xref: /freebsd/sys/contrib/zstd/lib/legacy/zstd_v02.c (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*
2  * Copyright (c) 2016-present, 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_v02.h"
14 #include "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    mem.h
28    low-level memory access routines
29    Copyright (C) 2013-2015, Yann Collet.
30 
31    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
32 
33    Redistribution and use in source and binary forms, with or without
34    modification, are permitted provided that the following conditions are
35    met:
36 
37        * Redistributions of source code must retain the above copyright
38    notice, this list of conditions and the following disclaimer.
39        * Redistributions in binary form must reproduce the above
40    copyright notice, this list of conditions and the following disclaimer
41    in the documentation and/or other materials provided with the
42    distribution.
43 
44    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
45    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
46    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
47    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
48    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
49    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
50    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
51    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
52    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
53    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
54    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
55 
56     You can contact the author at :
57     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
58     - Public forum : https://groups.google.com/forum/#!forum/lz4c
59 ****************************************************************** */
60 #ifndef MEM_H_MODULE
61 #define MEM_H_MODULE
62 
63 #if defined (__cplusplus)
64 extern "C" {
65 #endif
66 
67 /******************************************
68 *  Includes
69 ******************************************/
70 #include <stddef.h>    /* size_t, ptrdiff_t */
71 #include <string.h>    /* memcpy */
72 
73 
74 /******************************************
75 *  Compiler-specific
76 ******************************************/
77 #if defined(__GNUC__)
78 #  define MEM_STATIC static __attribute__((unused))
79 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
80 #  define MEM_STATIC static inline
81 #elif defined(_MSC_VER)
82 #  define MEM_STATIC static __inline
83 #else
84 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
85 #endif
86 
87 
88 /****************************************************************
89 *  Basic Types
90 *****************************************************************/
91 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
92 # include <stdint.h>
93   typedef  uint8_t BYTE;
94   typedef uint16_t U16;
95   typedef  int16_t S16;
96   typedef uint32_t U32;
97   typedef  int32_t S32;
98   typedef uint64_t U64;
99   typedef  int64_t S64;
100 #else
101   typedef unsigned char       BYTE;
102   typedef unsigned short      U16;
103   typedef   signed short      S16;
104   typedef unsigned int        U32;
105   typedef   signed int        S32;
106   typedef unsigned long long  U64;
107   typedef   signed long long  S64;
108 #endif
109 
110 
111 /****************************************************************
112 *  Memory I/O
113 *****************************************************************/
114 /* MEM_FORCE_MEMORY_ACCESS
115  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
116  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
117  * The below switch allow to select different access method for improved performance.
118  * Method 0 (default) : use `memcpy()`. Safe and portable.
119  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
120  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
121  * Method 2 : direct access. This method is portable but violate C standard.
122  *            It can generate buggy code on targets generating assembly depending on alignment.
123  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
124  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
125  * Prefer these methods in priority order (0 > 1 > 2)
126  */
127 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
128 #  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__) )
129 #    define MEM_FORCE_MEMORY_ACCESS 2
130 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
131   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
132 #    define MEM_FORCE_MEMORY_ACCESS 1
133 #  endif
134 #endif
135 
136 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
137 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
138 
139 MEM_STATIC unsigned MEM_isLittleEndian(void)
140 {
141     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
142     return one.c[0];
143 }
144 
145 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
146 
147 /* violates C standard on structure alignment.
148 Only use if no other choice to achieve best performance on target platform */
149 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
150 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
151 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
152 
153 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
154 
155 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
156 
157 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
158 /* currently only defined for gcc and icc */
159 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
160 
161 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
162 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
163 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
164 
165 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
166 
167 #else
168 
169 /* default method, safe and standard.
170    can sometimes prove slower */
171 
172 MEM_STATIC U16 MEM_read16(const void* memPtr)
173 {
174     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
175 }
176 
177 MEM_STATIC U32 MEM_read32(const void* memPtr)
178 {
179     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
180 }
181 
182 MEM_STATIC U64 MEM_read64(const void* memPtr)
183 {
184     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
185 }
186 
187 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
188 {
189     memcpy(memPtr, &value, sizeof(value));
190 }
191 
192 #endif // MEM_FORCE_MEMORY_ACCESS
193 
194 
195 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
196 {
197     if (MEM_isLittleEndian())
198         return MEM_read16(memPtr);
199     else
200     {
201         const BYTE* p = (const BYTE*)memPtr;
202         return (U16)(p[0] + (p[1]<<8));
203     }
204 }
205 
206 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
207 {
208     if (MEM_isLittleEndian())
209     {
210         MEM_write16(memPtr, val);
211     }
212     else
213     {
214         BYTE* p = (BYTE*)memPtr;
215         p[0] = (BYTE)val;
216         p[1] = (BYTE)(val>>8);
217     }
218 }
219 
220 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
221 {
222     if (MEM_isLittleEndian())
223         return MEM_read32(memPtr);
224     else
225     {
226         const BYTE* p = (const BYTE*)memPtr;
227         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
228     }
229 }
230 
231 
232 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
233 {
234     if (MEM_isLittleEndian())
235         return MEM_read64(memPtr);
236     else
237     {
238         const BYTE* p = (const BYTE*)memPtr;
239         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
240                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
241     }
242 }
243 
244 
245 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
246 {
247     if (MEM_32bits())
248         return (size_t)MEM_readLE32(memPtr);
249     else
250         return (size_t)MEM_readLE64(memPtr);
251 }
252 
253 #if defined (__cplusplus)
254 }
255 #endif
256 
257 #endif /* MEM_H_MODULE */
258 
259 
260 /* ******************************************************************
261    bitstream
262    Part of NewGen Entropy library
263    header file (to include)
264    Copyright (C) 2013-2015, Yann Collet.
265 
266    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
267 
268    Redistribution and use in source and binary forms, with or without
269    modification, are permitted provided that the following conditions are
270    met:
271 
272        * Redistributions of source code must retain the above copyright
273    notice, this list of conditions and the following disclaimer.
274        * Redistributions in binary form must reproduce the above
275    copyright notice, this list of conditions and the following disclaimer
276    in the documentation and/or other materials provided with the
277    distribution.
278 
279    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
280    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
281    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
282    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
283    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
284    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
285    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
286    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
287    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
288    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
289    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
290 
291    You can contact the author at :
292    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
293    - Public forum : https://groups.google.com/forum/#!forum/lz4c
294 ****************************************************************** */
295 #ifndef BITSTREAM_H_MODULE
296 #define BITSTREAM_H_MODULE
297 
298 #if defined (__cplusplus)
299 extern "C" {
300 #endif
301 
302 
303 /*
304 *  This API consists of small unitary functions, which highly benefit from being inlined.
305 *  Since link-time-optimization is not available for all compilers,
306 *  these functions are defined into a .h to be included.
307 */
308 
309 
310 /**********************************************
311 *  bitStream decompression API (read backward)
312 **********************************************/
313 typedef struct
314 {
315     size_t   bitContainer;
316     unsigned bitsConsumed;
317     const char* ptr;
318     const char* start;
319 } BIT_DStream_t;
320 
321 typedef enum { BIT_DStream_unfinished = 0,
322                BIT_DStream_endOfBuffer = 1,
323                BIT_DStream_completed = 2,
324                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
325                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
326 
327 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
328 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
329 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
330 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
331 
332 
333 /******************************************
334 *  unsafe API
335 ******************************************/
336 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
337 /* faster, but works only if nbBits >= 1 */
338 
339 
340 
341 /****************************************************************
342 *  Helper functions
343 ****************************************************************/
344 MEM_STATIC unsigned BIT_highbit32 (U32 val)
345 {
346 #   if defined(_MSC_VER)   /* Visual */
347     unsigned long r=0;
348     _BitScanReverse ( &r, val );
349     return (unsigned) r;
350 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
351     return 31 - __builtin_clz (val);
352 #   else   /* Software version */
353     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 };
354     U32 v = val;
355     unsigned r;
356     v |= v >> 1;
357     v |= v >> 2;
358     v |= v >> 4;
359     v |= v >> 8;
360     v |= v >> 16;
361     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
362     return r;
363 #   endif
364 }
365 
366 
367 
368 /**********************************************************
369 * bitStream decoding
370 **********************************************************/
371 
372 /*!BIT_initDStream
373 *  Initialize a BIT_DStream_t.
374 *  @bitD : a pointer to an already allocated BIT_DStream_t structure
375 *  @srcBuffer must point at the beginning of a bitStream
376 *  @srcSize must be the exact size of the bitStream
377 *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
378 */
379 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
380 {
381     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
382 
383     if (srcSize >=  sizeof(size_t))   /* normal case */
384     {
385         U32 contain32;
386         bitD->start = (const char*)srcBuffer;
387         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
388         bitD->bitContainer = MEM_readLEST(bitD->ptr);
389         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
390         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
391         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
392     }
393     else
394     {
395         U32 contain32;
396         bitD->start = (const char*)srcBuffer;
397         bitD->ptr   = bitD->start;
398         bitD->bitContainer = *(const BYTE*)(bitD->start);
399         switch(srcSize)
400         {
401             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
402             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
403             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
404             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
405             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
406             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
407             default:;
408         }
409         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
410         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
411         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
412         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
413     }
414 
415     return srcSize;
416 }
417 
418 MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
419 {
420     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
421     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
422 }
423 
424 /*! BIT_lookBitsFast :
425 *   unsafe version; only works only if nbBits >= 1 */
426 MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
427 {
428     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
429     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
430 }
431 
432 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
433 {
434     bitD->bitsConsumed += nbBits;
435 }
436 
437 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
438 {
439     size_t value = BIT_lookBits(bitD, nbBits);
440     BIT_skipBits(bitD, nbBits);
441     return value;
442 }
443 
444 /*!BIT_readBitsFast :
445 *  unsafe version; only works only if nbBits >= 1 */
446 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
447 {
448     size_t value = BIT_lookBitsFast(bitD, nbBits);
449     BIT_skipBits(bitD, nbBits);
450     return value;
451 }
452 
453 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
454 {
455     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
456         return BIT_DStream_overflow;
457 
458     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
459     {
460         bitD->ptr -= bitD->bitsConsumed >> 3;
461         bitD->bitsConsumed &= 7;
462         bitD->bitContainer = MEM_readLEST(bitD->ptr);
463         return BIT_DStream_unfinished;
464     }
465     if (bitD->ptr == bitD->start)
466     {
467         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
468         return BIT_DStream_completed;
469     }
470     {
471         U32 nbBytes = bitD->bitsConsumed >> 3;
472         BIT_DStream_status result = BIT_DStream_unfinished;
473         if (bitD->ptr - nbBytes < bitD->start)
474         {
475             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
476             result = BIT_DStream_endOfBuffer;
477         }
478         bitD->ptr -= nbBytes;
479         bitD->bitsConsumed -= nbBytes*8;
480         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
481         return result;
482     }
483 }
484 
485 /*! BIT_endOfDStream
486 *   @return Tells if DStream has reached its exact end
487 */
488 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
489 {
490     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
491 }
492 
493 #if defined (__cplusplus)
494 }
495 #endif
496 
497 #endif /* BITSTREAM_H_MODULE */
498 /* ******************************************************************
499    Error codes and messages
500    Copyright (C) 2013-2015, Yann Collet
501 
502    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
503 
504    Redistribution and use in source and binary forms, with or without
505    modification, are permitted provided that the following conditions are
506    met:
507 
508        * Redistributions of source code must retain the above copyright
509    notice, this list of conditions and the following disclaimer.
510        * Redistributions in binary form must reproduce the above
511    copyright notice, this list of conditions and the following disclaimer
512    in the documentation and/or other materials provided with the
513    distribution.
514 
515    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
516    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
517    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
518    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
519    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
520    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
521    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
522    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
523    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
524    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
525    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
526 
527    You can contact the author at :
528    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
529    - Public forum : https://groups.google.com/forum/#!forum/lz4c
530 ****************************************************************** */
531 #ifndef ERROR_H_MODULE
532 #define ERROR_H_MODULE
533 
534 #if defined (__cplusplus)
535 extern "C" {
536 #endif
537 
538 
539 /******************************************
540 *  Compiler-specific
541 ******************************************/
542 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
543 #  define ERR_STATIC static inline
544 #elif defined(_MSC_VER)
545 #  define ERR_STATIC static __inline
546 #elif defined(__GNUC__)
547 #  define ERR_STATIC static __attribute__((unused))
548 #else
549 #  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
550 #endif
551 
552 
553 /******************************************
554 *  Error Management
555 ******************************************/
556 #define PREFIX(name) ZSTD_error_##name
557 
558 #define ERROR(name) (size_t)-PREFIX(name)
559 
560 #define ERROR_LIST(ITEM) \
561         ITEM(PREFIX(No_Error)) ITEM(PREFIX(GENERIC)) \
562         ITEM(PREFIX(dstSize_tooSmall)) ITEM(PREFIX(srcSize_wrong)) \
563         ITEM(PREFIX(prefix_unknown)) ITEM(PREFIX(corruption_detected)) \
564         ITEM(PREFIX(tableLog_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooSmall)) \
565         ITEM(PREFIX(maxCode))
566 
567 #define ERROR_GENERATE_ENUM(ENUM) ENUM,
568 typedef enum { ERROR_LIST(ERROR_GENERATE_ENUM) } ERR_codes;  /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
569 
570 #define ERROR_CONVERTTOSTRING(STRING) #STRING,
571 #define ERROR_GENERATE_STRING(EXPR) ERROR_CONVERTTOSTRING(EXPR)
572 static const char* ERR_strings[] = { ERROR_LIST(ERROR_GENERATE_STRING) };
573 
574 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
575 
576 ERR_STATIC const char* ERR_getErrorName(size_t code)
577 {
578     static const char* codeError = "Unspecified error code";
579     if (ERR_isError(code)) return ERR_strings[-(int)(code)];
580     return codeError;
581 }
582 
583 
584 #if defined (__cplusplus)
585 }
586 #endif
587 
588 #endif /* ERROR_H_MODULE */
589 /*
590 Constructor and Destructor of type FSE_CTable
591     Note that its size depends on 'tableLog' and 'maxSymbolValue' */
592 typedef unsigned FSE_CTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
593 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
594 
595 
596 /* ******************************************************************
597    FSE : Finite State Entropy coder
598    header file for static linking (only)
599    Copyright (C) 2013-2015, Yann Collet
600 
601    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
602 
603    Redistribution and use in source and binary forms, with or without
604    modification, are permitted provided that the following conditions are
605    met:
606 
607        * Redistributions of source code must retain the above copyright
608    notice, this list of conditions and the following disclaimer.
609        * Redistributions in binary form must reproduce the above
610    copyright notice, this list of conditions and the following disclaimer
611    in the documentation and/or other materials provided with the
612    distribution.
613 
614    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
615    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
616    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
617    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
618    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
619    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
620    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
621    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
622    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
623    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
624    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
625 
626    You can contact the author at :
627    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
628    - Public forum : https://groups.google.com/forum/#!forum/lz4c
629 ****************************************************************** */
630 #if defined (__cplusplus)
631 extern "C" {
632 #endif
633 
634 
635 /******************************************
636 *  Static allocation
637 ******************************************/
638 /* FSE buffer bounds */
639 #define FSE_NCOUNTBOUND 512
640 #define FSE_BLOCKBOUND(size) (size + (size>>7))
641 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
642 
643 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
644 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
645 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<maxTableLog))
646 
647 
648 /******************************************
649 *  FSE advanced API
650 ******************************************/
651 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
652 /* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
653 
654 static size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
655 /* build a fake FSE_DTable, designed to always generate the same symbolValue */
656 
657 
658 /******************************************
659 *  FSE symbol decompression API
660 ******************************************/
661 typedef struct
662 {
663     size_t      state;
664     const void* table;   /* precise table may vary, depending on U16 */
665 } FSE_DState_t;
666 
667 
668 static void     FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
669 
670 static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
671 
672 static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
673 
674 
675 /******************************************
676 *  FSE unsafe API
677 ******************************************/
678 static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
679 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
680 
681 
682 /******************************************
683 *  Implementation of inline functions
684 ******************************************/
685 
686 /* decompression */
687 
688 typedef struct {
689     U16 tableLog;
690     U16 fastMode;
691 } FSE_DTableHeader;   /* sizeof U32 */
692 
693 typedef struct
694 {
695     unsigned short newState;
696     unsigned char  symbol;
697     unsigned char  nbBits;
698 } FSE_decode_t;   /* size == U32 */
699 
700 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
701 {
702     FSE_DTableHeader DTableH;
703     memcpy(&DTableH, dt, sizeof(DTableH));
704     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
705     BIT_reloadDStream(bitD);
706     DStatePtr->table = dt + 1;
707 }
708 
709 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
710 {
711     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
712     const U32  nbBits = DInfo.nbBits;
713     BYTE symbol = DInfo.symbol;
714     size_t lowBits = BIT_readBits(bitD, nbBits);
715 
716     DStatePtr->state = DInfo.newState + lowBits;
717     return symbol;
718 }
719 
720 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
721 {
722     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
723     const U32 nbBits = DInfo.nbBits;
724     BYTE symbol = DInfo.symbol;
725     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
726 
727     DStatePtr->state = DInfo.newState + lowBits;
728     return symbol;
729 }
730 
731 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
732 {
733     return DStatePtr->state == 0;
734 }
735 
736 
737 #if defined (__cplusplus)
738 }
739 #endif
740 /* ******************************************************************
741    Huff0 : Huffman coder, part of New Generation Entropy library
742    header file for static linking (only)
743    Copyright (C) 2013-2015, Yann Collet
744 
745    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
746 
747    Redistribution and use in source and binary forms, with or without
748    modification, are permitted provided that the following conditions are
749    met:
750 
751        * Redistributions of source code must retain the above copyright
752    notice, this list of conditions and the following disclaimer.
753        * Redistributions in binary form must reproduce the above
754    copyright notice, this list of conditions and the following disclaimer
755    in the documentation and/or other materials provided with the
756    distribution.
757 
758    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
759    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
760    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
761    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
762    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
763    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
764    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
765    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
766    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
767    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
768    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
769 
770    You can contact the author at :
771    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
772    - Public forum : https://groups.google.com/forum/#!forum/lz4c
773 ****************************************************************** */
774 
775 #if defined (__cplusplus)
776 extern "C" {
777 #endif
778 
779 /******************************************
780 *  Static allocation macros
781 ******************************************/
782 /* Huff0 buffer bounds */
783 #define HUF_CTABLEBOUND 129
784 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
785 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
786 
787 /* static allocation of Huff0's DTable */
788 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<maxTableLog))  /* nb Cells; use unsigned short for X2, unsigned int for X4 */
789 #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
790         unsigned short DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
791 #define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
792         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
793 #define HUF_CREATE_STATIC_DTABLEX6(DTable, maxTableLog) \
794         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog) * 3 / 2] = { maxTableLog }
795 
796 
797 /******************************************
798 *  Advanced functions
799 ******************************************/
800 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
801 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbols decoder */
802 static size_t HUF_decompress4X6 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* quad-symbols decoder */
803 
804 
805 #if defined (__cplusplus)
806 }
807 #endif
808 
809 /*
810     zstd - standard compression library
811     Header File
812     Copyright (C) 2014-2015, Yann Collet.
813 
814     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
815 
816     Redistribution and use in source and binary forms, with or without
817     modification, are permitted provided that the following conditions are
818     met:
819     * Redistributions of source code must retain the above copyright
820     notice, this list of conditions and the following disclaimer.
821     * Redistributions in binary form must reproduce the above
822     copyright notice, this list of conditions and the following disclaimer
823     in the documentation and/or other materials provided with the
824     distribution.
825     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
826     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
827     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
828     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
829     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
830     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
831     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
832     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
833     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
834     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
835     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
836 
837     You can contact the author at :
838     - zstd source repository : https://github.com/Cyan4973/zstd
839     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
840 */
841 
842 #if defined (__cplusplus)
843 extern "C" {
844 #endif
845 
846 /* *************************************
847 *  Includes
848 ***************************************/
849 #include <stddef.h>   /* size_t */
850 
851 
852 /* *************************************
853 *  Version
854 ***************************************/
855 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
856 #define ZSTD_VERSION_MINOR    2    /* for new (non-breaking) interface capabilities */
857 #define ZSTD_VERSION_RELEASE  2    /* for tweaks, bug-fixes, or development */
858 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
859 
860 
861 /* *************************************
862 *  Advanced functions
863 ***************************************/
864 typedef struct ZSTD_CCtx_s ZSTD_CCtx;   /* incomplete type */
865 
866 #if defined (__cplusplus)
867 }
868 #endif
869 /*
870     zstd - standard compression library
871     Header File for static linking only
872     Copyright (C) 2014-2015, Yann Collet.
873 
874     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
875 
876     Redistribution and use in source and binary forms, with or without
877     modification, are permitted provided that the following conditions are
878     met:
879     * Redistributions of source code must retain the above copyright
880     notice, this list of conditions and the following disclaimer.
881     * Redistributions in binary form must reproduce the above
882     copyright notice, this list of conditions and the following disclaimer
883     in the documentation and/or other materials provided with the
884     distribution.
885     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
886     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
887     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
888     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
889     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
890     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
891     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
892     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
893     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
894     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
895     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
896 
897     You can contact the author at :
898     - zstd source repository : https://github.com/Cyan4973/zstd
899     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
900 */
901 
902 /* The objects defined into this file should be considered experimental.
903  * They are not labelled stable, as their prototype may change in the future.
904  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
905  */
906 
907 #if defined (__cplusplus)
908 extern "C" {
909 #endif
910 
911 /* *************************************
912 *  Streaming functions
913 ***************************************/
914 
915 typedef struct ZSTD_DCtx_s ZSTD_DCtx;
916 
917 /*
918   Use above functions alternatively.
919   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
920   ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
921   Result is the number of bytes regenerated within 'dst'.
922   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
923 */
924 
925 /* *************************************
926 *  Prefix - version detection
927 ***************************************/
928 #define ZSTD_magicNumber 0xFD2FB522   /* v0.2 (current)*/
929 
930 
931 #if defined (__cplusplus)
932 }
933 #endif
934 /* ******************************************************************
935    FSE : Finite State Entropy coder
936    Copyright (C) 2013-2015, Yann Collet.
937 
938    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
939 
940    Redistribution and use in source and binary forms, with or without
941    modification, are permitted provided that the following conditions are
942    met:
943 
944        * Redistributions of source code must retain the above copyright
945    notice, this list of conditions and the following disclaimer.
946        * Redistributions in binary form must reproduce the above
947    copyright notice, this list of conditions and the following disclaimer
948    in the documentation and/or other materials provided with the
949    distribution.
950 
951    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
952    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
953    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
954    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
955    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
956    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
957    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
958    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
959    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
960    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
961    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
962 
963     You can contact the author at :
964     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
965     - Public forum : https://groups.google.com/forum/#!forum/lz4c
966 ****************************************************************** */
967 
968 #ifndef FSE_COMMONDEFS_ONLY
969 
970 /****************************************************************
971 *  Tuning parameters
972 ****************************************************************/
973 /* MEMORY_USAGE :
974 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
975 *  Increasing memory usage improves compression ratio
976 *  Reduced memory usage can improve speed, due to cache effect
977 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
978 #define FSE_MAX_MEMORY_USAGE 14
979 #define FSE_DEFAULT_MEMORY_USAGE 13
980 
981 /* FSE_MAX_SYMBOL_VALUE :
982 *  Maximum symbol value authorized.
983 *  Required for proper stack allocation */
984 #define FSE_MAX_SYMBOL_VALUE 255
985 
986 
987 /****************************************************************
988 *  template functions type & suffix
989 ****************************************************************/
990 #define FSE_FUNCTION_TYPE BYTE
991 #define FSE_FUNCTION_EXTENSION
992 
993 
994 /****************************************************************
995 *  Byte symbol type
996 ****************************************************************/
997 #endif   /* !FSE_COMMONDEFS_ONLY */
998 
999 
1000 /****************************************************************
1001 *  Compiler specifics
1002 ****************************************************************/
1003 #ifdef _MSC_VER    /* Visual Studio */
1004 #  define FORCE_INLINE static __forceinline
1005 #  include <intrin.h>                    /* For Visual 2005 */
1006 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1007 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
1008 #else
1009 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
1010 #    ifdef __GNUC__
1011 #      define FORCE_INLINE static inline __attribute__((always_inline))
1012 #    else
1013 #      define FORCE_INLINE static inline
1014 #    endif
1015 #  else
1016 #    define FORCE_INLINE static
1017 #  endif /* __STDC_VERSION__ */
1018 #endif
1019 
1020 
1021 /****************************************************************
1022 *  Includes
1023 ****************************************************************/
1024 #include <stdlib.h>     /* malloc, free, qsort */
1025 #include <string.h>     /* memcpy, memset */
1026 #include <stdio.h>      /* printf (debug) */
1027 
1028 /****************************************************************
1029 *  Constants
1030 *****************************************************************/
1031 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
1032 #define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
1033 #define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
1034 #define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
1035 #define FSE_MIN_TABLELOG 5
1036 
1037 #define FSE_TABLELOG_ABSOLUTE_MAX 15
1038 #if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
1039 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
1040 #endif
1041 
1042 
1043 /****************************************************************
1044 *  Error Management
1045 ****************************************************************/
1046 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1047 
1048 
1049 /****************************************************************
1050 *  Complex types
1051 ****************************************************************/
1052 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
1053 
1054 
1055 /****************************************************************
1056 *  Templates
1057 ****************************************************************/
1058 /*
1059   designed to be included
1060   for type-specific functions (template emulation in C)
1061   Objective is to write these functions only once, for improved maintenance
1062 */
1063 
1064 /* safety checks */
1065 #ifndef FSE_FUNCTION_EXTENSION
1066 #  error "FSE_FUNCTION_EXTENSION must be defined"
1067 #endif
1068 #ifndef FSE_FUNCTION_TYPE
1069 #  error "FSE_FUNCTION_TYPE must be defined"
1070 #endif
1071 
1072 /* Function names */
1073 #define FSE_CAT(X,Y) X##Y
1074 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
1075 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
1076 
1077 
1078 /* Function templates */
1079 
1080 #define FSE_DECODE_TYPE FSE_decode_t
1081 
1082 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
1083 
1084 static size_t FSE_buildDTable
1085 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
1086 {
1087     void* ptr = dt+1;
1088     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)ptr;
1089     FSE_DTableHeader DTableH;
1090     const U32 tableSize = 1 << tableLog;
1091     const U32 tableMask = tableSize-1;
1092     const U32 step = FSE_tableStep(tableSize);
1093     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
1094     U32 position = 0;
1095     U32 highThreshold = tableSize-1;
1096     const S16 largeLimit= (S16)(1 << (tableLog-1));
1097     U32 noLarge = 1;
1098     U32 s;
1099 
1100     /* Sanity Checks */
1101     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
1102     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
1103 
1104     /* Init, lay down lowprob symbols */
1105     DTableH.tableLog = (U16)tableLog;
1106     for (s=0; s<=maxSymbolValue; s++)
1107     {
1108         if (normalizedCounter[s]==-1)
1109         {
1110             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
1111             symbolNext[s] = 1;
1112         }
1113         else
1114         {
1115             if (normalizedCounter[s] >= largeLimit) noLarge=0;
1116             symbolNext[s] = normalizedCounter[s];
1117         }
1118     }
1119 
1120     /* Spread symbols */
1121     for (s=0; s<=maxSymbolValue; s++)
1122     {
1123         int i;
1124         for (i=0; i<normalizedCounter[s]; i++)
1125         {
1126             tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
1127             position = (position + step) & tableMask;
1128             while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
1129         }
1130     }
1131 
1132     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
1133 
1134     /* Build Decoding table */
1135     {
1136         U32 i;
1137         for (i=0; i<tableSize; i++)
1138         {
1139             FSE_FUNCTION_TYPE symbol = (FSE_FUNCTION_TYPE)(tableDecode[i].symbol);
1140             U16 nextState = symbolNext[symbol]++;
1141             tableDecode[i].nbBits = (BYTE) (tableLog - BIT_highbit32 ((U32)nextState) );
1142             tableDecode[i].newState = (U16) ( (nextState << tableDecode[i].nbBits) - tableSize);
1143         }
1144     }
1145 
1146     DTableH.fastMode = (U16)noLarge;
1147     memcpy(dt, &DTableH, sizeof(DTableH));   /* memcpy(), to avoid strict aliasing warnings */
1148     return 0;
1149 }
1150 
1151 
1152 #ifndef FSE_COMMONDEFS_ONLY
1153 /******************************************
1154 *  FSE helper functions
1155 ******************************************/
1156 static unsigned FSE_isError(size_t code) { return ERR_isError(code); }
1157 
1158 
1159 /****************************************************************
1160 *  FSE NCount encoding-decoding
1161 ****************************************************************/
1162 static short FSE_abs(short a)
1163 {
1164     return (short)(a<0 ? -a : a);
1165 }
1166 
1167 static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
1168                  const void* headerBuffer, size_t hbSize)
1169 {
1170     const BYTE* const istart = (const BYTE*) headerBuffer;
1171     const BYTE* const iend = istart + hbSize;
1172     const BYTE* ip = istart;
1173     int nbBits;
1174     int remaining;
1175     int threshold;
1176     U32 bitStream;
1177     int bitCount;
1178     unsigned charnum = 0;
1179     int previous0 = 0;
1180 
1181     if (hbSize < 4) return ERROR(srcSize_wrong);
1182     bitStream = MEM_readLE32(ip);
1183     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
1184     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
1185     bitStream >>= 4;
1186     bitCount = 4;
1187     *tableLogPtr = nbBits;
1188     remaining = (1<<nbBits)+1;
1189     threshold = 1<<nbBits;
1190     nbBits++;
1191 
1192     while ((remaining>1) && (charnum<=*maxSVPtr))
1193     {
1194         if (previous0)
1195         {
1196             unsigned n0 = charnum;
1197             while ((bitStream & 0xFFFF) == 0xFFFF)
1198             {
1199                 n0+=24;
1200                 if (ip < iend-5)
1201                 {
1202                     ip+=2;
1203                     bitStream = MEM_readLE32(ip) >> bitCount;
1204                 }
1205                 else
1206                 {
1207                     bitStream >>= 16;
1208                     bitCount+=16;
1209                 }
1210             }
1211             while ((bitStream & 3) == 3)
1212             {
1213                 n0+=3;
1214                 bitStream>>=2;
1215                 bitCount+=2;
1216             }
1217             n0 += bitStream & 3;
1218             bitCount += 2;
1219             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
1220             while (charnum < n0) normalizedCounter[charnum++] = 0;
1221             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1222             {
1223                 ip += bitCount>>3;
1224                 bitCount &= 7;
1225                 bitStream = MEM_readLE32(ip) >> bitCount;
1226             }
1227             else
1228                 bitStream >>= 2;
1229         }
1230         {
1231             const short max = (short)((2*threshold-1)-remaining);
1232             short count;
1233 
1234             if ((bitStream & (threshold-1)) < (U32)max)
1235             {
1236                 count = (short)(bitStream & (threshold-1));
1237                 bitCount   += nbBits-1;
1238             }
1239             else
1240             {
1241                 count = (short)(bitStream & (2*threshold-1));
1242                 if (count >= threshold) count -= max;
1243                 bitCount   += nbBits;
1244             }
1245 
1246             count--;   /* extra accuracy */
1247             remaining -= FSE_abs(count);
1248             normalizedCounter[charnum++] = count;
1249             previous0 = !count;
1250             while (remaining < threshold)
1251             {
1252                 nbBits--;
1253                 threshold >>= 1;
1254             }
1255 
1256             {
1257                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1258                 {
1259                     ip += bitCount>>3;
1260                     bitCount &= 7;
1261                 }
1262                 else
1263                 {
1264                     bitCount -= (int)(8 * (iend - 4 - ip));
1265                     ip = iend - 4;
1266                 }
1267                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
1268             }
1269         }
1270     }
1271     if (remaining != 1) return ERROR(GENERIC);
1272     *maxSVPtr = charnum-1;
1273 
1274     ip += (bitCount+7)>>3;
1275     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
1276     return ip-istart;
1277 }
1278 
1279 
1280 /*********************************************************
1281 *  Decompression (Byte symbols)
1282 *********************************************************/
1283 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
1284 {
1285     void* ptr = dt;
1286     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1287     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
1288 
1289     DTableH->tableLog = 0;
1290     DTableH->fastMode = 0;
1291 
1292     cell->newState = 0;
1293     cell->symbol = symbolValue;
1294     cell->nbBits = 0;
1295 
1296     return 0;
1297 }
1298 
1299 
1300 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
1301 {
1302     void* ptr = dt;
1303     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1304     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
1305     const unsigned tableSize = 1 << nbBits;
1306     const unsigned tableMask = tableSize - 1;
1307     const unsigned maxSymbolValue = tableMask;
1308     unsigned s;
1309 
1310     /* Sanity checks */
1311     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
1312 
1313     /* Build Decoding Table */
1314     DTableH->tableLog = (U16)nbBits;
1315     DTableH->fastMode = 1;
1316     for (s=0; s<=maxSymbolValue; s++)
1317     {
1318         dinfo[s].newState = 0;
1319         dinfo[s].symbol = (BYTE)s;
1320         dinfo[s].nbBits = (BYTE)nbBits;
1321     }
1322 
1323     return 0;
1324 }
1325 
1326 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
1327           void* dst, size_t maxDstSize,
1328     const void* cSrc, size_t cSrcSize,
1329     const FSE_DTable* dt, const unsigned fast)
1330 {
1331     BYTE* const ostart = (BYTE*) dst;
1332     BYTE* op = ostart;
1333     BYTE* const omax = op + maxDstSize;
1334     BYTE* const olimit = omax-3;
1335 
1336     BIT_DStream_t bitD;
1337     FSE_DState_t state1;
1338     FSE_DState_t state2;
1339     size_t errorCode;
1340 
1341     /* Init */
1342     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
1343     if (FSE_isError(errorCode)) return errorCode;
1344 
1345     FSE_initDState(&state1, &bitD, dt);
1346     FSE_initDState(&state2, &bitD, dt);
1347 
1348 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
1349 
1350     /* 4 symbols per loop */
1351     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op<olimit) ; op+=4)
1352     {
1353         op[0] = FSE_GETSYMBOL(&state1);
1354 
1355         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1356             BIT_reloadDStream(&bitD);
1357 
1358         op[1] = FSE_GETSYMBOL(&state2);
1359 
1360         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1361             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
1362 
1363         op[2] = FSE_GETSYMBOL(&state1);
1364 
1365         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1366             BIT_reloadDStream(&bitD);
1367 
1368         op[3] = FSE_GETSYMBOL(&state2);
1369     }
1370 
1371     /* tail */
1372     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
1373     while (1)
1374     {
1375         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
1376             break;
1377 
1378         *op++ = FSE_GETSYMBOL(&state1);
1379 
1380         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
1381             break;
1382 
1383         *op++ = FSE_GETSYMBOL(&state2);
1384     }
1385 
1386     /* end ? */
1387     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
1388         return op-ostart;
1389 
1390     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
1391 
1392     return ERROR(corruption_detected);
1393 }
1394 
1395 
1396 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
1397                             const void* cSrc, size_t cSrcSize,
1398                             const FSE_DTable* dt)
1399 {
1400     FSE_DTableHeader DTableH;
1401     memcpy(&DTableH, dt, sizeof(DTableH));
1402 
1403     /* select fast mode (static) */
1404     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
1405     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
1406 }
1407 
1408 
1409 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
1410 {
1411     const BYTE* const istart = (const BYTE*)cSrc;
1412     const BYTE* ip = istart;
1413     short counting[FSE_MAX_SYMBOL_VALUE+1];
1414     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
1415     unsigned tableLog;
1416     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
1417     size_t errorCode;
1418 
1419     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
1420 
1421     /* normal FSE decoding mode */
1422     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
1423     if (FSE_isError(errorCode)) return errorCode;
1424     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
1425     ip += errorCode;
1426     cSrcSize -= errorCode;
1427 
1428     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
1429     if (FSE_isError(errorCode)) return errorCode;
1430 
1431     /* always return, even if it is an error code */
1432     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
1433 }
1434 
1435 
1436 
1437 #endif   /* FSE_COMMONDEFS_ONLY */
1438 /* ******************************************************************
1439    Huff0 : Huffman coder, part of New Generation Entropy library
1440    Copyright (C) 2013-2015, Yann Collet.
1441 
1442    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1443 
1444    Redistribution and use in source and binary forms, with or without
1445    modification, are permitted provided that the following conditions are
1446    met:
1447 
1448        * Redistributions of source code must retain the above copyright
1449    notice, this list of conditions and the following disclaimer.
1450        * Redistributions in binary form must reproduce the above
1451    copyright notice, this list of conditions and the following disclaimer
1452    in the documentation and/or other materials provided with the
1453    distribution.
1454 
1455    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1456    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1457    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1458    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1459    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1460    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1461    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1462    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1463    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1464    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1465    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1466 
1467     You can contact the author at :
1468     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
1469     - Public forum : https://groups.google.com/forum/#!forum/lz4c
1470 ****************************************************************** */
1471 
1472 /****************************************************************
1473 *  Compiler specifics
1474 ****************************************************************/
1475 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
1476 /* inline is defined */
1477 #elif defined(_MSC_VER)
1478 #  define inline __inline
1479 #else
1480 #  define inline /* disable inline */
1481 #endif
1482 
1483 
1484 #ifdef _MSC_VER    /* Visual Studio */
1485 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1486 #endif
1487 
1488 
1489 /****************************************************************
1490 *  Includes
1491 ****************************************************************/
1492 #include <stdlib.h>     /* malloc, free, qsort */
1493 #include <string.h>     /* memcpy, memset */
1494 #include <stdio.h>      /* printf (debug) */
1495 
1496 /****************************************************************
1497 *  Error Management
1498 ****************************************************************/
1499 #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1500 
1501 
1502 /******************************************
1503 *  Helper functions
1504 ******************************************/
1505 static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
1506 
1507 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
1508 #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
1509 #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
1510 #define HUF_MAX_SYMBOL_VALUE 255
1511 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
1512 #  error "HUF_MAX_TABLELOG is too large !"
1513 #endif
1514 
1515 
1516 
1517 /*********************************************************
1518 *  Huff0 : Huffman block decompression
1519 *********************************************************/
1520 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
1521 
1522 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
1523 
1524 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
1525 
1526 /*! HUF_readStats
1527     Read compact Huffman tree, saved by HUF_writeCTable
1528     @huffWeight : destination buffer
1529     @return : size read from `src`
1530 */
1531 static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
1532                             U32* nbSymbolsPtr, U32* tableLogPtr,
1533                             const void* src, size_t srcSize)
1534 {
1535     U32 weightTotal;
1536     U32 tableLog;
1537     const BYTE* ip = (const BYTE*) src;
1538     size_t iSize;
1539     size_t oSize;
1540     U32 n;
1541 
1542     if (!srcSize) return ERROR(srcSize_wrong);
1543     iSize = ip[0];
1544     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
1545 
1546     if (iSize >= 128)  /* special header */
1547     {
1548         if (iSize >= (242))   /* RLE */
1549         {
1550             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
1551             oSize = l[iSize-242];
1552             memset(huffWeight, 1, hwSize);
1553             iSize = 0;
1554         }
1555         else   /* Incompressible */
1556         {
1557             oSize = iSize - 127;
1558             iSize = ((oSize+1)/2);
1559             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1560             if (oSize >= hwSize) return ERROR(corruption_detected);
1561             ip += 1;
1562             for (n=0; n<oSize; n+=2)
1563             {
1564                 huffWeight[n]   = ip[n/2] >> 4;
1565                 huffWeight[n+1] = ip[n/2] & 15;
1566             }
1567         }
1568     }
1569     else  /* header compressed with FSE (normal case) */
1570     {
1571         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1572         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
1573         if (FSE_isError(oSize)) return oSize;
1574     }
1575 
1576     /* collect weight stats */
1577     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
1578     weightTotal = 0;
1579     for (n=0; n<oSize; n++)
1580     {
1581         if (huffWeight[n] >= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1582         rankStats[huffWeight[n]]++;
1583         weightTotal += (1 << huffWeight[n]) >> 1;
1584     }
1585     if (weightTotal == 0) return ERROR(corruption_detected);
1586 
1587     /* get last non-null symbol weight (implied, total must be 2^n) */
1588     tableLog = BIT_highbit32(weightTotal) + 1;
1589     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1590     {
1591         U32 total = 1 << tableLog;
1592         U32 rest = total - weightTotal;
1593         U32 verif = 1 << BIT_highbit32(rest);
1594         U32 lastWeight = BIT_highbit32(rest) + 1;
1595         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
1596         huffWeight[oSize] = (BYTE)lastWeight;
1597         rankStats[lastWeight]++;
1598     }
1599 
1600     /* check tree construction validity */
1601     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
1602 
1603     /* results */
1604     *nbSymbolsPtr = (U32)(oSize+1);
1605     *tableLogPtr = tableLog;
1606     return iSize+1;
1607 }
1608 
1609 
1610 /**************************/
1611 /* single-symbol decoding */
1612 /**************************/
1613 
1614 static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
1615 {
1616     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
1617     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
1618     U32 tableLog = 0;
1619     const BYTE* ip = (const BYTE*) src;
1620     size_t iSize = ip[0];
1621     U32 nbSymbols = 0;
1622     U32 n;
1623     U32 nextRankStart;
1624     void* ptr = DTable+1;
1625     HUF_DEltX2* const dt = (HUF_DEltX2*)ptr;
1626 
1627     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
1628     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
1629 
1630     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
1631     if (HUF_isError(iSize)) return iSize;
1632 
1633     /* check result */
1634     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
1635     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
1636 
1637     /* Prepare ranks */
1638     nextRankStart = 0;
1639     for (n=1; n<=tableLog; n++)
1640     {
1641         U32 current = nextRankStart;
1642         nextRankStart += (rankVal[n] << (n-1));
1643         rankVal[n] = current;
1644     }
1645 
1646     /* fill DTable */
1647     for (n=0; n<nbSymbols; n++)
1648     {
1649         const U32 w = huffWeight[n];
1650         const U32 length = (1 << w) >> 1;
1651         U32 i;
1652         HUF_DEltX2 D;
1653         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
1654         for (i = rankVal[w]; i < rankVal[w] + length; i++)
1655             dt[i] = D;
1656         rankVal[w] += length;
1657     }
1658 
1659     return iSize;
1660 }
1661 
1662 static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
1663 {
1664         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
1665         const BYTE c = dt[val].byte;
1666         BIT_skipBits(Dstream, dt[val].nbBits);
1667         return c;
1668 }
1669 
1670 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
1671     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
1672 
1673 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
1674     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
1675         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1676 
1677 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
1678     if (MEM_64bits()) \
1679         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1680 
1681 static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
1682 {
1683     BYTE* const pStart = p;
1684 
1685     /* up to 4 symbols at a time */
1686     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
1687     {
1688         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1689         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
1690         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1691         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1692     }
1693 
1694     /* closer to the end */
1695     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
1696         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1697 
1698     /* no more data to retrieve from bitstream, hence no need to reload */
1699     while (p < pEnd)
1700         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1701 
1702     return pEnd-pStart;
1703 }
1704 
1705 
1706 static size_t HUF_decompress4X2_usingDTable(
1707           void* dst,  size_t dstSize,
1708     const void* cSrc, size_t cSrcSize,
1709     const U16* DTable)
1710 {
1711     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
1712 
1713     {
1714         const BYTE* const istart = (const BYTE*) cSrc;
1715         BYTE* const ostart = (BYTE*) dst;
1716         BYTE* const oend = ostart + dstSize;
1717 
1718         const void* ptr = DTable;
1719         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)ptr) +1;
1720         const U32 dtLog = DTable[0];
1721         size_t errorCode;
1722 
1723         /* Init */
1724         BIT_DStream_t bitD1;
1725         BIT_DStream_t bitD2;
1726         BIT_DStream_t bitD3;
1727         BIT_DStream_t bitD4;
1728         const size_t length1 = MEM_readLE16(istart);
1729         const size_t length2 = MEM_readLE16(istart+2);
1730         const size_t length3 = MEM_readLE16(istart+4);
1731         size_t length4;
1732         const BYTE* const istart1 = istart + 6;  /* jumpTable */
1733         const BYTE* const istart2 = istart1 + length1;
1734         const BYTE* const istart3 = istart2 + length2;
1735         const BYTE* const istart4 = istart3 + length3;
1736         const size_t segmentSize = (dstSize+3) / 4;
1737         BYTE* const opStart2 = ostart + segmentSize;
1738         BYTE* const opStart3 = opStart2 + segmentSize;
1739         BYTE* const opStart4 = opStart3 + segmentSize;
1740         BYTE* op1 = ostart;
1741         BYTE* op2 = opStart2;
1742         BYTE* op3 = opStart3;
1743         BYTE* op4 = opStart4;
1744         U32 endSignal;
1745 
1746         length4 = cSrcSize - (length1 + length2 + length3 + 6);
1747         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
1748         errorCode = BIT_initDStream(&bitD1, istart1, length1);
1749         if (HUF_isError(errorCode)) return errorCode;
1750         errorCode = BIT_initDStream(&bitD2, istart2, length2);
1751         if (HUF_isError(errorCode)) return errorCode;
1752         errorCode = BIT_initDStream(&bitD3, istart3, length3);
1753         if (HUF_isError(errorCode)) return errorCode;
1754         errorCode = BIT_initDStream(&bitD4, istart4, length4);
1755         if (HUF_isError(errorCode)) return errorCode;
1756 
1757         /* 16-32 symbols per loop (4-8 symbols per stream) */
1758         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1759         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
1760         {
1761             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1762             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1763             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1764             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1765             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
1766             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
1767             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
1768             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
1769             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1770             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1771             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1772             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1773             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
1774             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
1775             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
1776             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
1777 
1778             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1779         }
1780 
1781         /* check corruption */
1782         if (op1 > opStart2) return ERROR(corruption_detected);
1783         if (op2 > opStart3) return ERROR(corruption_detected);
1784         if (op3 > opStart4) return ERROR(corruption_detected);
1785         /* note : op4 supposed already verified within main loop */
1786 
1787         /* finish bitStreams one by one */
1788         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
1789         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
1790         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
1791         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
1792 
1793         /* check */
1794         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
1795         if (!endSignal) return ERROR(corruption_detected);
1796 
1797         /* decoded size */
1798         return dstSize;
1799     }
1800 }
1801 
1802 
1803 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
1804 {
1805     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
1806     const BYTE* ip = (const BYTE*) cSrc;
1807     size_t errorCode;
1808 
1809     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
1810     if (HUF_isError(errorCode)) return errorCode;
1811     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
1812     ip += errorCode;
1813     cSrcSize -= errorCode;
1814 
1815     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
1816 }
1817 
1818 
1819 /***************************/
1820 /* double-symbols decoding */
1821 /***************************/
1822 
1823 static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
1824                            const U32* rankValOrigin, const int minWeight,
1825                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
1826                            U32 nbBitsBaseline, U16 baseSeq)
1827 {
1828     HUF_DEltX4 DElt;
1829     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1830     U32 s;
1831 
1832     /* get pre-calculated rankVal */
1833     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1834 
1835     /* fill skipped values */
1836     if (minWeight>1)
1837     {
1838         U32 i, skipSize = rankVal[minWeight];
1839         MEM_writeLE16(&(DElt.sequence), baseSeq);
1840         DElt.nbBits   = (BYTE)(consumed);
1841         DElt.length   = 1;
1842         for (i = 0; i < skipSize; i++)
1843             DTable[i] = DElt;
1844     }
1845 
1846     /* fill DTable */
1847     for (s=0; s<sortedListSize; s++)   /* note : sortedSymbols already skipped */
1848     {
1849         const U32 symbol = sortedSymbols[s].symbol;
1850         const U32 weight = sortedSymbols[s].weight;
1851         const U32 nbBits = nbBitsBaseline - weight;
1852         const U32 length = 1 << (sizeLog-nbBits);
1853         const U32 start = rankVal[weight];
1854         U32 i = start;
1855         const U32 end = start + length;
1856 
1857         MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
1858         DElt.nbBits = (BYTE)(nbBits + consumed);
1859         DElt.length = 2;
1860         do { DTable[i++] = DElt; } while (i<end);   /* since length >= 1 */
1861 
1862         rankVal[weight] += length;
1863     }
1864 }
1865 
1866 typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
1867 
1868 static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
1869                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
1870                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
1871                            const U32 nbBitsBaseline)
1872 {
1873     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1874     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
1875     const U32 minBits  = nbBitsBaseline - maxWeight;
1876     U32 s;
1877 
1878     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1879 
1880     /* fill DTable */
1881     for (s=0; s<sortedListSize; s++)
1882     {
1883         const U16 symbol = sortedList[s].symbol;
1884         const U32 weight = sortedList[s].weight;
1885         const U32 nbBits = nbBitsBaseline - weight;
1886         const U32 start = rankVal[weight];
1887         const U32 length = 1 << (targetLog-nbBits);
1888 
1889         if (targetLog-nbBits >= minBits)   /* enough room for a second symbol */
1890         {
1891             U32 sortedRank;
1892             int minWeight = nbBits + scaleLog;
1893             if (minWeight < 1) minWeight = 1;
1894             sortedRank = rankStart[minWeight];
1895             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
1896                            rankValOrigin[nbBits], minWeight,
1897                            sortedList+sortedRank, sortedListSize-sortedRank,
1898                            nbBitsBaseline, symbol);
1899         }
1900         else
1901         {
1902             U32 i;
1903             const U32 end = start + length;
1904             HUF_DEltX4 DElt;
1905 
1906             MEM_writeLE16(&(DElt.sequence), symbol);
1907             DElt.nbBits   = (BYTE)(nbBits);
1908             DElt.length   = 1;
1909             for (i = start; i < end; i++)
1910                 DTable[i] = DElt;
1911         }
1912         rankVal[weight] += length;
1913     }
1914 }
1915 
1916 static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
1917 {
1918     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
1919     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
1920     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
1921     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
1922     U32* const rankStart = rankStart0+1;
1923     rankVal_t rankVal;
1924     U32 tableLog, maxW, sizeOfSort, nbSymbols;
1925     const U32 memLog = DTable[0];
1926     const BYTE* ip = (const BYTE*) src;
1927     size_t iSize = ip[0];
1928     void* ptr = DTable;
1929     HUF_DEltX4* const dt = ((HUF_DEltX4*)ptr) + 1;
1930 
1931     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
1932     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
1933     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
1934 
1935     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
1936     if (HUF_isError(iSize)) return iSize;
1937 
1938     /* check result */
1939     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
1940 
1941     /* find maxWeight */
1942     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
1943         {if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
1944 
1945     /* Get start index of each weight */
1946     {
1947         U32 w, nextRankStart = 0;
1948         for (w=1; w<=maxW; w++)
1949         {
1950             U32 current = nextRankStart;
1951             nextRankStart += rankStats[w];
1952             rankStart[w] = current;
1953         }
1954         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
1955         sizeOfSort = nextRankStart;
1956     }
1957 
1958     /* sort symbols by weight */
1959     {
1960         U32 s;
1961         for (s=0; s<nbSymbols; s++)
1962         {
1963             U32 w = weightList[s];
1964             U32 r = rankStart[w]++;
1965             sortedSymbol[r].symbol = (BYTE)s;
1966             sortedSymbol[r].weight = (BYTE)w;
1967         }
1968         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
1969     }
1970 
1971     /* Build rankVal */
1972     {
1973         const U32 minBits = tableLog+1 - maxW;
1974         U32 nextRankVal = 0;
1975         U32 w, consumed;
1976         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
1977         U32* rankVal0 = rankVal[0];
1978         for (w=1; w<=maxW; w++)
1979         {
1980             U32 current = nextRankVal;
1981             nextRankVal += rankStats[w] << (w+rescale);
1982             rankVal0[w] = current;
1983         }
1984         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
1985         {
1986             U32* rankValPtr = rankVal[consumed];
1987             for (w = 1; w <= maxW; w++)
1988             {
1989                 rankValPtr[w] = rankVal0[w] >> consumed;
1990             }
1991         }
1992     }
1993 
1994     HUF_fillDTableX4(dt, memLog,
1995                    sortedSymbol, sizeOfSort,
1996                    rankStart0, rankVal, maxW,
1997                    tableLog+1);
1998 
1999     return iSize;
2000 }
2001 
2002 
2003 static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2004 {
2005     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2006     memcpy(op, dt+val, 2);
2007     BIT_skipBits(DStream, dt[val].nbBits);
2008     return dt[val].length;
2009 }
2010 
2011 static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2012 {
2013     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2014     memcpy(op, dt+val, 1);
2015     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
2016     else
2017     {
2018         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
2019         {
2020             BIT_skipBits(DStream, dt[val].nbBits);
2021             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2022                 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 */
2023         }
2024     }
2025     return 1;
2026 }
2027 
2028 
2029 #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
2030     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2031 
2032 #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
2033     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
2034         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2035 
2036 #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
2037     if (MEM_64bits()) \
2038         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2039 
2040 static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
2041 {
2042     BYTE* const pStart = p;
2043 
2044     /* up to 8 symbols at a time */
2045     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
2046     {
2047         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2048         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
2049         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2050         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2051     }
2052 
2053     /* closer to the end */
2054     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
2055         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2056 
2057     while (p <= pEnd-2)
2058         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2059 
2060     if (p < pEnd)
2061         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
2062 
2063     return p-pStart;
2064 }
2065 
2066 
2067 
2068 static size_t HUF_decompress4X4_usingDTable(
2069           void* dst,  size_t dstSize,
2070     const void* cSrc, size_t cSrcSize,
2071     const U32* DTable)
2072 {
2073     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2074 
2075     {
2076         const BYTE* const istart = (const BYTE*) cSrc;
2077         BYTE* const ostart = (BYTE*) dst;
2078         BYTE* const oend = ostart + dstSize;
2079 
2080         const void* ptr = DTable;
2081         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)ptr) +1;
2082         const U32 dtLog = DTable[0];
2083         size_t errorCode;
2084 
2085         /* Init */
2086         BIT_DStream_t bitD1;
2087         BIT_DStream_t bitD2;
2088         BIT_DStream_t bitD3;
2089         BIT_DStream_t bitD4;
2090         const size_t length1 = MEM_readLE16(istart);
2091         const size_t length2 = MEM_readLE16(istart+2);
2092         const size_t length3 = MEM_readLE16(istart+4);
2093         size_t length4;
2094         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2095         const BYTE* const istart2 = istart1 + length1;
2096         const BYTE* const istart3 = istart2 + length2;
2097         const BYTE* const istart4 = istart3 + length3;
2098         const size_t segmentSize = (dstSize+3) / 4;
2099         BYTE* const opStart2 = ostart + segmentSize;
2100         BYTE* const opStart3 = opStart2 + segmentSize;
2101         BYTE* const opStart4 = opStart3 + segmentSize;
2102         BYTE* op1 = ostart;
2103         BYTE* op2 = opStart2;
2104         BYTE* op3 = opStart3;
2105         BYTE* op4 = opStart4;
2106         U32 endSignal;
2107 
2108         length4 = cSrcSize - (length1 + length2 + length3 + 6);
2109         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2110         errorCode = BIT_initDStream(&bitD1, istart1, length1);
2111         if (HUF_isError(errorCode)) return errorCode;
2112         errorCode = BIT_initDStream(&bitD2, istart2, length2);
2113         if (HUF_isError(errorCode)) return errorCode;
2114         errorCode = BIT_initDStream(&bitD3, istart3, length3);
2115         if (HUF_isError(errorCode)) return errorCode;
2116         errorCode = BIT_initDStream(&bitD4, istart4, length4);
2117         if (HUF_isError(errorCode)) return errorCode;
2118 
2119         /* 16-32 symbols per loop (4-8 symbols per stream) */
2120         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2121         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
2122         {
2123             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2124             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2125             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2126             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2127             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
2128             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
2129             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
2130             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
2131             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2132             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2133             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2134             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2135             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
2136             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
2137             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
2138             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
2139 
2140             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2141         }
2142 
2143         /* check corruption */
2144         if (op1 > opStart2) return ERROR(corruption_detected);
2145         if (op2 > opStart3) return ERROR(corruption_detected);
2146         if (op3 > opStart4) return ERROR(corruption_detected);
2147         /* note : op4 supposed already verified within main loop */
2148 
2149         /* finish bitStreams one by one */
2150         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
2151         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
2152         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
2153         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
2154 
2155         /* check */
2156         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
2157         if (!endSignal) return ERROR(corruption_detected);
2158 
2159         /* decoded size */
2160         return dstSize;
2161     }
2162 }
2163 
2164 
2165 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2166 {
2167     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
2168     const BYTE* ip = (const BYTE*) cSrc;
2169 
2170     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
2171     if (HUF_isError(hSize)) return hSize;
2172     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2173     ip += hSize;
2174     cSrcSize -= hSize;
2175 
2176     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
2177 }
2178 
2179 
2180 /**********************************/
2181 /* quad-symbol decoding           */
2182 /**********************************/
2183 typedef struct { BYTE nbBits; BYTE nbBytes; } HUF_DDescX6;
2184 typedef union { BYTE byte[4]; U32 sequence; } HUF_DSeqX6;
2185 
2186 /* recursive, up to level 3; may benefit from <template>-like strategy to nest each level inline */
2187 static void HUF_fillDTableX6LevelN(HUF_DDescX6* DDescription, HUF_DSeqX6* DSequence, int sizeLog,
2188                            const rankVal_t rankValOrigin, const U32 consumed, const int minWeight, const U32 maxWeight,
2189                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize, const U32* rankStart,
2190                            const U32 nbBitsBaseline, HUF_DSeqX6 baseSeq, HUF_DDescX6 DDesc)
2191 {
2192     const int scaleLog = nbBitsBaseline - sizeLog;   /* note : targetLog >= (nbBitsBaseline-1), hence scaleLog <= 1 */
2193     const int minBits  = nbBitsBaseline - maxWeight;
2194     const U32 level = DDesc.nbBytes;
2195     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
2196     U32 symbolStartPos, s;
2197 
2198     /* local rankVal, will be modified */
2199     memcpy(rankVal, rankValOrigin[consumed], sizeof(rankVal));
2200 
2201     /* fill skipped values */
2202     if (minWeight>1)
2203     {
2204         U32 i;
2205         const U32 skipSize = rankVal[minWeight];
2206         for (i = 0; i < skipSize; i++)
2207         {
2208             DSequence[i] = baseSeq;
2209             DDescription[i] = DDesc;
2210         }
2211     }
2212 
2213     /* fill DTable */
2214     DDesc.nbBytes++;
2215     symbolStartPos = rankStart[minWeight];
2216     for (s=symbolStartPos; s<sortedListSize; s++)
2217     {
2218         const BYTE symbol = sortedSymbols[s].symbol;
2219         const U32  weight = sortedSymbols[s].weight;   /* >= 1 (sorted) */
2220         const int  nbBits = nbBitsBaseline - weight;   /* >= 1 (by construction) */
2221         const int  totalBits = consumed+nbBits;
2222         const U32  start  = rankVal[weight];
2223         const U32  length = 1 << (sizeLog-nbBits);
2224         baseSeq.byte[level] = symbol;
2225         DDesc.nbBits = (BYTE)totalBits;
2226 
2227         if ((level<3) && (sizeLog-totalBits >= minBits))   /* enough room for another symbol */
2228         {
2229             int nextMinWeight = totalBits + scaleLog;
2230             if (nextMinWeight < 1) nextMinWeight = 1;
2231             HUF_fillDTableX6LevelN(DDescription+start, DSequence+start, sizeLog-nbBits,
2232                            rankValOrigin, totalBits, nextMinWeight, maxWeight,
2233                            sortedSymbols, sortedListSize, rankStart,
2234                            nbBitsBaseline, baseSeq, DDesc);   /* recursive (max : level 3) */
2235         }
2236         else
2237         {
2238             U32 i;
2239             const U32 end = start + length;
2240             for (i = start; i < end; i++)
2241             {
2242                 DDescription[i] = DDesc;
2243                 DSequence[i] = baseSeq;
2244             }
2245         }
2246         rankVal[weight] += length;
2247     }
2248 }
2249 
2250 
2251 /* note : same preparation as X4 */
2252 static size_t HUF_readDTableX6 (U32* DTable, const void* src, size_t srcSize)
2253 {
2254     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
2255     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
2256     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
2257     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
2258     U32* const rankStart = rankStart0+1;
2259     U32 tableLog, maxW, sizeOfSort, nbSymbols;
2260     rankVal_t rankVal;
2261     const U32 memLog = DTable[0];
2262     const BYTE* ip = (const BYTE*) src;
2263     size_t iSize = ip[0];
2264 
2265     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
2266     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
2267 
2268     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
2269     if (HUF_isError(iSize)) return iSize;
2270 
2271     /* check result */
2272     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable is too small */
2273 
2274     /* find maxWeight */
2275     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
2276         { if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
2277 
2278 
2279     /* Get start index of each weight */
2280     {
2281         U32 w, nextRankStart = 0;
2282         for (w=1; w<=maxW; w++)
2283         {
2284             U32 current = nextRankStart;
2285             nextRankStart += rankStats[w];
2286             rankStart[w] = current;
2287         }
2288         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
2289         sizeOfSort = nextRankStart;
2290     }
2291 
2292     /* sort symbols by weight */
2293     {
2294         U32 s;
2295         for (s=0; s<nbSymbols; s++)
2296         {
2297             U32 w = weightList[s];
2298             U32 r = rankStart[w]++;
2299             sortedSymbol[r].symbol = (BYTE)s;
2300             sortedSymbol[r].weight = (BYTE)w;
2301         }
2302         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
2303     }
2304 
2305     /* Build rankVal */
2306     {
2307         const U32 minBits = tableLog+1 - maxW;
2308         U32 nextRankVal = 0;
2309         U32 w, consumed;
2310         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
2311         U32* rankVal0 = rankVal[0];
2312         for (w=1; w<=maxW; w++)
2313         {
2314             U32 current = nextRankVal;
2315             nextRankVal += rankStats[w] << (w+rescale);
2316             rankVal0[w] = current;
2317         }
2318         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
2319         {
2320             U32* rankValPtr = rankVal[consumed];
2321             for (w = 1; w <= maxW; w++)
2322             {
2323                 rankValPtr[w] = rankVal0[w] >> consumed;
2324             }
2325         }
2326     }
2327 
2328 
2329     /* fill tables */
2330     {
2331         void* ptr = DTable+1;
2332         HUF_DDescX6* DDescription = (HUF_DDescX6*)(ptr);
2333         void* dSeqStart = DTable + 1 + ((size_t)1<<(memLog-1));
2334         HUF_DSeqX6* DSequence = (HUF_DSeqX6*)(dSeqStart);
2335         HUF_DSeqX6 DSeq;
2336         HUF_DDescX6 DDesc;
2337         DSeq.sequence = 0;
2338         DDesc.nbBits = 0;
2339         DDesc.nbBytes = 0;
2340         HUF_fillDTableX6LevelN(DDescription, DSequence, memLog,
2341                        (const U32 (*)[HUF_ABSOLUTEMAX_TABLELOG + 1])rankVal, 0, 1, maxW,
2342                        sortedSymbol, sizeOfSort, rankStart0,
2343                        tableLog+1, DSeq, DDesc);
2344     }
2345 
2346     return iSize;
2347 }
2348 
2349 
2350 static U32 HUF_decodeSymbolX6(void* op, BIT_DStream_t* DStream, const HUF_DDescX6* dd, const HUF_DSeqX6* ds, const U32 dtLog)
2351 {
2352     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2353     memcpy(op, ds+val, sizeof(HUF_DSeqX6));
2354     BIT_skipBits(DStream, dd[val].nbBits);
2355     return dd[val].nbBytes;
2356 }
2357 
2358 static U32 HUF_decodeLastSymbolsX6(void* op, const U32 maxL, BIT_DStream_t* DStream,
2359                                   const HUF_DDescX6* dd, const HUF_DSeqX6* ds, const U32 dtLog)
2360 {
2361     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2362     U32 length = dd[val].nbBytes;
2363     if (length <= maxL)
2364     {
2365         memcpy(op, ds+val, length);
2366         BIT_skipBits(DStream, dd[val].nbBits);
2367         return length;
2368     }
2369     memcpy(op, ds+val, maxL);
2370     if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
2371     {
2372         BIT_skipBits(DStream, dd[val].nbBits);
2373         if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2374             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 */
2375     }
2376     return maxL;
2377 }
2378 
2379 
2380 #define HUF_DECODE_SYMBOLX6_0(ptr, DStreamPtr) \
2381     ptr += HUF_decodeSymbolX6(ptr, DStreamPtr, dd, ds, dtLog)
2382 
2383 #define HUF_DECODE_SYMBOLX6_1(ptr, DStreamPtr) \
2384     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
2385         HUF_DECODE_SYMBOLX6_0(ptr, DStreamPtr)
2386 
2387 #define HUF_DECODE_SYMBOLX6_2(ptr, DStreamPtr) \
2388     if (MEM_64bits()) \
2389         HUF_DECODE_SYMBOLX6_0(ptr, DStreamPtr)
2390 
2391 static inline size_t HUF_decodeStreamX6(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const U32* DTable, const U32 dtLog)
2392 {
2393     const void* ddPtr = DTable+1;
2394     const HUF_DDescX6* dd = (const HUF_DDescX6*)(ddPtr);
2395     const void* dsPtr = DTable + 1 + ((size_t)1<<(dtLog-1));
2396     const HUF_DSeqX6* ds = (const HUF_DSeqX6*)(dsPtr);
2397     BYTE* const pStart = p;
2398 
2399     /* up to 16 symbols at a time */
2400     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-16))
2401     {
2402         HUF_DECODE_SYMBOLX6_2(p, bitDPtr);
2403         HUF_DECODE_SYMBOLX6_1(p, bitDPtr);
2404         HUF_DECODE_SYMBOLX6_2(p, bitDPtr);
2405         HUF_DECODE_SYMBOLX6_0(p, bitDPtr);
2406     }
2407 
2408     /* closer to the end, up to 4 symbols at a time */
2409     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
2410         HUF_DECODE_SYMBOLX6_0(p, bitDPtr);
2411 
2412     while (p <= pEnd-4)
2413         HUF_DECODE_SYMBOLX6_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2414 
2415     while (p < pEnd)
2416         p += HUF_decodeLastSymbolsX6(p, (U32)(pEnd-p), bitDPtr, dd, ds, dtLog);
2417 
2418     return p-pStart;
2419 }
2420 
2421 
2422 
2423 static size_t HUF_decompress4X6_usingDTable(
2424           void* dst,  size_t dstSize,
2425     const void* cSrc, size_t cSrcSize,
2426     const U32* DTable)
2427 {
2428     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2429 
2430     {
2431         const BYTE* const istart = (const BYTE*) cSrc;
2432         BYTE* const ostart = (BYTE*) dst;
2433         BYTE* const oend = ostart + dstSize;
2434 
2435         const U32 dtLog = DTable[0];
2436         const void* ddPtr = DTable+1;
2437         const HUF_DDescX6* dd = (const HUF_DDescX6*)(ddPtr);
2438         const void* dsPtr = DTable + 1 + ((size_t)1<<(dtLog-1));
2439         const HUF_DSeqX6* ds = (const HUF_DSeqX6*)(dsPtr);
2440         size_t errorCode;
2441 
2442         /* Init */
2443         BIT_DStream_t bitD1;
2444         BIT_DStream_t bitD2;
2445         BIT_DStream_t bitD3;
2446         BIT_DStream_t bitD4;
2447         const size_t length1 = MEM_readLE16(istart);
2448         const size_t length2 = MEM_readLE16(istart+2);
2449         const size_t length3 = MEM_readLE16(istart+4);
2450         size_t length4;
2451         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2452         const BYTE* const istart2 = istart1 + length1;
2453         const BYTE* const istart3 = istart2 + length2;
2454         const BYTE* const istart4 = istart3 + length3;
2455         const size_t segmentSize = (dstSize+3) / 4;
2456         BYTE* const opStart2 = ostart + segmentSize;
2457         BYTE* const opStart3 = opStart2 + segmentSize;
2458         BYTE* const opStart4 = opStart3 + segmentSize;
2459         BYTE* op1 = ostart;
2460         BYTE* op2 = opStart2;
2461         BYTE* op3 = opStart3;
2462         BYTE* op4 = opStart4;
2463         U32 endSignal;
2464 
2465         length4 = cSrcSize - (length1 + length2 + length3 + 6);
2466         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2467         errorCode = BIT_initDStream(&bitD1, istart1, length1);
2468         if (HUF_isError(errorCode)) return errorCode;
2469         errorCode = BIT_initDStream(&bitD2, istart2, length2);
2470         if (HUF_isError(errorCode)) return errorCode;
2471         errorCode = BIT_initDStream(&bitD3, istart3, length3);
2472         if (HUF_isError(errorCode)) return errorCode;
2473         errorCode = BIT_initDStream(&bitD4, istart4, length4);
2474         if (HUF_isError(errorCode)) return errorCode;
2475 
2476         /* 16-64 symbols per loop (4-16 symbols per stream) */
2477         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2478         for ( ; (op3 <= opStart4) && (endSignal==BIT_DStream_unfinished) && (op4<=(oend-16)) ; )
2479         {
2480             HUF_DECODE_SYMBOLX6_2(op1, &bitD1);
2481             HUF_DECODE_SYMBOLX6_2(op2, &bitD2);
2482             HUF_DECODE_SYMBOLX6_2(op3, &bitD3);
2483             HUF_DECODE_SYMBOLX6_2(op4, &bitD4);
2484             HUF_DECODE_SYMBOLX6_1(op1, &bitD1);
2485             HUF_DECODE_SYMBOLX6_1(op2, &bitD2);
2486             HUF_DECODE_SYMBOLX6_1(op3, &bitD3);
2487             HUF_DECODE_SYMBOLX6_1(op4, &bitD4);
2488             HUF_DECODE_SYMBOLX6_2(op1, &bitD1);
2489             HUF_DECODE_SYMBOLX6_2(op2, &bitD2);
2490             HUF_DECODE_SYMBOLX6_2(op3, &bitD3);
2491             HUF_DECODE_SYMBOLX6_2(op4, &bitD4);
2492             HUF_DECODE_SYMBOLX6_0(op1, &bitD1);
2493             HUF_DECODE_SYMBOLX6_0(op2, &bitD2);
2494             HUF_DECODE_SYMBOLX6_0(op3, &bitD3);
2495             HUF_DECODE_SYMBOLX6_0(op4, &bitD4);
2496 
2497             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2498         }
2499 
2500         /* check corruption */
2501         if (op1 > opStart2) return ERROR(corruption_detected);
2502         if (op2 > opStart3) return ERROR(corruption_detected);
2503         if (op3 > opStart4) return ERROR(corruption_detected);
2504         /* note : op4 supposed already verified within main loop */
2505 
2506         /* finish bitStreams one by one */
2507         HUF_decodeStreamX6(op1, &bitD1, opStart2, DTable, dtLog);
2508         HUF_decodeStreamX6(op2, &bitD2, opStart3, DTable, dtLog);
2509         HUF_decodeStreamX6(op3, &bitD3, opStart4, DTable, dtLog);
2510         HUF_decodeStreamX6(op4, &bitD4, oend,     DTable, dtLog);
2511 
2512         /* check */
2513         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
2514         if (!endSignal) return ERROR(corruption_detected);
2515 
2516         /* decoded size */
2517         return dstSize;
2518     }
2519 }
2520 
2521 
2522 static size_t HUF_decompress4X6 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2523 {
2524     HUF_CREATE_STATIC_DTABLEX6(DTable, HUF_MAX_TABLELOG);
2525     const BYTE* ip = (const BYTE*) cSrc;
2526 
2527     size_t hSize = HUF_readDTableX6 (DTable, cSrc, cSrcSize);
2528     if (HUF_isError(hSize)) return hSize;
2529     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2530     ip += hSize;
2531     cSrcSize -= hSize;
2532 
2533     return HUF_decompress4X6_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
2534 }
2535 
2536 
2537 /**********************************/
2538 /* Generic decompression selector */
2539 /**********************************/
2540 
2541 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
2542 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
2543 {
2544     /* single, double, quad */
2545     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
2546     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
2547     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
2548     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
2549     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
2550     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
2551     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
2552     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
2553     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
2554     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
2555     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
2556     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
2557     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
2558     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
2559     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
2560     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
2561 };
2562 
2563 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
2564 
2565 static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2566 {
2567     static const decompressionAlgo decompress[3] = { HUF_decompress4X2, HUF_decompress4X4, HUF_decompress4X6 };
2568     /* estimate decompression time */
2569     U32 Q;
2570     const U32 D256 = (U32)(dstSize >> 8);
2571     U32 Dtime[3];
2572     U32 algoNb = 0;
2573     int n;
2574 
2575     /* validation checks */
2576     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2577     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2578     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2579     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2580 
2581     /* decoder timing evaluation */
2582     Q = (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 since dstSize > cSrcSize */
2583     for (n=0; n<3; n++)
2584         Dtime[n] = algoTime[Q][n].tableTime + (algoTime[Q][n].decode256Time * D256);
2585 
2586     Dtime[1] += Dtime[1] >> 4; Dtime[2] += Dtime[2] >> 3; /* advantage to algorithms using less memory, for cache eviction */
2587 
2588     if (Dtime[1] < Dtime[0]) algoNb = 1;
2589     if (Dtime[2] < Dtime[algoNb]) algoNb = 2;
2590 
2591     return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
2592 
2593     //return HUF_decompress4X2(dst, dstSize, cSrc, cSrcSize);   /* multi-streams single-symbol decoding */
2594     //return HUF_decompress4X4(dst, dstSize, cSrc, cSrcSize);   /* multi-streams double-symbols decoding */
2595     //return HUF_decompress4X6(dst, dstSize, cSrc, cSrcSize);   /* multi-streams quad-symbols decoding */
2596 }
2597 /*
2598     zstd - standard compression library
2599     Copyright (C) 2014-2015, Yann Collet.
2600 
2601     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2602 
2603     Redistribution and use in source and binary forms, with or without
2604     modification, are permitted provided that the following conditions are
2605     met:
2606     * Redistributions of source code must retain the above copyright
2607     notice, this list of conditions and the following disclaimer.
2608     * Redistributions in binary form must reproduce the above
2609     copyright notice, this list of conditions and the following disclaimer
2610     in the documentation and/or other materials provided with the
2611     distribution.
2612     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2613     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2614     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2615     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2616     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2617     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2618     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2619     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2620     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2621     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2622     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2623 
2624     You can contact the author at :
2625     - zstd source repository : https://github.com/Cyan4973/zstd
2626     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
2627 */
2628 
2629 /* ***************************************************************
2630 *  Tuning parameters
2631 *****************************************************************/
2632 /*!
2633 *  MEMORY_USAGE :
2634 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
2635 *  Increasing memory usage improves compression ratio
2636 *  Reduced memory usage can improve speed, due to cache effect
2637 */
2638 #define ZSTD_MEMORY_USAGE 17
2639 
2640 /*!
2641  * HEAPMODE :
2642  * Select how default compression functions will allocate memory for their hash table,
2643  * in memory stack (0, fastest), or in memory heap (1, requires malloc())
2644  * Note that compression context is fairly large, as a consequence heap memory is recommended.
2645  */
2646 #ifndef ZSTD_HEAPMODE
2647 #  define ZSTD_HEAPMODE 1
2648 #endif /* ZSTD_HEAPMODE */
2649 
2650 /*!
2651 *  LEGACY_SUPPORT :
2652 *  decompressor can decode older formats (starting from Zstd 0.1+)
2653 */
2654 #ifndef ZSTD_LEGACY_SUPPORT
2655 #  define ZSTD_LEGACY_SUPPORT 1
2656 #endif
2657 
2658 
2659 /* *******************************************************
2660 *  Includes
2661 *********************************************************/
2662 #include <stdlib.h>      /* calloc */
2663 #include <string.h>      /* memcpy, memmove */
2664 #include <stdio.h>       /* debug : printf */
2665 
2666 
2667 /* *******************************************************
2668 *  Compiler specifics
2669 *********************************************************/
2670 #ifdef __AVX2__
2671 #  include <immintrin.h>   /* AVX2 intrinsics */
2672 #endif
2673 
2674 #ifdef _MSC_VER    /* Visual Studio */
2675 #  include <intrin.h>                    /* For Visual 2005 */
2676 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
2677 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
2678 #endif
2679 
2680 
2681 /* *******************************************************
2682 *  Constants
2683 *********************************************************/
2684 #define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
2685 #define HASH_TABLESIZE (1 << HASH_LOG)
2686 #define HASH_MASK (HASH_TABLESIZE - 1)
2687 
2688 #define KNUTH 2654435761
2689 
2690 #define BIT7 128
2691 #define BIT6  64
2692 #define BIT5  32
2693 #define BIT4  16
2694 #define BIT1   2
2695 #define BIT0   1
2696 
2697 #define KB *(1 <<10)
2698 #define MB *(1 <<20)
2699 #define GB *(1U<<30)
2700 
2701 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
2702 #define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
2703 #define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
2704 #define IS_RAW BIT0
2705 #define IS_RLE BIT1
2706 
2707 #define WORKPLACESIZE (BLOCKSIZE*3)
2708 #define MINMATCH 4
2709 #define MLbits   7
2710 #define LLbits   6
2711 #define Offbits  5
2712 #define MaxML  ((1<<MLbits )-1)
2713 #define MaxLL  ((1<<LLbits )-1)
2714 #define MaxOff   31
2715 #define LitFSELog  11
2716 #define MLFSELog   10
2717 #define LLFSELog   10
2718 #define OffFSELog   9
2719 #define MAX(a,b) ((a)<(b)?(b):(a))
2720 #define MaxSeq MAX(MaxLL, MaxML)
2721 
2722 #define LITERAL_NOENTROPY 63
2723 #define COMMAND_NOENTROPY 7   /* to remove */
2724 
2725 static const size_t ZSTD_blockHeaderSize = 3;
2726 static const size_t ZSTD_frameHeaderSize = 4;
2727 
2728 
2729 /* *******************************************************
2730 *  Memory operations
2731 **********************************************************/
2732 static void   ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
2733 
2734 static void   ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
2735 
2736 #define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }
2737 
2738 /*! ZSTD_wildcopy : custom version of memcpy(), can copy up to 7-8 bytes too many */
2739 static void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length)
2740 {
2741     const BYTE* ip = (const BYTE*)src;
2742     BYTE* op = (BYTE*)dst;
2743     BYTE* const oend = op + length;
2744     do COPY8(op, ip) while (op < oend);
2745 }
2746 
2747 
2748 /* **************************************
2749 *  Local structures
2750 ****************************************/
2751 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
2752 
2753 typedef struct
2754 {
2755     blockType_t blockType;
2756     U32 origSize;
2757 } blockProperties_t;
2758 
2759 typedef struct {
2760     void* buffer;
2761     U32*  offsetStart;
2762     U32*  offset;
2763     BYTE* offCodeStart;
2764     BYTE* offCode;
2765     BYTE* litStart;
2766     BYTE* lit;
2767     BYTE* litLengthStart;
2768     BYTE* litLength;
2769     BYTE* matchLengthStart;
2770     BYTE* matchLength;
2771     BYTE* dumpsStart;
2772     BYTE* dumps;
2773 } seqStore_t;
2774 
2775 
2776 /* *************************************
2777 *  Error Management
2778 ***************************************/
2779 /*! ZSTD_isError
2780 *   tells if a return value is an error code */
2781 static unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
2782 
2783 
2784 
2785 /* *************************************************************
2786 *   Decompression section
2787 ***************************************************************/
2788 struct ZSTD_DCtx_s
2789 {
2790     U32 LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
2791     U32 OffTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
2792     U32 MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
2793     void* previousDstEnd;
2794     void* base;
2795     size_t expected;
2796     blockType_t bType;
2797     U32 phase;
2798     const BYTE* litPtr;
2799     size_t litSize;
2800     BYTE litBuffer[BLOCKSIZE + 8 /* margin for wildcopy */];
2801 };   /* typedef'd to ZSTD_Dctx within "zstd_static.h" */
2802 
2803 
2804 static size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
2805 {
2806     const BYTE* const in = (const BYTE* const)src;
2807     BYTE headerFlags;
2808     U32 cSize;
2809 
2810     if (srcSize < 3) return ERROR(srcSize_wrong);
2811 
2812     headerFlags = *in;
2813     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
2814 
2815     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
2816     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
2817 
2818     if (bpPtr->blockType == bt_end) return 0;
2819     if (bpPtr->blockType == bt_rle) return 1;
2820     return cSize;
2821 }
2822 
2823 static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
2824 {
2825     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
2826     memcpy(dst, src, srcSize);
2827     return srcSize;
2828 }
2829 
2830 
2831 /** ZSTD_decompressLiterals
2832     @return : nb of bytes read from src, or an error code*/
2833 static size_t ZSTD_decompressLiterals(void* dst, size_t* maxDstSizePtr,
2834                                 const void* src, size_t srcSize)
2835 {
2836     const BYTE* ip = (const BYTE*)src;
2837 
2838     const size_t litSize = (MEM_readLE32(src) & 0x1FFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2839     const size_t litCSize = (MEM_readLE32(ip+2) & 0xFFFFFF) >> 5;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2840 
2841     if (litSize > *maxDstSizePtr) return ERROR(corruption_detected);
2842     if (litCSize + 5 > srcSize) return ERROR(corruption_detected);
2843 
2844     if (HUF_isError(HUF_decompress(dst, litSize, ip+5, litCSize))) return ERROR(corruption_detected);
2845 
2846     *maxDstSizePtr = litSize;
2847     return litCSize + 5;
2848 }
2849 
2850 
2851 /** ZSTD_decodeLiteralsBlock
2852     @return : nb of bytes read from src (< srcSize )*/
2853 static size_t ZSTD_decodeLiteralsBlock(void* ctx,
2854                           const void* src, size_t srcSize)
2855 {
2856     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
2857     const BYTE* const istart = (const BYTE* const)src;
2858 
2859     /* any compressed block with literals segment must be at least this size */
2860     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
2861 
2862     switch(*istart & 3)
2863     {
2864     default:
2865     case 0:
2866         {
2867             size_t litSize = BLOCKSIZE;
2868             const size_t readSize = ZSTD_decompressLiterals(dctx->litBuffer, &litSize, src, srcSize);
2869             dctx->litPtr = dctx->litBuffer;
2870             dctx->litSize = litSize;
2871             memset(dctx->litBuffer + dctx->litSize, 0, 8);
2872             return readSize;   /* works if it's an error too */
2873         }
2874     case IS_RAW:
2875         {
2876             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2877             if (litSize > srcSize-11)   /* risk of reading too far with wildcopy */
2878             {
2879                 if (litSize > srcSize-3) return ERROR(corruption_detected);
2880                 memcpy(dctx->litBuffer, istart, litSize);
2881                 dctx->litPtr = dctx->litBuffer;
2882                 dctx->litSize = litSize;
2883                 memset(dctx->litBuffer + dctx->litSize, 0, 8);
2884                 return litSize+3;
2885             }
2886             /* direct reference into compressed stream */
2887             dctx->litPtr = istart+3;
2888             dctx->litSize = litSize;
2889             return litSize+3;
2890         }
2891     case IS_RLE:
2892         {
2893             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2894             if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2895             memset(dctx->litBuffer, istart[3], litSize + 8);
2896             dctx->litPtr = dctx->litBuffer;
2897             dctx->litSize = litSize;
2898             return 4;
2899         }
2900     }
2901 }
2902 
2903 
2904 static size_t ZSTD_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
2905                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
2906                          const void* src, size_t srcSize)
2907 {
2908     const BYTE* const istart = (const BYTE* const)src;
2909     const BYTE* ip = istart;
2910     const BYTE* const iend = istart + srcSize;
2911     U32 LLtype, Offtype, MLtype;
2912     U32 LLlog, Offlog, MLlog;
2913     size_t dumpsLength;
2914 
2915     /* check */
2916     if (srcSize < 5) return ERROR(srcSize_wrong);
2917 
2918     /* SeqHead */
2919     *nbSeq = MEM_readLE16(ip); ip+=2;
2920     LLtype  = *ip >> 6;
2921     Offtype = (*ip >> 4) & 3;
2922     MLtype  = (*ip >> 2) & 3;
2923     if (*ip & 2)
2924     {
2925         dumpsLength  = ip[2];
2926         dumpsLength += ip[1] << 8;
2927         ip += 3;
2928     }
2929     else
2930     {
2931         dumpsLength  = ip[1];
2932         dumpsLength += (ip[0] & 1) << 8;
2933         ip += 2;
2934     }
2935     *dumpsPtr = ip;
2936     ip += dumpsLength;
2937     *dumpsLengthPtr = dumpsLength;
2938 
2939     /* check */
2940     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
2941 
2942     /* sequences */
2943     {
2944         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL and MaxOff */
2945         size_t headerSize;
2946 
2947         /* Build DTables */
2948         switch(LLtype)
2949         {
2950         case bt_rle :
2951             LLlog = 0;
2952             FSE_buildDTable_rle(DTableLL, *ip++); break;
2953         case bt_raw :
2954             LLlog = LLbits;
2955             FSE_buildDTable_raw(DTableLL, LLbits); break;
2956         default :
2957             {   U32 max = MaxLL;
2958                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
2959                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2960                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
2961                 ip += headerSize;
2962                 FSE_buildDTable(DTableLL, norm, max, LLlog);
2963         }   }
2964 
2965         switch(Offtype)
2966         {
2967         case bt_rle :
2968             Offlog = 0;
2969             if (ip > iend-2) return ERROR(srcSize_wrong);   /* min : "raw", hence no header, but at least xxLog bits */
2970             FSE_buildDTable_rle(DTableOffb, *ip++ & MaxOff); /* if *ip > MaxOff, data is corrupted */
2971             break;
2972         case bt_raw :
2973             Offlog = Offbits;
2974             FSE_buildDTable_raw(DTableOffb, Offbits); break;
2975         default :
2976             {   U32 max = MaxOff;
2977                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
2978                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2979                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
2980                 ip += headerSize;
2981                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
2982         }   }
2983 
2984         switch(MLtype)
2985         {
2986         case bt_rle :
2987             MLlog = 0;
2988             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
2989             FSE_buildDTable_rle(DTableML, *ip++); break;
2990         case bt_raw :
2991             MLlog = MLbits;
2992             FSE_buildDTable_raw(DTableML, MLbits); break;
2993         default :
2994             {   U32 max = MaxML;
2995                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
2996                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2997                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
2998                 ip += headerSize;
2999                 FSE_buildDTable(DTableML, norm, max, MLlog);
3000     }   }   }
3001 
3002     return ip-istart;
3003 }
3004 
3005 
3006 typedef struct {
3007     size_t litLength;
3008     size_t offset;
3009     size_t matchLength;
3010 } seq_t;
3011 
3012 typedef struct {
3013     BIT_DStream_t DStream;
3014     FSE_DState_t stateLL;
3015     FSE_DState_t stateOffb;
3016     FSE_DState_t stateML;
3017     size_t prevOffset;
3018     const BYTE* dumps;
3019     const BYTE* dumpsEnd;
3020 } seqState_t;
3021 
3022 
3023 static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
3024 {
3025     size_t litLength;
3026     size_t prevOffset;
3027     size_t offset;
3028     size_t matchLength;
3029     const BYTE* dumps = seqState->dumps;
3030     const BYTE* const de = seqState->dumpsEnd;
3031 
3032     /* Literal length */
3033     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
3034     prevOffset = litLength ? seq->offset : seqState->prevOffset;
3035     seqState->prevOffset = seq->offset;
3036     if (litLength == MaxLL)
3037     {
3038         U32 add = *dumps++;
3039         if (add < 255) litLength += add;
3040         else
3041         {
3042             litLength = MEM_readLE32(dumps) & 0xFFFFFF;  /* no pb : dumps is always followed by seq tables > 1 byte */
3043             dumps += 3;
3044         }
3045         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
3046     }
3047 
3048     /* Offset */
3049     {
3050         static const size_t offsetPrefix[MaxOff+1] = {  /* note : size_t faster than U32 */
3051                 1 /*fake*/, 1, 2, 4, 8, 16, 32, 64, 128, 256,
3052                 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144,
3053                 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, /*fake*/ 1, 1, 1, 1, 1 };
3054         U32 offsetCode, nbBits;
3055         offsetCode = FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream));   /* <= maxOff, by table construction */
3056         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
3057         nbBits = offsetCode - 1;
3058         if (offsetCode==0) nbBits = 0;   /* cmove */
3059         offset = offsetPrefix[offsetCode] + BIT_readBits(&(seqState->DStream), nbBits);
3060         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
3061         if (offsetCode==0) offset = prevOffset;   /* cmove */
3062     }
3063 
3064     /* MatchLength */
3065     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
3066     if (matchLength == MaxML)
3067     {
3068         U32 add = *dumps++;
3069         if (add < 255) matchLength += add;
3070         else
3071         {
3072             matchLength = MEM_readLE32(dumps) & 0xFFFFFF;  /* no pb : dumps is always followed by seq tables > 1 byte */
3073             dumps += 3;
3074         }
3075         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
3076     }
3077     matchLength += MINMATCH;
3078 
3079     /* save result */
3080     seq->litLength = litLength;
3081     seq->offset = offset;
3082     seq->matchLength = matchLength;
3083     seqState->dumps = dumps;
3084 }
3085 
3086 
3087 static size_t ZSTD_execSequence(BYTE* op,
3088                                 seq_t sequence,
3089                                 const BYTE** litPtr, const BYTE* const litLimit,
3090                                 BYTE* const base, BYTE* const oend)
3091 {
3092     static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
3093     static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11};   /* substracted */
3094     const BYTE* const ostart = op;
3095     BYTE* const oLitEnd = op + sequence.litLength;
3096     BYTE* const oMatchEnd = op + sequence.litLength + sequence.matchLength;   /* risk : address space overflow (32-bits) */
3097     BYTE* const oend_8 = oend-8;
3098     const BYTE* const litEnd = *litPtr + sequence.litLength;
3099 
3100     /* checks */
3101     if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall);   /* last match must start at a minimum distance of 8 from oend */
3102     if (oMatchEnd > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
3103     if (litEnd > litLimit) return ERROR(corruption_detected);   /* overRead beyond lit buffer */
3104 
3105     /* copy Literals */
3106     ZSTD_wildcopy(op, *litPtr, sequence.litLength);   /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
3107     op = oLitEnd;
3108     *litPtr = litEnd;   /* update for next sequence */
3109 
3110     /* copy Match */
3111     {
3112         const BYTE* match = op - sequence.offset;
3113 
3114         /* check */
3115         if (sequence.offset > (size_t)op) return ERROR(corruption_detected);   /* address space overflow test (this test seems kept by clang optimizer) */
3116         //if (match > op) return ERROR(corruption_detected);   /* address space overflow test (is clang optimizer removing this test ?) */
3117         if (match < base) return ERROR(corruption_detected);
3118 
3119         /* close range match, overlap */
3120         if (sequence.offset < 8)
3121         {
3122             const int dec64 = dec64table[sequence.offset];
3123             op[0] = match[0];
3124             op[1] = match[1];
3125             op[2] = match[2];
3126             op[3] = match[3];
3127             match += dec32table[sequence.offset];
3128             ZSTD_copy4(op+4, match);
3129             match -= dec64;
3130         }
3131         else
3132         {
3133             ZSTD_copy8(op, match);
3134         }
3135         op += 8; match += 8;
3136 
3137         if (oMatchEnd > oend-(16-MINMATCH))
3138         {
3139             if (op < oend_8)
3140             {
3141                 ZSTD_wildcopy(op, match, oend_8 - op);
3142                 match += oend_8 - op;
3143                 op = oend_8;
3144             }
3145             while (op < oMatchEnd) *op++ = *match++;
3146         }
3147         else
3148         {
3149             ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
3150         }
3151     }
3152 
3153     return oMatchEnd - ostart;
3154 }
3155 
3156 static size_t ZSTD_decompressSequences(
3157                                void* ctx,
3158                                void* dst, size_t maxDstSize,
3159                          const void* seqStart, size_t seqSize)
3160 {
3161     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
3162     const BYTE* ip = (const BYTE*)seqStart;
3163     const BYTE* const iend = ip + seqSize;
3164     BYTE* const ostart = (BYTE* const)dst;
3165     BYTE* op = ostart;
3166     BYTE* const oend = ostart + maxDstSize;
3167     size_t errorCode, dumpsLength;
3168     const BYTE* litPtr = dctx->litPtr;
3169     const BYTE* const litEnd = litPtr + dctx->litSize;
3170     int nbSeq;
3171     const BYTE* dumps;
3172     U32* DTableLL = dctx->LLTable;
3173     U32* DTableML = dctx->MLTable;
3174     U32* DTableOffb = dctx->OffTable;
3175     BYTE* const base = (BYTE*) (dctx->base);
3176 
3177     /* Build Decoding Tables */
3178     errorCode = ZSTD_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
3179                                       DTableLL, DTableML, DTableOffb,
3180                                       ip, iend-ip);
3181     if (ZSTD_isError(errorCode)) return errorCode;
3182     ip += errorCode;
3183 
3184     /* Regen sequences */
3185     {
3186         seq_t sequence;
3187         seqState_t seqState;
3188 
3189         memset(&sequence, 0, sizeof(sequence));
3190         seqState.dumps = dumps;
3191         seqState.dumpsEnd = dumps + dumpsLength;
3192         seqState.prevOffset = 1;
3193         errorCode = BIT_initDStream(&(seqState.DStream), ip, iend-ip);
3194         if (ERR_isError(errorCode)) return ERROR(corruption_detected);
3195         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
3196         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
3197         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
3198 
3199         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (nbSeq>0) ; )
3200         {
3201             size_t oneSeqSize;
3202             nbSeq--;
3203             ZSTD_decodeSequence(&sequence, &seqState);
3204             oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend);
3205             if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
3206             op += oneSeqSize;
3207         }
3208 
3209         /* check if reached exact end */
3210         if ( !BIT_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* requested too much : data is corrupted */
3211         if (nbSeq<0) return ERROR(corruption_detected);   /* requested too many sequences : data is corrupted */
3212 
3213         /* last literal segment */
3214         {
3215             size_t lastLLSize = litEnd - litPtr;
3216             if (litPtr > litEnd) return ERROR(corruption_detected);
3217             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
3218             if (op != litPtr) memmove(op, litPtr, lastLLSize);
3219             op += lastLLSize;
3220         }
3221     }
3222 
3223     return op-ostart;
3224 }
3225 
3226 
3227 static size_t ZSTD_decompressBlock(
3228                             void* ctx,
3229                             void* dst, size_t maxDstSize,
3230                       const void* src, size_t srcSize)
3231 {
3232     /* blockType == blockCompressed */
3233     const BYTE* ip = (const BYTE*)src;
3234 
3235     /* Decode literals sub-block */
3236     size_t litCSize = ZSTD_decodeLiteralsBlock(ctx, src, srcSize);
3237     if (ZSTD_isError(litCSize)) return litCSize;
3238     ip += litCSize;
3239     srcSize -= litCSize;
3240 
3241     return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize);
3242 }
3243 
3244 
3245 static size_t ZSTD_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3246 {
3247     const BYTE* ip = (const BYTE*)src;
3248     const BYTE* iend = ip + srcSize;
3249     BYTE* const ostart = (BYTE* const)dst;
3250     BYTE* op = ostart;
3251     BYTE* const oend = ostart + maxDstSize;
3252     size_t remainingSize = srcSize;
3253     U32 magicNumber;
3254     blockProperties_t blockProperties;
3255 
3256     /* Frame Header */
3257     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
3258     magicNumber = MEM_readLE32(src);
3259     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
3260     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
3261 
3262     /* Loop on each block */
3263     while (1)
3264     {
3265         size_t decodedSize=0;
3266         size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &blockProperties);
3267         if (ZSTD_isError(cBlockSize)) return cBlockSize;
3268 
3269         ip += ZSTD_blockHeaderSize;
3270         remainingSize -= ZSTD_blockHeaderSize;
3271         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
3272 
3273         switch(blockProperties.blockType)
3274         {
3275         case bt_compressed:
3276             decodedSize = ZSTD_decompressBlock(ctx, op, oend-op, ip, cBlockSize);
3277             break;
3278         case bt_raw :
3279             decodedSize = ZSTD_copyUncompressedBlock(op, oend-op, ip, cBlockSize);
3280             break;
3281         case bt_rle :
3282             return ERROR(GENERIC);   /* not yet supported */
3283             break;
3284         case bt_end :
3285             /* end of frame */
3286             if (remainingSize) return ERROR(srcSize_wrong);
3287             break;
3288         default:
3289             return ERROR(GENERIC);   /* impossible */
3290         }
3291         if (cBlockSize == 0) break;   /* bt_end */
3292 
3293         if (ZSTD_isError(decodedSize)) return decodedSize;
3294         op += decodedSize;
3295         ip += cBlockSize;
3296         remainingSize -= cBlockSize;
3297     }
3298 
3299     return op-ostart;
3300 }
3301 
3302 static size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3303 {
3304     ZSTD_DCtx ctx;
3305     ctx.base = dst;
3306     return ZSTD_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
3307 }
3308 
3309 static size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
3310 {
3311 
3312     const BYTE* ip = (const BYTE*)src;
3313     size_t remainingSize = srcSize;
3314     U32 magicNumber;
3315     blockProperties_t blockProperties;
3316 
3317     /* Frame Header */
3318     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
3319     magicNumber = MEM_readLE32(src);
3320     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
3321     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
3322 
3323     /* Loop on each block */
3324     while (1)
3325     {
3326         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
3327         if (ZSTD_isError(cBlockSize)) return cBlockSize;
3328 
3329         ip += ZSTD_blockHeaderSize;
3330         remainingSize -= ZSTD_blockHeaderSize;
3331         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
3332 
3333         if (cBlockSize == 0) break;   /* bt_end */
3334 
3335         ip += cBlockSize;
3336         remainingSize -= cBlockSize;
3337     }
3338 
3339     return ip - (const BYTE*)src;
3340 }
3341 
3342 /*******************************
3343 *  Streaming Decompression API
3344 *******************************/
3345 
3346 static size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx)
3347 {
3348     dctx->expected = ZSTD_frameHeaderSize;
3349     dctx->phase = 0;
3350     dctx->previousDstEnd = NULL;
3351     dctx->base = NULL;
3352     return 0;
3353 }
3354 
3355 static ZSTD_DCtx* ZSTD_createDCtx(void)
3356 {
3357     ZSTD_DCtx* dctx = (ZSTD_DCtx*)malloc(sizeof(ZSTD_DCtx));
3358     if (dctx==NULL) return NULL;
3359     ZSTD_resetDCtx(dctx);
3360     return dctx;
3361 }
3362 
3363 static size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
3364 {
3365     free(dctx);
3366     return 0;
3367 }
3368 
3369 static size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx)
3370 {
3371     return dctx->expected;
3372 }
3373 
3374 static size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3375 {
3376     /* Sanity check */
3377     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
3378     if (dst != ctx->previousDstEnd)  /* not contiguous */
3379         ctx->base = dst;
3380 
3381     /* Decompress : frame header */
3382     if (ctx->phase == 0)
3383     {
3384         /* Check frame magic header */
3385         U32 magicNumber = MEM_readLE32(src);
3386         if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
3387         ctx->phase = 1;
3388         ctx->expected = ZSTD_blockHeaderSize;
3389         return 0;
3390     }
3391 
3392     /* Decompress : block header */
3393     if (ctx->phase == 1)
3394     {
3395         blockProperties_t bp;
3396         size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
3397         if (ZSTD_isError(blockSize)) return blockSize;
3398         if (bp.blockType == bt_end)
3399         {
3400             ctx->expected = 0;
3401             ctx->phase = 0;
3402         }
3403         else
3404         {
3405             ctx->expected = blockSize;
3406             ctx->bType = bp.blockType;
3407             ctx->phase = 2;
3408         }
3409 
3410         return 0;
3411     }
3412 
3413     /* Decompress : block content */
3414     {
3415         size_t rSize;
3416         switch(ctx->bType)
3417         {
3418         case bt_compressed:
3419             rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
3420             break;
3421         case bt_raw :
3422             rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize);
3423             break;
3424         case bt_rle :
3425             return ERROR(GENERIC);   /* not yet handled */
3426             break;
3427         case bt_end :   /* should never happen (filtered at phase 1) */
3428             rSize = 0;
3429             break;
3430         default:
3431             return ERROR(GENERIC);
3432         }
3433         ctx->phase = 1;
3434         ctx->expected = ZSTD_blockHeaderSize;
3435         ctx->previousDstEnd = (void*)( ((char*)dst) + rSize);
3436         return rSize;
3437     }
3438 
3439 }
3440 
3441 
3442 /* wrapper layer */
3443 
3444 unsigned ZSTDv02_isError(size_t code)
3445 {
3446     return ZSTD_isError(code);
3447 }
3448 
3449 size_t ZSTDv02_decompress( void* dst, size_t maxOriginalSize,
3450                      const void* src, size_t compressedSize)
3451 {
3452     return ZSTD_decompress(dst, maxOriginalSize, src, compressedSize);
3453 }
3454 
3455 size_t ZSTDv02_findFrameCompressedSize(const void *src, size_t compressedSize)
3456 {
3457     return ZSTD_findFrameCompressedSize(src, compressedSize);
3458 }
3459 
3460 ZSTDv02_Dctx* ZSTDv02_createDCtx(void)
3461 {
3462     return (ZSTDv02_Dctx*)ZSTD_createDCtx();
3463 }
3464 
3465 size_t ZSTDv02_freeDCtx(ZSTDv02_Dctx* dctx)
3466 {
3467     return ZSTD_freeDCtx((ZSTD_DCtx*)dctx);
3468 }
3469 
3470 size_t ZSTDv02_resetDCtx(ZSTDv02_Dctx* dctx)
3471 {
3472     return ZSTD_resetDCtx((ZSTD_DCtx*)dctx);
3473 }
3474 
3475 size_t ZSTDv02_nextSrcSizeToDecompress(ZSTDv02_Dctx* dctx)
3476 {
3477     return ZSTD_nextSrcSizeToDecompress((ZSTD_DCtx*)dctx);
3478 }
3479 
3480 size_t ZSTDv02_decompressContinue(ZSTDv02_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3481 {
3482     return ZSTD_decompressContinue((ZSTD_DCtx*)dctx, dst, maxDstSize, src, srcSize);
3483 }
3484