added streaming_compression.c example

This commit is contained in:
Yann Collet 2016-08-12 18:42:25 +02:00
parent d7883a2c0e
commit 553b213ada
3 changed files with 155 additions and 5 deletions

1
examples/.gitignore vendored
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@ -3,6 +3,7 @@ simple_compression
simple_decompression
dictionary_compression
dictionary_decompression
streaming_compression
#test artefact
tmp*

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@ -31,7 +31,8 @@ LDFLAGS+= -lzstd
default: all
all: simple_compression simple_decompression \
dictionary_compression dictionary_decompression
dictionary_compression dictionary_decompression \
streaming_compression
simple_compression : simple_compression.c
$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
@ -45,19 +46,24 @@ dictionary_compression : dictionary_compression.c
dictionary_decompression : dictionary_decompression.c
$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
streaming_compression : streaming_compression.c
$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
clean:
@rm -f core *.o tmp* result* *.zst \
simple_compression simple_decompression \
dictionary_compression dictionary_decompression
dictionary_compression dictionary_decompression \
streaming_compression
@echo Cleaning completed
test: all
cp README.md tmp
@echo starting simple compression
./simple_compression tmp
@echo starting simple_decompression
./simple_decompression tmp.zst
@echo dictionary compression
@echo starting streaming compression
./streaming_compression tmp
@echo starting dictionary compression
./dictionary_compression tmp README.md
@echo dictionary decompression
./dictionary_decompression tmp.zst README.md
@echo tests completed

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@ -0,0 +1,143 @@
/*
Streaming 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> // fprintf, perror
#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(NULL);
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);
}
static void compressFile_orDie(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 buffInSize = ZSTD_CStreamInSize();;
void* const buffIn = malloc_orDie(buffInSize);
size_t const buffOutSize = ZSTD_CStreamOutSize();;
void* const buffOut = malloc_orDie(buffOutSize);
size_t read, toRead = buffInSize;
ZSTD_CStream* const cstream = ZSTD_createCStream();
if (cstream==NULL) { fprintf(stderr, "ZSTD_createCStream() error \n"); exit(10); }
size_t const initResult = ZSTD_initCStream(cstream, cLevel);
if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_initCStream() error \n"); exit(11); }
while( (read = fread_orDie(buffIn, toRead, fin)) ) {
ZSTD_rCursor cursin = { buffIn, read };
while (cursin.size) {
ZSTD_wCursor cursout = { buffOut, buffOutSize, 0 };
toRead = ZSTD_compressStream(cstream, &cursout , &cursin);
fwrite_orDie(buffOut, cursout.nbBytesWritten, fout);
}
}
ZSTD_wCursor cursout = { buffOut, buffOutSize, 0 };
size_t const remainingToFlush = ZSTD_endStream(cstream, &cursout);
if (remainingToFlush) { fprintf(stderr, "not fully flushed"); exit(12); }
fwrite_orDie(buffOut, cursout.nbBytesWritten, fout);
fclose_orDie(fout);
fclose_orDie(fin);
free(buffIn);
free(buffOut);
}
static const 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 (const char*)outSpace;
}
int main(int argc, const char** argv)
{
const char* const exeName = argv[0];
const char* const inFilename = argv[1];
if (argc!=2) {
printf("wrong arguments\n");
printf("usage:\n");
printf("%s FILE\n", exeName);
return 1;
}
const char* const outFilename = createOutFilename_orDie(inFilename);
compressFile_orDie(inFilename, outFilename, 1);
return 0;
}