| 1 | /* compress.c -- compress a memory buffer
|
|---|
| 2 | * Copyright (C) 1995-2003 Jean-loup Gailly.
|
|---|
| 3 | * For conditions of distribution and use, see copyright notice in zlib.h
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /* @(#) $Id$ */
|
|---|
| 7 |
|
|---|
| 8 | #include "zutil.h"
|
|---|
| 9 |
|
|---|
| 10 | /* ===========================================================================
|
|---|
| 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 | */
|
|---|
| 21 | int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
|
|---|
| 22 | Bytef *dest;
|
|---|
| 23 | uLongf *destLen;
|
|---|
| 24 | const Bytef *source;
|
|---|
| 25 | uLong sourceLen;
|
|---|
| 26 | int level;
|
|---|
| 27 | {
|
|---|
| 28 | z_stream stream;
|
|---|
| 29 | int err;
|
|---|
| 30 |
|
|---|
| 31 | stream.next_in = 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 |
|
|---|
| 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 | }
|
|---|
| 58 |
|
|---|
| 59 | /* ===========================================================================
|
|---|
| 60 | */
|
|---|
| 61 | int 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 | }
|
|---|
| 69 |
|
|---|
| 70 | /* ===========================================================================
|
|---|
| 71 | If the default memLevel or windowBits for deflateInit() is changed, then
|
|---|
| 72 | this function needs to be updated.
|
|---|
| 73 | */
|
|---|
| 74 | uLong ZEXPORT compressBound (sourceLen)
|
|---|
| 75 | uLong sourceLen;
|
|---|
| 76 | {
|
|---|
| 77 | return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
|
|---|
| 78 | }
|
|---|
