diff --git a/examples/.gitignore b/examples/.gitignore index 5c9836d3..9d241dba 100644 --- a/examples/.gitignore +++ b/examples/.gitignore @@ -1,6 +1,7 @@ #build simple_compression simple_decompression +dictionary_compression dictionary_decompression #test artefact diff --git a/examples/Makefile b/examples/Makefile index b20d14a7..5e3f0e17 100644 --- a/examples/Makefile +++ b/examples/Makefile @@ -30,7 +30,8 @@ LDFLAGS+= -lzstd default: all -all: simple_compression simple_decompression dictionary_decompression +all: simple_compression simple_decompression \ + dictionary_compression dictionary_decompression simple_compression : simple_compression.c $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ @@ -38,12 +39,16 @@ simple_compression : simple_compression.c simple_decompression : simple_decompression.c $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ +dictionary_compression : dictionary_compression.c + $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ + dictionary_decompression : dictionary_decompression.c $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ clean: @rm -f core *.o tmp* result* *.zst \ - simple_compression simple_decompression dictionary_decompression + simple_compression simple_decompression \ + dictionary_compression dictionary_decompression @echo Cleaning completed test: all diff --git a/examples/dictionary_compression.c b/examples/dictionary_compression.c new file mode 100644 index 00000000..fc176a3d --- /dev/null +++ b/examples/dictionary_compression.c @@ -0,0 +1,163 @@ +/* + 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 // malloc, exit +#include // printf +#include // strerror +#include // errno +#include // stat +#include // 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 */ + perror(filename); + exit(1); +} + +static FILE* fopen_X(const char *filename, const char *instruction) +{ + FILE* const inFile = fopen(filename, instruction); + if (inFile) return inFile; + /* error */ + perror(filename); + exit(2); +} + +static void* malloc_X(size_t size) +{ + void* const buff = malloc(size); + if (buff) return buff; + /* error */ + perror(NULL); + 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) { + fprintf(stderr, "fread: %s : %s \n", fileName, strerror(errno)); + exit(4); + } + fclose(inFile); + *size = buffSize; + return buffer; +} + +static void saveFile_X(const char* fileName, const void* buff, size_t buffSize) +{ + FILE* const oFile = fopen_X(fileName, "wb"); + size_t const wSize = fwrite(buff, 1, buffSize, oFile); + if (wSize != (size_t)buffSize) { + fprintf(stderr, "fwrite: %s : %s \n", fileName, strerror(errno)); + exit(5); + } + if (fclose(oFile)) { + perror(fileName); + exit(6); + } +} + +/* createDict() : + `dictFileName` is supposed to have been created using `zstd --train` */ +static const ZSTD_CDict* createDict(const char* dictFileName) +{ + size_t dictSize; + printf("loading dictionary %s \n", dictFileName); + void* const dictBuffer = loadFile_X(dictFileName, &dictSize); + const ZSTD_CDict* const ddict = ZSTD_createCDict(dictBuffer, dictSize, 3); + free(dictBuffer); + return ddict; +} + + +static void compress(const char* fname, const char* oname, const ZSTD_CDict* cdict) +{ + size_t fSize; + void* const fBuff = loadFile_X(fname, &fSize); + size_t const cBuffSize = ZSTD_compressBound(fSize); + void* const cBuff = malloc_X(cBuffSize); + + ZSTD_CCtx* const cctx = ZSTD_createCCtx(); + size_t const cSize = ZSTD_compress_usingCDict(cctx, cBuff, cBuffSize, fBuff, fSize, cdict); + if (ZSTD_isError(cSize)) { + fprintf(stderr, "error compressing %s : %s \n", fname, ZSTD_getErrorName(cSize)); + exit(7); + } + + saveFile_X(oname, cBuff, cSize); + + /* success */ + printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname); + + ZSTD_freeCCtx(cctx); + free(fBuff); + free(cBuff); +} + + +static char* createOutFilename(const char* filename) +{ + size_t const inL = strlen(filename); + size_t const outL = inL + 5; + void* outSpace = malloc_X(outL); + memset(outSpace, 0, outL); + strcat(outSpace, filename); + strcat(outSpace, ".zst"); + return (char*)outSpace; +} + +int main(int argc, const char** argv) +{ + const char* const exeName = argv[0]; + + if (argc<3) { + fprintf(stderr, "wrong arguments\n"); + fprintf(stderr, "usage:\n"); + fprintf(stderr, "%s [FILES] dictionary\n", exeName); + return 1; + } + + /* load dictionary only once */ + const char* const dictName = argv[argc-1]; + const ZSTD_CDict* const dictPtr = createDict(dictName); + + int u; + for (u=1; u