Chris@4: /* compress.c -- compress a memory buffer
Chris@4:  * Copyright (C) 1995-2005 Jean-loup Gailly.
Chris@4:  * For conditions of distribution and use, see copyright notice in zlib.h
Chris@4:  */
Chris@4: 
Chris@4: /* @(#) $Id$ */
Chris@4: 
Chris@4: #define ZLIB_INTERNAL
Chris@4: #include "zlib.h"
Chris@4: 
Chris@4: /* ===========================================================================
Chris@4:      Compresses the source buffer into the destination buffer. The level
Chris@4:    parameter has the same meaning as in deflateInit.  sourceLen is the byte
Chris@4:    length of the source buffer. Upon entry, destLen is the total size of the
Chris@4:    destination buffer, which must be at least 0.1% larger than sourceLen plus
Chris@4:    12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
Chris@4: 
Chris@4:      compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
Chris@4:    memory, Z_BUF_ERROR if there was not enough room in the output buffer,
Chris@4:    Z_STREAM_ERROR if the level parameter is invalid.
Chris@4: */
Chris@4: int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
Chris@4:     Bytef *dest;
Chris@4:     uLongf *destLen;
Chris@4:     const Bytef *source;
Chris@4:     uLong sourceLen;
Chris@4:     int level;
Chris@4: {
Chris@4:     z_stream stream;
Chris@4:     int err;
Chris@4: 
Chris@4:     stream.next_in = (Bytef*)source;
Chris@4:     stream.avail_in = (uInt)sourceLen;
Chris@4: #ifdef MAXSEG_64K
Chris@4:     /* Check for source > 64K on 16-bit machine: */
Chris@4:     if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
Chris@4: #endif
Chris@4:     stream.next_out = dest;
Chris@4:     stream.avail_out = (uInt)*destLen;
Chris@4:     if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
Chris@4: 
Chris@4:     stream.zalloc = (alloc_func)0;
Chris@4:     stream.zfree = (free_func)0;
Chris@4:     stream.opaque = (voidpf)0;
Chris@4: 
Chris@4:     err = deflateInit(&stream, level);
Chris@4:     if (err != Z_OK) return err;
Chris@4: 
Chris@4:     err = deflate(&stream, Z_FINISH);
Chris@4:     if (err != Z_STREAM_END) {
Chris@4:         deflateEnd(&stream);
Chris@4:         return err == Z_OK ? Z_BUF_ERROR : err;
Chris@4:     }
Chris@4:     *destLen = stream.total_out;
Chris@4: 
Chris@4:     err = deflateEnd(&stream);
Chris@4:     return err;
Chris@4: }
Chris@4: 
Chris@4: /* ===========================================================================
Chris@4:  */
Chris@4: int ZEXPORT compress (dest, destLen, source, sourceLen)
Chris@4:     Bytef *dest;
Chris@4:     uLongf *destLen;
Chris@4:     const Bytef *source;
Chris@4:     uLong sourceLen;
Chris@4: {
Chris@4:     return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
Chris@4: }
Chris@4: 
Chris@4: /* ===========================================================================
Chris@4:      If the default memLevel or windowBits for deflateInit() is changed, then
Chris@4:    this function needs to be updated.
Chris@4:  */
Chris@4: uLong ZEXPORT compressBound (sourceLen)
Chris@4:     uLong sourceLen;
Chris@4: {
Chris@4:     return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
Chris@4:            (sourceLen >> 25) + 13;
Chris@4: }