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1 /* compress.c -- compress a memory buffer | 1 /* compress.c -- compress a memory buffer |
2 * Copyright (C) 1995-2005 Jean-loup Gailly. | 2 * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler |
3 * For conditions of distribution and use, see copyright notice in zlib.h | 3 * For conditions of distribution and use, see copyright notice in zlib.h |
4 */ | 4 */ |
5 | 5 |
6 /* @(#) $Id$ */ | 6 /* @(#) $Id$ */ |
7 | 7 |
8 #define ZLIB_INTERNAL | 8 #define ZLIB_INTERNAL |
9 #include "zlib.h" | 9 #include "zlib.h" |
10 | 10 |
11 /* =========================================================================== | 11 /* =========================================================================== |
12 Compresses the source buffer into the destination buffer. The level | 12 Compresses the source buffer into the destination buffer. The level |
13 parameter has the same meaning as in deflateInit. sourceLen is the byte | 13 parameter has the same meaning as in deflateInit. sourceLen is the byte |
14 length of the source buffer. Upon entry, destLen is the total size of the | 14 length of the source buffer. Upon entry, destLen is the total size of the |
15 destination buffer, which must be at least 0.1% larger than sourceLen plus | 15 destination buffer, which must be at least 0.1% larger than sourceLen plus |
16 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. | 16 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
17 | 17 |
18 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 18 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
19 memory, Z_BUF_ERROR if there was not enough room in the output buffer, | 19 memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
20 Z_STREAM_ERROR if the level parameter is invalid. | 20 Z_STREAM_ERROR if the level parameter is invalid. |
21 */ | 21 */ |
22 int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) | 22 int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) |
23 Bytef *dest; | 23 Bytef *dest; |
24 uLongf *destLen; | 24 uLongf *destLen; |
25 const Bytef *source; | 25 const Bytef *source; |
26 uLong sourceLen; | 26 uLong sourceLen; |
27 int level; | 27 int level; |
28 { | 28 { |
29 z_stream stream; | 29 z_stream stream; |
30 int err; | 30 int err; |
| 31 const uInt max = (uInt)-1; |
| 32 uLong left; |
31 | 33 |
32 stream.next_in = (z_const Bytef *)source; | 34 left = *destLen; |
33 stream.avail_in = (uInt)sourceLen; | 35 *destLen = 0; |
34 #ifdef MAXSEG_64K | |
35 /* Check for source > 64K on 16-bit machine: */ | |
36 if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; | |
37 #endif | |
38 stream.next_out = dest; | |
39 stream.avail_out = (uInt)*destLen; | |
40 if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; | |
41 | 36 |
42 stream.zalloc = (alloc_func)0; | 37 stream.zalloc = (alloc_func)0; |
43 stream.zfree = (free_func)0; | 38 stream.zfree = (free_func)0; |
44 stream.opaque = (voidpf)0; | 39 stream.opaque = (voidpf)0; |
45 | 40 |
46 err = deflateInit(&stream, level); | 41 err = deflateInit(&stream, level); |
47 if (err != Z_OK) return err; | 42 if (err != Z_OK) return err; |
48 | 43 |
49 err = deflate(&stream, Z_FINISH); | 44 stream.next_out = dest; |
50 if (err != Z_STREAM_END) { | 45 stream.avail_out = 0; |
51 deflateEnd(&stream); | 46 stream.next_in = (z_const Bytef *)source; |
52 return err == Z_OK ? Z_BUF_ERROR : err; | 47 stream.avail_in = 0; |
53 } | 48 |
| 49 do { |
| 50 if (stream.avail_out == 0) { |
| 51 stream.avail_out = left > (uLong)max ? max : (uInt)left; |
| 52 left -= stream.avail_out; |
| 53 } |
| 54 if (stream.avail_in == 0) { |
| 55 stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen; |
| 56 sourceLen -= stream.avail_in; |
| 57 } |
| 58 err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH); |
| 59 } while (err == Z_OK); |
| 60 |
54 *destLen = stream.total_out; | 61 *destLen = stream.total_out; |
55 | 62 deflateEnd(&stream); |
56 err = deflateEnd(&stream); | 63 return err == Z_STREAM_END ? Z_OK : err; |
57 return err; | |
58 } | 64 } |
59 | 65 |
60 /* =========================================================================== | 66 /* =========================================================================== |
61 */ | 67 */ |
62 int ZEXPORT compress (dest, destLen, source, sourceLen) | 68 int ZEXPORT compress (dest, destLen, source, sourceLen) |
63 Bytef *dest; | 69 Bytef *dest; |
64 uLongf *destLen; | 70 uLongf *destLen; |
65 const Bytef *source; | 71 const Bytef *source; |
66 uLong sourceLen; | 72 uLong sourceLen; |
67 { | 73 { |
68 return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); | 74 return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
69 } | 75 } |
70 | 76 |
71 /* =========================================================================== | 77 /* =========================================================================== |
72 If the default memLevel or windowBits for deflateInit() is changed, then | 78 If the default memLevel or windowBits for deflateInit() is changed, then |
73 this function needs to be updated. | 79 this function needs to be updated. |
74 */ | 80 */ |
75 uLong ZEXPORT compressBound (sourceLen) | 81 uLong ZEXPORT compressBound (sourceLen) |
76 uLong sourceLen; | 82 uLong sourceLen; |
77 { | 83 { |
78 return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + | 84 return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
79 (sourceLen >> 25) + 13; | 85 (sourceLen >> 25) + 13; |
80 } | 86 } |
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