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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* 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.
*/
/* The objective of this example is to show of to compress multiple successive files
* while preserving memory management.
* All structures and buffers will be created only once,
* and shared across all compression operations */
#include <stdlib.h> // malloc, exit
#include <stdio.h> // fprintf, perror, feof
#include <string.h> // strerror
#include <errno.h> // errno
#define ZSTD_STATIC_LINKING_ONLY // streaming API defined as "experimental" for the time being
#include <zstd.h> // presumes zstd library is installed
static void* malloc_orDie(size_t size)
{
void* const buff = malloc(size);
if (buff) return buff;
/* error */
perror("malloc:");
exit(1);
}
static FILE* fopen_orDie(const char *filename, const char *instruction)
{
FILE* const inFile = fopen(filename, instruction);
if (inFile) return inFile;
/* error */
perror(filename);
exit(3);
}
static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
{
size_t const readSize = fread(buffer, 1, sizeToRead, file);
if (readSize == sizeToRead) return readSize; /* good */
if (feof(file)) return readSize; /* good, reached end of file */
/* error */
perror("fread");
exit(4);
}
static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
{
size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
if (writtenSize == sizeToWrite) return sizeToWrite; /* good */
/* error */
perror("fwrite");
exit(5);
}
static size_t fclose_orDie(FILE* file)
{
if (!fclose(file)) return 0;
/* error */
perror("fclose");
exit(6);
}
typedef struct {
void* buffIn;
void* buffOut;
size_t buffInSize;
size_t buffOutSize;
ZSTD_CStream* cstream;
} resources ;
static resources createResources_orDie()
{
resources ress;
ress.buffInSize = ZSTD_CStreamInSize(); /* can always read one full block */
ress.buffOutSize= ZSTD_CStreamOutSize(); /* can always flush a full block */
ress.buffIn = malloc_orDie(ress.buffInSize);
ress.buffOut= malloc_orDie(ress.buffOutSize);
ress.cstream = ZSTD_createCStream();
if (ress.cstream==NULL) { fprintf(stderr, "ZSTD_createCStream() error \n"); exit(10); }
return ress;
}
static void freeResources(resources ress)
{
ZSTD_freeCStream(ress.cstream);
free(ress.buffIn);
free(ress.buffOut);
}
static void compressFile_orDie(resources ress, const char* fname, const char* outName, int cLevel)
{
FILE* const fin = fopen_orDie(fname, "rb");
FILE* const fout = fopen_orDie(outName, "wb");
size_t const initResult = ZSTD_initCStream(ress.cstream, cLevel);
if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_initCStream() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
size_t read, toRead = ress.buffInSize;
while( (read = fread_orDie(ress.buffIn, toRead, fin)) ) {
ZSTD_inBuffer input = { ress.buffIn, read, 0 };
while (input.pos < input.size) {
ZSTD_outBuffer output = { ress.buffOut, ress.buffOutSize, 0 };
toRead = ZSTD_compressStream(ress.cstream, &output , &input); /* toRead is guaranteed to be <= ZSTD_CStreamInSize() */
if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_compressStream() error : %s \n", ZSTD_getErrorName(toRead)); exit(12); }
if (toRead > ress.buffInSize) toRead = ress.buffInSize; /* Safely handle when `buffInSize` is manually changed to a smaller value */
fwrite_orDie(ress.buffOut, output.pos, fout);
}
}
ZSTD_outBuffer output = { ress.buffOut, ress.buffOutSize, 0 };
size_t const remainingToFlush = ZSTD_endStream(ress.cstream, &output); /* close frame */
if (remainingToFlush) { fprintf(stderr, "not fully flushed"); exit(13); }
fwrite_orDie(ress.buffOut, output.pos, fout);
fclose_orDie(fout);
fclose_orDie(fin);
}
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;
}
resources const ress = createResources_orDie();
void* ofnBuffer = NULL;
size_t ofnbSize = 0;
int argNb;
for (argNb = 1; argNb < argc; argNb++) {
const char* const ifn = argv[argNb];
size_t const ifnSize = strlen(ifn);
size_t const ofnSize = ifnSize + 5;
if (ofnbSize <= ofnSize) {
ofnbSize = ofnSize + 16;
free(ofnBuffer);
ofnBuffer = malloc_orDie(ofnbSize);
}
memset(ofnBuffer, 0, ofnSize);
strcat(ofnBuffer, ifn);
strcat(ofnBuffer, ".zst");
compressFile_orDie(ress, ifn, ofnBuffer, 7);
}
freeResources(ress);
free(ofnBuffer);
printf("compressed %i files \n", argc-1);
return 0;
}
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