ceph/src/zstd/examples/simple_compression.c

   1 /*
   2  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under both the BSD-style license (found in the
   6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
   7  * in the COPYING file in the root directory of this source tree).
   8  * You may select, at your option, one of the above-listed licenses.
   9  */
  10
  11
  12
  13 #include <stdlib.h>    // malloc, free, exit
  14 #include <stdio.h>     // fprintf, perror, fopen, etc.
  15 #include <string.h>    // strlen, strcat, memset, strerror
  16 #include <errno.h>     // errno
  17 #include <sys/stat.h>  // stat
  18 #include <zstd.h>      // presumes zstd library is installed
  19
  20
  21 static off_t fsize_orDie(const char *filename)
  22 {
  23     struct stat st;
  24     if (stat(filename, &st) == 0) return st.st_size;
  25     /* error */
  26     perror(filename);
  27     exit(1);
  28 }
  29
  30 static FILE* fopen_orDie(const char *filename, const char *instruction)
  31 {
  32     FILE* const inFile = fopen(filename, instruction);
  33     if (inFile) return inFile;
  34     /* error */
  35     perror(filename);
  36     exit(2);
  37 }
  38
  39 static void* malloc_orDie(size_t size)
  40 {
  41     void* const buff = malloc(size);
  42     if (buff) return buff;
  43     /* error */
  44     perror(NULL);
  45     exit(3);
  46 }
  47
  48 static void* loadFile_orDie(const char* fileName, size_t* size)
  49 {
  50     off_t const fileSize = fsize_orDie(fileName);
  51     size_t const buffSize = (size_t)fileSize;
  52     if ((off_t)buffSize < fileSize) {   /* narrowcast overflow */
  53         fprintf(stderr, "%s : filesize too large \n", fileName);
  54         exit(4);
  55     }
  56     FILE* const inFile = fopen_orDie(fileName, "rb");
  57     void* const buffer = malloc_orDie(buffSize);
  58     size_t const readSize = fread(buffer, 1, buffSize, inFile);
  59     if (readSize != (size_t)buffSize) {
  60         fprintf(stderr, "fread: %s : %s \n", fileName, strerror(errno));
  61         exit(5);
  62     }
  63     fclose(inFile);  /* can't fail, read only */
  64     *size = buffSize;
  65     return buffer;
  66 }
  67
  68
  69 static void saveFile_orDie(const char* fileName, const void* buff, size_t buffSize)
  70 {
  71     FILE* const oFile = fopen_orDie(fileName, "wb");
  72     size_t const wSize = fwrite(buff, 1, buffSize, oFile);
  73     if (wSize != (size_t)buffSize) {
  74         fprintf(stderr, "fwrite: %s : %s \n", fileName, strerror(errno));
  75         exit(6);
  76     }
  77     if (fclose(oFile)) {
  78         perror(fileName);
  79         exit(7);
  80     }
  81 }
  82
  83
  84 static void compress_orDie(const char* fname, const char* oname)
  85 {
  86     size_t fSize;
  87     void* const fBuff = loadFile_orDie(fname, &fSize);
  88     size_t const cBuffSize = ZSTD_compressBound(fSize);
  89     void* const cBuff = malloc_orDie(cBuffSize);
  90
  91     size_t const cSize = ZSTD_compress(cBuff, cBuffSize, fBuff, fSize, 1);
  92     if (ZSTD_isError(cSize)) {
  93         fprintf(stderr, "error compressing %s : %s \n", fname, ZSTD_getErrorName(cSize));
  94         exit(8);
  95     }
  96
  97     saveFile_orDie(oname, cBuff, cSize);
  98
  99     /* success */
 100     printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname);
 101
 102     free(fBuff);
 103     free(cBuff);
 104 }
 105
 106
 107 static char* createOutFilename_orDie(const char* filename)
 108 {
 109     size_t const inL = strlen(filename);
 110     size_t const outL = inL + 5;
 111     void* const outSpace = malloc_orDie(outL);
 112     memset(outSpace, 0, outL);
 113     strcat(outSpace, filename);
 114     strcat(outSpace, ".zst");
 115     return (char*)outSpace;
 116 }
 117
 118 int main(int argc, const char** argv)
 119 {
 120     const char* const exeName = argv[0];
 121
 122     if (argc!=2) {
 123         printf("wrong arguments\n");
 124         printf("usage:\n");
 125         printf("%s FILE\n", exeName);
 126         return 1;
 127     }
 128
 129     const char* const inFilename = argv[1];
 130
 131     char* const outFilename = createOutFilename_orDie(inFilename);
 132     compress_orDie(inFilename, outFilename);
 133     free(outFilename);
 134     return 0;
 135 }