lz4.h
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00001 /*
00002    LZ4 - Fast LZ compression algorithm
00003    Header File
00004    Copyright (C) 2011-2015, Yann Collet.
00005 
00006    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
00007 
00008    Redistribution and use in source and binary forms, with or without
00009    modification, are permitted provided that the following conditions are
00010    met:
00011 
00012        * Redistributions of source code must retain the above copyright
00013    notice, this list of conditions and the following disclaimer.
00014        * Redistributions in binary form must reproduce the above
00015    copyright notice, this list of conditions and the following disclaimer
00016    in the documentation and/or other materials provided with the
00017    distribution.
00018 
00019    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00020    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00021    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00022    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
00023    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00024    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00025    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00026    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00027    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00028    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00029    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00030 
00031    You can contact the author at :
00032    - LZ4 source repository : https://github.com/Cyan4973/lz4
00033    - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
00034 */
00035 #pragma once
00036 
00037 #if defined (__cplusplus)
00038 extern "C" {
00039 #endif
00040 
00041 /*
00042  * lz4.h provides block compression functions, and gives full buffer control to programmer.
00043  * If you need to generate inter-operable compressed data (respecting LZ4 frame specification),
00044  * and can let the library handle its own memory, please use lz4frame.h instead.
00045 */
00046 
00047 /**************************************
00048 *  Version
00049 **************************************/
00050 #define LZ4_VERSION_MAJOR    1    /* for breaking interface changes  */
00051 #define LZ4_VERSION_MINOR    7    /* for new (non-breaking) interface capabilities */
00052 #define LZ4_VERSION_RELEASE  1    /* for tweaks, bug-fixes, or development */
00053 #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
00054 int LZ4_versionNumber (void);
00055 
00056 /**************************************
00057 *  Tuning parameter
00058 **************************************/
00059 /*
00060  * LZ4_MEMORY_USAGE :
00061  * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
00062  * Increasing memory usage improves compression ratio
00063  * Reduced memory usage can improve speed, due to cache effect
00064  * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
00065  */
00066 #define LZ4_MEMORY_USAGE 14
00067 
00068 
00069 /**************************************
00070 *  Simple Functions
00071 **************************************/
00072 
00073 int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize);
00074 int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
00075 
00076 /*
00077 LZ4_compress_default() :
00078     Compresses 'sourceSize' bytes from buffer 'source'
00079     into already allocated 'dest' buffer of size 'maxDestSize'.
00080     Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize).
00081     It also runs faster, so it's a recommended setting.
00082     If the function cannot compress 'source' into a more limited 'dest' budget,
00083     compression stops *immediately*, and the function result is zero.
00084     As a consequence, 'dest' content is not valid.
00085     This function never writes outside 'dest' buffer, nor read outside 'source' buffer.
00086         sourceSize  : Max supported value is LZ4_MAX_INPUT_VALUE
00087         maxDestSize : full or partial size of buffer 'dest' (which must be already allocated)
00088         return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize)
00089               or 0 if compression fails
00090 
00091 LZ4_decompress_safe() :
00092     compressedSize : is the precise full size of the compressed block.
00093     maxDecompressedSize : is the size of destination buffer, which must be already allocated.
00094     return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize)
00095              If destination buffer is not large enough, decoding will stop and output an error code (<0).
00096              If the source stream is detected malformed, the function will stop decoding and return a negative result.
00097              This function is protected against buffer overflow exploits, including malicious data packets.
00098              It never writes outside output buffer, nor reads outside input buffer.
00099 */
00100 
00101 
00102 /**************************************
00103 *  Advanced Functions
00104 **************************************/
00105 #define LZ4_MAX_INPUT_SIZE        0x7E000000   /* 2 113 929 216 bytes */
00106 #define LZ4_COMPRESSBOUND(isize)  ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
00107 
00108 /*
00109 LZ4_compressBound() :
00110     Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
00111     This function is primarily useful for memory allocation purposes (destination buffer size).
00112     Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
00113     Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize)
00114         inputSize  : max supported value is LZ4_MAX_INPUT_SIZE
00115         return : maximum output size in a "worst case" scenario
00116               or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
00117 */
00118 int LZ4_compressBound(int inputSize);
00119 
00120 /*
00121 LZ4_compress_fast() :
00122     Same as LZ4_compress_default(), but allows to select an "acceleration" factor.
00123     The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
00124     It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
00125     An acceleration value of "1" is the same as regular LZ4_compress_default()
00126     Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1.
00127 */
00128 int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration);
00129 
00130 
00131 /*
00132 LZ4_compress_fast_extState() :
00133     Same compression function, just using an externally allocated memory space to store compression state.
00134     Use LZ4_sizeofState() to know how much memory must be allocated,
00135     and allocate it on 8-bytes boundaries (using malloc() typically).
00136     Then, provide it as 'void* state' to compression function.
00137 */
00138 int LZ4_sizeofState(void);
00139 int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration);
00140 
00141 
00142 /*
00143 LZ4_compress_destSize() :
00144     Reverse the logic, by compressing as much data as possible from 'source' buffer
00145     into already allocated buffer 'dest' of size 'targetDestSize'.
00146     This function either compresses the entire 'source' content into 'dest' if it's large enough,
00147     or fill 'dest' buffer completely with as much data as possible from 'source'.
00148         *sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'.
00149                          New value is necessarily <= old value.
00150         return : Nb bytes written into 'dest' (necessarily <= targetDestSize)
00151               or 0 if compression fails
00152 */
00153 int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize);
00154 
00155 
00156 /*
00157 LZ4_decompress_fast() :
00158     originalSize : is the original and therefore uncompressed size
00159     return : the number of bytes read from the source buffer (in other words, the compressed size)
00160              If the source stream is detected malformed, the function will stop decoding and return a negative result.
00161              Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
00162     note : This function fully respect memory boundaries for properly formed compressed data.
00163            It is a bit faster than LZ4_decompress_safe().
00164            However, it does not provide any protection against intentionally modified data stream (malicious input).
00165            Use this function in trusted environment only (data to decode comes from a trusted source).
00166 */
00167 int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
00168 
00169 /*
00170 LZ4_decompress_safe_partial() :
00171     This function decompress a compressed block of size 'compressedSize' at position 'source'
00172     into destination buffer 'dest' of size 'maxDecompressedSize'.
00173     The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
00174     reducing decompression time.
00175     return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
00176        Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
00177              Always control how many bytes were decoded.
00178              If the source stream is detected malformed, the function will stop decoding and return a negative result.
00179              This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
00180 */
00181 int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
00182 
00183 
00184 /***********************************************
00185 *  Streaming Compression Functions
00186 ***********************************************/
00187 #define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4)
00188 #define LZ4_STREAMSIZE     (LZ4_STREAMSIZE_U64 * sizeof(long long))
00189 /*
00190  * LZ4_stream_t
00191  * information structure to track an LZ4 stream.
00192  * important : init this structure content before first use !
00193  * note : only allocated directly the structure if you are statically linking LZ4
00194  *        If you are using liblz4 as a DLL, please use below construction methods instead.
00195  */
00196 typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t;
00197 
00198 /*
00199  * LZ4_resetStream
00200  * Use this function to init an allocated LZ4_stream_t structure
00201  */
00202 void LZ4_resetStream (LZ4_stream_t* streamPtr);
00203 
00204 /*
00205  * LZ4_createStream will allocate and initialize an LZ4_stream_t structure
00206  * LZ4_freeStream releases its memory.
00207  * In the context of a DLL (liblz4), please use these methods rather than the static struct.
00208  * They are more future proof, in case of a change of LZ4_stream_t size.
00209  */
00210 LZ4_stream_t* LZ4_createStream(void);
00211 int           LZ4_freeStream (LZ4_stream_t* streamPtr);
00212 
00213 /*
00214  * LZ4_loadDict
00215  * Use this function to load a static dictionary into LZ4_stream.
00216  * Any previous data will be forgotten, only 'dictionary' will remain in memory.
00217  * Loading a size of 0 is allowed.
00218  * Return : dictionary size, in bytes (necessarily <= 64 KB)
00219  */
00220 int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
00221 
00222 /*
00223  * LZ4_compress_fast_continue
00224  * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
00225  * Important : Previous data blocks are assumed to still be present and unmodified !
00226  * 'dst' buffer must be already allocated.
00227  * If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
00228  * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero.
00229  */
00230 int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration);
00231 
00232 /*
00233  * LZ4_saveDict
00234  * If previously compressed data block is not guaranteed to remain available at its memory location
00235  * save it into a safer place (char* safeBuffer)
00236  * Note : you don't need to call LZ4_loadDict() afterwards,
00237  *        dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue()
00238  * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error
00239  */
00240 int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
00241 
00242 
00243 /************************************************
00244 *  Streaming Decompression Functions
00245 ************************************************/
00246 
00247 #define LZ4_STREAMDECODESIZE_U64  4
00248 #define LZ4_STREAMDECODESIZE     (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
00249 typedef struct { unsigned long long table[LZ4_STREAMDECODESIZE_U64]; } LZ4_streamDecode_t;
00250 /*
00251  * LZ4_streamDecode_t
00252  * information structure to track an LZ4 stream.
00253  * init this structure content using LZ4_setStreamDecode or memset() before first use !
00254  *
00255  * In the context of a DLL (liblz4) please prefer usage of construction methods below.
00256  * They are more future proof, in case of a change of LZ4_streamDecode_t size in the future.
00257  * LZ4_createStreamDecode will allocate and initialize an LZ4_streamDecode_t structure
00258  * LZ4_freeStreamDecode releases its memory.
00259  */
00260 LZ4_streamDecode_t* LZ4_createStreamDecode(void);
00261 int                 LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
00262 
00263 /*
00264  * LZ4_setStreamDecode
00265  * Use this function to instruct where to find the dictionary.
00266  * Setting a size of 0 is allowed (same effect as reset).
00267  * Return : 1 if OK, 0 if error
00268  */
00269 int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
00270 
00271 /*
00272 *_continue() :
00273     These decoding functions allow decompression of multiple blocks in "streaming" mode.
00274     Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
00275     In the case of a ring buffers, decoding buffer must be either :
00276     - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
00277       In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
00278     - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
00279       maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
00280       In which case, encoding and decoding buffers do not need to be synchronized,
00281       and encoding ring buffer can have any size, including small ones ( < 64 KB).
00282     - _At least_ 64 KB + 8 bytes + maxBlockSize.
00283       In which case, encoding and decoding buffers do not need to be synchronized,
00284       and encoding ring buffer can have any size, including larger than decoding buffer.
00285     Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
00286     and indicate where it is saved using LZ4_setStreamDecode()
00287 */
00288 int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
00289 int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
00290 
00291 
00292 /*
00293 Advanced decoding functions :
00294 *_usingDict() :
00295     These decoding functions work the same as
00296     a combination of LZ4_setStreamDecode() followed by LZ4_decompress_x_continue()
00297     They are stand-alone. They don't need nor update an LZ4_streamDecode_t structure.
00298 */
00299 int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
00300 int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
00301 
00302 
00303 
00304 /**************************************
00305 *  Obsolete Functions
00306 **************************************/
00307 /* Deprecate Warnings */
00308 /* Should these warnings messages be a problem,
00309    it is generally possible to disable them,
00310    with -Wno-deprecated-declarations for gcc
00311    or _CRT_SECURE_NO_WARNINGS in Visual for example.
00312    You can also define LZ4_DEPRECATE_WARNING_DEFBLOCK. */
00313 #ifndef LZ4_DEPRECATE_WARNING_DEFBLOCK
00314 #  define LZ4_DEPRECATE_WARNING_DEFBLOCK
00315 #  define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
00316 #  if (LZ4_GCC_VERSION >= 405) || defined(__clang__)
00317 #    define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
00318 #  elif (LZ4_GCC_VERSION >= 301)
00319 #    define LZ4_DEPRECATED(message) __attribute__((deprecated))
00320 #  elif defined(_MSC_VER)
00321 #    define LZ4_DEPRECATED(message) __declspec(deprecated(message))
00322 #  else
00323 #    pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler")
00324 #    define LZ4_DEPRECATED(message)
00325 #  endif
00326 #endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */
00327 
00328 /* Obsolete compression functions */
00329 /* These functions are planned to start generate warnings by r131 approximately */
00330 int LZ4_compress               (const char* source, char* dest, int sourceSize);
00331 int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
00332 int LZ4_compress_withState               (void* state, const char* source, char* dest, int inputSize);
00333 int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
00334 int LZ4_compress_continue                (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
00335 int LZ4_compress_limitedOutput_continue  (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
00336 
00337 /* Obsolete decompression functions */
00338 /* These function names are completely deprecated and must no longer be used.
00339    They are only provided here for compatibility with older programs.
00340     - LZ4_uncompress is the same as LZ4_decompress_fast
00341     - LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
00342    These function prototypes are now disabled; uncomment them only if you really need them.
00343    It is highly recommended to stop using these prototypes and migrate to maintained ones */
00344 /* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
00345 /* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
00346 
00347 /* Obsolete streaming functions; use new streaming interface whenever possible */
00348 LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
00349 LZ4_DEPRECATED("use LZ4_createStream() instead") int   LZ4_sizeofStreamState(void);
00350 LZ4_DEPRECATED("use LZ4_resetStream() instead")  int   LZ4_resetStreamState(void* state, char* inputBuffer);
00351 LZ4_DEPRECATED("use LZ4_saveDict() instead")     char* LZ4_slideInputBuffer (void* state);
00352 
00353 /* Obsolete streaming decoding functions */
00354 LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
00355 LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
00356 
00357 
00358 #if defined (__cplusplus)
00359 }
00360 #endif


rtabmap
Author(s): Mathieu Labbe
autogenerated on Sat Jul 23 2016 11:44:16