compress.cc File Reference

#include "zlib.h"

Go to the source code of this file.

Macros
#define	ZLIB_INTERNAL

Functions
int ZEXPORT	compress2 (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)
int ZEXPORT	compress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
uLong ZEXPORT	compressBound (uLong sourceLen)

Macro Definition Documentation

#define ZLIB_INTERNAL

Definition at line 8 of file compress.cc.

Function Documentation

int ZEXPORT compress	(	Bytef *	dest,
		uLongf *	destLen,
		const Bytef *	source,
		uLong	sourceLen
	)

Definition at line 57 of file compress.cc.

References compress2(), and Z_DEFAULT_COMPRESSION.

{
    return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
}

int ZEXPORT compress2	(	Bytef *	dest,
		uLongf *	destLen,
		const Bytef *	source,
		uLong	sourceLen,
		int	level
	)

Definition at line 22 of file compress.cc.

References z_stream_s::avail_in, z_stream_s::avail_out, deflate(), deflateEnd(), deflateInit, z_stream_s::next_in, z_stream_s::next_out, z_stream_s::opaque, z_stream_s::total_out, Z_BUF_ERROR, Z_FINISH, Z_OK, Z_STREAM_END, z_stream_s::zalloc, and z_stream_s::zfree.

Referenced by compress().

{
    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;
}

uLong ZEXPORT compressBound

(

uLong

sourceLen

)

Definition at line 66 of file compress.cc.

{
    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
           (sourceLen >> 25) + 13;
}