1 /*
2 * FSE : Finite State Entropy decoder
3 * Copyright (C) 2013-2015, Yann Collet.
4 *
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 * This program is free software; you can redistribute it and/or modify it under
31 * the terms of the GNU General Public License version 2 as published by the
32 * Free Software Foundation. This program is dual-licensed; you may select
33 * either version 2 of the GNU General Public License ("GPL") or BSD license
34 * ("BSD").
35 *
36 * You can contact the author at :
37 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
38 */
39
40 /* **************************************************************
41 * Compiler specifics
42 ****************************************************************/
43 #define FORCE_INLINE static __always_inline
44
45 /* **************************************************************
46 * Includes
47 ****************************************************************/
48 #include "bitstream.h"
49 #include "fse.h"
50 #include <linux/compiler.h>
51 #include <linux/kernel.h>
52 #include <linux/string.h> /* memcpy, memset */
53
54 /* **************************************************************
55 * Error Management
56 ****************************************************************/
57 #define FSE_isError ERR_isError
58 #define FSE_STATIC_ASSERT(c) \
59 { \
60 enum { FSE_static_assert = 1 / (int)(!!(c)) }; \
61 } /* use only *after* variable declarations */
62
63 /* check and forward error code */
64 #define CHECK_F(f) \
65 { \
66 size_t const e = f; \
67 if (FSE_isError(e)) \
68 return e; \
69 }
70
71 /* **************************************************************
72 * Templates
73 ****************************************************************/
74 /*
75 designed to be included
76 for type-specific functions (template emulation in C)
77 Objective is to write these functions only once, for improved maintenance
78 */
79
80 /* safety checks */
81 #ifndef FSE_FUNCTION_EXTENSION
82 #error "FSE_FUNCTION_EXTENSION must be defined"
83 #endif
84 #ifndef FSE_FUNCTION_TYPE
85 #error "FSE_FUNCTION_TYPE must be defined"
86 #endif
87
88 /* Function names */
89 #define FSE_CAT(X, Y) X##Y
90 #define FSE_FUNCTION_NAME(X, Y) FSE_CAT(X, Y)
91 #define FSE_TYPE_NAME(X, Y) FSE_CAT(X, Y)
92
93 /* Function templates */
94
FSE_buildDTable_wksp(FSE_DTable * dt,const short * normalizedCounter,unsigned maxSymbolValue,unsigned tableLog,void * workspace,size_t workspaceSize)95 size_t FSE_buildDTable_wksp(FSE_DTable *dt, const short *normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void *workspace, size_t workspaceSize)
96 {
97 void *const tdPtr = dt + 1; /* because *dt is unsigned, 32-bits aligned on 32-bits */
98 FSE_DECODE_TYPE *const tableDecode = (FSE_DECODE_TYPE *)(tdPtr);
99 U16 *symbolNext = (U16 *)workspace;
100
101 U32 const maxSV1 = maxSymbolValue + 1;
102 U32 const tableSize = 1 << tableLog;
103 U32 highThreshold = tableSize - 1;
104
105 /* Sanity Checks */
106 if (workspaceSize < sizeof(U16) * (FSE_MAX_SYMBOL_VALUE + 1))
107 return ERROR(tableLog_tooLarge);
108 if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE)
109 return ERROR(maxSymbolValue_tooLarge);
110 if (tableLog > FSE_MAX_TABLELOG)
111 return ERROR(tableLog_tooLarge);
112
113 /* Init, lay down lowprob symbols */
114 {
115 FSE_DTableHeader DTableH;
116 DTableH.tableLog = (U16)tableLog;
117 DTableH.fastMode = 1;
118 {
119 S16 const largeLimit = (S16)(1 << (tableLog - 1));
120 U32 s;
121 for (s = 0; s < maxSV1; s++) {
122 if (normalizedCounter[s] == -1) {
123 tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
124 symbolNext[s] = 1;
125 } else {
126 if (normalizedCounter[s] >= largeLimit)
127 DTableH.fastMode = 0;
128 symbolNext[s] = normalizedCounter[s];
129 }
130 }
131 }
132 memcpy(dt, &DTableH, sizeof(DTableH));
133 }
134
135 /* Spread symbols */
136 {
137 U32 const tableMask = tableSize - 1;
138 U32 const step = FSE_TABLESTEP(tableSize);
139 U32 s, position = 0;
140 for (s = 0; s < maxSV1; s++) {
141 int i;
142 for (i = 0; i < normalizedCounter[s]; i++) {
143 tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
144 position = (position + step) & tableMask;
145 while (position > highThreshold)
146 position = (position + step) & tableMask; /* lowprob area */
147 }
148 }
149 if (position != 0)
150 return ERROR(GENERIC); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
151 }
152
153 /* Build Decoding table */
154 {
155 U32 u;
156 for (u = 0; u < tableSize; u++) {
157 FSE_FUNCTION_TYPE const symbol = (FSE_FUNCTION_TYPE)(tableDecode[u].symbol);
158 U16 nextState = symbolNext[symbol]++;
159 tableDecode[u].nbBits = (BYTE)(tableLog - BIT_highbit32((U32)nextState));
160 tableDecode[u].newState = (U16)((nextState << tableDecode[u].nbBits) - tableSize);
161 }
162 }
163
164 return 0;
165 }
166
167 /*-*******************************************************
168 * Decompression (Byte symbols)
169 *********************************************************/
FSE_buildDTable_rle(FSE_DTable * dt,BYTE symbolValue)170 size_t FSE_buildDTable_rle(FSE_DTable *dt, BYTE symbolValue)
171 {
172 void *ptr = dt;
173 FSE_DTableHeader *const DTableH = (FSE_DTableHeader *)ptr;
174 void *dPtr = dt + 1;
175 FSE_decode_t *const cell = (FSE_decode_t *)dPtr;
176
177 DTableH->tableLog = 0;
178 DTableH->fastMode = 0;
179
180 cell->newState = 0;
181 cell->symbol = symbolValue;
182 cell->nbBits = 0;
183
184 return 0;
185 }
186
FSE_buildDTable_raw(FSE_DTable * dt,unsigned nbBits)187 size_t FSE_buildDTable_raw(FSE_DTable *dt, unsigned nbBits)
188 {
189 void *ptr = dt;
190 FSE_DTableHeader *const DTableH = (FSE_DTableHeader *)ptr;
191 void *dPtr = dt + 1;
192 FSE_decode_t *const dinfo = (FSE_decode_t *)dPtr;
193 const unsigned tableSize = 1 << nbBits;
194 const unsigned tableMask = tableSize - 1;
195 const unsigned maxSV1 = tableMask + 1;
196 unsigned s;
197
198 /* Sanity checks */
199 if (nbBits < 1)
200 return ERROR(GENERIC); /* min size */
201
202 /* Build Decoding Table */
203 DTableH->tableLog = (U16)nbBits;
204 DTableH->fastMode = 1;
205 for (s = 0; s < maxSV1; s++) {
206 dinfo[s].newState = 0;
207 dinfo[s].symbol = (BYTE)s;
208 dinfo[s].nbBits = (BYTE)nbBits;
209 }
210
211 return 0;
212 }
213
FSE_decompress_usingDTable_generic(void * dst,size_t maxDstSize,const void * cSrc,size_t cSrcSize,const FSE_DTable * dt,const unsigned fast)214 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(void *dst, size_t maxDstSize, const void *cSrc, size_t cSrcSize, const FSE_DTable *dt,
215 const unsigned fast)
216 {
217 BYTE *const ostart = (BYTE *)dst;
218 BYTE *op = ostart;
219 BYTE *const omax = op + maxDstSize;
220 BYTE *const olimit = omax - 3;
221
222 BIT_DStream_t bitD;
223 FSE_DState_t state1;
224 FSE_DState_t state2;
225
226 /* Init */
227 CHECK_F(BIT_initDStream(&bitD, cSrc, cSrcSize));
228
229 FSE_initDState(&state1, &bitD, dt);
230 FSE_initDState(&state2, &bitD, dt);
231
232 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
233
234 /* 4 symbols per loop */
235 for (; (BIT_reloadDStream(&bitD) == BIT_DStream_unfinished) & (op < olimit); op += 4) {
236 op[0] = FSE_GETSYMBOL(&state1);
237
238 if (FSE_MAX_TABLELOG * 2 + 7 > sizeof(bitD.bitContainer) * 8) /* This test must be static */
239 BIT_reloadDStream(&bitD);
240
241 op[1] = FSE_GETSYMBOL(&state2);
242
243 if (FSE_MAX_TABLELOG * 4 + 7 > sizeof(bitD.bitContainer) * 8) /* This test must be static */
244 {
245 if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) {
246 op += 2;
247 break;
248 }
249 }
250
251 op[2] = FSE_GETSYMBOL(&state1);
252
253 if (FSE_MAX_TABLELOG * 2 + 7 > sizeof(bitD.bitContainer) * 8) /* This test must be static */
254 BIT_reloadDStream(&bitD);
255
256 op[3] = FSE_GETSYMBOL(&state2);
257 }
258
259 /* tail */
260 /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
261 while (1) {
262 if (op > (omax - 2))
263 return ERROR(dstSize_tooSmall);
264 *op++ = FSE_GETSYMBOL(&state1);
265 if (BIT_reloadDStream(&bitD) == BIT_DStream_overflow) {
266 *op++ = FSE_GETSYMBOL(&state2);
267 break;
268 }
269
270 if (op > (omax - 2))
271 return ERROR(dstSize_tooSmall);
272 *op++ = FSE_GETSYMBOL(&state2);
273 if (BIT_reloadDStream(&bitD) == BIT_DStream_overflow) {
274 *op++ = FSE_GETSYMBOL(&state1);
275 break;
276 }
277 }
278
279 return op - ostart;
280 }
281
FSE_decompress_usingDTable(void * dst,size_t originalSize,const void * cSrc,size_t cSrcSize,const FSE_DTable * dt)282 size_t FSE_decompress_usingDTable(void *dst, size_t originalSize, const void *cSrc, size_t cSrcSize, const FSE_DTable *dt)
283 {
284 const void *ptr = dt;
285 const FSE_DTableHeader *DTableH = (const FSE_DTableHeader *)ptr;
286 const U32 fastMode = DTableH->fastMode;
287
288 /* select fast mode (static) */
289 if (fastMode)
290 return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
291 return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
292 }
293
FSE_decompress_wksp(void * dst,size_t dstCapacity,const void * cSrc,size_t cSrcSize,unsigned maxLog,void * workspace,size_t workspaceSize)294 size_t FSE_decompress_wksp(void *dst, size_t dstCapacity, const void *cSrc, size_t cSrcSize, unsigned maxLog, void *workspace, size_t workspaceSize)
295 {
296 const BYTE *const istart = (const BYTE *)cSrc;
297 const BYTE *ip = istart;
298 unsigned tableLog;
299 unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
300 size_t NCountLength;
301
302 FSE_DTable *dt;
303 short *counting;
304 size_t spaceUsed32 = 0;
305
306 FSE_STATIC_ASSERT(sizeof(FSE_DTable) == sizeof(U32));
307
308 dt = (FSE_DTable *)((U32 *)workspace + spaceUsed32);
309 spaceUsed32 += FSE_DTABLE_SIZE_U32(maxLog);
310 counting = (short *)((U32 *)workspace + spaceUsed32);
311 spaceUsed32 += ALIGN(sizeof(short) * (FSE_MAX_SYMBOL_VALUE + 1), sizeof(U32)) >> 2;
312
313 if ((spaceUsed32 << 2) > workspaceSize)
314 return ERROR(tableLog_tooLarge);
315 workspace = (U32 *)workspace + spaceUsed32;
316 workspaceSize -= (spaceUsed32 << 2);
317
318 /* normal FSE decoding mode */
319 NCountLength = FSE_readNCount(counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
320 if (FSE_isError(NCountLength))
321 return NCountLength;
322 // if (NCountLength >= cSrcSize) return ERROR(srcSize_wrong); /* too small input size; supposed to be already checked in NCountLength, only remaining
323 // case : NCountLength==cSrcSize */
324 if (tableLog > maxLog)
325 return ERROR(tableLog_tooLarge);
326 ip += NCountLength;
327 cSrcSize -= NCountLength;
328
329 CHECK_F(FSE_buildDTable_wksp(dt, counting, maxSymbolValue, tableLog, workspace, workspaceSize));
330
331 return FSE_decompress_usingDTable(dst, dstCapacity, ip, cSrcSize, dt); /* always return, even if it is an error code */
332 }
333