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Diffstat (limited to 'src/zstd/examples/simple_compression.c')
-rw-r--r-- | src/zstd/examples/simple_compression.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/zstd/examples/simple_compression.c b/src/zstd/examples/simple_compression.c new file mode 100644 index 00000000..9ade424a --- /dev/null +++ b/src/zstd/examples/simple_compression.c @@ -0,0 +1,135 @@ +/* + * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + + + +#include <stdlib.h> // malloc, free, exit +#include <stdio.h> // fprintf, perror, fopen, etc. +#include <string.h> // strlen, strcat, memset, 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(NULL); + exit(3); +} + +static void* loadFile_orDie(const char* fileName, size_t* size) +{ + off_t const fileSize = fsize_orDie(fileName); + size_t const buffSize = (size_t)fileSize; + if ((off_t)buffSize < fileSize) { /* narrowcast overflow */ + fprintf(stderr, "%s : filesize too large \n", fileName); + exit(4); + } + 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(5); + } + fclose(inFile); /* can't fail, read only */ + *size = buffSize; + return buffer; +} + + +static void saveFile_orDie(const char* fileName, const void* buff, size_t buffSize) +{ + FILE* const oFile = fopen_orDie(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(6); + } + if (fclose(oFile)) { + perror(fileName); + exit(7); + } +} + + +static void compress_orDie(const char* fname, const char* oname) +{ + size_t fSize; + void* const fBuff = loadFile_orDie(fname, &fSize); + size_t const cBuffSize = ZSTD_compressBound(fSize); + void* const cBuff = malloc_orDie(cBuffSize); + + size_t const cSize = ZSTD_compress(cBuff, cBuffSize, fBuff, fSize, 1); + if (ZSTD_isError(cSize)) { + fprintf(stderr, "error compressing %s : %s \n", fname, ZSTD_getErrorName(cSize)); + exit(8); + } + + saveFile_orDie(oname, cBuff, cSize); + + /* success */ + printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname); + + free(fBuff); + free(cBuff); +} + + +static char* createOutFilename_orDie(const char* filename) +{ + size_t const inL = strlen(filename); + size_t const outL = inL + 5; + void* const outSpace = malloc_orDie(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!=2) { + printf("wrong arguments\n"); + printf("usage:\n"); + printf("%s FILE\n", exeName); + return 1; + } + + const char* const inFilename = argv[1]; + + char* const outFilename = createOutFilename_orDie(inFilename); + compress_orDie(inFilename, outFilename); + free(outFilename); + return 0; +} |