| /* |
| * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc. |
| * All rights reserved. |
| * |
| * This source code is licensed under both the BSD-style license (found in the |
| * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| * in the COPYING file in the root directory of this source tree). |
| * You may select, at your option, one of the above-listed licenses. |
| */ |
| |
| |
| #include <stdio.h> // printf |
| #include <stdlib.h> // free |
| #include <zstd.h> // presumes zstd library is installed |
| #include "common.h" // Helper functions, CHECK(), and CHECK_ZSTD() |
| |
| /* createDict() : |
| `dictFileName` is supposed to have been created using `zstd --train` */ |
| static ZSTD_DDict* createDict_orDie(const char* dictFileName) |
| { |
| size_t dictSize; |
| printf("loading dictionary %s \n", dictFileName); |
| void* const dictBuffer = mallocAndLoadFile_orDie(dictFileName, &dictSize); |
| ZSTD_DDict* const ddict = ZSTD_createDDict(dictBuffer, dictSize); |
| CHECK(ddict != NULL, "ZSTD_createDDict() failed!"); |
| free(dictBuffer); |
| return ddict; |
| } |
| |
| static void decompress(const char* fname, const ZSTD_DDict* ddict) |
| { |
| size_t cSize; |
| void* const cBuff = mallocAndLoadFile_orDie(fname, &cSize); |
| /* Read the content size from the frame header. For simplicity we require |
| * that it is always present. By default, zstd will write the content size |
| * in the header when it is known. If you can't guarantee that the frame |
| * content size is always written into the header, either use streaming |
| * decompression, or ZSTD_decompressBound(). |
| */ |
| unsigned long long const rSize = ZSTD_getFrameContentSize(cBuff, cSize); |
| CHECK(rSize != ZSTD_CONTENTSIZE_ERROR, "%s: not compressed by zstd!", fname); |
| CHECK(rSize != ZSTD_CONTENTSIZE_UNKNOWN, "%s: original size unknown!", fname); |
| void* const rBuff = malloc_orDie((size_t)rSize); |
| |
| /* Check that the dictionary ID matches. |
| * If a non-zstd dictionary is used, then both will be zero. |
| * By default zstd always writes the dictionary ID into the frame. |
| * Zstd will check if there is a dictionary ID mismatch as well. |
| */ |
| unsigned const expectedDictID = ZSTD_getDictID_fromDDict(ddict); |
| unsigned const actualDictID = ZSTD_getDictID_fromFrame(cBuff, cSize); |
| CHECK(actualDictID == expectedDictID, |
| "DictID mismatch: expected %u got %u", |
| expectedDictID, |
| actualDictID); |
| |
| /* Decompress using the dictionary. |
| * If you need to control the decompression parameters, then use the |
| * advanced API: ZSTD_DCtx_setParameter(), ZSTD_DCtx_refDDict(), and |
| * ZSTD_decompressDCtx(). |
| */ |
| ZSTD_DCtx* const dctx = ZSTD_createDCtx(); |
| CHECK(dctx != NULL, "ZSTD_createDCtx() failed!"); |
| size_t const dSize = ZSTD_decompress_usingDDict(dctx, rBuff, rSize, cBuff, cSize, ddict); |
| CHECK_ZSTD(dSize); |
| /* When zstd knows the content size, it will error if it doesn't match. */ |
| CHECK(dSize == rSize, "Impossible because zstd will check this condition!"); |
| |
| /* success */ |
| printf("%25s : %6u -> %7u \n", fname, (unsigned)cSize, (unsigned)rSize); |
| |
| ZSTD_freeDCtx(dctx); |
| free(rBuff); |
| free(cBuff); |
| } |
| |
| |
| int main(int argc, const char** argv) |
| { |
| const char* const exeName = argv[0]; |
| |
| if (argc<3) { |
| printf("wrong arguments\n"); |
| printf("usage:\n"); |
| printf("%s [FILES] dictionary\n", exeName); |
| return 1; |
| } |
| |
| /* load dictionary only once */ |
| const char* const dictName = argv[argc-1]; |
| ZSTD_DDict* const dictPtr = createDict_orDie(dictName); |
| |
| int u; |
| for (u=1; u<argc-1; u++) decompress(argv[u], dictPtr); |
| |
| ZSTD_freeDDict(dictPtr); |
| printf("All %u files correctly decoded (in memory) \n", argc-2); |
| return 0; |
| } |