xref: /freebsd/sys/contrib/zstd/lib/legacy/zstd_v03.c (revision faf25f48d601ae39f5752602f3020e2e92605625)
1 /*
2  * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
3  * All rights reserved.
4  *
5  * This source code is licensed under both the BSD-style license (found in the
6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7  * in the COPYING file in the root directory of this source tree).
8  * You may select, at your option, one of the above-listed licenses.
9  */
10 
11 
12 #include <stddef.h>    /* size_t, ptrdiff_t */
13 #include "zstd_v03.h"
14 #include "../common/error_private.h"
15 
16 
17 /******************************************
18 *  Compiler-specific
19 ******************************************/
20 #if defined(_MSC_VER)   /* Visual Studio */
21 #   include <stdlib.h>  /* _byteswap_ulong */
22 #   include <intrin.h>  /* _byteswap_* */
23 #endif
24 
25 
26 
27 /* ******************************************************************
28    mem.h
29    low-level memory access routines
30    Copyright (C) 2013-2015, Yann Collet.
31 
32    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
33 
34    Redistribution and use in source and binary forms, with or without
35    modification, are permitted provided that the following conditions are
36    met:
37 
38        * Redistributions of source code must retain the above copyright
39    notice, this list of conditions and the following disclaimer.
40        * Redistributions in binary form must reproduce the above
41    copyright notice, this list of conditions and the following disclaimer
42    in the documentation and/or other materials provided with the
43    distribution.
44 
45    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
46    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
47    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
48    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
49    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
52    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
53    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
54    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
55    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 
57     You can contact the author at :
58     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
59     - Public forum : https://groups.google.com/forum/#!forum/lz4c
60 ****************************************************************** */
61 #ifndef MEM_H_MODULE
62 #define MEM_H_MODULE
63 
64 #if defined (__cplusplus)
65 extern "C" {
66 #endif
67 
68 /******************************************
69 *  Includes
70 ******************************************/
71 #include <stddef.h>    /* size_t, ptrdiff_t */
72 #include <string.h>    /* memcpy */
73 
74 
75 /******************************************
76 *  Compiler-specific
77 ******************************************/
78 #if defined(__GNUC__)
79 #  define MEM_STATIC static __attribute__((unused))
80 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
81 #  define MEM_STATIC static inline
82 #elif defined(_MSC_VER)
83 #  define MEM_STATIC static __inline
84 #else
85 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
86 #endif
87 
88 
89 /****************************************************************
90 *  Basic Types
91 *****************************************************************/
92 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
93 # if defined(_AIX)
94 #  include <inttypes.h>
95 # else
96 #  include <stdint.h> /* intptr_t */
97 # endif
98   typedef  uint8_t BYTE;
99   typedef uint16_t U16;
100   typedef  int16_t S16;
101   typedef uint32_t U32;
102   typedef  int32_t S32;
103   typedef uint64_t U64;
104   typedef  int64_t S64;
105 #else
106   typedef unsigned char       BYTE;
107   typedef unsigned short      U16;
108   typedef   signed short      S16;
109   typedef unsigned int        U32;
110   typedef   signed int        S32;
111   typedef unsigned long long  U64;
112   typedef   signed long long  S64;
113 #endif
114 
115 
116 /****************************************************************
117 *  Memory I/O
118 *****************************************************************/
119 /* MEM_FORCE_MEMORY_ACCESS
120  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
121  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
122  * The below switch allow to select different access method for improved performance.
123  * Method 0 (default) : use `memcpy()`. Safe and portable.
124  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
125  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
126  * Method 2 : direct access. This method is portable but violate C standard.
127  *            It can generate buggy code on targets generating assembly depending on alignment.
128  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
129  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
130  * Prefer these methods in priority order (0 > 1 > 2)
131  */
132 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
133 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
134 #    define MEM_FORCE_MEMORY_ACCESS 2
135 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
136   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
137 #    define MEM_FORCE_MEMORY_ACCESS 1
138 #  endif
139 #endif
140 
141 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
142 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
143 
144 MEM_STATIC unsigned MEM_isLittleEndian(void)
145 {
146     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
147     return one.c[0];
148 }
149 
150 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
151 
152 /* violates C standard on structure alignment.
153 Only use if no other choice to achieve best performance on target platform */
154 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
155 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
156 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
157 
158 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
159 
160 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
161 
162 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
163 /* currently only defined for gcc and icc */
164 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
165 
166 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
167 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
168 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
169 
170 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
171 
172 #else
173 
174 /* default method, safe and standard.
175    can sometimes prove slower */
176 
177 MEM_STATIC U16 MEM_read16(const void* memPtr)
178 {
179     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
180 }
181 
182 MEM_STATIC U32 MEM_read32(const void* memPtr)
183 {
184     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
185 }
186 
187 MEM_STATIC U64 MEM_read64(const void* memPtr)
188 {
189     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
190 }
191 
192 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
193 {
194     memcpy(memPtr, &value, sizeof(value));
195 }
196 
197 
198 #endif /* MEM_FORCE_MEMORY_ACCESS */
199 
200 
201 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
202 {
203     if (MEM_isLittleEndian())
204         return MEM_read16(memPtr);
205     else
206     {
207         const BYTE* p = (const BYTE*)memPtr;
208         return (U16)(p[0] + (p[1]<<8));
209     }
210 }
211 
212 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
213 {
214     if (MEM_isLittleEndian())
215     {
216         MEM_write16(memPtr, val);
217     }
218     else
219     {
220         BYTE* p = (BYTE*)memPtr;
221         p[0] = (BYTE)val;
222         p[1] = (BYTE)(val>>8);
223     }
224 }
225 
226 MEM_STATIC U32 MEM_readLE24(const void* memPtr)
227 {
228     return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
229 }
230 
231 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
232 {
233     if (MEM_isLittleEndian())
234         return MEM_read32(memPtr);
235     else
236     {
237         const BYTE* p = (const BYTE*)memPtr;
238         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
239     }
240 }
241 
242 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
243 {
244     if (MEM_isLittleEndian())
245         return MEM_read64(memPtr);
246     else
247     {
248         const BYTE* p = (const BYTE*)memPtr;
249         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
250                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
251     }
252 }
253 
254 
255 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
256 {
257     if (MEM_32bits())
258         return (size_t)MEM_readLE32(memPtr);
259     else
260         return (size_t)MEM_readLE64(memPtr);
261 }
262 
263 
264 #if defined (__cplusplus)
265 }
266 #endif
267 
268 #endif /* MEM_H_MODULE */
269 
270 
271 /* ******************************************************************
272    bitstream
273    Part of NewGen Entropy library
274    header file (to include)
275    Copyright (C) 2013-2015, Yann Collet.
276 
277    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
278 
279    Redistribution and use in source and binary forms, with or without
280    modification, are permitted provided that the following conditions are
281    met:
282 
283        * Redistributions of source code must retain the above copyright
284    notice, this list of conditions and the following disclaimer.
285        * Redistributions in binary form must reproduce the above
286    copyright notice, this list of conditions and the following disclaimer
287    in the documentation and/or other materials provided with the
288    distribution.
289 
290    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
291    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
292    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
293    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
294    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
295    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
296    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
297    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
298    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
299    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
300    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
301 
302    You can contact the author at :
303    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
304    - Public forum : https://groups.google.com/forum/#!forum/lz4c
305 ****************************************************************** */
306 #ifndef BITSTREAM_H_MODULE
307 #define BITSTREAM_H_MODULE
308 
309 #if defined (__cplusplus)
310 extern "C" {
311 #endif
312 
313 
314 /*
315 *  This API consists of small unitary functions, which highly benefit from being inlined.
316 *  Since link-time-optimization is not available for all compilers,
317 *  these functions are defined into a .h to be included.
318 */
319 
320 
321 /**********************************************
322 *  bitStream decompression API (read backward)
323 **********************************************/
324 typedef struct
325 {
326     size_t   bitContainer;
327     unsigned bitsConsumed;
328     const char* ptr;
329     const char* start;
330 } BIT_DStream_t;
331 
332 typedef enum { BIT_DStream_unfinished = 0,
333                BIT_DStream_endOfBuffer = 1,
334                BIT_DStream_completed = 2,
335                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
336                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
337 
338 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
339 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
340 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
341 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
342 
343 
344 
345 /******************************************
346 *  unsafe API
347 ******************************************/
348 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
349 /* faster, but works only if nbBits >= 1 */
350 
351 
352 
353 /****************************************************************
354 *  Helper functions
355 ****************************************************************/
356 MEM_STATIC unsigned BIT_highbit32 (U32 val)
357 {
358 #   if defined(_MSC_VER)   /* Visual */
359     unsigned long r=0;
360     _BitScanReverse ( &r, val );
361     return (unsigned) r;
362 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
363     return __builtin_clz (val) ^ 31;
364 #   else   /* Software version */
365     static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
366     U32 v = val;
367     unsigned r;
368     v |= v >> 1;
369     v |= v >> 2;
370     v |= v >> 4;
371     v |= v >> 8;
372     v |= v >> 16;
373     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
374     return r;
375 #   endif
376 }
377 
378 
379 
380 /**********************************************************
381 * bitStream decoding
382 **********************************************************/
383 
384 /*!BIT_initDStream
385 *  Initialize a BIT_DStream_t.
386 *  @bitD : a pointer to an already allocated BIT_DStream_t structure
387 *  @srcBuffer must point at the beginning of a bitStream
388 *  @srcSize must be the exact size of the bitStream
389 *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
390 */
391 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
392 {
393     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
394 
395     if (srcSize >=  sizeof(size_t))   /* normal case */
396     {
397         U32 contain32;
398         bitD->start = (const char*)srcBuffer;
399         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
400         bitD->bitContainer = MEM_readLEST(bitD->ptr);
401         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
402         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
403         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
404     }
405     else
406     {
407         U32 contain32;
408         bitD->start = (const char*)srcBuffer;
409         bitD->ptr   = bitD->start;
410         bitD->bitContainer = *(const BYTE*)(bitD->start);
411         switch(srcSize)
412         {
413             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
414                     /* fallthrough */
415             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
416                     /* fallthrough */
417             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
418                     /* fallthrough */
419             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
420                     /* fallthrough */
421             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
422                     /* fallthrough */
423             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
424                     /* fallthrough */
425             default:;
426         }
427         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
428         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
429         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
430         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
431     }
432 
433     return srcSize;
434 }
435 MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
436 {
437     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
438     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
439 }
440 
441 /*! BIT_lookBitsFast :
442 *   unsafe version; only works only if nbBits >= 1 */
443 MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
444 {
445     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
446     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
447 }
448 
449 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
450 {
451     bitD->bitsConsumed += nbBits;
452 }
453 
454 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
455 {
456     size_t value = BIT_lookBits(bitD, nbBits);
457     BIT_skipBits(bitD, nbBits);
458     return value;
459 }
460 
461 /*!BIT_readBitsFast :
462 *  unsafe version; only works only if nbBits >= 1 */
463 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
464 {
465     size_t value = BIT_lookBitsFast(bitD, nbBits);
466     BIT_skipBits(bitD, nbBits);
467     return value;
468 }
469 
470 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
471 {
472     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
473         return BIT_DStream_overflow;
474 
475     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
476     {
477         bitD->ptr -= bitD->bitsConsumed >> 3;
478         bitD->bitsConsumed &= 7;
479         bitD->bitContainer = MEM_readLEST(bitD->ptr);
480         return BIT_DStream_unfinished;
481     }
482     if (bitD->ptr == bitD->start)
483     {
484         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
485         return BIT_DStream_completed;
486     }
487     {
488         U32 nbBytes = bitD->bitsConsumed >> 3;
489         BIT_DStream_status result = BIT_DStream_unfinished;
490         if (bitD->ptr - nbBytes < bitD->start)
491         {
492             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
493             result = BIT_DStream_endOfBuffer;
494         }
495         bitD->ptr -= nbBytes;
496         bitD->bitsConsumed -= nbBytes*8;
497         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
498         return result;
499     }
500 }
501 
502 /*! BIT_endOfDStream
503 *   @return Tells if DStream has reached its exact end
504 */
505 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
506 {
507     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
508 }
509 
510 #if defined (__cplusplus)
511 }
512 #endif
513 
514 #endif /* BITSTREAM_H_MODULE */
515 /* ******************************************************************
516    Error codes and messages
517    Copyright (C) 2013-2015, Yann Collet
518 
519    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
520 
521    Redistribution and use in source and binary forms, with or without
522    modification, are permitted provided that the following conditions are
523    met:
524 
525        * Redistributions of source code must retain the above copyright
526    notice, this list of conditions and the following disclaimer.
527        * Redistributions in binary form must reproduce the above
528    copyright notice, this list of conditions and the following disclaimer
529    in the documentation and/or other materials provided with the
530    distribution.
531 
532    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
533    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
534    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
535    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
536    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
537    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
538    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
539    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
540    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
541    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
542    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
543 
544    You can contact the author at :
545    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
546    - Public forum : https://groups.google.com/forum/#!forum/lz4c
547 ****************************************************************** */
548 #ifndef ERROR_H_MODULE
549 #define ERROR_H_MODULE
550 
551 #if defined (__cplusplus)
552 extern "C" {
553 #endif
554 
555 
556 /******************************************
557 *  Compiler-specific
558 ******************************************/
559 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
560 #  define ERR_STATIC static inline
561 #elif defined(_MSC_VER)
562 #  define ERR_STATIC static __inline
563 #elif defined(__GNUC__)
564 #  define ERR_STATIC static __attribute__((unused))
565 #else
566 #  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
567 #endif
568 
569 
570 /******************************************
571 *  Error Management
572 ******************************************/
573 #define PREFIX(name) ZSTD_error_##name
574 
575 #define ERROR(name) (size_t)-PREFIX(name)
576 
577 #define ERROR_LIST(ITEM) \
578         ITEM(PREFIX(No_Error)) ITEM(PREFIX(GENERIC)) \
579         ITEM(PREFIX(dstSize_tooSmall)) ITEM(PREFIX(srcSize_wrong)) \
580         ITEM(PREFIX(prefix_unknown)) ITEM(PREFIX(corruption_detected)) \
581         ITEM(PREFIX(tableLog_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooSmall)) \
582         ITEM(PREFIX(maxCode))
583 
584 #define ERROR_GENERATE_ENUM(ENUM) ENUM,
585 typedef enum { ERROR_LIST(ERROR_GENERATE_ENUM) } ERR_codes;  /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
586 
587 #define ERROR_CONVERTTOSTRING(STRING) #STRING,
588 #define ERROR_GENERATE_STRING(EXPR) ERROR_CONVERTTOSTRING(EXPR)
589 static const char* ERR_strings[] = { ERROR_LIST(ERROR_GENERATE_STRING) };
590 
591 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
592 
593 ERR_STATIC const char* ERR_getErrorName(size_t code)
594 {
595     static const char* codeError = "Unspecified error code";
596     if (ERR_isError(code)) return ERR_strings[-(int)(code)];
597     return codeError;
598 }
599 
600 
601 #if defined (__cplusplus)
602 }
603 #endif
604 
605 #endif /* ERROR_H_MODULE */
606 /*
607 Constructor and Destructor of type FSE_CTable
608     Note that its size depends on 'tableLog' and 'maxSymbolValue' */
609 typedef unsigned FSE_CTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
610 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
611 
612 
613 /* ******************************************************************
614    FSE : Finite State Entropy coder
615    header file for static linking (only)
616    Copyright (C) 2013-2015, Yann Collet
617 
618    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
619 
620    Redistribution and use in source and binary forms, with or without
621    modification, are permitted provided that the following conditions are
622    met:
623 
624        * Redistributions of source code must retain the above copyright
625    notice, this list of conditions and the following disclaimer.
626        * Redistributions in binary form must reproduce the above
627    copyright notice, this list of conditions and the following disclaimer
628    in the documentation and/or other materials provided with the
629    distribution.
630 
631    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
632    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
633    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
634    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
635    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
636    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
637    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
638    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
639    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
640    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
641    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
642 
643    You can contact the author at :
644    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
645    - Public forum : https://groups.google.com/forum/#!forum/lz4c
646 ****************************************************************** */
647 #if defined (__cplusplus)
648 extern "C" {
649 #endif
650 
651 
652 /******************************************
653 *  Static allocation
654 ******************************************/
655 /* FSE buffer bounds */
656 #define FSE_NCOUNTBOUND 512
657 #define FSE_BLOCKBOUND(size) (size + (size>>7))
658 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
659 
660 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
661 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
662 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<maxTableLog))
663 
664 
665 /******************************************
666 *  FSE advanced API
667 ******************************************/
668 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
669 /* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
670 
671 static size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
672 /* build a fake FSE_DTable, designed to always generate the same symbolValue */
673 
674 
675 /******************************************
676 *  FSE symbol decompression API
677 ******************************************/
678 typedef struct
679 {
680     size_t      state;
681     const void* table;   /* precise table may vary, depending on U16 */
682 } FSE_DState_t;
683 
684 
685 static void     FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
686 
687 static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
688 
689 static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
690 
691 
692 /******************************************
693 *  FSE unsafe API
694 ******************************************/
695 static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
696 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
697 
698 
699 /******************************************
700 *  Implementation of inline functions
701 ******************************************/
702 
703 /* decompression */
704 
705 typedef struct {
706     U16 tableLog;
707     U16 fastMode;
708 } FSE_DTableHeader;   /* sizeof U32 */
709 
710 typedef struct
711 {
712     unsigned short newState;
713     unsigned char  symbol;
714     unsigned char  nbBits;
715 } FSE_decode_t;   /* size == U32 */
716 
717 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
718 {
719     FSE_DTableHeader DTableH;
720     memcpy(&DTableH, dt, sizeof(DTableH));
721     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
722     BIT_reloadDStream(bitD);
723     DStatePtr->table = dt + 1;
724 }
725 
726 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
727 {
728     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
729     const U32  nbBits = DInfo.nbBits;
730     BYTE symbol = DInfo.symbol;
731     size_t lowBits = BIT_readBits(bitD, nbBits);
732 
733     DStatePtr->state = DInfo.newState + lowBits;
734     return symbol;
735 }
736 
737 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
738 {
739     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
740     const U32 nbBits = DInfo.nbBits;
741     BYTE symbol = DInfo.symbol;
742     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
743 
744     DStatePtr->state = DInfo.newState + lowBits;
745     return symbol;
746 }
747 
748 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
749 {
750     return DStatePtr->state == 0;
751 }
752 
753 
754 #if defined (__cplusplus)
755 }
756 #endif
757 /* ******************************************************************
758    Huff0 : Huffman coder, part of New Generation Entropy library
759    header file for static linking (only)
760    Copyright (C) 2013-2015, Yann Collet
761 
762    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
763 
764    Redistribution and use in source and binary forms, with or without
765    modification, are permitted provided that the following conditions are
766    met:
767 
768        * Redistributions of source code must retain the above copyright
769    notice, this list of conditions and the following disclaimer.
770        * Redistributions in binary form must reproduce the above
771    copyright notice, this list of conditions and the following disclaimer
772    in the documentation and/or other materials provided with the
773    distribution.
774 
775    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
776    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
777    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
778    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
779    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
780    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
781    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
782    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
783    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
784    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
785    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
786 
787    You can contact the author at :
788    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
789    - Public forum : https://groups.google.com/forum/#!forum/lz4c
790 ****************************************************************** */
791 
792 #if defined (__cplusplus)
793 extern "C" {
794 #endif
795 
796 /******************************************
797 *  Static allocation macros
798 ******************************************/
799 /* Huff0 buffer bounds */
800 #define HUF_CTABLEBOUND 129
801 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
802 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
803 
804 /* static allocation of Huff0's DTable */
805 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<maxTableLog))  /* nb Cells; use unsigned short for X2, unsigned int for X4 */
806 #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
807         unsigned short DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
808 #define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
809         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
810 #define HUF_CREATE_STATIC_DTABLEX6(DTable, maxTableLog) \
811         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog) * 3 / 2] = { maxTableLog }
812 
813 
814 /******************************************
815 *  Advanced functions
816 ******************************************/
817 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
818 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbols decoder */
819 
820 
821 #if defined (__cplusplus)
822 }
823 #endif
824 
825 /*
826     zstd - standard compression library
827     Header File
828     Copyright (C) 2014-2015, Yann Collet.
829 
830     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
831 
832     Redistribution and use in source and binary forms, with or without
833     modification, are permitted provided that the following conditions are
834     met:
835     * Redistributions of source code must retain the above copyright
836     notice, this list of conditions and the following disclaimer.
837     * Redistributions in binary form must reproduce the above
838     copyright notice, this list of conditions and the following disclaimer
839     in the documentation and/or other materials provided with the
840     distribution.
841     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
842     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
843     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
844     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
845     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
846     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
847     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
848     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
849     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
850     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
851     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
852 
853     You can contact the author at :
854     - zstd source repository : https://github.com/Cyan4973/zstd
855     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
856 */
857 
858 #if defined (__cplusplus)
859 extern "C" {
860 #endif
861 
862 /* *************************************
863 *  Includes
864 ***************************************/
865 #include <stddef.h>   /* size_t */
866 
867 
868 /* *************************************
869 *  Version
870 ***************************************/
871 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
872 #define ZSTD_VERSION_MINOR    2    /* for new (non-breaking) interface capabilities */
873 #define ZSTD_VERSION_RELEASE  2    /* for tweaks, bug-fixes, or development */
874 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
875 
876 
877 /* *************************************
878 *  Advanced functions
879 ***************************************/
880 typedef struct ZSTD_CCtx_s ZSTD_CCtx;   /* incomplete type */
881 
882 #if defined (__cplusplus)
883 }
884 #endif
885 /*
886     zstd - standard compression library
887     Header File for static linking only
888     Copyright (C) 2014-2015, Yann Collet.
889 
890     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
891 
892     Redistribution and use in source and binary forms, with or without
893     modification, are permitted provided that the following conditions are
894     met:
895     * Redistributions of source code must retain the above copyright
896     notice, this list of conditions and the following disclaimer.
897     * Redistributions in binary form must reproduce the above
898     copyright notice, this list of conditions and the following disclaimer
899     in the documentation and/or other materials provided with the
900     distribution.
901     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
902     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
903     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
904     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
905     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
906     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
907     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
908     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
909     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
910     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
911     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
912 
913     You can contact the author at :
914     - zstd source repository : https://github.com/Cyan4973/zstd
915     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
916 */
917 
918 /* The objects defined into this file should be considered experimental.
919  * They are not labelled stable, as their prototype may change in the future.
920  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
921  */
922 
923 #if defined (__cplusplus)
924 extern "C" {
925 #endif
926 
927 /* *************************************
928 *  Streaming functions
929 ***************************************/
930 
931 typedef struct ZSTD_DCtx_s ZSTD_DCtx;
932 
933 /*
934   Use above functions alternatively.
935   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
936   ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
937   Result is the number of bytes regenerated within 'dst'.
938   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
939 */
940 
941 /* *************************************
942 *  Prefix - version detection
943 ***************************************/
944 #define ZSTD_magicNumber 0xFD2FB523   /* v0.3 */
945 
946 
947 #if defined (__cplusplus)
948 }
949 #endif
950 /* ******************************************************************
951    FSE : Finite State Entropy coder
952    Copyright (C) 2013-2015, Yann Collet.
953 
954    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
955 
956    Redistribution and use in source and binary forms, with or without
957    modification, are permitted provided that the following conditions are
958    met:
959 
960        * Redistributions of source code must retain the above copyright
961    notice, this list of conditions and the following disclaimer.
962        * Redistributions in binary form must reproduce the above
963    copyright notice, this list of conditions and the following disclaimer
964    in the documentation and/or other materials provided with the
965    distribution.
966 
967    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
968    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
969    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
970    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
971    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
972    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
973    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
974    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
975    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
976    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
977    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
978 
979     You can contact the author at :
980     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
981     - Public forum : https://groups.google.com/forum/#!forum/lz4c
982 ****************************************************************** */
983 
984 #ifndef FSE_COMMONDEFS_ONLY
985 
986 /****************************************************************
987 *  Tuning parameters
988 ****************************************************************/
989 /* MEMORY_USAGE :
990 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
991 *  Increasing memory usage improves compression ratio
992 *  Reduced memory usage can improve speed, due to cache effect
993 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
994 #define FSE_MAX_MEMORY_USAGE 14
995 #define FSE_DEFAULT_MEMORY_USAGE 13
996 
997 /* FSE_MAX_SYMBOL_VALUE :
998 *  Maximum symbol value authorized.
999 *  Required for proper stack allocation */
1000 #define FSE_MAX_SYMBOL_VALUE 255
1001 
1002 
1003 /****************************************************************
1004 *  template functions type & suffix
1005 ****************************************************************/
1006 #define FSE_FUNCTION_TYPE BYTE
1007 #define FSE_FUNCTION_EXTENSION
1008 
1009 
1010 /****************************************************************
1011 *  Byte symbol type
1012 ****************************************************************/
1013 #endif   /* !FSE_COMMONDEFS_ONLY */
1014 
1015 
1016 /****************************************************************
1017 *  Compiler specifics
1018 ****************************************************************/
1019 #ifdef _MSC_VER    /* Visual Studio */
1020 #  define FORCE_INLINE static __forceinline
1021 #  include <intrin.h>                    /* For Visual 2005 */
1022 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1023 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
1024 #else
1025 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
1026 #    ifdef __GNUC__
1027 #      define FORCE_INLINE static inline __attribute__((always_inline))
1028 #    else
1029 #      define FORCE_INLINE static inline
1030 #    endif
1031 #  else
1032 #    define FORCE_INLINE static
1033 #  endif /* __STDC_VERSION__ */
1034 #endif
1035 
1036 
1037 /****************************************************************
1038 *  Includes
1039 ****************************************************************/
1040 #include <stdlib.h>     /* malloc, free, qsort */
1041 #include <string.h>     /* memcpy, memset */
1042 #include <stdio.h>      /* printf (debug) */
1043 
1044 /****************************************************************
1045 *  Constants
1046 *****************************************************************/
1047 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
1048 #define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
1049 #define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
1050 #define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
1051 #define FSE_MIN_TABLELOG 5
1052 
1053 #define FSE_TABLELOG_ABSOLUTE_MAX 15
1054 #if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
1055 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
1056 #endif
1057 
1058 
1059 /****************************************************************
1060 *  Error Management
1061 ****************************************************************/
1062 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1063 
1064 
1065 /****************************************************************
1066 *  Complex types
1067 ****************************************************************/
1068 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
1069 
1070 
1071 /****************************************************************
1072 *  Templates
1073 ****************************************************************/
1074 /*
1075   designed to be included
1076   for type-specific functions (template emulation in C)
1077   Objective is to write these functions only once, for improved maintenance
1078 */
1079 
1080 /* safety checks */
1081 #ifndef FSE_FUNCTION_EXTENSION
1082 #  error "FSE_FUNCTION_EXTENSION must be defined"
1083 #endif
1084 #ifndef FSE_FUNCTION_TYPE
1085 #  error "FSE_FUNCTION_TYPE must be defined"
1086 #endif
1087 
1088 /* Function names */
1089 #define FSE_CAT(X,Y) X##Y
1090 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
1091 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
1092 
1093 
1094 /* Function templates */
1095 
1096 #define FSE_DECODE_TYPE FSE_decode_t
1097 
1098 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
1099 
1100 static size_t FSE_buildDTable
1101 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
1102 {
1103     void* ptr = dt+1;
1104     FSE_DTableHeader DTableH;
1105     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)ptr;
1106     const U32 tableSize = 1 << tableLog;
1107     const U32 tableMask = tableSize-1;
1108     const U32 step = FSE_tableStep(tableSize);
1109     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
1110     U32 position = 0;
1111     U32 highThreshold = tableSize-1;
1112     const S16 largeLimit= (S16)(1 << (tableLog-1));
1113     U32 noLarge = 1;
1114     U32 s;
1115 
1116     /* Sanity Checks */
1117     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
1118     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
1119 
1120     /* Init, lay down lowprob symbols */
1121     DTableH.tableLog = (U16)tableLog;
1122     for (s=0; s<=maxSymbolValue; s++)
1123     {
1124         if (normalizedCounter[s]==-1)
1125         {
1126             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
1127             symbolNext[s] = 1;
1128         }
1129         else
1130         {
1131             if (normalizedCounter[s] >= largeLimit) noLarge=0;
1132             symbolNext[s] = normalizedCounter[s];
1133         }
1134     }
1135 
1136     /* Spread symbols */
1137     for (s=0; s<=maxSymbolValue; s++)
1138     {
1139         int i;
1140         for (i=0; i<normalizedCounter[s]; i++)
1141         {
1142             tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
1143             position = (position + step) & tableMask;
1144             while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
1145         }
1146     }
1147 
1148     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
1149 
1150     /* Build Decoding table */
1151     {
1152         U32 i;
1153         for (i=0; i<tableSize; i++)
1154         {
1155             FSE_FUNCTION_TYPE symbol = (FSE_FUNCTION_TYPE)(tableDecode[i].symbol);
1156             U16 nextState = symbolNext[symbol]++;
1157             tableDecode[i].nbBits = (BYTE) (tableLog - BIT_highbit32 ((U32)nextState) );
1158             tableDecode[i].newState = (U16) ( (nextState << tableDecode[i].nbBits) - tableSize);
1159         }
1160     }
1161 
1162     DTableH.fastMode = (U16)noLarge;
1163     memcpy(dt, &DTableH, sizeof(DTableH));
1164     return 0;
1165 }
1166 
1167 
1168 #ifndef FSE_COMMONDEFS_ONLY
1169 /******************************************
1170 *  FSE helper functions
1171 ******************************************/
1172 static unsigned FSE_isError(size_t code) { return ERR_isError(code); }
1173 
1174 
1175 /****************************************************************
1176 *  FSE NCount encoding-decoding
1177 ****************************************************************/
1178 static short FSE_abs(short a)
1179 {
1180     return a<0 ? -a : a;
1181 }
1182 
1183 static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
1184                  const void* headerBuffer, size_t hbSize)
1185 {
1186     const BYTE* const istart = (const BYTE*) headerBuffer;
1187     const BYTE* const iend = istart + hbSize;
1188     const BYTE* ip = istart;
1189     int nbBits;
1190     int remaining;
1191     int threshold;
1192     U32 bitStream;
1193     int bitCount;
1194     unsigned charnum = 0;
1195     int previous0 = 0;
1196 
1197     if (hbSize < 4) return ERROR(srcSize_wrong);
1198     bitStream = MEM_readLE32(ip);
1199     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
1200     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
1201     bitStream >>= 4;
1202     bitCount = 4;
1203     *tableLogPtr = nbBits;
1204     remaining = (1<<nbBits)+1;
1205     threshold = 1<<nbBits;
1206     nbBits++;
1207 
1208     while ((remaining>1) && (charnum<=*maxSVPtr))
1209     {
1210         if (previous0)
1211         {
1212             unsigned n0 = charnum;
1213             while ((bitStream & 0xFFFF) == 0xFFFF)
1214             {
1215                 n0+=24;
1216                 if (ip < iend-5)
1217                 {
1218                     ip+=2;
1219                     bitStream = MEM_readLE32(ip) >> bitCount;
1220                 }
1221                 else
1222                 {
1223                     bitStream >>= 16;
1224                     bitCount+=16;
1225                 }
1226             }
1227             while ((bitStream & 3) == 3)
1228             {
1229                 n0+=3;
1230                 bitStream>>=2;
1231                 bitCount+=2;
1232             }
1233             n0 += bitStream & 3;
1234             bitCount += 2;
1235             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
1236             while (charnum < n0) normalizedCounter[charnum++] = 0;
1237             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1238             {
1239                 ip += bitCount>>3;
1240                 bitCount &= 7;
1241                 bitStream = MEM_readLE32(ip) >> bitCount;
1242             }
1243             else
1244                 bitStream >>= 2;
1245         }
1246         {
1247             const short max = (short)((2*threshold-1)-remaining);
1248             short count;
1249 
1250             if ((bitStream & (threshold-1)) < (U32)max)
1251             {
1252                 count = (short)(bitStream & (threshold-1));
1253                 bitCount   += nbBits-1;
1254             }
1255             else
1256             {
1257                 count = (short)(bitStream & (2*threshold-1));
1258                 if (count >= threshold) count -= max;
1259                 bitCount   += nbBits;
1260             }
1261 
1262             count--;   /* extra accuracy */
1263             remaining -= FSE_abs(count);
1264             normalizedCounter[charnum++] = count;
1265             previous0 = !count;
1266             while (remaining < threshold)
1267             {
1268                 nbBits--;
1269                 threshold >>= 1;
1270             }
1271 
1272             {
1273                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1274                 {
1275                     ip += bitCount>>3;
1276                     bitCount &= 7;
1277                 }
1278                 else
1279                 {
1280                     bitCount -= (int)(8 * (iend - 4 - ip));
1281                     ip = iend - 4;
1282                 }
1283                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
1284             }
1285         }
1286     }
1287     if (remaining != 1) return ERROR(GENERIC);
1288     *maxSVPtr = charnum-1;
1289 
1290     ip += (bitCount+7)>>3;
1291     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
1292     return ip-istart;
1293 }
1294 
1295 
1296 /*********************************************************
1297 *  Decompression (Byte symbols)
1298 *********************************************************/
1299 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
1300 {
1301     void* ptr = dt;
1302     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1303     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;
1304 
1305     DTableH->tableLog = 0;
1306     DTableH->fastMode = 0;
1307 
1308     cell->newState = 0;
1309     cell->symbol = symbolValue;
1310     cell->nbBits = 0;
1311 
1312     return 0;
1313 }
1314 
1315 
1316 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
1317 {
1318     void* ptr = dt;
1319     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1320     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;
1321     const unsigned tableSize = 1 << nbBits;
1322     const unsigned tableMask = tableSize - 1;
1323     const unsigned maxSymbolValue = tableMask;
1324     unsigned s;
1325 
1326     /* Sanity checks */
1327     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
1328 
1329     /* Build Decoding Table */
1330     DTableH->tableLog = (U16)nbBits;
1331     DTableH->fastMode = 1;
1332     for (s=0; s<=maxSymbolValue; s++)
1333     {
1334         dinfo[s].newState = 0;
1335         dinfo[s].symbol = (BYTE)s;
1336         dinfo[s].nbBits = (BYTE)nbBits;
1337     }
1338 
1339     return 0;
1340 }
1341 
1342 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
1343           void* dst, size_t maxDstSize,
1344     const void* cSrc, size_t cSrcSize,
1345     const FSE_DTable* dt, const unsigned fast)
1346 {
1347     BYTE* const ostart = (BYTE*) dst;
1348     BYTE* op = ostart;
1349     BYTE* const omax = op + maxDstSize;
1350     BYTE* const olimit = omax-3;
1351 
1352     BIT_DStream_t bitD;
1353     FSE_DState_t state1;
1354     FSE_DState_t state2;
1355     size_t errorCode;
1356 
1357     /* Init */
1358     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
1359     if (FSE_isError(errorCode)) return errorCode;
1360 
1361     FSE_initDState(&state1, &bitD, dt);
1362     FSE_initDState(&state2, &bitD, dt);
1363 
1364 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
1365 
1366     /* 4 symbols per loop */
1367     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op<olimit) ; op+=4)
1368     {
1369         op[0] = FSE_GETSYMBOL(&state1);
1370 
1371         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1372             BIT_reloadDStream(&bitD);
1373 
1374         op[1] = FSE_GETSYMBOL(&state2);
1375 
1376         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1377             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
1378 
1379         op[2] = FSE_GETSYMBOL(&state1);
1380 
1381         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1382             BIT_reloadDStream(&bitD);
1383 
1384         op[3] = FSE_GETSYMBOL(&state2);
1385     }
1386 
1387     /* tail */
1388     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
1389     while (1)
1390     {
1391         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
1392             break;
1393 
1394         *op++ = FSE_GETSYMBOL(&state1);
1395 
1396         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
1397             break;
1398 
1399         *op++ = FSE_GETSYMBOL(&state2);
1400     }
1401 
1402     /* end ? */
1403     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
1404         return op-ostart;
1405 
1406     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
1407 
1408     return ERROR(corruption_detected);
1409 }
1410 
1411 
1412 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
1413                             const void* cSrc, size_t cSrcSize,
1414                             const FSE_DTable* dt)
1415 {
1416     FSE_DTableHeader DTableH;
1417     memcpy(&DTableH, dt, sizeof(DTableH));
1418 
1419     /* select fast mode (static) */
1420     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
1421     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
1422 }
1423 
1424 
1425 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
1426 {
1427     const BYTE* const istart = (const BYTE*)cSrc;
1428     const BYTE* ip = istart;
1429     short counting[FSE_MAX_SYMBOL_VALUE+1];
1430     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
1431     unsigned tableLog;
1432     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
1433     size_t errorCode;
1434 
1435     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
1436 
1437     /* normal FSE decoding mode */
1438     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
1439     if (FSE_isError(errorCode)) return errorCode;
1440     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
1441     ip += errorCode;
1442     cSrcSize -= errorCode;
1443 
1444     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
1445     if (FSE_isError(errorCode)) return errorCode;
1446 
1447     /* always return, even if it is an error code */
1448     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
1449 }
1450 
1451 
1452 
1453 #endif   /* FSE_COMMONDEFS_ONLY */
1454 /* ******************************************************************
1455    Huff0 : Huffman coder, part of New Generation Entropy library
1456    Copyright (C) 2013-2015, Yann Collet.
1457 
1458    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1459 
1460    Redistribution and use in source and binary forms, with or without
1461    modification, are permitted provided that the following conditions are
1462    met:
1463 
1464        * Redistributions of source code must retain the above copyright
1465    notice, this list of conditions and the following disclaimer.
1466        * Redistributions in binary form must reproduce the above
1467    copyright notice, this list of conditions and the following disclaimer
1468    in the documentation and/or other materials provided with the
1469    distribution.
1470 
1471    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1472    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1473    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1474    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1475    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1476    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1477    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1478    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1479    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1480    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1481    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1482 
1483     You can contact the author at :
1484     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
1485     - Public forum : https://groups.google.com/forum/#!forum/lz4c
1486 ****************************************************************** */
1487 
1488 /****************************************************************
1489 *  Compiler specifics
1490 ****************************************************************/
1491 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
1492 /* inline is defined */
1493 #elif defined(_MSC_VER)
1494 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1495 #  define inline __inline
1496 #else
1497 #  define inline /* disable inline */
1498 #endif
1499 
1500 
1501 /****************************************************************
1502 *  Includes
1503 ****************************************************************/
1504 #include <stdlib.h>     /* malloc, free, qsort */
1505 #include <string.h>     /* memcpy, memset */
1506 #include <stdio.h>      /* printf (debug) */
1507 
1508 /****************************************************************
1509 *  Error Management
1510 ****************************************************************/
1511 #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1512 
1513 
1514 /******************************************
1515 *  Helper functions
1516 ******************************************/
1517 static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
1518 
1519 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
1520 #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
1521 #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
1522 #define HUF_MAX_SYMBOL_VALUE 255
1523 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
1524 #  error "HUF_MAX_TABLELOG is too large !"
1525 #endif
1526 
1527 
1528 
1529 /*********************************************************
1530 *  Huff0 : Huffman block decompression
1531 *********************************************************/
1532 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
1533 
1534 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
1535 
1536 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
1537 
1538 /*! HUF_readStats
1539     Read compact Huffman tree, saved by HUF_writeCTable
1540     @huffWeight : destination buffer
1541     @return : size read from `src`
1542 */
1543 static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
1544                             U32* nbSymbolsPtr, U32* tableLogPtr,
1545                             const void* src, size_t srcSize)
1546 {
1547     U32 weightTotal;
1548     U32 tableLog;
1549     const BYTE* ip = (const BYTE*) src;
1550     size_t iSize;
1551     size_t oSize;
1552     U32 n;
1553 
1554     if (!srcSize) return ERROR(srcSize_wrong);
1555     iSize = ip[0];
1556     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
1557 
1558     if (iSize >= 128)  /* special header */
1559     {
1560         if (iSize >= (242))   /* RLE */
1561         {
1562             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
1563             oSize = l[iSize-242];
1564             memset(huffWeight, 1, hwSize);
1565             iSize = 0;
1566         }
1567         else   /* Incompressible */
1568         {
1569             oSize = iSize - 127;
1570             iSize = ((oSize+1)/2);
1571             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1572             if (oSize >= hwSize) return ERROR(corruption_detected);
1573             ip += 1;
1574             for (n=0; n<oSize; n+=2)
1575             {
1576                 huffWeight[n]   = ip[n/2] >> 4;
1577                 huffWeight[n+1] = ip[n/2] & 15;
1578             }
1579         }
1580     }
1581     else  /* header compressed with FSE (normal case) */
1582     {
1583         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1584         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
1585         if (FSE_isError(oSize)) return oSize;
1586     }
1587 
1588     /* collect weight stats */
1589     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
1590     weightTotal = 0;
1591     for (n=0; n<oSize; n++)
1592     {
1593         if (huffWeight[n] >= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1594         rankStats[huffWeight[n]]++;
1595         weightTotal += (1 << huffWeight[n]) >> 1;
1596     }
1597     if (weightTotal == 0) return ERROR(corruption_detected);
1598 
1599     /* get last non-null symbol weight (implied, total must be 2^n) */
1600     tableLog = BIT_highbit32(weightTotal) + 1;
1601     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1602     {
1603         U32 total = 1 << tableLog;
1604         U32 rest = total - weightTotal;
1605         U32 verif = 1 << BIT_highbit32(rest);
1606         U32 lastWeight = BIT_highbit32(rest) + 1;
1607         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
1608         huffWeight[oSize] = (BYTE)lastWeight;
1609         rankStats[lastWeight]++;
1610     }
1611 
1612     /* check tree construction validity */
1613     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
1614 
1615     /* results */
1616     *nbSymbolsPtr = (U32)(oSize+1);
1617     *tableLogPtr = tableLog;
1618     return iSize+1;
1619 }
1620 
1621 
1622 /**************************/
1623 /* single-symbol decoding */
1624 /**************************/
1625 
1626 static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
1627 {
1628     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
1629     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
1630     U32 tableLog = 0;
1631     const BYTE* ip = (const BYTE*) src;
1632     size_t iSize = ip[0];
1633     U32 nbSymbols = 0;
1634     U32 n;
1635     U32 nextRankStart;
1636     void* ptr = DTable+1;
1637     HUF_DEltX2* const dt = (HUF_DEltX2*)(ptr);
1638 
1639     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
1640     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
1641 
1642     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
1643     if (HUF_isError(iSize)) return iSize;
1644 
1645     /* check result */
1646     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
1647     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
1648 
1649     /* Prepare ranks */
1650     nextRankStart = 0;
1651     for (n=1; n<=tableLog; n++)
1652     {
1653         U32 current = nextRankStart;
1654         nextRankStart += (rankVal[n] << (n-1));
1655         rankVal[n] = current;
1656     }
1657 
1658     /* fill DTable */
1659     for (n=0; n<nbSymbols; n++)
1660     {
1661         const U32 w = huffWeight[n];
1662         const U32 length = (1 << w) >> 1;
1663         U32 i;
1664         HUF_DEltX2 D;
1665         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
1666         for (i = rankVal[w]; i < rankVal[w] + length; i++)
1667             dt[i] = D;
1668         rankVal[w] += length;
1669     }
1670 
1671     return iSize;
1672 }
1673 
1674 static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
1675 {
1676         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
1677         const BYTE c = dt[val].byte;
1678         BIT_skipBits(Dstream, dt[val].nbBits);
1679         return c;
1680 }
1681 
1682 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
1683     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
1684 
1685 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
1686     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
1687         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1688 
1689 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
1690     if (MEM_64bits()) \
1691         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1692 
1693 static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
1694 {
1695     BYTE* const pStart = p;
1696 
1697     /* up to 4 symbols at a time */
1698     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
1699     {
1700         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1701         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
1702         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1703         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1704     }
1705 
1706     /* closer to the end */
1707     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
1708         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1709 
1710     /* no more data to retrieve from bitstream, hence no need to reload */
1711     while (p < pEnd)
1712         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1713 
1714     return pEnd-pStart;
1715 }
1716 
1717 
1718 static size_t HUF_decompress4X2_usingDTable(
1719           void* dst,  size_t dstSize,
1720     const void* cSrc, size_t cSrcSize,
1721     const U16* DTable)
1722 {
1723     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
1724 
1725     {
1726         const BYTE* const istart = (const BYTE*) cSrc;
1727         BYTE* const ostart = (BYTE*) dst;
1728         BYTE* const oend = ostart + dstSize;
1729 
1730         const void* ptr = DTable;
1731         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)ptr) +1;
1732         const U32 dtLog = DTable[0];
1733         size_t errorCode;
1734 
1735         /* Init */
1736         BIT_DStream_t bitD1;
1737         BIT_DStream_t bitD2;
1738         BIT_DStream_t bitD3;
1739         BIT_DStream_t bitD4;
1740         const size_t length1 = MEM_readLE16(istart);
1741         const size_t length2 = MEM_readLE16(istart+2);
1742         const size_t length3 = MEM_readLE16(istart+4);
1743         size_t length4;
1744         const BYTE* const istart1 = istart + 6;  /* jumpTable */
1745         const BYTE* const istart2 = istart1 + length1;
1746         const BYTE* const istart3 = istart2 + length2;
1747         const BYTE* const istart4 = istart3 + length3;
1748         const size_t segmentSize = (dstSize+3) / 4;
1749         BYTE* const opStart2 = ostart + segmentSize;
1750         BYTE* const opStart3 = opStart2 + segmentSize;
1751         BYTE* const opStart4 = opStart3 + segmentSize;
1752         BYTE* op1 = ostart;
1753         BYTE* op2 = opStart2;
1754         BYTE* op3 = opStart3;
1755         BYTE* op4 = opStart4;
1756         U32 endSignal;
1757 
1758         length4 = cSrcSize - (length1 + length2 + length3 + 6);
1759         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
1760         errorCode = BIT_initDStream(&bitD1, istart1, length1);
1761         if (HUF_isError(errorCode)) return errorCode;
1762         errorCode = BIT_initDStream(&bitD2, istart2, length2);
1763         if (HUF_isError(errorCode)) return errorCode;
1764         errorCode = BIT_initDStream(&bitD3, istart3, length3);
1765         if (HUF_isError(errorCode)) return errorCode;
1766         errorCode = BIT_initDStream(&bitD4, istart4, length4);
1767         if (HUF_isError(errorCode)) return errorCode;
1768 
1769         /* 16-32 symbols per loop (4-8 symbols per stream) */
1770         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1771         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
1772         {
1773             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1774             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1775             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1776             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1777             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
1778             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
1779             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
1780             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
1781             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1782             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1783             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1784             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1785             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
1786             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
1787             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
1788             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
1789 
1790             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1791         }
1792 
1793         /* check corruption */
1794         if (op1 > opStart2) return ERROR(corruption_detected);
1795         if (op2 > opStart3) return ERROR(corruption_detected);
1796         if (op3 > opStart4) return ERROR(corruption_detected);
1797         /* note : op4 supposed already verified within main loop */
1798 
1799         /* finish bitStreams one by one */
1800         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
1801         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
1802         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
1803         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
1804 
1805         /* check */
1806         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
1807         if (!endSignal) return ERROR(corruption_detected);
1808 
1809         /* decoded size */
1810         return dstSize;
1811     }
1812 }
1813 
1814 
1815 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
1816 {
1817     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
1818     const BYTE* ip = (const BYTE*) cSrc;
1819     size_t errorCode;
1820 
1821     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
1822     if (HUF_isError(errorCode)) return errorCode;
1823     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
1824     ip += errorCode;
1825     cSrcSize -= errorCode;
1826 
1827     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
1828 }
1829 
1830 
1831 /***************************/
1832 /* double-symbols decoding */
1833 /***************************/
1834 
1835 static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
1836                            const U32* rankValOrigin, const int minWeight,
1837                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
1838                            U32 nbBitsBaseline, U16 baseSeq)
1839 {
1840     HUF_DEltX4 DElt;
1841     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1842     U32 s;
1843 
1844     /* get pre-calculated rankVal */
1845     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1846 
1847     /* fill skipped values */
1848     if (minWeight>1)
1849     {
1850         U32 i, skipSize = rankVal[minWeight];
1851         MEM_writeLE16(&(DElt.sequence), baseSeq);
1852         DElt.nbBits   = (BYTE)(consumed);
1853         DElt.length   = 1;
1854         for (i = 0; i < skipSize; i++)
1855             DTable[i] = DElt;
1856     }
1857 
1858     /* fill DTable */
1859     for (s=0; s<sortedListSize; s++)   /* note : sortedSymbols already skipped */
1860     {
1861         const U32 symbol = sortedSymbols[s].symbol;
1862         const U32 weight = sortedSymbols[s].weight;
1863         const U32 nbBits = nbBitsBaseline - weight;
1864         const U32 length = 1 << (sizeLog-nbBits);
1865         const U32 start = rankVal[weight];
1866         U32 i = start;
1867         const U32 end = start + length;
1868 
1869         MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
1870         DElt.nbBits = (BYTE)(nbBits + consumed);
1871         DElt.length = 2;
1872         do { DTable[i++] = DElt; } while (i<end);   /* since length >= 1 */
1873 
1874         rankVal[weight] += length;
1875     }
1876 }
1877 
1878 typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
1879 
1880 static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
1881                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
1882                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
1883                            const U32 nbBitsBaseline)
1884 {
1885     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1886     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
1887     const U32 minBits  = nbBitsBaseline - maxWeight;
1888     U32 s;
1889 
1890     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1891 
1892     /* fill DTable */
1893     for (s=0; s<sortedListSize; s++)
1894     {
1895         const U16 symbol = sortedList[s].symbol;
1896         const U32 weight = sortedList[s].weight;
1897         const U32 nbBits = nbBitsBaseline - weight;
1898         const U32 start = rankVal[weight];
1899         const U32 length = 1 << (targetLog-nbBits);
1900 
1901         if (targetLog-nbBits >= minBits)   /* enough room for a second symbol */
1902         {
1903             U32 sortedRank;
1904             int minWeight = nbBits + scaleLog;
1905             if (minWeight < 1) minWeight = 1;
1906             sortedRank = rankStart[minWeight];
1907             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
1908                            rankValOrigin[nbBits], minWeight,
1909                            sortedList+sortedRank, sortedListSize-sortedRank,
1910                            nbBitsBaseline, symbol);
1911         }
1912         else
1913         {
1914             U32 i;
1915             const U32 end = start + length;
1916             HUF_DEltX4 DElt;
1917 
1918             MEM_writeLE16(&(DElt.sequence), symbol);
1919             DElt.nbBits   = (BYTE)(nbBits);
1920             DElt.length   = 1;
1921             for (i = start; i < end; i++)
1922                 DTable[i] = DElt;
1923         }
1924         rankVal[weight] += length;
1925     }
1926 }
1927 
1928 static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
1929 {
1930     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
1931     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
1932     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
1933     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
1934     U32* const rankStart = rankStart0+1;
1935     rankVal_t rankVal;
1936     U32 tableLog, maxW, sizeOfSort, nbSymbols;
1937     const U32 memLog = DTable[0];
1938     const BYTE* ip = (const BYTE*) src;
1939     size_t iSize = ip[0];
1940     void* ptr = DTable;
1941     HUF_DEltX4* const dt = ((HUF_DEltX4*)ptr) + 1;
1942 
1943     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
1944     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
1945     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
1946 
1947     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
1948     if (HUF_isError(iSize)) return iSize;
1949 
1950     /* check result */
1951     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
1952 
1953     /* find maxWeight */
1954     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
1955         { if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
1956 
1957     /* Get start index of each weight */
1958     {
1959         U32 w, nextRankStart = 0;
1960         for (w=1; w<=maxW; w++)
1961         {
1962             U32 current = nextRankStart;
1963             nextRankStart += rankStats[w];
1964             rankStart[w] = current;
1965         }
1966         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
1967         sizeOfSort = nextRankStart;
1968     }
1969 
1970     /* sort symbols by weight */
1971     {
1972         U32 s;
1973         for (s=0; s<nbSymbols; s++)
1974         {
1975             U32 w = weightList[s];
1976             U32 r = rankStart[w]++;
1977             sortedSymbol[r].symbol = (BYTE)s;
1978             sortedSymbol[r].weight = (BYTE)w;
1979         }
1980         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
1981     }
1982 
1983     /* Build rankVal */
1984     {
1985         const U32 minBits = tableLog+1 - maxW;
1986         U32 nextRankVal = 0;
1987         U32 w, consumed;
1988         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
1989         U32* rankVal0 = rankVal[0];
1990         for (w=1; w<=maxW; w++)
1991         {
1992             U32 current = nextRankVal;
1993             nextRankVal += rankStats[w] << (w+rescale);
1994             rankVal0[w] = current;
1995         }
1996         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
1997         {
1998             U32* rankValPtr = rankVal[consumed];
1999             for (w = 1; w <= maxW; w++)
2000             {
2001                 rankValPtr[w] = rankVal0[w] >> consumed;
2002             }
2003         }
2004     }
2005 
2006     HUF_fillDTableX4(dt, memLog,
2007                    sortedSymbol, sizeOfSort,
2008                    rankStart0, rankVal, maxW,
2009                    tableLog+1);
2010 
2011     return iSize;
2012 }
2013 
2014 
2015 static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2016 {
2017     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2018     memcpy(op, dt+val, 2);
2019     BIT_skipBits(DStream, dt[val].nbBits);
2020     return dt[val].length;
2021 }
2022 
2023 static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2024 {
2025     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2026     memcpy(op, dt+val, 1);
2027     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
2028     else
2029     {
2030         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
2031         {
2032             BIT_skipBits(DStream, dt[val].nbBits);
2033             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2034                 DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);   /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
2035         }
2036     }
2037     return 1;
2038 }
2039 
2040 
2041 #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
2042     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2043 
2044 #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
2045     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
2046         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2047 
2048 #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
2049     if (MEM_64bits()) \
2050         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2051 
2052 static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
2053 {
2054     BYTE* const pStart = p;
2055 
2056     /* up to 8 symbols at a time */
2057     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
2058     {
2059         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2060         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
2061         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2062         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2063     }
2064 
2065     /* closer to the end */
2066     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
2067         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2068 
2069     while (p <= pEnd-2)
2070         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2071 
2072     if (p < pEnd)
2073         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
2074 
2075     return p-pStart;
2076 }
2077 
2078 
2079 
2080 static size_t HUF_decompress4X4_usingDTable(
2081           void* dst,  size_t dstSize,
2082     const void* cSrc, size_t cSrcSize,
2083     const U32* DTable)
2084 {
2085     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2086 
2087     {
2088         const BYTE* const istart = (const BYTE*) cSrc;
2089         BYTE* const ostart = (BYTE*) dst;
2090         BYTE* const oend = ostart + dstSize;
2091 
2092         const void* ptr = DTable;
2093         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)ptr) +1;
2094         const U32 dtLog = DTable[0];
2095         size_t errorCode;
2096 
2097         /* Init */
2098         BIT_DStream_t bitD1;
2099         BIT_DStream_t bitD2;
2100         BIT_DStream_t bitD3;
2101         BIT_DStream_t bitD4;
2102         const size_t length1 = MEM_readLE16(istart);
2103         const size_t length2 = MEM_readLE16(istart+2);
2104         const size_t length3 = MEM_readLE16(istart+4);
2105         size_t length4;
2106         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2107         const BYTE* const istart2 = istart1 + length1;
2108         const BYTE* const istart3 = istart2 + length2;
2109         const BYTE* const istart4 = istart3 + length3;
2110         const size_t segmentSize = (dstSize+3) / 4;
2111         BYTE* const opStart2 = ostart + segmentSize;
2112         BYTE* const opStart3 = opStart2 + segmentSize;
2113         BYTE* const opStart4 = opStart3 + segmentSize;
2114         BYTE* op1 = ostart;
2115         BYTE* op2 = opStart2;
2116         BYTE* op3 = opStart3;
2117         BYTE* op4 = opStart4;
2118         U32 endSignal;
2119 
2120         length4 = cSrcSize - (length1 + length2 + length3 + 6);
2121         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2122         errorCode = BIT_initDStream(&bitD1, istart1, length1);
2123         if (HUF_isError(errorCode)) return errorCode;
2124         errorCode = BIT_initDStream(&bitD2, istart2, length2);
2125         if (HUF_isError(errorCode)) return errorCode;
2126         errorCode = BIT_initDStream(&bitD3, istart3, length3);
2127         if (HUF_isError(errorCode)) return errorCode;
2128         errorCode = BIT_initDStream(&bitD4, istart4, length4);
2129         if (HUF_isError(errorCode)) return errorCode;
2130 
2131         /* 16-32 symbols per loop (4-8 symbols per stream) */
2132         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2133         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
2134         {
2135             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2136             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2137             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2138             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2139             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
2140             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
2141             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
2142             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
2143             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2144             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2145             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2146             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2147             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
2148             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
2149             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
2150             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
2151 
2152             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2153         }
2154 
2155         /* check corruption */
2156         if (op1 > opStart2) return ERROR(corruption_detected);
2157         if (op2 > opStart3) return ERROR(corruption_detected);
2158         if (op3 > opStart4) return ERROR(corruption_detected);
2159         /* note : op4 supposed already verified within main loop */
2160 
2161         /* finish bitStreams one by one */
2162         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
2163         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
2164         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
2165         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
2166 
2167         /* check */
2168         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
2169         if (!endSignal) return ERROR(corruption_detected);
2170 
2171         /* decoded size */
2172         return dstSize;
2173     }
2174 }
2175 
2176 
2177 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2178 {
2179     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
2180     const BYTE* ip = (const BYTE*) cSrc;
2181 
2182     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
2183     if (HUF_isError(hSize)) return hSize;
2184     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2185     ip += hSize;
2186     cSrcSize -= hSize;
2187 
2188     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
2189 }
2190 
2191 
2192 /**********************************/
2193 /* Generic decompression selector */
2194 /**********************************/
2195 
2196 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
2197 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
2198 {
2199     /* single, double, quad */
2200     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
2201     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
2202     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
2203     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
2204     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
2205     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
2206     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
2207     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
2208     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
2209     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
2210     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
2211     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
2212     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
2213     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
2214     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
2215     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
2216 };
2217 
2218 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
2219 
2220 static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2221 {
2222     static const decompressionAlgo decompress[3] = { HUF_decompress4X2, HUF_decompress4X4, NULL };
2223     /* estimate decompression time */
2224     U32 Q;
2225     const U32 D256 = (U32)(dstSize >> 8);
2226     U32 Dtime[3];
2227     U32 algoNb = 0;
2228     int n;
2229 
2230     /* validation checks */
2231     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2232     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2233     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2234     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2235 
2236     /* decoder timing evaluation */
2237     Q = (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 since dstSize > cSrcSize */
2238     for (n=0; n<3; n++)
2239         Dtime[n] = algoTime[Q][n].tableTime + (algoTime[Q][n].decode256Time * D256);
2240 
2241     Dtime[1] += Dtime[1] >> 4; Dtime[2] += Dtime[2] >> 3; /* advantage to algorithms using less memory, for cache eviction */
2242 
2243     if (Dtime[1] < Dtime[0]) algoNb = 1;
2244 
2245     return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
2246 
2247     //return HUF_decompress4X2(dst, dstSize, cSrc, cSrcSize);   /* multi-streams single-symbol decoding */
2248     //return HUF_decompress4X4(dst, dstSize, cSrc, cSrcSize);   /* multi-streams double-symbols decoding */
2249     //return HUF_decompress4X6(dst, dstSize, cSrc, cSrcSize);   /* multi-streams quad-symbols decoding */
2250 }
2251 /*
2252     zstd - standard compression library
2253     Copyright (C) 2014-2015, Yann Collet.
2254 
2255     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2256 
2257     Redistribution and use in source and binary forms, with or without
2258     modification, are permitted provided that the following conditions are
2259     met:
2260     * Redistributions of source code must retain the above copyright
2261     notice, this list of conditions and the following disclaimer.
2262     * Redistributions in binary form must reproduce the above
2263     copyright notice, this list of conditions and the following disclaimer
2264     in the documentation and/or other materials provided with the
2265     distribution.
2266     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2267     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2268     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2269     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2270     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2271     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2272     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2273     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2274     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2275     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2276     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2277 
2278     You can contact the author at :
2279     - zstd source repository : https://github.com/Cyan4973/zstd
2280     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
2281 */
2282 
2283 /* ***************************************************************
2284 *  Tuning parameters
2285 *****************************************************************/
2286 /*!
2287 *  MEMORY_USAGE :
2288 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
2289 *  Increasing memory usage improves compression ratio
2290 *  Reduced memory usage can improve speed, due to cache effect
2291 */
2292 #define ZSTD_MEMORY_USAGE 17
2293 
2294 /*!
2295  * HEAPMODE :
2296  * Select how default compression functions will allocate memory for their hash table,
2297  * in memory stack (0, fastest), or in memory heap (1, requires malloc())
2298  * Note that compression context is fairly large, as a consequence heap memory is recommended.
2299  */
2300 #ifndef ZSTD_HEAPMODE
2301 #  define ZSTD_HEAPMODE 1
2302 #endif /* ZSTD_HEAPMODE */
2303 
2304 /*!
2305 *  LEGACY_SUPPORT :
2306 *  decompressor can decode older formats (starting from Zstd 0.1+)
2307 */
2308 #ifndef ZSTD_LEGACY_SUPPORT
2309 #  define ZSTD_LEGACY_SUPPORT 1
2310 #endif
2311 
2312 
2313 /* *******************************************************
2314 *  Includes
2315 *********************************************************/
2316 #include <stdlib.h>      /* calloc */
2317 #include <string.h>      /* memcpy, memmove */
2318 #include <stdio.h>       /* debug : printf */
2319 
2320 
2321 /* *******************************************************
2322 *  Compiler specifics
2323 *********************************************************/
2324 #ifdef __AVX2__
2325 #  include <immintrin.h>   /* AVX2 intrinsics */
2326 #endif
2327 
2328 #ifdef _MSC_VER    /* Visual Studio */
2329 #  include <intrin.h>                    /* For Visual 2005 */
2330 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
2331 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
2332 #else
2333 #  define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
2334 #endif
2335 
2336 
2337 /* *******************************************************
2338 *  Constants
2339 *********************************************************/
2340 #define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
2341 #define HASH_TABLESIZE (1 << HASH_LOG)
2342 #define HASH_MASK (HASH_TABLESIZE - 1)
2343 
2344 #define KNUTH 2654435761
2345 
2346 #define BIT7 128
2347 #define BIT6  64
2348 #define BIT5  32
2349 #define BIT4  16
2350 #define BIT1   2
2351 #define BIT0   1
2352 
2353 #define KB *(1 <<10)
2354 #define MB *(1 <<20)
2355 #define GB *(1U<<30)
2356 
2357 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
2358 #define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
2359 #define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
2360 #define IS_RAW BIT0
2361 #define IS_RLE BIT1
2362 
2363 #define WORKPLACESIZE (BLOCKSIZE*3)
2364 #define MINMATCH 4
2365 #define MLbits   7
2366 #define LLbits   6
2367 #define Offbits  5
2368 #define MaxML  ((1<<MLbits )-1)
2369 #define MaxLL  ((1<<LLbits )-1)
2370 #define MaxOff   31
2371 #define LitFSELog  11
2372 #define MLFSELog   10
2373 #define LLFSELog   10
2374 #define OffFSELog   9
2375 #define MAX(a,b) ((a)<(b)?(b):(a))
2376 #define MaxSeq MAX(MaxLL, MaxML)
2377 
2378 #define LITERAL_NOENTROPY 63
2379 #define COMMAND_NOENTROPY 7   /* to remove */
2380 
2381 #define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
2382 
2383 static const size_t ZSTD_blockHeaderSize = 3;
2384 static const size_t ZSTD_frameHeaderSize = 4;
2385 
2386 
2387 /* *******************************************************
2388 *  Memory operations
2389 **********************************************************/
2390 static void   ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
2391 
2392 static void   ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
2393 
2394 #define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }
2395 
2396 /*! ZSTD_wildcopy : custom version of memcpy(), can copy up to 7-8 bytes too many */
2397 static void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length)
2398 {
2399     const BYTE* ip = (const BYTE*)src;
2400     BYTE* op = (BYTE*)dst;
2401     BYTE* const oend = op + length;
2402     do COPY8(op, ip) while (op < oend);
2403 }
2404 
2405 
2406 /* **************************************
2407 *  Local structures
2408 ****************************************/
2409 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
2410 
2411 typedef struct
2412 {
2413     blockType_t blockType;
2414     U32 origSize;
2415 } blockProperties_t;
2416 
2417 typedef struct {
2418     void* buffer;
2419     U32*  offsetStart;
2420     U32*  offset;
2421     BYTE* offCodeStart;
2422     BYTE* offCode;
2423     BYTE* litStart;
2424     BYTE* lit;
2425     BYTE* litLengthStart;
2426     BYTE* litLength;
2427     BYTE* matchLengthStart;
2428     BYTE* matchLength;
2429     BYTE* dumpsStart;
2430     BYTE* dumps;
2431 } seqStore_t;
2432 
2433 
2434 /* *************************************
2435 *  Error Management
2436 ***************************************/
2437 /*! ZSTD_isError
2438 *   tells if a return value is an error code */
2439 static unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
2440 
2441 
2442 
2443 /* *************************************************************
2444 *   Decompression section
2445 ***************************************************************/
2446 struct ZSTD_DCtx_s
2447 {
2448     U32 LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
2449     U32 OffTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
2450     U32 MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
2451     void* previousDstEnd;
2452     void* base;
2453     size_t expected;
2454     blockType_t bType;
2455     U32 phase;
2456     const BYTE* litPtr;
2457     size_t litSize;
2458     BYTE litBuffer[BLOCKSIZE + 8 /* margin for wildcopy */];
2459 };   /* typedef'd to ZSTD_Dctx within "zstd_static.h" */
2460 
2461 
2462 static size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
2463 {
2464     const BYTE* const in = (const BYTE* const)src;
2465     BYTE headerFlags;
2466     U32 cSize;
2467 
2468     if (srcSize < 3) return ERROR(srcSize_wrong);
2469 
2470     headerFlags = *in;
2471     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
2472 
2473     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
2474     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
2475 
2476     if (bpPtr->blockType == bt_end) return 0;
2477     if (bpPtr->blockType == bt_rle) return 1;
2478     return cSize;
2479 }
2480 
2481 static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
2482 {
2483     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
2484     if (srcSize > 0) {
2485         memcpy(dst, src, srcSize);
2486     }
2487     return srcSize;
2488 }
2489 
2490 
2491 /** ZSTD_decompressLiterals
2492     @return : nb of bytes read from src, or an error code*/
2493 static size_t ZSTD_decompressLiterals(void* dst, size_t* maxDstSizePtr,
2494                                 const void* src, size_t srcSize)
2495 {
2496     const BYTE* ip = (const BYTE*)src;
2497 
2498     const size_t litSize = (MEM_readLE32(src) & 0x1FFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2499     const size_t litCSize = (MEM_readLE32(ip+2) & 0xFFFFFF) >> 5;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2500 
2501     if (litSize > *maxDstSizePtr) return ERROR(corruption_detected);
2502     if (litCSize + 5 > srcSize) return ERROR(corruption_detected);
2503 
2504     if (HUF_isError(HUF_decompress(dst, litSize, ip+5, litCSize))) return ERROR(corruption_detected);
2505 
2506     *maxDstSizePtr = litSize;
2507     return litCSize + 5;
2508 }
2509 
2510 
2511 /** ZSTD_decodeLiteralsBlock
2512     @return : nb of bytes read from src (< srcSize )*/
2513 static size_t ZSTD_decodeLiteralsBlock(void* ctx,
2514                           const void* src, size_t srcSize)
2515 {
2516     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
2517     const BYTE* const istart = (const BYTE* const)src;
2518 
2519     /* any compressed block with literals segment must be at least this size */
2520     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
2521 
2522     switch(*istart & 3)
2523     {
2524     default:
2525     case 0:
2526         {
2527             size_t litSize = BLOCKSIZE;
2528             const size_t readSize = ZSTD_decompressLiterals(dctx->litBuffer, &litSize, src, srcSize);
2529             dctx->litPtr = dctx->litBuffer;
2530             dctx->litSize = litSize;
2531             memset(dctx->litBuffer + dctx->litSize, 0, 8);
2532             return readSize;   /* works if it's an error too */
2533         }
2534     case IS_RAW:
2535         {
2536             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2537             if (litSize > srcSize-11)   /* risk of reading too far with wildcopy */
2538             {
2539                 if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2540                 if (litSize > srcSize-3) return ERROR(corruption_detected);
2541                 memcpy(dctx->litBuffer, istart, litSize);
2542                 dctx->litPtr = dctx->litBuffer;
2543                 dctx->litSize = litSize;
2544                 memset(dctx->litBuffer + dctx->litSize, 0, 8);
2545                 return litSize+3;
2546             }
2547             /* direct reference into compressed stream */
2548             dctx->litPtr = istart+3;
2549             dctx->litSize = litSize;
2550             return litSize+3;
2551         }
2552     case IS_RLE:
2553         {
2554             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2555             if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2556             memset(dctx->litBuffer, istart[3], litSize + 8);
2557             dctx->litPtr = dctx->litBuffer;
2558             dctx->litSize = litSize;
2559             return 4;
2560         }
2561     }
2562 }
2563 
2564 
2565 static size_t ZSTD_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
2566                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
2567                          const void* src, size_t srcSize)
2568 {
2569     const BYTE* const istart = (const BYTE* const)src;
2570     const BYTE* ip = istart;
2571     const BYTE* const iend = istart + srcSize;
2572     U32 LLtype, Offtype, MLtype;
2573     U32 LLlog, Offlog, MLlog;
2574     size_t dumpsLength;
2575 
2576     /* check */
2577     if (srcSize < 5) return ERROR(srcSize_wrong);
2578 
2579     /* SeqHead */
2580     *nbSeq = MEM_readLE16(ip); ip+=2;
2581     LLtype  = *ip >> 6;
2582     Offtype = (*ip >> 4) & 3;
2583     MLtype  = (*ip >> 2) & 3;
2584     if (*ip & 2)
2585     {
2586         dumpsLength  = ip[2];
2587         dumpsLength += ip[1] << 8;
2588         ip += 3;
2589     }
2590     else
2591     {
2592         dumpsLength  = ip[1];
2593         dumpsLength += (ip[0] & 1) << 8;
2594         ip += 2;
2595     }
2596     *dumpsPtr = ip;
2597     ip += dumpsLength;
2598     *dumpsLengthPtr = dumpsLength;
2599 
2600     /* check */
2601     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
2602 
2603     /* sequences */
2604     {
2605         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL and MaxOff */
2606         size_t headerSize;
2607 
2608         /* Build DTables */
2609         switch(LLtype)
2610         {
2611         case bt_rle :
2612             LLlog = 0;
2613             FSE_buildDTable_rle(DTableLL, *ip++); break;
2614         case bt_raw :
2615             LLlog = LLbits;
2616             FSE_buildDTable_raw(DTableLL, LLbits); break;
2617         default :
2618             {   U32 max = MaxLL;
2619                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
2620                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2621                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
2622                 ip += headerSize;
2623                 FSE_buildDTable(DTableLL, norm, max, LLlog);
2624         }   }
2625 
2626         switch(Offtype)
2627         {
2628         case bt_rle :
2629             Offlog = 0;
2630             if (ip > iend-2) return ERROR(srcSize_wrong);   /* min : "raw", hence no header, but at least xxLog bits */
2631             FSE_buildDTable_rle(DTableOffb, *ip++ & MaxOff); /* if *ip > MaxOff, data is corrupted */
2632             break;
2633         case bt_raw :
2634             Offlog = Offbits;
2635             FSE_buildDTable_raw(DTableOffb, Offbits); break;
2636         default :
2637             {   U32 max = MaxOff;
2638                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
2639                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2640                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
2641                 ip += headerSize;
2642                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
2643         }   }
2644 
2645         switch(MLtype)
2646         {
2647         case bt_rle :
2648             MLlog = 0;
2649             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
2650             FSE_buildDTable_rle(DTableML, *ip++); break;
2651         case bt_raw :
2652             MLlog = MLbits;
2653             FSE_buildDTable_raw(DTableML, MLbits); break;
2654         default :
2655             {   U32 max = MaxML;
2656                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
2657                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2658                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
2659                 ip += headerSize;
2660                 FSE_buildDTable(DTableML, norm, max, MLlog);
2661     }   }   }
2662 
2663     return ip-istart;
2664 }
2665 
2666 
2667 typedef struct {
2668     size_t litLength;
2669     size_t offset;
2670     size_t matchLength;
2671 } seq_t;
2672 
2673 typedef struct {
2674     BIT_DStream_t DStream;
2675     FSE_DState_t stateLL;
2676     FSE_DState_t stateOffb;
2677     FSE_DState_t stateML;
2678     size_t prevOffset;
2679     const BYTE* dumps;
2680     const BYTE* dumpsEnd;
2681 } seqState_t;
2682 
2683 
2684 static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
2685 {
2686     size_t litLength;
2687     size_t prevOffset;
2688     size_t offset;
2689     size_t matchLength;
2690     const BYTE* dumps = seqState->dumps;
2691     const BYTE* const de = seqState->dumpsEnd;
2692 
2693     /* Literal length */
2694     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
2695     prevOffset = litLength ? seq->offset : seqState->prevOffset;
2696     seqState->prevOffset = seq->offset;
2697     if (litLength == MaxLL)
2698     {
2699         const U32 add = dumps<de ? *dumps++ : 0;
2700         if (add < 255) litLength += add;
2701         else if (dumps + 3 <= de)
2702         {
2703             litLength = MEM_readLE24(dumps);
2704             dumps += 3;
2705         }
2706         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
2707     }
2708 
2709     /* Offset */
2710     {
2711         static const size_t offsetPrefix[MaxOff+1] = {  /* note : size_t faster than U32 */
2712                 1 /*fake*/, 1, 2, 4, 8, 16, 32, 64, 128, 256,
2713                 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144,
2714                 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, /*fake*/ 1, 1, 1, 1, 1 };
2715         U32 offsetCode, nbBits;
2716         offsetCode = FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream));   /* <= maxOff, by table construction */
2717         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
2718         nbBits = offsetCode - 1;
2719         if (offsetCode==0) nbBits = 0;   /* cmove */
2720         offset = offsetPrefix[offsetCode] + BIT_readBits(&(seqState->DStream), nbBits);
2721         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
2722         if (offsetCode==0) offset = prevOffset;   /* cmove */
2723     }
2724 
2725     /* MatchLength */
2726     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
2727     if (matchLength == MaxML)
2728     {
2729         const U32 add = dumps<de ? *dumps++ : 0;
2730         if (add < 255) matchLength += add;
2731         else if (dumps + 3 <= de)
2732         {
2733             matchLength = MEM_readLE24(dumps);
2734             dumps += 3;
2735         }
2736         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
2737     }
2738     matchLength += MINMATCH;
2739 
2740     /* save result */
2741     seq->litLength = litLength;
2742     seq->offset = offset;
2743     seq->matchLength = matchLength;
2744     seqState->dumps = dumps;
2745 }
2746 
2747 
2748 static size_t ZSTD_execSequence(BYTE* op,
2749                                 seq_t sequence,
2750                                 const BYTE** litPtr, const BYTE* const litLimit,
2751                                 BYTE* const base, BYTE* const oend)
2752 {
2753     static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
2754     static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11};   /* subtracted */
2755     const BYTE* const ostart = op;
2756     BYTE* const oLitEnd = op + sequence.litLength;
2757     BYTE* const oMatchEnd = op + sequence.litLength + sequence.matchLength;   /* risk : address space overflow (32-bits) */
2758     BYTE* const oend_8 = oend-8;
2759     const BYTE* const litEnd = *litPtr + sequence.litLength;
2760 
2761     /* checks */
2762     if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall);   /* last match must start at a minimum distance of 8 from oend */
2763     if (oMatchEnd > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
2764     if (litEnd > litLimit) return ERROR(corruption_detected);   /* overRead beyond lit buffer */
2765 
2766     /* copy Literals */
2767     ZSTD_wildcopy(op, *litPtr, sequence.litLength);   /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
2768     op = oLitEnd;
2769     *litPtr = litEnd;   /* update for next sequence */
2770 
2771     /* copy Match */
2772     {
2773         const BYTE* match = op - sequence.offset;
2774 
2775         /* check */
2776         if (sequence.offset > (size_t)op) return ERROR(corruption_detected);   /* address space overflow test (this test seems kept by clang optimizer) */
2777         //if (match > op) return ERROR(corruption_detected);   /* address space overflow test (is clang optimizer removing this test ?) */
2778         if (match < base) return ERROR(corruption_detected);
2779 
2780         /* close range match, overlap */
2781         if (sequence.offset < 8)
2782         {
2783             const int dec64 = dec64table[sequence.offset];
2784             op[0] = match[0];
2785             op[1] = match[1];
2786             op[2] = match[2];
2787             op[3] = match[3];
2788             match += dec32table[sequence.offset];
2789             ZSTD_copy4(op+4, match);
2790             match -= dec64;
2791         }
2792         else
2793         {
2794             ZSTD_copy8(op, match);
2795         }
2796         op += 8; match += 8;
2797 
2798         if (oMatchEnd > oend-(16-MINMATCH))
2799         {
2800             if (op < oend_8)
2801             {
2802                 ZSTD_wildcopy(op, match, oend_8 - op);
2803                 match += oend_8 - op;
2804                 op = oend_8;
2805             }
2806             while (op < oMatchEnd) *op++ = *match++;
2807         }
2808         else
2809         {
2810             ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
2811         }
2812     }
2813 
2814     return oMatchEnd - ostart;
2815 }
2816 
2817 static size_t ZSTD_decompressSequences(
2818                                void* ctx,
2819                                void* dst, size_t maxDstSize,
2820                          const void* seqStart, size_t seqSize)
2821 {
2822     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
2823     const BYTE* ip = (const BYTE*)seqStart;
2824     const BYTE* const iend = ip + seqSize;
2825     BYTE* const ostart = (BYTE* const)dst;
2826     BYTE* op = ostart;
2827     BYTE* const oend = ostart + maxDstSize;
2828     size_t errorCode, dumpsLength;
2829     const BYTE* litPtr = dctx->litPtr;
2830     const BYTE* const litEnd = litPtr + dctx->litSize;
2831     int nbSeq;
2832     const BYTE* dumps;
2833     U32* DTableLL = dctx->LLTable;
2834     U32* DTableML = dctx->MLTable;
2835     U32* DTableOffb = dctx->OffTable;
2836     BYTE* const base = (BYTE*) (dctx->base);
2837 
2838     /* Build Decoding Tables */
2839     errorCode = ZSTD_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
2840                                       DTableLL, DTableML, DTableOffb,
2841                                       ip, iend-ip);
2842     if (ZSTD_isError(errorCode)) return errorCode;
2843     ip += errorCode;
2844 
2845     /* Regen sequences */
2846     {
2847         seq_t sequence;
2848         seqState_t seqState;
2849 
2850         memset(&sequence, 0, sizeof(sequence));
2851         seqState.dumps = dumps;
2852         seqState.dumpsEnd = dumps + dumpsLength;
2853         seqState.prevOffset = sequence.offset = 4;
2854         errorCode = BIT_initDStream(&(seqState.DStream), ip, iend-ip);
2855         if (ERR_isError(errorCode)) return ERROR(corruption_detected);
2856         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
2857         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
2858         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
2859 
2860         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (nbSeq>0) ; )
2861         {
2862             size_t oneSeqSize;
2863             nbSeq--;
2864             ZSTD_decodeSequence(&sequence, &seqState);
2865             oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend);
2866             if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
2867             op += oneSeqSize;
2868         }
2869 
2870         /* check if reached exact end */
2871         if ( !BIT_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* requested too much : data is corrupted */
2872         if (nbSeq<0) return ERROR(corruption_detected);   /* requested too many sequences : data is corrupted */
2873 
2874         /* last literal segment */
2875         {
2876             size_t lastLLSize = litEnd - litPtr;
2877             if (litPtr > litEnd) return ERROR(corruption_detected);
2878             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
2879             if (lastLLSize > 0) {
2880                 if (op != litPtr) memmove(op, litPtr, lastLLSize);
2881                 op += lastLLSize;
2882             }
2883         }
2884     }
2885 
2886     return op-ostart;
2887 }
2888 
2889 
2890 static size_t ZSTD_decompressBlock(
2891                             void* ctx,
2892                             void* dst, size_t maxDstSize,
2893                       const void* src, size_t srcSize)
2894 {
2895     /* blockType == blockCompressed */
2896     const BYTE* ip = (const BYTE*)src;
2897 
2898     /* Decode literals sub-block */
2899     size_t litCSize = ZSTD_decodeLiteralsBlock(ctx, src, srcSize);
2900     if (ZSTD_isError(litCSize)) return litCSize;
2901     ip += litCSize;
2902     srcSize -= litCSize;
2903 
2904     return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize);
2905 }
2906 
2907 
2908 static size_t ZSTD_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
2909 {
2910     const BYTE* ip = (const BYTE*)src;
2911     const BYTE* iend = ip + srcSize;
2912     BYTE* const ostart = (BYTE* const)dst;
2913     BYTE* op = ostart;
2914     BYTE* const oend = ostart + maxDstSize;
2915     size_t remainingSize = srcSize;
2916     U32 magicNumber;
2917     blockProperties_t blockProperties;
2918 
2919     /* Frame Header */
2920     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
2921     magicNumber = MEM_readLE32(src);
2922     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
2923     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
2924 
2925     /* Loop on each block */
2926     while (1)
2927     {
2928         size_t decodedSize=0;
2929         size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &blockProperties);
2930         if (ZSTD_isError(cBlockSize)) return cBlockSize;
2931 
2932         ip += ZSTD_blockHeaderSize;
2933         remainingSize -= ZSTD_blockHeaderSize;
2934         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
2935 
2936         switch(blockProperties.blockType)
2937         {
2938         case bt_compressed:
2939             decodedSize = ZSTD_decompressBlock(ctx, op, oend-op, ip, cBlockSize);
2940             break;
2941         case bt_raw :
2942             decodedSize = ZSTD_copyUncompressedBlock(op, oend-op, ip, cBlockSize);
2943             break;
2944         case bt_rle :
2945             return ERROR(GENERIC);   /* not yet supported */
2946             break;
2947         case bt_end :
2948             /* end of frame */
2949             if (remainingSize) return ERROR(srcSize_wrong);
2950             break;
2951         default:
2952             return ERROR(GENERIC);   /* impossible */
2953         }
2954         if (cBlockSize == 0) break;   /* bt_end */
2955 
2956         if (ZSTD_isError(decodedSize)) return decodedSize;
2957         op += decodedSize;
2958         ip += cBlockSize;
2959         remainingSize -= cBlockSize;
2960     }
2961 
2962     return op-ostart;
2963 }
2964 
2965 static size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
2966 {
2967     ZSTD_DCtx ctx;
2968     ctx.base = dst;
2969     return ZSTD_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
2970 }
2971 
2972 /* ZSTD_errorFrameSizeInfoLegacy() :
2973    assumes `cSize` and `dBound` are _not_ NULL */
2974 MEM_STATIC void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
2975 {
2976     *cSize = ret;
2977     *dBound = ZSTD_CONTENTSIZE_ERROR;
2978 }
2979 
2980 void ZSTDv03_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
2981 {
2982     const BYTE* ip = (const BYTE*)src;
2983     size_t remainingSize = srcSize;
2984     size_t nbBlocks = 0;
2985     U32 magicNumber;
2986     blockProperties_t blockProperties;
2987 
2988     /* Frame Header */
2989     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) {
2990         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
2991         return;
2992     }
2993     magicNumber = MEM_readLE32(src);
2994     if (magicNumber != ZSTD_magicNumber) {
2995         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
2996         return;
2997     }
2998     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
2999 
3000     /* Loop on each block */
3001     while (1)
3002     {
3003         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
3004         if (ZSTD_isError(cBlockSize)) {
3005             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
3006             return;
3007         }
3008 
3009         ip += ZSTD_blockHeaderSize;
3010         remainingSize -= ZSTD_blockHeaderSize;
3011         if (cBlockSize > remainingSize) {
3012             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3013             return;
3014         }
3015 
3016         if (cBlockSize == 0) break;   /* bt_end */
3017 
3018         ip += cBlockSize;
3019         remainingSize -= cBlockSize;
3020         nbBlocks++;
3021     }
3022 
3023     *cSize = ip - (const BYTE*)src;
3024     *dBound = nbBlocks * BLOCKSIZE;
3025 }
3026 
3027 
3028 /*******************************
3029 *  Streaming Decompression API
3030 *******************************/
3031 
3032 static size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx)
3033 {
3034     dctx->expected = ZSTD_frameHeaderSize;
3035     dctx->phase = 0;
3036     dctx->previousDstEnd = NULL;
3037     dctx->base = NULL;
3038     return 0;
3039 }
3040 
3041 static ZSTD_DCtx* ZSTD_createDCtx(void)
3042 {
3043     ZSTD_DCtx* dctx = (ZSTD_DCtx*)malloc(sizeof(ZSTD_DCtx));
3044     if (dctx==NULL) return NULL;
3045     ZSTD_resetDCtx(dctx);
3046     return dctx;
3047 }
3048 
3049 static size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
3050 {
3051     free(dctx);
3052     return 0;
3053 }
3054 
3055 static size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx)
3056 {
3057     return dctx->expected;
3058 }
3059 
3060 static size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3061 {
3062     /* Sanity check */
3063     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
3064     if (dst != ctx->previousDstEnd)  /* not contiguous */
3065         ctx->base = dst;
3066 
3067     /* Decompress : frame header */
3068     if (ctx->phase == 0)
3069     {
3070         /* Check frame magic header */
3071         U32 magicNumber = MEM_readLE32(src);
3072         if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
3073         ctx->phase = 1;
3074         ctx->expected = ZSTD_blockHeaderSize;
3075         return 0;
3076     }
3077 
3078     /* Decompress : block header */
3079     if (ctx->phase == 1)
3080     {
3081         blockProperties_t bp;
3082         size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
3083         if (ZSTD_isError(blockSize)) return blockSize;
3084         if (bp.blockType == bt_end)
3085         {
3086             ctx->expected = 0;
3087             ctx->phase = 0;
3088         }
3089         else
3090         {
3091             ctx->expected = blockSize;
3092             ctx->bType = bp.blockType;
3093             ctx->phase = 2;
3094         }
3095 
3096         return 0;
3097     }
3098 
3099     /* Decompress : block content */
3100     {
3101         size_t rSize;
3102         switch(ctx->bType)
3103         {
3104         case bt_compressed:
3105             rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
3106             break;
3107         case bt_raw :
3108             rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize);
3109             break;
3110         case bt_rle :
3111             return ERROR(GENERIC);   /* not yet handled */
3112             break;
3113         case bt_end :   /* should never happen (filtered at phase 1) */
3114             rSize = 0;
3115             break;
3116         default:
3117             return ERROR(GENERIC);
3118         }
3119         ctx->phase = 1;
3120         ctx->expected = ZSTD_blockHeaderSize;
3121         ctx->previousDstEnd = (void*)( ((char*)dst) + rSize);
3122         return rSize;
3123     }
3124 
3125 }
3126 
3127 
3128 /* wrapper layer */
3129 
3130 unsigned ZSTDv03_isError(size_t code)
3131 {
3132     return ZSTD_isError(code);
3133 }
3134 
3135 size_t ZSTDv03_decompress( void* dst, size_t maxOriginalSize,
3136                      const void* src, size_t compressedSize)
3137 {
3138     return ZSTD_decompress(dst, maxOriginalSize, src, compressedSize);
3139 }
3140 
3141 ZSTDv03_Dctx* ZSTDv03_createDCtx(void)
3142 {
3143     return (ZSTDv03_Dctx*)ZSTD_createDCtx();
3144 }
3145 
3146 size_t ZSTDv03_freeDCtx(ZSTDv03_Dctx* dctx)
3147 {
3148     return ZSTD_freeDCtx((ZSTD_DCtx*)dctx);
3149 }
3150 
3151 size_t ZSTDv03_resetDCtx(ZSTDv03_Dctx* dctx)
3152 {
3153     return ZSTD_resetDCtx((ZSTD_DCtx*)dctx);
3154 }
3155 
3156 size_t ZSTDv03_nextSrcSizeToDecompress(ZSTDv03_Dctx* dctx)
3157 {
3158     return ZSTD_nextSrcSizeToDecompress((ZSTD_DCtx*)dctx);
3159 }
3160 
3161 size_t ZSTDv03_decompressContinue(ZSTDv03_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3162 {
3163     return ZSTD_decompressContinue((ZSTD_DCtx*)dctx, dst, maxDstSize, src, srcSize);
3164 }
3165