src/zlib/compress.c

/* compress.c -- compress a memory buffer
 * Copyright (C) 1995-1998 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* @(#) $Id$ */

#include "../zlib/zlib.h"

/* ===========================================================================
     Compresses the source buffer into the destination buffer. The level
   parameter has the same meaning as in deflateInit.  sourceLen is the byte
   length of the source buffer. Upon entry, destLen is the total size of the
   destination buffer, which must be at least 0.1% larger than sourceLen plus
   12 bytes. Upon exit, destLen is the actual size of the compressed buffer.

     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
   Z_STREAM_ERROR if the level parameter is invalid.
*/
int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
    Bytef *dest;
    uLongf *destLen;
    const Bytef *source;
    uLong sourceLen;
    int level;
{
    z_stream stream;
    int err;

    stream.next_in = (Bytef*)source;
    stream.avail_in = (uInt)sourceLen;
#ifdef MAXSEG_64K
    /* Check for source > 64K on 16-bit machine: */
    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
#endif
    stream.next_out = dest;
    stream.avail_out = (uInt)*destLen;
    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;

    stream.zalloc = (alloc_func)0;
    stream.zfree = (free_func)0;
    stream.opaque = (voidpf)0;

    err = deflateInit(&stream, level);
    if (err != Z_OK) return err;

    err = deflate(&stream, Z_FINISH);
    if (err != Z_STREAM_END) {
        deflateEnd(&stream);
        return err == Z_OK ? Z_BUF_ERROR : err;
    }
    *destLen = stream.total_out;

    err = deflateEnd(&stream);
    return err;
}

/* ===========================================================================
 */
int ZEXPORT compress (dest, destLen, source, sourceLen)
    Bytef *dest;
    uLongf *destLen;
    const Bytef *source;
    uLong sourceLen;
{
    return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
}
Commit	Line	Data
	1	/* compress.c -- compress a memory buffer
	2	* Copyright (C) 1995-1998 Jean-loup Gailly.
	3	* For conditions of distribution and use, see copyright notice in zlib.h
	4	*/
	5
	6	/* @(#) $Id$ */
	7
	8	#include "../zlib/zlib.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 = (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
	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	}