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/**
* Copyright 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the license found in the
* LICENSE-examples file in the root directory of this source tree.
*/
#include <stdlib.h> // malloc, exit
#include <stdio.h> // printf
#include <string.h> // strerror
#include <errno.h> // errno
#include <sys/stat.h> // stat
#include <zstd.h> // presumes zstd library is installed
static off_t fsize_orDie(const char *filename)
{
struct stat st;
if (stat(filename, &st) == 0) return st.st_size;
/* error */
perror(filename);
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(2);
}
static void* malloc_orDie(size_t size)
{
void* const buff = malloc(size);
if (buff) return buff;
/* error */
perror("malloc");
exit(3);
}
static void* loadFile_orDie(const char* fileName, size_t* size)
{
off_t const buffSize = fsize_orDie(fileName);
FILE* const inFile = fopen_orDie(fileName, "rb");
void* const buffer = malloc_orDie(buffSize);
size_t const readSize = fread(buffer, 1, buffSize, inFile);
if (readSize != (size_t)buffSize) {
fprintf(stderr, "fread: %s : %s \n", fileName, strerror(errno));
exit(4);
}
fclose(inFile);
*size = buffSize;
return buffer;
}
/* createDict() :
`dictFileName` is supposed to have been created using `zstd --train` */
static ZSTD_DDict* createDict_orDie(const char* dictFileName)
{
size_t dictSize;
printf("loading dictionary %s \n", dictFileName);
void* const dictBuffer = loadFile_orDie(dictFileName, &dictSize);
ZSTD_DDict* const ddict = ZSTD_createDDict(dictBuffer, dictSize);
if (ddict==NULL) { fprintf(stderr, "ZSTD_createDDict error \n"); exit(5); }
free(dictBuffer);
return ddict;
}
static void decompress(const char* fname, const ZSTD_DDict* ddict)
{
size_t cSize;
void* const cBuff = loadFile_orDie(fname, &cSize);
unsigned long long const rSize = ZSTD_getDecompressedSize(cBuff, cSize);
if (rSize==0) {
fprintf(stderr, "%s : original size unknown \n", fname);
exit(6);
}
void* const rBuff = malloc_orDie((size_t)rSize);
ZSTD_DCtx* const dctx = ZSTD_createDCtx();
if (dctx==NULL) { fprintf(stderr, "ZSTD_createDCtx() error \n"); exit(10); }
size_t const dSize = ZSTD_decompress_usingDDict(dctx, rBuff, rSize, cBuff, cSize, ddict);
if (dSize != rSize) {
fprintf(stderr, "error decoding %s : %s \n", fname, ZSTD_getErrorName(dSize));
exit(7);
}
/* success */
printf("%25s : %6u -> %7u \n", fname, (unsigned)cSize, (unsigned)rSize);
ZSTD_freeDCtx(dctx);
free(rBuff);
free(cBuff);
}
int main(int argc, const char** argv)
{
const char* const exeName = argv[0];
if (argc<3) {
printf("wrong arguments\n");
printf("usage:\n");
printf("%s [FILES] dictionary\n", exeName);
return 1;
}
/* load dictionary only once */
const char* const dictName = argv[argc-1];
ZSTD_DDict* const dictPtr = createDict_orDie(dictName);
int u;
for (u=1; u<argc-1; u++) decompress(argv[u], dictPtr);
ZSTD_freeDDict(dictPtr);
printf("All %u files correctly decoded (in memory) \n", argc-2);
return 0;
}
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