uncompr.c
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上传日期:2013-07-19
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- /* uncompr.c -- decompress a memory buffer
- * Copyright (C) 1995-2002 Jean-loup Gailly.
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- /* @(#) $Id: uncompr.c,v 1.1.1.1 2002/10/18 01:43:41 ping Exp $ */
- #include "zlib.h"
- /* ===========================================================================
- Decompresses the source buffer into the destination buffer. sourceLen is
- the byte length of the source buffer. Upon entry, destLen is the total
- size of the destination buffer, which must be large enough to hold the
- entire uncompressed data. (The size of the uncompressed data must have
- been saved previously by the compressor and transmitted to the decompressor
- by some mechanism outside the scope of this compression library.)
- Upon exit, destLen is the actual size of the compressed buffer.
- This function can be used to decompress a whole file at once if the
- input file is mmap'ed.
- uncompress 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, or Z_DATA_ERROR if the input data was corrupted.
- */
- int ZEXPORT uncompress (dest, destLen, source, sourceLen)
- Bytef *dest;
- uLongf *destLen;
- const Bytef *source;
- uLong sourceLen;
- {
- z_stream stream;
- int err;
- stream.next_in = (Bytef*)source;
- stream.avail_in = (uInt)sourceLen;
- /* Check for source > 64K on 16-bit machine: */
- if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
- 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;
- err = inflateInit(&stream);
- if (err != Z_OK) return err;
- err = inflate(&stream, Z_FINISH);
- if (err != Z_STREAM_END) {
- inflateEnd(&stream);
- return err == Z_OK ? Z_BUF_ERROR : err;
- }
- *destLen = stream.total_out;
- err = inflateEnd(&stream);
- return err;
- }