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0001 /* 0002 * LZ4 - Fast LZ compression algorithm 0003 * Header File 0004 * Copyright (C) 2011-2020, Yann Collet. 0005 0006 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 0007 0008 Redistribution and use in source and binary forms, with or without 0009 modification, are permitted provided that the following conditions are 0010 met: 0011 0012 * Redistributions of source code must retain the above copyright 0013 notice, this list of conditions and the following disclaimer. 0014 * Redistributions in binary form must reproduce the above 0015 copyright notice, this list of conditions and the following disclaimer 0016 in the documentation and/or other materials provided with the 0017 distribution. 0018 0019 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 0020 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 0021 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 0022 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 0023 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 0024 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 0025 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 0026 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 0027 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 0028 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 0029 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 0030 0031 You can contact the author at : 0032 - LZ4 homepage : http://www.lz4.org 0033 - LZ4 source repository : https://github.com/lz4/lz4 0034 */ 0035 #if defined (__cplusplus) 0036 extern "C" { 0037 #endif 0038 0039 #ifndef LZ4_H_2983827168210 0040 #define LZ4_H_2983827168210 0041 0042 /* --- Dependency --- */ 0043 #include <stddef.h> /* size_t */ 0044 0045 0046 /** 0047 Introduction 0048 0049 LZ4 is lossless compression algorithm, providing compression speed >500 MB/s per core, 0050 scalable with multi-cores CPU. It features an extremely fast decoder, with speed in 0051 multiple GB/s per core, typically reaching RAM speed limits on multi-core systems. 0052 0053 The LZ4 compression library provides in-memory compression and decompression functions. 0054 It gives full buffer control to user. 0055 Compression can be done in: 0056 - a single step (described as Simple Functions) 0057 - a single step, reusing a context (described in Advanced Functions) 0058 - unbounded multiple steps (described as Streaming compression) 0059 0060 lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md). 0061 Decompressing such a compressed block requires additional metadata. 0062 Exact metadata depends on exact decompression function. 0063 For the typical case of LZ4_decompress_safe(), 0064 metadata includes block's compressed size, and maximum bound of decompressed size. 0065 Each application is free to encode and pass such metadata in whichever way it wants. 0066 0067 lz4.h only handle blocks, it can not generate Frames. 0068 0069 Blocks are different from Frames (doc/lz4_Frame_format.md). 0070 Frames bundle both blocks and metadata in a specified manner. 0071 Embedding metadata is required for compressed data to be self-contained and portable. 0072 Frame format is delivered through a companion API, declared in lz4frame.h. 0073 The `lz4` CLI can only manage frames. 0074 */ 0075 0076 /*^*************************************************************** 0077 * Export parameters 0078 *****************************************************************/ 0079 /* 0080 * LZ4_DLL_EXPORT : 0081 * Enable exporting of functions when building a Windows DLL 0082 * LZ4LIB_VISIBILITY : 0083 * Control library symbols visibility. 0084 */ 0085 #ifndef LZ4LIB_VISIBILITY 0086 # if defined(__GNUC__) && (__GNUC__ >= 4) 0087 # define LZ4LIB_VISIBILITY __attribute__ ((visibility ("default"))) 0088 # else 0089 # define LZ4LIB_VISIBILITY 0090 # endif 0091 #endif 0092 #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1) 0093 # define LZ4LIB_API __declspec(dllexport) LZ4LIB_VISIBILITY 0094 #elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1) 0095 # 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.*/ 0096 #else 0097 # define LZ4LIB_API LZ4LIB_VISIBILITY 0098 #endif 0099 0100 /*! LZ4_FREESTANDING : 0101 * When this macro is set to 1, it enables "freestanding mode" that is 0102 * suitable for typical freestanding environment which doesn't support 0103 * standard C library. 0104 * 0105 * - LZ4_FREESTANDING is a compile-time switch. 0106 * - It requires the following macros to be defined: 0107 * LZ4_memcpy, LZ4_memmove, LZ4_memset. 0108 * - It only enables LZ4/HC functions which don't use heap. 0109 * All LZ4F_* functions are not supported. 0110 * - See tests/freestanding.c to check its basic setup. 0111 */ 0112 #if defined(LZ4_FREESTANDING) && (LZ4_FREESTANDING == 1) 0113 # define LZ4_HEAPMODE 0 0114 # define LZ4HC_HEAPMODE 0 0115 # define LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION 1 0116 # if !defined(LZ4_memcpy) 0117 # error "LZ4_FREESTANDING requires macro 'LZ4_memcpy'." 0118 # endif 0119 # if !defined(LZ4_memset) 0120 # error "LZ4_FREESTANDING requires macro 'LZ4_memset'." 0121 # endif 0122 # if !defined(LZ4_memmove) 0123 # error "LZ4_FREESTANDING requires macro 'LZ4_memmove'." 0124 # endif 0125 #elif ! defined(LZ4_FREESTANDING) 0126 # define LZ4_FREESTANDING 0 0127 #endif 0128 0129 0130 /*------ Version ------*/ 0131 #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */ 0132 #define LZ4_VERSION_MINOR 9 /* for new (non-breaking) interface capabilities */ 0133 #define LZ4_VERSION_RELEASE 4 /* for tweaks, bug-fixes, or development */ 0134 0135 #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE) 0136 0137 #define LZ4_LIB_VERSION LZ4_VERSION_MAJOR.LZ4_VERSION_MINOR.LZ4_VERSION_RELEASE 0138 #define LZ4_QUOTE(str) #str 0139 #define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str) 0140 #define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION) /* requires v1.7.3+ */ 0141 0142 LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version; requires v1.3.0+ */ 0143 LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; useful to check dll version; requires v1.7.5+ */ 0144 0145 0146 /*-************************************ 0147 * Tuning parameter 0148 **************************************/ 0149 #define LZ4_MEMORY_USAGE_MIN 10 0150 #define LZ4_MEMORY_USAGE_DEFAULT 14 0151 #define LZ4_MEMORY_USAGE_MAX 20 0152 0153 /*! 0154 * LZ4_MEMORY_USAGE : 0155 * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; ) 0156 * Increasing memory usage improves compression ratio, at the cost of speed. 0157 * Reduced memory usage may improve speed at the cost of ratio, thanks to better cache locality. 0158 * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache 0159 */ 0160 #ifndef LZ4_MEMORY_USAGE 0161 # define LZ4_MEMORY_USAGE LZ4_MEMORY_USAGE_DEFAULT 0162 #endif 0163 0164 #if (LZ4_MEMORY_USAGE < LZ4_MEMORY_USAGE_MIN) 0165 # error "LZ4_MEMORY_USAGE is too small !" 0166 #endif 0167 0168 #if (LZ4_MEMORY_USAGE > LZ4_MEMORY_USAGE_MAX) 0169 # error "LZ4_MEMORY_USAGE is too large !" 0170 #endif 0171 0172 /*-************************************ 0173 * Simple Functions 0174 **************************************/ 0175 /*! LZ4_compress_default() : 0176 * Compresses 'srcSize' bytes from buffer 'src' 0177 * into already allocated 'dst' buffer of size 'dstCapacity'. 0178 * Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize). 0179 * It also runs faster, so it's a recommended setting. 0180 * If the function cannot compress 'src' into a more limited 'dst' budget, 0181 * compression stops *immediately*, and the function result is zero. 0182 * In which case, 'dst' content is undefined (invalid). 0183 * srcSize : max supported value is LZ4_MAX_INPUT_SIZE. 0184 * dstCapacity : size of buffer 'dst' (which must be already allocated) 0185 * @return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) 0186 * or 0 if compression fails 0187 * Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer). 0188 */ 0189 LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity); 0190 0191 /*! LZ4_decompress_safe() : 0192 * compressedSize : is the exact complete size of the compressed block. 0193 * dstCapacity : is the size of destination buffer (which must be already allocated), presumed an upper bound of decompressed size. 0194 * @return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity) 0195 * If destination buffer is not large enough, decoding will stop and output an error code (negative value). 0196 * If the source stream is detected malformed, the function will stop decoding and return a negative result. 0197 * Note 1 : This function is protected against malicious data packets : 0198 * it will never writes outside 'dst' buffer, nor read outside 'source' buffer, 0199 * even if the compressed block is maliciously modified to order the decoder to do these actions. 0200 * In such case, the decoder stops immediately, and considers the compressed block malformed. 0201 * Note 2 : compressedSize and dstCapacity must be provided to the function, the compressed block does not contain them. 0202 * The implementation is free to send / store / derive this information in whichever way is most beneficial. 0203 * If there is a need for a different format which bundles together both compressed data and its metadata, consider looking at lz4frame.h instead. 0204 */ 0205 LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity); 0206 0207 0208 /*-************************************ 0209 * Advanced Functions 0210 **************************************/ 0211 #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ 0212 #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16) 0213 0214 /*! LZ4_compressBound() : 0215 Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) 0216 This function is primarily useful for memory allocation purposes (destination buffer size). 0217 Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). 0218 Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize) 0219 inputSize : max supported value is LZ4_MAX_INPUT_SIZE 0220 return : maximum output size in a "worst case" scenario 0221 or 0, if input size is incorrect (too large or negative) 0222 */ 0223 LZ4LIB_API int LZ4_compressBound(int inputSize); 0224 0225 /*! LZ4_compress_fast() : 0226 Same as LZ4_compress_default(), but allows selection of "acceleration" factor. 0227 The larger the acceleration value, the faster the algorithm, but also the lesser the compression. 0228 It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed. 0229 An acceleration value of "1" is the same as regular LZ4_compress_default() 0230 Values <= 0 will be replaced by LZ4_ACCELERATION_DEFAULT (currently == 1, see lz4.c). 0231 Values > LZ4_ACCELERATION_MAX will be replaced by LZ4_ACCELERATION_MAX (currently == 65537, see lz4.c). 0232 */ 0233 LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); 0234 0235 0236 /*! LZ4_compress_fast_extState() : 0237 * Same as LZ4_compress_fast(), using an externally allocated memory space for its state. 0238 * Use LZ4_sizeofState() to know how much memory must be allocated, 0239 * and allocate it on 8-bytes boundaries (using `malloc()` typically). 0240 * Then, provide this buffer as `void* state` to compression function. 0241 */ 0242 LZ4LIB_API int LZ4_sizeofState(void); 0243 LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); 0244 0245 0246 /*! LZ4_compress_destSize() : 0247 * Reverse the logic : compresses as much data as possible from 'src' buffer 0248 * into already allocated buffer 'dst', of size >= 'targetDestSize'. 0249 * This function either compresses the entire 'src' content into 'dst' if it's large enough, 0250 * or fill 'dst' buffer completely with as much data as possible from 'src'. 0251 * note: acceleration parameter is fixed to "default". 0252 * 0253 * *srcSizePtr : will be modified to indicate how many bytes where read from 'src' to fill 'dst'. 0254 * New value is necessarily <= input value. 0255 * @return : Nb bytes written into 'dst' (necessarily <= targetDestSize) 0256 * or 0 if compression fails. 0257 * 0258 * Note : from v1.8.2 to v1.9.1, this function had a bug (fixed un v1.9.2+): 0259 * the produced compressed content could, in specific circumstances, 0260 * require to be decompressed into a destination buffer larger 0261 * by at least 1 byte than the content to decompress. 0262 * If an application uses `LZ4_compress_destSize()`, 0263 * it's highly recommended to update liblz4 to v1.9.2 or better. 0264 * If this can't be done or ensured, 0265 * the receiving decompression function should provide 0266 * a dstCapacity which is > decompressedSize, by at least 1 byte. 0267 * See https://github.com/lz4/lz4/issues/859 for details 0268 */ 0269 LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize); 0270 0271 0272 /*! LZ4_decompress_safe_partial() : 0273 * Decompress an LZ4 compressed block, of size 'srcSize' at position 'src', 0274 * into destination buffer 'dst' of size 'dstCapacity'. 0275 * Up to 'targetOutputSize' bytes will be decoded. 0276 * The function stops decoding on reaching this objective. 0277 * This can be useful to boost performance 0278 * whenever only the beginning of a block is required. 0279 * 0280 * @return : the number of bytes decoded in `dst` (necessarily <= targetOutputSize) 0281 * If source stream is detected malformed, function returns a negative result. 0282 * 0283 * Note 1 : @return can be < targetOutputSize, if compressed block contains less data. 0284 * 0285 * Note 2 : targetOutputSize must be <= dstCapacity 0286 * 0287 * Note 3 : this function effectively stops decoding on reaching targetOutputSize, 0288 * so dstCapacity is kind of redundant. 0289 * This is because in older versions of this function, 0290 * decoding operation would still write complete sequences. 0291 * Therefore, there was no guarantee that it would stop writing at exactly targetOutputSize, 0292 * it could write more bytes, though only up to dstCapacity. 0293 * Some "margin" used to be required for this operation to work properly. 0294 * Thankfully, this is no longer necessary. 0295 * The function nonetheless keeps the same signature, in an effort to preserve API compatibility. 0296 * 0297 * Note 4 : If srcSize is the exact size of the block, 0298 * then targetOutputSize can be any value, 0299 * including larger than the block's decompressed size. 0300 * The function will, at most, generate block's decompressed size. 0301 * 0302 * Note 5 : If srcSize is _larger_ than block's compressed size, 0303 * then targetOutputSize **MUST** be <= block's decompressed size. 0304 * Otherwise, *silent corruption will occur*. 0305 */ 0306 LZ4LIB_API int LZ4_decompress_safe_partial (const char* src, char* dst, int srcSize, int targetOutputSize, int dstCapacity); 0307 0308 0309 /*-********************************************* 0310 * Streaming Compression Functions 0311 ***********************************************/ 0312 typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */ 0313 0314 /** 0315 Note about RC_INVOKED 0316 0317 - RC_INVOKED is predefined symbol of rc.exe (the resource compiler which is part of MSVC/Visual Studio). 0318 https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros 0319 0320 - Since rc.exe is a legacy compiler, it truncates long symbol (> 30 chars) 0321 and reports warning "RC4011: identifier truncated". 0322 0323 - To eliminate the warning, we surround long preprocessor symbol with 0324 "#if !defined(RC_INVOKED) ... #endif" block that means 0325 "skip this block when rc.exe is trying to read it". 0326 */ 0327 #if !defined(RC_INVOKED) /* https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros */ 0328 #if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) 0329 LZ4LIB_API LZ4_stream_t* LZ4_createStream(void); 0330 LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr); 0331 #endif /* !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) */ 0332 #endif 0333 0334 /*! LZ4_resetStream_fast() : v1.9.0+ 0335 * Use this to prepare an LZ4_stream_t for a new chain of dependent blocks 0336 * (e.g., LZ4_compress_fast_continue()). 0337 * 0338 * An LZ4_stream_t must be initialized once before usage. 0339 * This is automatically done when created by LZ4_createStream(). 0340 * However, should the LZ4_stream_t be simply declared on stack (for example), 0341 * it's necessary to initialize it first, using LZ4_initStream(). 0342 * 0343 * After init, start any new stream with LZ4_resetStream_fast(). 0344 * A same LZ4_stream_t can be re-used multiple times consecutively 0345 * and compress multiple streams, 0346 * provided that it starts each new stream with LZ4_resetStream_fast(). 0347 * 0348 * LZ4_resetStream_fast() is much faster than LZ4_initStream(), 0349 * but is not compatible with memory regions containing garbage data. 0350 * 0351 * Note: it's only useful to call LZ4_resetStream_fast() 0352 * in the context of streaming compression. 0353 * The *extState* functions perform their own resets. 0354 * Invoking LZ4_resetStream_fast() before is redundant, and even counterproductive. 0355 */ 0356 LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr); 0357 0358 /*! LZ4_loadDict() : 0359 * Use this function to reference a static dictionary into LZ4_stream_t. 0360 * The dictionary must remain available during compression. 0361 * LZ4_loadDict() triggers a reset, so any previous data will be forgotten. 0362 * The same dictionary will have to be loaded on decompression side for successful decoding. 0363 * Dictionary are useful for better compression of small data (KB range). 0364 * While LZ4 accept any input as dictionary, 0365 * results are generally better when using Zstandard's Dictionary Builder. 0366 * Loading a size of 0 is allowed, and is the same as reset. 0367 * @return : loaded dictionary size, in bytes (necessarily <= 64 KB) 0368 */ 0369 LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize); 0370 0371 /*! LZ4_compress_fast_continue() : 0372 * Compress 'src' content using data from previously compressed blocks, for better compression ratio. 0373 * 'dst' buffer must be already allocated. 0374 * If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster. 0375 * 0376 * @return : size of compressed block 0377 * or 0 if there is an error (typically, cannot fit into 'dst'). 0378 * 0379 * Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block. 0380 * Each block has precise boundaries. 0381 * Each block must be decompressed separately, calling LZ4_decompress_*() with relevant metadata. 0382 * It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together. 0383 * 0384 * Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory ! 0385 * 0386 * Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB. 0387 * Make sure that buffers are separated, by at least one byte. 0388 * This construction ensures that each block only depends on previous block. 0389 * 0390 * Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB. 0391 * 0392 * Note 5 : After an error, the stream status is undefined (invalid), it can only be reset or freed. 0393 */ 0394 LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); 0395 0396 /*! LZ4_saveDict() : 0397 * If last 64KB data cannot be guaranteed to remain available at its current memory location, 0398 * save it into a safer place (char* safeBuffer). 0399 * This is schematically equivalent to a memcpy() followed by LZ4_loadDict(), 0400 * but is much faster, because LZ4_saveDict() doesn't need to rebuild tables. 0401 * @return : saved dictionary size in bytes (necessarily <= maxDictSize), or 0 if error. 0402 */ 0403 LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int maxDictSize); 0404 0405 0406 /*-********************************************** 0407 * Streaming Decompression Functions 0408 * Bufferless synchronous API 0409 ************************************************/ 0410 typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* tracking context */ 0411 0412 /*! LZ4_createStreamDecode() and LZ4_freeStreamDecode() : 0413 * creation / destruction of streaming decompression tracking context. 0414 * A tracking context can be re-used multiple times. 0415 */ 0416 #if !defined(RC_INVOKED) /* https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros */ 0417 #if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) 0418 LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void); 0419 LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream); 0420 #endif /* !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) */ 0421 #endif 0422 0423 /*! LZ4_setStreamDecode() : 0424 * An LZ4_streamDecode_t context can be allocated once and re-used multiple times. 0425 * Use this function to start decompression of a new stream of blocks. 0426 * A dictionary can optionally be set. Use NULL or size 0 for a reset order. 0427 * Dictionary is presumed stable : it must remain accessible and unmodified during next decompression. 0428 * @return : 1 if OK, 0 if error 0429 */ 0430 LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize); 0431 0432 /*! LZ4_decoderRingBufferSize() : v1.8.2+ 0433 * Note : in a ring buffer scenario (optional), 0434 * blocks are presumed decompressed next to each other 0435 * up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize), 0436 * at which stage it resumes from beginning of ring buffer. 0437 * When setting such a ring buffer for streaming decompression, 0438 * provides the minimum size of this ring buffer 0439 * to be compatible with any source respecting maxBlockSize condition. 0440 * @return : minimum ring buffer size, 0441 * or 0 if there is an error (invalid maxBlockSize). 0442 */ 0443 LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize); 0444 #define LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize) (65536 + 14 + (maxBlockSize)) /* for static allocation; maxBlockSize presumed valid */ 0445 0446 /*! LZ4_decompress_*_continue() : 0447 * These decoding functions allow decompression of consecutive blocks in "streaming" mode. 0448 * A block is an unsplittable entity, it must be presented entirely to a decompression function. 0449 * Decompression functions only accepts one block at a time. 0450 * The last 64KB of previously decoded data *must* remain available and unmodified at the memory position where they were decoded. 0451 * If less than 64KB of data has been decoded, all the data must be present. 0452 * 0453 * Special : if decompression side sets a ring buffer, it must respect one of the following conditions : 0454 * - Decompression buffer size is _at least_ LZ4_decoderRingBufferSize(maxBlockSize). 0455 * maxBlockSize is the maximum size of any single block. It can have any value > 16 bytes. 0456 * In which case, encoding and decoding buffers do not need to be synchronized. 0457 * Actually, data can be produced by any source compliant with LZ4 format specification, and respecting maxBlockSize. 0458 * - Synchronized mode : 0459 * Decompression buffer size is _exactly_ the same as compression buffer size, 0460 * and follows exactly same update rule (block boundaries at same positions), 0461 * and decoding function is provided with exact decompressed size of each block (exception for last block of the stream), 0462 * _then_ decoding & encoding ring buffer can have any size, including small ones ( < 64 KB). 0463 * - Decompression buffer is larger than encoding buffer, by a minimum of maxBlockSize more bytes. 0464 * In which case, encoding and decoding buffers do not need to be synchronized, 0465 * and encoding ring buffer can have any size, including small ones ( < 64 KB). 0466 * 0467 * Whenever these conditions are not possible, 0468 * save the last 64KB of decoded data into a safe buffer where it can't be modified during decompression, 0469 * then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block. 0470 */ 0471 LZ4LIB_API int 0472 LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, 0473 const char* src, char* dst, 0474 int srcSize, int dstCapacity); 0475 0476 0477 /*! LZ4_decompress_*_usingDict() : 0478 * These decoding functions work the same as 0479 * a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue() 0480 * They are stand-alone, and don't need an LZ4_streamDecode_t structure. 0481 * Dictionary is presumed stable : it must remain accessible and unmodified during decompression. 0482 * Performance tip : Decompression speed can be substantially increased 0483 * when dst == dictStart + dictSize. 0484 */ 0485 LZ4LIB_API int 0486 LZ4_decompress_safe_usingDict(const char* src, char* dst, 0487 int srcSize, int dstCapacity, 0488 const char* dictStart, int dictSize); 0489 0490 LZ4LIB_API int 0491 LZ4_decompress_safe_partial_usingDict(const char* src, char* dst, 0492 int compressedSize, 0493 int targetOutputSize, int maxOutputSize, 0494 const char* dictStart, int dictSize); 0495 0496 #endif /* LZ4_H_2983827168210 */ 0497 0498 0499 /*^************************************* 0500 * !!!!!! STATIC LINKING ONLY !!!!!! 0501 ***************************************/ 0502 0503 /*-**************************************************************************** 0504 * Experimental section 0505 * 0506 * Symbols declared in this section must be considered unstable. Their 0507 * signatures or semantics may change, or they may be removed altogether in the 0508 * future. They are therefore only safe to depend on when the caller is 0509 * statically linked against the library. 0510 * 0511 * To protect against unsafe usage, not only are the declarations guarded, 0512 * the definitions are hidden by default 0513 * when building LZ4 as a shared/dynamic library. 0514 * 0515 * In order to access these declarations, 0516 * define LZ4_STATIC_LINKING_ONLY in your application 0517 * before including LZ4's headers. 0518 * 0519 * In order to make their implementations accessible dynamically, you must 0520 * define LZ4_PUBLISH_STATIC_FUNCTIONS when building the LZ4 library. 0521 ******************************************************************************/ 0522 0523 #ifdef LZ4_STATIC_LINKING_ONLY 0524 0525 #ifndef LZ4_STATIC_3504398509 0526 #define LZ4_STATIC_3504398509 0527 0528 #ifdef LZ4_PUBLISH_STATIC_FUNCTIONS 0529 #define LZ4LIB_STATIC_API LZ4LIB_API 0530 #else 0531 #define LZ4LIB_STATIC_API 0532 #endif 0533 0534 0535 /*! LZ4_compress_fast_extState_fastReset() : 0536 * A variant of LZ4_compress_fast_extState(). 0537 * 0538 * Using this variant avoids an expensive initialization step. 0539 * It is only safe to call if the state buffer is known to be correctly initialized already 0540 * (see above comment on LZ4_resetStream_fast() for a definition of "correctly initialized"). 0541 * From a high level, the difference is that 0542 * this function initializes the provided state with a call to something like LZ4_resetStream_fast() 0543 * while LZ4_compress_fast_extState() starts with a call to LZ4_resetStream(). 0544 */ 0545 LZ4LIB_STATIC_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); 0546 0547 /*! LZ4_attach_dictionary() : 0548 * This is an experimental API that allows 0549 * efficient use of a static dictionary many times. 0550 * 0551 * Rather than re-loading the dictionary buffer into a working context before 0552 * each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a 0553 * working LZ4_stream_t, this function introduces a no-copy setup mechanism, 0554 * in which the working stream references the dictionary stream in-place. 0555 * 0556 * Several assumptions are made about the state of the dictionary stream. 0557 * Currently, only streams which have been prepared by LZ4_loadDict() should 0558 * be expected to work. 0559 * 0560 * Alternatively, the provided dictionaryStream may be NULL, 0561 * in which case any existing dictionary stream is unset. 0562 * 0563 * If a dictionary is provided, it replaces any pre-existing stream history. 0564 * The dictionary contents are the only history that can be referenced and 0565 * logically immediately precede the data compressed in the first subsequent 0566 * compression call. 0567 * 0568 * The dictionary will only remain attached to the working stream through the 0569 * first compression call, at the end of which it is cleared. The dictionary 0570 * stream (and source buffer) must remain in-place / accessible / unchanged 0571 * through the completion of the first compression call on the stream. 0572 */ 0573 LZ4LIB_STATIC_API void 0574 LZ4_attach_dictionary(LZ4_stream_t* workingStream, 0575 const LZ4_stream_t* dictionaryStream); 0576 0577 0578 /*! In-place compression and decompression 0579 * 0580 * It's possible to have input and output sharing the same buffer, 0581 * for highly constrained memory environments. 0582 * In both cases, it requires input to lay at the end of the buffer, 0583 * and decompression to start at beginning of the buffer. 0584 * Buffer size must feature some margin, hence be larger than final size. 0585 * 0586 * |<------------------------buffer--------------------------------->| 0587 * |<-----------compressed data--------->| 0588 * |<-----------decompressed size------------------>| 0589 * |<----margin---->| 0590 * 0591 * This technique is more useful for decompression, 0592 * since decompressed size is typically larger, 0593 * and margin is short. 0594 * 0595 * In-place decompression will work inside any buffer 0596 * which size is >= LZ4_DECOMPRESS_INPLACE_BUFFER_SIZE(decompressedSize). 0597 * This presumes that decompressedSize > compressedSize. 0598 * Otherwise, it means compression actually expanded data, 0599 * and it would be more efficient to store such data with a flag indicating it's not compressed. 0600 * This can happen when data is not compressible (already compressed, or encrypted). 0601 * 0602 * For in-place compression, margin is larger, as it must be able to cope with both 0603 * history preservation, requiring input data to remain unmodified up to LZ4_DISTANCE_MAX, 0604 * and data expansion, which can happen when input is not compressible. 0605 * As a consequence, buffer size requirements are much higher, 0606 * and memory savings offered by in-place compression are more limited. 0607 * 0608 * There are ways to limit this cost for compression : 0609 * - Reduce history size, by modifying LZ4_DISTANCE_MAX. 0610 * Note that it is a compile-time constant, so all compressions will apply this limit. 0611 * Lower values will reduce compression ratio, except when input_size < LZ4_DISTANCE_MAX, 0612 * so it's a reasonable trick when inputs are known to be small. 0613 * - Require the compressor to deliver a "maximum compressed size". 0614 * This is the `dstCapacity` parameter in `LZ4_compress*()`. 0615 * When this size is < LZ4_COMPRESSBOUND(inputSize), then compression can fail, 0616 * in which case, the return code will be 0 (zero). 0617 * The caller must be ready for these cases to happen, 0618 * and typically design a backup scheme to send data uncompressed. 0619 * The combination of both techniques can significantly reduce 0620 * the amount of margin required for in-place compression. 0621 * 0622 * In-place compression can work in any buffer 0623 * which size is >= (maxCompressedSize) 0624 * with maxCompressedSize == LZ4_COMPRESSBOUND(srcSize) for guaranteed compression success. 0625 * LZ4_COMPRESS_INPLACE_BUFFER_SIZE() depends on both maxCompressedSize and LZ4_DISTANCE_MAX, 0626 * so it's possible to reduce memory requirements by playing with them. 0627 */ 0628 0629 #define LZ4_DECOMPRESS_INPLACE_MARGIN(compressedSize) (((compressedSize) >> 8) + 32) 0630 #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 */ 0631 0632 #ifndef LZ4_DISTANCE_MAX /* history window size; can be user-defined at compile time */ 0633 # define LZ4_DISTANCE_MAX 65535 /* set to maximum value by default */ 0634 #endif 0635 0636 #define LZ4_COMPRESS_INPLACE_MARGIN (LZ4_DISTANCE_MAX + 32) /* LZ4_DISTANCE_MAX can be safely replaced by srcSize when it's smaller */ 0637 #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)) */ 0638 0639 #endif /* LZ4_STATIC_3504398509 */ 0640 #endif /* LZ4_STATIC_LINKING_ONLY */ 0641 0642 0643 0644 #ifndef LZ4_H_98237428734687 0645 #define LZ4_H_98237428734687 0646 0647 /*-************************************************************ 0648 * Private Definitions 0649 ************************************************************** 0650 * Do not use these definitions directly. 0651 * They are only exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`. 0652 * Accessing members will expose user code to API and/or ABI break in future versions of the library. 0653 **************************************************************/ 0654 #define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2) 0655 #define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE) 0656 #define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */ 0657 0658 #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) 0659 # include <stdint.h> 0660 typedef int8_t LZ4_i8; 0661 typedef uint8_t LZ4_byte; 0662 typedef uint16_t LZ4_u16; 0663 typedef uint32_t LZ4_u32; 0664 #else 0665 typedef signed char LZ4_i8; 0666 typedef unsigned char LZ4_byte; 0667 typedef unsigned short LZ4_u16; 0668 typedef unsigned int LZ4_u32; 0669 #endif 0670 0671 /*! LZ4_stream_t : 0672 * Never ever use below internal definitions directly ! 0673 * These definitions are not API/ABI safe, and may change in future versions. 0674 * If you need static allocation, declare or allocate an LZ4_stream_t object. 0675 **/ 0676 0677 typedef struct LZ4_stream_t_internal LZ4_stream_t_internal; 0678 struct LZ4_stream_t_internal { 0679 LZ4_u32 hashTable[LZ4_HASH_SIZE_U32]; 0680 const LZ4_byte* dictionary; 0681 const LZ4_stream_t_internal* dictCtx; 0682 LZ4_u32 currentOffset; 0683 LZ4_u32 tableType; 0684 LZ4_u32 dictSize; 0685 /* Implicit padding to ensure structure is aligned */ 0686 }; 0687 0688 #define LZ4_STREAM_MINSIZE ((1UL << LZ4_MEMORY_USAGE) + 32) /* static size, for inter-version compatibility */ 0689 union LZ4_stream_u { 0690 char minStateSize[LZ4_STREAM_MINSIZE]; 0691 LZ4_stream_t_internal internal_donotuse; 0692 }; /* previously typedef'd to LZ4_stream_t */ 0693 0694 0695 /*! LZ4_initStream() : v1.9.0+ 0696 * An LZ4_stream_t structure must be initialized at least once. 0697 * This is automatically done when invoking LZ4_createStream(), 0698 * but it's not when the structure is simply declared on stack (for example). 0699 * 0700 * Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t. 0701 * It can also initialize any arbitrary buffer of sufficient size, 0702 * and will @return a pointer of proper type upon initialization. 0703 * 0704 * Note : initialization fails if size and alignment conditions are not respected. 0705 * In which case, the function will @return NULL. 0706 * Note2: An LZ4_stream_t structure guarantees correct alignment and size. 0707 * Note3: Before v1.9.0, use LZ4_resetStream() instead 0708 **/ 0709 LZ4LIB_API LZ4_stream_t* LZ4_initStream (void* buffer, size_t size); 0710 0711 0712 /*! LZ4_streamDecode_t : 0713 * Never ever use below internal definitions directly ! 0714 * These definitions are not API/ABI safe, and may change in future versions. 0715 * If you need static allocation, declare or allocate an LZ4_streamDecode_t object. 0716 **/ 0717 typedef struct { 0718 const LZ4_byte* externalDict; 0719 const LZ4_byte* prefixEnd; 0720 size_t extDictSize; 0721 size_t prefixSize; 0722 } LZ4_streamDecode_t_internal; 0723 0724 #define LZ4_STREAMDECODE_MINSIZE 32 0725 union LZ4_streamDecode_u { 0726 char minStateSize[LZ4_STREAMDECODE_MINSIZE]; 0727 LZ4_streamDecode_t_internal internal_donotuse; 0728 } ; /* previously typedef'd to LZ4_streamDecode_t */ 0729 0730 0731 0732 /*-************************************ 0733 * Obsolete Functions 0734 **************************************/ 0735 0736 /*! Deprecation warnings 0737 * 0738 * Deprecated functions make the compiler generate a warning when invoked. 0739 * This is meant to invite users to update their source code. 0740 * Should deprecation warnings be a problem, it is generally possible to disable them, 0741 * typically with -Wno-deprecated-declarations for gcc 0742 * or _CRT_SECURE_NO_WARNINGS in Visual. 0743 * 0744 * Another method is to define LZ4_DISABLE_DEPRECATE_WARNINGS 0745 * before including the header file. 0746 */ 0747 #ifdef LZ4_DISABLE_DEPRECATE_WARNINGS 0748 # define LZ4_DEPRECATED(message) /* disable deprecation warnings */ 0749 #else 0750 # if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */ 0751 # define LZ4_DEPRECATED(message) [[deprecated(message)]] 0752 # elif defined(_MSC_VER) 0753 # define LZ4_DEPRECATED(message) __declspec(deprecated(message)) 0754 # elif defined(__clang__) || (defined(__GNUC__) && (__GNUC__ * 10 + __GNUC_MINOR__ >= 45)) 0755 # define LZ4_DEPRECATED(message) __attribute__((deprecated(message))) 0756 # elif defined(__GNUC__) && (__GNUC__ * 10 + __GNUC_MINOR__ >= 31) 0757 # define LZ4_DEPRECATED(message) __attribute__((deprecated)) 0758 # else 0759 # pragma message("WARNING: LZ4_DEPRECATED needs custom implementation for this compiler") 0760 # define LZ4_DEPRECATED(message) /* disabled */ 0761 # endif 0762 #endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */ 0763 0764 /*! Obsolete compression functions (since v1.7.3) */ 0765 LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* src, char* dest, int srcSize); 0766 LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* src, char* dest, int srcSize, int maxOutputSize); 0767 LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize); 0768 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); 0769 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); 0770 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); 0771 0772 /*! Obsolete decompression functions (since v1.8.0) */ 0773 LZ4_DEPRECATED("use LZ4_decompress_fast() instead") LZ4LIB_API int LZ4_uncompress (const char* source, char* dest, int outputSize); 0774 LZ4_DEPRECATED("use LZ4_decompress_safe() instead") LZ4LIB_API int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); 0775 0776 /* Obsolete streaming functions (since v1.7.0) 0777 * degraded functionality; do not use! 0778 * 0779 * In order to perform streaming compression, these functions depended on data 0780 * that is no longer tracked in the state. They have been preserved as well as 0781 * possible: using them will still produce a correct output. However, they don't 0782 * actually retain any history between compression calls. The compression ratio 0783 * achieved will therefore be no better than compressing each chunk 0784 * independently. 0785 */ 0786 LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API void* LZ4_create (char* inputBuffer); 0787 LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API int LZ4_sizeofStreamState(void); 0788 LZ4_DEPRECATED("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void* state, char* inputBuffer); 0789 LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInputBuffer (void* state); 0790 0791 /*! Obsolete streaming decoding functions (since v1.7.0) */ 0792 LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize); 0793 LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize); 0794 0795 /*! Obsolete LZ4_decompress_fast variants (since v1.9.0) : 0796 * These functions used to be faster than LZ4_decompress_safe(), 0797 * but this is no longer the case. They are now slower. 0798 * This is because LZ4_decompress_fast() doesn't know the input size, 0799 * and therefore must progress more cautiously into the input buffer to not read beyond the end of block. 0800 * On top of that `LZ4_decompress_fast()` is not protected vs malformed or malicious inputs, making it a security liability. 0801 * As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated. 0802 * 0803 * The last remaining LZ4_decompress_fast() specificity is that 0804 * it can decompress a block without knowing its compressed size. 0805 * Such functionality can be achieved in a more secure manner 0806 * by employing LZ4_decompress_safe_partial(). 0807 * 0808 * Parameters: 0809 * originalSize : is the uncompressed size to regenerate. 0810 * `dst` must be already allocated, its size must be >= 'originalSize' bytes. 0811 * @return : number of bytes read from source buffer (== compressed size). 0812 * The function expects to finish at block's end exactly. 0813 * If the source stream is detected malformed, the function stops decoding and returns a negative result. 0814 * note : LZ4_decompress_fast*() requires originalSize. Thanks to this information, it never writes past the output buffer. 0815 * However, since it doesn't know its 'src' size, it may read an unknown amount of input, past input buffer bounds. 0816 * Also, since match offsets are not validated, match reads from 'src' may underflow too. 0817 * These issues never happen if input (compressed) data is correct. 0818 * But they may happen if input data is invalid (error or intentional tampering). 0819 * As a consequence, use these functions in trusted environments with trusted data **only**. 0820 */ 0821 LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe() instead") 0822 LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize); 0823 LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_continue() instead") 0824 LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize); 0825 LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_usingDict() instead") 0826 LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize); 0827 0828 /*! LZ4_resetStream() : 0829 * An LZ4_stream_t structure must be initialized at least once. 0830 * This is done with LZ4_initStream(), or LZ4_resetStream(). 0831 * Consider switching to LZ4_initStream(), 0832 * invoking LZ4_resetStream() will trigger deprecation warnings in the future. 0833 */ 0834 LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr); 0835 0836 0837 #endif /* LZ4_H_98237428734687 */ 0838 0839 0840 #if defined (__cplusplus) 0841 } 0842 #endif
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