111
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1 /* gzlib.c -- zlib functions common to reading and writing gzip files
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2 * Copyright (C) 2004-2017 Mark Adler
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3 * For conditions of distribution and use, see copyright notice in zlib.h
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4 */
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5
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6 #include "gzguts.h"
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7
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8 #if defined(_WIN32) && !defined(__BORLANDC__) && !defined(__MINGW32__)
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9 # define LSEEK _lseeki64
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10 #else
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11 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
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12 # define LSEEK lseek64
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13 #else
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14 # define LSEEK lseek
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15 #endif
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16 #endif
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17
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18 /* Local functions */
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19 local void gz_reset OF((gz_statep));
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20 local gzFile gz_open OF((const void *, int, const char *));
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21
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22 #if defined UNDER_CE
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23
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24 /* Map the Windows error number in ERROR to a locale-dependent error message
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25 string and return a pointer to it. Typically, the values for ERROR come
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26 from GetLastError.
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27
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28 The string pointed to shall not be modified by the application, but may be
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29 overwritten by a subsequent call to gz_strwinerror
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30
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31 The gz_strwinerror function does not change the current setting of
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32 GetLastError. */
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33 char ZLIB_INTERNAL *gz_strwinerror (error)
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34 DWORD error;
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35 {
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36 static char buf[1024];
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37
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38 wchar_t *msgbuf;
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39 DWORD lasterr = GetLastError();
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40 DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
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41 | FORMAT_MESSAGE_ALLOCATE_BUFFER,
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42 NULL,
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43 error,
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44 0, /* Default language */
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45 (LPVOID)&msgbuf,
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46 0,
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47 NULL);
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48 if (chars != 0) {
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49 /* If there is an \r\n appended, zap it. */
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50 if (chars >= 2
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51 && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
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52 chars -= 2;
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53 msgbuf[chars] = 0;
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54 }
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55
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56 if (chars > sizeof (buf) - 1) {
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57 chars = sizeof (buf) - 1;
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58 msgbuf[chars] = 0;
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59 }
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60
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61 wcstombs(buf, msgbuf, chars + 1);
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62 LocalFree(msgbuf);
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63 }
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64 else {
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65 sprintf(buf, "unknown win32 error (%ld)", error);
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66 }
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67
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68 SetLastError(lasterr);
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69 return buf;
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70 }
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71
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72 #endif /* UNDER_CE */
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73
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74 /* Reset gzip file state */
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75 local void gz_reset(state)
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76 gz_statep state;
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77 {
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78 state->x.have = 0; /* no output data available */
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79 if (state->mode == GZ_READ) { /* for reading ... */
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80 state->eof = 0; /* not at end of file */
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81 state->past = 0; /* have not read past end yet */
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82 state->how = LOOK; /* look for gzip header */
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83 }
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84 state->seek = 0; /* no seek request pending */
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85 gz_error(state, Z_OK, NULL); /* clear error */
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86 state->x.pos = 0; /* no uncompressed data yet */
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87 state->strm.avail_in = 0; /* no input data yet */
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88 }
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89
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90 /* Open a gzip file either by name or file descriptor. */
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91 local gzFile gz_open(path, fd, mode)
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92 const void *path;
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93 int fd;
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94 const char *mode;
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95 {
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96 gz_statep state;
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97 z_size_t len;
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98 int oflag;
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99 #ifdef O_CLOEXEC
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100 int cloexec = 0;
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101 #endif
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102 #ifdef O_EXCL
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103 int exclusive = 0;
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104 #endif
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105
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106 /* check input */
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107 if (path == NULL)
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108 return NULL;
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109
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110 /* allocate gzFile structure to return */
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111 state = (gz_statep)malloc(sizeof(gz_state));
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112 if (state == NULL)
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113 return NULL;
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114 state->size = 0; /* no buffers allocated yet */
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115 state->want = GZBUFSIZE; /* requested buffer size */
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116 state->msg = NULL; /* no error message yet */
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117
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118 /* interpret mode */
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119 state->mode = GZ_NONE;
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120 state->level = Z_DEFAULT_COMPRESSION;
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121 state->strategy = Z_DEFAULT_STRATEGY;
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122 state->direct = 0;
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123 while (*mode) {
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124 if (*mode >= '0' && *mode <= '9')
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125 state->level = *mode - '0';
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126 else
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127 switch (*mode) {
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128 case 'r':
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129 state->mode = GZ_READ;
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130 break;
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131 #ifndef NO_GZCOMPRESS
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132 case 'w':
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133 state->mode = GZ_WRITE;
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134 break;
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135 case 'a':
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136 state->mode = GZ_APPEND;
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137 break;
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138 #endif
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139 case '+': /* can't read and write at the same time */
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140 free(state);
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141 return NULL;
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142 case 'b': /* ignore -- will request binary anyway */
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143 break;
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144 #ifdef O_CLOEXEC
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145 case 'e':
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146 cloexec = 1;
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147 break;
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148 #endif
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149 #ifdef O_EXCL
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150 case 'x':
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151 exclusive = 1;
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152 break;
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153 #endif
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154 case 'f':
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155 state->strategy = Z_FILTERED;
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156 break;
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157 case 'h':
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158 state->strategy = Z_HUFFMAN_ONLY;
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159 break;
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160 case 'R':
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161 state->strategy = Z_RLE;
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162 break;
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163 case 'F':
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164 state->strategy = Z_FIXED;
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165 break;
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166 case 'T':
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167 state->direct = 1;
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168 break;
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169 default: /* could consider as an error, but just ignore */
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170 ;
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171 }
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172 mode++;
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173 }
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174
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175 /* must provide an "r", "w", or "a" */
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176 if (state->mode == GZ_NONE) {
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177 free(state);
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178 return NULL;
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179 }
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180
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181 /* can't force transparent read */
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182 if (state->mode == GZ_READ) {
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183 if (state->direct) {
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184 free(state);
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185 return NULL;
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186 }
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187 state->direct = 1; /* for empty file */
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188 }
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189
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190 /* save the path name for error messages */
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191 #ifdef WIDECHAR
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192 if (fd == -2) {
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193 len = wcstombs(NULL, path, 0);
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194 if (len == (z_size_t)-1)
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195 len = 0;
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196 }
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197 else
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198 #endif
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199 len = strlen((const char *)path);
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200 state->path = (char *)malloc(len + 1);
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201 if (state->path == NULL) {
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202 free(state);
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203 return NULL;
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204 }
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205 #ifdef WIDECHAR
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206 if (fd == -2)
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207 if (len)
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208 wcstombs(state->path, path, len + 1);
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209 else
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210 *(state->path) = 0;
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211 else
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212 #endif
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213 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
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214 (void)snprintf(state->path, len + 1, "%s", (const char *)path);
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215 #else
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216 strcpy(state->path, path);
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217 #endif
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218
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219 /* compute the flags for open() */
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220 oflag =
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221 #ifdef O_LARGEFILE
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222 O_LARGEFILE |
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223 #endif
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224 #ifdef O_BINARY
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225 O_BINARY |
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226 #endif
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227 #ifdef O_CLOEXEC
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228 (cloexec ? O_CLOEXEC : 0) |
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229 #endif
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230 (state->mode == GZ_READ ?
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231 O_RDONLY :
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232 (O_WRONLY | O_CREAT |
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233 #ifdef O_EXCL
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234 (exclusive ? O_EXCL : 0) |
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235 #endif
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236 (state->mode == GZ_WRITE ?
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237 O_TRUNC :
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238 O_APPEND)));
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239
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240 /* open the file with the appropriate flags (or just use fd) */
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241 state->fd = fd > -1 ? fd : (
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242 #ifdef WIDECHAR
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243 fd == -2 ? _wopen(path, oflag, 0666) :
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244 #endif
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245 open((const char *)path, oflag, 0666));
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246 if (state->fd == -1) {
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247 free(state->path);
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248 free(state);
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249 return NULL;
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250 }
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251 if (state->mode == GZ_APPEND) {
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252 LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */
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253 state->mode = GZ_WRITE; /* simplify later checks */
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254 }
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255
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256 /* save the current position for rewinding (only if reading) */
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257 if (state->mode == GZ_READ) {
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258 state->start = LSEEK(state->fd, 0, SEEK_CUR);
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259 if (state->start == -1) state->start = 0;
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260 }
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261
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262 /* initialize stream */
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263 gz_reset(state);
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264
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265 /* return stream */
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266 return (gzFile)state;
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267 }
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268
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269 /* -- see zlib.h -- */
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270 gzFile ZEXPORT gzopen(path, mode)
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271 const char *path;
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272 const char *mode;
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273 {
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274 return gz_open(path, -1, mode);
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275 }
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276
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277 /* -- see zlib.h -- */
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278 gzFile ZEXPORT gzopen64(path, mode)
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279 const char *path;
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280 const char *mode;
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281 {
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282 return gz_open(path, -1, mode);
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283 }
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284
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285 /* -- see zlib.h -- */
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286 gzFile ZEXPORT gzdopen(fd, mode)
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287 int fd;
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288 const char *mode;
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289 {
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290 char *path; /* identifier for error messages */
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291 gzFile gz;
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292
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293 if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
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294 return NULL;
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295 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
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296 (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
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297 #else
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298 sprintf(path, "<fd:%d>", fd); /* for debugging */
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299 #endif
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300 gz = gz_open(path, fd, mode);
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301 free(path);
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302 return gz;
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303 }
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304
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305 /* -- see zlib.h -- */
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306 #ifdef WIDECHAR
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307 gzFile ZEXPORT gzopen_w(path, mode)
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308 const wchar_t *path;
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309 const char *mode;
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310 {
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311 return gz_open(path, -2, mode);
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312 }
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313 #endif
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314
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315 /* -- see zlib.h -- */
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316 int ZEXPORT gzbuffer(file, size)
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317 gzFile file;
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318 unsigned size;
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319 {
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320 gz_statep state;
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321
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322 /* get internal structure and check integrity */
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323 if (file == NULL)
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324 return -1;
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325 state = (gz_statep)file;
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326 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
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327 return -1;
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328
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329 /* make sure we haven't already allocated memory */
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330 if (state->size != 0)
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331 return -1;
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332
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333 /* check and set requested size */
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334 if ((size << 1) < size)
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335 return -1; /* need to be able to double it */
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336 if (size < 2)
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337 size = 2; /* need two bytes to check magic header */
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338 state->want = size;
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339 return 0;
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340 }
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341
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342 /* -- see zlib.h -- */
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343 int ZEXPORT gzrewind(file)
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344 gzFile file;
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345 {
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346 gz_statep state;
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347
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348 /* get internal structure */
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349 if (file == NULL)
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350 return -1;
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351 state = (gz_statep)file;
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352
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353 /* check that we're reading and that there's no error */
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354 if (state->mode != GZ_READ ||
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355 (state->err != Z_OK && state->err != Z_BUF_ERROR))
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356 return -1;
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357
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358 /* back up and start over */
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359 if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
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360 return -1;
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361 gz_reset(state);
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362 return 0;
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363 }
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364
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365 /* -- see zlib.h -- */
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366 z_off64_t ZEXPORT gzseek64(file, offset, whence)
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367 gzFile file;
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368 z_off64_t offset;
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369 int whence;
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370 {
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371 unsigned n;
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372 z_off64_t ret;
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373 gz_statep state;
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374
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375 /* get internal structure and check integrity */
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376 if (file == NULL)
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377 return -1;
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378 state = (gz_statep)file;
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379 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
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380 return -1;
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381
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382 /* check that there's no error */
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383 if (state->err != Z_OK && state->err != Z_BUF_ERROR)
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384 return -1;
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385
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386 /* can only seek from start or relative to current position */
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387 if (whence != SEEK_SET && whence != SEEK_CUR)
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388 return -1;
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389
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390 /* normalize offset to a SEEK_CUR specification */
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391 if (whence == SEEK_SET)
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392 offset -= state->x.pos;
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393 else if (state->seek)
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394 offset += state->skip;
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395 state->seek = 0;
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396
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397 /* if within raw area while reading, just go there */
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398 if (state->mode == GZ_READ && state->how == COPY &&
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399 state->x.pos + offset >= 0) {
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400 ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
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401 if (ret == -1)
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402 return -1;
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403 state->x.have = 0;
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404 state->eof = 0;
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405 state->past = 0;
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406 state->seek = 0;
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407 gz_error(state, Z_OK, NULL);
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408 state->strm.avail_in = 0;
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409 state->x.pos += offset;
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410 return state->x.pos;
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411 }
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412
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413 /* calculate skip amount, rewinding if needed for back seek when reading */
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414 if (offset < 0) {
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415 if (state->mode != GZ_READ) /* writing -- can't go backwards */
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416 return -1;
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417 offset += state->x.pos;
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418 if (offset < 0) /* before start of file! */
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419 return -1;
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420 if (gzrewind(file) == -1) /* rewind, then skip to offset */
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421 return -1;
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422 }
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423
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424 /* if reading, skip what's in output buffer (one less gzgetc() check) */
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425 if (state->mode == GZ_READ) {
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426 n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
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427 (unsigned)offset : state->x.have;
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428 state->x.have -= n;
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429 state->x.next += n;
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430 state->x.pos += n;
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431 offset -= n;
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432 }
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433
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434 /* request skip (if not zero) */
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435 if (offset) {
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436 state->seek = 1;
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437 state->skip = offset;
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438 }
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439 return state->x.pos + offset;
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440 }
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441
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442 /* -- see zlib.h -- */
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443 z_off_t ZEXPORT gzseek(file, offset, whence)
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444 gzFile file;
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445 z_off_t offset;
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446 int whence;
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447 {
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448 z_off64_t ret;
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449
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450 ret = gzseek64(file, (z_off64_t)offset, whence);
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451 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
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452 }
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453
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454 /* -- see zlib.h -- */
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455 z_off64_t ZEXPORT gztell64(file)
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456 gzFile file;
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457 {
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458 gz_statep state;
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459
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460 /* get internal structure and check integrity */
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461 if (file == NULL)
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462 return -1;
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463 state = (gz_statep)file;
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464 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
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465 return -1;
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466
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467 /* return position */
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468 return state->x.pos + (state->seek ? state->skip : 0);
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469 }
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470
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471 /* -- see zlib.h -- */
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472 z_off_t ZEXPORT gztell(file)
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473 gzFile file;
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474 {
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475 z_off64_t ret;
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476
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477 ret = gztell64(file);
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478 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
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479 }
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480
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481 /* -- see zlib.h -- */
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482 z_off64_t ZEXPORT gzoffset64(file)
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483 gzFile file;
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484 {
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485 z_off64_t offset;
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486 gz_statep state;
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487
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488 /* get internal structure and check integrity */
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489 if (file == NULL)
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490 return -1;
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491 state = (gz_statep)file;
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492 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
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493 return -1;
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494
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495 /* compute and return effective offset in file */
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496 offset = LSEEK(state->fd, 0, SEEK_CUR);
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497 if (offset == -1)
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498 return -1;
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499 if (state->mode == GZ_READ) /* reading */
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500 offset -= state->strm.avail_in; /* don't count buffered input */
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501 return offset;
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502 }
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503
|
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504 /* -- see zlib.h -- */
|
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505 z_off_t ZEXPORT gzoffset(file)
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506 gzFile file;
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507 {
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508 z_off64_t ret;
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509
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510 ret = gzoffset64(file);
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511 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
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512 }
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513
|
|
514 /* -- see zlib.h -- */
|
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515 int ZEXPORT gzeof(file)
|
|
516 gzFile file;
|
|
517 {
|
|
518 gz_statep state;
|
|
519
|
|
520 /* get internal structure and check integrity */
|
|
521 if (file == NULL)
|
|
522 return 0;
|
|
523 state = (gz_statep)file;
|
|
524 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
|
|
525 return 0;
|
|
526
|
|
527 /* return end-of-file state */
|
|
528 return state->mode == GZ_READ ? state->past : 0;
|
|
529 }
|
|
530
|
|
531 /* -- see zlib.h -- */
|
|
532 const char * ZEXPORT gzerror(file, errnum)
|
|
533 gzFile file;
|
|
534 int *errnum;
|
|
535 {
|
|
536 gz_statep state;
|
|
537
|
|
538 /* get internal structure and check integrity */
|
|
539 if (file == NULL)
|
|
540 return NULL;
|
|
541 state = (gz_statep)file;
|
|
542 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
|
|
543 return NULL;
|
|
544
|
|
545 /* return error information */
|
|
546 if (errnum != NULL)
|
|
547 *errnum = state->err;
|
|
548 return state->err == Z_MEM_ERROR ? "out of memory" :
|
|
549 (state->msg == NULL ? "" : state->msg);
|
|
550 }
|
|
551
|
|
552 /* -- see zlib.h -- */
|
|
553 void ZEXPORT gzclearerr(file)
|
|
554 gzFile file;
|
|
555 {
|
|
556 gz_statep state;
|
|
557
|
|
558 /* get internal structure and check integrity */
|
|
559 if (file == NULL)
|
|
560 return;
|
|
561 state = (gz_statep)file;
|
|
562 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
|
|
563 return;
|
|
564
|
|
565 /* clear error and end-of-file */
|
|
566 if (state->mode == GZ_READ) {
|
|
567 state->eof = 0;
|
|
568 state->past = 0;
|
|
569 }
|
|
570 gz_error(state, Z_OK, NULL);
|
|
571 }
|
|
572
|
|
573 /* Create an error message in allocated memory and set state->err and
|
|
574 state->msg accordingly. Free any previous error message already there. Do
|
|
575 not try to free or allocate space if the error is Z_MEM_ERROR (out of
|
|
576 memory). Simply save the error message as a static string. If there is an
|
|
577 allocation failure constructing the error message, then convert the error to
|
|
578 out of memory. */
|
|
579 void ZLIB_INTERNAL gz_error(state, err, msg)
|
|
580 gz_statep state;
|
|
581 int err;
|
|
582 const char *msg;
|
|
583 {
|
|
584 /* free previously allocated message and clear */
|
|
585 if (state->msg != NULL) {
|
|
586 if (state->err != Z_MEM_ERROR)
|
|
587 free(state->msg);
|
|
588 state->msg = NULL;
|
|
589 }
|
|
590
|
|
591 /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
|
|
592 if (err != Z_OK && err != Z_BUF_ERROR)
|
|
593 state->x.have = 0;
|
|
594
|
|
595 /* set error code, and if no message, then done */
|
|
596 state->err = err;
|
|
597 if (msg == NULL)
|
|
598 return;
|
|
599
|
|
600 /* for an out of memory error, return literal string when requested */
|
|
601 if (err == Z_MEM_ERROR)
|
|
602 return;
|
|
603
|
|
604 /* construct error message with path */
|
|
605 if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
|
|
606 NULL) {
|
|
607 state->err = Z_MEM_ERROR;
|
|
608 return;
|
|
609 }
|
|
610 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
|
|
611 (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
|
|
612 "%s%s%s", state->path, ": ", msg);
|
|
613 #else
|
|
614 strcpy(state->msg, state->path);
|
|
615 strcat(state->msg, ": ");
|
|
616 strcat(state->msg, msg);
|
|
617 #endif
|
|
618 }
|
|
619
|
|
620 #ifndef INT_MAX
|
|
621 /* portably return maximum value for an int (when limits.h presumed not
|
|
622 available) -- we need to do this to cover cases where 2's complement not
|
|
623 used, since C standard permits 1's complement and sign-bit representations,
|
|
624 otherwise we could just use ((unsigned)-1) >> 1 */
|
|
625 unsigned ZLIB_INTERNAL gz_intmax()
|
|
626 {
|
|
627 unsigned p, q;
|
|
628
|
|
629 p = 1;
|
|
630 do {
|
|
631 q = p;
|
|
632 p <<= 1;
|
|
633 p++;
|
|
634 } while (p > q);
|
|
635 return q >> 1;
|
|
636 }
|
|
637 #endif
|