167 lines
4.7 KiB
C
167 lines
4.7 KiB
C
/*
|
|
* Copyright © 2021 Valve Corporation
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice (including the next
|
|
* paragraph) shall be included in all copies or substantial portions of the
|
|
* Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
* IN THE SOFTWARE.
|
|
*/
|
|
|
|
#ifdef HAVE_COMPRESSION
|
|
|
|
#include <assert.h>
|
|
|
|
/* Ensure that zlib uses 'const' in 'z_const' declarations. */
|
|
#ifndef ZLIB_CONST
|
|
#define ZLIB_CONST
|
|
#endif
|
|
|
|
#ifdef HAVE_ZLIB
|
|
#include "zlib.h"
|
|
#endif
|
|
|
|
#ifdef HAVE_ZSTD
|
|
#include "zstd.h"
|
|
#endif
|
|
|
|
#include "util/compress.h"
|
|
#include "macros.h"
|
|
|
|
/* 3 is the recomended level, with 22 as the absolute maximum */
|
|
#define ZSTD_COMPRESSION_LEVEL 3
|
|
|
|
size_t
|
|
util_compress_max_compressed_len(size_t in_data_size)
|
|
{
|
|
#ifdef HAVE_ZSTD
|
|
/* from the zstd docs (https://facebook.github.io/zstd/zstd_manual.html):
|
|
* compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
|
|
*/
|
|
return ZSTD_compressBound(in_data_size);
|
|
#elif defined(HAVE_ZLIB)
|
|
/* From https://zlib.net/zlib_tech.html:
|
|
*
|
|
* "In the worst possible case, where the other block types would expand
|
|
* the data, deflation falls back to stored (uncompressed) blocks. Thus
|
|
* for the default settings used by deflateInit(), compress(), and
|
|
* compress2(), the only expansion is an overhead of five bytes per 16 KB
|
|
* block (about 0.03%), plus a one-time overhead of six bytes for the
|
|
* entire stream."
|
|
*/
|
|
size_t num_blocks = (in_data_size + 16383) / 16384; /* round up blocks */
|
|
return in_data_size + 6 + (num_blocks * 5);
|
|
#else
|
|
STATIC_ASSERT(false);
|
|
#endif
|
|
}
|
|
|
|
/* Compress data and return the size of the compressed data */
|
|
size_t
|
|
util_compress_deflate(const uint8_t *in_data, size_t in_data_size,
|
|
uint8_t *out_data, size_t out_buff_size)
|
|
{
|
|
#ifdef HAVE_ZSTD
|
|
size_t ret = ZSTD_compress(out_data, out_buff_size, in_data, in_data_size,
|
|
ZSTD_COMPRESSION_LEVEL);
|
|
if (ZSTD_isError(ret))
|
|
return 0;
|
|
|
|
return ret;
|
|
#elif defined(HAVE_ZLIB)
|
|
size_t compressed_size = 0;
|
|
|
|
/* allocate deflate state */
|
|
z_stream strm;
|
|
strm.zalloc = Z_NULL;
|
|
strm.zfree = Z_NULL;
|
|
strm.opaque = Z_NULL;
|
|
strm.next_in = in_data;
|
|
strm.next_out = out_data;
|
|
strm.avail_in = in_data_size;
|
|
strm.avail_out = out_buff_size;
|
|
|
|
int ret = deflateInit(&strm, Z_BEST_COMPRESSION);
|
|
if (ret != Z_OK) {
|
|
(void) deflateEnd(&strm);
|
|
return 0;
|
|
}
|
|
|
|
/* compress until end of in_data */
|
|
ret = deflate(&strm, Z_FINISH);
|
|
|
|
/* stream should be complete */
|
|
assert(ret == Z_STREAM_END);
|
|
if (ret == Z_STREAM_END) {
|
|
compressed_size = strm.total_out;
|
|
}
|
|
|
|
/* clean up and return */
|
|
(void) deflateEnd(&strm);
|
|
return compressed_size;
|
|
#else
|
|
STATIC_ASSERT(false);
|
|
# endif
|
|
}
|
|
|
|
/**
|
|
* Decompresses data, returns true if successful.
|
|
*/
|
|
bool
|
|
util_compress_inflate(const uint8_t *in_data, size_t in_data_size,
|
|
uint8_t *out_data, size_t out_data_size)
|
|
{
|
|
#ifdef HAVE_ZSTD
|
|
size_t ret = ZSTD_decompress(out_data, out_data_size, in_data, in_data_size);
|
|
return !ZSTD_isError(ret);
|
|
#elif defined(HAVE_ZLIB)
|
|
z_stream strm;
|
|
|
|
/* allocate inflate state */
|
|
strm.zalloc = Z_NULL;
|
|
strm.zfree = Z_NULL;
|
|
strm.opaque = Z_NULL;
|
|
strm.next_in = in_data;
|
|
strm.avail_in = in_data_size;
|
|
strm.next_out = out_data;
|
|
strm.avail_out = out_data_size;
|
|
|
|
int ret = inflateInit(&strm);
|
|
if (ret != Z_OK)
|
|
return false;
|
|
|
|
ret = inflate(&strm, Z_NO_FLUSH);
|
|
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
|
|
|
|
/* Unless there was an error we should have decompressed everything in one
|
|
* go as we know the uncompressed file size.
|
|
*/
|
|
if (ret != Z_STREAM_END) {
|
|
(void)inflateEnd(&strm);
|
|
return false;
|
|
}
|
|
assert(strm.avail_out == 0);
|
|
|
|
/* clean up and return */
|
|
(void)inflateEnd(&strm);
|
|
return true;
|
|
#else
|
|
STATIC_ASSERT(false);
|
|
#endif
|
|
}
|
|
|
|
#endif
|