197 lines
9.8 KiB
C
197 lines
9.8 KiB
C
/*
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LZ4 HC - High Compression Mode of LZ4
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Header File
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Copyright (C) 2011-2015, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- LZ4 source repository : https://github.com/Cyan4973/lz4
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- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
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*/
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#ifndef LZ4_HC_H_19834876238432
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#define LZ4_HC_H_19834876238432
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#if defined (__cplusplus)
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extern "C" {
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#endif
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/*-***************************
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* Includes
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*****************************/
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#include <stddef.h> /* size_t */
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#define LZ4HC_MIN_CLEVEL 3
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#define LZ4HC_DEFAULT_CLEVEL 9
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#define LZ4HC_MAX_CLEVEL 16
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/*-************************************
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* Block Compression
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**************************************/
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/*!
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LZ4_compress_HC() :
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Destination buffer `dst` must be already allocated.
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Compression success is guaranteed if `dst` buffer is sized to handle worst circumstances (data not compressible)
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Worst size evaluation is provided by function LZ4_compressBound() (see "lz4.h")
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`srcSize` : Max supported value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
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`compressionLevel` : Recommended values are between 4 and 9, although any value between 0 and LZ4HC_MAX_CLEVEL will work.
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0 means "use default value" (see lz4hc.c).
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Values >LZ4HC_MAX_CLEVEL behave the same as 16.
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@return : the number of bytes written into buffer 'dst'
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or 0 if compression fails.
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*/
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int LZ4_compress_HC (const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
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/* Note :
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Decompression functions are provided within "lz4.h" (BSD license)
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*/
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/*!
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LZ4_compress_HC_extStateHC() :
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Use this function if you prefer to manually allocate memory for compression tables.
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To know how much memory must be allocated for the compression tables, use :
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int LZ4_sizeofStateHC();
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Allocated memory must be aligned on 8-bytes boundaries (which a normal malloc() will do properly).
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The allocated memory can then be provided to the compression functions using 'void* state' parameter.
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LZ4_compress_HC_extStateHC() is equivalent to previously described function.
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It just uses externally allocated memory for stateHC.
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*/
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int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
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int LZ4_sizeofStateHC(void);
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/*-************************************
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* Streaming Compression
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**************************************/
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#define LZ4_STREAMHCSIZE 262192
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#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
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typedef struct { size_t table[LZ4_STREAMHCSIZE_SIZET]; } LZ4_streamHC_t;
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/*
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LZ4_streamHC_t
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This structure allows static allocation of LZ4 HC streaming state.
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State must then be initialized using LZ4_resetStreamHC() before first use.
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Static allocation should only be used in combination with static linking.
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If you want to use LZ4 as a DLL, please use construction functions below, which are future-proof.
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*/
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/*! LZ4_createStreamHC() and LZ4_freeStreamHC() :
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These functions create and release memory for LZ4 HC streaming state.
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Newly created states are already initialized.
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Existing state space can be re-used anytime using LZ4_resetStreamHC().
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If you use LZ4 as a DLL, use these functions instead of static structure allocation,
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to avoid size mismatch between different versions.
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*/
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LZ4_streamHC_t* LZ4_createStreamHC(void);
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int LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
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void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
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int LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize);
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int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize);
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int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize);
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/*
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These functions compress data in successive blocks of any size, using previous blocks as dictionary.
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One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks.
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There is an exception for ring buffers, which can be smaller than 64 KB.
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Such case is automatically detected and correctly handled by LZ4_compress_HC_continue().
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Before starting compression, state must be properly initialized, using LZ4_resetStreamHC().
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A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional).
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Then, use LZ4_compress_HC_continue() to compress each successive block.
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It works like LZ4_compress_HC(), but use previous memory blocks as dictionary to improve compression.
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Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression.
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As a reminder, size 'dst' buffer to handle worst cases, using LZ4_compressBound(), to ensure success of compression operation.
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If, for any reason, previous data blocks can't be preserved unmodified in memory during next compression block,
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you must save it to a safer memory space, using LZ4_saveDictHC().
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Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer'.
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*/
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/*-************************************
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* Deprecated Functions
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**************************************/
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/* Deprecate Warnings */
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/* Should these warnings messages be a problem,
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it is generally possible to disable them,
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with -Wno-deprecated-declarations for gcc
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or _CRT_SECURE_NO_WARNINGS in Visual for example.
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You can also define LZ4_DEPRECATE_WARNING_DEFBLOCK. */
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#ifndef LZ4_DEPRECATE_WARNING_DEFBLOCK
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# define LZ4_DEPRECATE_WARNING_DEFBLOCK
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# define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
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# if (LZ4_GCC_VERSION >= 405) || defined(__clang__)
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# define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
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# elif (LZ4_GCC_VERSION >= 301)
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# define LZ4_DEPRECATED(message) __attribute__((deprecated))
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# elif defined(_MSC_VER)
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# define LZ4_DEPRECATED(message) __declspec(deprecated(message))
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# else
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# pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler")
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# define LZ4_DEPRECATED(message)
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# endif
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#endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */
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/* deprecated compression functions */
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/* these functions will trigger warning messages in future releases */
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int LZ4_compressHC (const char* source, char* dest, int inputSize);
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int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
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LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
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LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
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int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize);
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int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
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LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
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LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
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int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
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int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
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/* Deprecated Streaming functions using older model; should no longer be used */
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LZ4_DEPRECATED("use LZ4_createStreamHC() instead") void* LZ4_createHC (char* inputBuffer);
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LZ4_DEPRECATED("use LZ4_saveDictHC() instead") char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
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LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") int LZ4_freeHC (void* LZ4HC_Data);
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LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
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LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
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LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int LZ4_sizeofStreamStateHC(void);
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LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStreamStateHC(void* state, char* inputBuffer);
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#if defined (__cplusplus)
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}
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#endif
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#endif /* LZ4_HC_H_19834876238432 */
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