kopia lustrzana https://github.com/f4exb/sdrangel
361 wiersze
18 KiB
C
361 wiersze
18 KiB
C
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/*
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LZ4 - Fast LZ compression algorithm
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Header File
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Copyright (C) 2011-2015, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- LZ4 source repository : https://github.com/Cyan4973/lz4
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- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
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*/
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#pragma once
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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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* lz4.h provides block compression functions, and gives full buffer control to programmer.
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* If you need to generate inter-operable compressed data (respecting LZ4 frame specification),
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* and can let the library handle its own memory, please use lz4frame.h instead.
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*/
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/**************************************
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* Version
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**************************************/
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#define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
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#define LZ4_VERSION_MINOR 7 /* for new (non-breaking) interface capabilities */
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#define LZ4_VERSION_RELEASE 1 /* for tweaks, bug-fixes, or development */
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#define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
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int LZ4_versionNumber (void);
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/**************************************
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* Tuning parameter
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**************************************/
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/*
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* LZ4_MEMORY_USAGE :
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* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
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* Increasing memory usage improves compression ratio
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* Reduced memory usage can improve speed, due to cache effect
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* Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
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*/
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#define LZ4_MEMORY_USAGE 14
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/**************************************
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* Simple Functions
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**************************************/
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int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize);
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int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
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/*
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LZ4_compress_default() :
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Compresses 'sourceSize' bytes from buffer 'source'
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into already allocated 'dest' buffer of size 'maxDestSize'.
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Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize).
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It also runs faster, so it's a recommended setting.
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If the function cannot compress 'source' into a more limited 'dest' budget,
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compression stops *immediately*, and the function result is zero.
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As a consequence, 'dest' content is not valid.
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This function never writes outside 'dest' buffer, nor read outside 'source' buffer.
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sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE
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maxDestSize : full or partial size of buffer 'dest' (which must be already allocated)
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return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize)
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or 0 if compression fails
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LZ4_decompress_safe() :
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compressedSize : is the precise full size of the compressed block.
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maxDecompressedSize : is the size of destination buffer, which must be already allocated.
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return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize)
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If destination buffer is not large enough, decoding will stop and output an error code (<0).
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If the source stream is detected malformed, the function will stop decoding and return a negative result.
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This function is protected against buffer overflow exploits, including malicious data packets.
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It never writes outside output buffer, nor reads outside input buffer.
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*/
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/**************************************
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* Advanced Functions
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**************************************/
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#define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
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#define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
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/*
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LZ4_compressBound() :
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Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
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This function is primarily useful for memory allocation purposes (destination buffer size).
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Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
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Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize)
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inputSize : max supported value is LZ4_MAX_INPUT_SIZE
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return : maximum output size in a "worst case" scenario
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or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
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*/
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int LZ4_compressBound(int inputSize);
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/*
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LZ4_compress_fast() :
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Same as LZ4_compress_default(), but allows to select an "acceleration" factor.
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The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
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It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
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An acceleration value of "1" is the same as regular LZ4_compress_default()
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Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1.
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*/
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int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration);
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/*
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LZ4_compress_fast_extState() :
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Same compression function, just using an externally allocated memory space to store compression state.
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Use LZ4_sizeofState() to know how much memory must be allocated,
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and allocate it on 8-bytes boundaries (using malloc() typically).
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Then, provide it as 'void* state' to compression function.
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*/
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int LZ4_sizeofState(void);
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int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration);
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/*
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LZ4_compress_destSize() :
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Reverse the logic, by compressing as much data as possible from 'source' buffer
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into already allocated buffer 'dest' of size 'targetDestSize'.
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This function either compresses the entire 'source' content into 'dest' if it's large enough,
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or fill 'dest' buffer completely with as much data as possible from 'source'.
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*sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'.
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New value is necessarily <= old value.
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return : Nb bytes written into 'dest' (necessarily <= targetDestSize)
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or 0 if compression fails
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*/
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int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize);
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/*
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LZ4_decompress_fast() :
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originalSize : is the original and therefore uncompressed size
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return : the number of bytes read from the source buffer (in other words, the compressed size)
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If the source stream is detected malformed, the function will stop decoding and return a negative result.
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Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
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note : This function fully respect memory boundaries for properly formed compressed data.
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It is a bit faster than LZ4_decompress_safe().
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However, it does not provide any protection against intentionally modified data stream (malicious input).
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Use this function in trusted environment only (data to decode comes from a trusted source).
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*/
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int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
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/*
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LZ4_decompress_safe_partial() :
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This function decompress a compressed block of size 'compressedSize' at position 'source'
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into destination buffer 'dest' of size 'maxDecompressedSize'.
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The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
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reducing decompression time.
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return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
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Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
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Always control how many bytes were decoded.
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If the source stream is detected malformed, the function will stop decoding and return a negative result.
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This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
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*/
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int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
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/***********************************************
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* Streaming Compression Functions
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***********************************************/
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#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4)
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#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(long long))
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/*
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* LZ4_stream_t
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* information structure to track an LZ4 stream.
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* important : init this structure content before first use !
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* note : only allocated directly the structure if you are statically linking LZ4
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* If you are using liblz4 as a DLL, please use below construction methods instead.
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*/
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typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t;
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/*
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* LZ4_resetStream
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* Use this function to init an allocated LZ4_stream_t structure
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*/
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void LZ4_resetStream (LZ4_stream_t* streamPtr);
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/*
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* LZ4_createStream will allocate and initialize an LZ4_stream_t structure
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* LZ4_freeStream releases its memory.
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* In the context of a DLL (liblz4), please use these methods rather than the static struct.
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* They are more future proof, in case of a change of LZ4_stream_t size.
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*/
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LZ4_stream_t* LZ4_createStream(void);
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int LZ4_freeStream (LZ4_stream_t* streamPtr);
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/*
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* LZ4_loadDict
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* Use this function to load a static dictionary into LZ4_stream.
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* Any previous data will be forgotten, only 'dictionary' will remain in memory.
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* Loading a size of 0 is allowed.
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* Return : dictionary size, in bytes (necessarily <= 64 KB)
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*/
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int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
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/*
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* LZ4_compress_fast_continue
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* Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
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* Important : Previous data blocks are assumed to still be present and unmodified !
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* 'dst' buffer must be already allocated.
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* If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
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* If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero.
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*/
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int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration);
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/*
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* LZ4_saveDict
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* If previously compressed data block is not guaranteed to remain available at its memory location
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* save it into a safer place (char* safeBuffer)
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* Note : you don't need to call LZ4_loadDict() afterwards,
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* dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue()
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* Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error
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*/
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int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
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/************************************************
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* Streaming Decompression Functions
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************************************************/
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#define LZ4_STREAMDECODESIZE_U64 4
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#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
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typedef struct { unsigned long long table[LZ4_STREAMDECODESIZE_U64]; } LZ4_streamDecode_t;
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/*
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* LZ4_streamDecode_t
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* information structure to track an LZ4 stream.
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* init this structure content using LZ4_setStreamDecode or memset() before first use !
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*
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* In the context of a DLL (liblz4) please prefer usage of construction methods below.
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* They are more future proof, in case of a change of LZ4_streamDecode_t size in the future.
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* LZ4_createStreamDecode will allocate and initialize an LZ4_streamDecode_t structure
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* LZ4_freeStreamDecode releases its memory.
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*/
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LZ4_streamDecode_t* LZ4_createStreamDecode(void);
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int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
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/*
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* LZ4_setStreamDecode
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* Use this function to instruct where to find the dictionary.
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* Setting a size of 0 is allowed (same effect as reset).
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* Return : 1 if OK, 0 if error
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*/
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int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
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/*
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*_continue() :
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These decoding functions allow decompression of multiple blocks in "streaming" mode.
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Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
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In the case of a ring buffers, decoding buffer must be either :
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- Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
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In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
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- Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
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maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
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In which case, encoding and decoding buffers do not need to be synchronized,
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and encoding ring buffer can have any size, including small ones ( < 64 KB).
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- _At least_ 64 KB + 8 bytes + maxBlockSize.
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In which case, encoding and decoding buffers do not need to be synchronized,
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and encoding ring buffer can have any size, including larger than decoding buffer.
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Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
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and indicate where it is saved using LZ4_setStreamDecode()
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*/
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int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
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int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
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/*
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Advanced decoding functions :
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*_usingDict() :
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These decoding functions work the same as
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a combination of LZ4_setStreamDecode() followed by LZ4_decompress_x_continue()
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They are stand-alone. They don't need nor update an LZ4_streamDecode_t structure.
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*/
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int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
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int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
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/**************************************
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* Obsolete Functions
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**************************************/
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/* Deprecate Warnings */
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/* Should these warnings messages be a problem,
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it is generally possible to disable them,
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with -Wno-deprecated-declarations for gcc
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or _CRT_SECURE_NO_WARNINGS in Visual for example.
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You can also define LZ4_DEPRECATE_WARNING_DEFBLOCK. */
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#ifndef LZ4_DEPRECATE_WARNING_DEFBLOCK
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# define LZ4_DEPRECATE_WARNING_DEFBLOCK
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# define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
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# if (LZ4_GCC_VERSION >= 405) || defined(__clang__)
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# define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
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# elif (LZ4_GCC_VERSION >= 301)
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# define LZ4_DEPRECATED(message) __attribute__((deprecated))
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# elif defined(_MSC_VER)
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# define LZ4_DEPRECATED(message) __declspec(deprecated(message))
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# else
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# pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler")
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# define LZ4_DEPRECATED(message)
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# endif
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#endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */
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/* Obsolete compression functions */
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/* These functions are planned to start generate warnings by r131 approximately */
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int LZ4_compress (const char* source, char* dest, int sourceSize);
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int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
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int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
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int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
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int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
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int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
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/* Obsolete decompression functions */
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/* These function names are completely deprecated and must no longer be used.
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They are only provided here for compatibility with older programs.
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- LZ4_uncompress is the same as LZ4_decompress_fast
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- LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
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These function prototypes are now disabled; uncomment them only if you really need them.
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It is highly recommended to stop using these prototypes and migrate to maintained ones */
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/* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
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/* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
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/* Obsolete streaming functions; use new streaming interface whenever possible */
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LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
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LZ4_DEPRECATED("use LZ4_createStream() instead") int LZ4_sizeofStreamState(void);
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LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void* state, char* inputBuffer);
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LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state);
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/* Obsolete streaming decoding functions */
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LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
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LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
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#if defined (__cplusplus)
|
||
|
}
|
||
|
#endif
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