ceph/src/zstd/examples/streaming_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 #include <stdlib.h>    // malloc, free, exit
  13 #include <stdio.h>     // fprintf, perror, feof, fopen, etc.
  14 #include <string.h>    // strlen, memset, strcat
  15 #include <zstd.h>      // presumes zstd library is installed
  16
  17
  18 static void* malloc_orDie(size_t size)
  19 {
  20     void* const buff = malloc(size);
  21     if (buff) return buff;
  22     /* error */
  23     perror("malloc:");
  24     exit(1);
  25 }
  26
  27 static FILE* fopen_orDie(const char *filename, const char *instruction)
  28 {
  29     FILE* const inFile = fopen(filename, instruction);
  30     if (inFile) return inFile;
  31     /* error */
  32     perror(filename);
  33     exit(3);
  34 }
  35
  36 static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
  37 {
  38     size_t const readSize = fread(buffer, 1, sizeToRead, file);
  39     if (readSize == sizeToRead) return readSize;   /* good */
  40     if (feof(file)) return readSize;   /* good, reached end of file */
  41     /* error */
  42     perror("fread");
  43     exit(4);
  44 }
  45
  46 static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
  47 {
  48     size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
  49     if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
  50     /* error */
  51     perror("fwrite");
  52     exit(5);
  53 }
  54
  55 static size_t fclose_orDie(FILE* file)
  56 {
  57     if (!fclose(file)) return 0;
  58     /* error */
  59     perror("fclose");
  60     exit(6);
  61 }
  62
  63
  64 static void compressFile_orDie(const char* fname, const char* outName, int cLevel)
  65 {
  66     FILE* const fin  = fopen_orDie(fname, "rb");
  67     FILE* const fout = fopen_orDie(outName, "wb");
  68     size_t const buffInSize = ZSTD_CStreamInSize();    /* can always read one full block */
  69     void*  const buffIn  = malloc_orDie(buffInSize);
  70     size_t const buffOutSize = ZSTD_CStreamOutSize();  /* can always flush a full block */
  71     void*  const buffOut = malloc_orDie(buffOutSize);
  72
  73     ZSTD_CStream* const cstream = ZSTD_createCStream();
  74     if (cstream==NULL) { fprintf(stderr, "ZSTD_createCStream() error \n"); exit(10); }
  75     size_t const initResult = ZSTD_initCStream(cstream, cLevel);
  76     if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_initCStream() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
  77
  78     size_t read, toRead = buffInSize;
  79     while( (read = fread_orDie(buffIn, toRead, fin)) ) {
  80         ZSTD_inBuffer input = { buffIn, read, 0 };
  81         while (input.pos < input.size) {
  82             ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
  83             toRead = ZSTD_compressStream(cstream, &output , &input);   /* toRead is guaranteed to be <= ZSTD_CStreamInSize() */
  84             if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_compressStream() error : %s \n", ZSTD_getErrorName(toRead)); exit(12); }
  85             if (toRead > buffInSize) toRead = buffInSize;   /* Safely handle case when `buffInSize` is manually changed to a value < ZSTD_CStreamInSize()*/
  86             fwrite_orDie(buffOut, output.pos, fout);
  87         }
  88     }
  89
  90     ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
  91     size_t const remainingToFlush = ZSTD_endStream(cstream, &output);   /* close frame */
  92     if (remainingToFlush) { fprintf(stderr, "not fully flushed"); exit(13); }
  93     fwrite_orDie(buffOut, output.pos, fout);
  94
  95     ZSTD_freeCStream(cstream);
  96     fclose_orDie(fout);
  97     fclose_orDie(fin);
  98     free(buffIn);
  99     free(buffOut);
 100 }
 101
 102
 103 static const char* createOutFilename_orDie(const char* filename)
 104 {
 105     size_t const inL = strlen(filename);
 106     size_t const outL = inL + 5;
 107     void* outSpace = malloc_orDie(outL);
 108     memset(outSpace, 0, outL);
 109     strcat(outSpace, filename);
 110     strcat(outSpace, ".zst");
 111     return (const char*)outSpace;
 112 }
 113
 114 int main(int argc, const char** argv)
 115 {
 116     const char* const exeName = argv[0];
 117
 118     if (argc!=2) {
 119         printf("wrong arguments\n");
 120         printf("usage:\n");
 121         printf("%s FILE\n", exeName);
 122         return 1;
 123     }
 124
 125     const char* const inFilename = argv[1];
 126
 127     const char* const outFilename = createOutFilename_orDie(inFilename);
 128     compressFile_orDie(inFilename, outFilename, 1);
 129
 130     return 0;
 131 }