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- /*
- * LZ4 - Fast LZ compression algorithm
- * Header File
- * Copyright (C) 2011-2020, Yann Collet.
- BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are
- met:
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above
- copyright notice, this list of conditions and the following disclaimer
- in the documentation and/or other materials provided with the
- distribution.
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- You can contact the author at :
- - LZ4 homepage : http://www.lz4.org
- - LZ4 source repository : https://github.com/lz4/lz4
- */
- #if defined (__cplusplus)
- extern "C" {
- #endif
- #ifndef LZ4_H_2983827168210
- #define LZ4_H_2983827168210
- /* --- Dependency --- */
- #include <stddef.h> /* size_t */
- /**
- Introduction
- LZ4 is lossless compression algorithm, providing compression speed >500 MB/s per core,
- scalable with multi-cores CPU. It features an extremely fast decoder, with speed in
- multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.
- The LZ4 compression library provides in-memory compression and decompression functions.
- It gives full buffer control to user.
- Compression can be done in:
- - a single step (described as Simple Functions)
- - a single step, reusing a context (described in Advanced Functions)
- - unbounded multiple steps (described as Streaming compression)
- lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md).
- Decompressing such a compressed block requires additional metadata.
- Exact metadata depends on exact decompression function.
- For the typical case of LZ4_decompress_safe(),
- metadata includes block's compressed size, and maximum bound of decompressed size.
- Each application is free to encode and pass such metadata in whichever way it wants.
- lz4.h only handle blocks, it can not generate Frames.
- Blocks are different from Frames (doc/lz4_Frame_format.md).
- Frames bundle both blocks and metadata in a specified manner.
- Embedding metadata is required for compressed data to be self-contained and portable.
- Frame format is delivered through a companion API, declared in lz4frame.h.
- The `lz4` CLI can only manage frames.
- */
- /*^***************************************************************
- * Export parameters
- *****************************************************************/
- /*
- * LZ4_DLL_EXPORT :
- * Enable exporting of functions when building a Windows DLL
- * LZ4LIB_VISIBILITY :
- * Control library symbols visibility.
- */
- #ifndef LZ4LIB_VISIBILITY
- # if defined(__GNUC__) && (__GNUC__ >= 4)
- # define LZ4LIB_VISIBILITY __attribute__ ((visibility ("default")))
- # else
- # define LZ4LIB_VISIBILITY
- # endif
- #endif
- #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
- # define LZ4LIB_API __declspec(dllexport) LZ4LIB_VISIBILITY
- #elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
- # define LZ4LIB_API __declspec(dllimport) LZ4LIB_VISIBILITY /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
- #else
- # define LZ4LIB_API LZ4LIB_VISIBILITY
- #endif
- /*! LZ4_FREESTANDING :
- * When this macro is set to 1, it enables "freestanding mode" that is
- * suitable for typical freestanding environment which doesn't support
- * standard C library.
- *
- * - LZ4_FREESTANDING is a compile-time switch.
- * - It requires the following macros to be defined:
- * LZ4_memcpy, LZ4_memmove, LZ4_memset.
- * - It only enables LZ4/HC functions which don't use heap.
- * All LZ4F_* functions are not supported.
- * - See tests/freestanding.c to check its basic setup.
- */
- #if defined(LZ4_FREESTANDING) && (LZ4_FREESTANDING == 1)
- # define LZ4_HEAPMODE 0
- # define LZ4HC_HEAPMODE 0
- # define LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION 1
- # if !defined(LZ4_memcpy)
- # error "LZ4_FREESTANDING requires macro 'LZ4_memcpy'."
- # endif
- # if !defined(LZ4_memset)
- # error "LZ4_FREESTANDING requires macro 'LZ4_memset'."
- # endif
- # if !defined(LZ4_memmove)
- # error "LZ4_FREESTANDING requires macro 'LZ4_memmove'."
- # endif
- #elif ! defined(LZ4_FREESTANDING)
- # define LZ4_FREESTANDING 0
- #endif
- /*------ Version ------*/
- #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
- #define LZ4_VERSION_MINOR 9 /* for new (non-breaking) interface capabilities */
- #define LZ4_VERSION_RELEASE 4 /* for tweaks, bug-fixes, or development */
- #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
- #define LZ4_LIB_VERSION LZ4_VERSION_MAJOR.LZ4_VERSION_MINOR.LZ4_VERSION_RELEASE
- #define LZ4_QUOTE(str) #str
- #define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str)
- #define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION) /* requires v1.7.3+ */
- LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version; requires v1.3.0+ */
- LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; useful to check dll version; requires v1.7.5+ */
- /*-************************************
- * Tuning parameter
- **************************************/
- #define LZ4_MEMORY_USAGE_MIN 10
- #define LZ4_MEMORY_USAGE_DEFAULT 14
- #define LZ4_MEMORY_USAGE_MAX 20
- /*!
- * LZ4_MEMORY_USAGE :
- * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; )
- * Increasing memory usage improves compression ratio, at the cost of speed.
- * Reduced memory usage may improve speed at the cost of ratio, thanks to better cache locality.
- * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
- */
- #ifndef LZ4_MEMORY_USAGE
- # define LZ4_MEMORY_USAGE LZ4_MEMORY_USAGE_DEFAULT
- #endif
- #if (LZ4_MEMORY_USAGE < LZ4_MEMORY_USAGE_MIN)
- # error "LZ4_MEMORY_USAGE is too small !"
- #endif
- #if (LZ4_MEMORY_USAGE > LZ4_MEMORY_USAGE_MAX)
- # error "LZ4_MEMORY_USAGE is too large !"
- #endif
- /*-************************************
- * Simple Functions
- **************************************/
- /*! LZ4_compress_default() :
- * Compresses 'srcSize' bytes from buffer 'src'
- * into already allocated 'dst' buffer of size 'dstCapacity'.
- * Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize).
- * It also runs faster, so it's a recommended setting.
- * If the function cannot compress 'src' into a more limited 'dst' budget,
- * compression stops *immediately*, and the function result is zero.
- * In which case, 'dst' content is undefined (invalid).
- * srcSize : max supported value is LZ4_MAX_INPUT_SIZE.
- * dstCapacity : size of buffer 'dst' (which must be already allocated)
- * @return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity)
- * or 0 if compression fails
- * Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer).
- */
- LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity);
- /*! LZ4_decompress_safe() :
- * compressedSize : is the exact complete size of the compressed block.
- * dstCapacity : is the size of destination buffer (which must be already allocated), presumed an upper bound of decompressed size.
- * @return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity)
- * If destination buffer is not large enough, decoding will stop and output an error code (negative value).
- * If the source stream is detected malformed, the function will stop decoding and return a negative result.
- * Note 1 : This function is protected against malicious data packets :
- * it will never writes outside 'dst' buffer, nor read outside 'source' buffer,
- * even if the compressed block is maliciously modified to order the decoder to do these actions.
- * In such case, the decoder stops immediately, and considers the compressed block malformed.
- * Note 2 : compressedSize and dstCapacity must be provided to the function, the compressed block does not contain them.
- * The implementation is free to send / store / derive this information in whichever way is most beneficial.
- * If there is a need for a different format which bundles together both compressed data and its metadata, consider looking at lz4frame.h instead.
- */
- LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity);
- /*-************************************
- * Advanced Functions
- **************************************/
- #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
- #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
- /*! LZ4_compressBound() :
- Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
- This function is primarily useful for memory allocation purposes (destination buffer size).
- Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
- Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize)
- inputSize : max supported value is LZ4_MAX_INPUT_SIZE
- return : maximum output size in a "worst case" scenario
- or 0, if input size is incorrect (too large or negative)
- */
- LZ4LIB_API int LZ4_compressBound(int inputSize);
- /*! LZ4_compress_fast() :
- Same as LZ4_compress_default(), but allows selection of "acceleration" factor.
- The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
- It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
- An acceleration value of "1" is the same as regular LZ4_compress_default()
- Values <= 0 will be replaced by LZ4_ACCELERATION_DEFAULT (currently == 1, see lz4.c).
- Values > LZ4_ACCELERATION_MAX will be replaced by LZ4_ACCELERATION_MAX (currently == 65537, see lz4.c).
- */
- LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
- /*! LZ4_compress_fast_extState() :
- * Same as LZ4_compress_fast(), using an externally allocated memory space for its state.
- * Use LZ4_sizeofState() to know how much memory must be allocated,
- * and allocate it on 8-bytes boundaries (using `malloc()` typically).
- * Then, provide this buffer as `void* state` to compression function.
- */
- LZ4LIB_API int LZ4_sizeofState(void);
- LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
- /*! LZ4_compress_destSize() :
- * Reverse the logic : compresses as much data as possible from 'src' buffer
- * into already allocated buffer 'dst', of size >= 'targetDestSize'.
- * This function either compresses the entire 'src' content into 'dst' if it's large enough,
- * or fill 'dst' buffer completely with as much data as possible from 'src'.
- * note: acceleration parameter is fixed to "default".
- *
- * *srcSizePtr : will be modified to indicate how many bytes where read from 'src' to fill 'dst'.
- * New value is necessarily <= input value.
- * @return : Nb bytes written into 'dst' (necessarily <= targetDestSize)
- * or 0 if compression fails.
- *
- * Note : from v1.8.2 to v1.9.1, this function had a bug (fixed un v1.9.2+):
- * the produced compressed content could, in specific circumstances,
- * require to be decompressed into a destination buffer larger
- * by at least 1 byte than the content to decompress.
- * If an application uses `LZ4_compress_destSize()`,
- * it's highly recommended to update liblz4 to v1.9.2 or better.
- * If this can't be done or ensured,
- * the receiving decompression function should provide
- * a dstCapacity which is > decompressedSize, by at least 1 byte.
- * See https://github.com/lz4/lz4/issues/859 for details
- */
- LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize);
- /*! LZ4_decompress_safe_partial() :
- * Decompress an LZ4 compressed block, of size 'srcSize' at position 'src',
- * into destination buffer 'dst' of size 'dstCapacity'.
- * Up to 'targetOutputSize' bytes will be decoded.
- * The function stops decoding on reaching this objective.
- * This can be useful to boost performance
- * whenever only the beginning of a block is required.
- *
- * @return : the number of bytes decoded in `dst` (necessarily <= targetOutputSize)
- * If source stream is detected malformed, function returns a negative result.
- *
- * Note 1 : @return can be < targetOutputSize, if compressed block contains less data.
- *
- * Note 2 : targetOutputSize must be <= dstCapacity
- *
- * Note 3 : this function effectively stops decoding on reaching targetOutputSize,
- * so dstCapacity is kind of redundant.
- * This is because in older versions of this function,
- * decoding operation would still write complete sequences.
- * Therefore, there was no guarantee that it would stop writing at exactly targetOutputSize,
- * it could write more bytes, though only up to dstCapacity.
- * Some "margin" used to be required for this operation to work properly.
- * Thankfully, this is no longer necessary.
- * The function nonetheless keeps the same signature, in an effort to preserve API compatibility.
- *
- * Note 4 : If srcSize is the exact size of the block,
- * then targetOutputSize can be any value,
- * including larger than the block's decompressed size.
- * The function will, at most, generate block's decompressed size.
- *
- * Note 5 : If srcSize is _larger_ than block's compressed size,
- * then targetOutputSize **MUST** be <= block's decompressed size.
- * Otherwise, *silent corruption will occur*.
- */
- LZ4LIB_API int LZ4_decompress_safe_partial (const char* src, char* dst, int srcSize, int targetOutputSize, int dstCapacity);
- /*-*********************************************
- * Streaming Compression Functions
- ***********************************************/
- typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */
- /**
- Note about RC_INVOKED
- - RC_INVOKED is predefined symbol of rc.exe (the resource compiler which is part of MSVC/Visual Studio).
- https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros
- - Since rc.exe is a legacy compiler, it truncates long symbol (> 30 chars)
- and reports warning "RC4011: identifier truncated".
- - To eliminate the warning, we surround long preprocessor symbol with
- "#if !defined(RC_INVOKED) ... #endif" block that means
- "skip this block when rc.exe is trying to read it".
- */
- #if !defined(RC_INVOKED) /* https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros */
- #if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION)
- LZ4LIB_API LZ4_stream_t* LZ4_createStream(void);
- LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr);
- #endif /* !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) */
- #endif
- /*! LZ4_resetStream_fast() : v1.9.0+
- * Use this to prepare an LZ4_stream_t for a new chain of dependent blocks
- * (e.g., LZ4_compress_fast_continue()).
- *
- * An LZ4_stream_t must be initialized once before usage.
- * This is automatically done when created by LZ4_createStream().
- * However, should the LZ4_stream_t be simply declared on stack (for example),
- * it's necessary to initialize it first, using LZ4_initStream().
- *
- * After init, start any new stream with LZ4_resetStream_fast().
- * A same LZ4_stream_t can be re-used multiple times consecutively
- * and compress multiple streams,
- * provided that it starts each new stream with LZ4_resetStream_fast().
- *
- * LZ4_resetStream_fast() is much faster than LZ4_initStream(),
- * but is not compatible with memory regions containing garbage data.
- *
- * Note: it's only useful to call LZ4_resetStream_fast()
- * in the context of streaming compression.
- * The *extState* functions perform their own resets.
- * Invoking LZ4_resetStream_fast() before is redundant, and even counterproductive.
- */
- LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr);
- /*! LZ4_loadDict() :
- * Use this function to reference a static dictionary into LZ4_stream_t.
- * The dictionary must remain available during compression.
- * LZ4_loadDict() triggers a reset, so any previous data will be forgotten.
- * The same dictionary will have to be loaded on decompression side for successful decoding.
- * Dictionary are useful for better compression of small data (KB range).
- * While LZ4 accept any input as dictionary,
- * results are generally better when using Zstandard's Dictionary Builder.
- * Loading a size of 0 is allowed, and is the same as reset.
- * @return : loaded dictionary size, in bytes (necessarily <= 64 KB)
- */
- LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
- /*! LZ4_compress_fast_continue() :
- * Compress 'src' content using data from previously compressed blocks, for better compression ratio.
- * 'dst' buffer must be already allocated.
- * If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
- *
- * @return : size of compressed block
- * or 0 if there is an error (typically, cannot fit into 'dst').
- *
- * Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block.
- * Each block has precise boundaries.
- * Each block must be decompressed separately, calling LZ4_decompress_*() with relevant metadata.
- * It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together.
- *
- * Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory !
- *
- * Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB.
- * Make sure that buffers are separated, by at least one byte.
- * This construction ensures that each block only depends on previous block.
- *
- * Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.
- *
- * Note 5 : After an error, the stream status is undefined (invalid), it can only be reset or freed.
- */
- LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
- /*! LZ4_saveDict() :
- * If last 64KB data cannot be guaranteed to remain available at its current memory location,
- * save it into a safer place (char* safeBuffer).
- * This is schematically equivalent to a memcpy() followed by LZ4_loadDict(),
- * but is much faster, because LZ4_saveDict() doesn't need to rebuild tables.
- * @return : saved dictionary size in bytes (necessarily <= maxDictSize), or 0 if error.
- */
- LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int maxDictSize);
- /*-**********************************************
- * Streaming Decompression Functions
- * Bufferless synchronous API
- ************************************************/
- typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* tracking context */
- /*! LZ4_createStreamDecode() and LZ4_freeStreamDecode() :
- * creation / destruction of streaming decompression tracking context.
- * A tracking context can be re-used multiple times.
- */
- #if !defined(RC_INVOKED) /* https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros */
- #if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION)
- LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void);
- LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
- #endif /* !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) */
- #endif
- /*! LZ4_setStreamDecode() :
- * An LZ4_streamDecode_t context can be allocated once and re-used multiple times.
- * Use this function to start decompression of a new stream of blocks.
- * A dictionary can optionally be set. Use NULL or size 0 for a reset order.
- * Dictionary is presumed stable : it must remain accessible and unmodified during next decompression.
- * @return : 1 if OK, 0 if error
- */
- LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
- /*! LZ4_decoderRingBufferSize() : v1.8.2+
- * Note : in a ring buffer scenario (optional),
- * blocks are presumed decompressed next to each other
- * up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize),
- * at which stage it resumes from beginning of ring buffer.
- * When setting such a ring buffer for streaming decompression,
- * provides the minimum size of this ring buffer
- * to be compatible with any source respecting maxBlockSize condition.
- * @return : minimum ring buffer size,
- * or 0 if there is an error (invalid maxBlockSize).
- */
- LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize);
- #define LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize) (65536 + 14 + (maxBlockSize)) /* for static allocation; maxBlockSize presumed valid */
- /*! LZ4_decompress_*_continue() :
- * These decoding functions allow decompression of consecutive blocks in "streaming" mode.
- * A block is an unsplittable entity, it must be presented entirely to a decompression function.
- * Decompression functions only accepts one block at a time.
- * The last 64KB of previously decoded data *must* remain available and unmodified at the memory position where they were decoded.
- * If less than 64KB of data has been decoded, all the data must be present.
- *
- * Special : if decompression side sets a ring buffer, it must respect one of the following conditions :
- * - Decompression buffer size is _at least_ LZ4_decoderRingBufferSize(maxBlockSize).
- * maxBlockSize is the maximum size of any single block. It can have any value > 16 bytes.
- * In which case, encoding and decoding buffers do not need to be synchronized.
- * Actually, data can be produced by any source compliant with LZ4 format specification, and respecting maxBlockSize.
- * - Synchronized mode :
- * Decompression buffer size is _exactly_ the same as compression buffer size,
- * and follows exactly same update rule (block boundaries at same positions),
- * and decoding function is provided with exact decompressed size of each block (exception for last block of the stream),
- * _then_ decoding & encoding ring buffer can have any size, including small ones ( < 64 KB).
- * - Decompression buffer is larger than encoding buffer, by a minimum of maxBlockSize more bytes.
- * In which case, encoding and decoding buffers do not need to be synchronized,
- * and encoding ring buffer can have any size, including small ones ( < 64 KB).
- *
- * Whenever these conditions are not possible,
- * save the last 64KB of decoded data into a safe buffer where it can't be modified during decompression,
- * then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block.
- */
- LZ4LIB_API int
- LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode,
- const char* src, char* dst,
- int srcSize, int dstCapacity);
- /*! LZ4_decompress_*_usingDict() :
- * These decoding functions work the same as
- * a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue()
- * They are stand-alone, and don't need an LZ4_streamDecode_t structure.
- * Dictionary is presumed stable : it must remain accessible and unmodified during decompression.
- * Performance tip : Decompression speed can be substantially increased
- * when dst == dictStart + dictSize.
- */
- LZ4LIB_API int
- LZ4_decompress_safe_usingDict(const char* src, char* dst,
- int srcSize, int dstCapacity,
- const char* dictStart, int dictSize);
- LZ4LIB_API int
- LZ4_decompress_safe_partial_usingDict(const char* src, char* dst,
- int compressedSize,
- int targetOutputSize, int maxOutputSize,
- const char* dictStart, int dictSize);
- #endif /* LZ4_H_2983827168210 */
- /*^*************************************
- * !!!!!! STATIC LINKING ONLY !!!!!!
- ***************************************/
- /*-****************************************************************************
- * Experimental section
- *
- * Symbols declared in this section must be considered unstable. Their
- * signatures or semantics may change, or they may be removed altogether in the
- * future. They are therefore only safe to depend on when the caller is
- * statically linked against the library.
- *
- * To protect against unsafe usage, not only are the declarations guarded,
- * the definitions are hidden by default
- * when building LZ4 as a shared/dynamic library.
- *
- * In order to access these declarations,
- * define LZ4_STATIC_LINKING_ONLY in your application
- * before including LZ4's headers.
- *
- * In order to make their implementations accessible dynamically, you must
- * define LZ4_PUBLISH_STATIC_FUNCTIONS when building the LZ4 library.
- ******************************************************************************/
- #ifdef LZ4_STATIC_LINKING_ONLY
- #ifndef LZ4_STATIC_3504398509
- #define LZ4_STATIC_3504398509
- #ifdef LZ4_PUBLISH_STATIC_FUNCTIONS
- #define LZ4LIB_STATIC_API LZ4LIB_API
- #else
- #define LZ4LIB_STATIC_API
- #endif
- /*! LZ4_compress_fast_extState_fastReset() :
- * A variant of LZ4_compress_fast_extState().
- *
- * Using this variant avoids an expensive initialization step.
- * It is only safe to call if the state buffer is known to be correctly initialized already
- * (see above comment on LZ4_resetStream_fast() for a definition of "correctly initialized").
- * From a high level, the difference is that
- * this function initializes the provided state with a call to something like LZ4_resetStream_fast()
- * while LZ4_compress_fast_extState() starts with a call to LZ4_resetStream().
- */
- LZ4LIB_STATIC_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
- /*! LZ4_attach_dictionary() :
- * This is an experimental API that allows
- * efficient use of a static dictionary many times.
- *
- * Rather than re-loading the dictionary buffer into a working context before
- * each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a
- * working LZ4_stream_t, this function introduces a no-copy setup mechanism,
- * in which the working stream references the dictionary stream in-place.
- *
- * Several assumptions are made about the state of the dictionary stream.
- * Currently, only streams which have been prepared by LZ4_loadDict() should
- * be expected to work.
- *
- * Alternatively, the provided dictionaryStream may be NULL,
- * in which case any existing dictionary stream is unset.
- *
- * If a dictionary is provided, it replaces any pre-existing stream history.
- * The dictionary contents are the only history that can be referenced and
- * logically immediately precede the data compressed in the first subsequent
- * compression call.
- *
- * The dictionary will only remain attached to the working stream through the
- * first compression call, at the end of which it is cleared. The dictionary
- * stream (and source buffer) must remain in-place / accessible / unchanged
- * through the completion of the first compression call on the stream.
- */
- LZ4LIB_STATIC_API void
- LZ4_attach_dictionary(LZ4_stream_t* workingStream,
- const LZ4_stream_t* dictionaryStream);
- /*! In-place compression and decompression
- *
- * It's possible to have input and output sharing the same buffer,
- * for highly constrained memory environments.
- * In both cases, it requires input to lay at the end of the buffer,
- * and decompression to start at beginning of the buffer.
- * Buffer size must feature some margin, hence be larger than final size.
- *
- * |<------------------------buffer--------------------------------->|
- * |<-----------compressed data--------->|
- * |<-----------decompressed size------------------>|
- * |<----margin---->|
- *
- * This technique is more useful for decompression,
- * since decompressed size is typically larger,
- * and margin is short.
- *
- * In-place decompression will work inside any buffer
- * which size is >= LZ4_DECOMPRESS_INPLACE_BUFFER_SIZE(decompressedSize).
- * This presumes that decompressedSize > compressedSize.
- * Otherwise, it means compression actually expanded data,
- * and it would be more efficient to store such data with a flag indicating it's not compressed.
- * This can happen when data is not compressible (already compressed, or encrypted).
- *
- * For in-place compression, margin is larger, as it must be able to cope with both
- * history preservation, requiring input data to remain unmodified up to LZ4_DISTANCE_MAX,
- * and data expansion, which can happen when input is not compressible.
- * As a consequence, buffer size requirements are much higher,
- * and memory savings offered by in-place compression are more limited.
- *
- * There are ways to limit this cost for compression :
- * - Reduce history size, by modifying LZ4_DISTANCE_MAX.
- * Note that it is a compile-time constant, so all compressions will apply this limit.
- * Lower values will reduce compression ratio, except when input_size < LZ4_DISTANCE_MAX,
- * so it's a reasonable trick when inputs are known to be small.
- * - Require the compressor to deliver a "maximum compressed size".
- * This is the `dstCapacity` parameter in `LZ4_compress*()`.
- * When this size is < LZ4_COMPRESSBOUND(inputSize), then compression can fail,
- * in which case, the return code will be 0 (zero).
- * The caller must be ready for these cases to happen,
- * and typically design a backup scheme to send data uncompressed.
- * The combination of both techniques can significantly reduce
- * the amount of margin required for in-place compression.
- *
- * In-place compression can work in any buffer
- * which size is >= (maxCompressedSize)
- * with maxCompressedSize == LZ4_COMPRESSBOUND(srcSize) for guaranteed compression success.
- * LZ4_COMPRESS_INPLACE_BUFFER_SIZE() depends on both maxCompressedSize and LZ4_DISTANCE_MAX,
- * so it's possible to reduce memory requirements by playing with them.
- */
- #define LZ4_DECOMPRESS_INPLACE_MARGIN(compressedSize) (((compressedSize) >> 8) + 32)
- #define LZ4_DECOMPRESS_INPLACE_BUFFER_SIZE(decompressedSize) ((decompressedSize) + LZ4_DECOMPRESS_INPLACE_MARGIN(decompressedSize)) /**< note: presumes that compressedSize < decompressedSize. note2: margin is overestimated a bit, since it could use compressedSize instead */
- #ifndef LZ4_DISTANCE_MAX /* history window size; can be user-defined at compile time */
- # define LZ4_DISTANCE_MAX 65535 /* set to maximum value by default */
- #endif
- #define LZ4_COMPRESS_INPLACE_MARGIN (LZ4_DISTANCE_MAX + 32) /* LZ4_DISTANCE_MAX can be safely replaced by srcSize when it's smaller */
- #define LZ4_COMPRESS_INPLACE_BUFFER_SIZE(maxCompressedSize) ((maxCompressedSize) + LZ4_COMPRESS_INPLACE_MARGIN) /**< maxCompressedSize is generally LZ4_COMPRESSBOUND(inputSize), but can be set to any lower value, with the risk that compression can fail (return code 0(zero)) */
- #endif /* LZ4_STATIC_3504398509 */
- #endif /* LZ4_STATIC_LINKING_ONLY */
- #ifndef LZ4_H_98237428734687
- #define LZ4_H_98237428734687
- /*-************************************************************
- * Private Definitions
- **************************************************************
- * Do not use these definitions directly.
- * They are only exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`.
- * Accessing members will expose user code to API and/or ABI break in future versions of the library.
- **************************************************************/
- #define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2)
- #define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
- #define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */
- #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
- # include <stdint.h>
- typedef int8_t LZ4_i8;
- typedef uint8_t LZ4_byte;
- typedef uint16_t LZ4_u16;
- typedef uint32_t LZ4_u32;
- #else
- typedef signed char LZ4_i8;
- typedef unsigned char LZ4_byte;
- typedef unsigned short LZ4_u16;
- typedef unsigned int LZ4_u32;
- #endif
- /*! LZ4_stream_t :
- * Never ever use below internal definitions directly !
- * These definitions are not API/ABI safe, and may change in future versions.
- * If you need static allocation, declare or allocate an LZ4_stream_t object.
- **/
- typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
- struct LZ4_stream_t_internal {
- LZ4_u32 hashTable[LZ4_HASH_SIZE_U32];
- const LZ4_byte* dictionary;
- const LZ4_stream_t_internal* dictCtx;
- LZ4_u32 currentOffset;
- LZ4_u32 tableType;
- LZ4_u32 dictSize;
- /* Implicit padding to ensure structure is aligned */
- };
- #define LZ4_STREAM_MINSIZE ((1UL << LZ4_MEMORY_USAGE) + 32) /* static size, for inter-version compatibility */
- union LZ4_stream_u {
- char minStateSize[LZ4_STREAM_MINSIZE];
- LZ4_stream_t_internal internal_donotuse;
- }; /* previously typedef'd to LZ4_stream_t */
- /*! LZ4_initStream() : v1.9.0+
- * An LZ4_stream_t structure must be initialized at least once.
- * This is automatically done when invoking LZ4_createStream(),
- * but it's not when the structure is simply declared on stack (for example).
- *
- * Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t.
- * It can also initialize any arbitrary buffer of sufficient size,
- * and will @return a pointer of proper type upon initialization.
- *
- * Note : initialization fails if size and alignment conditions are not respected.
- * In which case, the function will @return NULL.
- * Note2: An LZ4_stream_t structure guarantees correct alignment and size.
- * Note3: Before v1.9.0, use LZ4_resetStream() instead
- **/
- LZ4LIB_API LZ4_stream_t* LZ4_initStream (void* buffer, size_t size);
- /*! LZ4_streamDecode_t :
- * Never ever use below internal definitions directly !
- * These definitions are not API/ABI safe, and may change in future versions.
- * If you need static allocation, declare or allocate an LZ4_streamDecode_t object.
- **/
- typedef struct {
- const LZ4_byte* externalDict;
- const LZ4_byte* prefixEnd;
- size_t extDictSize;
- size_t prefixSize;
- } LZ4_streamDecode_t_internal;
- #define LZ4_STREAMDECODE_MINSIZE 32
- union LZ4_streamDecode_u {
- char minStateSize[LZ4_STREAMDECODE_MINSIZE];
- LZ4_streamDecode_t_internal internal_donotuse;
- } ; /* previously typedef'd to LZ4_streamDecode_t */
- /*-************************************
- * Obsolete Functions
- **************************************/
- /*! Deprecation warnings
- *
- * Deprecated functions make the compiler generate a warning when invoked.
- * This is meant to invite users to update their source code.
- * Should deprecation warnings be a problem, it is generally possible to disable them,
- * typically with -Wno-deprecated-declarations for gcc
- * or _CRT_SECURE_NO_WARNINGS in Visual.
- *
- * Another method is to define LZ4_DISABLE_DEPRECATE_WARNINGS
- * before including the header file.
- */
- #ifdef LZ4_DISABLE_DEPRECATE_WARNINGS
- # define LZ4_DEPRECATED(message) /* disable deprecation warnings */
- #else
- # if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
- # define LZ4_DEPRECATED(message) [[deprecated(message)]]
- # elif defined(_MSC_VER)
- # define LZ4_DEPRECATED(message) __declspec(deprecated(message))
- # elif defined(__clang__) || (defined(__GNUC__) && (__GNUC__ * 10 + __GNUC_MINOR__ >= 45))
- # define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
- # elif defined(__GNUC__) && (__GNUC__ * 10 + __GNUC_MINOR__ >= 31)
- # define LZ4_DEPRECATED(message) __attribute__((deprecated))
- # else
- # pragma message("WARNING: LZ4_DEPRECATED needs custom implementation for this compiler")
- # define LZ4_DEPRECATED(message) /* disabled */
- # endif
- #endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */
- /*! Obsolete compression functions (since v1.7.3) */
- LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* src, char* dest, int srcSize);
- LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* src, char* dest, int srcSize, int maxOutputSize);
- LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
- LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
- LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
- LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
- /*! Obsolete decompression functions (since v1.8.0) */
- LZ4_DEPRECATED("use LZ4_decompress_fast() instead") LZ4LIB_API int LZ4_uncompress (const char* source, char* dest, int outputSize);
- LZ4_DEPRECATED("use LZ4_decompress_safe() instead") LZ4LIB_API int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);
- /* Obsolete streaming functions (since v1.7.0)
- * degraded functionality; do not use!
- *
- * In order to perform streaming compression, these functions depended on data
- * that is no longer tracked in the state. They have been preserved as well as
- * possible: using them will still produce a correct output. However, they don't
- * actually retain any history between compression calls. The compression ratio
- * achieved will therefore be no better than compressing each chunk
- * independently.
- */
- LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API void* LZ4_create (char* inputBuffer);
- LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API int LZ4_sizeofStreamState(void);
- LZ4_DEPRECATED("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void* state, char* inputBuffer);
- LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInputBuffer (void* state);
- /*! Obsolete streaming decoding functions (since v1.7.0) */
- LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
- LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
- /*! Obsolete LZ4_decompress_fast variants (since v1.9.0) :
- * These functions used to be faster than LZ4_decompress_safe(),
- * but this is no longer the case. They are now slower.
- * This is because LZ4_decompress_fast() doesn't know the input size,
- * and therefore must progress more cautiously into the input buffer to not read beyond the end of block.
- * On top of that `LZ4_decompress_fast()` is not protected vs malformed or malicious inputs, making it a security liability.
- * As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated.
- *
- * The last remaining LZ4_decompress_fast() specificity is that
- * it can decompress a block without knowing its compressed size.
- * Such functionality can be achieved in a more secure manner
- * by employing LZ4_decompress_safe_partial().
- *
- * Parameters:
- * originalSize : is the uncompressed size to regenerate.
- * `dst` must be already allocated, its size must be >= 'originalSize' bytes.
- * @return : number of bytes read from source buffer (== compressed size).
- * The function expects to finish at block's end exactly.
- * If the source stream is detected malformed, the function stops decoding and returns a negative result.
- * note : LZ4_decompress_fast*() requires originalSize. Thanks to this information, it never writes past the output buffer.
- * However, since it doesn't know its 'src' size, it may read an unknown amount of input, past input buffer bounds.
- * Also, since match offsets are not validated, match reads from 'src' may underflow too.
- * These issues never happen if input (compressed) data is correct.
- * But they may happen if input data is invalid (error or intentional tampering).
- * As a consequence, use these functions in trusted environments with trusted data **only**.
- */
- LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe() instead")
- LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
- LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_continue() instead")
- LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize);
- LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_usingDict() instead")
- LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize);
- /*! LZ4_resetStream() :
- * An LZ4_stream_t structure must be initialized at least once.
- * This is done with LZ4_initStream(), or LZ4_resetStream().
- * Consider switching to LZ4_initStream(),
- * invoking LZ4_resetStream() will trigger deprecation warnings in the future.
- */
- LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr);
- #endif /* LZ4_H_98237428734687 */
- #if defined (__cplusplus)
- }
- #endif
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