| 1 | /* uncompr.c -- decompress a memory buffer |
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| 2 | * Copyright (C) 1995-2003 Jean-loup Gailly. |
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| 3 | * For conditions of distribution and use, see copyright notice in zlib.h |
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| 4 | */ |
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| 5 | |
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| 6 | /* @(#) $Id$ */ |
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| 7 | |
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| 8 | #define ZLIB_INTERNAL |
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| 9 | #include "zlib.h" |
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| 10 | |
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| 11 | /* =========================================================================== |
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| 12 | Decompresses the source buffer into the destination buffer. sourceLen is |
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| 13 | the byte length of the source buffer. Upon entry, destLen is the total |
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| 14 | size of the destination buffer, which must be large enough to hold the |
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| 15 | entire uncompressed data. (The size of the uncompressed data must have |
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| 16 | been saved previously by the compressor and transmitted to the decompressor |
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| 17 | by some mechanism outside the scope of this compression library.) |
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| 18 | Upon exit, destLen is the actual size of the compressed buffer. |
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| 19 | This function can be used to decompress a whole file at once if the |
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| 20 | input file is mmap'ed. |
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| 21 | |
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| 22 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not |
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| 23 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
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| 24 | buffer, or Z_DATA_ERROR if the input data was corrupted. |
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| 25 | */ |
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| 26 | int ZEXPORT uncompress (dest, destLen, source, sourceLen) |
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| 27 | Bytef *dest; |
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| 28 | uLongf *destLen; |
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| 29 | const Bytef *source; |
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| 30 | uLong sourceLen; |
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| 31 | { |
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| 32 | z_stream stream; |
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| 33 | int err; |
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| 34 | |
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| 35 | stream.next_in = (Bytef*)source; |
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| 36 | stream.avail_in = (uInt)sourceLen; |
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| 37 | /* Check for source > 64K on 16-bit machine: */ |
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| 38 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
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| 39 | |
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| 40 | stream.next_out = dest; |
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| 41 | stream.avail_out = (uInt)*destLen; |
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| 42 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
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| 43 | |
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| 44 | stream.zalloc = (alloc_func)0; |
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| 45 | stream.zfree = (free_func)0; |
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| 46 | |
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| 47 | err = inflateInit(&stream); |
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| 48 | if (err != Z_OK) return err; |
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| 49 | |
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| 50 | err = inflate(&stream, Z_FINISH); |
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| 51 | if (err != Z_STREAM_END) { |
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| 52 | inflateEnd(&stream); |
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| 53 | if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)) |
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| 54 | return Z_DATA_ERROR; |
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| 55 | return err; |
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| 56 | } |
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| 57 | *destLen = stream.total_out; |
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| 58 | |
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| 59 | err = inflateEnd(&stream); |
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| 60 | return err; |
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| 61 | } |
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