66 lines
2.3 KiB
C
66 lines
2.3 KiB
C
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/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#include <stdio.h> // printf
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#include <stdlib.h> // free
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#include <zstd.h> // presumes zstd library is installed
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#include "common.h" // Helper functions, CHECK(), and CHECK_ZSTD()
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static void decompress(const char* fname)
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{
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size_t cSize;
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void* const cBuff = mallocAndLoadFile_orDie(fname, &cSize);
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/* Read the content size from the frame header. For simplicity we require
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* that it is always present. By default, zstd will write the content size
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* in the header when it is known. If you can't guarantee that the frame
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* content size is always written into the header, either use streaming
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* decompression, or ZSTD_decompressBound().
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*/
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unsigned long long const rSize = ZSTD_getFrameContentSize(cBuff, cSize);
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CHECK(rSize != ZSTD_CONTENTSIZE_ERROR, "%s: not compressed by zstd!", fname);
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CHECK(rSize != ZSTD_CONTENTSIZE_UNKNOWN, "%s: original size unknown!", fname);
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void* const rBuff = malloc_orDie((size_t)rSize);
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/* Decompress.
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* If you are doing many decompressions, you may want to reuse the context
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* and use ZSTD_decompressDCtx(). If you want to set advanced parameters,
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* use ZSTD_DCtx_setParameter().
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*/
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size_t const dSize = ZSTD_decompress(rBuff, rSize, cBuff, cSize);
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CHECK_ZSTD(dSize);
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/* When zstd knows the content size, it will error if it doesn't match. */
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CHECK(dSize == rSize, "Impossible because zstd will check this condition!");
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/* success */
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printf("%25s : %6u -> %7u \n", fname, (unsigned)cSize, (unsigned)rSize);
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free(rBuff);
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free(cBuff);
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}
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int main(int argc, const char** argv)
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{
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const char* const exeName = argv[0];
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if (argc!=2) {
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printf("wrong arguments\n");
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printf("usage:\n");
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printf("%s FILE\n", exeName);
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return 1;
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}
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decompress(argv[1]);
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printf("%s correctly decoded (in memory). \n", argv[1]);
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return 0;
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}
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