xref: /freebsd/sys/contrib/openzfs/module/zstd/lib/common/huf.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /* ******************************************************************
2  * huff0 huffman codec,
3  * part of Finite State Entropy library
4  * Copyright (c) 2013-2020, Yann Collet, Facebook, Inc.
5  *
6  * You can contact the author at :
7  * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
8  *
9  * This source code is licensed under both the BSD-style license (found in the
10  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
11  * in the COPYING file in the root directory of this source tree).
12  * You may select, at your option, one of the above-listed licenses.
13 ****************************************************************** */
14 
15 #if defined (__cplusplus)
16 extern "C" {
17 #endif
18 
19 #ifndef HUF_H_298734234
20 #define HUF_H_298734234
21 
22 /* *** Dependencies *** */
23 #include <stddef.h>    /* size_t */
24 
25 
26 /* *** library symbols visibility *** */
27 /* Note : when linking with -fvisibility=hidden on gcc, or by default on Visual,
28  *        HUF symbols remain "private" (internal symbols for library only).
29  *        Set macro FSE_DLL_EXPORT to 1 if you want HUF symbols visible on DLL interface */
30 #if defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1) && defined(__GNUC__) && (__GNUC__ >= 4)
31 #  define HUF_PUBLIC_API __attribute__ ((visibility ("default")))
32 #elif defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1)   /* Visual expected */
33 #  define HUF_PUBLIC_API __declspec(dllexport)
34 #elif defined(FSE_DLL_IMPORT) && (FSE_DLL_IMPORT==1)
35 #  define HUF_PUBLIC_API __declspec(dllimport)  /* not required, just to generate faster code (saves a function pointer load from IAT and an indirect jump) */
36 #else
37 #  define HUF_PUBLIC_API
38 #endif
39 
40 
41 /* ========================== */
42 /* ***  simple functions  *** */
43 /* ========================== */
44 
45 /** HUF_compress() :
46  *  Compress content from buffer 'src', of size 'srcSize', into buffer 'dst'.
47  * 'dst' buffer must be already allocated.
48  *  Compression runs faster if `dstCapacity` >= HUF_compressBound(srcSize).
49  * `srcSize` must be <= `HUF_BLOCKSIZE_MAX` == 128 KB.
50  * @return : size of compressed data (<= `dstCapacity`).
51  *  Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
52  *                   if HUF_isError(return), compression failed (more details using HUF_getErrorName())
53  */
54 HUF_PUBLIC_API size_t HUF_compress(void* dst, size_t dstCapacity,
55                              const void* src, size_t srcSize);
56 
57 /** HUF_decompress() :
58  *  Decompress HUF data from buffer 'cSrc', of size 'cSrcSize',
59  *  into already allocated buffer 'dst', of minimum size 'dstSize'.
60  * `originalSize` : **must** be the ***exact*** size of original (uncompressed) data.
61  *  Note : in contrast with FSE, HUF_decompress can regenerate
62  *         RLE (cSrcSize==1) and uncompressed (cSrcSize==dstSize) data,
63  *         because it knows size to regenerate (originalSize).
64  * @return : size of regenerated data (== originalSize),
65  *           or an error code, which can be tested using HUF_isError()
66  */
67 HUF_PUBLIC_API size_t HUF_decompress(void* dst,  size_t originalSize,
68                                const void* cSrc, size_t cSrcSize);
69 
70 
71 /* ***   Tool functions *** */
72 #define HUF_BLOCKSIZE_MAX (128 * 1024)                  /**< maximum input size for a single block compressed with HUF_compress */
73 HUF_PUBLIC_API size_t HUF_compressBound(size_t size);   /**< maximum compressed size (worst case) */
74 
75 /* Error Management */
76 HUF_PUBLIC_API unsigned    HUF_isError(size_t code);       /**< tells if a return value is an error code */
77 HUF_PUBLIC_API const char* HUF_getErrorName(size_t code);  /**< provides error code string (useful for debugging) */
78 
79 
80 /* ***   Advanced function   *** */
81 
82 /** HUF_compress2() :
83  *  Same as HUF_compress(), but offers control over `maxSymbolValue` and `tableLog`.
84  * `maxSymbolValue` must be <= HUF_SYMBOLVALUE_MAX .
85  * `tableLog` must be `<= HUF_TABLELOG_MAX` . */
86 HUF_PUBLIC_API size_t HUF_compress2 (void* dst, size_t dstCapacity,
87                                const void* src, size_t srcSize,
88                                unsigned maxSymbolValue, unsigned tableLog);
89 
90 /** HUF_compress4X_wksp() :
91  *  Same as HUF_compress2(), but uses externally allocated `workSpace`.
92  * `workspace` must have minimum alignment of 4, and be at least as large as HUF_WORKSPACE_SIZE */
93 #define HUF_WORKSPACE_SIZE ((6 << 10) + 256)
94 #define HUF_WORKSPACE_SIZE_U32 (HUF_WORKSPACE_SIZE / sizeof(U32))
95 HUF_PUBLIC_API size_t HUF_compress4X_wksp (void* dst, size_t dstCapacity,
96                                      const void* src, size_t srcSize,
97                                      unsigned maxSymbolValue, unsigned tableLog,
98                                      void* workSpace, size_t wkspSize);
99 
100 #endif   /* HUF_H_298734234 */
101 
102 /* ******************************************************************
103  *  WARNING !!
104  *  The following section contains advanced and experimental definitions
105  *  which shall never be used in the context of a dynamic library,
106  *  because they are not guaranteed to remain stable in the future.
107  *  Only consider them in association with static linking.
108  * *****************************************************************/
109 #if defined(HUF_STATIC_LINKING_ONLY) && !defined(HUF_H_HUF_STATIC_LINKING_ONLY)
110 #define HUF_H_HUF_STATIC_LINKING_ONLY
111 
112 /* *** Dependencies *** */
113 #include "mem.h"   /* U32 */
114 
115 
116 /* *** Constants *** */
117 #define HUF_TABLELOG_MAX      12      /* max runtime value of tableLog (due to static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
118 #define HUF_TABLELOG_DEFAULT  11      /* default tableLog value when none specified */
119 #define HUF_SYMBOLVALUE_MAX  255
120 
121 #define HUF_TABLELOG_ABSOLUTEMAX  15  /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
122 #if (HUF_TABLELOG_MAX > HUF_TABLELOG_ABSOLUTEMAX)
123 #  error "HUF_TABLELOG_MAX is too large !"
124 #endif
125 
126 
127 /* ****************************************
128 *  Static allocation
129 ******************************************/
130 /* HUF buffer bounds */
131 #define HUF_CTABLEBOUND 129
132 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true when incompressible is pre-filtered with fast heuristic */
133 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
134 
135 /* static allocation of HUF's Compression Table */
136 #define HUF_CTABLE_SIZE_U32(maxSymbolValue)   ((maxSymbolValue)+1)   /* Use tables of U32, for proper alignment */
137 #define HUF_CTABLE_SIZE(maxSymbolValue)       (HUF_CTABLE_SIZE_U32(maxSymbolValue) * sizeof(U32))
138 #define HUF_CREATE_STATIC_CTABLE(name, maxSymbolValue) \
139     U32 name##hb[HUF_CTABLE_SIZE_U32(maxSymbolValue)]; \
140     void* name##hv = &(name##hb); \
141     HUF_CElt* name = (HUF_CElt*)(name##hv)   /* no final ; */
142 
143 /* static allocation of HUF's DTable */
144 typedef U32 HUF_DTable;
145 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<(maxTableLog)))
146 #define HUF_CREATE_STATIC_DTABLEX1(DTable, maxTableLog) \
147         HUF_DTable DTable[HUF_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1) * 0x01000001) }
148 #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
149         HUF_DTable DTable[HUF_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog) * 0x01000001) }
150 
151 
152 /* ****************************************
153 *  Advanced decompression functions
154 ******************************************/
155 size_t HUF_decompress4X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
156 #ifndef HUF_FORCE_DECOMPRESS_X1
157 size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
158 #endif
159 
160 size_t HUF_decompress4X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< decodes RLE and uncompressed */
161 size_t HUF_decompress4X_hufOnly(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< considers RLE and uncompressed as errors */
162 size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize); /**< considers RLE and uncompressed as errors */
163 size_t HUF_decompress4X1_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
164 size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< single-symbol decoder */
165 #ifndef HUF_FORCE_DECOMPRESS_X1
166 size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
167 size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< double-symbols decoder */
168 #endif
169 
170 
171 /* ****************************************
172  *  HUF detailed API
173  * ****************************************/
174 
175 /*! HUF_compress() does the following:
176  *  1. count symbol occurrence from source[] into table count[] using FSE_count() (exposed within "fse.h")
177  *  2. (optional) refine tableLog using HUF_optimalTableLog()
178  *  3. build Huffman table from count using HUF_buildCTable()
179  *  4. save Huffman table to memory buffer using HUF_writeCTable()
180  *  5. encode the data stream using HUF_compress4X_usingCTable()
181  *
182  *  The following API allows targeting specific sub-functions for advanced tasks.
183  *  For example, it's possible to compress several blocks using the same 'CTable',
184  *  or to save and regenerate 'CTable' using external methods.
185  */
186 unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);
187 typedef struct HUF_CElt_s HUF_CElt;   /* incomplete type */
188 size_t HUF_buildCTable (HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue, unsigned maxNbBits);   /* @return : maxNbBits; CTable and count can overlap. In which case, CTable will overwrite count content */
189 size_t HUF_writeCTable (void* dst, size_t maxDstSize, const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog);
190 size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
191 size_t HUF_estimateCompressedSize(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue);
192 int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue);
193 
194 typedef enum {
195    HUF_repeat_none,  /**< Cannot use the previous table */
196    HUF_repeat_check, /**< Can use the previous table but it must be checked. Note : The previous table must have been constructed by HUF_compress{1, 4}X_repeat */
197    HUF_repeat_valid  /**< Can use the previous table and it is assumed to be valid */
198  } HUF_repeat;
199 /** HUF_compress4X_repeat() :
200  *  Same as HUF_compress4X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
201  *  If it uses hufTable it does not modify hufTable or repeat.
202  *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
203  *  If preferRepeat then the old table will always be used if valid. */
204 size_t HUF_compress4X_repeat(void* dst, size_t dstSize,
205                        const void* src, size_t srcSize,
206                        unsigned maxSymbolValue, unsigned tableLog,
207                        void* workSpace, size_t wkspSize,    /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
208                        HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2);
209 
210 /** HUF_buildCTable_wksp() :
211  *  Same as HUF_buildCTable(), but using externally allocated scratch buffer.
212  * `workSpace` must be aligned on 4-bytes boundaries, and its size must be >= HUF_CTABLE_WORKSPACE_SIZE.
213  */
214 #define HUF_CTABLE_WORKSPACE_SIZE_U32 (2*HUF_SYMBOLVALUE_MAX +1 +1)
215 #define HUF_CTABLE_WORKSPACE_SIZE (HUF_CTABLE_WORKSPACE_SIZE_U32 * sizeof(unsigned))
216 size_t HUF_buildCTable_wksp (HUF_CElt* tree,
217                        const unsigned* count, U32 maxSymbolValue, U32 maxNbBits,
218                              void* workSpace, size_t wkspSize);
219 
220 /*! HUF_readStats() :
221  *  Read compact Huffman tree, saved by HUF_writeCTable().
222  * `huffWeight` is destination buffer.
223  * @return : size read from `src` , or an error Code .
224  *  Note : Needed by HUF_readCTable() and HUF_readDTableXn() . */
225 size_t HUF_readStats(BYTE* huffWeight, size_t hwSize,
226                      U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr,
227                      const void* src, size_t srcSize);
228 
229 /** HUF_readCTable() :
230  *  Loading a CTable saved with HUF_writeCTable() */
231 size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned *hasZeroWeights);
232 
233 /** HUF_getNbBits() :
234  *  Read nbBits from CTable symbolTable, for symbol `symbolValue` presumed <= HUF_SYMBOLVALUE_MAX
235  *  Note 1 : is not inlined, as HUF_CElt definition is private
236  *  Note 2 : const void* used, so that it can provide a statically allocated table as argument (which uses type U32) */
237 U32 HUF_getNbBits(const void* symbolTable, U32 symbolValue);
238 
239 /*
240  * HUF_decompress() does the following:
241  * 1. select the decompression algorithm (X1, X2) based on pre-computed heuristics
242  * 2. build Huffman table from save, using HUF_readDTableX?()
243  * 3. decode 1 or 4 segments in parallel using HUF_decompress?X?_usingDTable()
244  */
245 
246 /** HUF_selectDecoder() :
247  *  Tells which decoder is likely to decode faster,
248  *  based on a set of pre-computed metrics.
249  * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
250  *  Assumption : 0 < dstSize <= 128 KB */
251 U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize);
252 
253 /**
254  *  The minimum workspace size for the `workSpace` used in
255  *  HUF_readDTableX1_wksp() and HUF_readDTableX2_wksp().
256  *
257  *  The space used depends on HUF_TABLELOG_MAX, ranging from ~1500 bytes when
258  *  HUF_TABLE_LOG_MAX=12 to ~1850 bytes when HUF_TABLE_LOG_MAX=15.
259  *  Buffer overflow errors may potentially occur if code modifications result in
260  *  a required workspace size greater than that specified in the following
261  *  macro.
262  */
263 #define HUF_DECOMPRESS_WORKSPACE_SIZE (2 << 10)
264 #define HUF_DECOMPRESS_WORKSPACE_SIZE_U32 (HUF_DECOMPRESS_WORKSPACE_SIZE / sizeof(U32))
265 
266 #ifndef HUF_FORCE_DECOMPRESS_X2
267 size_t HUF_readDTableX1 (HUF_DTable* DTable, const void* src, size_t srcSize);
268 size_t HUF_readDTableX1_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
269 #endif
270 #ifndef HUF_FORCE_DECOMPRESS_X1
271 size_t HUF_readDTableX2 (HUF_DTable* DTable, const void* src, size_t srcSize);
272 size_t HUF_readDTableX2_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
273 #endif
274 
275 size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
276 #ifndef HUF_FORCE_DECOMPRESS_X2
277 size_t HUF_decompress4X1_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
278 #endif
279 #ifndef HUF_FORCE_DECOMPRESS_X1
280 size_t HUF_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
281 #endif
282 
283 
284 /* ====================== */
285 /* single stream variants */
286 /* ====================== */
287 
288 size_t HUF_compress1X (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
289 size_t HUF_compress1X_wksp (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize);  /**< `workSpace` must be a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */
290 size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
291 /** HUF_compress1X_repeat() :
292  *  Same as HUF_compress1X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
293  *  If it uses hufTable it does not modify hufTable or repeat.
294  *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
295  *  If preferRepeat then the old table will always be used if valid. */
296 size_t HUF_compress1X_repeat(void* dst, size_t dstSize,
297                        const void* src, size_t srcSize,
298                        unsigned maxSymbolValue, unsigned tableLog,
299                        void* workSpace, size_t wkspSize,   /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
300                        HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2);
301 
302 size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
303 #ifndef HUF_FORCE_DECOMPRESS_X1
304 size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbol decoder */
305 #endif
306 
307 size_t HUF_decompress1X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
308 size_t HUF_decompress1X_DCtx_wksp (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);
309 #ifndef HUF_FORCE_DECOMPRESS_X2
310 size_t HUF_decompress1X1_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
311 size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< single-symbol decoder */
312 #endif
313 #ifndef HUF_FORCE_DECOMPRESS_X1
314 size_t HUF_decompress1X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
315 size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< double-symbols decoder */
316 #endif
317 
318 size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);   /**< automatic selection of sing or double symbol decoder, based on DTable */
319 #ifndef HUF_FORCE_DECOMPRESS_X2
320 size_t HUF_decompress1X1_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
321 #endif
322 #ifndef HUF_FORCE_DECOMPRESS_X1
323 size_t HUF_decompress1X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
324 #endif
325 
326 /* BMI2 variants.
327  * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0.
328  */
329 size_t HUF_decompress1X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2);
330 #ifndef HUF_FORCE_DECOMPRESS_X2
331 size_t HUF_decompress1X1_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2);
332 #endif
333 size_t HUF_decompress4X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2);
334 size_t HUF_decompress4X_hufOnly_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2);
335 
336 #endif /* HUF_STATIC_LINKING_ONLY */
337 
338 #if defined (__cplusplus)
339 }
340 #endif
341