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lz4.h
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1 /*
2  LZ4 - Fast LZ compression algorithm
3  Header File
4  Copyright (C) 2011-2015, Yann Collet.
5 
6  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
7 
8  Redistribution and use in source and binary forms, with or without
9  modification, are permitted provided that the following conditions are
10  met:
11 
12  * Redistributions of source code must retain the above copyright
13  notice, this list of conditions and the following disclaimer.
14  * Redistributions in binary form must reproduce the above
15  copyright notice, this list of conditions and the following disclaimer
16  in the documentation and/or other materials provided with the
17  distribution.
18 
19  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31  You can contact the author at :
32  - LZ4 source repository : https://github.com/Cyan4973/lz4
33  - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
34 */
35 #pragma once
36 
37 #if defined (__cplusplus)
38 extern "C" {
39 #endif
40 
41 /*
42  * lz4.h provides block compression functions, and gives full buffer control to programmer.
43  * If you need to generate inter-operable compressed data (respecting LZ4 frame specification),
44  * and can let the library handle its own memory, please use lz4frame.h instead.
45 */
46 
47 /**************************************
48 * Version
49 **************************************/
50 #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
51 #define LZ4_VERSION_MINOR 7 /* for new (non-breaking) interface capabilities */
52 #define LZ4_VERSION_RELEASE 1 /* for tweaks, bug-fixes, or development */
53 #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
54 int LZ4_versionNumber (void);
55 
56 /**************************************
57 * Tuning parameter
58 **************************************/
59 /*
60  * LZ4_MEMORY_USAGE :
61  * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
62  * Increasing memory usage improves compression ratio
63  * Reduced memory usage can improve speed, due to cache effect
64  * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
65  */
66 #define LZ4_MEMORY_USAGE 14
67 
68 
69 /**************************************
70 * Simple Functions
71 **************************************/
72 
73 int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize);
74 int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
75 
76 /*
77 LZ4_compress_default() :
78  Compresses 'sourceSize' bytes from buffer 'source'
79  into already allocated 'dest' buffer of size 'maxDestSize'.
80  Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize).
81  It also runs faster, so it's a recommended setting.
82  If the function cannot compress 'source' into a more limited 'dest' budget,
83  compression stops *immediately*, and the function result is zero.
84  As a consequence, 'dest' content is not valid.
85  This function never writes outside 'dest' buffer, nor read outside 'source' buffer.
86  sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE
87  maxDestSize : full or partial size of buffer 'dest' (which must be already allocated)
88  return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize)
89  or 0 if compression fails
90 
91 LZ4_decompress_safe() :
92  compressedSize : is the precise full size of the compressed block.
93  maxDecompressedSize : is the size of destination buffer, which must be already allocated.
94  return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize)
95  If destination buffer is not large enough, decoding will stop and output an error code (<0).
96  If the source stream is detected malformed, the function will stop decoding and return a negative result.
97  This function is protected against buffer overflow exploits, including malicious data packets.
98  It never writes outside output buffer, nor reads outside input buffer.
99 */
100 
101 
102 /**************************************
103 * Advanced Functions
104 **************************************/
105 #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
106 #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
107 
108 /*
109 LZ4_compressBound() :
110  Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
111  This function is primarily useful for memory allocation purposes (destination buffer size).
112  Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
113  Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize)
114  inputSize : max supported value is LZ4_MAX_INPUT_SIZE
115  return : maximum output size in a "worst case" scenario
116  or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
117 */
118 int LZ4_compressBound(int inputSize);
119 
120 /*
121 LZ4_compress_fast() :
122  Same as LZ4_compress_default(), but allows selecting an "acceleration" factor.
123  The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
124  It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
125  An acceleration value of "1" is the same as regular LZ4_compress_default()
126  Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1.
127 */
128 int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration);
129 
130 
131 /*
132 LZ4_compress_fast_extState() :
133  Same compression function, just using an externally allocated memory space to store compression state.
134  Use LZ4_sizeofState() to know how much memory must be allocated,
135  and allocate it on 8-bytes boundaries (using malloc() typically).
136  Then, provide it as 'void* state' to compression function.
137 */
138 int LZ4_sizeofState(void);
139 int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration);
140 
141 
142 /*
143 LZ4_compress_destSize() :
144  Reverse the logic, by compressing as much data as possible from 'source' buffer
145  into already allocated buffer 'dest' of size 'targetDestSize'.
146  This function either compresses the entire 'source' content into 'dest' if it's large enough,
147  or fill 'dest' buffer completely with as much data as possible from 'source'.
148  *sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'.
149  New value is necessarily <= old value.
150  return : Nb bytes written into 'dest' (necessarily <= targetDestSize)
151  or 0 if compression fails
152 */
153 int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize);
154 
155 
156 /*
157 LZ4_decompress_fast() :
158  originalSize : is the original and therefore uncompressed size
159  return : the number of bytes read from the source buffer (in other words, the compressed size)
160  If the source stream is detected malformed, the function will stop decoding and return a negative result.
161  Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
162  note : This function fully respect memory boundaries for properly formed compressed data.
163  It is a bit faster than LZ4_decompress_safe().
164  However, it does not provide any protection against intentionally modified data stream (malicious input).
165  Use this function in trusted environment only (data to decode comes from a trusted source).
166 */
167 int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
168 
169 /*
170 LZ4_decompress_safe_partial() :
171  This function decompress a compressed block of size 'compressedSize' at position 'source'
172  into destination buffer 'dest' of size 'maxDecompressedSize'.
173  The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
174  reducing decompression time.
175  return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
176  Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
177  Always control how many bytes were decoded.
178  If the source stream is detected malformed, the function will stop decoding and return a negative result.
179  This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
180 */
181 int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
182 
183 
184 /***********************************************
185 * Streaming Compression Functions
186 ***********************************************/
187 #define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4)
188 #define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(long long))
189 /*
190  * LZ4_stream_t
191  * information structure to track an LZ4 stream.
192  * important : init this structure content before first use !
193  * note : only allocated directly the structure if you are statically linking LZ4
194  * If you are using liblz4 as a DLL, please use below construction methods instead.
195  */
196 typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t;
197 
198 /*
199  * LZ4_resetStream
200  * Use this function to init an allocated LZ4_stream_t structure
201  */
202 void LZ4_resetStream (LZ4_stream_t* streamPtr);
203 
204 /*
205  * LZ4_createStream will allocate and initialize an LZ4_stream_t structure
206  * LZ4_freeStream releases its memory.
207  * In the context of a DLL (liblz4), please use these methods rather than the static struct.
208  * They are more future proof, in case of a change of LZ4_stream_t size.
209  */
211 int LZ4_freeStream (LZ4_stream_t* streamPtr);
212 
213 /*
214  * LZ4_loadDict
215  * Use this function to load a static dictionary into LZ4_stream.
216  * Any previous data will be forgotten, only 'dictionary' will remain in memory.
217  * Loading a size of 0 is allowed.
218  * Return : dictionary size, in bytes (necessarily <= 64 KB)
219  */
220 int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
221 
222 /*
223  * LZ4_compress_fast_continue
224  * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
225  * Important : Previous data blocks are assumed to still be present and unmodified !
226  * 'dst' buffer must be already allocated.
227  * If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
228  * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero.
229  */
230 int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration);
231 
232 /*
233  * LZ4_saveDict
234  * If previously compressed data block is not guaranteed to remain available at its memory location
235  * save it into a safer place (char* safeBuffer)
236  * Note : you don't need to call LZ4_loadDict() afterwards,
237  * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue()
238  * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error
239  */
240 int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
241 
242 
243 /************************************************
244 * Streaming Decompression Functions
245 ************************************************/
246 
247 #define LZ4_STREAMDECODESIZE_U64 4
248 #define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
249 typedef struct { unsigned long long table[LZ4_STREAMDECODESIZE_U64]; } LZ4_streamDecode_t;
250 /*
251  * LZ4_streamDecode_t
252  * information structure to track an LZ4 stream.
253  * init this structure content using LZ4_setStreamDecode or memset() before first use !
254  *
255  * In the context of a DLL (liblz4) please prefer usage of construction methods below.
256  * They are more future proof, in case of a change of LZ4_streamDecode_t size in the future.
257  * LZ4_createStreamDecode will allocate and initialize an LZ4_streamDecode_t structure
258  * LZ4_freeStreamDecode releases its memory.
259  */
261 int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
262 
263 /*
264  * LZ4_setStreamDecode
265  * Use this function to instruct where to find the dictionary.
266  * Setting a size of 0 is allowed (same effect as reset).
267  * Return : 1 if OK, 0 if error
268  */
269 int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
270 
271 /*
272 *_continue() :
273  These decoding functions allow decompression of multiple blocks in "streaming" mode.
274  Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
275  In the case of a ring buffers, decoding buffer must be either :
276  - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
277  In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
278  - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
279  maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
280  In which case, encoding and decoding buffers do not need to be synchronized,
281  and encoding ring buffer can have any size, including small ones ( < 64 KB).
282  - _At least_ 64 KB + 8 bytes + maxBlockSize.
283  In which case, encoding and decoding buffers do not need to be synchronized,
284  and encoding ring buffer can have any size, including larger than decoding buffer.
285  Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
286  and indicate where it is saved using LZ4_setStreamDecode()
287 */
288 int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
289 int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
290 
291 
292 /*
293 Advanced decoding functions :
294 *_usingDict() :
295  These decoding functions work the same as
296  a combination of LZ4_setStreamDecode() followed by LZ4_decompress_x_continue()
297  They are stand-alone. They don't need nor update an LZ4_streamDecode_t structure.
298 */
299 int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
300 int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
301 
302 
303 
304 /**************************************
305 * Obsolete Functions
306 **************************************/
307 /* Deprecate Warnings */
308 /* Should these warnings messages be a problem,
309  it is generally possible to disable them,
310  with -Wno-deprecated-declarations for gcc
311  or _CRT_SECURE_NO_WARNINGS in Visual for example.
312  You can also define LZ4_DEPRECATE_WARNING_DEFBLOCK. */
313 #ifndef LZ4_DEPRECATE_WARNING_DEFBLOCK
314 # define LZ4_DEPRECATE_WARNING_DEFBLOCK
315 # define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
316 # if (LZ4_GCC_VERSION >= 405) || defined(__clang__)
317 # define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
318 # elif (LZ4_GCC_VERSION >= 301)
319 # define LZ4_DEPRECATED(message) __attribute__((deprecated))
320 # elif defined(_MSC_VER)
321 # define LZ4_DEPRECATED(message) __declspec(deprecated(message))
322 # else
323 # pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler")
324 # define LZ4_DEPRECATED(message)
325 # endif
326 #endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */
327 
328 /* Obsolete compression functions */
329 /* These functions are planned to start generate warnings by r131 approximately */
330 int LZ4_compress (const char* source, char* dest, int sourceSize);
331 int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
332 int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
333 int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
334 int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
335 int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
336 
337 /* Obsolete decompression functions */
338 /* These function names are completely deprecated and must no longer be used.
339  They are only provided here for compatibility with older programs.
340  - LZ4_uncompress is the same as LZ4_decompress_fast
341  - LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
342  These function prototypes are now disabled; uncomment them only if you really need them.
343  It is highly recommended to stop using these prototypes and migrate to maintained ones */
344 /* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
345 /* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
346 
347 /* Obsolete streaming functions; use new streaming interface whenever possible */
348 LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
349 LZ4_DEPRECATED("use LZ4_createStream() instead") int LZ4_sizeofStreamState(void);
350 LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void* state, char* inputBuffer);
351 LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state);
352 
353 /* Obsolete streaming decoding functions */
356 
357 
358 #if defined (__cplusplus)
359 }
360 #endif
void * LZ4_create(char *inputBuffer)
Definition: lz4.c:1489
int LZ4_compress_destSize(const char *src, char *dst, int *srcSizePtr, int targetDstSize)
Definition: lz4.c:912
LZ4_stream_t * LZ4_createStream(void)
Definition: lz4.c:935
char * LZ4_slideInputBuffer(void *LZ4_Data)
Definition: lz4.c:1496
int LZ4_loadDict(LZ4_stream_t *LZ4_dict, const char *dictionary, int dictSize)
Definition: lz4.c:956
int LZ4_compress_limitedOutput(const char *source, char *dest, int inputSize, int maxOutputSize)
Definition: lz4.c:1455
int LZ4_decompress_fast(const char *source, char *dest, int originalSize)
Definition: lz4.c:1298
int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode, const char *dictionary, int dictSize)
Definition: lz4.c:1338
int LZ4_decompress_safe_partial(const char *source, char *dest, int compressedSize, int targetOutputSize, int maxDecompressedSize)
Definition: lz4.c:1293
int LZ4_resetStreamState(void *state, char *inputBuffer)
Definition: lz4.c:1482
#define LZ4_STREAMSIZE_U64
Definition: lz4.h:187
int LZ4_freeStreamDecode(LZ4_streamDecode_t *LZ4_stream)
Definition: lz4.c:1325
LZ4_streamDecode_t * LZ4_createStreamDecode(void)
Definition: lz4.c:1319
#define LZ4_STREAMDECODESIZE_U64
Definition: lz4.h:247
int LZ4_decompress_safe_withPrefix64k(const char *source, char *dest, int compressedSize, int maxOutputSize)
Definition: lz4.c:1505
char * dst
Definition: lz4.h:354
int LZ4_decompress_safe(const char *source, char *dest, int compressedSize, int maxDecompressedSize)
Definition: lz4.c:1288
int LZ4_compress_fast_extState(void *state, const char *source, char *dest, int inputSize, int maxOutputSize, int acceleration)
Definition: lz4.c:657
int LZ4_compress_default(const char *source, char *dest, int inputSize, int maxOutputSize)
Definition: lz4.c:697
char int int maxDstSize
Definition: lz4.h:354
int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode, const char *source, char *dest, int compressedSize, int maxOutputSize)
Definition: lz4.c:1355
int LZ4_decompress_fast_withPrefix64k(const char *source, char *dest, int originalSize)
Definition: lz4.c:1510
char int compressedSize
Definition: lz4.h:354
char * inputBuffer
Definition: lz4.h:350
int LZ4_decompress_safe_usingDict(const char *source, char *dest, int compressedSize, int maxOutputSize, const char *dictStart, int dictSize)
Definition: lz4.c:1434
int LZ4_compress_withState(void *state, const char *src, char *dst, int srcSize)
Definition: lz4.c:1458
char int originalSize
Definition: lz4.h:355
int LZ4_compress_fast(const char *source, char *dest, int inputSize, int maxOutputSize, int acceleration)
Definition: lz4.c:679
int LZ4_freeStream(LZ4_stream_t *LZ4_stream)
Definition: lz4.c:948
int LZ4_versionNumber(void)
Definition: lz4.c:371
void LZ4_resetStream(LZ4_stream_t *LZ4_stream)
Definition: lz4.c:943
#define LZ4_DEPRECATED(message)
Definition: lz4.h:324
int LZ4_sizeofState()
Definition: lz4.c:373
int LZ4_compress_continue(LZ4_stream_t *LZ4_stream, const char *source, char *dest, int inputSize)
Definition: lz4.c:1460
int LZ4_decompress_fast_usingDict(const char *source, char *dest, int originalSize, const char *dictStart, int dictSize)
Definition: lz4.c:1439
int LZ4_compress_limitedOutput_withState(void *state, const char *src, char *dst, int srcSize, int dstSize)
Definition: lz4.c:1457
int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode, const char *source, char *dest, int originalSize)
Definition: lz4.c:1384
int LZ4_sizeofStreamState()
Definition: lz4.c:1474
int LZ4_compress_limitedOutput_continue(LZ4_stream_t *LZ4_stream, const char *src, char *dst, int srcSize, int maxDstSize)
Definition: lz4.c:1459
int LZ4_compress(const char *source, char *dest, int inputSize)
Definition: lz4.c:1456
int LZ4_compressBound(int isize)
Definition: lz4.c:372
struct state state
Definition: parser.c:102
int LZ4_saveDict(LZ4_stream_t *LZ4_dict, char *safeBuffer, int dictSize)
Definition: lz4.c:1083
int LZ4_compress_fast_continue(LZ4_stream_t *LZ4_stream, const char *source, char *dest, int inputSize, int maxOutputSize, int acceleration)
Definition: lz4.c:1011