624 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			624 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /*
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|    LZ4 auto-framing library
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|    Header File
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|    Copyright (C) 2011-2017, Yann Collet.
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|    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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| 
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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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| 
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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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| 
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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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| 
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|    You can contact the author at :
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|    - LZ4 source repository : https://github.com/lz4/lz4
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|    - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
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| */
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| 
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| /* LZ4F is a stand-alone API able to create and decode LZ4 frames
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|  * conformant with specification v1.6.1 in doc/lz4_Frame_format.md .
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|  * Generated frames are compatible with `lz4` CLI.
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|  *
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|  * LZ4F also offers streaming capabilities.
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|  *
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|  * lz4.h is not required when using lz4frame.h,
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|  * except to extract common constant such as LZ4_VERSION_NUMBER.
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|  * */
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| 
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| #ifndef LZ4F_H_09782039843
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| #define LZ4F_H_09782039843
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| 
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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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| /* ---   Dependency   --- */
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| #include <stddef.h>   /* size_t */
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| 
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| 
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| /**
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|   Introduction
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| 
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|   lz4frame.h implements LZ4 frame specification (doc/lz4_Frame_format.md).
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|   lz4frame.h provides frame compression functions that take care
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|   of encoding standard metadata alongside LZ4-compressed blocks.
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| */
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| 
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| /*-***************************************************************
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|  *  Compiler specifics
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|  *****************************************************************/
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| /*  LZ4_DLL_EXPORT :
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|  *  Enable exporting of functions when building a Windows DLL
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|  *  LZ4FLIB_VISIBILITY :
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|  *  Control library symbols visibility.
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|  */
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| #ifndef LZ4FLIB_VISIBILITY
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| #  if defined(__GNUC__) && (__GNUC__ >= 4)
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| #    define LZ4FLIB_VISIBILITY __attribute__ ((visibility ("default")))
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| #  else
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| #    define LZ4FLIB_VISIBILITY
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| #  endif
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| #endif
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| #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
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| #  define LZ4FLIB_API __declspec(dllexport) LZ4FLIB_VISIBILITY
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| #elif 1 && defined(_MSC_VER)
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| #  define LZ4FLIB_API __declspec(dllimport) LZ4FLIB_VISIBILITY
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| #else
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| #  define LZ4FLIB_API LZ4FLIB_VISIBILITY
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| #endif
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| 
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| #ifdef LZ4F_DISABLE_DEPRECATE_WARNINGS
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| #  define LZ4F_DEPRECATE(x) x
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| #else
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| #  if defined(_MSC_VER)
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| #    define LZ4F_DEPRECATE(x) x   /* __declspec(deprecated) x - only works with C++ */
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| #  elif defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 6))
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| #    define LZ4F_DEPRECATE(x) x __attribute__((deprecated))
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| #  else
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| #    define LZ4F_DEPRECATE(x) x   /* no deprecation warning for this compiler */
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| #  endif
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| #endif
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| 
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| 
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| /*-************************************
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|  *  Error management
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|  **************************************/
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| typedef size_t LZ4F_errorCode_t;
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| 
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| LZ4FLIB_API unsigned    LZ4F_isError(LZ4F_errorCode_t code);   /**< tells when a function result is an error code */
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| LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code);   /**< return error code string; for debugging */
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| 
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| 
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| /*-************************************
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|  *  Frame compression types
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|  ************************************* */
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| /* #define LZ4F_ENABLE_OBSOLETE_ENUMS   // uncomment to enable obsolete enums */
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| #ifdef LZ4F_ENABLE_OBSOLETE_ENUMS
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| #  define LZ4F_OBSOLETE_ENUM(x) , LZ4F_DEPRECATE(x) = LZ4F_##x
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| #else
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| #  define LZ4F_OBSOLETE_ENUM(x)
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| #endif
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| 
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| /* The larger the block size, the (slightly) better the compression ratio,
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|  * though there are diminishing returns.
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|  * Larger blocks also increase memory usage on both compression and decompression sides.
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|  */
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| typedef enum {
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|     LZ4F_default=0,
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|     LZ4F_max64KB=4,
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|     LZ4F_max256KB=5,
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|     LZ4F_max1MB=6,
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|     LZ4F_max4MB=7
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|     LZ4F_OBSOLETE_ENUM(max64KB)
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|     LZ4F_OBSOLETE_ENUM(max256KB)
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|     LZ4F_OBSOLETE_ENUM(max1MB)
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|     LZ4F_OBSOLETE_ENUM(max4MB)
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| } LZ4F_blockSizeID_t;
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| 
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| /* Linked blocks sharply reduce inefficiencies when using small blocks,
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|  * they compress better.
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|  * However, some LZ4 decoders are only compatible with independent blocks */
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| typedef enum {
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|     LZ4F_blockLinked=0,
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|     LZ4F_blockIndependent
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|     LZ4F_OBSOLETE_ENUM(blockLinked)
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|     LZ4F_OBSOLETE_ENUM(blockIndependent)
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| } LZ4F_blockMode_t;
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| 
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| typedef enum {
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|     LZ4F_noContentChecksum=0,
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|     LZ4F_contentChecksumEnabled
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|     LZ4F_OBSOLETE_ENUM(noContentChecksum)
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|     LZ4F_OBSOLETE_ENUM(contentChecksumEnabled)
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| } LZ4F_contentChecksum_t;
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| 
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| typedef enum {
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|     LZ4F_noBlockChecksum=0,
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|     LZ4F_blockChecksumEnabled
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| } LZ4F_blockChecksum_t;
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| 
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| typedef enum {
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|     LZ4F_frame=0,
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|     LZ4F_skippableFrame
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|     LZ4F_OBSOLETE_ENUM(skippableFrame)
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| } LZ4F_frameType_t;
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| 
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| #ifdef LZ4F_ENABLE_OBSOLETE_ENUMS
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| typedef LZ4F_blockSizeID_t blockSizeID_t;
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| typedef LZ4F_blockMode_t blockMode_t;
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| typedef LZ4F_frameType_t frameType_t;
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| typedef LZ4F_contentChecksum_t contentChecksum_t;
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| #endif
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| 
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| /*! LZ4F_frameInfo_t :
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|  *  makes it possible to set or read frame parameters.
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|  *  Structure must be first init to 0, using memset() or LZ4F_INIT_FRAMEINFO,
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|  *  setting all parameters to default.
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|  *  It's then possible to update selectively some parameters */
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| typedef struct {
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|   LZ4F_blockSizeID_t     blockSizeID;         /* max64KB, max256KB, max1MB, max4MB; 0 == default */
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|   LZ4F_blockMode_t       blockMode;           /* LZ4F_blockLinked, LZ4F_blockIndependent; 0 == default */
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|   LZ4F_contentChecksum_t contentChecksumFlag; /* 1: frame terminated with 32-bit checksum of decompressed data; 0: disabled (default) */
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|   LZ4F_frameType_t       frameType;           /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
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|   unsigned long long     contentSize;         /* Size of uncompressed content ; 0 == unknown */
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|   unsigned               dictID;              /* Dictionary ID, sent by compressor to help decoder select correct dictionary; 0 == no dictID provided */
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|   LZ4F_blockChecksum_t   blockChecksumFlag;   /* 1: each block followed by a checksum of block's compressed data; 0: disabled (default) */
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| } LZ4F_frameInfo_t;
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| 
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| #define LZ4F_INIT_FRAMEINFO   { LZ4F_default, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame, 0ULL, 0U, LZ4F_noBlockChecksum }    /* v1.8.3+ */
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| 
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| /*! LZ4F_preferences_t :
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|  *  makes it possible to supply advanced compression instructions to streaming interface.
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|  *  Structure must be first init to 0, using memset() or LZ4F_INIT_PREFERENCES,
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|  *  setting all parameters to default.
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|  *  All reserved fields must be set to zero. */
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| typedef struct {
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|   LZ4F_frameInfo_t frameInfo;
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|   int      compressionLevel;    /* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */
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|   unsigned autoFlush;           /* 1: always flush; reduces usage of internal buffers */
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|   unsigned favorDecSpeed;       /* 1: parser favors decompression speed vs compression ratio. Only works for high compression modes (>= LZ4HC_CLEVEL_OPT_MIN) */  /* v1.8.2+ */
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|   unsigned reserved[3];         /* must be zero for forward compatibility */
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| } LZ4F_preferences_t;
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| 
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| #define LZ4F_INIT_PREFERENCES   { LZ4F_INIT_FRAMEINFO, 0, 0u, 0u, { 0u, 0u, 0u } }    /* v1.8.3+ */
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| 
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| 
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| /*-*********************************
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| *  Simple compression function
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| ***********************************/
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| 
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| LZ4FLIB_API int LZ4F_compressionLevel_max(void);   /* v1.8.0+ */
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| 
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| /*! LZ4F_compressFrameBound() :
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|  *  Returns the maximum possible compressed size with LZ4F_compressFrame() given srcSize and preferences.
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|  * `preferencesPtr` is optional. It can be replaced by NULL, in which case, the function will assume default preferences.
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|  *  Note : this result is only usable with LZ4F_compressFrame().
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|  *         It may also be used with LZ4F_compressUpdate() _if no flush() operation_ is performed.
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|  */
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| LZ4FLIB_API size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr);
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| 
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| /*! LZ4F_compressFrame() :
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|  *  Compress an entire srcBuffer into a valid LZ4 frame.
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|  *  dstCapacity MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
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|  *  The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
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|  * @return : number of bytes written into dstBuffer.
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|  *           or an error code if it fails (can be tested using LZ4F_isError())
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|  */
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| LZ4FLIB_API size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
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|                                 const void* srcBuffer, size_t srcSize,
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|                                 const LZ4F_preferences_t* preferencesPtr);
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| 
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| 
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| /*-***********************************
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| *  Advanced compression functions
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| *************************************/
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| typedef struct LZ4F_cctx_s LZ4F_cctx;   /* incomplete type */
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| typedef LZ4F_cctx* LZ4F_compressionContext_t;   /* for compatibility with previous API version */
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| 
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| typedef struct {
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|   unsigned stableSrc;    /* 1 == src content will remain present on future calls to LZ4F_compress(); skip copying src content within tmp buffer */
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|   unsigned reserved[3];
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| } LZ4F_compressOptions_t;
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| 
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| /*---   Resource Management   ---*/
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| 
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| #define LZ4F_VERSION 100    /* This number can be used to check for an incompatible API breaking change */
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| LZ4FLIB_API unsigned LZ4F_getVersion(void);
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| 
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| /*! LZ4F_createCompressionContext() :
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|  * The first thing to do is to create a compressionContext object, which will be used in all compression operations.
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|  * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version.
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|  * The version provided MUST be LZ4F_VERSION. It is intended to track potential version mismatch, notably when using DLL.
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|  * The function will provide a pointer to a fully allocated LZ4F_cctx object.
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|  * If @return != zero, there was an error during context creation.
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|  * Object can release its memory using LZ4F_freeCompressionContext();
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|  */
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| LZ4FLIB_API LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** cctxPtr, unsigned version);
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| LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
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| 
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| 
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| /*----    Compression    ----*/
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| 
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| #define LZ4F_HEADER_SIZE_MIN  7   /* LZ4 Frame header size can vary, depending on selected paramaters */
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| #define LZ4F_HEADER_SIZE_MAX 19
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| 
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| /* Size in bytes of a block header in little-endian format. Highest bit indicates if block data is uncompressed */
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| #define LZ4F_BLOCK_HEADER_SIZE 4
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| 
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| /* Size in bytes of a block checksum footer in little-endian format. */
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| #define LZ4F_BLOCK_CHECKSUM_SIZE 4
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| 
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| /* Size in bytes of the content checksum. */
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| #define LZ4F_CONTENT_CHECKSUM_SIZE 4
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| 
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| /*! LZ4F_compressBegin() :
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|  *  will write the frame header into dstBuffer.
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|  *  dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
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|  * `prefsPtr` is optional : you can provide NULL as argument, all preferences will then be set to default.
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|  * @return : number of bytes written into dstBuffer for the header
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|  *           or an error code (which can be tested using LZ4F_isError())
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|  */
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| LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
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|                                       void* dstBuffer, size_t dstCapacity,
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|                                       const LZ4F_preferences_t* prefsPtr);
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| 
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| /*! LZ4F_compressBound() :
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|  *  Provides minimum dstCapacity required to guarantee success of
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|  *  LZ4F_compressUpdate(), given a srcSize and preferences, for a worst case scenario.
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|  *  When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() instead.
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|  *  Note that the result is only valid for a single invocation of LZ4F_compressUpdate().
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|  *  When invoking LZ4F_compressUpdate() multiple times,
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|  *  if the output buffer is gradually filled up instead of emptied and re-used from its start,
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|  *  one must check if there is enough remaining capacity before each invocation, using LZ4F_compressBound().
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|  * @return is always the same for a srcSize and prefsPtr.
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|  *  prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario.
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|  *  tech details :
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|  * @return if automatic flushing is not enabled, includes the possibility that internal buffer might already be filled by up to (blockSize-1) bytes.
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|  *  It also includes frame footer (ending + checksum), since it might be generated by LZ4F_compressEnd().
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|  * @return doesn't include frame header, as it was already generated by LZ4F_compressBegin().
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|  */
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| LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
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| 
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| /*! LZ4F_compressUpdate() :
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|  *  LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
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|  *  Important rule: dstCapacity MUST be large enough to ensure operation success even in worst case situations.
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|  *  This value is provided by LZ4F_compressBound().
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|  *  If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
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|  *  LZ4F_compressUpdate() doesn't guarantee error recovery.
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|  *  When an error occurs, compression context must be freed or resized.
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|  * `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
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|  * @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
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|  *           or an error code if it fails (which can be tested using LZ4F_isError())
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|  */
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| LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx,
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|                                        void* dstBuffer, size_t dstCapacity,
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|                                  const void* srcBuffer, size_t srcSize,
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|                                  const LZ4F_compressOptions_t* cOptPtr);
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| 
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| /*! LZ4F_flush() :
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|  *  When data must be generated and sent immediately, without waiting for a block to be completely filled,
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|  *  it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
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|  * `dstCapacity` must be large enough to ensure the operation will be successful.
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|  * `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default.
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|  * @return : nb of bytes written into dstBuffer (can be zero, when there is no data stored within cctx)
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|  *           or an error code if it fails (which can be tested using LZ4F_isError())
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|  *  Note : LZ4F_flush() is guaranteed to be successful when dstCapacity >= LZ4F_compressBound(0, prefsPtr).
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|  */
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| LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx,
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|                               void* dstBuffer, size_t dstCapacity,
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|                         const LZ4F_compressOptions_t* cOptPtr);
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| 
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| /*! LZ4F_compressEnd() :
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|  *  To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
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|  *  It will flush whatever data remained within `cctx` (like LZ4_flush())
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|  *  and properly finalize the frame, with an endMark and a checksum.
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|  * `cOptPtr` is optional : NULL can be provided, in which case all options will be set to default.
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|  * @return : nb of bytes written into dstBuffer, necessarily >= 4 (endMark),
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|  *           or an error code if it fails (which can be tested using LZ4F_isError())
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|  *  Note : LZ4F_compressEnd() is guaranteed to be successful when dstCapacity >= LZ4F_compressBound(0, prefsPtr).
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|  *  A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
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|  */
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| LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx,
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|                                     void* dstBuffer, size_t dstCapacity,
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|                               const LZ4F_compressOptions_t* cOptPtr);
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| 
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| 
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| /*-*********************************
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| *  Decompression functions
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| ***********************************/
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| typedef struct LZ4F_dctx_s LZ4F_dctx;   /* incomplete type */
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| typedef LZ4F_dctx* LZ4F_decompressionContext_t;   /* compatibility with previous API versions */
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| 
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| typedef struct {
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|   unsigned stableDst;    /* pledges that last 64KB decompressed data will remain available unmodified. This optimization skips storage operations in tmp buffers. */
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|   unsigned reserved[3];  /* must be set to zero for forward compatibility */
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| } LZ4F_decompressOptions_t;
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| 
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| 
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| /* Resource management */
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| 
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| /*! LZ4F_createDecompressionContext() :
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|  *  Create an LZ4F_dctx object, to track all decompression operations.
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|  *  The version provided MUST be LZ4F_VERSION.
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|  *  The function provides a pointer to an allocated and initialized LZ4F_dctx object.
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|  *  The result is an errorCode, which can be tested using LZ4F_isError().
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|  *  dctx memory can be released using LZ4F_freeDecompressionContext();
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|  *  Result of LZ4F_freeDecompressionContext() indicates current state of decompressionContext when being released.
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|  *  That is, it should be == 0 if decompression has been completed fully and correctly.
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|  */
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| LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
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| LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
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| 
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| 
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| /*-***********************************
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| *  Streaming decompression functions
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| *************************************/
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| 
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| #define LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH 5
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| 
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| /*! LZ4F_headerSize() : v1.9.0+
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|  *  Provide the header size of a frame starting at `src`.
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|  * `srcSize` must be >= LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH,
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|  *  which is enough to decode the header length.
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|  * @return : size of frame header
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|  *           or an error code, which can be tested using LZ4F_isError()
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|  *  note : Frame header size is variable, but is guaranteed to be
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|  *         >= LZ4F_HEADER_SIZE_MIN bytes, and <= LZ4F_HEADER_SIZE_MAX bytes.
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|  */
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| LZ4FLIB_API size_t LZ4F_headerSize(const void* src, size_t srcSize);
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| 
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| /*! LZ4F_getFrameInfo() :
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|  *  This function extracts frame parameters (max blockSize, dictID, etc.).
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|  *  Its usage is optional: user can call LZ4F_decompress() directly.
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|  *
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|  *  Extracted information will fill an existing LZ4F_frameInfo_t structure.
 | |
|  *  This can be useful for allocation and dictionary identification purposes.
 | |
|  *
 | |
|  *  LZ4F_getFrameInfo() can work in the following situations :
 | |
|  *
 | |
|  *  1) At the beginning of a new frame, before any invocation of LZ4F_decompress().
 | |
|  *     It will decode header from `srcBuffer`,
 | |
|  *     consuming the header and starting the decoding process.
 | |
|  *
 | |
|  *     Input size must be large enough to contain the full frame header.
 | |
|  *     Frame header size can be known beforehand by LZ4F_headerSize().
 | |
|  *     Frame header size is variable, but is guaranteed to be >= LZ4F_HEADER_SIZE_MIN bytes,
 | |
|  *     and not more than <= LZ4F_HEADER_SIZE_MAX bytes.
 | |
|  *     Hence, blindly providing LZ4F_HEADER_SIZE_MAX bytes or more will always work.
 | |
|  *     It's allowed to provide more input data than the header size,
 | |
|  *     LZ4F_getFrameInfo() will only consume the header.
 | |
|  *
 | |
|  *     If input size is not large enough,
 | |
|  *     aka if it's smaller than header size,
 | |
|  *     function will fail and return an error code.
 | |
|  *
 | |
|  *  2) After decoding has been started,
 | |
|  *     it's possible to invoke LZ4F_getFrameInfo() anytime
 | |
|  *     to extract already decoded frame parameters stored within dctx.
 | |
|  *
 | |
|  *     Note that, if decoding has barely started,
 | |
|  *     and not yet read enough information to decode the header,
 | |
|  *     LZ4F_getFrameInfo() will fail.
 | |
|  *
 | |
|  *  The number of bytes consumed from srcBuffer will be updated in *srcSizePtr (necessarily <= original value).
 | |
|  *  LZ4F_getFrameInfo() only consumes bytes when decoding has not yet started,
 | |
|  *  and when decoding the header has been successful.
 | |
|  *  Decompression must then resume from (srcBuffer + *srcSizePtr).
 | |
|  *
 | |
|  * @return : a hint about how many srcSize bytes LZ4F_decompress() expects for next call,
 | |
|  *           or an error code which can be tested using LZ4F_isError().
 | |
|  *  note 1 : in case of error, dctx is not modified. Decoding operation can resume from beginning safely.
 | |
|  *  note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure.
 | |
|  */
 | |
| LZ4FLIB_API size_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
 | |
|                                      LZ4F_frameInfo_t* frameInfoPtr,
 | |
|                                      const void* srcBuffer, size_t* srcSizePtr);
 | |
| 
 | |
| /*! LZ4F_decompress() :
 | |
|  *  Call this function repetitively to regenerate data compressed in `srcBuffer`.
 | |
|  *
 | |
|  *  The function requires a valid dctx state.
 | |
|  *  It will read up to *srcSizePtr bytes from srcBuffer,
 | |
|  *  and decompress data into dstBuffer, of capacity *dstSizePtr.
 | |
|  *
 | |
|  *  The nb of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
 | |
|  *  The nb of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
 | |
|  *
 | |
|  *  The function does not necessarily read all input bytes, so always check value in *srcSizePtr.
 | |
|  *  Unconsumed source data must be presented again in subsequent invocations.
 | |
|  *
 | |
|  * `dstBuffer` can freely change between each consecutive function invocation.
 | |
|  * `dstBuffer` content will be overwritten.
 | |
|  *
 | |
|  * @return : an hint of how many `srcSize` bytes LZ4F_decompress() expects for next call.
 | |
|  *  Schematically, it's the size of the current (or remaining) compressed block + header of next block.
 | |
|  *  Respecting the hint provides some small speed benefit, because it skips intermediate buffers.
 | |
|  *  This is just a hint though, it's always possible to provide any srcSize.
 | |
|  *
 | |
|  *  When a frame is fully decoded, @return will be 0 (no more data expected).
 | |
|  *  When provided with more bytes than necessary to decode a frame,
 | |
|  *  LZ4F_decompress() will stop reading exactly at end of current frame, and @return 0.
 | |
|  *
 | |
|  *  If decompression failed, @return is an error code, which can be tested using LZ4F_isError().
 | |
|  *  After a decompression error, the `dctx` context is not resumable.
 | |
|  *  Use LZ4F_resetDecompressionContext() to return to clean state.
 | |
|  *
 | |
|  *  After a frame is fully decoded, dctx can be used again to decompress another frame.
 | |
|  */
 | |
| LZ4FLIB_API size_t LZ4F_decompress(LZ4F_dctx* dctx,
 | |
|                                    void* dstBuffer, size_t* dstSizePtr,
 | |
|                                    const void* srcBuffer, size_t* srcSizePtr,
 | |
|                                    const LZ4F_decompressOptions_t* dOptPtr);
 | |
| 
 | |
| 
 | |
| /*! LZ4F_resetDecompressionContext() : added in v1.8.0
 | |
|  *  In case of an error, the context is left in "undefined" state.
 | |
|  *  In which case, it's necessary to reset it, before re-using it.
 | |
|  *  This method can also be used to abruptly stop any unfinished decompression,
 | |
|  *  and start a new one using same context resources. */
 | |
| LZ4FLIB_API void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx);   /* always successful */
 | |
| 
 | |
| 
 | |
| 
 | |
| #if defined (__cplusplus)
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #endif  /* LZ4F_H_09782039843 */
 | |
| 
 | |
| #if defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843)
 | |
| #define LZ4F_H_STATIC_09782039843
 | |
| 
 | |
| #if defined (__cplusplus)
 | |
| extern "C" {
 | |
| #endif
 | |
| 
 | |
| /* These declarations are not stable and may change in the future.
 | |
|  * They are therefore only safe to depend on
 | |
|  * when the caller is statically linked against the library.
 | |
|  * To access their declarations, define LZ4F_STATIC_LINKING_ONLY.
 | |
|  *
 | |
|  * By default, these symbols aren't published into shared/dynamic libraries.
 | |
|  * You can override this behavior and force them to be published
 | |
|  * by defining LZ4F_PUBLISH_STATIC_FUNCTIONS.
 | |
|  * Use at your own risk.
 | |
|  */
 | |
| #ifdef LZ4F_PUBLISH_STATIC_FUNCTIONS
 | |
| # define LZ4FLIB_STATIC_API LZ4FLIB_API
 | |
| #else
 | |
| # define LZ4FLIB_STATIC_API
 | |
| #endif
 | |
| 
 | |
| 
 | |
| /* ---   Error List   --- */
 | |
| #define LZ4F_LIST_ERRORS(ITEM) \
 | |
|         ITEM(OK_NoError) \
 | |
|         ITEM(ERROR_GENERIC) \
 | |
|         ITEM(ERROR_maxBlockSize_invalid) \
 | |
|         ITEM(ERROR_blockMode_invalid) \
 | |
|         ITEM(ERROR_contentChecksumFlag_invalid) \
 | |
|         ITEM(ERROR_compressionLevel_invalid) \
 | |
|         ITEM(ERROR_headerVersion_wrong) \
 | |
|         ITEM(ERROR_blockChecksum_invalid) \
 | |
|         ITEM(ERROR_reservedFlag_set) \
 | |
|         ITEM(ERROR_allocation_failed) \
 | |
|         ITEM(ERROR_srcSize_tooLarge) \
 | |
|         ITEM(ERROR_dstMaxSize_tooSmall) \
 | |
|         ITEM(ERROR_frameHeader_incomplete) \
 | |
|         ITEM(ERROR_frameType_unknown) \
 | |
|         ITEM(ERROR_frameSize_wrong) \
 | |
|         ITEM(ERROR_srcPtr_wrong) \
 | |
|         ITEM(ERROR_decompressionFailed) \
 | |
|         ITEM(ERROR_headerChecksum_invalid) \
 | |
|         ITEM(ERROR_contentChecksum_invalid) \
 | |
|         ITEM(ERROR_frameDecoding_alreadyStarted) \
 | |
|         ITEM(ERROR_maxCode)
 | |
| 
 | |
| #define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM,
 | |
| 
 | |
| /* enum list is exposed, to handle specific errors */
 | |
| typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM)
 | |
|               _LZ4F_dummy_error_enum_for_c89_never_used } LZ4F_errorCodes;
 | |
| 
 | |
| LZ4FLIB_STATIC_API LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult);
 | |
| 
 | |
| LZ4FLIB_STATIC_API size_t LZ4F_getBlockSize(unsigned);
 | |
| 
 | |
| /**********************************
 | |
|  *  Bulk processing dictionary API
 | |
|  *********************************/
 | |
| 
 | |
| /* A Dictionary is useful for the compression of small messages (KB range).
 | |
|  * It dramatically improves compression efficiency.
 | |
|  *
 | |
|  * LZ4 can ingest any input as dictionary, though only the last 64 KB are useful.
 | |
|  * Best results are generally achieved by using Zstandard's Dictionary Builder
 | |
|  * to generate a high-quality dictionary from a set of samples.
 | |
|  *
 | |
|  * Loading a dictionary has a cost, since it involves construction of tables.
 | |
|  * The Bulk processing dictionary API makes it possible to share this cost
 | |
|  * over an arbitrary number of compression jobs, even concurrently,
 | |
|  * markedly improving compression latency for these cases.
 | |
|  *
 | |
|  * The same dictionary will have to be used on the decompression side
 | |
|  * for decoding to be successful.
 | |
|  * To help identify the correct dictionary at decoding stage,
 | |
|  * the frame header allows optional embedding of a dictID field.
 | |
|  */
 | |
| typedef struct LZ4F_CDict_s LZ4F_CDict;
 | |
| 
 | |
| /*! LZ4_createCDict() :
 | |
|  *  When compressing multiple messages / blocks using the same dictionary, it's recommended to load it just once.
 | |
|  *  LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
 | |
|  *  LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
 | |
|  * `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */
 | |
| LZ4FLIB_STATIC_API LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
 | |
| LZ4FLIB_STATIC_API void        LZ4F_freeCDict(LZ4F_CDict* CDict);
 | |
| 
 | |
| 
 | |
| /*! LZ4_compressFrame_usingCDict() :
 | |
|  *  Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
 | |
|  *  cctx must point to a context created by LZ4F_createCompressionContext().
 | |
|  *  If cdict==NULL, compress without a dictionary.
 | |
|  *  dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
 | |
|  *  If this condition is not respected, function will fail (@return an errorCode).
 | |
|  *  The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
 | |
|  *  but it's not recommended, as it's the only way to provide dictID in the frame header.
 | |
|  * @return : number of bytes written into dstBuffer.
 | |
|  *           or an error code if it fails (can be tested using LZ4F_isError()) */
 | |
| LZ4FLIB_STATIC_API size_t LZ4F_compressFrame_usingCDict(
 | |
|     LZ4F_cctx* cctx,
 | |
|     void* dst, size_t dstCapacity,
 | |
|     const void* src, size_t srcSize,
 | |
|     const LZ4F_CDict* cdict,
 | |
|     const LZ4F_preferences_t* preferencesPtr);
 | |
| 
 | |
| 
 | |
| /*! LZ4F_compressBegin_usingCDict() :
 | |
|  *  Inits streaming dictionary compression, and writes the frame header into dstBuffer.
 | |
|  *  dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
 | |
|  * `prefsPtr` is optional : you may provide NULL as argument,
 | |
|  *  however, it's the only way to provide dictID in the frame header.
 | |
|  * @return : number of bytes written into dstBuffer for the header,
 | |
|  *           or an error code (which can be tested using LZ4F_isError()) */
 | |
| LZ4FLIB_STATIC_API size_t LZ4F_compressBegin_usingCDict(
 | |
|     LZ4F_cctx* cctx,
 | |
|     void* dstBuffer, size_t dstCapacity,
 | |
|     const LZ4F_CDict* cdict,
 | |
|     const LZ4F_preferences_t* prefsPtr);
 | |
| 
 | |
| 
 | |
| /*! LZ4F_decompress_usingDict() :
 | |
|  *  Same as LZ4F_decompress(), using a predefined dictionary.
 | |
|  *  Dictionary is used "in place", without any preprocessing.
 | |
|  *  It must remain accessible throughout the entire frame decoding. */
 | |
| LZ4FLIB_STATIC_API size_t LZ4F_decompress_usingDict(
 | |
|     LZ4F_dctx* dctxPtr,
 | |
|     void* dstBuffer, size_t* dstSizePtr,
 | |
|     const void* srcBuffer, size_t* srcSizePtr,
 | |
|     const void* dict, size_t dictSize,
 | |
|     const LZ4F_decompressOptions_t* decompressOptionsPtr);
 | |
| 
 | |
| #if defined (__cplusplus)
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #endif  /* defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843) */
 |