xref: /freebsd/sys/contrib/zstd/examples/multiple_simple_compression.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
1 /*
2  * Copyright (c) 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 }
117