1*01826a49SYabin Cui /*
2*01826a49SYabin Cui * Copyright (c) Meta Platforms, Inc. and affiliates.
3*01826a49SYabin Cui * All rights reserved.
4*01826a49SYabin Cui *
5*01826a49SYabin Cui * This source code is licensed under both the BSD-style license (found in the
6*01826a49SYabin Cui * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7*01826a49SYabin Cui * in the COPYING file in the root directory of this source tree).
8*01826a49SYabin Cui * You may select, at your option, one of the above-listed licenses.
9*01826a49SYabin Cui */
10*01826a49SYabin Cui
11*01826a49SYabin Cui
12*01826a49SYabin Cui /* The objective of this example is to show of to compress multiple successive files
13*01826a49SYabin Cui * while preserving memory management.
14*01826a49SYabin Cui * All structures and buffers will be created only once,
15*01826a49SYabin Cui * and shared across all compression operations */
16*01826a49SYabin Cui
17*01826a49SYabin Cui #include <stdio.h> // printf
18*01826a49SYabin Cui #include <stdlib.h> // free
19*01826a49SYabin Cui #include <string.h> // memset, strcat
20*01826a49SYabin Cui #include <zstd.h> // presumes zstd library is installed
21*01826a49SYabin Cui #include "common.h" // Helper functions, CHECK(), and CHECK_ZSTD()
22*01826a49SYabin Cui
23*01826a49SYabin Cui typedef struct {
24*01826a49SYabin Cui void* buffIn;
25*01826a49SYabin Cui void* buffOut;
26*01826a49SYabin Cui size_t buffInSize;
27*01826a49SYabin Cui size_t buffOutSize;
28*01826a49SYabin Cui ZSTD_CCtx* cctx;
29*01826a49SYabin Cui } resources;
30*01826a49SYabin Cui
createResources_orDie(int cLevel)31*01826a49SYabin Cui static resources createResources_orDie(int cLevel)
32*01826a49SYabin Cui {
33*01826a49SYabin Cui resources ress;
34*01826a49SYabin Cui ress.buffInSize = ZSTD_CStreamInSize(); /* can always read one full block */
35*01826a49SYabin Cui ress.buffOutSize= ZSTD_CStreamOutSize(); /* can always flush a full block */
36*01826a49SYabin Cui ress.buffIn = malloc_orDie(ress.buffInSize);
37*01826a49SYabin Cui ress.buffOut= malloc_orDie(ress.buffOutSize);
38*01826a49SYabin Cui ress.cctx = ZSTD_createCCtx();
39*01826a49SYabin Cui CHECK(ress.cctx != NULL, "ZSTD_createCCtx() failed!");
40*01826a49SYabin Cui
41*01826a49SYabin Cui /* Set any compression parameters you want here.
42*01826a49SYabin Cui * They will persist for every compression operation.
43*01826a49SYabin Cui * Here we set the compression level, and enable the checksum.
44*01826a49SYabin Cui */
45*01826a49SYabin Cui CHECK_ZSTD( ZSTD_CCtx_setParameter(ress.cctx, ZSTD_c_compressionLevel, cLevel) );
46*01826a49SYabin Cui CHECK_ZSTD( ZSTD_CCtx_setParameter(ress.cctx, ZSTD_c_checksumFlag, 1) );
47*01826a49SYabin Cui return ress;
48*01826a49SYabin Cui }
49*01826a49SYabin Cui
freeResources(resources ress)50*01826a49SYabin Cui static void freeResources(resources ress)
51*01826a49SYabin Cui {
52*01826a49SYabin Cui ZSTD_freeCCtx(ress.cctx);
53*01826a49SYabin Cui free(ress.buffIn);
54*01826a49SYabin Cui free(ress.buffOut);
55*01826a49SYabin Cui }
56*01826a49SYabin Cui
compressFile_orDie(resources ress,const char * fname,const char * outName)57*01826a49SYabin Cui static void compressFile_orDie(resources ress, const char* fname, const char* outName)
58*01826a49SYabin Cui {
59*01826a49SYabin Cui // Open the input and output files.
60*01826a49SYabin Cui FILE* const fin = fopen_orDie(fname, "rb");
61*01826a49SYabin Cui FILE* const fout = fopen_orDie(outName, "wb");
62*01826a49SYabin Cui
63*01826a49SYabin Cui /* Reset the context to a clean state to start a new compression operation.
64*01826a49SYabin Cui * The parameters are sticky, so we keep the compression level and extra
65*01826a49SYabin Cui * parameters that we set in createResources_orDie().
66*01826a49SYabin Cui */
67*01826a49SYabin Cui CHECK_ZSTD( ZSTD_CCtx_reset(ress.cctx, ZSTD_reset_session_only) );
68*01826a49SYabin Cui
69*01826a49SYabin Cui size_t const toRead = ress.buffInSize;
70*01826a49SYabin Cui size_t read;
71*01826a49SYabin Cui while ( (read = fread_orDie(ress.buffIn, toRead, fin)) ) {
72*01826a49SYabin Cui /* This loop is the same as streaming_compression.c.
73*01826a49SYabin Cui * See that file for detailed comments.
74*01826a49SYabin Cui */
75*01826a49SYabin Cui int const lastChunk = (read < toRead);
76*01826a49SYabin Cui ZSTD_EndDirective const mode = lastChunk ? ZSTD_e_end : ZSTD_e_continue;
77*01826a49SYabin Cui
78*01826a49SYabin Cui ZSTD_inBuffer input = { ress.buffIn, read, 0 };
79*01826a49SYabin Cui int finished;
80*01826a49SYabin Cui do {
81*01826a49SYabin Cui ZSTD_outBuffer output = { ress.buffOut, ress.buffOutSize, 0 };
82*01826a49SYabin Cui size_t const remaining = ZSTD_compressStream2(ress.cctx, &output, &input, mode);
83*01826a49SYabin Cui CHECK_ZSTD(remaining);
84*01826a49SYabin Cui fwrite_orDie(ress.buffOut, output.pos, fout);
85*01826a49SYabin Cui finished = lastChunk ? (remaining == 0) : (input.pos == input.size);
86*01826a49SYabin Cui } while (!finished);
87*01826a49SYabin Cui CHECK(input.pos == input.size,
88*01826a49SYabin Cui "Impossible: zstd only returns 0 when the input is completely consumed!");
89*01826a49SYabin Cui }
90*01826a49SYabin Cui
91*01826a49SYabin Cui fclose_orDie(fout);
92*01826a49SYabin Cui fclose_orDie(fin);
93*01826a49SYabin Cui }
94*01826a49SYabin Cui
main(int argc,const char ** argv)95*01826a49SYabin Cui int main(int argc, const char** argv)
96*01826a49SYabin Cui {
97*01826a49SYabin Cui const char* const exeName = argv[0];
98*01826a49SYabin Cui
99*01826a49SYabin Cui if (argc<2) {
100*01826a49SYabin Cui printf("wrong arguments\n");
101*01826a49SYabin Cui printf("usage:\n");
102*01826a49SYabin Cui printf("%s FILE(s)\n", exeName);
103*01826a49SYabin Cui return 1;
104*01826a49SYabin Cui }
105*01826a49SYabin Cui
106*01826a49SYabin Cui int const cLevel = 7;
107*01826a49SYabin Cui resources const ress = createResources_orDie(cLevel);
108*01826a49SYabin Cui void* ofnBuffer = NULL;
109*01826a49SYabin Cui size_t ofnbSize = 0;
110*01826a49SYabin Cui
111*01826a49SYabin Cui int argNb;
112*01826a49SYabin Cui for (argNb = 1; argNb < argc; argNb++) {
113*01826a49SYabin Cui const char* const ifn = argv[argNb];
114*01826a49SYabin Cui size_t const ifnSize = strlen(ifn);
115*01826a49SYabin Cui size_t const ofnSize = ifnSize + 5;
116*01826a49SYabin Cui if (ofnbSize <= ofnSize) {
117*01826a49SYabin Cui ofnbSize = ofnSize + 16;
118*01826a49SYabin Cui free(ofnBuffer);
119*01826a49SYabin Cui ofnBuffer = malloc_orDie(ofnbSize);
120*01826a49SYabin Cui }
121*01826a49SYabin Cui memset(ofnBuffer, 0, ofnSize);
122*01826a49SYabin Cui strcat(ofnBuffer, ifn);
123*01826a49SYabin Cui strcat(ofnBuffer, ".zst");
124*01826a49SYabin Cui compressFile_orDie(ress, ifn, ofnBuffer);
125*01826a49SYabin Cui }
126*01826a49SYabin Cui
127*01826a49SYabin Cui freeResources(ress);
128*01826a49SYabin Cui free(ofnBuffer);
129*01826a49SYabin Cui
130*01826a49SYabin Cui printf("compressed %i files \n", argc-1);
131*01826a49SYabin Cui
132*01826a49SYabin Cui return 0;
133*01826a49SYabin Cui }
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