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https://github.com/facebook/zstd.git
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89 lines
3.6 KiB
C
89 lines
3.6 KiB
C
/*
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* Copyright (c) 2016-2021, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
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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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#ifndef ZSTD_ZLIBWRAPPER_H
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#define ZSTD_ZLIBWRAPPER_H
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#if defined (__cplusplus)
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extern "C" {
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#endif
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#define ZLIB_CONST
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#define Z_PREFIX
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#define ZLIB_INTERNAL /* disables gz*64 functions but fixes zlib 1.2.4 with Z_PREFIX */
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#include <zlib.h>
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#if !defined(z_const)
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#define z_const
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#endif
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/* returns a string with version of zstd library */
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const char * zstdVersion(void);
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/*** COMPRESSION ***/
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/* ZWRAP_useZSTDcompression() enables/disables zstd compression during runtime.
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By default zstd compression is disabled. To enable zstd compression please use one of the methods:
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- compilation with the additional option -DZWRAP_USE_ZSTD=1
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- using '#define ZWRAP_USE_ZSTD 1' in source code before '#include "zstd_zlibwrapper.h"'
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- calling ZWRAP_useZSTDcompression(1)
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All above-mentioned methods will enable zstd compression for all threads.
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Be aware that ZWRAP_useZSTDcompression() is not thread-safe and may lead to a race condition. */
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void ZWRAP_useZSTDcompression(int turn_on);
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/* checks if zstd compression is turned on */
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int ZWRAP_isUsingZSTDcompression(void);
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/* Changes a pledged source size for a given compression stream.
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It will change ZSTD compression parameters what may improve compression speed and/or ratio.
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The function should be called just after deflateInit() or deflateReset() and before deflate() or deflateSetDictionary().
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It's only helpful when data is compressed in blocks.
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There will be no change in case of deflateInit() or deflateReset() immediately followed by deflate(strm, Z_FINISH)
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as this case is automatically detected. */
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int ZWRAP_setPledgedSrcSize(z_streamp strm, unsigned long long pledgedSrcSize);
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/* Similar to deflateReset but preserves dictionary set using deflateSetDictionary.
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It should improve compression speed because there will be less calls to deflateSetDictionary
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When using zlib compression this method redirects to deflateReset. */
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int ZWRAP_deflateReset_keepDict(z_streamp strm);
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/*** DECOMPRESSION ***/
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typedef enum { ZWRAP_FORCE_ZLIB, ZWRAP_AUTO } ZWRAP_decompress_type;
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/* ZWRAP_setDecompressionType() enables/disables automatic recognition of zstd/zlib compressed data during runtime.
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By default auto-detection of zstd and zlib streams in enabled (ZWRAP_AUTO).
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Forcing zlib decompression with ZWRAP_setDecompressionType(ZWRAP_FORCE_ZLIB) slightly improves
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decompression speed of zlib-encoded streams.
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Be aware that ZWRAP_setDecompressionType() is not thread-safe and may lead to a race condition. */
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void ZWRAP_setDecompressionType(ZWRAP_decompress_type type);
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/* checks zstd decompression type */
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ZWRAP_decompress_type ZWRAP_getDecompressionType(void);
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/* Checks if zstd decompression is used for a given stream.
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If will return 1 only when inflate() was called and zstd header was detected. */
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int ZWRAP_isUsingZSTDdecompression(z_streamp strm);
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/* Similar to inflateReset but preserves dictionary set using inflateSetDictionary.
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inflate() will return Z_NEED_DICT only for the first time what will improve decompression speed.
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For zlib streams this method redirects to inflateReset. */
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int ZWRAP_inflateReset_keepDict(z_streamp strm);
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#if defined (__cplusplus)
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}
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#endif
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#endif /* ZSTD_ZLIBWRAPPER_H */
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