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1 /*
2    LZ4 HC - High Compression Mode of LZ4
3    Header File
4    Copyright (C) 2011-2017, Yann Collet.
5    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
6 
7    Redistribution and use in source and binary forms, with or without
8    modification, are permitted provided that the following conditions are
9    met:
10 
11        * Redistributions of source code must retain the above copyright
12    notice, this list of conditions and the following disclaimer.
13        * Redistributions in binary form must reproduce the above
14    copyright notice, this list of conditions and the following disclaimer
15    in the documentation and/or other materials provided with the
16    distribution.
17 
18    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 
30    You can contact the author at :
31    - LZ4 source repository : https://github.com/lz4/lz4
32    - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
33 */
34 #ifndef LZ4_HC_H_19834876238432
35 #define LZ4_HC_H_19834876238432
36 
37 #if defined (__cplusplus)
38 extern "C" {
39 #endif
40 
41 /* --- Dependency --- */
42 /* note : lz4hc requires lz4.h/lz4.c for compilation */
43 #include "lz4.h"   /* stddef, LZ4LIB_API, LZ4_DEPRECATED */
44 
45 
46 /* --- Useful constants --- */
47 #define LZ4HC_CLEVEL_MIN         3
48 #define LZ4HC_CLEVEL_DEFAULT     9
49 #define LZ4HC_CLEVEL_OPT_MIN    10
50 #define LZ4HC_CLEVEL_MAX        12
51 
52 
53 /*-************************************
54  *  Block Compression
55  **************************************/
56 /*! LZ4_compress_HC() :
57  *  Compress data from `src` into `dst`, using the more powerful but slower "HC" algorithm.
58  * `dst` must be already allocated.
59  *  Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h")
60  *  Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
61  * `compressionLevel` : any value between 1 and LZ4HC_CLEVEL_MAX will work.
62  *                      Values > LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX.
63  * @return : the number of bytes written into 'dst'
64  *           or 0 if compression fails.
65  */
66 LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel);
67 
68 
69 /* Note :
70  *   Decompression functions are provided within "lz4.h" (BSD license)
71  */
72 
73 
74 /*! LZ4_compress_HC_extStateHC() :
75  *  Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`.
76  * `state` size is provided by LZ4_sizeofStateHC().
77  *  Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly).
78  */
79 LZ4LIB_API int LZ4_sizeofStateHC(void);
80 LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
81 
82 
83 /*-************************************
84  *  Streaming Compression
85  *  Bufferless synchronous API
86  **************************************/
87  typedef union LZ4_streamHC_u LZ4_streamHC_t;   /* incomplete type (defined later) */
88 
89 /*! LZ4_createStreamHC() and LZ4_freeStreamHC() :
90  *  These functions create and release memory for LZ4 HC streaming state.
91  *  Newly created states are automatically initialized.
92  *  Existing states can be re-used several times, using LZ4_resetStreamHC().
93  *  These methods are API and ABI stable, they can be used in combination with a DLL.
94  */
95 LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void);
96 LZ4LIB_API int             LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
97 
98 LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
99 LZ4LIB_API int  LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize);
100 
101 LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize);
102 
103 LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize);
104 
105 /*
106   These functions compress data in successive blocks of any size, using previous blocks as dictionary.
107   One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks.
108   There is an exception for ring buffers, which can be smaller than 64 KB.
109   Ring buffers scenario is automatically detected and handled by LZ4_compress_HC_continue().
110 
111   Before starting compression, state must be properly initialized, using LZ4_resetStreamHC().
112   A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional).
113 
114   Then, use LZ4_compress_HC_continue() to compress each successive block.
115   Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression.
116   'dst' buffer should be sized to handle worst case scenarios (see LZ4_compressBound()), to ensure operation success.
117   Because in case of failure, the API does not guarantee context recovery, and context will have to be reset.
118   If `dst` buffer budget cannot be >= LZ4_compressBound(), consider using LZ4_compress_HC_continue_destSize() instead.
119 
120   If, for any reason, previous data block can't be preserved unmodified in memory for next compression block,
121   you can save it to a more stable memory space, using LZ4_saveDictHC().
122   Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer'.
123 */
124 
125 
126 /*-**************************************************************
127  * PRIVATE DEFINITIONS :
128  * Do not use these definitions.
129  * They are exposed to allow static allocation of `LZ4_streamHC_t`.
130  * Using these definitions makes the code vulnerable to potential API break when upgrading LZ4
131  ****************************************************************/
132 #define LZ4HC_DICTIONARY_LOGSIZE 16
133 #define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE)
134 #define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1)
135 
136 #define LZ4HC_HASH_LOG 15
137 #define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG)
138 #define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1)
139 
140 
141 #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
142 #include <stdint.h>
143 
144 typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal;
145 struct LZ4HC_CCtx_internal
146 {
147     uint32_t   hashTable[LZ4HC_HASHTABLESIZE];
148     uint16_t   chainTable[LZ4HC_MAXD];
149     const uint8_t* end;         /* next block here to continue on current prefix */
150     const uint8_t* base;        /* All index relative to this position */
151     const uint8_t* dictBase;    /* alternate base for extDict */
152     uint32_t   dictLimit;       /* below that point, need extDict */
153     uint32_t   lowLimit;        /* below that point, no more dict */
154     uint32_t   nextToUpdate;    /* index from which to continue dictionary update */
155     short      compressionLevel;
156     short      favorDecSpeed;
157     const LZ4HC_CCtx_internal* dictCtx;
158 };
159 
160 #else
161 
162 typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal;
163 struct LZ4HC_CCtx_internal
164 {
165     unsigned int   hashTable[LZ4HC_HASHTABLESIZE];
166     unsigned short chainTable[LZ4HC_MAXD];
167     const unsigned char* end;        /* next block here to continue on current prefix */
168     const unsigned char* base;       /* All index relative to this position */
169     const unsigned char* dictBase;   /* alternate base for extDict */
170     unsigned int   dictLimit;        /* below that point, need extDict */
171     unsigned int   lowLimit;         /* below that point, no more dict */
172     unsigned int   nextToUpdate;     /* index from which to continue dictionary update */
173     short          compressionLevel;
174     short          favorDecSpeed;
175     const LZ4HC_CCtx_internal* dictCtx;
176 };
177 
178 #endif
179 
180 #define LZ4_STREAMHCSIZE       (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56) /* 262200 */
181 #define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
182 union LZ4_streamHC_u {
183     size_t table[LZ4_STREAMHCSIZE_SIZET];
184     LZ4HC_CCtx_internal internal_donotuse;
185 };   /* previously typedef'd to LZ4_streamHC_t */
186 /*
187   LZ4_streamHC_t :
188   This structure allows static allocation of LZ4 HC streaming state.
189   State must be initialized using LZ4_resetStreamHC() before first use.
190 
191   Static allocation shall only be used in combination with static linking.
192   When invoking LZ4 from a DLL, use create/free functions instead, which are API and ABI stable.
193 */
194 
195 
196 /*-************************************
197 *  Deprecated Functions
198 **************************************/
199 /* see lz4.h LZ4_DISABLE_DEPRECATE_WARNINGS to turn off deprecation warnings */
200 
201 /* deprecated compression functions */
202 LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC               (const char* source, char* dest, int inputSize);
203 LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
204 LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
205 LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
206 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_withStateHC               (void* state, const char* source, char* dest, int inputSize);
207 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
208 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
209 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
210 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_continue               (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
211 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
212 
213 /* Obsolete streaming functions; degraded functionality; do not use!
214  *
215  * In order to perform streaming compression, these functions depended on data
216  * that is no longer tracked in the state. They have been preserved as well as
217  * possible: using them will still produce a correct output. However, use of
218  * LZ4_slideInputBufferHC() will truncate the history of the stream, rather
219  * than preserve a window-sized chunk of history.
220  */
221 LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API void* LZ4_createHC (const char* inputBuffer);
222 LZ4_DEPRECATED("use LZ4_saveDictHC() instead") LZ4LIB_API     char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
223 LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") LZ4LIB_API   int   LZ4_freeHC (void* LZ4HC_Data);
224 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
225 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
226 LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API int   LZ4_sizeofStreamStateHC(void);
227 LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") LZ4LIB_API  int   LZ4_resetStreamStateHC(void* state, char* inputBuffer);
228 
229 
230 #if defined (__cplusplus)
231 }
232 #endif
233 
234 #endif /* LZ4_HC_H_19834876238432 */
235 
236 
237 /*-**************************************************
238  * !!!!!     STATIC LINKING ONLY     !!!!!
239  * Following definitions are considered experimental.
240  * They should not be linked from DLL,
241  * as there is no guarantee of API stability yet.
242  * Prototypes will be promoted to "stable" status
243  * after successfull usage in real-life scenarios.
244  ***************************************************/
245 #ifdef LZ4_HC_STATIC_LINKING_ONLY   /* protection macro */
246 #ifndef LZ4_HC_SLO_098092834
247 #define LZ4_HC_SLO_098092834
248 
249 #if defined (__cplusplus)
250 extern "C" {
251 #endif
252 
253 /*! LZ4_compress_HC_destSize() : v1.8.0 (experimental)
254  *  Will try to compress as much data from `src` as possible
255  *  that can fit into `targetDstSize` budget.
256  *  Result is provided in 2 parts :
257  * @return : the number of bytes written into 'dst'
258  *           or 0 if compression fails.
259  * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`
260  */
261 int LZ4_compress_HC_destSize(void* LZ4HC_Data,
262                              const char* src, char* dst,
263                              int* srcSizePtr, int targetDstSize,
264                              int compressionLevel);
265 
266 /*! LZ4_compress_HC_continue_destSize() : v1.8.0 (experimental)
267  *  Similar as LZ4_compress_HC_continue(),
268  *  but will read a variable nb of bytes from `src`
269  *  to fit into `targetDstSize` budget.
270  *  Result is provided in 2 parts :
271  * @return : the number of bytes written into 'dst'
272  *           or 0 if compression fails.
273  * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`.
274  */
275 int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr,
276                             const char* src, char* dst,
277                             int* srcSizePtr, int targetDstSize);
278 
279 /*! LZ4_setCompressionLevel() : v1.8.0 (experimental)
280  *  It's possible to change compression level between 2 invocations of LZ4_compress_HC_continue*()
281  */
282 void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
283 
284 /*! LZ4_favorDecompressionSpeed() : v1.8.2 (experimental)
285  *  Parser will select decisions favoring decompression over compression ratio.
286  *  Only work at highest compression settings (level >= LZ4HC_CLEVEL_OPT_MIN)
287  */
288 void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor);
289 
290 /*! LZ4_resetStreamHC_fast() :
291  *  When an LZ4_streamHC_t is known to be in a internally coherent state,
292  *  it can often be prepared for a new compression with almost no work, only
293  *  sometimes falling back to the full, expensive reset that is always required
294  *  when the stream is in an indeterminate state (i.e., the reset performed by
295  *  LZ4_resetStreamHC()).
296  *
297  *  LZ4_streamHCs are guaranteed to be in a valid state when:
298  *  - returned from LZ4_createStreamHC()
299  *  - reset by LZ4_resetStreamHC()
300  *  - memset(stream, 0, sizeof(LZ4_streamHC_t))
301  *  - the stream was in a valid state and was reset by LZ4_resetStreamHC_fast()
302  *  - the stream was in a valid state and was then used in any compression call
303  *    that returned success
304  *  - the stream was in an indeterminate state and was used in a compression
305  *    call that fully reset the state (LZ4_compress_HC_extStateHC()) and that
306  *    returned success
307  */
308 void LZ4_resetStreamHC_fast(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
309 
310 /*! LZ4_compress_HC_extStateHC_fastReset() :
311  *  A variant of LZ4_compress_HC_extStateHC().
312  *
313  *  Using this variant avoids an expensive initialization step. It is only safe
314  *  to call if the state buffer is known to be correctly initialized already
315  *  (see above comment on LZ4_resetStreamHC_fast() for a definition of
316  *  "correctly initialized"). From a high level, the difference is that this
317  *  function initializes the provided state with a call to
318  *  LZ4_resetStreamHC_fast() while LZ4_compress_HC_extStateHC() starts with a
319  *  call to LZ4_resetStreamHC().
320  */
321 int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel);
322 
323 /*! LZ4_attach_HC_dictionary() :
324  *  This is an experimental API that allows for the efficient use of a
325  *  static dictionary many times.
326  *
327  *  Rather than re-loading the dictionary buffer into a working context before
328  *  each compression, or copying a pre-loaded dictionary's LZ4_streamHC_t into a
329  *  working LZ4_streamHC_t, this function introduces a no-copy setup mechanism,
330  *  in which the working stream references the dictionary stream in-place.
331  *
332  *  Several assumptions are made about the state of the dictionary stream.
333  *  Currently, only streams which have been prepared by LZ4_loadDictHC() should
334  *  be expected to work.
335  *
336  *  Alternatively, the provided dictionary stream pointer may be NULL, in which
337  *  case any existing dictionary stream is unset.
338  *
339  *  A dictionary should only be attached to a stream without any history (i.e.,
340  *  a stream that has just been reset).
341  *
342  *  The dictionary will remain attached to the working stream only for the
343  *  current stream session. Calls to LZ4_resetStreamHC(_fast) will remove the
344  *  dictionary context association from the working stream. The dictionary
345  *  stream (and source buffer) must remain in-place / accessible / unchanged
346  *  through the lifetime of the stream session.
347  */
348 LZ4LIB_API void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream);
349 
350 #if defined (__cplusplus)
351 }
352 #endif
353 
354 #endif   /* LZ4_HC_SLO_098092834 */
355 #endif   /* LZ4_HC_STATIC_LINKING_ONLY */
356