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 
12 #include <stdio.h>     // printf
13 #include <stdlib.h>    // free
14 #include <string.h>    // memset, strcat, strlen
15 #include <zstd.h>      // presumes zstd library is installed
16 #include "common.h"    // Helper functions, CHECK(), and CHECK_ZSTD()
17 
18 static void compressFile_orDie(const char* fname, const char* outName, int cLevel,
19                                int nbThreads)
20 {
21     fprintf (stderr, "Starting compression of %s with level %d, using %d threads\n",
22              fname, cLevel, nbThreads);
23 
24     /* Open the input and output files. */
25     FILE* const fin  = fopen_orDie(fname, "rb");
26     FILE* const fout = fopen_orDie(outName, "wb");
27     /* Create the input and output buffers.
28      * They may be any size, but we recommend using these functions to size them.
29      * Performance will only suffer significantly for very tiny buffers.
30      */
31     size_t const buffInSize = ZSTD_CStreamInSize();
32     void*  const buffIn  = malloc_orDie(buffInSize);
33     size_t const buffOutSize = ZSTD_CStreamOutSize();
34     void*  const buffOut = malloc_orDie(buffOutSize);
35 
36     /* Create the context. */
37     ZSTD_CCtx* const cctx = ZSTD_createCCtx();
38     CHECK(cctx != NULL, "ZSTD_createCCtx() failed!");
39 
40     /* Set any parameters you want.
41      * Here we set the compression level, and enable the checksum.
42      */
43     CHECK_ZSTD( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel) );
44     CHECK_ZSTD( ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 1) );
45     ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, nbThreads);
46 
47     /* This loop read from the input file, compresses that entire chunk,
48      * and writes all output produced to the output file.
49      */
50     size_t const toRead = buffInSize;
51     for (;;) {
52         size_t read = fread_orDie(buffIn, toRead, fin);
53         /* Select the flush mode.
54          * If the read may not be finished (read == toRead) we use
55          * ZSTD_e_continue. If this is the last chunk, we use ZSTD_e_end.
56          * Zstd optimizes the case where the first flush mode is ZSTD_e_end,
57          * since it knows it is compressing the entire source in one pass.
58          */
59         int const lastChunk = (read < toRead);
60         ZSTD_EndDirective const mode = lastChunk ? ZSTD_e_end : ZSTD_e_continue;
61         /* Set the input buffer to what we just read.
62          * We compress until the input buffer is empty, each time flushing the
63          * output.
64          */
65         ZSTD_inBuffer input = { buffIn, read, 0 };
66         int finished;
67         do {
68             /* Compress into the output buffer and write all of the output to
69              * the file so we can reuse the buffer next iteration.
70              */
71             ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
72             size_t const remaining = ZSTD_compressStream2(cctx, &output , &input, mode);
73             CHECK_ZSTD(remaining);
74             fwrite_orDie(buffOut, output.pos, fout);
75             /* If we're on the last chunk we're finished when zstd returns 0,
76              * which means its consumed all the input AND finished the frame.
77              * Otherwise, we're finished when we've consumed all the input.
78              */
79             finished = lastChunk ? (remaining == 0) : (input.pos == input.size);
80         } while (!finished);
81         CHECK(input.pos == input.size,
82               "Impossible: zstd only returns 0 when the input is completely consumed!");
83 
84         if (lastChunk) {
85             break;
86         }
87     }
88 
89     ZSTD_freeCCtx(cctx);
90     fclose_orDie(fout);
91     fclose_orDie(fin);
92     free(buffIn);
93     free(buffOut);
94 }
95 
96 
97 static char* createOutFilename_orDie(const char* filename)
98 {
99     size_t const inL = strlen(filename);
100     size_t const outL = inL + 5;
101     void* const outSpace = malloc_orDie(outL);
102     memset(outSpace, 0, outL);
103     strcat(outSpace, filename);
104     strcat(outSpace, ".zst");
105     return (char*)outSpace;
106 }
107 
108 int main(int argc, const char** argv)
109 {
110     const char* const exeName = argv[0];
111 
112     if (argc < 2) {
113         printf("wrong arguments\n");
114         printf("usage:\n");
115         printf("%s FILE [LEVEL] [THREADS]\n", exeName);
116         return 1;
117     }
118 
119     int cLevel = 1;
120     int nbThreads = 4;
121 
122     if (argc >= 3) {
123       cLevel = atoi (argv[2]);
124       CHECK(cLevel != 0, "can't parse LEVEL!");
125     }
126 
127     if (argc >= 4) {
128       nbThreads = atoi (argv[3]);
129       CHECK(nbThreads != 0, "can't parse THREADS!");
130     }
131 
132     const char* const inFilename = argv[1];
133 
134     char* const outFilename = createOutFilename_orDie(inFilename);
135     compressFile_orDie(inFilename, outFilename, cLevel, nbThreads);
136 
137     free(outFilename);   /* not strictly required, since program execution stops there,
138                           * but some static analyzer may complain otherwise */
139     return 0;
140 }
141