1 /* 2 * Copyright (c) 2016-2020, 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 19 static void compressFile_orDie(const char* fname, const char* outName, int cLevel) 20 { 21 /* Open the input and output files. */ 22 FILE* const fin = fopen_orDie(fname, "rb"); 23 FILE* const fout = fopen_orDie(outName, "wb"); 24 /* Create the input and output buffers. 25 * They may be any size, but we recommend using these functions to size them. 26 * Performance will only suffer significantly for very tiny buffers. 27 */ 28 size_t const buffInSize = ZSTD_CStreamInSize(); 29 void* const buffIn = malloc_orDie(buffInSize); 30 size_t const buffOutSize = ZSTD_CStreamOutSize(); 31 void* const buffOut = malloc_orDie(buffOutSize); 32 33 /* Create the context. */ 34 ZSTD_CCtx* const cctx = ZSTD_createCCtx(); 35 CHECK(cctx != NULL, "ZSTD_createCCtx() failed!"); 36 37 /* Set any parameters you want. 38 * Here we set the compression level, and enable the checksum. 39 */ 40 CHECK_ZSTD( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel) ); 41 CHECK_ZSTD( ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 1) ); 42 ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 4); 43 44 /* This loop read from the input file, compresses that entire chunk, 45 * and writes all output produced to the output file. 46 */ 47 size_t const toRead = buffInSize; 48 for (;;) { 49 size_t read = fread_orDie(buffIn, toRead, fin); 50 /* Select the flush mode. 51 * If the read may not be finished (read == toRead) we use 52 * ZSTD_e_continue. If this is the last chunk, we use ZSTD_e_end. 53 * Zstd optimizes the case where the first flush mode is ZSTD_e_end, 54 * since it knows it is compressing the entire source in one pass. 55 */ 56 int const lastChunk = (read < toRead); 57 ZSTD_EndDirective const mode = lastChunk ? ZSTD_e_end : ZSTD_e_continue; 58 /* Set the input buffer to what we just read. 59 * We compress until the input buffer is empty, each time flushing the 60 * output. 61 */ 62 ZSTD_inBuffer input = { buffIn, read, 0 }; 63 int finished; 64 do { 65 /* Compress into the output buffer and write all of the output to 66 * the file so we can reuse the buffer next iteration. 67 */ 68 ZSTD_outBuffer output = { buffOut, buffOutSize, 0 }; 69 size_t const remaining = ZSTD_compressStream2(cctx, &output , &input, mode); 70 CHECK_ZSTD(remaining); 71 fwrite_orDie(buffOut, output.pos, fout); 72 /* If we're on the last chunk we're finished when zstd returns 0, 73 * which means its consumed all the input AND finished the frame. 74 * Otherwise, we're finished when we've consumed all the input. 75 */ 76 finished = lastChunk ? (remaining == 0) : (input.pos == input.size); 77 } while (!finished); 78 CHECK(input.pos == input.size, 79 "Impossible: zstd only returns 0 when the input is completely consumed!"); 80 81 if (lastChunk) { 82 break; 83 } 84 } 85 86 ZSTD_freeCCtx(cctx); 87 fclose_orDie(fout); 88 fclose_orDie(fin); 89 free(buffIn); 90 free(buffOut); 91 } 92 93 94 static char* createOutFilename_orDie(const char* filename) 95 { 96 size_t const inL = strlen(filename); 97 size_t const outL = inL + 5; 98 void* const outSpace = malloc_orDie(outL); 99 memset(outSpace, 0, outL); 100 strcat(outSpace, filename); 101 strcat(outSpace, ".zst"); 102 return (char*)outSpace; 103 } 104 105 int main(int argc, const char** argv) 106 { 107 const char* const exeName = argv[0]; 108 109 if (argc!=2) { 110 printf("wrong arguments\n"); 111 printf("usage:\n"); 112 printf("%s FILE\n", exeName); 113 return 1; 114 } 115 116 const char* const inFilename = argv[1]; 117 118 char* const outFilename = createOutFilename_orDie(inFilename); 119 compressFile_orDie(inFilename, outFilename, 1); 120 121 free(outFilename); /* not strictly required, since program execution stops there, 122 * but some static analyzer main complain otherwise */ 123 return 0; 124 } 125