xref: /freebsd/sys/contrib/zstd/lib/legacy/zstd_v02.c (revision 2b8331622f0b212cf3bb4fc4914a501e5321d506)
1 /*
2  * Copyright (c) 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 "../common/error_private.h"
15 
16 
17 /******************************************
18 *  Compiler-specific
19 ******************************************/
20 #if defined(_MSC_VER)   /* Visual Studio */
21 #   include <stdlib.h>  /* _byteswap_ulong */
22 #   include <intrin.h>  /* _byteswap_* */
23 #endif
24 
25 
26 /* ******************************************************************
27    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 # if defined(_AIX)
93 #  include <inttypes.h>
94 # else
95 #  include <stdint.h> /* intptr_t */
96 # endif
97   typedef  uint8_t BYTE;
98   typedef uint16_t U16;
99   typedef  int16_t S16;
100   typedef uint32_t U32;
101   typedef  int32_t S32;
102   typedef uint64_t U64;
103   typedef  int64_t S64;
104 #else
105   typedef unsigned char       BYTE;
106   typedef unsigned short      U16;
107   typedef   signed short      S16;
108   typedef unsigned int        U32;
109   typedef   signed int        S32;
110   typedef unsigned long long  U64;
111   typedef   signed long long  S64;
112 #endif
113 
114 
115 /****************************************************************
116 *  Memory I/O
117 *****************************************************************/
118 /* MEM_FORCE_MEMORY_ACCESS
119  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
120  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
121  * The below switch allow to select different access method for improved performance.
122  * Method 0 (default) : use `memcpy()`. Safe and portable.
123  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
124  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
125  * Method 2 : direct access. This method is portable but violate C standard.
126  *            It can generate buggy code on targets generating assembly depending on alignment.
127  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
128  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
129  * Prefer these methods in priority order (0 > 1 > 2)
130  */
131 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
132 #  if defined(__INTEL_COMPILER) || defined(__GNUC__) || defined(__ICCARM__)
133 #    define MEM_FORCE_MEMORY_ACCESS 1
134 #  endif
135 #endif
136 
137 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
138 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
139 
140 MEM_STATIC unsigned MEM_isLittleEndian(void)
141 {
142     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
143     return one.c[0];
144 }
145 
146 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
147 
148 /* violates C standard on structure alignment.
149 Only use if no other choice to achieve best performance on target platform */
150 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
151 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
152 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
153 
154 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
155 
156 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
157 
158 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
159 /* currently only defined for gcc and icc */
160 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
161 
162 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
163 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
164 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
165 
166 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
167 
168 #else
169 
170 /* default method, safe and standard.
171    can sometimes prove slower */
172 
173 MEM_STATIC U16 MEM_read16(const void* memPtr)
174 {
175     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
176 }
177 
178 MEM_STATIC U32 MEM_read32(const void* memPtr)
179 {
180     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
181 }
182 
183 MEM_STATIC U64 MEM_read64(const void* memPtr)
184 {
185     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
186 }
187 
188 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
189 {
190     memcpy(memPtr, &value, sizeof(value));
191 }
192 
193 #endif /* MEM_FORCE_MEMORY_ACCESS */
194 
195 
196 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
197 {
198     if (MEM_isLittleEndian())
199         return MEM_read16(memPtr);
200     else
201     {
202         const BYTE* p = (const BYTE*)memPtr;
203         return (U16)(p[0] + (p[1]<<8));
204     }
205 }
206 
207 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
208 {
209     if (MEM_isLittleEndian())
210     {
211         MEM_write16(memPtr, val);
212     }
213     else
214     {
215         BYTE* p = (BYTE*)memPtr;
216         p[0] = (BYTE)val;
217         p[1] = (BYTE)(val>>8);
218     }
219 }
220 
221 MEM_STATIC U32 MEM_readLE24(const void* memPtr)
222 {
223     return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
224 }
225 
226 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
227 {
228     if (MEM_isLittleEndian())
229         return MEM_read32(memPtr);
230     else
231     {
232         const BYTE* p = (const BYTE*)memPtr;
233         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
234     }
235 }
236 
237 
238 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
239 {
240     if (MEM_isLittleEndian())
241         return MEM_read64(memPtr);
242     else
243     {
244         const BYTE* p = (const BYTE*)memPtr;
245         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
246                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
247     }
248 }
249 
250 
251 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
252 {
253     if (MEM_32bits())
254         return (size_t)MEM_readLE32(memPtr);
255     else
256         return (size_t)MEM_readLE64(memPtr);
257 }
258 
259 #if defined (__cplusplus)
260 }
261 #endif
262 
263 #endif /* MEM_H_MODULE */
264 
265 
266 /* ******************************************************************
267    bitstream
268    Part of NewGen Entropy library
269    header file (to include)
270    Copyright (C) 2013-2015, Yann Collet.
271 
272    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
273 
274    Redistribution and use in source and binary forms, with or without
275    modification, are permitted provided that the following conditions are
276    met:
277 
278        * Redistributions of source code must retain the above copyright
279    notice, this list of conditions and the following disclaimer.
280        * Redistributions in binary form must reproduce the above
281    copyright notice, this list of conditions and the following disclaimer
282    in the documentation and/or other materials provided with the
283    distribution.
284 
285    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
286    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
287    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
288    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
289    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
290    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
291    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
292    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
293    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
294    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
295    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
296 
297    You can contact the author at :
298    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
299    - Public forum : https://groups.google.com/forum/#!forum/lz4c
300 ****************************************************************** */
301 #ifndef BITSTREAM_H_MODULE
302 #define BITSTREAM_H_MODULE
303 
304 #if defined (__cplusplus)
305 extern "C" {
306 #endif
307 
308 
309 /*
310 *  This API consists of small unitary functions, which highly benefit from being inlined.
311 *  Since link-time-optimization is not available for all compilers,
312 *  these functions are defined into a .h to be included.
313 */
314 
315 
316 /**********************************************
317 *  bitStream decompression API (read backward)
318 **********************************************/
319 typedef struct
320 {
321     size_t   bitContainer;
322     unsigned bitsConsumed;
323     const char* ptr;
324     const char* start;
325 } BIT_DStream_t;
326 
327 typedef enum { BIT_DStream_unfinished = 0,
328                BIT_DStream_endOfBuffer = 1,
329                BIT_DStream_completed = 2,
330                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
331                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
332 
333 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
334 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
335 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
336 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
337 
338 
339 /******************************************
340 *  unsafe API
341 ******************************************/
342 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
343 /* faster, but works only if nbBits >= 1 */
344 
345 
346 
347 /****************************************************************
348 *  Helper functions
349 ****************************************************************/
350 MEM_STATIC unsigned BIT_highbit32 (U32 val)
351 {
352 #   if defined(_MSC_VER)   /* Visual */
353     unsigned long r;
354     return _BitScanReverse(&r, val) ? (unsigned)r : 0;
355 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
356     return __builtin_clz (val) ^ 31;
357 #   else   /* Software version */
358     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 };
359     U32 v = val;
360     unsigned r;
361     v |= v >> 1;
362     v |= v >> 2;
363     v |= v >> 4;
364     v |= v >> 8;
365     v |= v >> 16;
366     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
367     return r;
368 #   endif
369 }
370 
371 
372 
373 /**********************************************************
374 * bitStream decoding
375 **********************************************************/
376 
377 /*!BIT_initDStream
378 *  Initialize a BIT_DStream_t.
379 *  @bitD : a pointer to an already allocated BIT_DStream_t structure
380 *  @srcBuffer must point at the beginning of a bitStream
381 *  @srcSize must be the exact size of the bitStream
382 *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
383 */
384 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
385 {
386     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
387 
388     if (srcSize >=  sizeof(size_t))   /* normal case */
389     {
390         U32 contain32;
391         bitD->start = (const char*)srcBuffer;
392         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
393         bitD->bitContainer = MEM_readLEST(bitD->ptr);
394         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
395         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
396         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
397     }
398     else
399     {
400         U32 contain32;
401         bitD->start = (const char*)srcBuffer;
402         bitD->ptr   = bitD->start;
403         bitD->bitContainer = *(const BYTE*)(bitD->start);
404         switch(srcSize)
405         {
406             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
407                     /* fallthrough */
408             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
409                     /* fallthrough */
410             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
411                     /* fallthrough */
412             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
413                     /* fallthrough */
414             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
415                     /* fallthrough */
416             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
417                     /* fallthrough */
418             default:;
419         }
420         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
421         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
422         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
423         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
424     }
425 
426     return srcSize;
427 }
428 
429 MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
430 {
431     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
432     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
433 }
434 
435 /*! BIT_lookBitsFast :
436 *   unsafe version; only works only if nbBits >= 1 */
437 MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
438 {
439     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
440     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
441 }
442 
443 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
444 {
445     bitD->bitsConsumed += nbBits;
446 }
447 
448 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
449 {
450     size_t value = BIT_lookBits(bitD, nbBits);
451     BIT_skipBits(bitD, nbBits);
452     return value;
453 }
454 
455 /*!BIT_readBitsFast :
456 *  unsafe version; only works only if nbBits >= 1 */
457 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
458 {
459     size_t value = BIT_lookBitsFast(bitD, nbBits);
460     BIT_skipBits(bitD, nbBits);
461     return value;
462 }
463 
464 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
465 {
466     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
467         return BIT_DStream_overflow;
468 
469     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
470     {
471         bitD->ptr -= bitD->bitsConsumed >> 3;
472         bitD->bitsConsumed &= 7;
473         bitD->bitContainer = MEM_readLEST(bitD->ptr);
474         return BIT_DStream_unfinished;
475     }
476     if (bitD->ptr == bitD->start)
477     {
478         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
479         return BIT_DStream_completed;
480     }
481     {
482         U32 nbBytes = bitD->bitsConsumed >> 3;
483         BIT_DStream_status result = BIT_DStream_unfinished;
484         if (bitD->ptr - nbBytes < bitD->start)
485         {
486             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
487             result = BIT_DStream_endOfBuffer;
488         }
489         bitD->ptr -= nbBytes;
490         bitD->bitsConsumed -= nbBytes*8;
491         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
492         return result;
493     }
494 }
495 
496 /*! BIT_endOfDStream
497 *   @return Tells if DStream has reached its exact end
498 */
499 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
500 {
501     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
502 }
503 
504 #if defined (__cplusplus)
505 }
506 #endif
507 
508 #endif /* BITSTREAM_H_MODULE */
509 /* ******************************************************************
510    Error codes and messages
511    Copyright (C) 2013-2015, Yann Collet
512 
513    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
514 
515    Redistribution and use in source and binary forms, with or without
516    modification, are permitted provided that the following conditions are
517    met:
518 
519        * Redistributions of source code must retain the above copyright
520    notice, this list of conditions and the following disclaimer.
521        * Redistributions in binary form must reproduce the above
522    copyright notice, this list of conditions and the following disclaimer
523    in the documentation and/or other materials provided with the
524    distribution.
525 
526    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
527    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
528    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
529    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
530    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
531    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
532    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
533    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
534    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
535    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
536    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
537 
538    You can contact the author at :
539    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
540    - Public forum : https://groups.google.com/forum/#!forum/lz4c
541 ****************************************************************** */
542 #ifndef ERROR_H_MODULE
543 #define ERROR_H_MODULE
544 
545 #if defined (__cplusplus)
546 extern "C" {
547 #endif
548 
549 
550 /******************************************
551 *  Compiler-specific
552 ******************************************/
553 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
554 #  define ERR_STATIC static inline
555 #elif defined(_MSC_VER)
556 #  define ERR_STATIC static __inline
557 #elif defined(__GNUC__)
558 #  define ERR_STATIC static __attribute__((unused))
559 #else
560 #  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
561 #endif
562 
563 
564 /******************************************
565 *  Error Management
566 ******************************************/
567 #define PREFIX(name) ZSTD_error_##name
568 
569 #define ERROR(name) (size_t)-PREFIX(name)
570 
571 #define ERROR_LIST(ITEM) \
572         ITEM(PREFIX(No_Error)) ITEM(PREFIX(GENERIC)) \
573         ITEM(PREFIX(dstSize_tooSmall)) ITEM(PREFIX(srcSize_wrong)) \
574         ITEM(PREFIX(prefix_unknown)) ITEM(PREFIX(corruption_detected)) \
575         ITEM(PREFIX(tableLog_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooSmall)) \
576         ITEM(PREFIX(maxCode))
577 
578 #define ERROR_GENERATE_ENUM(ENUM) ENUM,
579 typedef enum { ERROR_LIST(ERROR_GENERATE_ENUM) } ERR_codes;  /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
580 
581 #define ERROR_CONVERTTOSTRING(STRING) #STRING,
582 #define ERROR_GENERATE_STRING(EXPR) ERROR_CONVERTTOSTRING(EXPR)
583 static const char* ERR_strings[] = { ERROR_LIST(ERROR_GENERATE_STRING) };
584 
585 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
586 
587 ERR_STATIC const char* ERR_getErrorName(size_t code)
588 {
589     static const char* codeError = "Unspecified error code";
590     if (ERR_isError(code)) return ERR_strings[-(int)(code)];
591     return codeError;
592 }
593 
594 
595 #if defined (__cplusplus)
596 }
597 #endif
598 
599 #endif /* ERROR_H_MODULE */
600 /*
601 Constructor and Destructor of type FSE_CTable
602     Note that its size depends on 'tableLog' and 'maxSymbolValue' */
603 typedef unsigned FSE_CTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
604 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
605 
606 
607 /* ******************************************************************
608    FSE : Finite State Entropy coder
609    header file for static linking (only)
610    Copyright (C) 2013-2015, Yann Collet
611 
612    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
613 
614    Redistribution and use in source and binary forms, with or without
615    modification, are permitted provided that the following conditions are
616    met:
617 
618        * Redistributions of source code must retain the above copyright
619    notice, this list of conditions and the following disclaimer.
620        * Redistributions in binary form must reproduce the above
621    copyright notice, this list of conditions and the following disclaimer
622    in the documentation and/or other materials provided with the
623    distribution.
624 
625    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
626    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
627    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
628    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
629    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
630    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
631    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
632    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
633    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
634    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
635    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
636 
637    You can contact the author at :
638    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
639    - Public forum : https://groups.google.com/forum/#!forum/lz4c
640 ****************************************************************** */
641 #if defined (__cplusplus)
642 extern "C" {
643 #endif
644 
645 
646 /******************************************
647 *  Static allocation
648 ******************************************/
649 /* FSE buffer bounds */
650 #define FSE_NCOUNTBOUND 512
651 #define FSE_BLOCKBOUND(size) (size + (size>>7))
652 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
653 
654 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
655 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
656 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<maxTableLog))
657 
658 
659 /******************************************
660 *  FSE advanced API
661 ******************************************/
662 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
663 /* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
664 
665 static size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
666 /* build a fake FSE_DTable, designed to always generate the same symbolValue */
667 
668 
669 /******************************************
670 *  FSE symbol decompression API
671 ******************************************/
672 typedef struct
673 {
674     size_t      state;
675     const void* table;   /* precise table may vary, depending on U16 */
676 } FSE_DState_t;
677 
678 
679 static void     FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
680 
681 static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
682 
683 static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
684 
685 
686 /******************************************
687 *  FSE unsafe API
688 ******************************************/
689 static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
690 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
691 
692 
693 /******************************************
694 *  Implementation of inline functions
695 ******************************************/
696 
697 /* decompression */
698 
699 typedef struct {
700     U16 tableLog;
701     U16 fastMode;
702 } FSE_DTableHeader;   /* sizeof U32 */
703 
704 typedef struct
705 {
706     unsigned short newState;
707     unsigned char  symbol;
708     unsigned char  nbBits;
709 } FSE_decode_t;   /* size == U32 */
710 
711 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
712 {
713     FSE_DTableHeader DTableH;
714     memcpy(&DTableH, dt, sizeof(DTableH));
715     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
716     BIT_reloadDStream(bitD);
717     DStatePtr->table = dt + 1;
718 }
719 
720 MEM_STATIC BYTE FSE_decodeSymbol(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_readBits(bitD, nbBits);
726 
727     DStatePtr->state = DInfo.newState + lowBits;
728     return symbol;
729 }
730 
731 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
732 {
733     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
734     const U32 nbBits = DInfo.nbBits;
735     BYTE symbol = DInfo.symbol;
736     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
737 
738     DStatePtr->state = DInfo.newState + lowBits;
739     return symbol;
740 }
741 
742 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
743 {
744     return DStatePtr->state == 0;
745 }
746 
747 
748 #if defined (__cplusplus)
749 }
750 #endif
751 /* ******************************************************************
752    Huff0 : Huffman coder, part of New Generation Entropy library
753    header file for static linking (only)
754    Copyright (C) 2013-2015, Yann Collet
755 
756    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
757 
758    Redistribution and use in source and binary forms, with or without
759    modification, are permitted provided that the following conditions are
760    met:
761 
762        * Redistributions of source code must retain the above copyright
763    notice, this list of conditions and the following disclaimer.
764        * Redistributions in binary form must reproduce the above
765    copyright notice, this list of conditions and the following disclaimer
766    in the documentation and/or other materials provided with the
767    distribution.
768 
769    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
770    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
771    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
772    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
773    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
774    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
775    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
776    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
777    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
778    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
779    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
780 
781    You can contact the author at :
782    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
783    - Public forum : https://groups.google.com/forum/#!forum/lz4c
784 ****************************************************************** */
785 
786 #if defined (__cplusplus)
787 extern "C" {
788 #endif
789 
790 /******************************************
791 *  Static allocation macros
792 ******************************************/
793 /* Huff0 buffer bounds */
794 #define HUF_CTABLEBOUND 129
795 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
796 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
797 
798 /* static allocation of Huff0's DTable */
799 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<maxTableLog))  /* nb Cells; use unsigned short for X2, unsigned int for X4 */
800 #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
801         unsigned short DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
802 #define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
803         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
804 #define HUF_CREATE_STATIC_DTABLEX6(DTable, maxTableLog) \
805         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog) * 3 / 2] = { maxTableLog }
806 
807 
808 /******************************************
809 *  Advanced functions
810 ******************************************/
811 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
812 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbols decoder */
813 static size_t HUF_decompress4X6 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* quad-symbols decoder */
814 
815 
816 #if defined (__cplusplus)
817 }
818 #endif
819 
820 /*
821     zstd - standard compression library
822     Header File
823     Copyright (C) 2014-2015, Yann Collet.
824 
825     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
826 
827     Redistribution and use in source and binary forms, with or without
828     modification, are permitted provided that the following conditions are
829     met:
830     * Redistributions of source code must retain the above copyright
831     notice, this list of conditions and the following disclaimer.
832     * Redistributions in binary form must reproduce the above
833     copyright notice, this list of conditions and the following disclaimer
834     in the documentation and/or other materials provided with the
835     distribution.
836     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
837     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
838     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
839     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
840     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
841     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
842     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
843     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
844     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
845     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
846     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
847 
848     You can contact the author at :
849     - zstd source repository : https://github.com/Cyan4973/zstd
850     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
851 */
852 
853 #if defined (__cplusplus)
854 extern "C" {
855 #endif
856 
857 /* *************************************
858 *  Includes
859 ***************************************/
860 #include <stddef.h>   /* size_t */
861 
862 
863 /* *************************************
864 *  Version
865 ***************************************/
866 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
867 #define ZSTD_VERSION_MINOR    2    /* for new (non-breaking) interface capabilities */
868 #define ZSTD_VERSION_RELEASE  2    /* for tweaks, bug-fixes, or development */
869 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
870 
871 
872 /* *************************************
873 *  Advanced functions
874 ***************************************/
875 typedef struct ZSTD_CCtx_s ZSTD_CCtx;   /* incomplete type */
876 
877 #if defined (__cplusplus)
878 }
879 #endif
880 /*
881     zstd - standard compression library
882     Header File for static linking only
883     Copyright (C) 2014-2015, Yann Collet.
884 
885     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
886 
887     Redistribution and use in source and binary forms, with or without
888     modification, are permitted provided that the following conditions are
889     met:
890     * Redistributions of source code must retain the above copyright
891     notice, this list of conditions and the following disclaimer.
892     * Redistributions in binary form must reproduce the above
893     copyright notice, this list of conditions and the following disclaimer
894     in the documentation and/or other materials provided with the
895     distribution.
896     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
897     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
898     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
899     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
900     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
901     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
902     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
903     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
904     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
905     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
906     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
907 
908     You can contact the author at :
909     - zstd source repository : https://github.com/Cyan4973/zstd
910     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
911 */
912 
913 /* The objects defined into this file should be considered experimental.
914  * They are not labelled stable, as their prototype may change in the future.
915  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
916  */
917 
918 #if defined (__cplusplus)
919 extern "C" {
920 #endif
921 
922 /* *************************************
923 *  Streaming functions
924 ***************************************/
925 
926 typedef struct ZSTD_DCtx_s ZSTD_DCtx;
927 
928 /*
929   Use above functions alternatively.
930   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
931   ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
932   Result is the number of bytes regenerated within 'dst'.
933   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
934 */
935 
936 /* *************************************
937 *  Prefix - version detection
938 ***************************************/
939 #define ZSTD_magicNumber 0xFD2FB522   /* v0.2 (current)*/
940 
941 
942 #if defined (__cplusplus)
943 }
944 #endif
945 /* ******************************************************************
946    FSE : Finite State Entropy coder
947    Copyright (C) 2013-2015, Yann Collet.
948 
949    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
950 
951    Redistribution and use in source and binary forms, with or without
952    modification, are permitted provided that the following conditions are
953    met:
954 
955        * Redistributions of source code must retain the above copyright
956    notice, this list of conditions and the following disclaimer.
957        * Redistributions in binary form must reproduce the above
958    copyright notice, this list of conditions and the following disclaimer
959    in the documentation and/or other materials provided with the
960    distribution.
961 
962    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
963    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
964    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
965    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
966    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
967    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
968    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
969    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
970    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
971    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
972    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
973 
974     You can contact the author at :
975     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
976     - Public forum : https://groups.google.com/forum/#!forum/lz4c
977 ****************************************************************** */
978 
979 #ifndef FSE_COMMONDEFS_ONLY
980 
981 /****************************************************************
982 *  Tuning parameters
983 ****************************************************************/
984 /* MEMORY_USAGE :
985 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
986 *  Increasing memory usage improves compression ratio
987 *  Reduced memory usage can improve speed, due to cache effect
988 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
989 #define FSE_MAX_MEMORY_USAGE 14
990 #define FSE_DEFAULT_MEMORY_USAGE 13
991 
992 /* FSE_MAX_SYMBOL_VALUE :
993 *  Maximum symbol value authorized.
994 *  Required for proper stack allocation */
995 #define FSE_MAX_SYMBOL_VALUE 255
996 
997 
998 /****************************************************************
999 *  template functions type & suffix
1000 ****************************************************************/
1001 #define FSE_FUNCTION_TYPE BYTE
1002 #define FSE_FUNCTION_EXTENSION
1003 
1004 
1005 /****************************************************************
1006 *  Byte symbol type
1007 ****************************************************************/
1008 #endif   /* !FSE_COMMONDEFS_ONLY */
1009 
1010 
1011 /****************************************************************
1012 *  Compiler specifics
1013 ****************************************************************/
1014 #ifdef _MSC_VER    /* Visual Studio */
1015 #  define FORCE_INLINE static __forceinline
1016 #  include <intrin.h>                    /* For Visual 2005 */
1017 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1018 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
1019 #else
1020 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
1021 #    ifdef __GNUC__
1022 #      define FORCE_INLINE static inline __attribute__((always_inline))
1023 #    else
1024 #      define FORCE_INLINE static inline
1025 #    endif
1026 #  else
1027 #    define FORCE_INLINE static
1028 #  endif /* __STDC_VERSION__ */
1029 #endif
1030 
1031 
1032 /****************************************************************
1033 *  Includes
1034 ****************************************************************/
1035 #include <stdlib.h>     /* malloc, free, qsort */
1036 #include <string.h>     /* memcpy, memset */
1037 #include <stdio.h>      /* printf (debug) */
1038 
1039 /****************************************************************
1040 *  Constants
1041 *****************************************************************/
1042 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
1043 #define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
1044 #define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
1045 #define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
1046 #define FSE_MIN_TABLELOG 5
1047 
1048 #define FSE_TABLELOG_ABSOLUTE_MAX 15
1049 #if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
1050 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
1051 #endif
1052 
1053 
1054 /****************************************************************
1055 *  Error Management
1056 ****************************************************************/
1057 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1058 
1059 
1060 /****************************************************************
1061 *  Complex types
1062 ****************************************************************/
1063 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
1064 
1065 
1066 /****************************************************************
1067 *  Templates
1068 ****************************************************************/
1069 /*
1070   designed to be included
1071   for type-specific functions (template emulation in C)
1072   Objective is to write these functions only once, for improved maintenance
1073 */
1074 
1075 /* safety checks */
1076 #ifndef FSE_FUNCTION_EXTENSION
1077 #  error "FSE_FUNCTION_EXTENSION must be defined"
1078 #endif
1079 #ifndef FSE_FUNCTION_TYPE
1080 #  error "FSE_FUNCTION_TYPE must be defined"
1081 #endif
1082 
1083 /* Function names */
1084 #define FSE_CAT(X,Y) X##Y
1085 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
1086 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
1087 
1088 
1089 /* Function templates */
1090 
1091 #define FSE_DECODE_TYPE FSE_decode_t
1092 
1093 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
1094 
1095 static size_t FSE_buildDTable
1096 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
1097 {
1098     void* ptr = dt+1;
1099     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)ptr;
1100     FSE_DTableHeader DTableH;
1101     const U32 tableSize = 1 << tableLog;
1102     const U32 tableMask = tableSize-1;
1103     const U32 step = FSE_tableStep(tableSize);
1104     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
1105     U32 position = 0;
1106     U32 highThreshold = tableSize-1;
1107     const S16 largeLimit= (S16)(1 << (tableLog-1));
1108     U32 noLarge = 1;
1109     U32 s;
1110 
1111     /* Sanity Checks */
1112     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
1113     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
1114 
1115     /* Init, lay down lowprob symbols */
1116     DTableH.tableLog = (U16)tableLog;
1117     for (s=0; s<=maxSymbolValue; s++)
1118     {
1119         if (normalizedCounter[s]==-1)
1120         {
1121             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
1122             symbolNext[s] = 1;
1123         }
1124         else
1125         {
1126             if (normalizedCounter[s] >= largeLimit) noLarge=0;
1127             symbolNext[s] = normalizedCounter[s];
1128         }
1129     }
1130 
1131     /* Spread symbols */
1132     for (s=0; s<=maxSymbolValue; s++)
1133     {
1134         int i;
1135         for (i=0; i<normalizedCounter[s]; i++)
1136         {
1137             tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
1138             position = (position + step) & tableMask;
1139             while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
1140         }
1141     }
1142 
1143     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
1144 
1145     /* Build Decoding table */
1146     {
1147         U32 i;
1148         for (i=0; i<tableSize; i++)
1149         {
1150             FSE_FUNCTION_TYPE symbol = (FSE_FUNCTION_TYPE)(tableDecode[i].symbol);
1151             U16 nextState = symbolNext[symbol]++;
1152             tableDecode[i].nbBits = (BYTE) (tableLog - BIT_highbit32 ((U32)nextState) );
1153             tableDecode[i].newState = (U16) ( (nextState << tableDecode[i].nbBits) - tableSize);
1154         }
1155     }
1156 
1157     DTableH.fastMode = (U16)noLarge;
1158     memcpy(dt, &DTableH, sizeof(DTableH));   /* memcpy(), to avoid strict aliasing warnings */
1159     return 0;
1160 }
1161 
1162 
1163 #ifndef FSE_COMMONDEFS_ONLY
1164 /******************************************
1165 *  FSE helper functions
1166 ******************************************/
1167 static unsigned FSE_isError(size_t code) { return ERR_isError(code); }
1168 
1169 
1170 /****************************************************************
1171 *  FSE NCount encoding-decoding
1172 ****************************************************************/
1173 static short FSE_abs(short a)
1174 {
1175     return (short)(a<0 ? -a : a);
1176 }
1177 
1178 static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
1179                  const void* headerBuffer, size_t hbSize)
1180 {
1181     const BYTE* const istart = (const BYTE*) headerBuffer;
1182     const BYTE* const iend = istart + hbSize;
1183     const BYTE* ip = istart;
1184     int nbBits;
1185     int remaining;
1186     int threshold;
1187     U32 bitStream;
1188     int bitCount;
1189     unsigned charnum = 0;
1190     int previous0 = 0;
1191 
1192     if (hbSize < 4) return ERROR(srcSize_wrong);
1193     bitStream = MEM_readLE32(ip);
1194     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
1195     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
1196     bitStream >>= 4;
1197     bitCount = 4;
1198     *tableLogPtr = nbBits;
1199     remaining = (1<<nbBits)+1;
1200     threshold = 1<<nbBits;
1201     nbBits++;
1202 
1203     while ((remaining>1) && (charnum<=*maxSVPtr))
1204     {
1205         if (previous0)
1206         {
1207             unsigned n0 = charnum;
1208             while ((bitStream & 0xFFFF) == 0xFFFF)
1209             {
1210                 n0+=24;
1211                 if (ip < iend-5)
1212                 {
1213                     ip+=2;
1214                     bitStream = MEM_readLE32(ip) >> bitCount;
1215                 }
1216                 else
1217                 {
1218                     bitStream >>= 16;
1219                     bitCount+=16;
1220                 }
1221             }
1222             while ((bitStream & 3) == 3)
1223             {
1224                 n0+=3;
1225                 bitStream>>=2;
1226                 bitCount+=2;
1227             }
1228             n0 += bitStream & 3;
1229             bitCount += 2;
1230             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
1231             while (charnum < n0) normalizedCounter[charnum++] = 0;
1232             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1233             {
1234                 ip += bitCount>>3;
1235                 bitCount &= 7;
1236                 bitStream = MEM_readLE32(ip) >> bitCount;
1237             }
1238             else
1239                 bitStream >>= 2;
1240         }
1241         {
1242             const short max = (short)((2*threshold-1)-remaining);
1243             short count;
1244 
1245             if ((bitStream & (threshold-1)) < (U32)max)
1246             {
1247                 count = (short)(bitStream & (threshold-1));
1248                 bitCount   += nbBits-1;
1249             }
1250             else
1251             {
1252                 count = (short)(bitStream & (2*threshold-1));
1253                 if (count >= threshold) count -= max;
1254                 bitCount   += nbBits;
1255             }
1256 
1257             count--;   /* extra accuracy */
1258             remaining -= FSE_abs(count);
1259             normalizedCounter[charnum++] = count;
1260             previous0 = !count;
1261             while (remaining < threshold)
1262             {
1263                 nbBits--;
1264                 threshold >>= 1;
1265             }
1266 
1267             {
1268                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1269                 {
1270                     ip += bitCount>>3;
1271                     bitCount &= 7;
1272                 }
1273                 else
1274                 {
1275                     bitCount -= (int)(8 * (iend - 4 - ip));
1276                     ip = iend - 4;
1277                 }
1278                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
1279             }
1280         }
1281     }
1282     if (remaining != 1) return ERROR(GENERIC);
1283     *maxSVPtr = charnum-1;
1284 
1285     ip += (bitCount+7)>>3;
1286     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
1287     return ip-istart;
1288 }
1289 
1290 
1291 /*********************************************************
1292 *  Decompression (Byte symbols)
1293 *********************************************************/
1294 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
1295 {
1296     void* ptr = dt;
1297     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1298     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
1299 
1300     DTableH->tableLog = 0;
1301     DTableH->fastMode = 0;
1302 
1303     cell->newState = 0;
1304     cell->symbol = symbolValue;
1305     cell->nbBits = 0;
1306 
1307     return 0;
1308 }
1309 
1310 
1311 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
1312 {
1313     void* ptr = dt;
1314     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1315     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
1316     const unsigned tableSize = 1 << nbBits;
1317     const unsigned tableMask = tableSize - 1;
1318     const unsigned maxSymbolValue = tableMask;
1319     unsigned s;
1320 
1321     /* Sanity checks */
1322     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
1323 
1324     /* Build Decoding Table */
1325     DTableH->tableLog = (U16)nbBits;
1326     DTableH->fastMode = 1;
1327     for (s=0; s<=maxSymbolValue; s++)
1328     {
1329         dinfo[s].newState = 0;
1330         dinfo[s].symbol = (BYTE)s;
1331         dinfo[s].nbBits = (BYTE)nbBits;
1332     }
1333 
1334     return 0;
1335 }
1336 
1337 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
1338           void* dst, size_t maxDstSize,
1339     const void* cSrc, size_t cSrcSize,
1340     const FSE_DTable* dt, const unsigned fast)
1341 {
1342     BYTE* const ostart = (BYTE*) dst;
1343     BYTE* op = ostart;
1344     BYTE* const omax = op + maxDstSize;
1345     BYTE* const olimit = omax-3;
1346 
1347     BIT_DStream_t bitD;
1348     FSE_DState_t state1;
1349     FSE_DState_t state2;
1350     size_t errorCode;
1351 
1352     /* Init */
1353     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
1354     if (FSE_isError(errorCode)) return errorCode;
1355 
1356     FSE_initDState(&state1, &bitD, dt);
1357     FSE_initDState(&state2, &bitD, dt);
1358 
1359 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
1360 
1361     /* 4 symbols per loop */
1362     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op<olimit) ; op+=4)
1363     {
1364         op[0] = FSE_GETSYMBOL(&state1);
1365 
1366         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1367             BIT_reloadDStream(&bitD);
1368 
1369         op[1] = FSE_GETSYMBOL(&state2);
1370 
1371         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1372             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
1373 
1374         op[2] = FSE_GETSYMBOL(&state1);
1375 
1376         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1377             BIT_reloadDStream(&bitD);
1378 
1379         op[3] = FSE_GETSYMBOL(&state2);
1380     }
1381 
1382     /* tail */
1383     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
1384     while (1)
1385     {
1386         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
1387             break;
1388 
1389         *op++ = FSE_GETSYMBOL(&state1);
1390 
1391         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
1392             break;
1393 
1394         *op++ = FSE_GETSYMBOL(&state2);
1395     }
1396 
1397     /* end ? */
1398     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
1399         return op-ostart;
1400 
1401     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
1402 
1403     return ERROR(corruption_detected);
1404 }
1405 
1406 
1407 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
1408                             const void* cSrc, size_t cSrcSize,
1409                             const FSE_DTable* dt)
1410 {
1411     FSE_DTableHeader DTableH;
1412     memcpy(&DTableH, dt, sizeof(DTableH));
1413 
1414     /* select fast mode (static) */
1415     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
1416     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
1417 }
1418 
1419 
1420 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
1421 {
1422     const BYTE* const istart = (const BYTE*)cSrc;
1423     const BYTE* ip = istart;
1424     short counting[FSE_MAX_SYMBOL_VALUE+1];
1425     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
1426     unsigned tableLog;
1427     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
1428     size_t errorCode;
1429 
1430     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
1431 
1432     /* normal FSE decoding mode */
1433     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
1434     if (FSE_isError(errorCode)) return errorCode;
1435     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
1436     ip += errorCode;
1437     cSrcSize -= errorCode;
1438 
1439     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
1440     if (FSE_isError(errorCode)) return errorCode;
1441 
1442     /* always return, even if it is an error code */
1443     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
1444 }
1445 
1446 
1447 
1448 #endif   /* FSE_COMMONDEFS_ONLY */
1449 /* ******************************************************************
1450    Huff0 : Huffman coder, part of New Generation Entropy library
1451    Copyright (C) 2013-2015, Yann Collet.
1452 
1453    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1454 
1455    Redistribution and use in source and binary forms, with or without
1456    modification, are permitted provided that the following conditions are
1457    met:
1458 
1459        * Redistributions of source code must retain the above copyright
1460    notice, this list of conditions and the following disclaimer.
1461        * Redistributions in binary form must reproduce the above
1462    copyright notice, this list of conditions and the following disclaimer
1463    in the documentation and/or other materials provided with the
1464    distribution.
1465 
1466    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1467    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1468    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1469    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1470    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1471    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1472    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1473    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1474    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1475    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1476    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1477 
1478     You can contact the author at :
1479     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
1480     - Public forum : https://groups.google.com/forum/#!forum/lz4c
1481 ****************************************************************** */
1482 
1483 /****************************************************************
1484 *  Compiler specifics
1485 ****************************************************************/
1486 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
1487 /* inline is defined */
1488 #elif defined(_MSC_VER)
1489 #  define inline __inline
1490 #else
1491 #  define inline /* disable inline */
1492 #endif
1493 
1494 
1495 #ifdef _MSC_VER    /* Visual Studio */
1496 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1497 #endif
1498 
1499 
1500 /****************************************************************
1501 *  Includes
1502 ****************************************************************/
1503 #include <stdlib.h>     /* malloc, free, qsort */
1504 #include <string.h>     /* memcpy, memset */
1505 #include <stdio.h>      /* printf (debug) */
1506 
1507 /****************************************************************
1508 *  Error Management
1509 ****************************************************************/
1510 #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1511 
1512 
1513 /******************************************
1514 *  Helper functions
1515 ******************************************/
1516 static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
1517 
1518 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
1519 #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
1520 #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
1521 #define HUF_MAX_SYMBOL_VALUE 255
1522 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
1523 #  error "HUF_MAX_TABLELOG is too large !"
1524 #endif
1525 
1526 
1527 
1528 /*********************************************************
1529 *  Huff0 : Huffman block decompression
1530 *********************************************************/
1531 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
1532 
1533 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
1534 
1535 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
1536 
1537 /*! HUF_readStats
1538     Read compact Huffman tree, saved by HUF_writeCTable
1539     @huffWeight : destination buffer
1540     @return : size read from `src`
1541 */
1542 static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
1543                             U32* nbSymbolsPtr, U32* tableLogPtr,
1544                             const void* src, size_t srcSize)
1545 {
1546     U32 weightTotal;
1547     U32 tableLog;
1548     const BYTE* ip = (const BYTE*) src;
1549     size_t iSize;
1550     size_t oSize;
1551     U32 n;
1552 
1553     if (!srcSize) return ERROR(srcSize_wrong);
1554     iSize = ip[0];
1555     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
1556 
1557     if (iSize >= 128)  /* special header */
1558     {
1559         if (iSize >= (242))   /* RLE */
1560         {
1561             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
1562             oSize = l[iSize-242];
1563             memset(huffWeight, 1, hwSize);
1564             iSize = 0;
1565         }
1566         else   /* Incompressible */
1567         {
1568             oSize = iSize - 127;
1569             iSize = ((oSize+1)/2);
1570             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1571             if (oSize >= hwSize) return ERROR(corruption_detected);
1572             ip += 1;
1573             for (n=0; n<oSize; n+=2)
1574             {
1575                 huffWeight[n]   = ip[n/2] >> 4;
1576                 huffWeight[n+1] = ip[n/2] & 15;
1577             }
1578         }
1579     }
1580     else  /* header compressed with FSE (normal case) */
1581     {
1582         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1583         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
1584         if (FSE_isError(oSize)) return oSize;
1585     }
1586 
1587     /* collect weight stats */
1588     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
1589     weightTotal = 0;
1590     for (n=0; n<oSize; n++)
1591     {
1592         if (huffWeight[n] >= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1593         rankStats[huffWeight[n]]++;
1594         weightTotal += (1 << huffWeight[n]) >> 1;
1595     }
1596     if (weightTotal == 0) return ERROR(corruption_detected);
1597 
1598     /* get last non-null symbol weight (implied, total must be 2^n) */
1599     tableLog = BIT_highbit32(weightTotal) + 1;
1600     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1601     {
1602         U32 total = 1 << tableLog;
1603         U32 rest = total - weightTotal;
1604         U32 verif = 1 << BIT_highbit32(rest);
1605         U32 lastWeight = BIT_highbit32(rest) + 1;
1606         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
1607         huffWeight[oSize] = (BYTE)lastWeight;
1608         rankStats[lastWeight]++;
1609     }
1610 
1611     /* check tree construction validity */
1612     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
1613 
1614     /* results */
1615     *nbSymbolsPtr = (U32)(oSize+1);
1616     *tableLogPtr = tableLog;
1617     return iSize+1;
1618 }
1619 
1620 
1621 /**************************/
1622 /* single-symbol decoding */
1623 /**************************/
1624 
1625 static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
1626 {
1627     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
1628     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
1629     U32 tableLog = 0;
1630     const BYTE* ip = (const BYTE*) src;
1631     size_t iSize = ip[0];
1632     U32 nbSymbols = 0;
1633     U32 n;
1634     U32 nextRankStart;
1635     void* ptr = DTable+1;
1636     HUF_DEltX2* const dt = (HUF_DEltX2*)ptr;
1637 
1638     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
1639     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
1640 
1641     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
1642     if (HUF_isError(iSize)) return iSize;
1643 
1644     /* check result */
1645     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
1646     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
1647 
1648     /* Prepare ranks */
1649     nextRankStart = 0;
1650     for (n=1; n<=tableLog; n++)
1651     {
1652         U32 current = nextRankStart;
1653         nextRankStart += (rankVal[n] << (n-1));
1654         rankVal[n] = current;
1655     }
1656 
1657     /* fill DTable */
1658     for (n=0; n<nbSymbols; n++)
1659     {
1660         const U32 w = huffWeight[n];
1661         const U32 length = (1 << w) >> 1;
1662         U32 i;
1663         HUF_DEltX2 D;
1664         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
1665         for (i = rankVal[w]; i < rankVal[w] + length; i++)
1666             dt[i] = D;
1667         rankVal[w] += length;
1668     }
1669 
1670     return iSize;
1671 }
1672 
1673 static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
1674 {
1675         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
1676         const BYTE c = dt[val].byte;
1677         BIT_skipBits(Dstream, dt[val].nbBits);
1678         return c;
1679 }
1680 
1681 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
1682     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
1683 
1684 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
1685     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
1686         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1687 
1688 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
1689     if (MEM_64bits()) \
1690         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1691 
1692 static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
1693 {
1694     BYTE* const pStart = p;
1695 
1696     /* up to 4 symbols at a time */
1697     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
1698     {
1699         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1700         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
1701         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1702         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1703     }
1704 
1705     /* closer to the end */
1706     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
1707         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1708 
1709     /* no more data to retrieve from bitstream, hence no need to reload */
1710     while (p < pEnd)
1711         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1712 
1713     return pEnd-pStart;
1714 }
1715 
1716 
1717 static size_t HUF_decompress4X2_usingDTable(
1718           void* dst,  size_t dstSize,
1719     const void* cSrc, size_t cSrcSize,
1720     const U16* DTable)
1721 {
1722     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
1723 
1724     {
1725         const BYTE* const istart = (const BYTE*) cSrc;
1726         BYTE* const ostart = (BYTE*) dst;
1727         BYTE* const oend = ostart + dstSize;
1728 
1729         const void* ptr = DTable;
1730         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)ptr) +1;
1731         const U32 dtLog = DTable[0];
1732         size_t errorCode;
1733 
1734         /* Init */
1735         BIT_DStream_t bitD1;
1736         BIT_DStream_t bitD2;
1737         BIT_DStream_t bitD3;
1738         BIT_DStream_t bitD4;
1739         const size_t length1 = MEM_readLE16(istart);
1740         const size_t length2 = MEM_readLE16(istart+2);
1741         const size_t length3 = MEM_readLE16(istart+4);
1742         size_t length4;
1743         const BYTE* const istart1 = istart + 6;  /* jumpTable */
1744         const BYTE* const istart2 = istart1 + length1;
1745         const BYTE* const istart3 = istart2 + length2;
1746         const BYTE* const istart4 = istart3 + length3;
1747         const size_t segmentSize = (dstSize+3) / 4;
1748         BYTE* const opStart2 = ostart + segmentSize;
1749         BYTE* const opStart3 = opStart2 + segmentSize;
1750         BYTE* const opStart4 = opStart3 + segmentSize;
1751         BYTE* op1 = ostart;
1752         BYTE* op2 = opStart2;
1753         BYTE* op3 = opStart3;
1754         BYTE* op4 = opStart4;
1755         U32 endSignal;
1756 
1757         length4 = cSrcSize - (length1 + length2 + length3 + 6);
1758         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
1759         errorCode = BIT_initDStream(&bitD1, istart1, length1);
1760         if (HUF_isError(errorCode)) return errorCode;
1761         errorCode = BIT_initDStream(&bitD2, istart2, length2);
1762         if (HUF_isError(errorCode)) return errorCode;
1763         errorCode = BIT_initDStream(&bitD3, istart3, length3);
1764         if (HUF_isError(errorCode)) return errorCode;
1765         errorCode = BIT_initDStream(&bitD4, istart4, length4);
1766         if (HUF_isError(errorCode)) return errorCode;
1767 
1768         /* 16-32 symbols per loop (4-8 symbols per stream) */
1769         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1770         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
1771         {
1772             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1773             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1774             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1775             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1776             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
1777             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
1778             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
1779             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
1780             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1781             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1782             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1783             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1784             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
1785             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
1786             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
1787             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
1788 
1789             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1790         }
1791 
1792         /* check corruption */
1793         if (op1 > opStart2) return ERROR(corruption_detected);
1794         if (op2 > opStart3) return ERROR(corruption_detected);
1795         if (op3 > opStart4) return ERROR(corruption_detected);
1796         /* note : op4 supposed already verified within main loop */
1797 
1798         /* finish bitStreams one by one */
1799         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
1800         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
1801         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
1802         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
1803 
1804         /* check */
1805         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
1806         if (!endSignal) return ERROR(corruption_detected);
1807 
1808         /* decoded size */
1809         return dstSize;
1810     }
1811 }
1812 
1813 
1814 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
1815 {
1816     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
1817     const BYTE* ip = (const BYTE*) cSrc;
1818     size_t errorCode;
1819 
1820     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
1821     if (HUF_isError(errorCode)) return errorCode;
1822     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
1823     ip += errorCode;
1824     cSrcSize -= errorCode;
1825 
1826     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
1827 }
1828 
1829 
1830 /***************************/
1831 /* double-symbols decoding */
1832 /***************************/
1833 
1834 static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
1835                            const U32* rankValOrigin, const int minWeight,
1836                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
1837                            U32 nbBitsBaseline, U16 baseSeq)
1838 {
1839     HUF_DEltX4 DElt;
1840     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1841     U32 s;
1842 
1843     /* get pre-calculated rankVal */
1844     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1845 
1846     /* fill skipped values */
1847     if (minWeight>1)
1848     {
1849         U32 i, skipSize = rankVal[minWeight];
1850         MEM_writeLE16(&(DElt.sequence), baseSeq);
1851         DElt.nbBits   = (BYTE)(consumed);
1852         DElt.length   = 1;
1853         for (i = 0; i < skipSize; i++)
1854             DTable[i] = DElt;
1855     }
1856 
1857     /* fill DTable */
1858     for (s=0; s<sortedListSize; s++)   /* note : sortedSymbols already skipped */
1859     {
1860         const U32 symbol = sortedSymbols[s].symbol;
1861         const U32 weight = sortedSymbols[s].weight;
1862         const U32 nbBits = nbBitsBaseline - weight;
1863         const U32 length = 1 << (sizeLog-nbBits);
1864         const U32 start = rankVal[weight];
1865         U32 i = start;
1866         const U32 end = start + length;
1867 
1868         MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
1869         DElt.nbBits = (BYTE)(nbBits + consumed);
1870         DElt.length = 2;
1871         do { DTable[i++] = DElt; } while (i<end);   /* since length >= 1 */
1872 
1873         rankVal[weight] += length;
1874     }
1875 }
1876 
1877 typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
1878 
1879 static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
1880                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
1881                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
1882                            const U32 nbBitsBaseline)
1883 {
1884     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1885     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
1886     const U32 minBits  = nbBitsBaseline - maxWeight;
1887     U32 s;
1888 
1889     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1890 
1891     /* fill DTable */
1892     for (s=0; s<sortedListSize; s++)
1893     {
1894         const U16 symbol = sortedList[s].symbol;
1895         const U32 weight = sortedList[s].weight;
1896         const U32 nbBits = nbBitsBaseline - weight;
1897         const U32 start = rankVal[weight];
1898         const U32 length = 1 << (targetLog-nbBits);
1899 
1900         if (targetLog-nbBits >= minBits)   /* enough room for a second symbol */
1901         {
1902             U32 sortedRank;
1903             int minWeight = nbBits + scaleLog;
1904             if (minWeight < 1) minWeight = 1;
1905             sortedRank = rankStart[minWeight];
1906             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
1907                            rankValOrigin[nbBits], minWeight,
1908                            sortedList+sortedRank, sortedListSize-sortedRank,
1909                            nbBitsBaseline, symbol);
1910         }
1911         else
1912         {
1913             U32 i;
1914             const U32 end = start + length;
1915             HUF_DEltX4 DElt;
1916 
1917             MEM_writeLE16(&(DElt.sequence), symbol);
1918             DElt.nbBits   = (BYTE)(nbBits);
1919             DElt.length   = 1;
1920             for (i = start; i < end; i++)
1921                 DTable[i] = DElt;
1922         }
1923         rankVal[weight] += length;
1924     }
1925 }
1926 
1927 static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
1928 {
1929     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
1930     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
1931     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
1932     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
1933     U32* const rankStart = rankStart0+1;
1934     rankVal_t rankVal;
1935     U32 tableLog, maxW, sizeOfSort, nbSymbols;
1936     const U32 memLog = DTable[0];
1937     const BYTE* ip = (const BYTE*) src;
1938     size_t iSize = ip[0];
1939     void* ptr = DTable;
1940     HUF_DEltX4* const dt = ((HUF_DEltX4*)ptr) + 1;
1941 
1942     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
1943     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
1944     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
1945 
1946     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
1947     if (HUF_isError(iSize)) return iSize;
1948 
1949     /* check result */
1950     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
1951 
1952     /* find maxWeight */
1953     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
1954         {if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
1955 
1956     /* Get start index of each weight */
1957     {
1958         U32 w, nextRankStart = 0;
1959         for (w=1; w<=maxW; w++)
1960         {
1961             U32 current = nextRankStart;
1962             nextRankStart += rankStats[w];
1963             rankStart[w] = current;
1964         }
1965         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
1966         sizeOfSort = nextRankStart;
1967     }
1968 
1969     /* sort symbols by weight */
1970     {
1971         U32 s;
1972         for (s=0; s<nbSymbols; s++)
1973         {
1974             U32 w = weightList[s];
1975             U32 r = rankStart[w]++;
1976             sortedSymbol[r].symbol = (BYTE)s;
1977             sortedSymbol[r].weight = (BYTE)w;
1978         }
1979         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
1980     }
1981 
1982     /* Build rankVal */
1983     {
1984         const U32 minBits = tableLog+1 - maxW;
1985         U32 nextRankVal = 0;
1986         U32 w, consumed;
1987         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
1988         U32* rankVal0 = rankVal[0];
1989         for (w=1; w<=maxW; w++)
1990         {
1991             U32 current = nextRankVal;
1992             nextRankVal += rankStats[w] << (w+rescale);
1993             rankVal0[w] = current;
1994         }
1995         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
1996         {
1997             U32* rankValPtr = rankVal[consumed];
1998             for (w = 1; w <= maxW; w++)
1999             {
2000                 rankValPtr[w] = rankVal0[w] >> consumed;
2001             }
2002         }
2003     }
2004 
2005     HUF_fillDTableX4(dt, memLog,
2006                    sortedSymbol, sizeOfSort,
2007                    rankStart0, rankVal, maxW,
2008                    tableLog+1);
2009 
2010     return iSize;
2011 }
2012 
2013 
2014 static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2015 {
2016     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2017     memcpy(op, dt+val, 2);
2018     BIT_skipBits(DStream, dt[val].nbBits);
2019     return dt[val].length;
2020 }
2021 
2022 static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2023 {
2024     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2025     memcpy(op, dt+val, 1);
2026     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
2027     else
2028     {
2029         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
2030         {
2031             BIT_skipBits(DStream, dt[val].nbBits);
2032             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2033                 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 */
2034         }
2035     }
2036     return 1;
2037 }
2038 
2039 
2040 #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
2041     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2042 
2043 #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
2044     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
2045         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2046 
2047 #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
2048     if (MEM_64bits()) \
2049         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2050 
2051 static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
2052 {
2053     BYTE* const pStart = p;
2054 
2055     /* up to 8 symbols at a time */
2056     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
2057     {
2058         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2059         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
2060         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2061         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2062     }
2063 
2064     /* closer to the end */
2065     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
2066         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2067 
2068     while (p <= pEnd-2)
2069         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2070 
2071     if (p < pEnd)
2072         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
2073 
2074     return p-pStart;
2075 }
2076 
2077 
2078 
2079 static size_t HUF_decompress4X4_usingDTable(
2080           void* dst,  size_t dstSize,
2081     const void* cSrc, size_t cSrcSize,
2082     const U32* DTable)
2083 {
2084     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2085 
2086     {
2087         const BYTE* const istart = (const BYTE*) cSrc;
2088         BYTE* const ostart = (BYTE*) dst;
2089         BYTE* const oend = ostart + dstSize;
2090 
2091         const void* ptr = DTable;
2092         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)ptr) +1;
2093         const U32 dtLog = DTable[0];
2094         size_t errorCode;
2095 
2096         /* Init */
2097         BIT_DStream_t bitD1;
2098         BIT_DStream_t bitD2;
2099         BIT_DStream_t bitD3;
2100         BIT_DStream_t bitD4;
2101         const size_t length1 = MEM_readLE16(istart);
2102         const size_t length2 = MEM_readLE16(istart+2);
2103         const size_t length3 = MEM_readLE16(istart+4);
2104         size_t length4;
2105         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2106         const BYTE* const istart2 = istart1 + length1;
2107         const BYTE* const istart3 = istart2 + length2;
2108         const BYTE* const istart4 = istart3 + length3;
2109         const size_t segmentSize = (dstSize+3) / 4;
2110         BYTE* const opStart2 = ostart + segmentSize;
2111         BYTE* const opStart3 = opStart2 + segmentSize;
2112         BYTE* const opStart4 = opStart3 + segmentSize;
2113         BYTE* op1 = ostart;
2114         BYTE* op2 = opStart2;
2115         BYTE* op3 = opStart3;
2116         BYTE* op4 = opStart4;
2117         U32 endSignal;
2118 
2119         length4 = cSrcSize - (length1 + length2 + length3 + 6);
2120         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2121         errorCode = BIT_initDStream(&bitD1, istart1, length1);
2122         if (HUF_isError(errorCode)) return errorCode;
2123         errorCode = BIT_initDStream(&bitD2, istart2, length2);
2124         if (HUF_isError(errorCode)) return errorCode;
2125         errorCode = BIT_initDStream(&bitD3, istart3, length3);
2126         if (HUF_isError(errorCode)) return errorCode;
2127         errorCode = BIT_initDStream(&bitD4, istart4, length4);
2128         if (HUF_isError(errorCode)) return errorCode;
2129 
2130         /* 16-32 symbols per loop (4-8 symbols per stream) */
2131         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2132         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
2133         {
2134             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2135             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2136             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2137             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2138             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
2139             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
2140             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
2141             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
2142             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2143             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2144             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2145             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2146             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
2147             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
2148             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
2149             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
2150 
2151             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2152         }
2153 
2154         /* check corruption */
2155         if (op1 > opStart2) return ERROR(corruption_detected);
2156         if (op2 > opStart3) return ERROR(corruption_detected);
2157         if (op3 > opStart4) return ERROR(corruption_detected);
2158         /* note : op4 supposed already verified within main loop */
2159 
2160         /* finish bitStreams one by one */
2161         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
2162         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
2163         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
2164         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
2165 
2166         /* check */
2167         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
2168         if (!endSignal) return ERROR(corruption_detected);
2169 
2170         /* decoded size */
2171         return dstSize;
2172     }
2173 }
2174 
2175 
2176 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2177 {
2178     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
2179     const BYTE* ip = (const BYTE*) cSrc;
2180 
2181     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
2182     if (HUF_isError(hSize)) return hSize;
2183     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2184     ip += hSize;
2185     cSrcSize -= hSize;
2186 
2187     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
2188 }
2189 
2190 
2191 /**********************************/
2192 /* quad-symbol decoding           */
2193 /**********************************/
2194 typedef struct { BYTE nbBits; BYTE nbBytes; } HUF_DDescX6;
2195 typedef union { BYTE byte[4]; U32 sequence; } HUF_DSeqX6;
2196 
2197 /* recursive, up to level 3; may benefit from <template>-like strategy to nest each level inline */
2198 static void HUF_fillDTableX6LevelN(HUF_DDescX6* DDescription, HUF_DSeqX6* DSequence, int sizeLog,
2199                            const rankVal_t rankValOrigin, const U32 consumed, const int minWeight, const U32 maxWeight,
2200                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize, const U32* rankStart,
2201                            const U32 nbBitsBaseline, HUF_DSeqX6 baseSeq, HUF_DDescX6 DDesc)
2202 {
2203     const int scaleLog = nbBitsBaseline - sizeLog;   /* note : targetLog >= (nbBitsBaseline-1), hence scaleLog <= 1 */
2204     const int minBits  = nbBitsBaseline - maxWeight;
2205     const U32 level = DDesc.nbBytes;
2206     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
2207     U32 symbolStartPos, s;
2208 
2209     /* local rankVal, will be modified */
2210     memcpy(rankVal, rankValOrigin[consumed], sizeof(rankVal));
2211 
2212     /* fill skipped values */
2213     if (minWeight>1)
2214     {
2215         U32 i;
2216         const U32 skipSize = rankVal[minWeight];
2217         for (i = 0; i < skipSize; i++)
2218         {
2219             DSequence[i] = baseSeq;
2220             DDescription[i] = DDesc;
2221         }
2222     }
2223 
2224     /* fill DTable */
2225     DDesc.nbBytes++;
2226     symbolStartPos = rankStart[minWeight];
2227     for (s=symbolStartPos; s<sortedListSize; s++)
2228     {
2229         const BYTE symbol = sortedSymbols[s].symbol;
2230         const U32  weight = sortedSymbols[s].weight;   /* >= 1 (sorted) */
2231         const int  nbBits = nbBitsBaseline - weight;   /* >= 1 (by construction) */
2232         const int  totalBits = consumed+nbBits;
2233         const U32  start  = rankVal[weight];
2234         const U32  length = 1 << (sizeLog-nbBits);
2235         baseSeq.byte[level] = symbol;
2236         DDesc.nbBits = (BYTE)totalBits;
2237 
2238         if ((level<3) && (sizeLog-totalBits >= minBits))   /* enough room for another symbol */
2239         {
2240             int nextMinWeight = totalBits + scaleLog;
2241             if (nextMinWeight < 1) nextMinWeight = 1;
2242             HUF_fillDTableX6LevelN(DDescription+start, DSequence+start, sizeLog-nbBits,
2243                            rankValOrigin, totalBits, nextMinWeight, maxWeight,
2244                            sortedSymbols, sortedListSize, rankStart,
2245                            nbBitsBaseline, baseSeq, DDesc);   /* recursive (max : level 3) */
2246         }
2247         else
2248         {
2249             U32 i;
2250             const U32 end = start + length;
2251             for (i = start; i < end; i++)
2252             {
2253                 DDescription[i] = DDesc;
2254                 DSequence[i] = baseSeq;
2255             }
2256         }
2257         rankVal[weight] += length;
2258     }
2259 }
2260 
2261 
2262 /* note : same preparation as X4 */
2263 static size_t HUF_readDTableX6 (U32* DTable, const void* src, size_t srcSize)
2264 {
2265     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
2266     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
2267     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
2268     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
2269     U32* const rankStart = rankStart0+1;
2270     U32 tableLog, maxW, sizeOfSort, nbSymbols;
2271     rankVal_t rankVal;
2272     const U32 memLog = DTable[0];
2273     const BYTE* ip = (const BYTE*) src;
2274     size_t iSize = ip[0];
2275 
2276     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
2277     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
2278 
2279     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
2280     if (HUF_isError(iSize)) return iSize;
2281 
2282     /* check result */
2283     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable is too small */
2284 
2285     /* find maxWeight */
2286     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
2287         { if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
2288 
2289 
2290     /* Get start index of each weight */
2291     {
2292         U32 w, nextRankStart = 0;
2293         for (w=1; w<=maxW; w++)
2294         {
2295             U32 current = nextRankStart;
2296             nextRankStart += rankStats[w];
2297             rankStart[w] = current;
2298         }
2299         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
2300         sizeOfSort = nextRankStart;
2301     }
2302 
2303     /* sort symbols by weight */
2304     {
2305         U32 s;
2306         for (s=0; s<nbSymbols; s++)
2307         {
2308             U32 w = weightList[s];
2309             U32 r = rankStart[w]++;
2310             sortedSymbol[r].symbol = (BYTE)s;
2311             sortedSymbol[r].weight = (BYTE)w;
2312         }
2313         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
2314     }
2315 
2316     /* Build rankVal */
2317     {
2318         const U32 minBits = tableLog+1 - maxW;
2319         U32 nextRankVal = 0;
2320         U32 w, consumed;
2321         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
2322         U32* rankVal0 = rankVal[0];
2323         for (w=1; w<=maxW; w++)
2324         {
2325             U32 current = nextRankVal;
2326             nextRankVal += rankStats[w] << (w+rescale);
2327             rankVal0[w] = current;
2328         }
2329         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
2330         {
2331             U32* rankValPtr = rankVal[consumed];
2332             for (w = 1; w <= maxW; w++)
2333             {
2334                 rankValPtr[w] = rankVal0[w] >> consumed;
2335             }
2336         }
2337     }
2338 
2339 
2340     /* fill tables */
2341     {
2342         void* ptr = DTable+1;
2343         HUF_DDescX6* DDescription = (HUF_DDescX6*)(ptr);
2344         void* dSeqStart = DTable + 1 + ((size_t)1<<(memLog-1));
2345         HUF_DSeqX6* DSequence = (HUF_DSeqX6*)(dSeqStart);
2346         HUF_DSeqX6 DSeq;
2347         HUF_DDescX6 DDesc;
2348         DSeq.sequence = 0;
2349         DDesc.nbBits = 0;
2350         DDesc.nbBytes = 0;
2351         HUF_fillDTableX6LevelN(DDescription, DSequence, memLog,
2352                        (const U32 (*)[HUF_ABSOLUTEMAX_TABLELOG + 1])rankVal, 0, 1, maxW,
2353                        sortedSymbol, sizeOfSort, rankStart0,
2354                        tableLog+1, DSeq, DDesc);
2355     }
2356 
2357     return iSize;
2358 }
2359 
2360 
2361 static U32 HUF_decodeSymbolX6(void* op, BIT_DStream_t* DStream, const HUF_DDescX6* dd, const HUF_DSeqX6* ds, const U32 dtLog)
2362 {
2363     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2364     memcpy(op, ds+val, sizeof(HUF_DSeqX6));
2365     BIT_skipBits(DStream, dd[val].nbBits);
2366     return dd[val].nbBytes;
2367 }
2368 
2369 static U32 HUF_decodeLastSymbolsX6(void* op, const U32 maxL, BIT_DStream_t* DStream,
2370                                   const HUF_DDescX6* dd, const HUF_DSeqX6* ds, const U32 dtLog)
2371 {
2372     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2373     U32 length = dd[val].nbBytes;
2374     if (length <= maxL)
2375     {
2376         memcpy(op, ds+val, length);
2377         BIT_skipBits(DStream, dd[val].nbBits);
2378         return length;
2379     }
2380     memcpy(op, ds+val, maxL);
2381     if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
2382     {
2383         BIT_skipBits(DStream, dd[val].nbBits);
2384         if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2385             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 */
2386     }
2387     return maxL;
2388 }
2389 
2390 
2391 #define HUF_DECODE_SYMBOLX6_0(ptr, DStreamPtr) \
2392     ptr += HUF_decodeSymbolX6(ptr, DStreamPtr, dd, ds, dtLog)
2393 
2394 #define HUF_DECODE_SYMBOLX6_1(ptr, DStreamPtr) \
2395     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
2396         HUF_DECODE_SYMBOLX6_0(ptr, DStreamPtr)
2397 
2398 #define HUF_DECODE_SYMBOLX6_2(ptr, DStreamPtr) \
2399     if (MEM_64bits()) \
2400         HUF_DECODE_SYMBOLX6_0(ptr, DStreamPtr)
2401 
2402 static inline size_t HUF_decodeStreamX6(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const U32* DTable, const U32 dtLog)
2403 {
2404     const void* ddPtr = DTable+1;
2405     const HUF_DDescX6* dd = (const HUF_DDescX6*)(ddPtr);
2406     const void* dsPtr = DTable + 1 + ((size_t)1<<(dtLog-1));
2407     const HUF_DSeqX6* ds = (const HUF_DSeqX6*)(dsPtr);
2408     BYTE* const pStart = p;
2409 
2410     /* up to 16 symbols at a time */
2411     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-16))
2412     {
2413         HUF_DECODE_SYMBOLX6_2(p, bitDPtr);
2414         HUF_DECODE_SYMBOLX6_1(p, bitDPtr);
2415         HUF_DECODE_SYMBOLX6_2(p, bitDPtr);
2416         HUF_DECODE_SYMBOLX6_0(p, bitDPtr);
2417     }
2418 
2419     /* closer to the end, up to 4 symbols at a time */
2420     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
2421         HUF_DECODE_SYMBOLX6_0(p, bitDPtr);
2422 
2423     while (p <= pEnd-4)
2424         HUF_DECODE_SYMBOLX6_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2425 
2426     while (p < pEnd)
2427         p += HUF_decodeLastSymbolsX6(p, (U32)(pEnd-p), bitDPtr, dd, ds, dtLog);
2428 
2429     return p-pStart;
2430 }
2431 
2432 
2433 
2434 static size_t HUF_decompress4X6_usingDTable(
2435           void* dst,  size_t dstSize,
2436     const void* cSrc, size_t cSrcSize,
2437     const U32* DTable)
2438 {
2439     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2440 
2441     {
2442         const BYTE* const istart = (const BYTE*) cSrc;
2443         BYTE* const ostart = (BYTE*) dst;
2444         BYTE* const oend = ostart + dstSize;
2445 
2446         const U32 dtLog = DTable[0];
2447         const void* ddPtr = DTable+1;
2448         const HUF_DDescX6* dd = (const HUF_DDescX6*)(ddPtr);
2449         const void* dsPtr = DTable + 1 + ((size_t)1<<(dtLog-1));
2450         const HUF_DSeqX6* ds = (const HUF_DSeqX6*)(dsPtr);
2451         size_t errorCode;
2452 
2453         /* Init */
2454         BIT_DStream_t bitD1;
2455         BIT_DStream_t bitD2;
2456         BIT_DStream_t bitD3;
2457         BIT_DStream_t bitD4;
2458         const size_t length1 = MEM_readLE16(istart);
2459         const size_t length2 = MEM_readLE16(istart+2);
2460         const size_t length3 = MEM_readLE16(istart+4);
2461         size_t length4;
2462         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2463         const BYTE* const istart2 = istart1 + length1;
2464         const BYTE* const istart3 = istart2 + length2;
2465         const BYTE* const istart4 = istart3 + length3;
2466         const size_t segmentSize = (dstSize+3) / 4;
2467         BYTE* const opStart2 = ostart + segmentSize;
2468         BYTE* const opStart3 = opStart2 + segmentSize;
2469         BYTE* const opStart4 = opStart3 + segmentSize;
2470         BYTE* op1 = ostart;
2471         BYTE* op2 = opStart2;
2472         BYTE* op3 = opStart3;
2473         BYTE* op4 = opStart4;
2474         U32 endSignal;
2475 
2476         length4 = cSrcSize - (length1 + length2 + length3 + 6);
2477         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2478         errorCode = BIT_initDStream(&bitD1, istart1, length1);
2479         if (HUF_isError(errorCode)) return errorCode;
2480         errorCode = BIT_initDStream(&bitD2, istart2, length2);
2481         if (HUF_isError(errorCode)) return errorCode;
2482         errorCode = BIT_initDStream(&bitD3, istart3, length3);
2483         if (HUF_isError(errorCode)) return errorCode;
2484         errorCode = BIT_initDStream(&bitD4, istart4, length4);
2485         if (HUF_isError(errorCode)) return errorCode;
2486 
2487         /* 16-64 symbols per loop (4-16 symbols per stream) */
2488         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2489         for ( ; (op3 <= opStart4) && (endSignal==BIT_DStream_unfinished) && (op4<=(oend-16)) ; )
2490         {
2491             HUF_DECODE_SYMBOLX6_2(op1, &bitD1);
2492             HUF_DECODE_SYMBOLX6_2(op2, &bitD2);
2493             HUF_DECODE_SYMBOLX6_2(op3, &bitD3);
2494             HUF_DECODE_SYMBOLX6_2(op4, &bitD4);
2495             HUF_DECODE_SYMBOLX6_1(op1, &bitD1);
2496             HUF_DECODE_SYMBOLX6_1(op2, &bitD2);
2497             HUF_DECODE_SYMBOLX6_1(op3, &bitD3);
2498             HUF_DECODE_SYMBOLX6_1(op4, &bitD4);
2499             HUF_DECODE_SYMBOLX6_2(op1, &bitD1);
2500             HUF_DECODE_SYMBOLX6_2(op2, &bitD2);
2501             HUF_DECODE_SYMBOLX6_2(op3, &bitD3);
2502             HUF_DECODE_SYMBOLX6_2(op4, &bitD4);
2503             HUF_DECODE_SYMBOLX6_0(op1, &bitD1);
2504             HUF_DECODE_SYMBOLX6_0(op2, &bitD2);
2505             HUF_DECODE_SYMBOLX6_0(op3, &bitD3);
2506             HUF_DECODE_SYMBOLX6_0(op4, &bitD4);
2507 
2508             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2509         }
2510 
2511         /* check corruption */
2512         if (op1 > opStart2) return ERROR(corruption_detected);
2513         if (op2 > opStart3) return ERROR(corruption_detected);
2514         if (op3 > opStart4) return ERROR(corruption_detected);
2515         /* note : op4 supposed already verified within main loop */
2516 
2517         /* finish bitStreams one by one */
2518         HUF_decodeStreamX6(op1, &bitD1, opStart2, DTable, dtLog);
2519         HUF_decodeStreamX6(op2, &bitD2, opStart3, DTable, dtLog);
2520         HUF_decodeStreamX6(op3, &bitD3, opStart4, DTable, dtLog);
2521         HUF_decodeStreamX6(op4, &bitD4, oend,     DTable, dtLog);
2522 
2523         /* check */
2524         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
2525         if (!endSignal) return ERROR(corruption_detected);
2526 
2527         /* decoded size */
2528         return dstSize;
2529     }
2530 }
2531 
2532 
2533 static size_t HUF_decompress4X6 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2534 {
2535     HUF_CREATE_STATIC_DTABLEX6(DTable, HUF_MAX_TABLELOG);
2536     const BYTE* ip = (const BYTE*) cSrc;
2537 
2538     size_t hSize = HUF_readDTableX6 (DTable, cSrc, cSrcSize);
2539     if (HUF_isError(hSize)) return hSize;
2540     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2541     ip += hSize;
2542     cSrcSize -= hSize;
2543 
2544     return HUF_decompress4X6_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
2545 }
2546 
2547 
2548 /**********************************/
2549 /* Generic decompression selector */
2550 /**********************************/
2551 
2552 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
2553 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
2554 {
2555     /* single, double, quad */
2556     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
2557     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
2558     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
2559     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
2560     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
2561     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
2562     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
2563     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
2564     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
2565     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
2566     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
2567     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
2568     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
2569     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
2570     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
2571     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
2572 };
2573 
2574 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
2575 
2576 static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2577 {
2578     static const decompressionAlgo decompress[3] = { HUF_decompress4X2, HUF_decompress4X4, HUF_decompress4X6 };
2579     /* estimate decompression time */
2580     U32 Q;
2581     const U32 D256 = (U32)(dstSize >> 8);
2582     U32 Dtime[3];
2583     U32 algoNb = 0;
2584     int n;
2585 
2586     /* validation checks */
2587     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2588     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2589     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2590     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2591 
2592     /* decoder timing evaluation */
2593     Q = (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 since dstSize > cSrcSize */
2594     for (n=0; n<3; n++)
2595         Dtime[n] = algoTime[Q][n].tableTime + (algoTime[Q][n].decode256Time * D256);
2596 
2597     Dtime[1] += Dtime[1] >> 4; Dtime[2] += Dtime[2] >> 3; /* advantage to algorithms using less memory, for cache eviction */
2598 
2599     if (Dtime[1] < Dtime[0]) algoNb = 1;
2600     if (Dtime[2] < Dtime[algoNb]) algoNb = 2;
2601 
2602     return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
2603 
2604     //return HUF_decompress4X2(dst, dstSize, cSrc, cSrcSize);   /* multi-streams single-symbol decoding */
2605     //return HUF_decompress4X4(dst, dstSize, cSrc, cSrcSize);   /* multi-streams double-symbols decoding */
2606     //return HUF_decompress4X6(dst, dstSize, cSrc, cSrcSize);   /* multi-streams quad-symbols decoding */
2607 }
2608 /*
2609     zstd - standard compression library
2610     Copyright (C) 2014-2015, Yann Collet.
2611 
2612     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2613 
2614     Redistribution and use in source and binary forms, with or without
2615     modification, are permitted provided that the following conditions are
2616     met:
2617     * Redistributions of source code must retain the above copyright
2618     notice, this list of conditions and the following disclaimer.
2619     * Redistributions in binary form must reproduce the above
2620     copyright notice, this list of conditions and the following disclaimer
2621     in the documentation and/or other materials provided with the
2622     distribution.
2623     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2624     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2625     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2626     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2627     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2628     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2629     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2630     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2631     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2632     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2633     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2634 
2635     You can contact the author at :
2636     - zstd source repository : https://github.com/Cyan4973/zstd
2637     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
2638 */
2639 
2640 /* ***************************************************************
2641 *  Tuning parameters
2642 *****************************************************************/
2643 /*!
2644 *  MEMORY_USAGE :
2645 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
2646 *  Increasing memory usage improves compression ratio
2647 *  Reduced memory usage can improve speed, due to cache effect
2648 */
2649 #define ZSTD_MEMORY_USAGE 17
2650 
2651 /*!
2652  * HEAPMODE :
2653  * Select how default compression functions will allocate memory for their hash table,
2654  * in memory stack (0, fastest), or in memory heap (1, requires malloc())
2655  * Note that compression context is fairly large, as a consequence heap memory is recommended.
2656  */
2657 #ifndef ZSTD_HEAPMODE
2658 #  define ZSTD_HEAPMODE 1
2659 #endif /* ZSTD_HEAPMODE */
2660 
2661 /*!
2662 *  LEGACY_SUPPORT :
2663 *  decompressor can decode older formats (starting from Zstd 0.1+)
2664 */
2665 #ifndef ZSTD_LEGACY_SUPPORT
2666 #  define ZSTD_LEGACY_SUPPORT 1
2667 #endif
2668 
2669 
2670 /* *******************************************************
2671 *  Includes
2672 *********************************************************/
2673 #include <stdlib.h>      /* calloc */
2674 #include <string.h>      /* memcpy, memmove */
2675 #include <stdio.h>       /* debug : printf */
2676 
2677 
2678 /* *******************************************************
2679 *  Compiler specifics
2680 *********************************************************/
2681 #ifdef __AVX2__
2682 #  include <immintrin.h>   /* AVX2 intrinsics */
2683 #endif
2684 
2685 #ifdef _MSC_VER    /* Visual Studio */
2686 #  include <intrin.h>                    /* For Visual 2005 */
2687 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
2688 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
2689 #endif
2690 
2691 
2692 /* *******************************************************
2693 *  Constants
2694 *********************************************************/
2695 #define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
2696 #define HASH_TABLESIZE (1 << HASH_LOG)
2697 #define HASH_MASK (HASH_TABLESIZE - 1)
2698 
2699 #define KNUTH 2654435761
2700 
2701 #define BIT7 128
2702 #define BIT6  64
2703 #define BIT5  32
2704 #define BIT4  16
2705 #define BIT1   2
2706 #define BIT0   1
2707 
2708 #define KB *(1 <<10)
2709 #define MB *(1 <<20)
2710 #define GB *(1U<<30)
2711 
2712 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
2713 #define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
2714 #define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
2715 #define IS_RAW BIT0
2716 #define IS_RLE BIT1
2717 
2718 #define WORKPLACESIZE (BLOCKSIZE*3)
2719 #define MINMATCH 4
2720 #define MLbits   7
2721 #define LLbits   6
2722 #define Offbits  5
2723 #define MaxML  ((1<<MLbits )-1)
2724 #define MaxLL  ((1<<LLbits )-1)
2725 #define MaxOff   31
2726 #define LitFSELog  11
2727 #define MLFSELog   10
2728 #define LLFSELog   10
2729 #define OffFSELog   9
2730 #define MAX(a,b) ((a)<(b)?(b):(a))
2731 #define MaxSeq MAX(MaxLL, MaxML)
2732 
2733 #define LITERAL_NOENTROPY 63
2734 #define COMMAND_NOENTROPY 7   /* to remove */
2735 
2736 #define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
2737 
2738 static const size_t ZSTD_blockHeaderSize = 3;
2739 static const size_t ZSTD_frameHeaderSize = 4;
2740 
2741 
2742 /* *******************************************************
2743 *  Memory operations
2744 **********************************************************/
2745 static void   ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
2746 
2747 static void   ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
2748 
2749 #define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }
2750 
2751 /*! ZSTD_wildcopy : custom version of memcpy(), can copy up to 7-8 bytes too many */
2752 static void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length)
2753 {
2754     const BYTE* ip = (const BYTE*)src;
2755     BYTE* op = (BYTE*)dst;
2756     BYTE* const oend = op + length;
2757     do COPY8(op, ip) while (op < oend);
2758 }
2759 
2760 
2761 /* **************************************
2762 *  Local structures
2763 ****************************************/
2764 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
2765 
2766 typedef struct
2767 {
2768     blockType_t blockType;
2769     U32 origSize;
2770 } blockProperties_t;
2771 
2772 typedef struct {
2773     void* buffer;
2774     U32*  offsetStart;
2775     U32*  offset;
2776     BYTE* offCodeStart;
2777     BYTE* offCode;
2778     BYTE* litStart;
2779     BYTE* lit;
2780     BYTE* litLengthStart;
2781     BYTE* litLength;
2782     BYTE* matchLengthStart;
2783     BYTE* matchLength;
2784     BYTE* dumpsStart;
2785     BYTE* dumps;
2786 } seqStore_t;
2787 
2788 
2789 /* *************************************
2790 *  Error Management
2791 ***************************************/
2792 /*! ZSTD_isError
2793 *   tells if a return value is an error code */
2794 static unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
2795 
2796 
2797 
2798 /* *************************************************************
2799 *   Decompression section
2800 ***************************************************************/
2801 struct ZSTD_DCtx_s
2802 {
2803     U32 LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
2804     U32 OffTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
2805     U32 MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
2806     void* previousDstEnd;
2807     void* base;
2808     size_t expected;
2809     blockType_t bType;
2810     U32 phase;
2811     const BYTE* litPtr;
2812     size_t litSize;
2813     BYTE litBuffer[BLOCKSIZE + 8 /* margin for wildcopy */];
2814 };   /* typedef'd to ZSTD_Dctx within "zstd_static.h" */
2815 
2816 
2817 static size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
2818 {
2819     const BYTE* const in = (const BYTE* const)src;
2820     BYTE headerFlags;
2821     U32 cSize;
2822 
2823     if (srcSize < 3) return ERROR(srcSize_wrong);
2824 
2825     headerFlags = *in;
2826     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
2827 
2828     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
2829     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
2830 
2831     if (bpPtr->blockType == bt_end) return 0;
2832     if (bpPtr->blockType == bt_rle) return 1;
2833     return cSize;
2834 }
2835 
2836 static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
2837 {
2838     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
2839     if (srcSize > 0) {
2840         memcpy(dst, src, srcSize);
2841     }
2842     return srcSize;
2843 }
2844 
2845 
2846 /** ZSTD_decompressLiterals
2847     @return : nb of bytes read from src, or an error code*/
2848 static size_t ZSTD_decompressLiterals(void* dst, size_t* maxDstSizePtr,
2849                                 const void* src, size_t srcSize)
2850 {
2851     const BYTE* ip = (const BYTE*)src;
2852 
2853     const size_t litSize = (MEM_readLE32(src) & 0x1FFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2854     const size_t litCSize = (MEM_readLE32(ip+2) & 0xFFFFFF) >> 5;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2855 
2856     if (litSize > *maxDstSizePtr) return ERROR(corruption_detected);
2857     if (litCSize + 5 > srcSize) return ERROR(corruption_detected);
2858 
2859     if (HUF_isError(HUF_decompress(dst, litSize, ip+5, litCSize))) return ERROR(corruption_detected);
2860 
2861     *maxDstSizePtr = litSize;
2862     return litCSize + 5;
2863 }
2864 
2865 
2866 /** ZSTD_decodeLiteralsBlock
2867     @return : nb of bytes read from src (< srcSize )*/
2868 static size_t ZSTD_decodeLiteralsBlock(void* ctx,
2869                           const void* src, size_t srcSize)
2870 {
2871     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
2872     const BYTE* const istart = (const BYTE* const)src;
2873 
2874     /* any compressed block with literals segment must be at least this size */
2875     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
2876 
2877     switch(*istart & 3)
2878     {
2879     default:
2880     case 0:
2881         {
2882             size_t litSize = BLOCKSIZE;
2883             const size_t readSize = ZSTD_decompressLiterals(dctx->litBuffer, &litSize, src, srcSize);
2884             dctx->litPtr = dctx->litBuffer;
2885             dctx->litSize = litSize;
2886             memset(dctx->litBuffer + dctx->litSize, 0, 8);
2887             return readSize;   /* works if it's an error too */
2888         }
2889     case IS_RAW:
2890         {
2891             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2892             if (litSize > srcSize-11)   /* risk of reading too far with wildcopy */
2893             {
2894                 if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2895                 if (litSize > srcSize-3) return ERROR(corruption_detected);
2896                 memcpy(dctx->litBuffer, istart, litSize);
2897                 dctx->litPtr = dctx->litBuffer;
2898                 dctx->litSize = litSize;
2899                 memset(dctx->litBuffer + dctx->litSize, 0, 8);
2900                 return litSize+3;
2901             }
2902             /* direct reference into compressed stream */
2903             dctx->litPtr = istart+3;
2904             dctx->litSize = litSize;
2905             return litSize+3;
2906         }
2907     case IS_RLE:
2908         {
2909             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2910             if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2911             memset(dctx->litBuffer, istart[3], litSize + 8);
2912             dctx->litPtr = dctx->litBuffer;
2913             dctx->litSize = litSize;
2914             return 4;
2915         }
2916     }
2917 }
2918 
2919 
2920 static size_t ZSTD_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
2921                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
2922                          const void* src, size_t srcSize)
2923 {
2924     const BYTE* const istart = (const BYTE* const)src;
2925     const BYTE* ip = istart;
2926     const BYTE* const iend = istart + srcSize;
2927     U32 LLtype, Offtype, MLtype;
2928     U32 LLlog, Offlog, MLlog;
2929     size_t dumpsLength;
2930 
2931     /* check */
2932     if (srcSize < 5) return ERROR(srcSize_wrong);
2933 
2934     /* SeqHead */
2935     *nbSeq = MEM_readLE16(ip); ip+=2;
2936     LLtype  = *ip >> 6;
2937     Offtype = (*ip >> 4) & 3;
2938     MLtype  = (*ip >> 2) & 3;
2939     if (*ip & 2)
2940     {
2941         dumpsLength  = ip[2];
2942         dumpsLength += ip[1] << 8;
2943         ip += 3;
2944     }
2945     else
2946     {
2947         dumpsLength  = ip[1];
2948         dumpsLength += (ip[0] & 1) << 8;
2949         ip += 2;
2950     }
2951     *dumpsPtr = ip;
2952     ip += dumpsLength;
2953     *dumpsLengthPtr = dumpsLength;
2954 
2955     /* check */
2956     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
2957 
2958     /* sequences */
2959     {
2960         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL and MaxOff */
2961         size_t headerSize;
2962 
2963         /* Build DTables */
2964         switch(LLtype)
2965         {
2966         case bt_rle :
2967             LLlog = 0;
2968             FSE_buildDTable_rle(DTableLL, *ip++); break;
2969         case bt_raw :
2970             LLlog = LLbits;
2971             FSE_buildDTable_raw(DTableLL, LLbits); break;
2972         default :
2973             {   U32 max = MaxLL;
2974                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
2975                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2976                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
2977                 ip += headerSize;
2978                 FSE_buildDTable(DTableLL, norm, max, LLlog);
2979         }   }
2980 
2981         switch(Offtype)
2982         {
2983         case bt_rle :
2984             Offlog = 0;
2985             if (ip > iend-2) return ERROR(srcSize_wrong);   /* min : "raw", hence no header, but at least xxLog bits */
2986             FSE_buildDTable_rle(DTableOffb, *ip++ & MaxOff); /* if *ip > MaxOff, data is corrupted */
2987             break;
2988         case bt_raw :
2989             Offlog = Offbits;
2990             FSE_buildDTable_raw(DTableOffb, Offbits); break;
2991         default :
2992             {   U32 max = MaxOff;
2993                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
2994                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2995                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
2996                 ip += headerSize;
2997                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
2998         }   }
2999 
3000         switch(MLtype)
3001         {
3002         case bt_rle :
3003             MLlog = 0;
3004             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
3005             FSE_buildDTable_rle(DTableML, *ip++); break;
3006         case bt_raw :
3007             MLlog = MLbits;
3008             FSE_buildDTable_raw(DTableML, MLbits); break;
3009         default :
3010             {   U32 max = MaxML;
3011                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
3012                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
3013                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
3014                 ip += headerSize;
3015                 FSE_buildDTable(DTableML, norm, max, MLlog);
3016     }   }   }
3017 
3018     return ip-istart;
3019 }
3020 
3021 
3022 typedef struct {
3023     size_t litLength;
3024     size_t offset;
3025     size_t matchLength;
3026 } seq_t;
3027 
3028 typedef struct {
3029     BIT_DStream_t DStream;
3030     FSE_DState_t stateLL;
3031     FSE_DState_t stateOffb;
3032     FSE_DState_t stateML;
3033     size_t prevOffset;
3034     const BYTE* dumps;
3035     const BYTE* dumpsEnd;
3036 } seqState_t;
3037 
3038 
3039 static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
3040 {
3041     size_t litLength;
3042     size_t prevOffset;
3043     size_t offset;
3044     size_t matchLength;
3045     const BYTE* dumps = seqState->dumps;
3046     const BYTE* const de = seqState->dumpsEnd;
3047 
3048     /* Literal length */
3049     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
3050     prevOffset = litLength ? seq->offset : seqState->prevOffset;
3051     seqState->prevOffset = seq->offset;
3052     if (litLength == MaxLL)
3053     {
3054         const U32 add = dumps<de ? *dumps++ : 0;
3055         if (add < 255) litLength += add;
3056         else if (dumps + 3 <= de)
3057         {
3058             litLength = MEM_readLE24(dumps);
3059             dumps += 3;
3060         }
3061         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
3062     }
3063 
3064     /* Offset */
3065     {
3066         static const size_t offsetPrefix[MaxOff+1] = {  /* note : size_t faster than U32 */
3067                 1 /*fake*/, 1, 2, 4, 8, 16, 32, 64, 128, 256,
3068                 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144,
3069                 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, /*fake*/ 1, 1, 1, 1, 1 };
3070         U32 offsetCode, nbBits;
3071         offsetCode = FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream));   /* <= maxOff, by table construction */
3072         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
3073         nbBits = offsetCode - 1;
3074         if (offsetCode==0) nbBits = 0;   /* cmove */
3075         offset = offsetPrefix[offsetCode] + BIT_readBits(&(seqState->DStream), nbBits);
3076         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
3077         if (offsetCode==0) offset = prevOffset;   /* cmove */
3078     }
3079 
3080     /* MatchLength */
3081     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
3082     if (matchLength == MaxML)
3083     {
3084         const U32 add = dumps<de ? *dumps++ : 0;
3085         if (add < 255) matchLength += add;
3086         else if (dumps + 3 <= de)
3087         {
3088             matchLength = MEM_readLE24(dumps);
3089             dumps += 3;
3090         }
3091         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
3092     }
3093     matchLength += MINMATCH;
3094 
3095     /* save result */
3096     seq->litLength = litLength;
3097     seq->offset = offset;
3098     seq->matchLength = matchLength;
3099     seqState->dumps = dumps;
3100 }
3101 
3102 
3103 static size_t ZSTD_execSequence(BYTE* op,
3104                                 seq_t sequence,
3105                                 const BYTE** litPtr, const BYTE* const litLimit,
3106                                 BYTE* const base, BYTE* const oend)
3107 {
3108     static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
3109     static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11};   /* subtracted */
3110     const BYTE* const ostart = op;
3111     BYTE* const oLitEnd = op + sequence.litLength;
3112     BYTE* const oMatchEnd = op + sequence.litLength + sequence.matchLength;   /* risk : address space overflow (32-bits) */
3113     BYTE* const oend_8 = oend-8;
3114     const BYTE* const litEnd = *litPtr + sequence.litLength;
3115 
3116     /* checks */
3117     if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall);   /* last match must start at a minimum distance of 8 from oend */
3118     if (oMatchEnd > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
3119     if (litEnd > litLimit) return ERROR(corruption_detected);   /* overRead beyond lit buffer */
3120 
3121     /* copy Literals */
3122     ZSTD_wildcopy(op, *litPtr, sequence.litLength);   /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
3123     op = oLitEnd;
3124     *litPtr = litEnd;   /* update for next sequence */
3125 
3126     /* copy Match */
3127     {
3128         const BYTE* match = op - sequence.offset;
3129 
3130         /* check */
3131         if (sequence.offset > (size_t)op) return ERROR(corruption_detected);   /* address space overflow test (this test seems kept by clang optimizer) */
3132         //if (match > op) return ERROR(corruption_detected);   /* address space overflow test (is clang optimizer removing this test ?) */
3133         if (match < base) return ERROR(corruption_detected);
3134 
3135         /* close range match, overlap */
3136         if (sequence.offset < 8)
3137         {
3138             const int dec64 = dec64table[sequence.offset];
3139             op[0] = match[0];
3140             op[1] = match[1];
3141             op[2] = match[2];
3142             op[3] = match[3];
3143             match += dec32table[sequence.offset];
3144             ZSTD_copy4(op+4, match);
3145             match -= dec64;
3146         }
3147         else
3148         {
3149             ZSTD_copy8(op, match);
3150         }
3151         op += 8; match += 8;
3152 
3153         if (oMatchEnd > oend-(16-MINMATCH))
3154         {
3155             if (op < oend_8)
3156             {
3157                 ZSTD_wildcopy(op, match, oend_8 - op);
3158                 match += oend_8 - op;
3159                 op = oend_8;
3160             }
3161             while (op < oMatchEnd) *op++ = *match++;
3162         }
3163         else
3164         {
3165             ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
3166         }
3167     }
3168 
3169     return oMatchEnd - ostart;
3170 }
3171 
3172 static size_t ZSTD_decompressSequences(
3173                                void* ctx,
3174                                void* dst, size_t maxDstSize,
3175                          const void* seqStart, size_t seqSize)
3176 {
3177     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
3178     const BYTE* ip = (const BYTE*)seqStart;
3179     const BYTE* const iend = ip + seqSize;
3180     BYTE* const ostart = (BYTE* const)dst;
3181     BYTE* op = ostart;
3182     BYTE* const oend = ostart + maxDstSize;
3183     size_t errorCode, dumpsLength;
3184     const BYTE* litPtr = dctx->litPtr;
3185     const BYTE* const litEnd = litPtr + dctx->litSize;
3186     int nbSeq;
3187     const BYTE* dumps;
3188     U32* DTableLL = dctx->LLTable;
3189     U32* DTableML = dctx->MLTable;
3190     U32* DTableOffb = dctx->OffTable;
3191     BYTE* const base = (BYTE*) (dctx->base);
3192 
3193     /* Build Decoding Tables */
3194     errorCode = ZSTD_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
3195                                       DTableLL, DTableML, DTableOffb,
3196                                       ip, iend-ip);
3197     if (ZSTD_isError(errorCode)) return errorCode;
3198     ip += errorCode;
3199 
3200     /* Regen sequences */
3201     {
3202         seq_t sequence;
3203         seqState_t seqState;
3204 
3205         memset(&sequence, 0, sizeof(sequence));
3206         seqState.dumps = dumps;
3207         seqState.dumpsEnd = dumps + dumpsLength;
3208         seqState.prevOffset = 1;
3209         errorCode = BIT_initDStream(&(seqState.DStream), ip, iend-ip);
3210         if (ERR_isError(errorCode)) return ERROR(corruption_detected);
3211         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
3212         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
3213         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
3214 
3215         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (nbSeq>0) ; )
3216         {
3217             size_t oneSeqSize;
3218             nbSeq--;
3219             ZSTD_decodeSequence(&sequence, &seqState);
3220             oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend);
3221             if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
3222             op += oneSeqSize;
3223         }
3224 
3225         /* check if reached exact end */
3226         if ( !BIT_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* requested too much : data is corrupted */
3227         if (nbSeq<0) return ERROR(corruption_detected);   /* requested too many sequences : data is corrupted */
3228 
3229         /* last literal segment */
3230         {
3231             size_t lastLLSize = litEnd - litPtr;
3232             if (litPtr > litEnd) return ERROR(corruption_detected);
3233             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
3234             if (lastLLSize > 0) {
3235                 if (op != litPtr) memmove(op, litPtr, lastLLSize);
3236                 op += lastLLSize;
3237             }
3238         }
3239     }
3240 
3241     return op-ostart;
3242 }
3243 
3244 
3245 static size_t ZSTD_decompressBlock(
3246                             void* ctx,
3247                             void* dst, size_t maxDstSize,
3248                       const void* src, size_t srcSize)
3249 {
3250     /* blockType == blockCompressed */
3251     const BYTE* ip = (const BYTE*)src;
3252 
3253     /* Decode literals sub-block */
3254     size_t litCSize = ZSTD_decodeLiteralsBlock(ctx, src, srcSize);
3255     if (ZSTD_isError(litCSize)) return litCSize;
3256     ip += litCSize;
3257     srcSize -= litCSize;
3258 
3259     return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize);
3260 }
3261 
3262 
3263 static size_t ZSTD_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3264 {
3265     const BYTE* ip = (const BYTE*)src;
3266     const BYTE* iend = ip + srcSize;
3267     BYTE* const ostart = (BYTE* const)dst;
3268     BYTE* op = ostart;
3269     BYTE* const oend = ostart + maxDstSize;
3270     size_t remainingSize = srcSize;
3271     U32 magicNumber;
3272     blockProperties_t blockProperties;
3273 
3274     /* Frame Header */
3275     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
3276     magicNumber = MEM_readLE32(src);
3277     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
3278     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
3279 
3280     /* Loop on each block */
3281     while (1)
3282     {
3283         size_t decodedSize=0;
3284         size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &blockProperties);
3285         if (ZSTD_isError(cBlockSize)) return cBlockSize;
3286 
3287         ip += ZSTD_blockHeaderSize;
3288         remainingSize -= ZSTD_blockHeaderSize;
3289         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
3290 
3291         switch(blockProperties.blockType)
3292         {
3293         case bt_compressed:
3294             decodedSize = ZSTD_decompressBlock(ctx, op, oend-op, ip, cBlockSize);
3295             break;
3296         case bt_raw :
3297             decodedSize = ZSTD_copyUncompressedBlock(op, oend-op, ip, cBlockSize);
3298             break;
3299         case bt_rle :
3300             return ERROR(GENERIC);   /* not yet supported */
3301             break;
3302         case bt_end :
3303             /* end of frame */
3304             if (remainingSize) return ERROR(srcSize_wrong);
3305             break;
3306         default:
3307             return ERROR(GENERIC);   /* impossible */
3308         }
3309         if (cBlockSize == 0) break;   /* bt_end */
3310 
3311         if (ZSTD_isError(decodedSize)) return decodedSize;
3312         op += decodedSize;
3313         ip += cBlockSize;
3314         remainingSize -= cBlockSize;
3315     }
3316 
3317     return op-ostart;
3318 }
3319 
3320 static size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3321 {
3322     ZSTD_DCtx ctx;
3323     ctx.base = dst;
3324     return ZSTD_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
3325 }
3326 
3327 /* ZSTD_errorFrameSizeInfoLegacy() :
3328    assumes `cSize` and `dBound` are _not_ NULL */
3329 static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
3330 {
3331     *cSize = ret;
3332     *dBound = ZSTD_CONTENTSIZE_ERROR;
3333 }
3334 
3335 void ZSTDv02_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
3336 {
3337     const BYTE* ip = (const BYTE*)src;
3338     size_t remainingSize = srcSize;
3339     size_t nbBlocks = 0;
3340     U32 magicNumber;
3341     blockProperties_t blockProperties;
3342 
3343     /* Frame Header */
3344     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) {
3345         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3346         return;
3347     }
3348     magicNumber = MEM_readLE32(src);
3349     if (magicNumber != ZSTD_magicNumber) {
3350         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
3351         return;
3352     }
3353     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
3354 
3355     /* Loop on each block */
3356     while (1)
3357     {
3358         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
3359         if (ZSTD_isError(cBlockSize)) {
3360             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
3361             return;
3362         }
3363 
3364         ip += ZSTD_blockHeaderSize;
3365         remainingSize -= ZSTD_blockHeaderSize;
3366         if (cBlockSize > remainingSize) {
3367             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3368             return;
3369         }
3370 
3371         if (cBlockSize == 0) break;   /* bt_end */
3372 
3373         ip += cBlockSize;
3374         remainingSize -= cBlockSize;
3375         nbBlocks++;
3376     }
3377 
3378     *cSize = ip - (const BYTE*)src;
3379     *dBound = nbBlocks * BLOCKSIZE;
3380 }
3381 
3382 /*******************************
3383 *  Streaming Decompression API
3384 *******************************/
3385 
3386 static size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx)
3387 {
3388     dctx->expected = ZSTD_frameHeaderSize;
3389     dctx->phase = 0;
3390     dctx->previousDstEnd = NULL;
3391     dctx->base = NULL;
3392     return 0;
3393 }
3394 
3395 static ZSTD_DCtx* ZSTD_createDCtx(void)
3396 {
3397     ZSTD_DCtx* dctx = (ZSTD_DCtx*)malloc(sizeof(ZSTD_DCtx));
3398     if (dctx==NULL) return NULL;
3399     ZSTD_resetDCtx(dctx);
3400     return dctx;
3401 }
3402 
3403 static size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
3404 {
3405     free(dctx);
3406     return 0;
3407 }
3408 
3409 static size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx)
3410 {
3411     return dctx->expected;
3412 }
3413 
3414 static size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3415 {
3416     /* Sanity check */
3417     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
3418     if (dst != ctx->previousDstEnd)  /* not contiguous */
3419         ctx->base = dst;
3420 
3421     /* Decompress : frame header */
3422     if (ctx->phase == 0)
3423     {
3424         /* Check frame magic header */
3425         U32 magicNumber = MEM_readLE32(src);
3426         if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
3427         ctx->phase = 1;
3428         ctx->expected = ZSTD_blockHeaderSize;
3429         return 0;
3430     }
3431 
3432     /* Decompress : block header */
3433     if (ctx->phase == 1)
3434     {
3435         blockProperties_t bp;
3436         size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
3437         if (ZSTD_isError(blockSize)) return blockSize;
3438         if (bp.blockType == bt_end)
3439         {
3440             ctx->expected = 0;
3441             ctx->phase = 0;
3442         }
3443         else
3444         {
3445             ctx->expected = blockSize;
3446             ctx->bType = bp.blockType;
3447             ctx->phase = 2;
3448         }
3449 
3450         return 0;
3451     }
3452 
3453     /* Decompress : block content */
3454     {
3455         size_t rSize;
3456         switch(ctx->bType)
3457         {
3458         case bt_compressed:
3459             rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
3460             break;
3461         case bt_raw :
3462             rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize);
3463             break;
3464         case bt_rle :
3465             return ERROR(GENERIC);   /* not yet handled */
3466             break;
3467         case bt_end :   /* should never happen (filtered at phase 1) */
3468             rSize = 0;
3469             break;
3470         default:
3471             return ERROR(GENERIC);
3472         }
3473         ctx->phase = 1;
3474         ctx->expected = ZSTD_blockHeaderSize;
3475         ctx->previousDstEnd = (void*)( ((char*)dst) + rSize);
3476         return rSize;
3477     }
3478 
3479 }
3480 
3481 
3482 /* wrapper layer */
3483 
3484 unsigned ZSTDv02_isError(size_t code)
3485 {
3486     return ZSTD_isError(code);
3487 }
3488 
3489 size_t ZSTDv02_decompress( void* dst, size_t maxOriginalSize,
3490                      const void* src, size_t compressedSize)
3491 {
3492     return ZSTD_decompress(dst, maxOriginalSize, src, compressedSize);
3493 }
3494 
3495 ZSTDv02_Dctx* ZSTDv02_createDCtx(void)
3496 {
3497     return (ZSTDv02_Dctx*)ZSTD_createDCtx();
3498 }
3499 
3500 size_t ZSTDv02_freeDCtx(ZSTDv02_Dctx* dctx)
3501 {
3502     return ZSTD_freeDCtx((ZSTD_DCtx*)dctx);
3503 }
3504 
3505 size_t ZSTDv02_resetDCtx(ZSTDv02_Dctx* dctx)
3506 {
3507     return ZSTD_resetDCtx((ZSTD_DCtx*)dctx);
3508 }
3509 
3510 size_t ZSTDv02_nextSrcSizeToDecompress(ZSTDv02_Dctx* dctx)
3511 {
3512     return ZSTD_nextSrcSizeToDecompress((ZSTD_DCtx*)dctx);
3513 }
3514 
3515 size_t ZSTDv02_decompressContinue(ZSTDv02_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3516 {
3517     return ZSTD_decompressContinue((ZSTD_DCtx*)dctx, dst, maxDstSize, src, srcSize);
3518 }
3519