1 #include "svn_private_config.h"
4 * LZ4 - Fast LZ compression algorithm
6 * Copyright (C) 2011-2016, Yann Collet.
8 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
10 Redistribution and use in source and binary forms, with or without
11 modification, are permitted provided that the following conditions are
14 * Redistributions of source code must retain the above copyright
15 notice, this list of conditions and the following disclaimer.
16 * Redistributions in binary form must reproduce the above
17 copyright notice, this list of conditions and the following disclaimer
18 in the documentation and/or other materials provided with the
21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 You can contact the author at :
34 - LZ4 homepage : http://www.lz4.org
35 - LZ4 source repository : https://github.com/lz4/lz4
37 #ifndef LZ4_H_2983827168210
38 #define LZ4_H_2983827168210
40 #if defined (__cplusplus)
44 /* --- Dependency --- */
45 #include <stddef.h> /* size_t */
51 LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s per core,
52 scalable with multi-cores CPU. It features an extremely fast decoder, with speed in
53 multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.
55 The LZ4 compression library provides in-memory compression and decompression functions.
56 Compression can be done in:
57 - a single step (described as Simple Functions)
58 - a single step, reusing a context (described in Advanced Functions)
59 - unbounded multiple steps (described as Streaming compression)
61 lz4.h provides block compression functions. It gives full buffer control to user.
62 Decompressing an lz4-compressed block also requires metadata (such as compressed size).
63 Each application is free to encode such metadata in whichever way it wants.
65 An additional format, called LZ4 frame specification (doc/lz4_Frame_format.md),
66 take care of encoding standard metadata alongside LZ4-compressed blocks.
67 If your application requires interoperability, it's recommended to use it.
68 A library is provided to take care of it, see lz4frame.h.
71 /*^***************************************************************
73 *****************************************************************/
76 * Enable exporting of functions when building a Windows DLL
78 #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
79 # define LZ4LIB_API __declspec(dllexport)
80 #elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
81 # define LZ4LIB_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
87 /*========== Version =========== */
88 #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
89 #define LZ4_VERSION_MINOR 7 /* for new (non-breaking) interface capabilities */
90 #define LZ4_VERSION_RELEASE 5 /* for tweaks, bug-fixes, or development */
92 #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
94 #define LZ4_LIB_VERSION LZ4_VERSION_MAJOR.LZ4_VERSION_MINOR.LZ4_VERSION_RELEASE
95 #define LZ4_QUOTE(str) #str
96 #define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str)
97 #define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)
99 LZ4LIB_API int LZ4_versionNumber (void);
100 LZ4LIB_API const char* LZ4_versionString (void);
103 /*-************************************
105 **************************************/
108 * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
109 * Increasing memory usage improves compression ratio
110 * Reduced memory usage can improve speed, due to cache effect
111 * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
113 #define LZ4_MEMORY_USAGE 14
116 /*-************************************
118 **************************************/
119 /*! LZ4_compress_default() :
120 Compresses 'sourceSize' bytes from buffer 'source'
121 into already allocated 'dest' buffer of size 'maxDestSize'.
122 Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize).
123 It also runs faster, so it's a recommended setting.
124 If the function cannot compress 'source' into a more limited 'dest' budget,
125 compression stops *immediately*, and the function result is zero.
126 As a consequence, 'dest' content is not valid.
127 This function never writes outside 'dest' buffer, nor read outside 'source' buffer.
128 sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE
129 maxDestSize : full or partial size of buffer 'dest' (which must be already allocated)
130 return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize)
131 or 0 if compression fails */
132 LZ4LIB_API int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize);
134 /*! LZ4_decompress_safe() :
135 compressedSize : is the precise full size of the compressed block.
136 maxDecompressedSize : is the size of destination buffer, which must be already allocated.
137 return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize)
138 If destination buffer is not large enough, decoding will stop and output an error code (<0).
139 If the source stream is detected malformed, the function will stop decoding and return a negative result.
140 This function is protected against buffer overflow exploits, including malicious data packets.
141 It never writes outside output buffer, nor reads outside input buffer.
143 LZ4LIB_API int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
146 /*-************************************
148 **************************************/
149 #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
150 #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
153 LZ4_compressBound() :
154 Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
155 This function is primarily useful for memory allocation purposes (destination buffer size).
156 Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
157 Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize)
158 inputSize : max supported value is LZ4_MAX_INPUT_SIZE
159 return : maximum output size in a "worst case" scenario
160 or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
162 LZ4LIB_API int LZ4_compressBound(int inputSize);
165 LZ4_compress_fast() :
166 Same as LZ4_compress_default(), but allows to select an "acceleration" factor.
167 The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
168 It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
169 An acceleration value of "1" is the same as regular LZ4_compress_default()
170 Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1.
172 LZ4LIB_API int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration);
176 LZ4_compress_fast_extState() :
177 Same compression function, just using an externally allocated memory space to store compression state.
178 Use LZ4_sizeofState() to know how much memory must be allocated,
179 and allocate it on 8-bytes boundaries (using malloc() typically).
180 Then, provide it as 'void* state' to compression function.
182 LZ4LIB_API int LZ4_sizeofState(void);
183 LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration);
187 LZ4_compress_destSize() :
188 Reverse the logic, by compressing as much data as possible from 'source' buffer
189 into already allocated buffer 'dest' of size 'targetDestSize'.
190 This function either compresses the entire 'source' content into 'dest' if it's large enough,
191 or fill 'dest' buffer completely with as much data as possible from 'source'.
192 *sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'.
193 New value is necessarily <= old value.
194 return : Nb bytes written into 'dest' (necessarily <= targetDestSize)
195 or 0 if compression fails
197 LZ4LIB_API int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize);
201 LZ4_decompress_fast() :
202 originalSize : is the original and therefore uncompressed size
203 return : the number of bytes read from the source buffer (in other words, the compressed size)
204 If the source stream is detected malformed, the function will stop decoding and return a negative result.
205 Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
206 note : This function fully respect memory boundaries for properly formed compressed data.
207 It is a bit faster than LZ4_decompress_safe().
208 However, it does not provide any protection against intentionally modified data stream (malicious input).
209 Use this function in trusted environment only (data to decode comes from a trusted source).
211 LZ4LIB_API int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
214 LZ4_decompress_safe_partial() :
215 This function decompress a compressed block of size 'compressedSize' at position 'source'
216 into destination buffer 'dest' of size 'maxDecompressedSize'.
217 The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
218 reducing decompression time.
219 return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
220 Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
221 Always control how many bytes were decoded.
222 If the source stream is detected malformed, the function will stop decoding and return a negative result.
223 This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
225 LZ4LIB_API int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
228 /*-*********************************************
229 * Streaming Compression Functions
230 ***********************************************/
231 typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */
233 /*! LZ4_createStream() and LZ4_freeStream() :
234 * LZ4_createStream() will allocate and initialize an `LZ4_stream_t` structure.
235 * LZ4_freeStream() releases its memory.
237 LZ4LIB_API LZ4_stream_t* LZ4_createStream(void);
238 LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr);
240 /*! LZ4_resetStream() :
241 * An LZ4_stream_t structure can be allocated once and re-used multiple times.
242 * Use this function to init an allocated `LZ4_stream_t` structure and start a new compression.
244 LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr);
247 * Use this function to load a static dictionary into LZ4_stream.
248 * Any previous data will be forgotten, only 'dictionary' will remain in memory.
249 * Loading a size of 0 is allowed.
250 * Return : dictionary size, in bytes (necessarily <= 64 KB)
252 LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
254 /*! LZ4_compress_fast_continue() :
255 * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
256 * Important : Previous data blocks are assumed to still be present and unmodified !
257 * 'dst' buffer must be already allocated.
258 * If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
259 * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero.
261 LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration);
264 * If previously compressed data block is not guaranteed to remain available at its memory location,
265 * save it into a safer place (char* safeBuffer).
266 * Note : you don't need to call LZ4_loadDict() afterwards,
267 * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue().
268 * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
270 LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
273 /*-**********************************************
274 * Streaming Decompression Functions
275 * Bufferless synchronous API
276 ************************************************/
277 typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* incomplete type (defined later) */
279 /* creation / destruction of streaming decompression tracking structure */
280 LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void);
281 LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
283 /*! LZ4_setStreamDecode() :
284 * Use this function to instruct where to find the dictionary.
285 * Setting a size of 0 is allowed (same effect as reset).
286 * @return : 1 if OK, 0 if error
288 LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
291 LZ4_decompress_*_continue() :
292 These decoding functions allow decompression of multiple blocks in "streaming" mode.
293 Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
294 In the case of a ring buffers, decoding buffer must be either :
295 - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
296 In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
297 - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
298 maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
299 In which case, encoding and decoding buffers do not need to be synchronized,
300 and encoding ring buffer can have any size, including small ones ( < 64 KB).
301 - _At least_ 64 KB + 8 bytes + maxBlockSize.
302 In which case, encoding and decoding buffers do not need to be synchronized,
303 and encoding ring buffer can have any size, including larger than decoding buffer.
304 Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
305 and indicate where it is saved using LZ4_setStreamDecode()
307 LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
308 LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
311 /*! LZ4_decompress_*_usingDict() :
312 * These decoding functions work the same as
313 * a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue()
314 * They are stand-alone, and don't need an LZ4_streamDecode_t structure.
316 LZ4LIB_API int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
317 LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
320 /*^**********************************************
321 * !!!!!! STATIC LINKING ONLY !!!!!!
322 ***********************************************/
323 /*-************************************
324 * Private definitions
325 **************************************
326 * Do not use these definitions.
327 * They are exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`.
328 * Using these definitions will expose code to API and/or ABI break in future versions of the library.
329 **************************************/
330 #define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2)
331 #define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
332 #define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */
334 #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
338 uint32_t hashTable[LZ4_HASH_SIZE_U32];
339 uint32_t currentOffset;
341 const uint8_t* dictionary;
342 uint8_t* bufferStart; /* obsolete, used for slideInputBuffer */
344 } LZ4_stream_t_internal;
347 const uint8_t* externalDict;
349 const uint8_t* prefixEnd;
351 } LZ4_streamDecode_t_internal;
356 unsigned int hashTable[LZ4_HASH_SIZE_U32];
357 unsigned int currentOffset;
358 unsigned int initCheck;
359 const unsigned char* dictionary;
360 unsigned char* bufferStart; /* obsolete, used for slideInputBuffer */
361 unsigned int dictSize;
362 } LZ4_stream_t_internal;
365 const unsigned char* externalDict;
367 const unsigned char* prefixEnd;
369 } LZ4_streamDecode_t_internal;
375 * information structure to track an LZ4 stream.
376 * init this structure before first use.
377 * note : only use in association with static linking !
378 * this definition is not API/ABI safe,
379 * and may change in a future version !
381 #define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4)
382 #define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))
384 unsigned long long table[LZ4_STREAMSIZE_U64];
385 LZ4_stream_t_internal internal_donotuse;
386 } ; /* previously typedef'd to LZ4_stream_t */
390 * LZ4_streamDecode_t :
391 * information structure to track an LZ4 stream during decompression.
392 * init this structure using LZ4_setStreamDecode (or memset()) before first use
393 * note : only use in association with static linking !
394 * this definition is not API/ABI safe,
395 * and may change in a future version !
397 #define LZ4_STREAMDECODESIZE_U64 4
398 #define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
399 union LZ4_streamDecode_u {
400 unsigned long long table[LZ4_STREAMDECODESIZE_U64];
401 LZ4_streamDecode_t_internal internal_donotuse;
402 } ; /* previously typedef'd to LZ4_streamDecode_t */
405 /*=************************************
407 **************************************/
408 /* Deprecation warnings */
409 /* Should these warnings be a problem,
410 it is generally possible to disable them,
411 typically with -Wno-deprecated-declarations for gcc
412 or _CRT_SECURE_NO_WARNINGS in Visual.
413 Otherwise, it's also possible to define LZ4_DISABLE_DEPRECATE_WARNINGS */
414 #ifdef LZ4_DISABLE_DEPRECATE_WARNINGS
415 # define LZ4_DEPRECATED(message) /* disable deprecation warnings */
417 # define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
418 # if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
419 # define LZ4_DEPRECATED(message) [[deprecated(message)]]
420 # elif (LZ4_GCC_VERSION >= 405) || defined(__clang__)
421 # define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
422 # elif (LZ4_GCC_VERSION >= 301)
423 # define LZ4_DEPRECATED(message) __attribute__((deprecated))
424 # elif defined(_MSC_VER)
425 # define LZ4_DEPRECATED(message) __declspec(deprecated(message))
427 # pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler")
428 # define LZ4_DEPRECATED(message)
430 #endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */
432 /* Obsolete compression functions */
433 LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress (const char* source, char* dest, int sourceSize);
434 LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
435 LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
436 LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
437 LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
438 LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
440 /* Obsolete decompression functions */
441 /* These function names are completely deprecated and must no longer be used.
442 They are only provided in lz4.c for compatibility with older programs.
443 - LZ4_uncompress is the same as LZ4_decompress_fast
444 - LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
445 These function prototypes are now disabled; uncomment them only if you really need them.
446 It is highly recommended to stop using these prototypes and migrate to maintained ones */
447 /* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
448 /* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
450 /* Obsolete streaming functions; use new streaming interface whenever possible */
451 LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
452 LZ4_DEPRECATED("use LZ4_createStream() instead") int LZ4_sizeofStreamState(void);
453 LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void* state, char* inputBuffer);
454 LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state);
456 /* Obsolete streaming decoding functions */
457 LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
458 LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
461 #if defined (__cplusplus)
465 #endif /* LZ4_H_2983827168210 */
466 #endif /* SVN_INTERNAL_LZ4 */