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

117 lines
3.7 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.
*/
#include <stdio.h> // printf
#include <stdlib.h> // free
#include <string.h> // memcpy, strlen
#include <zstd.h> // presumes zstd library is installed
#include "common.h" // Helper functions, CHECK(), and CHECK_ZSTD()
typedef struct {
void* fBuffer;
void* cBuffer;
size_t fBufferSize;
size_t cBufferSize;
ZSTD_CCtx* cctx;
} resources;
/*
* allocate memory for buffers big enough to compress all files
* as well as memory for output file name (ofn)
*/
static resources createResources_orDie(int argc, const char** argv, char **ofn, size_t* ofnBufferLen)
{
size_t maxFilenameLength=0;
size_t maxFileSize = 0;
int argNb;
for (argNb = 1; argNb < argc; argNb++) {
const char* const filename = argv[argNb];
size_t const filenameLength = strlen(filename);
size_t const fileSize = fsize_orDie(filename);
if (filenameLength > maxFilenameLength) maxFilenameLength = filenameLength;
if (fileSize > maxFileSize) maxFileSize = fileSize;
}
resources ress;
ress.fBufferSize = maxFileSize;
ress.cBufferSize = ZSTD_compressBound(maxFileSize);
*ofnBufferLen = maxFilenameLength + 5;
*ofn = (char*)malloc_orDie(*ofnBufferLen);
ress.fBuffer = malloc_orDie(ress.fBufferSize);
ress.cBuffer = malloc_orDie(ress.cBufferSize);
ress.cctx = ZSTD_createCCtx();
CHECK(ress.cctx != NULL, "ZSTD_createCCtx() failed!");
return ress;
}
static void freeResources(resources ress, char *outFilename)
{
free(ress.fBuffer);
free(ress.cBuffer);
ZSTD_freeCCtx(ress.cctx); /* never fails */
free(outFilename);
}
/* compress with pre-allocated context (ZSTD_CCtx) and input/output buffers*/
static void compressFile_orDie(resources ress, const char* fname, const char* oname)
{
size_t fSize = loadFile_orDie(fname, ress.fBuffer, ress.fBufferSize);
/* Compress using the context.
* If you need more control over parameters, use the advanced API:
* ZSTD_CCtx_setParameter(), and ZSTD_compress2().
*/
size_t const cSize = ZSTD_compressCCtx(ress.cctx, ress.cBuffer, ress.cBufferSize, ress.fBuffer, fSize, 1);
CHECK_ZSTD(cSize);
saveFile_orDie(oname, ress.cBuffer, cSize);
/* success */
printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname);
}
int main(int argc, const char** argv)
{
const char* const exeName = argv[0];
if (argc<2) {
printf("wrong arguments\n");
printf("usage:\n");
printf("%s FILE(s)\n", exeName);
return 1;
}
/* memory allocation for outFilename and resources */
char* outFilename;
size_t outFilenameBufferLen;
resources const ress = createResources_orDie(argc, argv, &outFilename, &outFilenameBufferLen);
/* compress files with shared context, input and output buffers */
int argNb;
for (argNb = 1; argNb < argc; argNb++) {
const char* const inFilename = argv[argNb];
size_t const inFilenameLen = strlen(inFilename);
CHECK(inFilenameLen + 5 <= outFilenameBufferLen, "File name too long!");
memcpy(outFilename, inFilename, inFilenameLen);
memcpy(outFilename+inFilenameLen, ".zst", 5);
compressFile_orDie(ress, inFilename, outFilename);
}
/* free memory */
freeResources(ress,outFilename);
printf("compressed %i files \n", argc-1);
return 0;
}