mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-14 11:33:46 +00:00
76 lines
2.5 KiB
C
76 lines
2.5 KiB
C
/* uncompr.c -- decompress a memory buffer
|
|
* Copyright (C) 1995-2003, 2010, 2014 Jean-loup Gailly, Mark Adler.
|
|
* For conditions of distribution and use, see copyright notice in zlib.h
|
|
*/
|
|
|
|
/* @(#) $Id$ */
|
|
|
|
#define ZLIB_INTERNAL
|
|
#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.
|
|
|
|
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, including if the
|
|
input data is an incomplete zlib stream.
|
|
*/
|
|
int ZEXPORT uncompress(unsigned char *dest, size_t *destLen, const unsigned char *source, size_t sourceLen) {
|
|
z_stream stream;
|
|
int err;
|
|
const unsigned int max = (unsigned int)0 - 1;
|
|
size_t left;
|
|
unsigned char buf[1]; /* for detection of incomplete stream when *destLen == 0 */
|
|
|
|
if (*destLen) {
|
|
left = *destLen;
|
|
*destLen = 0;
|
|
}
|
|
else {
|
|
left = 1;
|
|
dest = buf;
|
|
}
|
|
|
|
stream.next_in = (const unsigned char *)source;
|
|
stream.avail_in = 0;
|
|
stream.zalloc = (alloc_func)0;
|
|
stream.zfree = (free_func)0;
|
|
stream.opaque = NULL;
|
|
|
|
err = inflateInit(&stream);
|
|
if (err != Z_OK) return err;
|
|
|
|
stream.next_out = dest;
|
|
stream.avail_out = 0;
|
|
|
|
do {
|
|
if (stream.avail_out == 0) {
|
|
stream.avail_out = left > (unsigned long)max ? max : (unsigned int)left;
|
|
left -= stream.avail_out;
|
|
}
|
|
if (stream.avail_in == 0) {
|
|
stream.avail_in = sourceLen > (unsigned long)max ? max : (unsigned int)sourceLen;
|
|
sourceLen -= stream.avail_in;
|
|
}
|
|
err = inflate(&stream, Z_NO_FLUSH);
|
|
} while (err == Z_OK);
|
|
|
|
if (dest != buf)
|
|
*destLen = stream.total_out;
|
|
else if (stream.total_out && err == Z_BUF_ERROR)
|
|
left = 1;
|
|
|
|
inflateEnd(&stream);
|
|
return err == Z_STREAM_END ? Z_OK :
|
|
err == Z_NEED_DICT ? Z_DATA_ERROR :
|
|
err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
|
|
err;
|
|
}
|