[9] | 1 | /* gzlib.c -- zlib functions common to reading and writing gzip files |
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| 2 | * Copyright (C) 2004, 2010 Mark Adler |
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| 3 | * For conditions of distribution and use, see copyright notice in zlib.h |
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| 4 | */ |
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| 5 | |
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| 6 | #include "gzguts.h" |
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| 7 | |
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| 8 | #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 |
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| 9 | # define LSEEK lseek64 |
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| 10 | #else |
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| 11 | # define LSEEK lseek |
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| 12 | #endif |
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| 13 | |
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| 14 | /* Local functions */ |
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| 15 | local void gz_reset OF((gz_statep)); |
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| 16 | local gzFile gz_open OF((const char *, int, const char *)); |
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| 17 | |
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| 18 | #if defined UNDER_CE |
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| 19 | |
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| 20 | /* Map the Windows error number in ERROR to a locale-dependent error message |
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| 21 | string and return a pointer to it. Typically, the values for ERROR come |
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| 22 | from GetLastError. |
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| 23 | |
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| 24 | The string pointed to shall not be modified by the application, but may be |
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| 25 | overwritten by a subsequent call to gz_strwinerror |
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| 26 | |
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| 27 | The gz_strwinerror function does not change the current setting of |
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| 28 | GetLastError. */ |
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| 29 | char ZLIB_INTERNAL *gz_strwinerror (error) |
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| 30 | DWORD error; |
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| 31 | { |
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| 32 | static char buf[1024]; |
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| 33 | |
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| 34 | wchar_t *msgbuf; |
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| 35 | DWORD lasterr = GetLastError(); |
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| 36 | DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
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| 37 | | FORMAT_MESSAGE_ALLOCATE_BUFFER, |
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| 38 | NULL, |
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| 39 | error, |
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| 40 | 0, /* Default language */ |
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| 41 | (LPVOID)&msgbuf, |
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| 42 | 0, |
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| 43 | NULL); |
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| 44 | if (chars != 0) { |
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| 45 | /* If there is an \r\n appended, zap it. */ |
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| 46 | if (chars >= 2 |
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| 47 | && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') { |
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| 48 | chars -= 2; |
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| 49 | msgbuf[chars] = 0; |
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| 50 | } |
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| 51 | |
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| 52 | if (chars > sizeof (buf) - 1) { |
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| 53 | chars = sizeof (buf) - 1; |
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| 54 | msgbuf[chars] = 0; |
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| 55 | } |
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| 56 | |
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| 57 | wcstombs(buf, msgbuf, chars + 1); |
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| 58 | LocalFree(msgbuf); |
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| 59 | } |
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| 60 | else { |
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| 61 | sprintf(buf, "unknown win32 error (%ld)", error); |
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| 62 | } |
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| 63 | |
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| 64 | SetLastError(lasterr); |
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| 65 | return buf; |
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| 66 | } |
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| 67 | |
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| 68 | #endif /* UNDER_CE */ |
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| 69 | |
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| 70 | /* Reset gzip file state */ |
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| 71 | local void gz_reset(state) |
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| 72 | gz_statep state; |
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| 73 | { |
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| 74 | if (state->mode == GZ_READ) { /* for reading ... */ |
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| 75 | state->have = 0; /* no output data available */ |
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| 76 | state->eof = 0; /* not at end of file */ |
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| 77 | state->how = LOOK; /* look for gzip header */ |
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| 78 | state->direct = 1; /* default for empty file */ |
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| 79 | } |
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| 80 | state->seek = 0; /* no seek request pending */ |
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| 81 | gz_error(state, Z_OK, NULL); /* clear error */ |
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| 82 | state->pos = 0; /* no uncompressed data yet */ |
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| 83 | state->strm.avail_in = 0; /* no input data yet */ |
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| 84 | } |
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| 85 | |
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| 86 | /* Open a gzip file either by name or file descriptor. */ |
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| 87 | local gzFile gz_open(path, fd, mode) |
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| 88 | const char *path; |
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| 89 | int fd; |
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| 90 | const char *mode; |
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| 91 | { |
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| 92 | gz_statep state; |
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| 93 | |
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| 94 | /* allocate gzFile structure to return */ |
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| 95 | state = malloc(sizeof(gz_state)); |
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| 96 | if (state == NULL) |
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| 97 | return NULL; |
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| 98 | state->size = 0; /* no buffers allocated yet */ |
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| 99 | state->want = GZBUFSIZE; /* requested buffer size */ |
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| 100 | state->msg = NULL; /* no error message yet */ |
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| 101 | |
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| 102 | /* interpret mode */ |
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| 103 | state->mode = GZ_NONE; |
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| 104 | state->level = Z_DEFAULT_COMPRESSION; |
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| 105 | state->strategy = Z_DEFAULT_STRATEGY; |
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| 106 | while (*mode) { |
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| 107 | if (*mode >= '0' && *mode <= '9') |
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| 108 | state->level = *mode - '0'; |
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| 109 | else |
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| 110 | switch (*mode) { |
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| 111 | case 'r': |
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| 112 | state->mode = GZ_READ; |
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| 113 | break; |
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| 114 | #ifndef NO_GZCOMPRESS |
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| 115 | case 'w': |
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| 116 | state->mode = GZ_WRITE; |
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| 117 | break; |
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| 118 | case 'a': |
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| 119 | state->mode = GZ_APPEND; |
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| 120 | break; |
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| 121 | #endif |
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| 122 | case '+': /* can't read and write at the same time */ |
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| 123 | free(state); |
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| 124 | return NULL; |
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| 125 | case 'b': /* ignore -- will request binary anyway */ |
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| 126 | break; |
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| 127 | case 'f': |
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| 128 | state->strategy = Z_FILTERED; |
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| 129 | break; |
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| 130 | case 'h': |
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| 131 | state->strategy = Z_HUFFMAN_ONLY; |
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| 132 | break; |
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| 133 | case 'R': |
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| 134 | state->strategy = Z_RLE; |
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| 135 | break; |
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| 136 | case 'F': |
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| 137 | state->strategy = Z_FIXED; |
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| 138 | default: /* could consider as an error, but just ignore */ |
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| 139 | ; |
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| 140 | } |
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| 141 | mode++; |
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| 142 | } |
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| 143 | |
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| 144 | /* must provide an "r", "w", or "a" */ |
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| 145 | if (state->mode == GZ_NONE) { |
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| 146 | free(state); |
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| 147 | return NULL; |
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| 148 | } |
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| 149 | |
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| 150 | /* save the path name for error messages */ |
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| 151 | state->path = malloc(strlen(path) + 1); |
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| 152 | if (state->path == NULL) { |
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| 153 | free(state); |
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| 154 | return NULL; |
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| 155 | } |
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| 156 | strcpy(state->path, path); |
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| 157 | |
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| 158 | /* open the file with the appropriate mode (or just use fd) */ |
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| 159 | state->fd = fd != -1 ? fd : |
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| 160 | open(path, |
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| 161 | #ifdef O_LARGEFILE |
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| 162 | O_LARGEFILE | |
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| 163 | #endif |
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| 164 | #ifdef O_BINARY |
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| 165 | O_BINARY | |
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| 166 | #endif |
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| 167 | (state->mode == GZ_READ ? |
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| 168 | O_RDONLY : |
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| 169 | (O_WRONLY | O_CREAT | ( |
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| 170 | state->mode == GZ_WRITE ? |
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| 171 | O_TRUNC : |
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| 172 | O_APPEND))), |
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| 173 | 0666); |
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| 174 | if (state->fd == -1) { |
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| 175 | free(state->path); |
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| 176 | free(state); |
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| 177 | return NULL; |
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| 178 | } |
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| 179 | if (state->mode == GZ_APPEND) |
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| 180 | state->mode = GZ_WRITE; /* simplify later checks */ |
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| 181 | |
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| 182 | /* save the current position for rewinding (only if reading) */ |
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| 183 | if (state->mode == GZ_READ) { |
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| 184 | state->start = LSEEK(state->fd, 0, SEEK_CUR); |
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| 185 | if (state->start == -1) state->start = 0; |
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| 186 | } |
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| 187 | |
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| 188 | /* initialize stream */ |
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| 189 | gz_reset(state); |
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| 190 | |
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| 191 | /* return stream */ |
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| 192 | return (gzFile)state; |
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| 193 | } |
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| 194 | |
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| 195 | /* -- see zlib.h -- */ |
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| 196 | gzFile ZEXPORT gzopen(path, mode) |
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| 197 | const char *path; |
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| 198 | const char *mode; |
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| 199 | { |
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| 200 | return gz_open(path, -1, mode); |
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| 201 | } |
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| 202 | |
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| 203 | /* -- see zlib.h -- */ |
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| 204 | gzFile ZEXPORT gzopen64(path, mode) |
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| 205 | const char *path; |
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| 206 | const char *mode; |
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| 207 | { |
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| 208 | return gz_open(path, -1, mode); |
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| 209 | } |
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| 210 | |
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| 211 | /* -- see zlib.h -- */ |
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| 212 | gzFile ZEXPORT gzdopen(fd, mode) |
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| 213 | int fd; |
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| 214 | const char *mode; |
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| 215 | { |
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| 216 | char *path; /* identifier for error messages */ |
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| 217 | gzFile gz; |
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| 218 | |
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| 219 | if (fd == -1 || (path = malloc(7 + 3 * sizeof(int))) == NULL) |
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| 220 | return NULL; |
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| 221 | sprintf(path, "<fd:%d>", fd); /* for debugging */ |
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| 222 | gz = gz_open(path, fd, mode); |
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| 223 | free(path); |
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| 224 | return gz; |
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| 225 | } |
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| 226 | |
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| 227 | /* -- see zlib.h -- */ |
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| 228 | int ZEXPORT gzbuffer(file, size) |
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| 229 | gzFile file; |
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| 230 | unsigned size; |
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| 231 | { |
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| 232 | gz_statep state; |
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| 233 | |
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| 234 | /* get internal structure and check integrity */ |
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| 235 | if (file == NULL) |
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| 236 | return -1; |
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| 237 | state = (gz_statep)file; |
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| 238 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 239 | return -1; |
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| 240 | |
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| 241 | /* make sure we haven't already allocated memory */ |
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| 242 | if (state->size != 0) |
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| 243 | return -1; |
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| 244 | |
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| 245 | /* check and set requested size */ |
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| 246 | if (size == 0) |
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| 247 | return -1; |
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| 248 | state->want = size; |
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| 249 | return 0; |
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| 250 | } |
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| 251 | |
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| 252 | /* -- see zlib.h -- */ |
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| 253 | int ZEXPORT gzrewind(file) |
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| 254 | gzFile file; |
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| 255 | { |
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| 256 | gz_statep state; |
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| 257 | |
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| 258 | /* get internal structure */ |
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| 259 | if (file == NULL) |
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| 260 | return -1; |
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| 261 | state = (gz_statep)file; |
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| 262 | |
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| 263 | /* check that we're reading and that there's no error */ |
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| 264 | if (state->mode != GZ_READ || state->err != Z_OK) |
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| 265 | return -1; |
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| 266 | |
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| 267 | /* back up and start over */ |
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| 268 | if (LSEEK(state->fd, state->start, SEEK_SET) == -1) |
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| 269 | return -1; |
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| 270 | gz_reset(state); |
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| 271 | return 0; |
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| 272 | } |
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| 273 | |
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| 274 | /* -- see zlib.h -- */ |
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| 275 | z_off64_t ZEXPORT gzseek64(file, offset, whence) |
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| 276 | gzFile file; |
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| 277 | z_off64_t offset; |
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| 278 | int whence; |
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| 279 | { |
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| 280 | unsigned n; |
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| 281 | z_off64_t ret; |
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| 282 | gz_statep state; |
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| 283 | |
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| 284 | /* get internal structure and check integrity */ |
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| 285 | if (file == NULL) |
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| 286 | return -1; |
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| 287 | state = (gz_statep)file; |
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| 288 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 289 | return -1; |
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| 290 | |
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| 291 | /* check that there's no error */ |
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| 292 | if (state->err != Z_OK) |
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| 293 | return -1; |
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| 294 | |
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| 295 | /* can only seek from start or relative to current position */ |
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| 296 | if (whence != SEEK_SET && whence != SEEK_CUR) |
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| 297 | return -1; |
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| 298 | |
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| 299 | /* normalize offset to a SEEK_CUR specification */ |
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| 300 | if (whence == SEEK_SET) |
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| 301 | offset -= state->pos; |
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| 302 | else if (state->seek) |
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| 303 | offset += state->skip; |
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| 304 | state->seek = 0; |
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| 305 | |
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| 306 | /* if within raw area while reading, just go there */ |
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| 307 | if (state->mode == GZ_READ && state->how == COPY && |
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| 308 | state->pos + offset >= state->raw) { |
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| 309 | ret = LSEEK(state->fd, offset - state->have, SEEK_CUR); |
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| 310 | if (ret == -1) |
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| 311 | return -1; |
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| 312 | state->have = 0; |
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| 313 | state->eof = 0; |
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| 314 | state->seek = 0; |
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| 315 | gz_error(state, Z_OK, NULL); |
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| 316 | state->strm.avail_in = 0; |
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| 317 | state->pos += offset; |
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| 318 | return state->pos; |
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| 319 | } |
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| 320 | |
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| 321 | /* calculate skip amount, rewinding if needed for back seek when reading */ |
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| 322 | if (offset < 0) { |
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| 323 | if (state->mode != GZ_READ) /* writing -- can't go backwards */ |
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| 324 | return -1; |
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| 325 | offset += state->pos; |
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| 326 | if (offset < 0) /* before start of file! */ |
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| 327 | return -1; |
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| 328 | if (gzrewind(file) == -1) /* rewind, then skip to offset */ |
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| 329 | return -1; |
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| 330 | } |
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| 331 | |
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| 332 | /* if reading, skip what's in output buffer (one less gzgetc() check) */ |
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| 333 | if (state->mode == GZ_READ) { |
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| 334 | n = GT_OFF(state->have) || (z_off64_t)state->have > offset ? |
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| 335 | (unsigned)offset : state->have; |
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| 336 | state->have -= n; |
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| 337 | state->next += n; |
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| 338 | state->pos += n; |
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| 339 | offset -= n; |
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| 340 | } |
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| 341 | |
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| 342 | /* request skip (if not zero) */ |
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| 343 | if (offset) { |
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| 344 | state->seek = 1; |
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| 345 | state->skip = offset; |
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| 346 | } |
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| 347 | return state->pos + offset; |
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| 348 | } |
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| 349 | |
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| 350 | /* -- see zlib.h -- */ |
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| 351 | z_off_t ZEXPORT gzseek(file, offset, whence) |
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| 352 | gzFile file; |
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| 353 | z_off_t offset; |
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| 354 | int whence; |
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| 355 | { |
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| 356 | z_off64_t ret; |
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| 357 | |
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| 358 | ret = gzseek64(file, (z_off64_t)offset, whence); |
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| 359 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
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| 360 | } |
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| 361 | |
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| 362 | /* -- see zlib.h -- */ |
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| 363 | z_off64_t ZEXPORT gztell64(file) |
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| 364 | gzFile file; |
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| 365 | { |
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| 366 | gz_statep state; |
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| 367 | |
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| 368 | /* get internal structure and check integrity */ |
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| 369 | if (file == NULL) |
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| 370 | return -1; |
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| 371 | state = (gz_statep)file; |
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| 372 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 373 | return -1; |
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| 374 | |
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| 375 | /* return position */ |
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| 376 | return state->pos + (state->seek ? state->skip : 0); |
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| 377 | } |
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| 378 | |
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| 379 | /* -- see zlib.h -- */ |
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| 380 | z_off_t ZEXPORT gztell(file) |
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| 381 | gzFile file; |
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| 382 | { |
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| 383 | z_off64_t ret; |
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| 384 | |
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| 385 | ret = gztell64(file); |
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| 386 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
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| 387 | } |
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| 388 | |
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| 389 | /* -- see zlib.h -- */ |
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| 390 | z_off64_t ZEXPORT gzoffset64(file) |
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| 391 | gzFile file; |
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| 392 | { |
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| 393 | z_off64_t offset; |
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| 394 | gz_statep state; |
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| 395 | |
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| 396 | /* get internal structure and check integrity */ |
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| 397 | if (file == NULL) |
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| 398 | return -1; |
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| 399 | state = (gz_statep)file; |
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| 400 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 401 | return -1; |
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| 402 | |
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| 403 | /* compute and return effective offset in file */ |
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| 404 | offset = LSEEK(state->fd, 0, SEEK_CUR); |
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| 405 | if (offset == -1) |
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| 406 | return -1; |
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| 407 | if (state->mode == GZ_READ) /* reading */ |
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| 408 | offset -= state->strm.avail_in; /* don't count buffered input */ |
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| 409 | return offset; |
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| 410 | } |
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| 411 | |
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| 412 | /* -- see zlib.h -- */ |
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| 413 | z_off_t ZEXPORT gzoffset(file) |
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| 414 | gzFile file; |
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| 415 | { |
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| 416 | z_off64_t ret; |
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| 417 | |
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| 418 | ret = gzoffset64(file); |
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| 419 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
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| 420 | } |
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| 421 | |
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| 422 | /* -- see zlib.h -- */ |
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| 423 | int ZEXPORT gzeof(file) |
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| 424 | gzFile file; |
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| 425 | { |
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| 426 | gz_statep state; |
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| 427 | |
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| 428 | /* get internal structure and check integrity */ |
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| 429 | if (file == NULL) |
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| 430 | return 0; |
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| 431 | state = (gz_statep)file; |
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| 432 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 433 | return 0; |
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| 434 | |
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| 435 | /* return end-of-file state */ |
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| 436 | return state->mode == GZ_READ ? |
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| 437 | (state->eof && state->strm.avail_in == 0 && state->have == 0) : 0; |
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| 438 | } |
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| 439 | |
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| 440 | /* -- see zlib.h -- */ |
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| 441 | const char * ZEXPORT gzerror(file, errnum) |
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| 442 | gzFile file; |
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| 443 | int *errnum; |
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| 444 | { |
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| 445 | gz_statep state; |
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| 446 | |
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| 447 | /* get internal structure and check integrity */ |
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| 448 | if (file == NULL) |
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| 449 | return NULL; |
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| 450 | state = (gz_statep)file; |
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| 451 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 452 | return NULL; |
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| 453 | |
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| 454 | /* return error information */ |
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| 455 | if (errnum != NULL) |
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| 456 | *errnum = state->err; |
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| 457 | return state->msg == NULL ? "" : state->msg; |
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| 458 | } |
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| 459 | |
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| 460 | /* -- see zlib.h -- */ |
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| 461 | void ZEXPORT gzclearerr(file) |
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| 462 | gzFile file; |
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| 463 | { |
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| 464 | gz_statep state; |
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| 465 | |
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| 466 | /* get internal structure and check integrity */ |
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| 467 | if (file == NULL) |
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| 468 | return; |
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| 469 | state = (gz_statep)file; |
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| 470 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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| 471 | return; |
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| 472 | |
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| 473 | /* clear error and end-of-file */ |
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| 474 | if (state->mode == GZ_READ) |
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| 475 | state->eof = 0; |
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| 476 | gz_error(state, Z_OK, NULL); |
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| 477 | } |
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| 478 | |
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| 479 | /* Create an error message in allocated memory and set state->err and |
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| 480 | state->msg accordingly. Free any previous error message already there. Do |
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| 481 | not try to free or allocate space if the error is Z_MEM_ERROR (out of |
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| 482 | memory). Simply save the error message as a static string. If there is an |
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| 483 | allocation failure constructing the error message, then convert the error to |
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| 484 | out of memory. */ |
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| 485 | void ZLIB_INTERNAL gz_error(state, err, msg) |
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| 486 | gz_statep state; |
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| 487 | int err; |
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| 488 | const char *msg; |
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| 489 | { |
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| 490 | /* free previously allocated message and clear */ |
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| 491 | if (state->msg != NULL) { |
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| 492 | if (state->err != Z_MEM_ERROR) |
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| 493 | free(state->msg); |
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| 494 | state->msg = NULL; |
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| 495 | } |
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| 496 | |
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| 497 | /* set error code, and if no message, then done */ |
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| 498 | state->err = err; |
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| 499 | if (msg == NULL) |
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| 500 | return; |
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| 501 | |
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| 502 | /* for an out of memory error, save as static string */ |
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| 503 | if (err == Z_MEM_ERROR) { |
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| 504 | state->msg = (char *)msg; |
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| 505 | return; |
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| 506 | } |
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| 507 | |
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| 508 | /* construct error message with path */ |
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| 509 | if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) { |
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| 510 | state->err = Z_MEM_ERROR; |
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| 511 | state->msg = (char *)"out of memory"; |
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| 512 | return; |
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| 513 | } |
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| 514 | strcpy(state->msg, state->path); |
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| 515 | strcat(state->msg, ": "); |
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| 516 | strcat(state->msg, msg); |
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| 517 | return; |
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| 518 | } |
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| 519 | |
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| 520 | #ifndef INT_MAX |
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| 521 | /* portably return maximum value for an int (when limits.h presumed not |
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| 522 | available) -- we need to do this to cover cases where 2's complement not |
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| 523 | used, since C standard permits 1's complement and sign-bit representations, |
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| 524 | otherwise we could just use ((unsigned)-1) >> 1 */ |
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| 525 | unsigned ZLIB_INTERNAL gz_intmax() |
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| 526 | { |
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| 527 | unsigned p, q; |
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| 528 | |
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| 529 | p = 1; |
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| 530 | do { |
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| 531 | q = p; |
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| 532 | p <<= 1; |
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| 533 | p++; |
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| 534 | } while (p > q); |
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| 535 | return q >> 1; |
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| 536 | } |
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| 537 | #endif |
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