iw7-mod/deps/zstd/examples/streaming_memory_usage.c
2024-08-13 05:15:34 -04:00

138 lines
5.7 KiB
C

/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
/*=== Tuning parameter ===*/
#ifndef MAX_TESTED_LEVEL
#define MAX_TESTED_LEVEL 12
#endif
/*=== Dependencies ===*/
#include <stdio.h> // printf
#define ZSTD_STATIC_LINKING_ONLY
#include <zstd.h> // presumes zstd library is installed
#include "common.h" // Helper functions, CHECK(), and CHECK_ZSTD()
/*=== functions ===*/
/*! readU32FromChar() :
@return : unsigned integer value read from input in `char` format
allows and interprets K, KB, KiB, M, MB and MiB suffix.
Will also modify `*stringPtr`, advancing it to position where it stopped reading.
Note : function result can overflow if digit string > MAX_UINT */
static unsigned readU32FromChar(const char** stringPtr)
{
unsigned result = 0;
while ((**stringPtr >='0') && (**stringPtr <='9'))
result *= 10, result += **stringPtr - '0', (*stringPtr)++ ;
if ((**stringPtr=='K') || (**stringPtr=='M')) {
result <<= 10;
if (**stringPtr=='M') result <<= 10;
(*stringPtr)++ ;
if (**stringPtr=='i') (*stringPtr)++;
if (**stringPtr=='B') (*stringPtr)++;
}
return result;
}
int main(int argc, char const *argv[]) {
printf("\n Zstandard (v%s) memory usage for streaming : \n\n", ZSTD_versionString());
unsigned wLog = 0;
if (argc > 1) {
const char* valStr = argv[1];
wLog = readU32FromChar(&valStr);
}
int compressionLevel;
for (compressionLevel = 1; compressionLevel <= MAX_TESTED_LEVEL; compressionLevel++) {
#define INPUT_SIZE 5
#define COMPRESSED_SIZE 128
char const dataToCompress[INPUT_SIZE] = "abcde";
char compressedData[COMPRESSED_SIZE];
char decompressedData[INPUT_SIZE];
/* the ZSTD_CCtx_params structure is a way to save parameters and use
* them across multiple contexts. We use them here so we can call the
* function ZSTD_estimateCStreamSize_usingCCtxParams().
*/
ZSTD_CCtx_params* const cctxParams = ZSTD_createCCtxParams();
CHECK(cctxParams != NULL, "ZSTD_createCCtxParams() failed!");
/* Set the compression level. */
CHECK_ZSTD( ZSTD_CCtxParams_setParameter(cctxParams, ZSTD_c_compressionLevel, compressionLevel) );
/* Set the window log.
* The value 0 means use the default window log, which is equivalent to
* not setting it.
*/
CHECK_ZSTD( ZSTD_CCtxParams_setParameter(cctxParams, ZSTD_c_windowLog, wLog) );
/* Force the compressor to allocate the maximum memory size for a given
* level by not providing the pledged source size, or calling
* ZSTD_compressStream2() with ZSTD_e_end.
*/
ZSTD_CCtx* const cctx = ZSTD_createCCtx();
CHECK(cctx != NULL, "ZSTD_createCCtx() failed!");
CHECK_ZSTD( ZSTD_CCtx_setParametersUsingCCtxParams(cctx, cctxParams) );
size_t compressedSize;
{
ZSTD_inBuffer inBuff = { dataToCompress, sizeof(dataToCompress), 0 };
ZSTD_outBuffer outBuff = { compressedData, sizeof(compressedData), 0 };
CHECK_ZSTD( ZSTD_compressStream(cctx, &outBuff, &inBuff) );
size_t const remaining = ZSTD_endStream(cctx, &outBuff);
CHECK_ZSTD(remaining);
CHECK(remaining == 0, "Frame not flushed!");
compressedSize = outBuff.pos;
}
ZSTD_DCtx* const dctx = ZSTD_createDCtx();
CHECK(dctx != NULL, "ZSTD_createDCtx() failed!");
/* Set the maximum allowed window log.
* The value 0 means use the default window log, which is equivalent to
* not setting it.
*/
CHECK_ZSTD( ZSTD_DCtx_setParameter(dctx, ZSTD_d_windowLogMax, wLog) );
/* forces decompressor to use maximum memory size, since the
* decompressed size is not stored in the frame header.
*/
{ ZSTD_inBuffer inBuff = { compressedData, compressedSize, 0 };
ZSTD_outBuffer outBuff = { decompressedData, sizeof(decompressedData), 0 };
size_t const remaining = ZSTD_decompressStream(dctx, &outBuff, &inBuff);
CHECK_ZSTD(remaining);
CHECK(remaining == 0, "Frame not complete!");
CHECK(outBuff.pos == sizeof(dataToCompress), "Bad decompression!");
}
size_t const cstreamSize = ZSTD_sizeof_CStream(cctx);
size_t const cstreamEstimatedSize = ZSTD_estimateCStreamSize_usingCCtxParams(cctxParams);
size_t const dstreamSize = ZSTD_sizeof_DStream(dctx);
size_t const dstreamEstimatedSize = ZSTD_estimateDStreamSize_fromFrame(compressedData, compressedSize);
CHECK(cstreamSize <= cstreamEstimatedSize, "Compression mem (%u) > estimated (%u)",
(unsigned)cstreamSize, (unsigned)cstreamEstimatedSize);
CHECK(dstreamSize <= dstreamEstimatedSize, "Decompression mem (%u) > estimated (%u)",
(unsigned)dstreamSize, (unsigned)dstreamEstimatedSize);
printf("Level %2i : Compression Mem = %5u KB (estimated : %5u KB) ; Decompression Mem = %4u KB (estimated : %5u KB)\n",
compressionLevel,
(unsigned)(cstreamSize>>10), (unsigned)(cstreamEstimatedSize>>10),
(unsigned)(dstreamSize>>10), (unsigned)(dstreamEstimatedSize>>10));
ZSTD_freeDCtx(dctx);
ZSTD_freeCCtx(cctx);
ZSTD_freeCCtxParams(cctxParams);
if (wLog) break; /* single test */
}
return 0;
}