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added simple examples

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Yann Collet 2016-07-09 18:25:10 +02:00
parent 3b6ae77e15
commit 0809a8863d
4 changed files with 277 additions and 13 deletions
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9
examples/README.md
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@ -1,7 +1,14 @@
Zstandard library : usage examples
==================================
- [Simple compression](simple_compression.c)
Compress a single file.
Introduces usage of : `ZSTD_compress()`
- [Simple decompression](simple_decompression.c)
Decompress a single file compressed by zstd.
Introduces usage of : `ZSTD_decompress()`
- [Dictionary decompression](dictionary_decompression.c)
Decompress multiple files using the same dictionary.
Compatible with Legacy modes.
Introduces usage of : `ZSTD_createDDict()` and `ZSTD_decompress_usingDDict()`

49
examples/dictionary_decompression.c
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@ -1,12 +1,37 @@
#include <stdlib.h> // exit
/*
Dictionary decompression
Educational program using zstd library
Copyright (C) Yann Collet 2016
GPL v2 License
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
You can contact the author at :
- zstd homepage : http://www.zstd.net/
*/
#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>
#include <zstd.h> // presumes zstd library is installed
static off_t fsizeX(const char *filename)
static off_t fsize_X(const char *filename)
{
struct stat st;
if (stat(filename, &st) == 0) return st.st_size;
@ -15,7 +40,7 @@ static off_t fsizeX(const char *filename)
exit(1);
}
static FILE* fopenX(const char *filename, const char *instruction)
static FILE* fopen_X(const char *filename, const char *instruction)
{
FILE* const inFile = fopen(filename, instruction);
if (inFile) return inFile;
@ -24,7 +49,7 @@ static FILE* fopenX(const char *filename, const char *instruction)
exit(2);
}
static void* mallocX(size_t size)
static void* malloc_X(size_t size)
{
void* const buff = malloc(size);
if (buff) return buff;
@ -33,11 +58,11 @@ static void* mallocX(size_t size)
exit(3);
}
static void* loadFileX(const char* fileName, size_t* size)
static void* loadFile_X(const char* fileName, size_t* size)
{
off_t const buffSize = fsizeX(fileName);
FILE* const inFile = fopenX(fileName, "rb");
void* const buffer = mallocX(buffSize);
off_t const buffSize = fsize_X(fileName);
FILE* const inFile = fopen_X(fileName, "rb");
void* const buffer = malloc_X(buffSize);
size_t const readSize = fread(buffer, 1, buffSize, inFile);
if (readSize != (size_t)buffSize) {
printf("fread: %s : %s \n", fileName, strerror(errno));
@ -52,7 +77,7 @@ static void* loadFileX(const char* fileName, size_t* size)
static const ZSTD_DDict* createDict(const char* dictFileName)
{
size_t dictSize;
void* const dictBuffer = loadFileX(dictFileName, &dictSize);
void* const dictBuffer = loadFile_X(dictFileName, &dictSize);
const ZSTD_DDict* const ddict = ZSTD_createDDict(dictBuffer, dictSize);
free(dictBuffer);
return ddict;
@ -65,13 +90,13 @@ unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
static void decompress(const char* fname, const ZSTD_DDict* ddict)
{
size_t cSize;
void* const cBuff = loadFileX(fname, &cSize);
void* const cBuff = loadFile_X(fname, &cSize);
unsigned long long const rSize = ZSTD_getDecompressedSize(cBuff, cSize);
if (rSize==0) {
printf("%s : original size unknown \n", fname);
exit(5);
}
void* const rBuff = mallocX(rSize);
void* const rBuff = malloc_X(rSize);
ZSTD_DCtx* const dctx = ZSTD_createDCtx();
size_t const dSize = ZSTD_decompress_usingDDict(dctx, rBuff, rSize, cBuff, cSize, ddict);

112
examples/simple_compression.c Normal file
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@ -0,0 +1,112 @@
/*
Simple compression
Educational program using zstd library
Copyright (C) Yann Collet 2016
GPL v2 License
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
You can contact the author at :
- zstd homepage : http://www.zstd.net/
*/
#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_X(const char *filename)
{
struct stat st;
if (stat(filename, &st) == 0) return st.st_size;
/* error */
printf("stat: %s : %s \n", filename, strerror(errno));
exit(1);
}
static FILE* fopen_X(const char *filename, const char *instruction)
{
FILE* const inFile = fopen(filename, instruction);
if (inFile) return inFile;
/* error */
printf("fopen: %s : %s \n", filename, strerror(errno));
exit(2);
}
static void* malloc_X(size_t size)
{
void* const buff = malloc(size);
if (buff) return buff;
/* error */
printf("malloc: %s \n", strerror(errno));
exit(3);
}
static void* loadFile_X(const char* fileName, size_t* size)
{
off_t const buffSize = fsize_X(fileName);
FILE* const inFile = fopen_X(fileName, "rb");
void* const buffer = malloc_X(buffSize);
size_t const readSize = fread(buffer, 1, buffSize, inFile);
if (readSize != (size_t)buffSize) {
printf("fread: %s : %s \n", fileName, strerror(errno));
exit(4);
}
fclose(inFile);
*size = buffSize;
return buffer;
}
static void compress(const char* fname)
{
size_t fSize;
void* const fBuff = loadFile_X(fname, &fSize);
size_t const cBuffSize = ZSTD_compressBound(fSize);
void* const cBuff = malloc_X(cBuffSize);
size_t const cSize = ZSTD_compress(cBuff, cBuffSize, fBuff, fSize, 1);
if (ZSTD_isError(cSize)) {
printf("error compressing %s : %s \n", fname, ZSTD_getErrorName(cSize));
exit(7);
}
/* success */
printf("%25s : %6u -> %7u \n", fname, (unsigned)fSize, (unsigned)cSize);
free(fBuff);
free(cBuff);
}
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\n", exeName);
return 1;
}
compress(argv[1]);
printf("%s compressed. \n", argv[1]);
}

120
examples/simple_decompression.c Normal file
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@ -0,0 +1,120 @@
/*
Simple decompression
Educational program using zstd library
Copyright (C) Yann Collet 2016
GPL v2 License
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
You can contact the author at :
- zstd homepage : http://www.zstd.net/
*/
#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_X(const char *filename)
{
struct stat st;
if (stat(filename, &st) == 0) return st.st_size;
/* error */
printf("stat: %s : %s \n", filename, strerror(errno));
exit(1);
}
static FILE* fopen_X(const char *filename, const char *instruction)
{
FILE* const inFile = fopen(filename, instruction);
if (inFile) return inFile;
/* error */
printf("fopen: %s : %s \n", filename, strerror(errno));
exit(2);
}
static void* malloc_X(size_t size)
{
void* const buff = malloc(size);
if (buff) return buff;
/* error */
printf("malloc: %s \n", strerror(errno));
exit(3);
}
static void* loadFile_X(const char* fileName, size_t* size)
{
off_t const buffSize = fsize_X(fileName);
FILE* const inFile = fopen_X(fileName, "rb");
void* const buffer = malloc_X(buffSize);
size_t const readSize = fread(buffer, 1, buffSize, inFile);
if (readSize != (size_t)buffSize) {
printf("fread: %s : %s \n", fileName, strerror(errno));
exit(4);
}
fclose(inFile);
*size = buffSize;
return buffer;
}
/* prototype declared here, as it is currently part of experimental section */
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
static void decompress(const char* fname)
{
size_t cSize;
void* const cBuff = loadFile_X(fname, &cSize);
unsigned long long const rSize = ZSTD_getDecompressedSize(cBuff, cSize);
if (rSize==0) {
printf("%s : original size unknown \n", fname);
exit(5);
}
void* const rBuff = malloc_X(rSize);
size_t const dSize = ZSTD_decompress(rBuff, rSize, cBuff, cSize);
if (dSize != rSize) {
printf("error decoding %s : %s \n", fname, ZSTD_getErrorName(dSize));
exit(7);
}
/* success */
printf("%25s : %6u -> %7u \n", fname, (unsigned)cSize, (unsigned)rSize);
free(rBuff);
free(cBuff);
}
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\n", exeName);
return 1;
}
decompress(argv[1]);
printf("%s decoded. \n", argv[1]);
}