108 lines
3.5 KiB
C
108 lines
3.5 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.
|
||
|
|
**/
|
||
|
|
|
||
|
|
/* This example deals with Dictionary compression,
|
||
|
|
* its counterpart is `examples/dictionary_decompression.c` .
|
||
|
|
* These examples presume that a dictionary already exists.
|
||
|
|
* The main method to create a dictionary is `zstd --train`,
|
||
|
|
* look at the CLI documentation for details.
|
||
|
|
* Another possible method is to employ dictionary training API,
|
||
|
|
* published in `lib/zdict.h` .
|
||
|
|
**/
|
||
|
|
|
||
|
|
#include <stdio.h> // printf
|
||
|
|
#include <stdlib.h> // free
|
||
|
|
#include <string.h> // memset, strcat
|
||
|
|
#include <zstd.h> // presumes zstd library is installed
|
||
|
|
#include "common.h" // Helper functions, CHECK(), and CHECK_ZSTD()
|
||
|
|
|
||
|
|
/* createDict() :
|
||
|
|
** `dictFileName` is supposed already created using `zstd --train` */
|
||
|
|
static ZSTD_CDict* createCDict_orDie(const char* dictFileName, int cLevel)
|
||
|
|
{
|
||
|
|
size_t dictSize;
|
||
|
|
printf("loading dictionary %s \n", dictFileName);
|
||
|
|
void* const dictBuffer = mallocAndLoadFile_orDie(dictFileName, &dictSize);
|
||
|
|
ZSTD_CDict* const cdict = ZSTD_createCDict(dictBuffer, dictSize, cLevel);
|
||
|
|
CHECK(cdict != NULL, "ZSTD_createCDict() failed!");
|
||
|
|
free(dictBuffer);
|
||
|
|
return cdict;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
static void compress(const char* fname, const char* oname, const ZSTD_CDict* cdict)
|
||
|
|
{
|
||
|
|
size_t fSize;
|
||
|
|
void* const fBuff = mallocAndLoadFile_orDie(fname, &fSize);
|
||
|
|
size_t const cBuffSize = ZSTD_compressBound(fSize);
|
||
|
|
void* const cBuff = malloc_orDie(cBuffSize);
|
||
|
|
|
||
|
|
/* Compress using the dictionary.
|
||
|
|
* This function writes the dictionary id, and content size into the header.
|
||
|
|
* But, it doesn't use a checksum. You can control these options using the
|
||
|
|
* advanced API: ZSTD_CCtx_setParameter(), ZSTD_CCtx_refCDict(),
|
||
|
|
* and ZSTD_compress2().
|
||
|
|
*/
|
||
|
|
ZSTD_CCtx* const cctx = ZSTD_createCCtx();
|
||
|
|
CHECK(cctx != NULL, "ZSTD_createCCtx() failed!");
|
||
|
|
size_t const cSize = ZSTD_compress_usingCDict(cctx, cBuff, cBuffSize, fBuff, fSize, cdict);
|
||
|
|
CHECK_ZSTD(cSize);
|
||
|
|
|
||
|
|
saveFile_orDie(oname, cBuff, cSize);
|
||
|
|
|
||
|
|
/* success */
|
||
|
|
printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname);
|
||
|
|
|
||
|
|
ZSTD_freeCCtx(cctx); /* never fails */
|
||
|
|
free(fBuff);
|
||
|
|
free(cBuff);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
static char* createOutFilename_orDie(const char* filename)
|
||
|
|
{
|
||
|
|
size_t const inL = strlen(filename);
|
||
|
|
size_t const outL = inL + 5;
|
||
|
|
void* outSpace = malloc_orDie(outL);
|
||
|
|
memset(outSpace, 0, outL);
|
||
|
|
strcat(outSpace, filename);
|
||
|
|
strcat(outSpace, ".zst");
|
||
|
|
return (char*)outSpace;
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(int argc, const char** argv)
|
||
|
|
{
|
||
|
|
const char* const exeName = argv[0];
|
||
|
|
int const cLevel = 3;
|
||
|
|
|
||
|
|
if (argc<3) {
|
||
|
|
fprintf(stderr, "wrong arguments\n");
|
||
|
|
fprintf(stderr, "usage:\n");
|
||
|
|
fprintf(stderr, "%s [FILES] dictionary\n", exeName);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* load dictionary only once */
|
||
|
|
const char* const dictName = argv[argc-1];
|
||
|
|
ZSTD_CDict* const dictPtr = createCDict_orDie(dictName, cLevel);
|
||
|
|
|
||
|
|
int u;
|
||
|
|
for (u=1; u<argc-1; u++) {
|
||
|
|
const char* inFilename = argv[u];
|
||
|
|
char* const outFilename = createOutFilename_orDie(inFilename);
|
||
|
|
compress(inFilename, outFilename, dictPtr);
|
||
|
|
free(outFilename);
|
||
|
|
}
|
||
|
|
|
||
|
|
ZSTD_freeCDict(dictPtr);
|
||
|
|
printf("All %u files compressed. \n", argc-2);
|
||
|
|
return 0;
|
||
|
|
}
|