1/* compress.c -- compress a memory buffer
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2 * Copyright (C) 1995-1996 Jean-loup Gailly.
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2 * Copyright (C) 1995-1998 Jean-loup Gailly. |
3 * For conditions of distribution and use, see copyright notice in zlib.h 4 */ 5
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6/* $FreeBSD: head/lib/libz/compress.c 21673 1997-01-14 07:20:47Z jkh $ */
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6/* $FreeBSD: head/lib/libz/compress.c 33908 1998-02-28 06:08:17Z steve $ */ |
7 8#include "zlib.h" 9 10/* ===========================================================================
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11 Compresses the source buffer into the destination buffer. sourceLen is
12 the byte length of the source buffer. Upon entry, destLen is the total
13 size of the destination buffer, which must be at least 0.1% larger than
14 sourceLen plus 8 bytes. Upon exit, destLen is the actual size of the
15 compressed buffer.
16 This function can be used to compress a whole file at once if the
17 input file is mmap'ed.
18 compress returns Z_OK if success, Z_MEM_ERROR if there was not
19 enough memory, Z_BUF_ERROR if there was not enough room in the output
20 buffer.
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11 Compresses the source buffer into the destination buffer. The level 12 parameter has the same meaning as in deflateInit. sourceLen is the byte 13 length of the source buffer. Upon entry, destLen is the total size of the 14 destination buffer, which must be at least 0.1% larger than sourceLen plus 15 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. 16 17 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 18 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 19 Z_STREAM_ERROR if the level parameter is invalid. |
20*/
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22int compress (dest, destLen, source, sourceLen)
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21int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) |
22 Bytef *dest; 23 uLongf *destLen; 24 const Bytef *source; 25 uLong sourceLen;
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26 int level; |
27{ 28 z_stream stream; 29 int err; 30 31 stream.next_in = (Bytef*)source; 32 stream.avail_in = (uInt)sourceLen; 33#ifdef MAXSEG_64K 34 /* Check for source > 64K on 16-bit machine: */ 35 if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; 36#endif 37 stream.next_out = dest; 38 stream.avail_out = (uInt)*destLen; 39 if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; 40 41 stream.zalloc = (alloc_func)0; 42 stream.zfree = (free_func)0; 43 stream.opaque = (voidpf)0; 44
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45 err = deflateInit(&stream, Z_DEFAULT_COMPRESSION);
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45 err = deflateInit(&stream, level); |
46 if (err != Z_OK) return err; 47 48 err = deflate(&stream, Z_FINISH); 49 if (err != Z_STREAM_END) { 50 deflateEnd(&stream); 51 return err == Z_OK ? Z_BUF_ERROR : err; 52 } 53 *destLen = stream.total_out; 54 55 err = deflateEnd(&stream); 56 return err; 57}
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58 59/* =========================================================================== 60 */ 61int ZEXPORT compress (dest, destLen, source, sourceLen) 62 Bytef *dest; 63 uLongf *destLen; 64 const Bytef *source; 65 uLong sourceLen; 66{ 67 return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); 68} |
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