xref: /freebsd/sys/contrib/openzfs/module/zstd/lib/common/huf.h (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only
2 /* ******************************************************************
3  * huff0 huffman codec,
4  * part of Finite State Entropy library
5  * Copyright (c) 2013-2020, Yann Collet, Facebook, Inc.
6  *
7  * You can contact the author at :
8  * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
9  *
10  * This source code is licensed under both the BSD-style license (found in the
11  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
12  * in the COPYING file in the root directory of this source tree).
13  * You may select, at your option, one of the above-listed licenses.
14 ****************************************************************** */
15 
16 #if defined (__cplusplus)
17 extern "C" {
18 #endif
19 
20 #ifndef HUF_H_298734234
21 #define HUF_H_298734234
22 
23 /* *** Dependencies *** */
24 #include <stddef.h>    /* size_t */
25 
26 
27 /* *** library symbols visibility *** */
28 /* Note : when linking with -fvisibility=hidden on gcc, or by default on Visual,
29  *        HUF symbols remain "private" (internal symbols for library only).
30  *        Set macro FSE_DLL_EXPORT to 1 if you want HUF symbols visible on DLL interface */
31 #if defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1) && defined(__GNUC__) && (__GNUC__ >= 4)
32 #  define HUF_PUBLIC_API __attribute__ ((visibility ("default")))
33 #elif defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1)   /* Visual expected */
34 #  define HUF_PUBLIC_API __declspec(dllexport)
35 #elif defined(FSE_DLL_IMPORT) && (FSE_DLL_IMPORT==1)
36 #  define HUF_PUBLIC_API __declspec(dllimport)  /* not required, just to generate faster code (saves a function pointer load from IAT and an indirect jump) */
37 #else
38 #  define HUF_PUBLIC_API
39 #endif
40 
41 
42 /* ========================== */
43 /* ***  simple functions  *** */
44 /* ========================== */
45 
46 /** HUF_compress() :
47  *  Compress content from buffer 'src', of size 'srcSize', into buffer 'dst'.
48  * 'dst' buffer must be already allocated.
49  *  Compression runs faster if `dstCapacity` >= HUF_compressBound(srcSize).
50  * `srcSize` must be <= `HUF_BLOCKSIZE_MAX` == 128 KB.
51  * @return : size of compressed data (<= `dstCapacity`).
52  *  Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
53  *                   if HUF_isError(return), compression failed (more details using HUF_getErrorName())
54  */
55 HUF_PUBLIC_API size_t HUF_compress(void* dst, size_t dstCapacity,
56                              const void* src, size_t srcSize);
57 
58 /** HUF_decompress() :
59  *  Decompress HUF data from buffer 'cSrc', of size 'cSrcSize',
60  *  into already allocated buffer 'dst', of minimum size 'dstSize'.
61  * `originalSize` : **must** be the ***exact*** size of original (uncompressed) data.
62  *  Note : in contrast with FSE, HUF_decompress can regenerate
63  *         RLE (cSrcSize==1) and uncompressed (cSrcSize==dstSize) data,
64  *         because it knows size to regenerate (originalSize).
65  * @return : size of regenerated data (== originalSize),
66  *           or an error code, which can be tested using HUF_isError()
67  */
68 HUF_PUBLIC_API size_t HUF_decompress(void* dst,  size_t originalSize,
69                                const void* cSrc, size_t cSrcSize);
70 
71 
72 /* ***   Tool functions *** */
73 #define HUF_BLOCKSIZE_MAX (128 * 1024)                  /**< maximum input size for a single block compressed with HUF_compress */
74 HUF_PUBLIC_API size_t HUF_compressBound(size_t size);   /**< maximum compressed size (worst case) */
75 
76 /* Error Management */
77 HUF_PUBLIC_API unsigned    HUF_isError(size_t code);       /**< tells if a return value is an error code */
78 HUF_PUBLIC_API const char* HUF_getErrorName(size_t code);  /**< provides error code string (useful for debugging) */
79 
80 
81 /* ***   Advanced function   *** */
82 
83 /** HUF_compress2() :
84  *  Same as HUF_compress(), but offers control over `maxSymbolValue` and `tableLog`.
85  * `maxSymbolValue` must be <= HUF_SYMBOLVALUE_MAX .
86  * `tableLog` must be `<= HUF_TABLELOG_MAX` . */
87 HUF_PUBLIC_API size_t HUF_compress2 (void* dst, size_t dstCapacity,
88                                const void* src, size_t srcSize,
89                                unsigned maxSymbolValue, unsigned tableLog);
90 
91 /** HUF_compress4X_wksp() :
92  *  Same as HUF_compress2(), but uses externally allocated `workSpace`.
93  * `workspace` must have minimum alignment of 4, and be at least as large as HUF_WORKSPACE_SIZE */
94 #define HUF_WORKSPACE_SIZE ((6 << 10) + 256)
95 #define HUF_WORKSPACE_SIZE_U32 (HUF_WORKSPACE_SIZE / sizeof(U32))
96 HUF_PUBLIC_API size_t HUF_compress4X_wksp (void* dst, size_t dstCapacity,
97                                      const void* src, size_t srcSize,
98                                      unsigned maxSymbolValue, unsigned tableLog,
99                                      void* workSpace, size_t wkspSize);
100 
101 #endif   /* HUF_H_298734234 */
102 
103 /* ******************************************************************
104  *  WARNING !!
105  *  The following section contains advanced and experimental definitions
106  *  which shall never be used in the context of a dynamic library,
107  *  because they are not guaranteed to remain stable in the future.
108  *  Only consider them in association with static linking.
109  * *****************************************************************/
110 #if defined(HUF_STATIC_LINKING_ONLY) && !defined(HUF_H_HUF_STATIC_LINKING_ONLY)
111 #define HUF_H_HUF_STATIC_LINKING_ONLY
112 
113 /* *** Dependencies *** */
114 #include "mem.h"   /* U32 */
115 
116 
117 /* *** Constants *** */
118 #define HUF_TABLELOG_MAX      12      /* max runtime value of tableLog (due to static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
119 #define HUF_TABLELOG_DEFAULT  11      /* default tableLog value when none specified */
120 #define HUF_SYMBOLVALUE_MAX  255
121 
122 #define HUF_TABLELOG_ABSOLUTEMAX  15  /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
123 #if (HUF_TABLELOG_MAX > HUF_TABLELOG_ABSOLUTEMAX)
124 #  error "HUF_TABLELOG_MAX is too large !"
125 #endif
126 
127 
128 /* ****************************************
129 *  Static allocation
130 ******************************************/
131 /* HUF buffer bounds */
132 #define HUF_CTABLEBOUND 129
133 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true when incompressible is pre-filtered with fast heuristic */
134 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
135 
136 /* static allocation of HUF's Compression Table */
137 #define HUF_CTABLE_SIZE_U32(maxSymbolValue)   ((maxSymbolValue)+1)   /* Use tables of U32, for proper alignment */
138 #define HUF_CTABLE_SIZE(maxSymbolValue)       (HUF_CTABLE_SIZE_U32(maxSymbolValue) * sizeof(U32))
139 #define HUF_CREATE_STATIC_CTABLE(name, maxSymbolValue) \
140     U32 name##hb[HUF_CTABLE_SIZE_U32(maxSymbolValue)]; \
141     void* name##hv = &(name##hb); \
142     HUF_CElt* name = (HUF_CElt*)(name##hv)   /* no final ; */
143 
144 /* static allocation of HUF's DTable */
145 typedef U32 HUF_DTable;
146 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<(maxTableLog)))
147 #define HUF_CREATE_STATIC_DTABLEX1(DTable, maxTableLog) \
148         HUF_DTable DTable[HUF_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1) * 0x01000001) }
149 #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
150         HUF_DTable DTable[HUF_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog) * 0x01000001) }
151 
152 
153 /* ****************************************
154 *  Advanced decompression functions
155 ******************************************/
156 size_t HUF_decompress4X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
157 #ifndef HUF_FORCE_DECOMPRESS_X1
158 size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
159 #endif
160 
161 size_t HUF_decompress4X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< decodes RLE and uncompressed */
162 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 */
163 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 */
164 size_t HUF_decompress4X1_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
165 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 */
166 #ifndef HUF_FORCE_DECOMPRESS_X1
167 size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
168 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 */
169 #endif
170 
171 
172 /* ****************************************
173  *  HUF detailed API
174  * ****************************************/
175 
176 /*! HUF_compress() does the following:
177  *  1. count symbol occurrence from source[] into table count[] using FSE_count() (exposed within "fse.h")
178  *  2. (optional) refine tableLog using HUF_optimalTableLog()
179  *  3. build Huffman table from count using HUF_buildCTable()
180  *  4. save Huffman table to memory buffer using HUF_writeCTable()
181  *  5. encode the data stream using HUF_compress4X_usingCTable()
182  *
183  *  The following API allows targeting specific sub-functions for advanced tasks.
184  *  For example, it's possible to compress several blocks using the same 'CTable',
185  *  or to save and regenerate 'CTable' using external methods.
186  */
187 unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);
188 typedef struct HUF_CElt_s HUF_CElt;   /* incomplete type */
189 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 */
190 size_t HUF_writeCTable (void* dst, size_t maxDstSize, const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog);
191 size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
192 size_t HUF_estimateCompressedSize(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue);
193 int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue);
194 
195 typedef enum {
196    HUF_repeat_none,  /**< Cannot use the previous table */
197    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 */
198    HUF_repeat_valid  /**< Can use the previous table and it is assumed to be valid */
199  } HUF_repeat;
200 /** HUF_compress4X_repeat() :
201  *  Same as HUF_compress4X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
202  *  If it uses hufTable it does not modify hufTable or repeat.
203  *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
204  *  If preferRepeat then the old table will always be used if valid. */
205 size_t HUF_compress4X_repeat(void* dst, size_t dstSize,
206                        const void* src, size_t srcSize,
207                        unsigned maxSymbolValue, unsigned tableLog,
208                        void* workSpace, size_t wkspSize,    /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
209                        HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2);
210 
211 /** HUF_buildCTable_wksp() :
212  *  Same as HUF_buildCTable(), but using externally allocated scratch buffer.
213  * `workSpace` must be aligned on 4-bytes boundaries, and its size must be >= HUF_CTABLE_WORKSPACE_SIZE.
214  */
215 #define HUF_CTABLE_WORKSPACE_SIZE_U32 (2*HUF_SYMBOLVALUE_MAX +1 +1)
216 #define HUF_CTABLE_WORKSPACE_SIZE (HUF_CTABLE_WORKSPACE_SIZE_U32 * sizeof(unsigned))
217 size_t HUF_buildCTable_wksp (HUF_CElt* tree,
218                        const unsigned* count, U32 maxSymbolValue, U32 maxNbBits,
219                              void* workSpace, size_t wkspSize);
220 
221 /*! HUF_readStats() :
222  *  Read compact Huffman tree, saved by HUF_writeCTable().
223  * `huffWeight` is destination buffer.
224  * @return : size read from `src` , or an error Code .
225  *  Note : Needed by HUF_readCTable() and HUF_readDTableXn() . */
226 size_t HUF_readStats(BYTE* huffWeight, size_t hwSize,
227                      U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr,
228                      const void* src, size_t srcSize);
229 
230 /** HUF_readCTable() :
231  *  Loading a CTable saved with HUF_writeCTable() */
232 size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned *hasZeroWeights);
233 
234 /** HUF_getNbBits() :
235  *  Read nbBits from CTable symbolTable, for symbol `symbolValue` presumed <= HUF_SYMBOLVALUE_MAX
236  *  Note 1 : is not inlined, as HUF_CElt definition is private
237  *  Note 2 : const void* used, so that it can provide a statically allocated table as argument (which uses type U32) */
238 U32 HUF_getNbBits(const void* symbolTable, U32 symbolValue);
239 
240 /*
241  * HUF_decompress() does the following:
242  * 1. select the decompression algorithm (X1, X2) based on pre-computed heuristics
243  * 2. build Huffman table from save, using HUF_readDTableX?()
244  * 3. decode 1 or 4 segments in parallel using HUF_decompress?X?_usingDTable()
245  */
246 
247 /** HUF_selectDecoder() :
248  *  Tells which decoder is likely to decode faster,
249  *  based on a set of pre-computed metrics.
250  * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
251  *  Assumption : 0 < dstSize <= 128 KB */
252 U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize);
253 
254 /**
255  *  The minimum workspace size for the `workSpace` used in
256  *  HUF_readDTableX1_wksp() and HUF_readDTableX2_wksp().
257  *
258  *  The space used depends on HUF_TABLELOG_MAX, ranging from ~1500 bytes when
259  *  HUF_TABLE_LOG_MAX=12 to ~1850 bytes when HUF_TABLE_LOG_MAX=15.
260  *  Buffer overflow errors may potentially occur if code modifications result in
261  *  a required workspace size greater than that specified in the following
262  *  macro.
263  */
264 #define HUF_DECOMPRESS_WORKSPACE_SIZE (2 << 10)
265 #define HUF_DECOMPRESS_WORKSPACE_SIZE_U32 (HUF_DECOMPRESS_WORKSPACE_SIZE / sizeof(U32))
266 
267 #ifndef HUF_FORCE_DECOMPRESS_X2
268 size_t HUF_readDTableX1 (HUF_DTable* DTable, const void* src, size_t srcSize);
269 size_t HUF_readDTableX1_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
270 #endif
271 #ifndef HUF_FORCE_DECOMPRESS_X1
272 size_t HUF_readDTableX2 (HUF_DTable* DTable, const void* src, size_t srcSize);
273 size_t HUF_readDTableX2_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
274 #endif
275 
276 size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
277 #ifndef HUF_FORCE_DECOMPRESS_X2
278 size_t HUF_decompress4X1_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
279 #endif
280 #ifndef HUF_FORCE_DECOMPRESS_X1
281 size_t HUF_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
282 #endif
283 
284 
285 /* ====================== */
286 /* single stream variants */
287 /* ====================== */
288 
289 size_t HUF_compress1X (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
290 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 */
291 size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
292 /** HUF_compress1X_repeat() :
293  *  Same as HUF_compress1X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
294  *  If it uses hufTable it does not modify hufTable or repeat.
295  *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
296  *  If preferRepeat then the old table will always be used if valid. */
297 size_t HUF_compress1X_repeat(void* dst, size_t dstSize,
298                        const void* src, size_t srcSize,
299                        unsigned maxSymbolValue, unsigned tableLog,
300                        void* workSpace, size_t wkspSize,   /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
301                        HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2);
302 
303 size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
304 #ifndef HUF_FORCE_DECOMPRESS_X1
305 size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbol decoder */
306 #endif
307 
308 size_t HUF_decompress1X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
309 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);
310 #ifndef HUF_FORCE_DECOMPRESS_X2
311 size_t HUF_decompress1X1_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
312 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 */
313 #endif
314 #ifndef HUF_FORCE_DECOMPRESS_X1
315 size_t HUF_decompress1X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
316 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 */
317 #endif
318 
319 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 */
320 #ifndef HUF_FORCE_DECOMPRESS_X2
321 size_t HUF_decompress1X1_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
322 #endif
323 #ifndef HUF_FORCE_DECOMPRESS_X1
324 size_t HUF_decompress1X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
325 #endif
326 
327 /* BMI2 variants.
328  * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0.
329  */
330 size_t HUF_decompress1X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2);
331 #ifndef HUF_FORCE_DECOMPRESS_X2
332 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);
333 #endif
334 size_t HUF_decompress4X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2);
335 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);
336 
337 #endif /* HUF_STATIC_LINKING_ONLY */
338 
339 #if defined (__cplusplus)
340 }
341 #endif
342