ceph/src/zstd/examples/multiple_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 #include <stdio.h>     // printf
  12 #include <stdlib.h>    // free
  13 #include <string.h>    // memcpy, strlen
  14 #include <zstd.h>      // presumes zstd library is installed
  15 #include "common.h"    // Helper functions, CHECK(), and CHECK_ZSTD()
  16
  17 typedef struct {
  18     void* fBuffer;
  19     void* cBuffer;
  20     size_t fBufferSize;
  21     size_t cBufferSize;
  22     ZSTD_CCtx* cctx;
  23 } resources;
  24
  25 /*
  26  * allocate memory for buffers big enough to compress all files
  27  * as well as memory for output file name (ofn)
  28  */
  29 static resources createResources_orDie(int argc, const char** argv, char **ofn, size_t* ofnBufferLen)
  30 {
  31     size_t maxFilenameLength=0;
  32     size_t maxFileSize = 0;
  33
  34     int argNb;
  35     for (argNb = 1; argNb < argc; argNb++) {
  36       const char* const filename = argv[argNb];
  37       size_t const filenameLength = strlen(filename);
  38       size_t const fileSize = fsize_orDie(filename);
  39
  40       if (filenameLength > maxFilenameLength) maxFilenameLength = filenameLength;
  41       if (fileSize > maxFileSize) maxFileSize = fileSize;
  42     }
  43
  44     resources ress;
  45     ress.fBufferSize = maxFileSize;
  46     ress.cBufferSize = ZSTD_compressBound(maxFileSize);
  47
  48     *ofnBufferLen = maxFilenameLength + 5;
  49     *ofn = (char*)malloc_orDie(*ofnBufferLen);
  50     ress.fBuffer = malloc_orDie(ress.fBufferSize);
  51     ress.cBuffer = malloc_orDie(ress.cBufferSize);
  52     ress.cctx = ZSTD_createCCtx();
  53     CHECK(ress.cctx != NULL, "ZSTD_createCCtx() failed!");
  54     return ress;
  55 }
  56
  57 static void freeResources(resources ress, char *outFilename)
  58 {
  59     free(ress.fBuffer);
  60     free(ress.cBuffer);
  61     ZSTD_freeCCtx(ress.cctx);   /* never fails */
  62     free(outFilename);
  63 }
  64
  65 /* compress with pre-allocated context (ZSTD_CCtx) and input/output buffers*/
  66 static void compressFile_orDie(resources ress, const char* fname, const char* oname)
  67 {
  68     size_t fSize = loadFile_orDie(fname, ress.fBuffer, ress.fBufferSize);
  69
  70     /* Compress using the context.
  71      * If you need more control over parameters, use the advanced API:
  72      * ZSTD_CCtx_setParameter(), and ZSTD_compress2().
  73      */
  74     size_t const cSize = ZSTD_compressCCtx(ress.cctx, ress.cBuffer, ress.cBufferSize, ress.fBuffer, fSize, 1);
  75     CHECK_ZSTD(cSize);
  76
  77     saveFile_orDie(oname, ress.cBuffer, cSize);
  78
  79     /* success */
  80     printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname);
  81 }
  82
  83 int main(int argc, const char** argv)
  84 {
  85     const char* const exeName = argv[0];
  86
  87     if (argc<2) {
  88         printf("wrong arguments\n");
  89         printf("usage:\n");
  90         printf("%s FILE(s)\n", exeName);
  91         return 1;
  92     }
  93
  94     /* memory allocation for outFilename and resources */
  95     char* outFilename;
  96     size_t outFilenameBufferLen;
  97     resources const ress = createResources_orDie(argc, argv, &outFilename, &outFilenameBufferLen);
  98
  99     /* compress files with shared context, input and output buffers */
 100     int argNb;
 101     for (argNb = 1; argNb < argc; argNb++) {
 102         const char* const inFilename = argv[argNb];
 103         size_t const inFilenameLen = strlen(inFilename);
 104         CHECK(inFilenameLen + 5 <= outFilenameBufferLen, "File name too long!");
 105         memcpy(outFilename, inFilename, inFilenameLen);
 106         memcpy(outFilename+inFilenameLen, ".zst", 5);
 107         compressFile_orDie(ress, inFilename, outFilename);
 108     }
 109
 110     /* free memory */
 111     freeResources(ress,outFilename);
 112
 113     printf("compressed %i files \n", argc-1);
 114
 115     return 0;
 116 }