mirrors/zstd
0
0
Fork 0
mirror of https://github.com/facebook/zstd.git synced 2024-11-28 15:26:54 +08:00
Code Issues Packages Projects Releases Wiki Activity

updated decompression streaming example

Browse Source
This commit is contained in:
Yann Collet 2016-09-08 19:29:04 +02:00
parent 5c6d244973
commit 01c199226a
3 changed files with 24 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
examples/Makefile
View File

@ -55,8 +55,8 @@ streaming_decompression : streaming_decompression.c
clean:
@rm -f core *.o tmp* result* *.zst \
simple_compression simple_decompression \
dictionary_compression dictionary_decompression \
streaming_compression streaming_decompression
dictionary_compression dictionary_decompression \
streaming_compression streaming_decompression
@echo Cleaning completed
test: all
@ -64,7 +64,7 @@ test: all
@echo starting simple compression
./simple_compression tmp
./simple_decompression tmp.zst
./streaming_decompression tmp.zst
./streaming_decompression tmp.zst > /dev/null
@echo starting streaming compression
./streaming_compression tmp
./streaming_decompression tmp.zst

26
examples/streaming_decompression.c
View File

@ -42,6 +42,16 @@ static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
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;
@ -54,28 +64,30 @@ static size_t fclose_orDie(FILE* file)
static void decompressFile_orDie(const char* fname)
{
FILE* const fin = fopen_orDie(fname, "rb");
size_t const buffInSize = ZSTD_DStreamInSize();;
size_t const buffInSize = ZSTD_DStreamInSize();
void* const buffIn = malloc_orDie(buffInSize);
size_t const buffOutSize = ZSTD_DStreamOutSize();;
size_t const buffOutSize = ZSTD_DStreamOutSize(); /* Guarantee to successfully flush at least one complete compressed block in all circumstances. */
void* const buffOut = malloc_orDie(buffOutSize);
size_t read, toRead = buffInSize;
FILE* const fout = stdout;
ZSTD_DStream* const dstream = ZSTD_createDStream();
if (dstream==NULL) { fprintf(stderr, "ZSTD_createDStream() error \n"); exit(10); }
size_t const initResult = ZSTD_initDStream(dstream);
if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_initDStream() error \n"); exit(11); }
size_t toRead = initResult;
while( (read = fread_orDie(buffIn, toRead, fin)) ) {
size_t read;
while ( (read = fread_orDie(buffIn, toRead, fin)) ) {
ZSTD_inBuffer input = { buffIn, read, 0 };
while (input.pos < input.size) {
ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
toRead = ZSTD_decompressStream(dstream, &output , &input);
/* note : data is just "sinked" into buffOut
a more complete example would write it to disk or stdout */
toRead = ZSTD_decompressStream(dstream, &output , &input); /* toRead : size of next compressed block */
fwrite_orDie(buffOut, output.pos, fout);
}
}
fclose_orDie(fin);
fclose_orDie(fout);
free(buffIn);
free(buffOut);
}

4
lib/zstd.h
View File

@ -229,7 +229,7 @@ ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
ZSTDLIB_API size_t ZSTD_CStreamInSize(void); /**< recommended size for input buffer */
ZSTDLIB_API size_t ZSTD_CStreamOutSize(void); /**< recommended size for output buffer */
ZSTDLIB_API size_t ZSTD_CStreamOutSize(void); /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */
ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
@ -268,7 +268,7 @@ ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
ZSTDLIB_API size_t ZSTD_DStreamInSize(void); /*!< recommended size for input buffer */
ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output buffer */
ZSTDLIB_API size_t ZSTD_DStreamOutSize(void); /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);
ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);