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 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 43 /* This loop read from the input file, compresses that entire chunk, 44 * and writes all output produced to the output file. 45 */ 46 size_t const toRead = buffInSize; 47 size_t read; 48 while ((read = fread_orDie(buffIn, toRead, fin))) { 49 /* Select the flush mode. 50 * If the read may not be finished (read == toRead) we use 51 * ZSTD_e_continue. If this is the last chunk, we use ZSTD_e_end. 52 * Zstd optimizes the case where the first flush mode is ZSTD_e_end, 53 * since it knows it is compressing the entire source in one pass. 54 */ 55 int const lastChunk = (read < toRead); 56 ZSTD_EndDirective const mode = lastChunk ? ZSTD_e_end : ZSTD_e_continue; 57 /* Set the input buffer to what we just read. 58 * We compress until the input buffer is empty, each time flushing the 59 * output. 60 */ 61 ZSTD_inBuffer input = { buffIn, read, 0 }; 62 int finished; 63 do { 64 /* Compress into the output buffer and write all of the output to 65 * the file so we can reuse the buffer next iteration. 66 */ 67 ZSTD_outBuffer output = { buffOut, buffOutSize, 0 }; 68 size_t const remaining = ZSTD_compressStream2(cctx, &output , &input, mode); 69 CHECK_ZSTD(remaining); 70 fwrite_orDie(buffOut, output.pos, fout); 71 /* If we're on the last chunk we're finished when zstd returns 0, 72 * which means its consumed all the input AND finished the frame. 73 * Otherwise, we're finished when we've consumed all the input. 74 */ 75 finished = lastChunk ? (remaining == 0) : (input.pos == input.size); 76 } while (!finished); 77 CHECK(input.pos == input.size, 78 "Impossible: zstd only returns 0 when the input is completely consumed!"); 79 } 80 81 ZSTD_freeCCtx(cctx); 82 fclose_orDie(fout); 83 fclose_orDie(fin); 84 free(buffIn); 85 free(buffOut); 86 } 87 88 89 static char* createOutFilename_orDie(const char* filename) 90 { 91 size_t const inL = strlen(filename); 92 size_t const outL = inL + 5; 93 void* const outSpace = malloc_orDie(outL); 94 memset(outSpace, 0, outL); 95 strcat(outSpace, filename); 96 strcat(outSpace, ".zst"); 97 return (char*)outSpace; 98 } 99 100 int main(int argc, const char** argv) 101 { 102 const char* const exeName = argv[0]; 103 104 if (argc!=2) { 105 printf("wrong arguments\n"); 106 printf("usage:\n"); 107 printf("%s FILE\n", exeName); 108 return 1; 109 } 110 111 const char* const inFilename = argv[1]; 112 113 char* const outFilename = createOutFilename_orDie(inFilename); 114 compressFile_orDie(inFilename, outFilename, 1); 115 116 free(outFilename); /* not strictly required, since program execution stops there, 117 * but some static analyzer main complain otherwise */ 118 return 0; 119 } 120