| [1] | 1 | /* compress.c -- compress 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 | Compresses the source buffer into the destination buffer. The level |
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| 13 | parameter has the same meaning as in deflateInit. sourceLen is the byte |
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| 14 | length of the source buffer. Upon entry, destLen is the total size of the |
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| 15 | destination buffer, which must be at least 0.1% larger than sourceLen plus |
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| 16 | 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
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| 17 | |
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| 18 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
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| 19 | memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
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| 20 | Z_STREAM_ERROR if the level parameter is invalid. |
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| 21 | */ |
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| 22 | int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) |
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| 23 | Bytef *dest; |
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| 24 | uLongf *destLen; |
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| 25 | const Bytef *source; |
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| 26 | uLong sourceLen; |
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| 27 | int level; |
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| 28 | { |
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| 29 | z_stream stream; |
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| 30 | int err; |
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| 31 | |
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| 32 | stream.next_in = (Bytef*)source; |
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| 33 | stream.avail_in = (uInt)sourceLen; |
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| 34 | #ifdef MAXSEG_64K |
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| 35 | /* Check for source > 64K on 16-bit machine: */ |
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| 36 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
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| 37 | #endif |
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| 38 | stream.next_out = dest; |
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| 39 | stream.avail_out = (uInt)*destLen; |
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| 40 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
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| 41 | |
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| 42 | stream.zalloc = (alloc_func)0; |
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| 43 | stream.zfree = (free_func)0; |
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| 44 | stream.opaque = (voidpf)0; |
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| 45 | |
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| 46 | err = deflateInit(&stream, level); |
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| 47 | if (err != Z_OK) return err; |
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| 48 | |
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| 49 | err = deflate(&stream, Z_FINISH); |
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| 50 | if (err != Z_STREAM_END) { |
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| 51 | deflateEnd(&stream); |
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| 52 | return err == Z_OK ? Z_BUF_ERROR : err; |
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| 53 | } |
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| 54 | *destLen = stream.total_out; |
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| 55 | |
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| 56 | err = deflateEnd(&stream); |
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| 57 | return err; |
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| 58 | } |
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| 59 | |
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| 60 | /* =========================================================================== |
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| 61 | */ |
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| 62 | int ZEXPORT compress (dest, destLen, source, sourceLen) |
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| 63 | Bytef *dest; |
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| 64 | uLongf *destLen; |
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| 65 | const Bytef *source; |
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| 66 | uLong sourceLen; |
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| 67 | { |
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| 68 | return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
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| 69 | } |
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| 70 | |
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| 71 | /* =========================================================================== |
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| 72 | If the default memLevel or windowBits for deflateInit() is changed, then |
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| 73 | this function needs to be updated. |
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| 74 | */ |
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| 75 | uLong ZEXPORT compressBound (sourceLen) |
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| 76 | uLong sourceLen; |
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| 77 | { |
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| 78 | return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11; |
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| 79 | } |
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