 | *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; |
---|
5245 | *(ush*)&buf = 0; |
---|
5246 | table[next_ptr++].new_ptr = buf; |
---|
5247 | return buf; |
---|
5248 | } |
---|
5249 | |
---|
5250 | void zcfree (voidpf opaque, voidpf ptr) |
---|
5251 | { |
---|
5252 | int n; |
---|
5253 | if (*(ush*)&ptr != 0) { /* object < 64K */ |
---|
5254 | farfree(ptr); |
---|
5255 | return; |
---|
5256 | } |
---|
5257 | /* Find the original pointer */ |
---|
5258 | for (n = 0; n < next_ptr; n++) { |
---|
5259 | if (ptr != table[n].new_ptr) continue; |
---|
5260 | |
---|
5261 | farfree(table[n].org_ptr); |
---|
5262 | while (++n < next_ptr) { |
---|
5263 | table[n-1] = table[n]; |
---|
5264 | } |
---|
5265 | next_ptr--; |
---|
5266 | return; |
---|
5267 | } |
---|
5268 | ptr = opaque; /* just to make some compilers happy */ |
---|
5269 | Assert(0, "zcfree: ptr not found"); |
---|
5270 | } |
---|
5271 | #endif |
---|
5272 | #endif /* __TURBOC__ */ |
---|
5273 | |
---|
5274 | |
---|
5275 | #if defined(M_I86) && !defined(__32BIT__) |
---|
5276 | /* Microsoft C in 16-bit mode */ |
---|
5277 | |
---|
5278 | # define MY_ZCALLOC |
---|
5279 | |
---|
5280 | #if (!defined(_MSC_VER) || (_MSC_VER < 600)) |
---|
5281 | # define _halloc halloc |
---|
5282 | # define _hfree hfree |
---|
5283 | #endif |
---|
5284 | |
---|
5285 | voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) |
---|
5286 | { |
---|
5287 | if (opaque) opaque = 0; /* to make compiler happy */ |
---|
5288 | return _halloc((long)items, size); |
---|
5289 | } |
---|
5290 | |
---|
5291 | void zcfree (voidpf opaque, voidpf ptr) |
---|
5292 | { |
---|
5293 | if (opaque) opaque = 0; /* to make compiler happy */ |
---|
5294 | _hfree(ptr); |
---|
5295 | } |
---|
5296 | |
---|
5297 | #endif /* MSC */ |
---|
5298 | |
---|
5299 | |
---|
5300 | #ifndef MY_ZCALLOC /* Any system without a special alloc function */ |
---|
5301 | |
---|
5302 | #ifndef STDC |
---|
5303 | extern voidp calloc OF((uInt items, uInt size)); |
---|
5304 | extern void free OF((voidpf ptr)); |
---|
5305 | #endif |
---|
5306 | |
---|
5307 | voidpf zcalloc (opaque, items, size) |
---|
5308 | voidpf opaque; |
---|
5309 | unsigned items; |
---|
5310 | unsigned size; |
---|
5311 | { |
---|
5312 | if (opaque) items += size - size; /* make compiler happy */ |
---|
5313 | return (voidpf)calloc(items, size); |
---|
5314 | } |
---|
5315 | |
---|
5316 | void zcfree (opaque, ptr) |
---|
5317 | voidpf opaque; |
---|
5318 | voidpf ptr; |
---|
5319 | { |
---|
5320 | free(ptr); |
---|
5321 | if (opaque) return; /* make compiler happy */ |
---|
5322 | } |
---|
5323 | |
---|
5324 | #endif /* MY_ZCALLOC */ |
---|
5325 | /* --- zutil.c */ |
---|
5326 | |
---|
5327 | /* +++ adler32.c */ |
---|
5328 | /* adler32.c -- compute the Adler-32 checksum of a data stream |
---|
5329 | * Copyright (C) 1995-1996 Mark Adler |
---|
5330 | * For conditions of distribution and use, see copyright notice in zlib.h |
---|
5331 | */ |
---|
5332 | |
---|
5333 | /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ |
---|
5334 | |
---|
5335 | /* #include "zlib.h" */ |
---|
5336 | |
---|
5337 | #define BASE 65521L /* largest prime smaller than 65536 */ |
---|
5338 | #define NMAX 5552 |
---|
5339 | /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ |
---|
5340 | |
---|
5341 | #define DO1(buf,i) {s1 += buf[i]; s2 += s1;} |
---|
5342 | #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1); |
---|
5343 | #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2); |
---|
5344 | #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); |
---|
5345 | #define DO16(buf) DO8(buf,0); DO8(buf,8); |
---|
5346 | |
---|
5347 | /* ========================================================================= */ |
---|
5348 | uLong adler32(adler, buf, len) |
---|
5349 | uLong adler; |
---|
5350 | const Bytef *buf; |
---|
5351 | uInt len; |
---|
5352 | { |
---|
5353 | unsigned long s1 = adler & 0xffff; |
---|
5354 | unsigned long s2 = (adler >> 16) & 0xffff; |
---|
5355 | int k; |
---|
5356 | |
---|
5357 | if (buf == Z_NULL) return 1L; |
---|
5358 | |
---|
5359 | while (len > 0) { |
---|
5360 | k = len < NMAX ? len : NMAX; |
---|
5361 | len -= k; |
---|
5362 | while (k >= 16) { |
---|
5363 | DO16(buf); |
---|
5364 | buf += 16; |
---|
5365 | k -= 16; |
---|
5366 | } |
---|
5367 | if (k != 0) do { |
---|
5368 | s1 += *buf++; |
---|
5369 | s2 += s1; |
---|
5370 | } while (--k); |
---|
5371 | s1 %= BASE; |
---|
5372 | s2 %= BASE; |
---|
5373 | } |
---|
5374 | return (s2 << 16) | s1; |
---|
5375 | } |
---|
5376 | /* --- adler32.c */ |
---|