xref: /freebsd/sys/contrib/zstd/lib/legacy/zstd_v07.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*
2  * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
3  * All rights reserved.
4  *
5  * This source code is licensed under both the BSD-style license (found in the
6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7  * in the COPYING file in the root directory of this source tree).
8  * You may select, at your option, one of the above-listed licenses.
9  */
10 
11 
12 /*- Dependencies -*/
13 #include <stddef.h>     /* size_t, ptrdiff_t */
14 #include <string.h>     /* memcpy */
15 #include <stdlib.h>     /* malloc, free, qsort */
16 
17 #ifndef XXH_STATIC_LINKING_ONLY
18 #  define XXH_STATIC_LINKING_ONLY    /* XXH64_state_t */
19 #endif
20 #include "../common/xxhash.h"                  /* XXH64_* */
21 #include "zstd_v07.h"
22 
23 #define FSEv07_STATIC_LINKING_ONLY   /* FSEv07_MIN_TABLELOG */
24 #define HUFv07_STATIC_LINKING_ONLY   /* HUFv07_TABLELOG_ABSOLUTEMAX */
25 #define ZSTDv07_STATIC_LINKING_ONLY
26 
27 #include "../common/error_private.h"
28 
29 
30 #ifdef ZSTDv07_STATIC_LINKING_ONLY
31 
32 /* ====================================================================================
33  * The definitions in this section are considered experimental.
34  * They should never be used with a dynamic library, as they may change in the future.
35  * They are provided for advanced usages.
36  * Use them only in association with static linking.
37  * ==================================================================================== */
38 
39 /*--- Constants ---*/
40 #define ZSTDv07_MAGIC_SKIPPABLE_START  0x184D2A50U
41 
42 #define ZSTDv07_WINDOWLOG_MAX_32  25
43 #define ZSTDv07_WINDOWLOG_MAX_64  27
44 #define ZSTDv07_WINDOWLOG_MAX    ((U32)(MEM_32bits() ? ZSTDv07_WINDOWLOG_MAX_32 : ZSTDv07_WINDOWLOG_MAX_64))
45 #define ZSTDv07_WINDOWLOG_MIN     18
46 #define ZSTDv07_CHAINLOG_MAX     (ZSTDv07_WINDOWLOG_MAX+1)
47 #define ZSTDv07_CHAINLOG_MIN       4
48 #define ZSTDv07_HASHLOG_MAX       ZSTDv07_WINDOWLOG_MAX
49 #define ZSTDv07_HASHLOG_MIN       12
50 #define ZSTDv07_HASHLOG3_MAX      17
51 #define ZSTDv07_SEARCHLOG_MAX    (ZSTDv07_WINDOWLOG_MAX-1)
52 #define ZSTDv07_SEARCHLOG_MIN      1
53 #define ZSTDv07_SEARCHLENGTH_MAX   7
54 #define ZSTDv07_SEARCHLENGTH_MIN   3
55 #define ZSTDv07_TARGETLENGTH_MIN   4
56 #define ZSTDv07_TARGETLENGTH_MAX 999
57 
58 #define ZSTDv07_FRAMEHEADERSIZE_MAX 18    /* for static allocation */
59 static const size_t ZSTDv07_frameHeaderSize_min = 5;
60 static const size_t ZSTDv07_frameHeaderSize_max = ZSTDv07_FRAMEHEADERSIZE_MAX;
61 static const size_t ZSTDv07_skippableHeaderSize = 8;  /* magic number + skippable frame length */
62 
63 
64 /* custom memory allocation functions */
65 typedef void* (*ZSTDv07_allocFunction) (void* opaque, size_t size);
66 typedef void  (*ZSTDv07_freeFunction) (void* opaque, void* address);
67 typedef struct { ZSTDv07_allocFunction customAlloc; ZSTDv07_freeFunction customFree; void* opaque; } ZSTDv07_customMem;
68 
69 
70 /*--- Advanced Decompression functions ---*/
71 
72 /*! ZSTDv07_estimateDCtxSize() :
73  *  Gives the potential amount of memory allocated to create a ZSTDv07_DCtx */
74 ZSTDLIBv07_API size_t ZSTDv07_estimateDCtxSize(void);
75 
76 /*! ZSTDv07_createDCtx_advanced() :
77  *  Create a ZSTD decompression context using external alloc and free functions */
78 ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx_advanced(ZSTDv07_customMem customMem);
79 
80 /*! ZSTDv07_sizeofDCtx() :
81  *  Gives the amount of memory used by a given ZSTDv07_DCtx */
82 ZSTDLIBv07_API size_t ZSTDv07_sizeofDCtx(const ZSTDv07_DCtx* dctx);
83 
84 
85 /* ******************************************************************
86 *  Buffer-less streaming functions (synchronous mode)
87 ********************************************************************/
88 
89 ZSTDLIBv07_API size_t ZSTDv07_decompressBegin(ZSTDv07_DCtx* dctx);
90 ZSTDLIBv07_API size_t ZSTDv07_decompressBegin_usingDict(ZSTDv07_DCtx* dctx, const void* dict, size_t dictSize);
91 ZSTDLIBv07_API void   ZSTDv07_copyDCtx(ZSTDv07_DCtx* dctx, const ZSTDv07_DCtx* preparedDCtx);
92 
93 ZSTDLIBv07_API size_t ZSTDv07_nextSrcSizeToDecompress(ZSTDv07_DCtx* dctx);
94 ZSTDLIBv07_API size_t ZSTDv07_decompressContinue(ZSTDv07_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
95 
96 /*
97   Buffer-less streaming decompression (synchronous mode)
98 
99   A ZSTDv07_DCtx object is required to track streaming operations.
100   Use ZSTDv07_createDCtx() / ZSTDv07_freeDCtx() to manage it.
101   A ZSTDv07_DCtx object can be re-used multiple times.
102 
103   First optional operation is to retrieve frame parameters, using ZSTDv07_getFrameParams(), which doesn't consume the input.
104   It can provide the minimum size of rolling buffer required to properly decompress data (`windowSize`),
105   and optionally the final size of uncompressed content.
106   (Note : content size is an optional info that may not be present. 0 means : content size unknown)
107   Frame parameters are extracted from the beginning of compressed frame.
108   The amount of data to read is variable, from ZSTDv07_frameHeaderSize_min to ZSTDv07_frameHeaderSize_max (so if `srcSize` >= ZSTDv07_frameHeaderSize_max, it will always work)
109   If `srcSize` is too small for operation to succeed, function will return the minimum size it requires to produce a result.
110   Result : 0 when successful, it means the ZSTDv07_frameParams structure has been filled.
111           >0 : means there is not enough data into `src`. Provides the expected size to successfully decode header.
112            errorCode, which can be tested using ZSTDv07_isError()
113 
114   Start decompression, with ZSTDv07_decompressBegin() or ZSTDv07_decompressBegin_usingDict().
115   Alternatively, you can copy a prepared context, using ZSTDv07_copyDCtx().
116 
117   Then use ZSTDv07_nextSrcSizeToDecompress() and ZSTDv07_decompressContinue() alternatively.
118   ZSTDv07_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTDv07_decompressContinue().
119   ZSTDv07_decompressContinue() requires this exact amount of bytes, or it will fail.
120 
121   @result of ZSTDv07_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
122   It can be zero, which is not an error; it just means ZSTDv07_decompressContinue() has decoded some header.
123 
124   ZSTDv07_decompressContinue() needs previous data blocks during decompression, up to `windowSize`.
125   They should preferably be located contiguously, prior to current block.
126   Alternatively, a round buffer of sufficient size is also possible. Sufficient size is determined by frame parameters.
127   ZSTDv07_decompressContinue() is very sensitive to contiguity,
128   if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
129     or that previous contiguous segment is large enough to properly handle maximum back-reference.
130 
131   A frame is fully decoded when ZSTDv07_nextSrcSizeToDecompress() returns zero.
132   Context can then be reset to start a new decompression.
133 
134 
135   == Special case : skippable frames ==
136 
137   Skippable frames allow the integration of user-defined data into a flow of concatenated frames.
138   Skippable frames will be ignored (skipped) by a decompressor. The format of skippable frame is following:
139   a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
140   b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
141   c) Frame Content - any content (User Data) of length equal to Frame Size
142   For skippable frames ZSTDv07_decompressContinue() always returns 0.
143   For skippable frames ZSTDv07_getFrameParams() returns fparamsPtr->windowLog==0 what means that a frame is skippable.
144   It also returns Frame Size as fparamsPtr->frameContentSize.
145 */
146 
147 
148 /* **************************************
149 *  Block functions
150 ****************************************/
151 /*! Block functions produce and decode raw zstd blocks, without frame metadata.
152     Frame metadata cost is typically ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes).
153     User will have to take in charge required information to regenerate data, such as compressed and content sizes.
154 
155     A few rules to respect :
156     - Compressing and decompressing require a context structure
157       + Use ZSTDv07_createCCtx() and ZSTDv07_createDCtx()
158     - It is necessary to init context before starting
159       + compression : ZSTDv07_compressBegin()
160       + decompression : ZSTDv07_decompressBegin()
161       + variants _usingDict() are also allowed
162       + copyCCtx() and copyDCtx() work too
163     - Block size is limited, it must be <= ZSTDv07_getBlockSizeMax()
164       + If you need to compress more, cut data into multiple blocks
165       + Consider using the regular ZSTDv07_compress() instead, as frame metadata costs become negligible when source size is large.
166     - When a block is considered not compressible enough, ZSTDv07_compressBlock() result will be zero.
167       In which case, nothing is produced into `dst`.
168       + User must test for such outcome and deal directly with uncompressed data
169       + ZSTDv07_decompressBlock() doesn't accept uncompressed data as input !!!
170       + In case of multiple successive blocks, decoder must be informed of uncompressed block existence to follow proper history.
171         Use ZSTDv07_insertBlock() in such a case.
172 */
173 
174 #define ZSTDv07_BLOCKSIZE_ABSOLUTEMAX (128 * 1024)   /* define, for static allocation */
175 ZSTDLIBv07_API size_t ZSTDv07_decompressBlock(ZSTDv07_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
176 ZSTDLIBv07_API size_t ZSTDv07_insertBlock(ZSTDv07_DCtx* dctx, const void* blockStart, size_t blockSize);  /**< insert block into `dctx` history. Useful for uncompressed blocks */
177 
178 
179 #endif   /* ZSTDv07_STATIC_LINKING_ONLY */
180 
181 
182 /* ******************************************************************
183    mem.h
184    low-level memory access routines
185    Copyright (C) 2013-2015, Yann Collet.
186 
187    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
188 
189    Redistribution and use in source and binary forms, with or without
190    modification, are permitted provided that the following conditions are
191    met:
192 
193        * Redistributions of source code must retain the above copyright
194    notice, this list of conditions and the following disclaimer.
195        * Redistributions in binary form must reproduce the above
196    copyright notice, this list of conditions and the following disclaimer
197    in the documentation and/or other materials provided with the
198    distribution.
199 
200    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
201    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
202    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
203    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
204    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
205    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
206    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
207    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
208    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
209    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
210    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
211 
212     You can contact the author at :
213     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
214     - Public forum : https://groups.google.com/forum/#!forum/lz4c
215 ****************************************************************** */
216 #ifndef MEM_H_MODULE
217 #define MEM_H_MODULE
218 
219 #if defined (__cplusplus)
220 extern "C" {
221 #endif
222 
223 /*-****************************************
224 *  Compiler specifics
225 ******************************************/
226 #if defined(_MSC_VER)   /* Visual Studio */
227 #   include <stdlib.h>  /* _byteswap_ulong */
228 #   include <intrin.h>  /* _byteswap_* */
229 #endif
230 #if defined(__GNUC__)
231 #  define MEM_STATIC static __attribute__((unused))
232 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
233 #  define MEM_STATIC static inline
234 #elif defined(_MSC_VER)
235 #  define MEM_STATIC static __inline
236 #else
237 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
238 #endif
239 
240 
241 /*-**************************************************************
242 *  Basic Types
243 *****************************************************************/
244 #if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
245 # if defined(_AIX)
246 #  include <inttypes.h>
247 # else
248 #  include <stdint.h> /* intptr_t */
249 # endif
250   typedef  uint8_t BYTE;
251   typedef uint16_t U16;
252   typedef  int16_t S16;
253   typedef uint32_t U32;
254   typedef  int32_t S32;
255   typedef uint64_t U64;
256   typedef  int64_t S64;
257 #else
258   typedef unsigned char       BYTE;
259   typedef unsigned short      U16;
260   typedef   signed short      S16;
261   typedef unsigned int        U32;
262   typedef   signed int        S32;
263   typedef unsigned long long  U64;
264   typedef   signed long long  S64;
265 #endif
266 
267 
268 /*-**************************************************************
269 *  Memory I/O
270 *****************************************************************/
271 /* MEM_FORCE_MEMORY_ACCESS :
272  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
273  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
274  * The below switch allow to select different access method for improved performance.
275  * Method 0 (default) : use `memcpy()`. Safe and portable.
276  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
277  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
278  * Method 2 : direct access. This method is portable but violate C standard.
279  *            It can generate buggy code on targets depending on alignment.
280  *            In some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
281  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
282  * Prefer these methods in priority order (0 > 1 > 2)
283  */
284 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
285 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
286 #    define MEM_FORCE_MEMORY_ACCESS 2
287 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
288   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
289 #    define MEM_FORCE_MEMORY_ACCESS 1
290 #  endif
291 #endif
292 
293 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
294 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }
295 
296 MEM_STATIC unsigned MEM_isLittleEndian(void)
297 {
298     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
299     return one.c[0];
300 }
301 
302 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
303 
304 /* violates C standard, by lying on structure alignment.
305 Only use if no other choice to achieve best performance on target platform */
306 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
307 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
308 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
309 
310 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
311 
312 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
313 
314 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
315 /* currently only defined for gcc and icc */
316 typedef union { U16 u16; U32 u32; U64 u64; size_t st; } __attribute__((packed)) unalign;
317 
318 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
319 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
320 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
321 
322 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
323 
324 #else
325 
326 /* default method, safe and standard.
327    can sometimes prove slower */
328 
329 MEM_STATIC U16 MEM_read16(const void* memPtr)
330 {
331     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
332 }
333 
334 MEM_STATIC U32 MEM_read32(const void* memPtr)
335 {
336     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
337 }
338 
339 MEM_STATIC U64 MEM_read64(const void* memPtr)
340 {
341     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
342 }
343 
344 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
345 {
346     memcpy(memPtr, &value, sizeof(value));
347 }
348 
349 #endif /* MEM_FORCE_MEMORY_ACCESS */
350 
351 MEM_STATIC U32 MEM_swap32(U32 in)
352 {
353 #if defined(_MSC_VER)     /* Visual Studio */
354     return _byteswap_ulong(in);
355 #elif defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)
356     return __builtin_bswap32(in);
357 #else
358     return  ((in << 24) & 0xff000000 ) |
359             ((in <<  8) & 0x00ff0000 ) |
360             ((in >>  8) & 0x0000ff00 ) |
361             ((in >> 24) & 0x000000ff );
362 #endif
363 }
364 
365 MEM_STATIC U64 MEM_swap64(U64 in)
366 {
367 #if defined(_MSC_VER)     /* Visual Studio */
368     return _byteswap_uint64(in);
369 #elif defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)
370     return __builtin_bswap64(in);
371 #else
372     return  ((in << 56) & 0xff00000000000000ULL) |
373             ((in << 40) & 0x00ff000000000000ULL) |
374             ((in << 24) & 0x0000ff0000000000ULL) |
375             ((in << 8)  & 0x000000ff00000000ULL) |
376             ((in >> 8)  & 0x00000000ff000000ULL) |
377             ((in >> 24) & 0x0000000000ff0000ULL) |
378             ((in >> 40) & 0x000000000000ff00ULL) |
379             ((in >> 56) & 0x00000000000000ffULL);
380 #endif
381 }
382 
383 
384 /*=== Little endian r/w ===*/
385 
386 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
387 {
388     if (MEM_isLittleEndian())
389         return MEM_read16(memPtr);
390     else {
391         const BYTE* p = (const BYTE*)memPtr;
392         return (U16)(p[0] + (p[1]<<8));
393     }
394 }
395 
396 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
397 {
398     if (MEM_isLittleEndian()) {
399         MEM_write16(memPtr, val);
400     } else {
401         BYTE* p = (BYTE*)memPtr;
402         p[0] = (BYTE)val;
403         p[1] = (BYTE)(val>>8);
404     }
405 }
406 
407 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
408 {
409     if (MEM_isLittleEndian())
410         return MEM_read32(memPtr);
411     else
412         return MEM_swap32(MEM_read32(memPtr));
413 }
414 
415 
416 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
417 {
418     if (MEM_isLittleEndian())
419         return MEM_read64(memPtr);
420     else
421         return MEM_swap64(MEM_read64(memPtr));
422 }
423 
424 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
425 {
426     if (MEM_32bits())
427         return (size_t)MEM_readLE32(memPtr);
428     else
429         return (size_t)MEM_readLE64(memPtr);
430 }
431 
432 
433 
434 #if defined (__cplusplus)
435 }
436 #endif
437 
438 #endif /* MEM_H_MODULE */
439 /* ******************************************************************
440    bitstream
441    Part of FSE library
442    header file (to include)
443    Copyright (C) 2013-2016, Yann Collet.
444 
445    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
446 
447    Redistribution and use in source and binary forms, with or without
448    modification, are permitted provided that the following conditions are
449    met:
450 
451        * Redistributions of source code must retain the above copyright
452    notice, this list of conditions and the following disclaimer.
453        * Redistributions in binary form must reproduce the above
454    copyright notice, this list of conditions and the following disclaimer
455    in the documentation and/or other materials provided with the
456    distribution.
457 
458    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
459    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
460    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
461    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
462    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
463    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
464    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
465    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
466    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
467    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
468    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
469 
470    You can contact the author at :
471    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
472 ****************************************************************** */
473 #ifndef BITSTREAM_H_MODULE
474 #define BITSTREAM_H_MODULE
475 
476 #if defined (__cplusplus)
477 extern "C" {
478 #endif
479 
480 
481 /*
482 *  This API consists of small unitary functions, which must be inlined for best performance.
483 *  Since link-time-optimization is not available for all compilers,
484 *  these functions are defined into a .h to be included.
485 */
486 
487 
488 /*=========================================
489 *  Target specific
490 =========================================*/
491 #if defined(__BMI__) && defined(__GNUC__)
492 #  include <immintrin.h>   /* support for bextr (experimental) */
493 #endif
494 
495 /*-********************************************
496 *  bitStream decoding API (read backward)
497 **********************************************/
498 typedef struct
499 {
500     size_t   bitContainer;
501     unsigned bitsConsumed;
502     const char* ptr;
503     const char* start;
504 } BITv07_DStream_t;
505 
506 typedef enum { BITv07_DStream_unfinished = 0,
507                BITv07_DStream_endOfBuffer = 1,
508                BITv07_DStream_completed = 2,
509                BITv07_DStream_overflow = 3 } BITv07_DStream_status;  /* result of BITv07_reloadDStream() */
510                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
511 
512 MEM_STATIC size_t   BITv07_initDStream(BITv07_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
513 MEM_STATIC size_t   BITv07_readBits(BITv07_DStream_t* bitD, unsigned nbBits);
514 MEM_STATIC BITv07_DStream_status BITv07_reloadDStream(BITv07_DStream_t* bitD);
515 MEM_STATIC unsigned BITv07_endOfDStream(const BITv07_DStream_t* bitD);
516 
517 
518 
519 /*-****************************************
520 *  unsafe API
521 ******************************************/
522 MEM_STATIC size_t BITv07_readBitsFast(BITv07_DStream_t* bitD, unsigned nbBits);
523 /* faster, but works only if nbBits >= 1 */
524 
525 
526 
527 /*-**************************************************************
528 *  Internal functions
529 ****************************************************************/
530 MEM_STATIC unsigned BITv07_highbit32 (U32 val)
531 {
532 #   if defined(_MSC_VER)   /* Visual */
533     unsigned long r=0;
534     _BitScanReverse ( &r, val );
535     return (unsigned) r;
536 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
537     return __builtin_clz (val) ^ 31;
538 #   else   /* Software version */
539     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 };
540     U32 v = val;
541     v |= v >> 1;
542     v |= v >> 2;
543     v |= v >> 4;
544     v |= v >> 8;
545     v |= v >> 16;
546     return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
547 #   endif
548 }
549 
550 
551 
552 /*-********************************************************
553 * bitStream decoding
554 **********************************************************/
555 /*! BITv07_initDStream() :
556 *   Initialize a BITv07_DStream_t.
557 *   `bitD` : a pointer to an already allocated BITv07_DStream_t structure.
558 *   `srcSize` must be the *exact* size of the bitStream, in bytes.
559 *   @return : size of stream (== srcSize) or an errorCode if a problem is detected
560 */
561 MEM_STATIC size_t BITv07_initDStream(BITv07_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
562 {
563     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
564 
565     if (srcSize >=  sizeof(bitD->bitContainer)) {  /* normal case */
566         bitD->start = (const char*)srcBuffer;
567         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(bitD->bitContainer);
568         bitD->bitContainer = MEM_readLEST(bitD->ptr);
569         { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
570           bitD->bitsConsumed = lastByte ? 8 - BITv07_highbit32(lastByte) : 0;
571           if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
572     } else {
573         bitD->start = (const char*)srcBuffer;
574         bitD->ptr   = bitD->start;
575         bitD->bitContainer = *(const BYTE*)(bitD->start);
576         switch(srcSize)
577         {
578             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);/* fall-through */
579             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);/* fall-through */
580             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);/* fall-through */
581             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24; /* fall-through */
582             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16; /* fall-through */
583             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) <<  8; /* fall-through */
584             default: break;
585         }
586         { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
587           bitD->bitsConsumed = lastByte ? 8 - BITv07_highbit32(lastByte) : 0;
588           if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
589         bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize)*8;
590     }
591 
592     return srcSize;
593 }
594 
595 
596  MEM_STATIC size_t BITv07_lookBits(const BITv07_DStream_t* bitD, U32 nbBits)
597 {
598     U32 const bitMask = sizeof(bitD->bitContainer)*8 - 1;
599     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
600 }
601 
602 /*! BITv07_lookBitsFast() :
603 *   unsafe version; only works only if nbBits >= 1 */
604 MEM_STATIC size_t BITv07_lookBitsFast(const BITv07_DStream_t* bitD, U32 nbBits)
605 {
606     U32 const bitMask = sizeof(bitD->bitContainer)*8 - 1;
607     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
608 }
609 
610 MEM_STATIC void BITv07_skipBits(BITv07_DStream_t* bitD, U32 nbBits)
611 {
612     bitD->bitsConsumed += nbBits;
613 }
614 
615 MEM_STATIC size_t BITv07_readBits(BITv07_DStream_t* bitD, U32 nbBits)
616 {
617     size_t const value = BITv07_lookBits(bitD, nbBits);
618     BITv07_skipBits(bitD, nbBits);
619     return value;
620 }
621 
622 /*! BITv07_readBitsFast() :
623 *   unsafe version; only works only if nbBits >= 1 */
624 MEM_STATIC size_t BITv07_readBitsFast(BITv07_DStream_t* bitD, U32 nbBits)
625 {
626     size_t const value = BITv07_lookBitsFast(bitD, nbBits);
627     BITv07_skipBits(bitD, nbBits);
628     return value;
629 }
630 
631 MEM_STATIC BITv07_DStream_status BITv07_reloadDStream(BITv07_DStream_t* bitD)
632 {
633     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should not happen => corruption detected */
634         return BITv07_DStream_overflow;
635 
636     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer)) {
637         bitD->ptr -= bitD->bitsConsumed >> 3;
638         bitD->bitsConsumed &= 7;
639         bitD->bitContainer = MEM_readLEST(bitD->ptr);
640         return BITv07_DStream_unfinished;
641     }
642     if (bitD->ptr == bitD->start) {
643         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BITv07_DStream_endOfBuffer;
644         return BITv07_DStream_completed;
645     }
646     {   U32 nbBytes = bitD->bitsConsumed >> 3;
647         BITv07_DStream_status result = BITv07_DStream_unfinished;
648         if (bitD->ptr - nbBytes < bitD->start) {
649             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
650             result = BITv07_DStream_endOfBuffer;
651         }
652         bitD->ptr -= nbBytes;
653         bitD->bitsConsumed -= nbBytes*8;
654         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
655         return result;
656     }
657 }
658 
659 /*! BITv07_endOfDStream() :
660 *   @return Tells if DStream has exactly reached its end (all bits consumed).
661 */
662 MEM_STATIC unsigned BITv07_endOfDStream(const BITv07_DStream_t* DStream)
663 {
664     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
665 }
666 
667 #if defined (__cplusplus)
668 }
669 #endif
670 
671 #endif /* BITSTREAM_H_MODULE */
672 /* ******************************************************************
673    FSE : Finite State Entropy codec
674    Public Prototypes declaration
675    Copyright (C) 2013-2016, Yann Collet.
676 
677    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
678 
679    Redistribution and use in source and binary forms, with or without
680    modification, are permitted provided that the following conditions are
681    met:
682 
683        * Redistributions of source code must retain the above copyright
684    notice, this list of conditions and the following disclaimer.
685        * Redistributions in binary form must reproduce the above
686    copyright notice, this list of conditions and the following disclaimer
687    in the documentation and/or other materials provided with the
688    distribution.
689 
690    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
691    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
692    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
693    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
694    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
695    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
696    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
697    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
698    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
699    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
700    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
701 
702    You can contact the author at :
703    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
704 ****************************************************************** */
705 #ifndef FSEv07_H
706 #define FSEv07_H
707 
708 #if defined (__cplusplus)
709 extern "C" {
710 #endif
711 
712 
713 
714 /*-****************************************
715 *  FSE simple functions
716 ******************************************/
717 
718 /*! FSEv07_decompress():
719     Decompress FSE data from buffer 'cSrc', of size 'cSrcSize',
720     into already allocated destination buffer 'dst', of size 'dstCapacity'.
721     @return : size of regenerated data (<= maxDstSize),
722               or an error code, which can be tested using FSEv07_isError() .
723 
724     ** Important ** : FSEv07_decompress() does not decompress non-compressible nor RLE data !!!
725     Why ? : making this distinction requires a header.
726     Header management is intentionally delegated to the user layer, which can better manage special cases.
727 */
728 size_t FSEv07_decompress(void* dst,  size_t dstCapacity,
729                 const void* cSrc, size_t cSrcSize);
730 
731 
732 /* Error Management */
733 unsigned    FSEv07_isError(size_t code);        /* tells if a return value is an error code */
734 const char* FSEv07_getErrorName(size_t code);   /* provides error code string (useful for debugging) */
735 
736 
737 /*-*****************************************
738 *  FSE detailed API
739 ******************************************/
740 /*!
741 FSEv07_decompress() does the following:
742 1. read normalized counters with readNCount()
743 2. build decoding table 'DTable' from normalized counters
744 3. decode the data stream using decoding table 'DTable'
745 
746 The following API allows targeting specific sub-functions for advanced tasks.
747 For example, it's possible to compress several blocks using the same 'CTable',
748 or to save and provide normalized distribution using external method.
749 */
750 
751 
752 /* *** DECOMPRESSION *** */
753 
754 /*! FSEv07_readNCount():
755     Read compactly saved 'normalizedCounter' from 'rBuffer'.
756     @return : size read from 'rBuffer',
757               or an errorCode, which can be tested using FSEv07_isError().
758               maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
759 size_t FSEv07_readNCount (short* normalizedCounter, unsigned* maxSymbolValuePtr, unsigned* tableLogPtr, const void* rBuffer, size_t rBuffSize);
760 
761 /*! Constructor and Destructor of FSEv07_DTable.
762     Note that its size depends on 'tableLog' */
763 typedef unsigned FSEv07_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
764 FSEv07_DTable* FSEv07_createDTable(unsigned tableLog);
765 void        FSEv07_freeDTable(FSEv07_DTable* dt);
766 
767 /*! FSEv07_buildDTable():
768     Builds 'dt', which must be already allocated, using FSEv07_createDTable().
769     return : 0, or an errorCode, which can be tested using FSEv07_isError() */
770 size_t FSEv07_buildDTable (FSEv07_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
771 
772 /*! FSEv07_decompress_usingDTable():
773     Decompress compressed source `cSrc` of size `cSrcSize` using `dt`
774     into `dst` which must be already allocated.
775     @return : size of regenerated data (necessarily <= `dstCapacity`),
776               or an errorCode, which can be tested using FSEv07_isError() */
777 size_t FSEv07_decompress_usingDTable(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, const FSEv07_DTable* dt);
778 
779 /*!
780 Tutorial :
781 ----------
782 (Note : these functions only decompress FSE-compressed blocks.
783  If block is uncompressed, use memcpy() instead
784  If block is a single repeated byte, use memset() instead )
785 
786 The first step is to obtain the normalized frequencies of symbols.
787 This can be performed by FSEv07_readNCount() if it was saved using FSEv07_writeNCount().
788 'normalizedCounter' must be already allocated, and have at least 'maxSymbolValuePtr[0]+1' cells of signed short.
789 In practice, that means it's necessary to know 'maxSymbolValue' beforehand,
790 or size the table to handle worst case situations (typically 256).
791 FSEv07_readNCount() will provide 'tableLog' and 'maxSymbolValue'.
792 The result of FSEv07_readNCount() is the number of bytes read from 'rBuffer'.
793 Note that 'rBufferSize' must be at least 4 bytes, even if useful information is less than that.
794 If there is an error, the function will return an error code, which can be tested using FSEv07_isError().
795 
796 The next step is to build the decompression tables 'FSEv07_DTable' from 'normalizedCounter'.
797 This is performed by the function FSEv07_buildDTable().
798 The space required by 'FSEv07_DTable' must be already allocated using FSEv07_createDTable().
799 If there is an error, the function will return an error code, which can be tested using FSEv07_isError().
800 
801 `FSEv07_DTable` can then be used to decompress `cSrc`, with FSEv07_decompress_usingDTable().
802 `cSrcSize` must be strictly correct, otherwise decompression will fail.
803 FSEv07_decompress_usingDTable() result will tell how many bytes were regenerated (<=`dstCapacity`).
804 If there is an error, the function will return an error code, which can be tested using FSEv07_isError(). (ex: dst buffer too small)
805 */
806 
807 
808 #ifdef FSEv07_STATIC_LINKING_ONLY
809 
810 
811 /* *****************************************
812 *  Static allocation
813 *******************************************/
814 /* FSE buffer bounds */
815 #define FSEv07_NCOUNTBOUND 512
816 #define FSEv07_BLOCKBOUND(size) (size + (size>>7))
817 
818 /* It is possible to statically allocate FSE CTable/DTable as a table of unsigned using below macros */
819 #define FSEv07_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<maxTableLog))
820 
821 
822 /* *****************************************
823 *  FSE advanced API
824 *******************************************/
825 size_t FSEv07_countFast(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
826 /**< same as FSEv07_count(), but blindly trusts that all byte values within src are <= *maxSymbolValuePtr  */
827 
828 unsigned FSEv07_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus);
829 /**< same as FSEv07_optimalTableLog(), which used `minus==2` */
830 
831 size_t FSEv07_buildDTable_raw (FSEv07_DTable* dt, unsigned nbBits);
832 /**< build a fake FSEv07_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
833 
834 size_t FSEv07_buildDTable_rle (FSEv07_DTable* dt, unsigned char symbolValue);
835 /**< build a fake FSEv07_DTable, designed to always generate the same symbolValue */
836 
837 
838 
839 /* *****************************************
840 *  FSE symbol decompression API
841 *******************************************/
842 typedef struct
843 {
844     size_t      state;
845     const void* table;   /* precise table may vary, depending on U16 */
846 } FSEv07_DState_t;
847 
848 
849 static void     FSEv07_initDState(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD, const FSEv07_DTable* dt);
850 
851 static unsigned char FSEv07_decodeSymbol(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD);
852 
853 
854 
855 /* *****************************************
856 *  FSE unsafe API
857 *******************************************/
858 static unsigned char FSEv07_decodeSymbolFast(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD);
859 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
860 
861 
862 /* ======    Decompression    ====== */
863 
864 typedef struct {
865     U16 tableLog;
866     U16 fastMode;
867 } FSEv07_DTableHeader;   /* sizeof U32 */
868 
869 typedef struct
870 {
871     unsigned short newState;
872     unsigned char  symbol;
873     unsigned char  nbBits;
874 } FSEv07_decode_t;   /* size == U32 */
875 
876 MEM_STATIC void FSEv07_initDState(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD, const FSEv07_DTable* dt)
877 {
878     const void* ptr = dt;
879     const FSEv07_DTableHeader* const DTableH = (const FSEv07_DTableHeader*)ptr;
880     DStatePtr->state = BITv07_readBits(bitD, DTableH->tableLog);
881     BITv07_reloadDStream(bitD);
882     DStatePtr->table = dt + 1;
883 }
884 
885 MEM_STATIC BYTE FSEv07_peekSymbol(const FSEv07_DState_t* DStatePtr)
886 {
887     FSEv07_decode_t const DInfo = ((const FSEv07_decode_t*)(DStatePtr->table))[DStatePtr->state];
888     return DInfo.symbol;
889 }
890 
891 MEM_STATIC void FSEv07_updateState(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD)
892 {
893     FSEv07_decode_t const DInfo = ((const FSEv07_decode_t*)(DStatePtr->table))[DStatePtr->state];
894     U32 const nbBits = DInfo.nbBits;
895     size_t const lowBits = BITv07_readBits(bitD, nbBits);
896     DStatePtr->state = DInfo.newState + lowBits;
897 }
898 
899 MEM_STATIC BYTE FSEv07_decodeSymbol(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD)
900 {
901     FSEv07_decode_t const DInfo = ((const FSEv07_decode_t*)(DStatePtr->table))[DStatePtr->state];
902     U32 const nbBits = DInfo.nbBits;
903     BYTE const symbol = DInfo.symbol;
904     size_t const lowBits = BITv07_readBits(bitD, nbBits);
905 
906     DStatePtr->state = DInfo.newState + lowBits;
907     return symbol;
908 }
909 
910 /*! FSEv07_decodeSymbolFast() :
911     unsafe, only works if no symbol has a probability > 50% */
912 MEM_STATIC BYTE FSEv07_decodeSymbolFast(FSEv07_DState_t* DStatePtr, BITv07_DStream_t* bitD)
913 {
914     FSEv07_decode_t const DInfo = ((const FSEv07_decode_t*)(DStatePtr->table))[DStatePtr->state];
915     U32 const nbBits = DInfo.nbBits;
916     BYTE const symbol = DInfo.symbol;
917     size_t const lowBits = BITv07_readBitsFast(bitD, nbBits);
918 
919     DStatePtr->state = DInfo.newState + lowBits;
920     return symbol;
921 }
922 
923 
924 
925 #ifndef FSEv07_COMMONDEFS_ONLY
926 
927 /* **************************************************************
928 *  Tuning parameters
929 ****************************************************************/
930 /*!MEMORY_USAGE :
931 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
932 *  Increasing memory usage improves compression ratio
933 *  Reduced memory usage can improve speed, due to cache effect
934 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
935 #define FSEv07_MAX_MEMORY_USAGE 14
936 #define FSEv07_DEFAULT_MEMORY_USAGE 13
937 
938 /*!FSEv07_MAX_SYMBOL_VALUE :
939 *  Maximum symbol value authorized.
940 *  Required for proper stack allocation */
941 #define FSEv07_MAX_SYMBOL_VALUE 255
942 
943 
944 /* **************************************************************
945 *  template functions type & suffix
946 ****************************************************************/
947 #define FSEv07_FUNCTION_TYPE BYTE
948 #define FSEv07_FUNCTION_EXTENSION
949 #define FSEv07_DECODE_TYPE FSEv07_decode_t
950 
951 
952 #endif   /* !FSEv07_COMMONDEFS_ONLY */
953 
954 
955 /* ***************************************************************
956 *  Constants
957 *****************************************************************/
958 #define FSEv07_MAX_TABLELOG  (FSEv07_MAX_MEMORY_USAGE-2)
959 #define FSEv07_MAX_TABLESIZE (1U<<FSEv07_MAX_TABLELOG)
960 #define FSEv07_MAXTABLESIZE_MASK (FSEv07_MAX_TABLESIZE-1)
961 #define FSEv07_DEFAULT_TABLELOG (FSEv07_DEFAULT_MEMORY_USAGE-2)
962 #define FSEv07_MIN_TABLELOG 5
963 
964 #define FSEv07_TABLELOG_ABSOLUTE_MAX 15
965 #if FSEv07_MAX_TABLELOG > FSEv07_TABLELOG_ABSOLUTE_MAX
966 #  error "FSEv07_MAX_TABLELOG > FSEv07_TABLELOG_ABSOLUTE_MAX is not supported"
967 #endif
968 
969 #define FSEv07_TABLESTEP(tableSize) ((tableSize>>1) + (tableSize>>3) + 3)
970 
971 
972 #endif /* FSEv07_STATIC_LINKING_ONLY */
973 
974 
975 #if defined (__cplusplus)
976 }
977 #endif
978 
979 #endif  /* FSEv07_H */
980 /* ******************************************************************
981    Huffman coder, part of New Generation Entropy library
982    header file
983    Copyright (C) 2013-2016, Yann Collet.
984 
985    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
986 
987    Redistribution and use in source and binary forms, with or without
988    modification, are permitted provided that the following conditions are
989    met:
990 
991        * Redistributions of source code must retain the above copyright
992    notice, this list of conditions and the following disclaimer.
993        * Redistributions in binary form must reproduce the above
994    copyright notice, this list of conditions and the following disclaimer
995    in the documentation and/or other materials provided with the
996    distribution.
997 
998    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
999    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1000    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1001    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1002    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1003    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1004    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1005    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1006    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1007    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1008    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1009 
1010    You can contact the author at :
1011    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
1012 ****************************************************************** */
1013 #ifndef HUFv07_H_298734234
1014 #define HUFv07_H_298734234
1015 
1016 #if defined (__cplusplus)
1017 extern "C" {
1018 #endif
1019 
1020 
1021 
1022 /* *** simple functions *** */
1023 /**
1024 HUFv07_decompress() :
1025     Decompress HUF data from buffer 'cSrc', of size 'cSrcSize',
1026     into already allocated buffer 'dst', of minimum size 'dstSize'.
1027     `dstSize` : **must** be the ***exact*** size of original (uncompressed) data.
1028     Note : in contrast with FSE, HUFv07_decompress can regenerate
1029            RLE (cSrcSize==1) and uncompressed (cSrcSize==dstSize) data,
1030            because it knows size to regenerate.
1031     @return : size of regenerated data (== dstSize),
1032               or an error code, which can be tested using HUFv07_isError()
1033 */
1034 size_t HUFv07_decompress(void* dst,  size_t dstSize,
1035                 const void* cSrc, size_t cSrcSize);
1036 
1037 
1038 /* ****************************************
1039 *  Tool functions
1040 ******************************************/
1041 #define HUFv07_BLOCKSIZE_MAX (128 * 1024)
1042 
1043 /* Error Management */
1044 unsigned    HUFv07_isError(size_t code);        /**< tells if a return value is an error code */
1045 const char* HUFv07_getErrorName(size_t code);   /**< provides error code string (useful for debugging) */
1046 
1047 
1048 /* *** Advanced function *** */
1049 
1050 
1051 #ifdef HUFv07_STATIC_LINKING_ONLY
1052 
1053 
1054 /* *** Constants *** */
1055 #define HUFv07_TABLELOG_ABSOLUTEMAX  16   /* absolute limit of HUFv07_MAX_TABLELOG. Beyond that value, code does not work */
1056 #define HUFv07_TABLELOG_MAX  12           /* max configured tableLog (for static allocation); can be modified up to HUFv07_ABSOLUTEMAX_TABLELOG */
1057 #define HUFv07_TABLELOG_DEFAULT  11       /* tableLog by default, when not specified */
1058 #define HUFv07_SYMBOLVALUE_MAX 255
1059 #if (HUFv07_TABLELOG_MAX > HUFv07_TABLELOG_ABSOLUTEMAX)
1060 #  error "HUFv07_TABLELOG_MAX is too large !"
1061 #endif
1062 
1063 
1064 /* ****************************************
1065 *  Static allocation
1066 ******************************************/
1067 /* HUF buffer bounds */
1068 #define HUFv07_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
1069 
1070 /* static allocation of HUF's DTable */
1071 typedef U32 HUFv07_DTable;
1072 #define HUFv07_DTABLE_SIZE(maxTableLog)   (1 + (1<<(maxTableLog)))
1073 #define HUFv07_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
1074         HUFv07_DTable DTable[HUFv07_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1)*0x1000001) }
1075 #define HUFv07_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
1076         HUFv07_DTable DTable[HUFv07_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog)*0x1000001) }
1077 
1078 
1079 /* ****************************************
1080 *  Advanced decompression functions
1081 ******************************************/
1082 size_t HUFv07_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
1083 size_t HUFv07_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
1084 
1085 size_t HUFv07_decompress4X_DCtx (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< decodes RLE and uncompressed */
1086 size_t HUFv07_decompress4X_hufOnly(HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< considers RLE and uncompressed as errors */
1087 size_t HUFv07_decompress4X2_DCtx(HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
1088 size_t HUFv07_decompress4X4_DCtx(HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
1089 
1090 size_t HUFv07_decompress1X_DCtx (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
1091 size_t HUFv07_decompress1X2_DCtx(HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
1092 size_t HUFv07_decompress1X4_DCtx(HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
1093 
1094 
1095 /* ****************************************
1096 *  HUF detailed API
1097 ******************************************/
1098 /*!
1099 The following API allows targeting specific sub-functions for advanced tasks.
1100 For example, it's possible to compress several blocks using the same 'CTable',
1101 or to save and regenerate 'CTable' using external methods.
1102 */
1103 /* FSEv07_count() : find it within "fse.h" */
1104 
1105 /*! HUFv07_readStats() :
1106     Read compact Huffman tree, saved by HUFv07_writeCTable().
1107     `huffWeight` is destination buffer.
1108     @return : size read from `src` , or an error Code .
1109     Note : Needed by HUFv07_readCTable() and HUFv07_readDTableXn() . */
1110 size_t HUFv07_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
1111                      U32* nbSymbolsPtr, U32* tableLogPtr,
1112                      const void* src, size_t srcSize);
1113 
1114 
1115 /*
1116 HUFv07_decompress() does the following:
1117 1. select the decompression algorithm (X2, X4) based on pre-computed heuristics
1118 2. build Huffman table from save, using HUFv07_readDTableXn()
1119 3. decode 1 or 4 segments in parallel using HUFv07_decompressSXn_usingDTable
1120 */
1121 
1122 /** HUFv07_selectDecoder() :
1123 *   Tells which decoder is likely to decode faster,
1124 *   based on a set of pre-determined metrics.
1125 *   @return : 0==HUFv07_decompress4X2, 1==HUFv07_decompress4X4 .
1126 *   Assumption : 0 < cSrcSize < dstSize <= 128 KB */
1127 U32 HUFv07_selectDecoder (size_t dstSize, size_t cSrcSize);
1128 
1129 size_t HUFv07_readDTableX2 (HUFv07_DTable* DTable, const void* src, size_t srcSize);
1130 size_t HUFv07_readDTableX4 (HUFv07_DTable* DTable, const void* src, size_t srcSize);
1131 
1132 size_t HUFv07_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUFv07_DTable* DTable);
1133 size_t HUFv07_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUFv07_DTable* DTable);
1134 size_t HUFv07_decompress4X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUFv07_DTable* DTable);
1135 
1136 
1137 /* single stream variants */
1138 size_t HUFv07_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
1139 size_t HUFv07_decompress1X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbol decoder */
1140 
1141 size_t HUFv07_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUFv07_DTable* DTable);
1142 size_t HUFv07_decompress1X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUFv07_DTable* DTable);
1143 size_t HUFv07_decompress1X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUFv07_DTable* DTable);
1144 
1145 
1146 #endif /* HUFv07_STATIC_LINKING_ONLY */
1147 
1148 
1149 #if defined (__cplusplus)
1150 }
1151 #endif
1152 
1153 #endif   /* HUFv07_H_298734234 */
1154 /*
1155    Common functions of New Generation Entropy library
1156    Copyright (C) 2016, Yann Collet.
1157 
1158    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1159 
1160    Redistribution and use in source and binary forms, with or without
1161    modification, are permitted provided that the following conditions are
1162    met:
1163 
1164        * Redistributions of source code must retain the above copyright
1165    notice, this list of conditions and the following disclaimer.
1166        * Redistributions in binary form must reproduce the above
1167    copyright notice, this list of conditions and the following disclaimer
1168    in the documentation and/or other materials provided with the
1169    distribution.
1170 
1171    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1172    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1173    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1174    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1175    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1176    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1177    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1178    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1179    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1180    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1181    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1182 
1183     You can contact the author at :
1184     - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
1185     - Public forum : https://groups.google.com/forum/#!forum/lz4c
1186 *************************************************************************** */
1187 
1188 
1189 
1190 /*-****************************************
1191 *  FSE Error Management
1192 ******************************************/
1193 unsigned FSEv07_isError(size_t code) { return ERR_isError(code); }
1194 
1195 const char* FSEv07_getErrorName(size_t code) { return ERR_getErrorName(code); }
1196 
1197 
1198 /* **************************************************************
1199 *  HUF Error Management
1200 ****************************************************************/
1201 unsigned HUFv07_isError(size_t code) { return ERR_isError(code); }
1202 
1203 const char* HUFv07_getErrorName(size_t code) { return ERR_getErrorName(code); }
1204 
1205 
1206 /*-**************************************************************
1207 *  FSE NCount encoding-decoding
1208 ****************************************************************/
1209 static short FSEv07_abs(short a) { return (short)(a<0 ? -a : a); }
1210 
1211 size_t FSEv07_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
1212                  const void* headerBuffer, size_t hbSize)
1213 {
1214     const BYTE* const istart = (const BYTE*) headerBuffer;
1215     const BYTE* const iend = istart + hbSize;
1216     const BYTE* ip = istart;
1217     int nbBits;
1218     int remaining;
1219     int threshold;
1220     U32 bitStream;
1221     int bitCount;
1222     unsigned charnum = 0;
1223     int previous0 = 0;
1224 
1225     if (hbSize < 4) return ERROR(srcSize_wrong);
1226     bitStream = MEM_readLE32(ip);
1227     nbBits = (bitStream & 0xF) + FSEv07_MIN_TABLELOG;   /* extract tableLog */
1228     if (nbBits > FSEv07_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
1229     bitStream >>= 4;
1230     bitCount = 4;
1231     *tableLogPtr = nbBits;
1232     remaining = (1<<nbBits)+1;
1233     threshold = 1<<nbBits;
1234     nbBits++;
1235 
1236     while ((remaining>1) && (charnum<=*maxSVPtr)) {
1237         if (previous0) {
1238             unsigned n0 = charnum;
1239             while ((bitStream & 0xFFFF) == 0xFFFF) {
1240                 n0+=24;
1241                 if (ip < iend-5) {
1242                     ip+=2;
1243                     bitStream = MEM_readLE32(ip) >> bitCount;
1244                 } else {
1245                     bitStream >>= 16;
1246                     bitCount+=16;
1247             }   }
1248             while ((bitStream & 3) == 3) {
1249                 n0+=3;
1250                 bitStream>>=2;
1251                 bitCount+=2;
1252             }
1253             n0 += bitStream & 3;
1254             bitCount += 2;
1255             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
1256             while (charnum < n0) normalizedCounter[charnum++] = 0;
1257             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
1258                 ip += bitCount>>3;
1259                 bitCount &= 7;
1260                 bitStream = MEM_readLE32(ip) >> bitCount;
1261             }
1262             else
1263                 bitStream >>= 2;
1264         }
1265         {   short const max = (short)((2*threshold-1)-remaining);
1266             short count;
1267 
1268             if ((bitStream & (threshold-1)) < (U32)max) {
1269                 count = (short)(bitStream & (threshold-1));
1270                 bitCount   += nbBits-1;
1271             } else {
1272                 count = (short)(bitStream & (2*threshold-1));
1273                 if (count >= threshold) count -= max;
1274                 bitCount   += nbBits;
1275             }
1276 
1277             count--;   /* extra accuracy */
1278             remaining -= FSEv07_abs(count);
1279             normalizedCounter[charnum++] = count;
1280             previous0 = !count;
1281             while (remaining < threshold) {
1282                 nbBits--;
1283                 threshold >>= 1;
1284             }
1285 
1286             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
1287                 ip += bitCount>>3;
1288                 bitCount &= 7;
1289             } else {
1290                 bitCount -= (int)(8 * (iend - 4 - ip));
1291                 ip = iend - 4;
1292             }
1293             bitStream = MEM_readLE32(ip) >> (bitCount & 31);
1294     }   }   /* while ((remaining>1) && (charnum<=*maxSVPtr)) */
1295     if (remaining != 1) return ERROR(GENERIC);
1296     *maxSVPtr = charnum-1;
1297 
1298     ip += (bitCount+7)>>3;
1299     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
1300     return ip-istart;
1301 }
1302 
1303 
1304 /*! HUFv07_readStats() :
1305     Read compact Huffman tree, saved by HUFv07_writeCTable().
1306     `huffWeight` is destination buffer.
1307     @return : size read from `src` , or an error Code .
1308     Note : Needed by HUFv07_readCTable() and HUFv07_readDTableXn() .
1309 */
1310 size_t HUFv07_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
1311                      U32* nbSymbolsPtr, U32* tableLogPtr,
1312                      const void* src, size_t srcSize)
1313 {
1314     U32 weightTotal;
1315     const BYTE* ip = (const BYTE*) src;
1316     size_t iSize;
1317     size_t oSize;
1318 
1319     if (!srcSize) return ERROR(srcSize_wrong);
1320     iSize = ip[0];
1321     /* memset(huffWeight, 0, hwSize); */   /* is not necessary, even though some analyzer complain ... */
1322 
1323     if (iSize >= 128)  { /* special header */
1324         if (iSize >= (242)) {  /* RLE */
1325             static U32 l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
1326             oSize = l[iSize-242];
1327             memset(huffWeight, 1, hwSize);
1328             iSize = 0;
1329         }
1330         else {   /* Incompressible */
1331             oSize = iSize - 127;
1332             iSize = ((oSize+1)/2);
1333             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1334             if (oSize >= hwSize) return ERROR(corruption_detected);
1335             ip += 1;
1336             {   U32 n;
1337                 for (n=0; n<oSize; n+=2) {
1338                     huffWeight[n]   = ip[n/2] >> 4;
1339                     huffWeight[n+1] = ip[n/2] & 15;
1340     }   }   }   }
1341     else  {   /* header compressed with FSE (normal case) */
1342         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1343         oSize = FSEv07_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
1344         if (FSEv07_isError(oSize)) return oSize;
1345     }
1346 
1347     /* collect weight stats */
1348     memset(rankStats, 0, (HUFv07_TABLELOG_ABSOLUTEMAX + 1) * sizeof(U32));
1349     weightTotal = 0;
1350     {   U32 n; for (n=0; n<oSize; n++) {
1351             if (huffWeight[n] >= HUFv07_TABLELOG_ABSOLUTEMAX) return ERROR(corruption_detected);
1352             rankStats[huffWeight[n]]++;
1353             weightTotal += (1 << huffWeight[n]) >> 1;
1354     }   }
1355     if (weightTotal == 0) return ERROR(corruption_detected);
1356 
1357     /* get last non-null symbol weight (implied, total must be 2^n) */
1358     {   U32 const tableLog = BITv07_highbit32(weightTotal) + 1;
1359         if (tableLog > HUFv07_TABLELOG_ABSOLUTEMAX) return ERROR(corruption_detected);
1360         *tableLogPtr = tableLog;
1361         /* determine last weight */
1362         {   U32 const total = 1 << tableLog;
1363             U32 const rest = total - weightTotal;
1364             U32 const verif = 1 << BITv07_highbit32(rest);
1365             U32 const lastWeight = BITv07_highbit32(rest) + 1;
1366             if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
1367             huffWeight[oSize] = (BYTE)lastWeight;
1368             rankStats[lastWeight]++;
1369     }   }
1370 
1371     /* check tree construction validity */
1372     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
1373 
1374     /* results */
1375     *nbSymbolsPtr = (U32)(oSize+1);
1376     return iSize+1;
1377 }
1378 /* ******************************************************************
1379    FSE : Finite State Entropy decoder
1380    Copyright (C) 2013-2015, Yann Collet.
1381 
1382    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1383 
1384    Redistribution and use in source and binary forms, with or without
1385    modification, are permitted provided that the following conditions are
1386    met:
1387 
1388        * Redistributions of source code must retain the above copyright
1389    notice, this list of conditions and the following disclaimer.
1390        * Redistributions in binary form must reproduce the above
1391    copyright notice, this list of conditions and the following disclaimer
1392    in the documentation and/or other materials provided with the
1393    distribution.
1394 
1395    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1396    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1397    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1398    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1399    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1400    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1401    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1402    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1403    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1404    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1405    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1406 
1407     You can contact the author at :
1408     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
1409     - Public forum : https://groups.google.com/forum/#!forum/lz4c
1410 ****************************************************************** */
1411 
1412 
1413 /* **************************************************************
1414 *  Compiler specifics
1415 ****************************************************************/
1416 #ifdef _MSC_VER    /* Visual Studio */
1417 #  define FORCE_INLINE static __forceinline
1418 #  include <intrin.h>                    /* For Visual 2005 */
1419 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1420 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
1421 #else
1422 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
1423 #    ifdef __GNUC__
1424 #      define FORCE_INLINE static inline __attribute__((always_inline))
1425 #    else
1426 #      define FORCE_INLINE static inline
1427 #    endif
1428 #  else
1429 #    define FORCE_INLINE static
1430 #  endif /* __STDC_VERSION__ */
1431 #endif
1432 
1433 
1434 /* **************************************************************
1435 *  Error Management
1436 ****************************************************************/
1437 #define FSEv07_isError ERR_isError
1438 #define FSEv07_STATIC_ASSERT(c) { enum { FSEv07_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1439 
1440 
1441 /* **************************************************************
1442 *  Complex types
1443 ****************************************************************/
1444 typedef U32 DTable_max_t[FSEv07_DTABLE_SIZE_U32(FSEv07_MAX_TABLELOG)];
1445 
1446 
1447 /* **************************************************************
1448 *  Templates
1449 ****************************************************************/
1450 /*
1451   designed to be included
1452   for type-specific functions (template emulation in C)
1453   Objective is to write these functions only once, for improved maintenance
1454 */
1455 
1456 /* safety checks */
1457 #ifndef FSEv07_FUNCTION_EXTENSION
1458 #  error "FSEv07_FUNCTION_EXTENSION must be defined"
1459 #endif
1460 #ifndef FSEv07_FUNCTION_TYPE
1461 #  error "FSEv07_FUNCTION_TYPE must be defined"
1462 #endif
1463 
1464 /* Function names */
1465 #define FSEv07_CAT(X,Y) X##Y
1466 #define FSEv07_FUNCTION_NAME(X,Y) FSEv07_CAT(X,Y)
1467 #define FSEv07_TYPE_NAME(X,Y) FSEv07_CAT(X,Y)
1468 
1469 
1470 /* Function templates */
1471 FSEv07_DTable* FSEv07_createDTable (unsigned tableLog)
1472 {
1473     if (tableLog > FSEv07_TABLELOG_ABSOLUTE_MAX) tableLog = FSEv07_TABLELOG_ABSOLUTE_MAX;
1474     return (FSEv07_DTable*)malloc( FSEv07_DTABLE_SIZE_U32(tableLog) * sizeof (U32) );
1475 }
1476 
1477 void FSEv07_freeDTable (FSEv07_DTable* dt)
1478 {
1479     free(dt);
1480 }
1481 
1482 size_t FSEv07_buildDTable(FSEv07_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
1483 {
1484     void* const tdPtr = dt+1;   /* because *dt is unsigned, 32-bits aligned on 32-bits */
1485     FSEv07_DECODE_TYPE* const tableDecode = (FSEv07_DECODE_TYPE*) (tdPtr);
1486     U16 symbolNext[FSEv07_MAX_SYMBOL_VALUE+1];
1487 
1488     U32 const maxSV1 = maxSymbolValue + 1;
1489     U32 const tableSize = 1 << tableLog;
1490     U32 highThreshold = tableSize-1;
1491 
1492     /* Sanity Checks */
1493     if (maxSymbolValue > FSEv07_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
1494     if (tableLog > FSEv07_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
1495 
1496     /* Init, lay down lowprob symbols */
1497     {   FSEv07_DTableHeader DTableH;
1498         DTableH.tableLog = (U16)tableLog;
1499         DTableH.fastMode = 1;
1500         {   S16 const largeLimit= (S16)(1 << (tableLog-1));
1501             U32 s;
1502             for (s=0; s<maxSV1; s++) {
1503                 if (normalizedCounter[s]==-1) {
1504                     tableDecode[highThreshold--].symbol = (FSEv07_FUNCTION_TYPE)s;
1505                     symbolNext[s] = 1;
1506                 } else {
1507                     if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
1508                     symbolNext[s] = normalizedCounter[s];
1509         }   }   }
1510         memcpy(dt, &DTableH, sizeof(DTableH));
1511     }
1512 
1513     /* Spread symbols */
1514     {   U32 const tableMask = tableSize-1;
1515         U32 const step = FSEv07_TABLESTEP(tableSize);
1516         U32 s, position = 0;
1517         for (s=0; s<maxSV1; s++) {
1518             int i;
1519             for (i=0; i<normalizedCounter[s]; i++) {
1520                 tableDecode[position].symbol = (FSEv07_FUNCTION_TYPE)s;
1521                 position = (position + step) & tableMask;
1522                 while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
1523         }   }
1524 
1525         if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
1526     }
1527 
1528     /* Build Decoding table */
1529     {   U32 u;
1530         for (u=0; u<tableSize; u++) {
1531             FSEv07_FUNCTION_TYPE const symbol = (FSEv07_FUNCTION_TYPE)(tableDecode[u].symbol);
1532             U16 nextState = symbolNext[symbol]++;
1533             tableDecode[u].nbBits = (BYTE) (tableLog - BITv07_highbit32 ((U32)nextState) );
1534             tableDecode[u].newState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
1535     }   }
1536 
1537     return 0;
1538 }
1539 
1540 
1541 
1542 #ifndef FSEv07_COMMONDEFS_ONLY
1543 
1544 /*-*******************************************************
1545 *  Decompression (Byte symbols)
1546 *********************************************************/
1547 size_t FSEv07_buildDTable_rle (FSEv07_DTable* dt, BYTE symbolValue)
1548 {
1549     void* ptr = dt;
1550     FSEv07_DTableHeader* const DTableH = (FSEv07_DTableHeader*)ptr;
1551     void* dPtr = dt + 1;
1552     FSEv07_decode_t* const cell = (FSEv07_decode_t*)dPtr;
1553 
1554     DTableH->tableLog = 0;
1555     DTableH->fastMode = 0;
1556 
1557     cell->newState = 0;
1558     cell->symbol = symbolValue;
1559     cell->nbBits = 0;
1560 
1561     return 0;
1562 }
1563 
1564 
1565 size_t FSEv07_buildDTable_raw (FSEv07_DTable* dt, unsigned nbBits)
1566 {
1567     void* ptr = dt;
1568     FSEv07_DTableHeader* const DTableH = (FSEv07_DTableHeader*)ptr;
1569     void* dPtr = dt + 1;
1570     FSEv07_decode_t* const dinfo = (FSEv07_decode_t*)dPtr;
1571     const unsigned tableSize = 1 << nbBits;
1572     const unsigned tableMask = tableSize - 1;
1573     const unsigned maxSV1 = tableMask+1;
1574     unsigned s;
1575 
1576     /* Sanity checks */
1577     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
1578 
1579     /* Build Decoding Table */
1580     DTableH->tableLog = (U16)nbBits;
1581     DTableH->fastMode = 1;
1582     for (s=0; s<maxSV1; s++) {
1583         dinfo[s].newState = 0;
1584         dinfo[s].symbol = (BYTE)s;
1585         dinfo[s].nbBits = (BYTE)nbBits;
1586     }
1587 
1588     return 0;
1589 }
1590 
1591 FORCE_INLINE size_t FSEv07_decompress_usingDTable_generic(
1592           void* dst, size_t maxDstSize,
1593     const void* cSrc, size_t cSrcSize,
1594     const FSEv07_DTable* dt, const unsigned fast)
1595 {
1596     BYTE* const ostart = (BYTE*) dst;
1597     BYTE* op = ostart;
1598     BYTE* const omax = op + maxDstSize;
1599     BYTE* const olimit = omax-3;
1600 
1601     BITv07_DStream_t bitD;
1602     FSEv07_DState_t state1;
1603     FSEv07_DState_t state2;
1604 
1605     /* Init */
1606     { size_t const errorCode = BITv07_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
1607       if (FSEv07_isError(errorCode)) return errorCode; }
1608 
1609     FSEv07_initDState(&state1, &bitD, dt);
1610     FSEv07_initDState(&state2, &bitD, dt);
1611 
1612 #define FSEv07_GETSYMBOL(statePtr) fast ? FSEv07_decodeSymbolFast(statePtr, &bitD) : FSEv07_decodeSymbol(statePtr, &bitD)
1613 
1614     /* 4 symbols per loop */
1615     for ( ; (BITv07_reloadDStream(&bitD)==BITv07_DStream_unfinished) && (op<olimit) ; op+=4) {
1616         op[0] = FSEv07_GETSYMBOL(&state1);
1617 
1618         if (FSEv07_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1619             BITv07_reloadDStream(&bitD);
1620 
1621         op[1] = FSEv07_GETSYMBOL(&state2);
1622 
1623         if (FSEv07_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1624             { if (BITv07_reloadDStream(&bitD) > BITv07_DStream_unfinished) { op+=2; break; } }
1625 
1626         op[2] = FSEv07_GETSYMBOL(&state1);
1627 
1628         if (FSEv07_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1629             BITv07_reloadDStream(&bitD);
1630 
1631         op[3] = FSEv07_GETSYMBOL(&state2);
1632     }
1633 
1634     /* tail */
1635     /* note : BITv07_reloadDStream(&bitD) >= FSEv07_DStream_partiallyFilled; Ends at exactly BITv07_DStream_completed */
1636     while (1) {
1637         if (op>(omax-2)) return ERROR(dstSize_tooSmall);
1638 
1639         *op++ = FSEv07_GETSYMBOL(&state1);
1640 
1641         if (BITv07_reloadDStream(&bitD)==BITv07_DStream_overflow) {
1642             *op++ = FSEv07_GETSYMBOL(&state2);
1643             break;
1644         }
1645 
1646         if (op>(omax-2)) return ERROR(dstSize_tooSmall);
1647 
1648         *op++ = FSEv07_GETSYMBOL(&state2);
1649 
1650         if (BITv07_reloadDStream(&bitD)==BITv07_DStream_overflow) {
1651             *op++ = FSEv07_GETSYMBOL(&state1);
1652             break;
1653     }   }
1654 
1655     return op-ostart;
1656 }
1657 
1658 
1659 size_t FSEv07_decompress_usingDTable(void* dst, size_t originalSize,
1660                             const void* cSrc, size_t cSrcSize,
1661                             const FSEv07_DTable* dt)
1662 {
1663     const void* ptr = dt;
1664     const FSEv07_DTableHeader* DTableH = (const FSEv07_DTableHeader*)ptr;
1665     const U32 fastMode = DTableH->fastMode;
1666 
1667     /* select fast mode (static) */
1668     if (fastMode) return FSEv07_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
1669     return FSEv07_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
1670 }
1671 
1672 
1673 size_t FSEv07_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
1674 {
1675     const BYTE* const istart = (const BYTE*)cSrc;
1676     const BYTE* ip = istart;
1677     short counting[FSEv07_MAX_SYMBOL_VALUE+1];
1678     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
1679     unsigned tableLog;
1680     unsigned maxSymbolValue = FSEv07_MAX_SYMBOL_VALUE;
1681 
1682     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
1683 
1684     /* normal FSE decoding mode */
1685     {   size_t const NCountLength = FSEv07_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
1686         if (FSEv07_isError(NCountLength)) return NCountLength;
1687         if (NCountLength >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
1688         ip += NCountLength;
1689         cSrcSize -= NCountLength;
1690     }
1691 
1692     { size_t const errorCode = FSEv07_buildDTable (dt, counting, maxSymbolValue, tableLog);
1693       if (FSEv07_isError(errorCode)) return errorCode; }
1694 
1695     return FSEv07_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);   /* always return, even if it is an error code */
1696 }
1697 
1698 
1699 
1700 #endif   /* FSEv07_COMMONDEFS_ONLY */
1701 
1702 /* ******************************************************************
1703    Huffman decoder, part of New Generation Entropy library
1704    Copyright (C) 2013-2016, Yann Collet.
1705 
1706    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1707 
1708    Redistribution and use in source and binary forms, with or without
1709    modification, are permitted provided that the following conditions are
1710    met:
1711 
1712        * Redistributions of source code must retain the above copyright
1713    notice, this list of conditions and the following disclaimer.
1714        * Redistributions in binary form must reproduce the above
1715    copyright notice, this list of conditions and the following disclaimer
1716    in the documentation and/or other materials provided with the
1717    distribution.
1718 
1719    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1720    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1721    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1722    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1723    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1724    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1725    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1726    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1727    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1728    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1729    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1730 
1731     You can contact the author at :
1732     - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
1733     - Public forum : https://groups.google.com/forum/#!forum/lz4c
1734 ****************************************************************** */
1735 
1736 /* **************************************************************
1737 *  Compiler specifics
1738 ****************************************************************/
1739 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
1740 /* inline is defined */
1741 #elif defined(_MSC_VER)
1742 #  define inline __inline
1743 #else
1744 #  define inline /* disable inline */
1745 #endif
1746 
1747 
1748 #ifdef _MSC_VER    /* Visual Studio */
1749 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1750 #endif
1751 
1752 
1753 
1754 /* **************************************************************
1755 *  Error Management
1756 ****************************************************************/
1757 #define HUFv07_STATIC_ASSERT(c) { enum { HUFv07_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1758 
1759 
1760 /*-***************************/
1761 /*  generic DTableDesc       */
1762 /*-***************************/
1763 
1764 typedef struct { BYTE maxTableLog; BYTE tableType; BYTE tableLog; BYTE reserved; } DTableDesc;
1765 
1766 static DTableDesc HUFv07_getDTableDesc(const HUFv07_DTable* table)
1767 {
1768     DTableDesc dtd;
1769     memcpy(&dtd, table, sizeof(dtd));
1770     return dtd;
1771 }
1772 
1773 
1774 /*-***************************/
1775 /*  single-symbol decoding   */
1776 /*-***************************/
1777 
1778 typedef struct { BYTE byte; BYTE nbBits; } HUFv07_DEltX2;   /* single-symbol decoding */
1779 
1780 size_t HUFv07_readDTableX2 (HUFv07_DTable* DTable, const void* src, size_t srcSize)
1781 {
1782     BYTE huffWeight[HUFv07_SYMBOLVALUE_MAX + 1];
1783     U32 rankVal[HUFv07_TABLELOG_ABSOLUTEMAX + 1];   /* large enough for values from 0 to 16 */
1784     U32 tableLog = 0;
1785     U32 nbSymbols = 0;
1786     size_t iSize;
1787     void* const dtPtr = DTable + 1;
1788     HUFv07_DEltX2* const dt = (HUFv07_DEltX2*)dtPtr;
1789 
1790     HUFv07_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUFv07_DTable));
1791     /* memset(huffWeight, 0, sizeof(huffWeight)); */   /* is not necessary, even though some analyzer complain ... */
1792 
1793     iSize = HUFv07_readStats(huffWeight, HUFv07_SYMBOLVALUE_MAX + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
1794     if (HUFv07_isError(iSize)) return iSize;
1795 
1796     /* Table header */
1797     {   DTableDesc dtd = HUFv07_getDTableDesc(DTable);
1798         if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge);   /* DTable too small, huffman tree cannot fit in */
1799         dtd.tableType = 0;
1800         dtd.tableLog = (BYTE)tableLog;
1801         memcpy(DTable, &dtd, sizeof(dtd));
1802     }
1803 
1804     /* Prepare ranks */
1805     {   U32 n, nextRankStart = 0;
1806         for (n=1; n<tableLog+1; n++) {
1807             U32 current = nextRankStart;
1808             nextRankStart += (rankVal[n] << (n-1));
1809             rankVal[n] = current;
1810     }   }
1811 
1812     /* fill DTable */
1813     {   U32 n;
1814         for (n=0; n<nbSymbols; n++) {
1815             U32 const w = huffWeight[n];
1816             U32 const length = (1 << w) >> 1;
1817             U32 i;
1818             HUFv07_DEltX2 D;
1819             D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
1820             for (i = rankVal[w]; i < rankVal[w] + length; i++)
1821                 dt[i] = D;
1822             rankVal[w] += length;
1823     }   }
1824 
1825     return iSize;
1826 }
1827 
1828 
1829 static BYTE HUFv07_decodeSymbolX2(BITv07_DStream_t* Dstream, const HUFv07_DEltX2* dt, const U32 dtLog)
1830 {
1831     size_t const val = BITv07_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
1832     BYTE const c = dt[val].byte;
1833     BITv07_skipBits(Dstream, dt[val].nbBits);
1834     return c;
1835 }
1836 
1837 #define HUFv07_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
1838     *ptr++ = HUFv07_decodeSymbolX2(DStreamPtr, dt, dtLog)
1839 
1840 #define HUFv07_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
1841     if (MEM_64bits() || (HUFv07_TABLELOG_MAX<=12)) \
1842         HUFv07_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1843 
1844 #define HUFv07_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
1845     if (MEM_64bits()) \
1846         HUFv07_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1847 
1848 static inline size_t HUFv07_decodeStreamX2(BYTE* p, BITv07_DStream_t* const bitDPtr, BYTE* const pEnd, const HUFv07_DEltX2* const dt, const U32 dtLog)
1849 {
1850     BYTE* const pStart = p;
1851 
1852     /* up to 4 symbols at a time */
1853     while ((BITv07_reloadDStream(bitDPtr) == BITv07_DStream_unfinished) && (p <= pEnd-4)) {
1854         HUFv07_DECODE_SYMBOLX2_2(p, bitDPtr);
1855         HUFv07_DECODE_SYMBOLX2_1(p, bitDPtr);
1856         HUFv07_DECODE_SYMBOLX2_2(p, bitDPtr);
1857         HUFv07_DECODE_SYMBOLX2_0(p, bitDPtr);
1858     }
1859 
1860     /* closer to the end */
1861     while ((BITv07_reloadDStream(bitDPtr) == BITv07_DStream_unfinished) && (p < pEnd))
1862         HUFv07_DECODE_SYMBOLX2_0(p, bitDPtr);
1863 
1864     /* no more data to retrieve from bitstream, hence no need to reload */
1865     while (p < pEnd)
1866         HUFv07_DECODE_SYMBOLX2_0(p, bitDPtr);
1867 
1868     return pEnd-pStart;
1869 }
1870 
1871 static size_t HUFv07_decompress1X2_usingDTable_internal(
1872           void* dst,  size_t dstSize,
1873     const void* cSrc, size_t cSrcSize,
1874     const HUFv07_DTable* DTable)
1875 {
1876     BYTE* op = (BYTE*)dst;
1877     BYTE* const oend = op + dstSize;
1878     const void* dtPtr = DTable + 1;
1879     const HUFv07_DEltX2* const dt = (const HUFv07_DEltX2*)dtPtr;
1880     BITv07_DStream_t bitD;
1881     DTableDesc const dtd = HUFv07_getDTableDesc(DTable);
1882     U32 const dtLog = dtd.tableLog;
1883 
1884     { size_t const errorCode = BITv07_initDStream(&bitD, cSrc, cSrcSize);
1885       if (HUFv07_isError(errorCode)) return errorCode; }
1886 
1887     HUFv07_decodeStreamX2(op, &bitD, oend, dt, dtLog);
1888 
1889     /* check */
1890     if (!BITv07_endOfDStream(&bitD)) return ERROR(corruption_detected);
1891 
1892     return dstSize;
1893 }
1894 
1895 size_t HUFv07_decompress1X2_usingDTable(
1896           void* dst,  size_t dstSize,
1897     const void* cSrc, size_t cSrcSize,
1898     const HUFv07_DTable* DTable)
1899 {
1900     DTableDesc dtd = HUFv07_getDTableDesc(DTable);
1901     if (dtd.tableType != 0) return ERROR(GENERIC);
1902     return HUFv07_decompress1X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable);
1903 }
1904 
1905 size_t HUFv07_decompress1X2_DCtx (HUFv07_DTable* DCtx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
1906 {
1907     const BYTE* ip = (const BYTE*) cSrc;
1908 
1909     size_t const hSize = HUFv07_readDTableX2 (DCtx, cSrc, cSrcSize);
1910     if (HUFv07_isError(hSize)) return hSize;
1911     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
1912     ip += hSize; cSrcSize -= hSize;
1913 
1914     return HUFv07_decompress1X2_usingDTable_internal (dst, dstSize, ip, cSrcSize, DCtx);
1915 }
1916 
1917 size_t HUFv07_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
1918 {
1919     HUFv07_CREATE_STATIC_DTABLEX2(DTable, HUFv07_TABLELOG_MAX);
1920     return HUFv07_decompress1X2_DCtx (DTable, dst, dstSize, cSrc, cSrcSize);
1921 }
1922 
1923 
1924 static size_t HUFv07_decompress4X2_usingDTable_internal(
1925           void* dst,  size_t dstSize,
1926     const void* cSrc, size_t cSrcSize,
1927     const HUFv07_DTable* DTable)
1928 {
1929     /* Check */
1930     if (cSrcSize < 10) return ERROR(corruption_detected);  /* strict minimum : jump table + 1 byte per stream */
1931 
1932     {   const BYTE* const istart = (const BYTE*) cSrc;
1933         BYTE* const ostart = (BYTE*) dst;
1934         BYTE* const oend = ostart + dstSize;
1935         const void* const dtPtr = DTable + 1;
1936         const HUFv07_DEltX2* const dt = (const HUFv07_DEltX2*)dtPtr;
1937 
1938         /* Init */
1939         BITv07_DStream_t bitD1;
1940         BITv07_DStream_t bitD2;
1941         BITv07_DStream_t bitD3;
1942         BITv07_DStream_t bitD4;
1943         size_t const length1 = MEM_readLE16(istart);
1944         size_t const length2 = MEM_readLE16(istart+2);
1945         size_t const length3 = MEM_readLE16(istart+4);
1946         size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
1947         const BYTE* const istart1 = istart + 6;  /* jumpTable */
1948         const BYTE* const istart2 = istart1 + length1;
1949         const BYTE* const istart3 = istart2 + length2;
1950         const BYTE* const istart4 = istart3 + length3;
1951         const size_t segmentSize = (dstSize+3) / 4;
1952         BYTE* const opStart2 = ostart + segmentSize;
1953         BYTE* const opStart3 = opStart2 + segmentSize;
1954         BYTE* const opStart4 = opStart3 + segmentSize;
1955         BYTE* op1 = ostart;
1956         BYTE* op2 = opStart2;
1957         BYTE* op3 = opStart3;
1958         BYTE* op4 = opStart4;
1959         U32 endSignal;
1960         DTableDesc const dtd = HUFv07_getDTableDesc(DTable);
1961         U32 const dtLog = dtd.tableLog;
1962 
1963         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
1964         { size_t const errorCode = BITv07_initDStream(&bitD1, istart1, length1);
1965           if (HUFv07_isError(errorCode)) return errorCode; }
1966         { size_t const errorCode = BITv07_initDStream(&bitD2, istart2, length2);
1967           if (HUFv07_isError(errorCode)) return errorCode; }
1968         { size_t const errorCode = BITv07_initDStream(&bitD3, istart3, length3);
1969           if (HUFv07_isError(errorCode)) return errorCode; }
1970         { size_t const errorCode = BITv07_initDStream(&bitD4, istart4, length4);
1971           if (HUFv07_isError(errorCode)) return errorCode; }
1972 
1973         /* 16-32 symbols per loop (4-8 symbols per stream) */
1974         endSignal = BITv07_reloadDStream(&bitD1) | BITv07_reloadDStream(&bitD2) | BITv07_reloadDStream(&bitD3) | BITv07_reloadDStream(&bitD4);
1975         for ( ; (endSignal==BITv07_DStream_unfinished) && (op4<(oend-7)) ; ) {
1976             HUFv07_DECODE_SYMBOLX2_2(op1, &bitD1);
1977             HUFv07_DECODE_SYMBOLX2_2(op2, &bitD2);
1978             HUFv07_DECODE_SYMBOLX2_2(op3, &bitD3);
1979             HUFv07_DECODE_SYMBOLX2_2(op4, &bitD4);
1980             HUFv07_DECODE_SYMBOLX2_1(op1, &bitD1);
1981             HUFv07_DECODE_SYMBOLX2_1(op2, &bitD2);
1982             HUFv07_DECODE_SYMBOLX2_1(op3, &bitD3);
1983             HUFv07_DECODE_SYMBOLX2_1(op4, &bitD4);
1984             HUFv07_DECODE_SYMBOLX2_2(op1, &bitD1);
1985             HUFv07_DECODE_SYMBOLX2_2(op2, &bitD2);
1986             HUFv07_DECODE_SYMBOLX2_2(op3, &bitD3);
1987             HUFv07_DECODE_SYMBOLX2_2(op4, &bitD4);
1988             HUFv07_DECODE_SYMBOLX2_0(op1, &bitD1);
1989             HUFv07_DECODE_SYMBOLX2_0(op2, &bitD2);
1990             HUFv07_DECODE_SYMBOLX2_0(op3, &bitD3);
1991             HUFv07_DECODE_SYMBOLX2_0(op4, &bitD4);
1992             endSignal = BITv07_reloadDStream(&bitD1) | BITv07_reloadDStream(&bitD2) | BITv07_reloadDStream(&bitD3) | BITv07_reloadDStream(&bitD4);
1993         }
1994 
1995         /* check corruption */
1996         if (op1 > opStart2) return ERROR(corruption_detected);
1997         if (op2 > opStart3) return ERROR(corruption_detected);
1998         if (op3 > opStart4) return ERROR(corruption_detected);
1999         /* note : op4 supposed already verified within main loop */
2000 
2001         /* finish bitStreams one by one */
2002         HUFv07_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
2003         HUFv07_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
2004         HUFv07_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
2005         HUFv07_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
2006 
2007         /* check */
2008         endSignal = BITv07_endOfDStream(&bitD1) & BITv07_endOfDStream(&bitD2) & BITv07_endOfDStream(&bitD3) & BITv07_endOfDStream(&bitD4);
2009         if (!endSignal) return ERROR(corruption_detected);
2010 
2011         /* decoded size */
2012         return dstSize;
2013     }
2014 }
2015 
2016 
2017 size_t HUFv07_decompress4X2_usingDTable(
2018           void* dst,  size_t dstSize,
2019     const void* cSrc, size_t cSrcSize,
2020     const HUFv07_DTable* DTable)
2021 {
2022     DTableDesc dtd = HUFv07_getDTableDesc(DTable);
2023     if (dtd.tableType != 0) return ERROR(GENERIC);
2024     return HUFv07_decompress4X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable);
2025 }
2026 
2027 
2028 size_t HUFv07_decompress4X2_DCtx (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2029 {
2030     const BYTE* ip = (const BYTE*) cSrc;
2031 
2032     size_t const hSize = HUFv07_readDTableX2 (dctx, cSrc, cSrcSize);
2033     if (HUFv07_isError(hSize)) return hSize;
2034     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2035     ip += hSize; cSrcSize -= hSize;
2036 
2037     return HUFv07_decompress4X2_usingDTable_internal (dst, dstSize, ip, cSrcSize, dctx);
2038 }
2039 
2040 size_t HUFv07_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2041 {
2042     HUFv07_CREATE_STATIC_DTABLEX2(DTable, HUFv07_TABLELOG_MAX);
2043     return HUFv07_decompress4X2_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
2044 }
2045 
2046 
2047 /* *************************/
2048 /* double-symbols decoding */
2049 /* *************************/
2050 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUFv07_DEltX4;  /* double-symbols decoding */
2051 
2052 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
2053 
2054 static void HUFv07_fillDTableX4Level2(HUFv07_DEltX4* DTable, U32 sizeLog, const U32 consumed,
2055                            const U32* rankValOrigin, const int minWeight,
2056                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
2057                            U32 nbBitsBaseline, U16 baseSeq)
2058 {
2059     HUFv07_DEltX4 DElt;
2060     U32 rankVal[HUFv07_TABLELOG_ABSOLUTEMAX + 1];
2061 
2062     /* get pre-calculated rankVal */
2063     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
2064 
2065     /* fill skipped values */
2066     if (minWeight>1) {
2067         U32 i, skipSize = rankVal[minWeight];
2068         MEM_writeLE16(&(DElt.sequence), baseSeq);
2069         DElt.nbBits   = (BYTE)(consumed);
2070         DElt.length   = 1;
2071         for (i = 0; i < skipSize; i++)
2072             DTable[i] = DElt;
2073     }
2074 
2075     /* fill DTable */
2076     { U32 s; for (s=0; s<sortedListSize; s++) {   /* note : sortedSymbols already skipped */
2077         const U32 symbol = sortedSymbols[s].symbol;
2078         const U32 weight = sortedSymbols[s].weight;
2079         const U32 nbBits = nbBitsBaseline - weight;
2080         const U32 length = 1 << (sizeLog-nbBits);
2081         const U32 start = rankVal[weight];
2082         U32 i = start;
2083         const U32 end = start + length;
2084 
2085         MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
2086         DElt.nbBits = (BYTE)(nbBits + consumed);
2087         DElt.length = 2;
2088         do { DTable[i++] = DElt; } while (i<end);   /* since length >= 1 */
2089 
2090         rankVal[weight] += length;
2091     }}
2092 }
2093 
2094 typedef U32 rankVal_t[HUFv07_TABLELOG_ABSOLUTEMAX][HUFv07_TABLELOG_ABSOLUTEMAX + 1];
2095 
2096 static void HUFv07_fillDTableX4(HUFv07_DEltX4* DTable, const U32 targetLog,
2097                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
2098                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
2099                            const U32 nbBitsBaseline)
2100 {
2101     U32 rankVal[HUFv07_TABLELOG_ABSOLUTEMAX + 1];
2102     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
2103     const U32 minBits  = nbBitsBaseline - maxWeight;
2104     U32 s;
2105 
2106     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
2107 
2108     /* fill DTable */
2109     for (s=0; s<sortedListSize; s++) {
2110         const U16 symbol = sortedList[s].symbol;
2111         const U32 weight = sortedList[s].weight;
2112         const U32 nbBits = nbBitsBaseline - weight;
2113         const U32 start = rankVal[weight];
2114         const U32 length = 1 << (targetLog-nbBits);
2115 
2116         if (targetLog-nbBits >= minBits) {   /* enough room for a second symbol */
2117             U32 sortedRank;
2118             int minWeight = nbBits + scaleLog;
2119             if (minWeight < 1) minWeight = 1;
2120             sortedRank = rankStart[minWeight];
2121             HUFv07_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
2122                            rankValOrigin[nbBits], minWeight,
2123                            sortedList+sortedRank, sortedListSize-sortedRank,
2124                            nbBitsBaseline, symbol);
2125         } else {
2126             HUFv07_DEltX4 DElt;
2127             MEM_writeLE16(&(DElt.sequence), symbol);
2128             DElt.nbBits = (BYTE)(nbBits);
2129             DElt.length = 1;
2130             {   U32 u;
2131                 const U32 end = start + length;
2132                 for (u = start; u < end; u++) DTable[u] = DElt;
2133         }   }
2134         rankVal[weight] += length;
2135     }
2136 }
2137 
2138 size_t HUFv07_readDTableX4 (HUFv07_DTable* DTable, const void* src, size_t srcSize)
2139 {
2140     BYTE weightList[HUFv07_SYMBOLVALUE_MAX + 1];
2141     sortedSymbol_t sortedSymbol[HUFv07_SYMBOLVALUE_MAX + 1];
2142     U32 rankStats[HUFv07_TABLELOG_ABSOLUTEMAX + 1] = { 0 };
2143     U32 rankStart0[HUFv07_TABLELOG_ABSOLUTEMAX + 2] = { 0 };
2144     U32* const rankStart = rankStart0+1;
2145     rankVal_t rankVal;
2146     U32 tableLog, maxW, sizeOfSort, nbSymbols;
2147     DTableDesc dtd = HUFv07_getDTableDesc(DTable);
2148     U32 const maxTableLog = dtd.maxTableLog;
2149     size_t iSize;
2150     void* dtPtr = DTable+1;   /* force compiler to avoid strict-aliasing */
2151     HUFv07_DEltX4* const dt = (HUFv07_DEltX4*)dtPtr;
2152 
2153     HUFv07_STATIC_ASSERT(sizeof(HUFv07_DEltX4) == sizeof(HUFv07_DTable));   /* if compilation fails here, assertion is false */
2154     if (maxTableLog > HUFv07_TABLELOG_ABSOLUTEMAX) return ERROR(tableLog_tooLarge);
2155     /* memset(weightList, 0, sizeof(weightList)); */   /* is not necessary, even though some analyzer complain ... */
2156 
2157     iSize = HUFv07_readStats(weightList, HUFv07_SYMBOLVALUE_MAX + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
2158     if (HUFv07_isError(iSize)) return iSize;
2159 
2160     /* check result */
2161     if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
2162 
2163     /* find maxWeight */
2164     for (maxW = tableLog; rankStats[maxW]==0; maxW--) {}  /* necessarily finds a solution before 0 */
2165 
2166     /* Get start index of each weight */
2167     {   U32 w, nextRankStart = 0;
2168         for (w=1; w<maxW+1; w++) {
2169             U32 current = nextRankStart;
2170             nextRankStart += rankStats[w];
2171             rankStart[w] = current;
2172         }
2173         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
2174         sizeOfSort = nextRankStart;
2175     }
2176 
2177     /* sort symbols by weight */
2178     {   U32 s;
2179         for (s=0; s<nbSymbols; s++) {
2180             U32 const w = weightList[s];
2181             U32 const r = rankStart[w]++;
2182             sortedSymbol[r].symbol = (BYTE)s;
2183             sortedSymbol[r].weight = (BYTE)w;
2184         }
2185         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
2186     }
2187 
2188     /* Build rankVal */
2189     {   U32* const rankVal0 = rankVal[0];
2190         {   int const rescale = (maxTableLog-tableLog) - 1;   /* tableLog <= maxTableLog */
2191             U32 nextRankVal = 0;
2192             U32 w;
2193             for (w=1; w<maxW+1; w++) {
2194                 U32 current = nextRankVal;
2195                 nextRankVal += rankStats[w] << (w+rescale);
2196                 rankVal0[w] = current;
2197         }   }
2198         {   U32 const minBits = tableLog+1 - maxW;
2199             U32 consumed;
2200             for (consumed = minBits; consumed < maxTableLog - minBits + 1; consumed++) {
2201                 U32* const rankValPtr = rankVal[consumed];
2202                 U32 w;
2203                 for (w = 1; w < maxW+1; w++) {
2204                     rankValPtr[w] = rankVal0[w] >> consumed;
2205     }   }   }   }
2206 
2207     HUFv07_fillDTableX4(dt, maxTableLog,
2208                    sortedSymbol, sizeOfSort,
2209                    rankStart0, rankVal, maxW,
2210                    tableLog+1);
2211 
2212     dtd.tableLog = (BYTE)maxTableLog;
2213     dtd.tableType = 1;
2214     memcpy(DTable, &dtd, sizeof(dtd));
2215     return iSize;
2216 }
2217 
2218 
2219 static U32 HUFv07_decodeSymbolX4(void* op, BITv07_DStream_t* DStream, const HUFv07_DEltX4* dt, const U32 dtLog)
2220 {
2221     const size_t val = BITv07_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2222     memcpy(op, dt+val, 2);
2223     BITv07_skipBits(DStream, dt[val].nbBits);
2224     return dt[val].length;
2225 }
2226 
2227 static U32 HUFv07_decodeLastSymbolX4(void* op, BITv07_DStream_t* DStream, const HUFv07_DEltX4* dt, const U32 dtLog)
2228 {
2229     const size_t val = BITv07_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2230     memcpy(op, dt+val, 1);
2231     if (dt[val].length==1) BITv07_skipBits(DStream, dt[val].nbBits);
2232     else {
2233         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) {
2234             BITv07_skipBits(DStream, dt[val].nbBits);
2235             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2236                 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 */
2237     }   }
2238     return 1;
2239 }
2240 
2241 
2242 #define HUFv07_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
2243     ptr += HUFv07_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2244 
2245 #define HUFv07_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
2246     if (MEM_64bits() || (HUFv07_TABLELOG_MAX<=12)) \
2247         ptr += HUFv07_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2248 
2249 #define HUFv07_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
2250     if (MEM_64bits()) \
2251         ptr += HUFv07_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2252 
2253 static inline size_t HUFv07_decodeStreamX4(BYTE* p, BITv07_DStream_t* bitDPtr, BYTE* const pEnd, const HUFv07_DEltX4* const dt, const U32 dtLog)
2254 {
2255     BYTE* const pStart = p;
2256 
2257     /* up to 8 symbols at a time */
2258     while ((BITv07_reloadDStream(bitDPtr) == BITv07_DStream_unfinished) && (p < pEnd-7)) {
2259         HUFv07_DECODE_SYMBOLX4_2(p, bitDPtr);
2260         HUFv07_DECODE_SYMBOLX4_1(p, bitDPtr);
2261         HUFv07_DECODE_SYMBOLX4_2(p, bitDPtr);
2262         HUFv07_DECODE_SYMBOLX4_0(p, bitDPtr);
2263     }
2264 
2265     /* closer to end : up to 2 symbols at a time */
2266     while ((BITv07_reloadDStream(bitDPtr) == BITv07_DStream_unfinished) && (p <= pEnd-2))
2267         HUFv07_DECODE_SYMBOLX4_0(p, bitDPtr);
2268 
2269     while (p <= pEnd-2)
2270         HUFv07_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2271 
2272     if (p < pEnd)
2273         p += HUFv07_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
2274 
2275     return p-pStart;
2276 }
2277 
2278 
2279 static size_t HUFv07_decompress1X4_usingDTable_internal(
2280           void* dst,  size_t dstSize,
2281     const void* cSrc, size_t cSrcSize,
2282     const HUFv07_DTable* DTable)
2283 {
2284     BITv07_DStream_t bitD;
2285 
2286     /* Init */
2287     {   size_t const errorCode = BITv07_initDStream(&bitD, cSrc, cSrcSize);
2288         if (HUFv07_isError(errorCode)) return errorCode;
2289     }
2290 
2291     /* decode */
2292     {   BYTE* const ostart = (BYTE*) dst;
2293         BYTE* const oend = ostart + dstSize;
2294         const void* const dtPtr = DTable+1;   /* force compiler to not use strict-aliasing */
2295         const HUFv07_DEltX4* const dt = (const HUFv07_DEltX4*)dtPtr;
2296         DTableDesc const dtd = HUFv07_getDTableDesc(DTable);
2297         HUFv07_decodeStreamX4(ostart, &bitD, oend, dt, dtd.tableLog);
2298     }
2299 
2300     /* check */
2301     if (!BITv07_endOfDStream(&bitD)) return ERROR(corruption_detected);
2302 
2303     /* decoded size */
2304     return dstSize;
2305 }
2306 
2307 size_t HUFv07_decompress1X4_usingDTable(
2308           void* dst,  size_t dstSize,
2309     const void* cSrc, size_t cSrcSize,
2310     const HUFv07_DTable* DTable)
2311 {
2312     DTableDesc dtd = HUFv07_getDTableDesc(DTable);
2313     if (dtd.tableType != 1) return ERROR(GENERIC);
2314     return HUFv07_decompress1X4_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable);
2315 }
2316 
2317 size_t HUFv07_decompress1X4_DCtx (HUFv07_DTable* DCtx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2318 {
2319     const BYTE* ip = (const BYTE*) cSrc;
2320 
2321     size_t const hSize = HUFv07_readDTableX4 (DCtx, cSrc, cSrcSize);
2322     if (HUFv07_isError(hSize)) return hSize;
2323     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2324     ip += hSize; cSrcSize -= hSize;
2325 
2326     return HUFv07_decompress1X4_usingDTable_internal (dst, dstSize, ip, cSrcSize, DCtx);
2327 }
2328 
2329 size_t HUFv07_decompress1X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2330 {
2331     HUFv07_CREATE_STATIC_DTABLEX4(DTable, HUFv07_TABLELOG_MAX);
2332     return HUFv07_decompress1X4_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
2333 }
2334 
2335 static size_t HUFv07_decompress4X4_usingDTable_internal(
2336           void* dst,  size_t dstSize,
2337     const void* cSrc, size_t cSrcSize,
2338     const HUFv07_DTable* DTable)
2339 {
2340     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2341 
2342     {   const BYTE* const istart = (const BYTE*) cSrc;
2343         BYTE* const ostart = (BYTE*) dst;
2344         BYTE* const oend = ostart + dstSize;
2345         const void* const dtPtr = DTable+1;
2346         const HUFv07_DEltX4* const dt = (const HUFv07_DEltX4*)dtPtr;
2347 
2348         /* Init */
2349         BITv07_DStream_t bitD1;
2350         BITv07_DStream_t bitD2;
2351         BITv07_DStream_t bitD3;
2352         BITv07_DStream_t bitD4;
2353         size_t const length1 = MEM_readLE16(istart);
2354         size_t const length2 = MEM_readLE16(istart+2);
2355         size_t const length3 = MEM_readLE16(istart+4);
2356         size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
2357         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2358         const BYTE* const istart2 = istart1 + length1;
2359         const BYTE* const istart3 = istart2 + length2;
2360         const BYTE* const istart4 = istart3 + length3;
2361         size_t const segmentSize = (dstSize+3) / 4;
2362         BYTE* const opStart2 = ostart + segmentSize;
2363         BYTE* const opStart3 = opStart2 + segmentSize;
2364         BYTE* const opStart4 = opStart3 + segmentSize;
2365         BYTE* op1 = ostart;
2366         BYTE* op2 = opStart2;
2367         BYTE* op3 = opStart3;
2368         BYTE* op4 = opStart4;
2369         U32 endSignal;
2370         DTableDesc const dtd = HUFv07_getDTableDesc(DTable);
2371         U32 const dtLog = dtd.tableLog;
2372 
2373         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2374         { size_t const errorCode = BITv07_initDStream(&bitD1, istart1, length1);
2375           if (HUFv07_isError(errorCode)) return errorCode; }
2376         { size_t const errorCode = BITv07_initDStream(&bitD2, istart2, length2);
2377           if (HUFv07_isError(errorCode)) return errorCode; }
2378         { size_t const errorCode = BITv07_initDStream(&bitD3, istart3, length3);
2379           if (HUFv07_isError(errorCode)) return errorCode; }
2380         { size_t const errorCode = BITv07_initDStream(&bitD4, istart4, length4);
2381           if (HUFv07_isError(errorCode)) return errorCode; }
2382 
2383         /* 16-32 symbols per loop (4-8 symbols per stream) */
2384         endSignal = BITv07_reloadDStream(&bitD1) | BITv07_reloadDStream(&bitD2) | BITv07_reloadDStream(&bitD3) | BITv07_reloadDStream(&bitD4);
2385         for ( ; (endSignal==BITv07_DStream_unfinished) && (op4<(oend-7)) ; ) {
2386             HUFv07_DECODE_SYMBOLX4_2(op1, &bitD1);
2387             HUFv07_DECODE_SYMBOLX4_2(op2, &bitD2);
2388             HUFv07_DECODE_SYMBOLX4_2(op3, &bitD3);
2389             HUFv07_DECODE_SYMBOLX4_2(op4, &bitD4);
2390             HUFv07_DECODE_SYMBOLX4_1(op1, &bitD1);
2391             HUFv07_DECODE_SYMBOLX4_1(op2, &bitD2);
2392             HUFv07_DECODE_SYMBOLX4_1(op3, &bitD3);
2393             HUFv07_DECODE_SYMBOLX4_1(op4, &bitD4);
2394             HUFv07_DECODE_SYMBOLX4_2(op1, &bitD1);
2395             HUFv07_DECODE_SYMBOLX4_2(op2, &bitD2);
2396             HUFv07_DECODE_SYMBOLX4_2(op3, &bitD3);
2397             HUFv07_DECODE_SYMBOLX4_2(op4, &bitD4);
2398             HUFv07_DECODE_SYMBOLX4_0(op1, &bitD1);
2399             HUFv07_DECODE_SYMBOLX4_0(op2, &bitD2);
2400             HUFv07_DECODE_SYMBOLX4_0(op3, &bitD3);
2401             HUFv07_DECODE_SYMBOLX4_0(op4, &bitD4);
2402 
2403             endSignal = BITv07_reloadDStream(&bitD1) | BITv07_reloadDStream(&bitD2) | BITv07_reloadDStream(&bitD3) | BITv07_reloadDStream(&bitD4);
2404         }
2405 
2406         /* check corruption */
2407         if (op1 > opStart2) return ERROR(corruption_detected);
2408         if (op2 > opStart3) return ERROR(corruption_detected);
2409         if (op3 > opStart4) return ERROR(corruption_detected);
2410         /* note : op4 supposed already verified within main loop */
2411 
2412         /* finish bitStreams one by one */
2413         HUFv07_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
2414         HUFv07_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
2415         HUFv07_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
2416         HUFv07_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
2417 
2418         /* check */
2419         { U32 const endCheck = BITv07_endOfDStream(&bitD1) & BITv07_endOfDStream(&bitD2) & BITv07_endOfDStream(&bitD3) & BITv07_endOfDStream(&bitD4);
2420           if (!endCheck) return ERROR(corruption_detected); }
2421 
2422         /* decoded size */
2423         return dstSize;
2424     }
2425 }
2426 
2427 
2428 size_t HUFv07_decompress4X4_usingDTable(
2429           void* dst,  size_t dstSize,
2430     const void* cSrc, size_t cSrcSize,
2431     const HUFv07_DTable* DTable)
2432 {
2433     DTableDesc dtd = HUFv07_getDTableDesc(DTable);
2434     if (dtd.tableType != 1) return ERROR(GENERIC);
2435     return HUFv07_decompress4X4_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable);
2436 }
2437 
2438 
2439 size_t HUFv07_decompress4X4_DCtx (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2440 {
2441     const BYTE* ip = (const BYTE*) cSrc;
2442 
2443     size_t hSize = HUFv07_readDTableX4 (dctx, cSrc, cSrcSize);
2444     if (HUFv07_isError(hSize)) return hSize;
2445     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2446     ip += hSize; cSrcSize -= hSize;
2447 
2448     return HUFv07_decompress4X4_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx);
2449 }
2450 
2451 size_t HUFv07_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2452 {
2453     HUFv07_CREATE_STATIC_DTABLEX4(DTable, HUFv07_TABLELOG_MAX);
2454     return HUFv07_decompress4X4_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
2455 }
2456 
2457 
2458 /* ********************************/
2459 /* Generic decompression selector */
2460 /* ********************************/
2461 
2462 size_t HUFv07_decompress1X_usingDTable(void* dst, size_t maxDstSize,
2463                                     const void* cSrc, size_t cSrcSize,
2464                                     const HUFv07_DTable* DTable)
2465 {
2466     DTableDesc const dtd = HUFv07_getDTableDesc(DTable);
2467     return dtd.tableType ? HUFv07_decompress1X4_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable) :
2468                            HUFv07_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable);
2469 }
2470 
2471 size_t HUFv07_decompress4X_usingDTable(void* dst, size_t maxDstSize,
2472                                     const void* cSrc, size_t cSrcSize,
2473                                     const HUFv07_DTable* DTable)
2474 {
2475     DTableDesc const dtd = HUFv07_getDTableDesc(DTable);
2476     return dtd.tableType ? HUFv07_decompress4X4_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable) :
2477                            HUFv07_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable);
2478 }
2479 
2480 
2481 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
2482 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
2483 {
2484     /* single, double, quad */
2485     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
2486     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
2487     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
2488     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
2489     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
2490     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
2491     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
2492     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
2493     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
2494     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
2495     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
2496     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
2497     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
2498     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
2499     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
2500     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
2501 };
2502 
2503 /** HUFv07_selectDecoder() :
2504 *   Tells which decoder is likely to decode faster,
2505 *   based on a set of pre-determined metrics.
2506 *   @return : 0==HUFv07_decompress4X2, 1==HUFv07_decompress4X4 .
2507 *   Assumption : 0 < cSrcSize < dstSize <= 128 KB */
2508 U32 HUFv07_selectDecoder (size_t dstSize, size_t cSrcSize)
2509 {
2510     /* decoder timing evaluation */
2511     U32 const Q = (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 since dstSize > cSrcSize */
2512     U32 const D256 = (U32)(dstSize >> 8);
2513     U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256);
2514     U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256);
2515     DTime1 += DTime1 >> 3;  /* advantage to algorithm using less memory, for cache eviction */
2516 
2517     return DTime1 < DTime0;
2518 }
2519 
2520 
2521 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
2522 
2523 size_t HUFv07_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2524 {
2525     static const decompressionAlgo decompress[2] = { HUFv07_decompress4X2, HUFv07_decompress4X4 };
2526 
2527     /* validation checks */
2528     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2529     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2530     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2531     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2532 
2533     {   U32 const algoNb = HUFv07_selectDecoder(dstSize, cSrcSize);
2534         return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
2535     }
2536 
2537     /* return HUFv07_decompress4X2(dst, dstSize, cSrc, cSrcSize); */   /* multi-streams single-symbol decoding */
2538     /* return HUFv07_decompress4X4(dst, dstSize, cSrc, cSrcSize); */   /* multi-streams double-symbols decoding */
2539 }
2540 
2541 size_t HUFv07_decompress4X_DCtx (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2542 {
2543     /* validation checks */
2544     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2545     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2546     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2547     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2548 
2549     {   U32 const algoNb = HUFv07_selectDecoder(dstSize, cSrcSize);
2550         return algoNb ? HUFv07_decompress4X4_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) :
2551                         HUFv07_decompress4X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) ;
2552     }
2553 }
2554 
2555 size_t HUFv07_decompress4X_hufOnly (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2556 {
2557     /* validation checks */
2558     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2559     if ((cSrcSize >= dstSize) || (cSrcSize <= 1)) return ERROR(corruption_detected);   /* invalid */
2560 
2561     {   U32 const algoNb = HUFv07_selectDecoder(dstSize, cSrcSize);
2562         return algoNb ? HUFv07_decompress4X4_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) :
2563                         HUFv07_decompress4X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) ;
2564     }
2565 }
2566 
2567 size_t HUFv07_decompress1X_DCtx (HUFv07_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2568 {
2569     /* validation checks */
2570     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2571     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2572     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2573     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2574 
2575     {   U32 const algoNb = HUFv07_selectDecoder(dstSize, cSrcSize);
2576         return algoNb ? HUFv07_decompress1X4_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) :
2577                         HUFv07_decompress1X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) ;
2578     }
2579 }
2580 /*
2581     Common functions of Zstd compression library
2582     Copyright (C) 2015-2016, Yann Collet.
2583 
2584     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2585 
2586     Redistribution and use in source and binary forms, with or without
2587     modification, are permitted provided that the following conditions are
2588     met:
2589     * Redistributions of source code must retain the above copyright
2590     notice, this list of conditions and the following disclaimer.
2591     * Redistributions in binary form must reproduce the above
2592     copyright notice, this list of conditions and the following disclaimer
2593     in the documentation and/or other materials provided with the
2594     distribution.
2595     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2596     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2597     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2598     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2599     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2600     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2601     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2602     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2603     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2604     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2605     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2606 
2607     You can contact the author at :
2608     - zstd homepage : http://www.zstd.net/
2609 */
2610 
2611 
2612 
2613 /*-****************************************
2614 *  ZSTD Error Management
2615 ******************************************/
2616 /*! ZSTDv07_isError() :
2617 *   tells if a return value is an error code */
2618 unsigned ZSTDv07_isError(size_t code) { return ERR_isError(code); }
2619 
2620 /*! ZSTDv07_getErrorName() :
2621 *   provides error code string from function result (useful for debugging) */
2622 const char* ZSTDv07_getErrorName(size_t code) { return ERR_getErrorName(code); }
2623 
2624 
2625 
2626 /* **************************************************************
2627 *  ZBUFF Error Management
2628 ****************************************************************/
2629 unsigned ZBUFFv07_isError(size_t errorCode) { return ERR_isError(errorCode); }
2630 
2631 const char* ZBUFFv07_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
2632 
2633 
2634 
2635 static void* ZSTDv07_defaultAllocFunction(void* opaque, size_t size)
2636 {
2637     void* address = malloc(size);
2638     (void)opaque;
2639     /* printf("alloc %p, %d opaque=%p \n", address, (int)size, opaque); */
2640     return address;
2641 }
2642 
2643 static void ZSTDv07_defaultFreeFunction(void* opaque, void* address)
2644 {
2645     (void)opaque;
2646     /* if (address) printf("free %p opaque=%p \n", address, opaque); */
2647     free(address);
2648 }
2649 /*
2650     zstd_internal - common functions to include
2651     Header File for include
2652     Copyright (C) 2014-2016, Yann Collet.
2653 
2654     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2655 
2656     Redistribution and use in source and binary forms, with or without
2657     modification, are permitted provided that the following conditions are
2658     met:
2659     * Redistributions of source code must retain the above copyright
2660     notice, this list of conditions and the following disclaimer.
2661     * Redistributions in binary form must reproduce the above
2662     copyright notice, this list of conditions and the following disclaimer
2663     in the documentation and/or other materials provided with the
2664     distribution.
2665     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2666     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2667     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2668     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2669     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2670     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2671     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2672     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2673     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2674     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2675     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2676 
2677     You can contact the author at :
2678     - zstd homepage : https://www.zstd.net
2679 */
2680 #ifndef ZSTDv07_CCOMMON_H_MODULE
2681 #define ZSTDv07_CCOMMON_H_MODULE
2682 
2683 
2684 /*-*************************************
2685 *  Common macros
2686 ***************************************/
2687 #define MIN(a,b) ((a)<(b) ? (a) : (b))
2688 #define MAX(a,b) ((a)>(b) ? (a) : (b))
2689 
2690 
2691 /*-*************************************
2692 *  Common constants
2693 ***************************************/
2694 #define ZSTDv07_OPT_NUM    (1<<12)
2695 #define ZSTDv07_DICT_MAGIC  0xEC30A437   /* v0.7 */
2696 
2697 #define ZSTDv07_REP_NUM    3
2698 #define ZSTDv07_REP_INIT   ZSTDv07_REP_NUM
2699 #define ZSTDv07_REP_MOVE   (ZSTDv07_REP_NUM-1)
2700 static const U32 repStartValue[ZSTDv07_REP_NUM] = { 1, 4, 8 };
2701 
2702 #define KB *(1 <<10)
2703 #define MB *(1 <<20)
2704 #define GB *(1U<<30)
2705 
2706 #define BIT7 128
2707 #define BIT6  64
2708 #define BIT5  32
2709 #define BIT4  16
2710 #define BIT1   2
2711 #define BIT0   1
2712 
2713 #define ZSTDv07_WINDOWLOG_ABSOLUTEMIN 10
2714 static const size_t ZSTDv07_fcs_fieldSize[4] = { 0, 2, 4, 8 };
2715 static const size_t ZSTDv07_did_fieldSize[4] = { 0, 1, 2, 4 };
2716 
2717 #define ZSTDv07_BLOCKHEADERSIZE 3   /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
2718 static const size_t ZSTDv07_blockHeaderSize = ZSTDv07_BLOCKHEADERSIZE;
2719 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
2720 
2721 #define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */
2722 #define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */)   /* for a non-null block */
2723 
2724 #define HufLog 12
2725 typedef enum { lbt_huffman, lbt_repeat, lbt_raw, lbt_rle } litBlockType_t;
2726 
2727 #define LONGNBSEQ 0x7F00
2728 
2729 #define MINMATCH 3
2730 #define EQUAL_READ32 4
2731 
2732 #define Litbits  8
2733 #define MaxLit ((1<<Litbits) - 1)
2734 #define MaxML  52
2735 #define MaxLL  35
2736 #define MaxOff 28
2737 #define MaxSeq MAX(MaxLL, MaxML)   /* Assumption : MaxOff < MaxLL,MaxML */
2738 #define MLFSELog    9
2739 #define LLFSELog    9
2740 #define OffFSELog   8
2741 
2742 #define FSEv07_ENCODING_RAW     0
2743 #define FSEv07_ENCODING_RLE     1
2744 #define FSEv07_ENCODING_STATIC  2
2745 #define FSEv07_ENCODING_DYNAMIC 3
2746 
2747 #define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
2748 
2749 static const U32 LL_bits[MaxLL+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
2750                                       1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9,10,11,12,
2751                                      13,14,15,16 };
2752 static const S16 LL_defaultNorm[MaxLL+1] = { 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1,
2753                                              2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1,
2754                                             -1,-1,-1,-1 };
2755 static const U32 LL_defaultNormLog = 6;
2756 
2757 static const U32 ML_bits[MaxML+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
2758                                       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
2759                                       1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9,10,11,
2760                                      12,13,14,15,16 };
2761 static const S16 ML_defaultNorm[MaxML+1] = { 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
2762                                              1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
2763                                              1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,
2764                                             -1,-1,-1,-1,-1 };
2765 static const U32 ML_defaultNormLog = 6;
2766 
2767 static const S16 OF_defaultNorm[MaxOff+1] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
2768                                               1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1,-1,-1 };
2769 static const U32 OF_defaultNormLog = 5;
2770 
2771 
2772 /*-*******************************************
2773 *  Shared functions to include for inlining
2774 *********************************************/
2775 static void ZSTDv07_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
2776 #define COPY8(d,s) { ZSTDv07_copy8(d,s); d+=8; s+=8; }
2777 
2778 /*! ZSTDv07_wildcopy() :
2779 *   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
2780 #define WILDCOPY_OVERLENGTH 8
2781 MEM_STATIC void ZSTDv07_wildcopy(void* dst, const void* src, ptrdiff_t length)
2782 {
2783     const BYTE* ip = (const BYTE*)src;
2784     BYTE* op = (BYTE*)dst;
2785     BYTE* const oend = op + length;
2786     do
2787         COPY8(op, ip)
2788     while (op < oend);
2789 }
2790 
2791 
2792 /*-*******************************************
2793 *  Private interfaces
2794 *********************************************/
2795 typedef struct ZSTDv07_stats_s ZSTDv07_stats_t;
2796 
2797 typedef struct {
2798     U32 off;
2799     U32 len;
2800 } ZSTDv07_match_t;
2801 
2802 typedef struct {
2803     U32 price;
2804     U32 off;
2805     U32 mlen;
2806     U32 litlen;
2807     U32 rep[ZSTDv07_REP_INIT];
2808 } ZSTDv07_optimal_t;
2809 
2810 struct ZSTDv07_stats_s { U32 unused; };
2811 
2812 typedef struct {
2813     void* buffer;
2814     U32*  offsetStart;
2815     U32*  offset;
2816     BYTE* offCodeStart;
2817     BYTE* litStart;
2818     BYTE* lit;
2819     U16*  litLengthStart;
2820     U16*  litLength;
2821     BYTE* llCodeStart;
2822     U16*  matchLengthStart;
2823     U16*  matchLength;
2824     BYTE* mlCodeStart;
2825     U32   longLengthID;   /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
2826     U32   longLengthPos;
2827     /* opt */
2828     ZSTDv07_optimal_t* priceTable;
2829     ZSTDv07_match_t* matchTable;
2830     U32* matchLengthFreq;
2831     U32* litLengthFreq;
2832     U32* litFreq;
2833     U32* offCodeFreq;
2834     U32  matchLengthSum;
2835     U32  matchSum;
2836     U32  litLengthSum;
2837     U32  litSum;
2838     U32  offCodeSum;
2839     U32  log2matchLengthSum;
2840     U32  log2matchSum;
2841     U32  log2litLengthSum;
2842     U32  log2litSum;
2843     U32  log2offCodeSum;
2844     U32  factor;
2845     U32  cachedPrice;
2846     U32  cachedLitLength;
2847     const BYTE* cachedLiterals;
2848     ZSTDv07_stats_t stats;
2849 } seqStore_t;
2850 
2851 void ZSTDv07_seqToCodes(const seqStore_t* seqStorePtr, size_t const nbSeq);
2852 
2853 /* custom memory allocation functions */
2854 static const ZSTDv07_customMem defaultCustomMem = { ZSTDv07_defaultAllocFunction, ZSTDv07_defaultFreeFunction, NULL };
2855 
2856 #endif   /* ZSTDv07_CCOMMON_H_MODULE */
2857 /*
2858     zstd - standard compression library
2859     Copyright (C) 2014-2016, Yann Collet.
2860 
2861     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2862 
2863     Redistribution and use in source and binary forms, with or without
2864     modification, are permitted provided that the following conditions are
2865     met:
2866     * Redistributions of source code must retain the above copyright
2867     notice, this list of conditions and the following disclaimer.
2868     * Redistributions in binary form must reproduce the above
2869     copyright notice, this list of conditions and the following disclaimer
2870     in the documentation and/or other materials provided with the
2871     distribution.
2872     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2873     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2874     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2875     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2876     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2877     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2878     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2879     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2880     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2881     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2882     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2883 
2884     You can contact the author at :
2885     - zstd homepage : http://www.zstd.net
2886 */
2887 
2888 /* ***************************************************************
2889 *  Tuning parameters
2890 *****************************************************************/
2891 /*!
2892  * HEAPMODE :
2893  * Select how default decompression function ZSTDv07_decompress() will allocate memory,
2894  * in memory stack (0), or in memory heap (1, requires malloc())
2895  */
2896 #ifndef ZSTDv07_HEAPMODE
2897 #  define ZSTDv07_HEAPMODE 1
2898 #endif
2899 
2900 
2901 /*-*******************************************************
2902 *  Compiler specifics
2903 *********************************************************/
2904 #ifdef _MSC_VER    /* Visual Studio */
2905 #  include <intrin.h>                    /* For Visual 2005 */
2906 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
2907 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
2908 #  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
2909 #endif
2910 
2911 
2912 /*-*************************************
2913 *  Macros
2914 ***************************************/
2915 #define ZSTDv07_isError ERR_isError   /* for inlining */
2916 #define FSEv07_isError  ERR_isError
2917 #define HUFv07_isError  ERR_isError
2918 
2919 
2920 /*_*******************************************************
2921 *  Memory operations
2922 **********************************************************/
2923 static void ZSTDv07_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
2924 
2925 
2926 /*-*************************************************************
2927 *   Context management
2928 ***************************************************************/
2929 typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
2930                ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
2931                ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTDv07_dStage;
2932 
2933 struct ZSTDv07_DCtx_s
2934 {
2935     FSEv07_DTable LLTable[FSEv07_DTABLE_SIZE_U32(LLFSELog)];
2936     FSEv07_DTable OffTable[FSEv07_DTABLE_SIZE_U32(OffFSELog)];
2937     FSEv07_DTable MLTable[FSEv07_DTABLE_SIZE_U32(MLFSELog)];
2938     HUFv07_DTable hufTable[HUFv07_DTABLE_SIZE(HufLog)];  /* can accommodate HUFv07_decompress4X */
2939     const void* previousDstEnd;
2940     const void* base;
2941     const void* vBase;
2942     const void* dictEnd;
2943     size_t expected;
2944     U32 rep[3];
2945     ZSTDv07_frameParams fParams;
2946     blockType_t bType;   /* used in ZSTDv07_decompressContinue(), to transfer blockType between header decoding and block decoding stages */
2947     ZSTDv07_dStage stage;
2948     U32 litEntropy;
2949     U32 fseEntropy;
2950     XXH64_state_t xxhState;
2951     size_t headerSize;
2952     U32 dictID;
2953     const BYTE* litPtr;
2954     ZSTDv07_customMem customMem;
2955     size_t litSize;
2956     BYTE litBuffer[ZSTDv07_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH];
2957     BYTE headerBuffer[ZSTDv07_FRAMEHEADERSIZE_MAX];
2958 };  /* typedef'd to ZSTDv07_DCtx within "zstd_static.h" */
2959 
2960 int ZSTDv07_isSkipFrame(ZSTDv07_DCtx* dctx);
2961 
2962 size_t ZSTDv07_sizeofDCtx (const ZSTDv07_DCtx* dctx) { return sizeof(*dctx); }
2963 
2964 size_t ZSTDv07_estimateDCtxSize(void) { return sizeof(ZSTDv07_DCtx); }
2965 
2966 size_t ZSTDv07_decompressBegin(ZSTDv07_DCtx* dctx)
2967 {
2968     dctx->expected = ZSTDv07_frameHeaderSize_min;
2969     dctx->stage = ZSTDds_getFrameHeaderSize;
2970     dctx->previousDstEnd = NULL;
2971     dctx->base = NULL;
2972     dctx->vBase = NULL;
2973     dctx->dictEnd = NULL;
2974     dctx->hufTable[0] = (HUFv07_DTable)((HufLog)*0x1000001);
2975     dctx->litEntropy = dctx->fseEntropy = 0;
2976     dctx->dictID = 0;
2977     { int i; for (i=0; i<ZSTDv07_REP_NUM; i++) dctx->rep[i] = repStartValue[i]; }
2978     return 0;
2979 }
2980 
2981 ZSTDv07_DCtx* ZSTDv07_createDCtx_advanced(ZSTDv07_customMem customMem)
2982 {
2983     ZSTDv07_DCtx* dctx;
2984 
2985     if (!customMem.customAlloc && !customMem.customFree)
2986         customMem = defaultCustomMem;
2987 
2988     if (!customMem.customAlloc || !customMem.customFree)
2989         return NULL;
2990 
2991     dctx = (ZSTDv07_DCtx*) customMem.customAlloc(customMem.opaque, sizeof(ZSTDv07_DCtx));
2992     if (!dctx) return NULL;
2993     memcpy(&dctx->customMem, &customMem, sizeof(ZSTDv07_customMem));
2994     ZSTDv07_decompressBegin(dctx);
2995     return dctx;
2996 }
2997 
2998 ZSTDv07_DCtx* ZSTDv07_createDCtx(void)
2999 {
3000     return ZSTDv07_createDCtx_advanced(defaultCustomMem);
3001 }
3002 
3003 size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx)
3004 {
3005     if (dctx==NULL) return 0;   /* support free on NULL */
3006     dctx->customMem.customFree(dctx->customMem.opaque, dctx);
3007     return 0;   /* reserved as a potential error code in the future */
3008 }
3009 
3010 void ZSTDv07_copyDCtx(ZSTDv07_DCtx* dstDCtx, const ZSTDv07_DCtx* srcDCtx)
3011 {
3012     memcpy(dstDCtx, srcDCtx,
3013            sizeof(ZSTDv07_DCtx) - (ZSTDv07_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH + ZSTDv07_frameHeaderSize_max));  /* no need to copy workspace */
3014 }
3015 
3016 
3017 /*-*************************************************************
3018 *   Decompression section
3019 ***************************************************************/
3020 
3021 /* Frame format description
3022    Frame Header -  [ Block Header - Block ] - Frame End
3023    1) Frame Header
3024       - 4 bytes - Magic Number : ZSTDv07_MAGICNUMBER (defined within zstd.h)
3025       - 1 byte  - Frame Descriptor
3026    2) Block Header
3027       - 3 bytes, starting with a 2-bits descriptor
3028                  Uncompressed, Compressed, Frame End, unused
3029    3) Block
3030       See Block Format Description
3031    4) Frame End
3032       - 3 bytes, compatible with Block Header
3033 */
3034 
3035 
3036 /* Frame Header :
3037 
3038    1 byte - FrameHeaderDescription :
3039    bit 0-1 : dictID (0, 1, 2 or 4 bytes)
3040    bit 2   : checksumFlag
3041    bit 3   : reserved (must be zero)
3042    bit 4   : reserved (unused, can be any value)
3043    bit 5   : Single Segment (if 1, WindowLog byte is not present)
3044    bit 6-7 : FrameContentFieldSize (0, 2, 4, or 8)
3045              if (SkippedWindowLog && !FrameContentFieldsize) FrameContentFieldsize=1;
3046 
3047    Optional : WindowLog (0 or 1 byte)
3048    bit 0-2 : octal Fractional (1/8th)
3049    bit 3-7 : Power of 2, with 0 = 1 KB (up to 2 TB)
3050 
3051    Optional : dictID (0, 1, 2 or 4 bytes)
3052    Automatic adaptation
3053    0 : no dictID
3054    1 : 1 - 255
3055    2 : 256 - 65535
3056    4 : all other values
3057 
3058    Optional : content size (0, 1, 2, 4 or 8 bytes)
3059    0 : unknown          (fcfs==0 and swl==0)
3060    1 : 0-255 bytes      (fcfs==0 and swl==1)
3061    2 : 256 - 65535+256  (fcfs==1)
3062    4 : 0 - 4GB-1        (fcfs==2)
3063    8 : 0 - 16EB-1       (fcfs==3)
3064 */
3065 
3066 
3067 /* Compressed Block, format description
3068 
3069    Block = Literal Section - Sequences Section
3070    Prerequisite : size of (compressed) block, maximum size of regenerated data
3071 
3072    1) Literal Section
3073 
3074    1.1) Header : 1-5 bytes
3075         flags: 2 bits
3076             00 compressed by Huff0
3077             01 unused
3078             10 is Raw (uncompressed)
3079             11 is Rle
3080             Note : using 01 => Huff0 with precomputed table ?
3081             Note : delta map ? => compressed ?
3082 
3083    1.1.1) Huff0-compressed literal block : 3-5 bytes
3084             srcSize < 1 KB => 3 bytes (2-2-10-10) => single stream
3085             srcSize < 1 KB => 3 bytes (2-2-10-10)
3086             srcSize < 16KB => 4 bytes (2-2-14-14)
3087             else           => 5 bytes (2-2-18-18)
3088             big endian convention
3089 
3090    1.1.2) Raw (uncompressed) literal block header : 1-3 bytes
3091         size :  5 bits: (IS_RAW<<6) + (0<<4) + size
3092                12 bits: (IS_RAW<<6) + (2<<4) + (size>>8)
3093                         size&255
3094                20 bits: (IS_RAW<<6) + (3<<4) + (size>>16)
3095                         size>>8&255
3096                         size&255
3097 
3098    1.1.3) Rle (repeated single byte) literal block header : 1-3 bytes
3099         size :  5 bits: (IS_RLE<<6) + (0<<4) + size
3100                12 bits: (IS_RLE<<6) + (2<<4) + (size>>8)
3101                         size&255
3102                20 bits: (IS_RLE<<6) + (3<<4) + (size>>16)
3103                         size>>8&255
3104                         size&255
3105 
3106    1.1.4) Huff0-compressed literal block, using precomputed CTables : 3-5 bytes
3107             srcSize < 1 KB => 3 bytes (2-2-10-10) => single stream
3108             srcSize < 1 KB => 3 bytes (2-2-10-10)
3109             srcSize < 16KB => 4 bytes (2-2-14-14)
3110             else           => 5 bytes (2-2-18-18)
3111             big endian convention
3112 
3113         1- CTable available (stored into workspace ?)
3114         2- Small input (fast heuristic ? Full comparison ? depend on clevel ?)
3115 
3116 
3117    1.2) Literal block content
3118 
3119    1.2.1) Huff0 block, using sizes from header
3120         See Huff0 format
3121 
3122    1.2.2) Huff0 block, using prepared table
3123 
3124    1.2.3) Raw content
3125 
3126    1.2.4) single byte
3127 
3128 
3129    2) Sequences section
3130       TO DO
3131 */
3132 
3133 /** ZSTDv07_frameHeaderSize() :
3134 *   srcSize must be >= ZSTDv07_frameHeaderSize_min.
3135 *   @return : size of the Frame Header */
3136 static size_t ZSTDv07_frameHeaderSize(const void* src, size_t srcSize)
3137 {
3138     if (srcSize < ZSTDv07_frameHeaderSize_min) return ERROR(srcSize_wrong);
3139     {   BYTE const fhd = ((const BYTE*)src)[4];
3140         U32 const dictID= fhd & 3;
3141         U32 const directMode = (fhd >> 5) & 1;
3142         U32 const fcsId = fhd >> 6;
3143         return ZSTDv07_frameHeaderSize_min + !directMode + ZSTDv07_did_fieldSize[dictID] + ZSTDv07_fcs_fieldSize[fcsId]
3144                 + (directMode && !ZSTDv07_fcs_fieldSize[fcsId]);
3145     }
3146 }
3147 
3148 
3149 /** ZSTDv07_getFrameParams() :
3150 *   decode Frame Header, or require larger `srcSize`.
3151 *   @return : 0, `fparamsPtr` is correctly filled,
3152 *            >0, `srcSize` is too small, result is expected `srcSize`,
3153 *             or an error code, which can be tested using ZSTDv07_isError() */
3154 size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize)
3155 {
3156     const BYTE* ip = (const BYTE*)src;
3157 
3158     if (srcSize < ZSTDv07_frameHeaderSize_min) return ZSTDv07_frameHeaderSize_min;
3159     memset(fparamsPtr, 0, sizeof(*fparamsPtr));
3160     if (MEM_readLE32(src) != ZSTDv07_MAGICNUMBER) {
3161         if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTDv07_MAGIC_SKIPPABLE_START) {
3162             if (srcSize < ZSTDv07_skippableHeaderSize) return ZSTDv07_skippableHeaderSize; /* magic number + skippable frame length */
3163             fparamsPtr->frameContentSize = MEM_readLE32((const char *)src + 4);
3164             fparamsPtr->windowSize = 0; /* windowSize==0 means a frame is skippable */
3165             return 0;
3166         }
3167         return ERROR(prefix_unknown);
3168     }
3169 
3170     /* ensure there is enough `srcSize` to fully read/decode frame header */
3171     { size_t const fhsize = ZSTDv07_frameHeaderSize(src, srcSize);
3172       if (srcSize < fhsize) return fhsize; }
3173 
3174     {   BYTE const fhdByte = ip[4];
3175         size_t pos = 5;
3176         U32 const dictIDSizeCode = fhdByte&3;
3177         U32 const checksumFlag = (fhdByte>>2)&1;
3178         U32 const directMode = (fhdByte>>5)&1;
3179         U32 const fcsID = fhdByte>>6;
3180         U32 const windowSizeMax = 1U << ZSTDv07_WINDOWLOG_MAX;
3181         U32 windowSize = 0;
3182         U32 dictID = 0;
3183         U64 frameContentSize = 0;
3184         if ((fhdByte & 0x08) != 0)   /* reserved bits, which must be zero */
3185             return ERROR(frameParameter_unsupported);
3186         if (!directMode) {
3187             BYTE const wlByte = ip[pos++];
3188             U32 const windowLog = (wlByte >> 3) + ZSTDv07_WINDOWLOG_ABSOLUTEMIN;
3189             if (windowLog > ZSTDv07_WINDOWLOG_MAX)
3190                 return ERROR(frameParameter_unsupported);
3191             windowSize = (1U << windowLog);
3192             windowSize += (windowSize >> 3) * (wlByte&7);
3193         }
3194 
3195         switch(dictIDSizeCode)
3196         {
3197             default:   /* impossible */
3198             case 0 : break;
3199             case 1 : dictID = ip[pos]; pos++; break;
3200             case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
3201             case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
3202         }
3203         switch(fcsID)
3204         {
3205             default:   /* impossible */
3206             case 0 : if (directMode) frameContentSize = ip[pos]; break;
3207             case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
3208             case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
3209             case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
3210         }
3211         if (!windowSize) windowSize = (U32)frameContentSize;
3212         if (windowSize > windowSizeMax)
3213             return ERROR(frameParameter_unsupported);
3214         fparamsPtr->frameContentSize = frameContentSize;
3215         fparamsPtr->windowSize = windowSize;
3216         fparamsPtr->dictID = dictID;
3217         fparamsPtr->checksumFlag = checksumFlag;
3218     }
3219     return 0;
3220 }
3221 
3222 
3223 /** ZSTDv07_getDecompressedSize() :
3224 *   compatible with legacy mode
3225 *   @return : decompressed size if known, 0 otherwise
3226               note : 0 can mean any of the following :
3227                    - decompressed size is not provided within frame header
3228                    - frame header unknown / not supported
3229                    - frame header not completely provided (`srcSize` too small) */
3230 unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize)
3231 {
3232     ZSTDv07_frameParams fparams;
3233     size_t const frResult = ZSTDv07_getFrameParams(&fparams, src, srcSize);
3234     if (frResult!=0) return 0;
3235     return fparams.frameContentSize;
3236 }
3237 
3238 
3239 /** ZSTDv07_decodeFrameHeader() :
3240 *   `srcSize` must be the size provided by ZSTDv07_frameHeaderSize().
3241 *   @return : 0 if success, or an error code, which can be tested using ZSTDv07_isError() */
3242 static size_t ZSTDv07_decodeFrameHeader(ZSTDv07_DCtx* dctx, const void* src, size_t srcSize)
3243 {
3244     size_t const result = ZSTDv07_getFrameParams(&(dctx->fParams), src, srcSize);
3245     if (dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID)) return ERROR(dictionary_wrong);
3246     if (dctx->fParams.checksumFlag) XXH64_reset(&dctx->xxhState, 0);
3247     return result;
3248 }
3249 
3250 
3251 typedef struct
3252 {
3253     blockType_t blockType;
3254     U32 origSize;
3255 } blockProperties_t;
3256 
3257 /*! ZSTDv07_getcBlockSize() :
3258 *   Provides the size of compressed block from block header `src` */
3259 static size_t ZSTDv07_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
3260 {
3261     const BYTE* const in = (const BYTE* const)src;
3262     U32 cSize;
3263 
3264     if (srcSize < ZSTDv07_blockHeaderSize) return ERROR(srcSize_wrong);
3265 
3266     bpPtr->blockType = (blockType_t)((*in) >> 6);
3267     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
3268     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
3269 
3270     if (bpPtr->blockType == bt_end) return 0;
3271     if (bpPtr->blockType == bt_rle) return 1;
3272     return cSize;
3273 }
3274 
3275 
3276 static size_t ZSTDv07_copyRawBlock(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
3277 {
3278     if (srcSize > dstCapacity) return ERROR(dstSize_tooSmall);
3279     if (srcSize > 0) {
3280         memcpy(dst, src, srcSize);
3281     }
3282     return srcSize;
3283 }
3284 
3285 
3286 /*! ZSTDv07_decodeLiteralsBlock() :
3287     @return : nb of bytes read from src (< srcSize ) */
3288 static size_t ZSTDv07_decodeLiteralsBlock(ZSTDv07_DCtx* dctx,
3289                           const void* src, size_t srcSize)   /* note : srcSize < BLOCKSIZE */
3290 {
3291     const BYTE* const istart = (const BYTE*) src;
3292 
3293     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
3294 
3295     switch((litBlockType_t)(istart[0]>> 6))
3296     {
3297     case lbt_huffman:
3298         {   size_t litSize, litCSize, singleStream=0;
3299             U32 lhSize = (istart[0] >> 4) & 3;
3300             if (srcSize < 5) return ERROR(corruption_detected);   /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for lhSize, + cSize (+nbSeq) */
3301             switch(lhSize)
3302             {
3303             case 0: case 1: default:   /* note : default is impossible, since lhSize into [0..3] */
3304                 /* 2 - 2 - 10 - 10 */
3305                 lhSize=3;
3306                 singleStream = istart[0] & 16;
3307                 litSize  = ((istart[0] & 15) << 6) + (istart[1] >> 2);
3308                 litCSize = ((istart[1] &  3) << 8) + istart[2];
3309                 break;
3310             case 2:
3311                 /* 2 - 2 - 14 - 14 */
3312                 lhSize=4;
3313                 litSize  = ((istart[0] & 15) << 10) + (istart[1] << 2) + (istart[2] >> 6);
3314                 litCSize = ((istart[2] & 63) <<  8) + istart[3];
3315                 break;
3316             case 3:
3317                 /* 2 - 2 - 18 - 18 */
3318                 lhSize=5;
3319                 litSize  = ((istart[0] & 15) << 14) + (istart[1] << 6) + (istart[2] >> 2);
3320                 litCSize = ((istart[2] &  3) << 16) + (istart[3] << 8) + istart[4];
3321                 break;
3322             }
3323             if (litSize > ZSTDv07_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
3324             if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
3325 
3326             if (HUFv07_isError(singleStream ?
3327                             HUFv07_decompress1X2_DCtx(dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) :
3328                             HUFv07_decompress4X_hufOnly (dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) ))
3329                 return ERROR(corruption_detected);
3330 
3331             dctx->litPtr = dctx->litBuffer;
3332             dctx->litSize = litSize;
3333             dctx->litEntropy = 1;
3334             memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
3335             return litCSize + lhSize;
3336         }
3337     case lbt_repeat:
3338         {   size_t litSize, litCSize;
3339             U32 lhSize = ((istart[0]) >> 4) & 3;
3340             if (lhSize != 1)  /* only case supported for now : small litSize, single stream */
3341                 return ERROR(corruption_detected);
3342             if (dctx->litEntropy==0)
3343                 return ERROR(dictionary_corrupted);
3344 
3345             /* 2 - 2 - 10 - 10 */
3346             lhSize=3;
3347             litSize  = ((istart[0] & 15) << 6) + (istart[1] >> 2);
3348             litCSize = ((istart[1] &  3) << 8) + istart[2];
3349             if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
3350 
3351             {   size_t const errorCode = HUFv07_decompress1X4_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTable);
3352                 if (HUFv07_isError(errorCode)) return ERROR(corruption_detected);
3353             }
3354             dctx->litPtr = dctx->litBuffer;
3355             dctx->litSize = litSize;
3356             memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
3357             return litCSize + lhSize;
3358         }
3359     case lbt_raw:
3360         {   size_t litSize;
3361             U32 lhSize = ((istart[0]) >> 4) & 3;
3362             switch(lhSize)
3363             {
3364             case 0: case 1: default:   /* note : default is impossible, since lhSize into [0..3] */
3365                 lhSize=1;
3366                 litSize = istart[0] & 31;
3367                 break;
3368             case 2:
3369                 litSize = ((istart[0] & 15) << 8) + istart[1];
3370                 break;
3371             case 3:
3372                 litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2];
3373                 break;
3374             }
3375 
3376             if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) {  /* risk reading beyond src buffer with wildcopy */
3377                 if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
3378                 memcpy(dctx->litBuffer, istart+lhSize, litSize);
3379                 dctx->litPtr = dctx->litBuffer;
3380                 dctx->litSize = litSize;
3381                 memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
3382                 return lhSize+litSize;
3383             }
3384             /* direct reference into compressed stream */
3385             dctx->litPtr = istart+lhSize;
3386             dctx->litSize = litSize;
3387             return lhSize+litSize;
3388         }
3389     case lbt_rle:
3390         {   size_t litSize;
3391             U32 lhSize = ((istart[0]) >> 4) & 3;
3392             switch(lhSize)
3393             {
3394             case 0: case 1: default:   /* note : default is impossible, since lhSize into [0..3] */
3395                 lhSize = 1;
3396                 litSize = istart[0] & 31;
3397                 break;
3398             case 2:
3399                 litSize = ((istart[0] & 15) << 8) + istart[1];
3400                 break;
3401             case 3:
3402                 litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2];
3403                 if (srcSize<4) return ERROR(corruption_detected);   /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
3404                 break;
3405             }
3406             if (litSize > ZSTDv07_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
3407             memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH);
3408             dctx->litPtr = dctx->litBuffer;
3409             dctx->litSize = litSize;
3410             return lhSize+1;
3411         }
3412     default:
3413         return ERROR(corruption_detected);   /* impossible */
3414     }
3415 }
3416 
3417 
3418 /*! ZSTDv07_buildSeqTable() :
3419     @return : nb bytes read from src,
3420               or an error code if it fails, testable with ZSTDv07_isError()
3421 */
3422 static size_t ZSTDv07_buildSeqTable(FSEv07_DTable* DTable, U32 type, U32 max, U32 maxLog,
3423                                  const void* src, size_t srcSize,
3424                                  const S16* defaultNorm, U32 defaultLog, U32 flagRepeatTable)
3425 {
3426     switch(type)
3427     {
3428     case FSEv07_ENCODING_RLE :
3429         if (!srcSize) return ERROR(srcSize_wrong);
3430         if ( (*(const BYTE*)src) > max) return ERROR(corruption_detected);
3431         FSEv07_buildDTable_rle(DTable, *(const BYTE*)src);   /* if *src > max, data is corrupted */
3432         return 1;
3433     case FSEv07_ENCODING_RAW :
3434         FSEv07_buildDTable(DTable, defaultNorm, max, defaultLog);
3435         return 0;
3436     case FSEv07_ENCODING_STATIC:
3437         if (!flagRepeatTable) return ERROR(corruption_detected);
3438         return 0;
3439     default :   /* impossible */
3440     case FSEv07_ENCODING_DYNAMIC :
3441         {   U32 tableLog;
3442             S16 norm[MaxSeq+1];
3443             size_t const headerSize = FSEv07_readNCount(norm, &max, &tableLog, src, srcSize);
3444             if (FSEv07_isError(headerSize)) return ERROR(corruption_detected);
3445             if (tableLog > maxLog) return ERROR(corruption_detected);
3446             FSEv07_buildDTable(DTable, norm, max, tableLog);
3447             return headerSize;
3448     }   }
3449 }
3450 
3451 
3452 static size_t ZSTDv07_decodeSeqHeaders(int* nbSeqPtr,
3453                              FSEv07_DTable* DTableLL, FSEv07_DTable* DTableML, FSEv07_DTable* DTableOffb, U32 flagRepeatTable,
3454                              const void* src, size_t srcSize)
3455 {
3456     const BYTE* const istart = (const BYTE* const)src;
3457     const BYTE* const iend = istart + srcSize;
3458     const BYTE* ip = istart;
3459 
3460     /* check */
3461     if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong);
3462 
3463     /* SeqHead */
3464     {   int nbSeq = *ip++;
3465         if (!nbSeq) { *nbSeqPtr=0; return 1; }
3466         if (nbSeq > 0x7F) {
3467             if (nbSeq == 0xFF) {
3468                 if (ip+2 > iend) return ERROR(srcSize_wrong);
3469                 nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2;
3470             } else {
3471                 if (ip >= iend) return ERROR(srcSize_wrong);
3472                 nbSeq = ((nbSeq-0x80)<<8) + *ip++;
3473             }
3474         }
3475         *nbSeqPtr = nbSeq;
3476     }
3477 
3478     /* FSE table descriptors */
3479     if (ip + 4 > iend) return ERROR(srcSize_wrong); /* min : header byte + all 3 are "raw", hence no header, but at least xxLog bits per type */
3480     {   U32 const LLtype  = *ip >> 6;
3481         U32 const OFtype = (*ip >> 4) & 3;
3482         U32 const MLtype  = (*ip >> 2) & 3;
3483         ip++;
3484 
3485         /* Build DTables */
3486         {   size_t const llhSize = ZSTDv07_buildSeqTable(DTableLL, LLtype, MaxLL, LLFSELog, ip, iend-ip, LL_defaultNorm, LL_defaultNormLog, flagRepeatTable);
3487             if (ZSTDv07_isError(llhSize)) return ERROR(corruption_detected);
3488             ip += llhSize;
3489         }
3490         {   size_t const ofhSize = ZSTDv07_buildSeqTable(DTableOffb, OFtype, MaxOff, OffFSELog, ip, iend-ip, OF_defaultNorm, OF_defaultNormLog, flagRepeatTable);
3491             if (ZSTDv07_isError(ofhSize)) return ERROR(corruption_detected);
3492             ip += ofhSize;
3493         }
3494         {   size_t const mlhSize = ZSTDv07_buildSeqTable(DTableML, MLtype, MaxML, MLFSELog, ip, iend-ip, ML_defaultNorm, ML_defaultNormLog, flagRepeatTable);
3495             if (ZSTDv07_isError(mlhSize)) return ERROR(corruption_detected);
3496             ip += mlhSize;
3497     }   }
3498 
3499     return ip-istart;
3500 }
3501 
3502 
3503 typedef struct {
3504     size_t litLength;
3505     size_t matchLength;
3506     size_t offset;
3507 } seq_t;
3508 
3509 typedef struct {
3510     BITv07_DStream_t DStream;
3511     FSEv07_DState_t stateLL;
3512     FSEv07_DState_t stateOffb;
3513     FSEv07_DState_t stateML;
3514     size_t prevOffset[ZSTDv07_REP_INIT];
3515 } seqState_t;
3516 
3517 
3518 static seq_t ZSTDv07_decodeSequence(seqState_t* seqState)
3519 {
3520     seq_t seq;
3521 
3522     U32 const llCode = FSEv07_peekSymbol(&(seqState->stateLL));
3523     U32 const mlCode = FSEv07_peekSymbol(&(seqState->stateML));
3524     U32 const ofCode = FSEv07_peekSymbol(&(seqState->stateOffb));   /* <= maxOff, by table construction */
3525 
3526     U32 const llBits = LL_bits[llCode];
3527     U32 const mlBits = ML_bits[mlCode];
3528     U32 const ofBits = ofCode;
3529     U32 const totalBits = llBits+mlBits+ofBits;
3530 
3531     static const U32 LL_base[MaxLL+1] = {
3532                              0,  1,  2,  3,  4,  5,  6,  7,  8,  9,   10,    11,    12,    13,    14,     15,
3533                             16, 18, 20, 22, 24, 28, 32, 40, 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
3534                             0x2000, 0x4000, 0x8000, 0x10000 };
3535 
3536     static const U32 ML_base[MaxML+1] = {
3537                              3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13,   14,    15,    16,    17,    18,
3538                             19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,   30,    31,    32,    33,    34,
3539                             35, 37, 39, 41, 43, 47, 51, 59, 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
3540                             0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };
3541 
3542     static const U32 OF_base[MaxOff+1] = {
3543                  0,        1,       1,       5,     0xD,     0x1D,     0x3D,     0x7D,
3544                  0xFD,   0x1FD,   0x3FD,   0x7FD,   0xFFD,   0x1FFD,   0x3FFD,   0x7FFD,
3545                  0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
3546                  0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD };
3547 
3548     /* sequence */
3549     {   size_t offset;
3550         if (!ofCode)
3551             offset = 0;
3552         else {
3553             offset = OF_base[ofCode] + BITv07_readBits(&(seqState->DStream), ofBits);   /* <=  (ZSTDv07_WINDOWLOG_MAX-1) bits */
3554             if (MEM_32bits()) BITv07_reloadDStream(&(seqState->DStream));
3555         }
3556 
3557         if (ofCode <= 1) {
3558             if ((llCode == 0) & (offset <= 1)) offset = 1-offset;
3559             if (offset) {
3560                 size_t const temp = seqState->prevOffset[offset];
3561                 if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
3562                 seqState->prevOffset[1] = seqState->prevOffset[0];
3563                 seqState->prevOffset[0] = offset = temp;
3564             } else {
3565                 offset = seqState->prevOffset[0];
3566             }
3567         } else {
3568             seqState->prevOffset[2] = seqState->prevOffset[1];
3569             seqState->prevOffset[1] = seqState->prevOffset[0];
3570             seqState->prevOffset[0] = offset;
3571         }
3572         seq.offset = offset;
3573     }
3574 
3575     seq.matchLength = ML_base[mlCode] + ((mlCode>31) ? BITv07_readBits(&(seqState->DStream), mlBits) : 0);   /* <=  16 bits */
3576     if (MEM_32bits() && (mlBits+llBits>24)) BITv07_reloadDStream(&(seqState->DStream));
3577 
3578     seq.litLength = LL_base[llCode] + ((llCode>15) ? BITv07_readBits(&(seqState->DStream), llBits) : 0);   /* <=  16 bits */
3579     if (MEM_32bits() ||
3580        (totalBits > 64 - 7 - (LLFSELog+MLFSELog+OffFSELog)) ) BITv07_reloadDStream(&(seqState->DStream));
3581 
3582     /* ANS state update */
3583     FSEv07_updateState(&(seqState->stateLL), &(seqState->DStream));   /* <=  9 bits */
3584     FSEv07_updateState(&(seqState->stateML), &(seqState->DStream));   /* <=  9 bits */
3585     if (MEM_32bits()) BITv07_reloadDStream(&(seqState->DStream));     /* <= 18 bits */
3586     FSEv07_updateState(&(seqState->stateOffb), &(seqState->DStream)); /* <=  8 bits */
3587 
3588     return seq;
3589 }
3590 
3591 
3592 static
3593 size_t ZSTDv07_execSequence(BYTE* op,
3594                                 BYTE* const oend, seq_t sequence,
3595                                 const BYTE** litPtr, const BYTE* const litLimit,
3596                                 const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
3597 {
3598     BYTE* const oLitEnd = op + sequence.litLength;
3599     size_t const sequenceLength = sequence.litLength + sequence.matchLength;
3600     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
3601     BYTE* const oend_w = oend-WILDCOPY_OVERLENGTH;
3602     const BYTE* const iLitEnd = *litPtr + sequence.litLength;
3603     const BYTE* match = oLitEnd - sequence.offset;
3604 
3605     /* check */
3606     if ((oLitEnd>oend_w) | (oMatchEnd>oend)) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
3607     if (iLitEnd > litLimit) return ERROR(corruption_detected);   /* over-read beyond lit buffer */
3608 
3609     /* copy Literals */
3610     ZSTDv07_wildcopy(op, *litPtr, sequence.litLength);   /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
3611     op = oLitEnd;
3612     *litPtr = iLitEnd;   /* update for next sequence */
3613 
3614     /* copy Match */
3615     if (sequence.offset > (size_t)(oLitEnd - base)) {
3616         /* offset beyond prefix */
3617         if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(corruption_detected);
3618         match = dictEnd - (base-match);
3619         if (match + sequence.matchLength <= dictEnd) {
3620             memmove(oLitEnd, match, sequence.matchLength);
3621             return sequenceLength;
3622         }
3623         /* span extDict & currentPrefixSegment */
3624         {   size_t const length1 = dictEnd - match;
3625             memmove(oLitEnd, match, length1);
3626             op = oLitEnd + length1;
3627             sequence.matchLength -= length1;
3628             match = base;
3629             if (op > oend_w || sequence.matchLength < MINMATCH) {
3630               while (op < oMatchEnd) *op++ = *match++;
3631               return sequenceLength;
3632             }
3633     }   }
3634     /* Requirement: op <= oend_w */
3635 
3636     /* match within prefix */
3637     if (sequence.offset < 8) {
3638         /* close range match, overlap */
3639         static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
3640         static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
3641         int const sub2 = dec64table[sequence.offset];
3642         op[0] = match[0];
3643         op[1] = match[1];
3644         op[2] = match[2];
3645         op[3] = match[3];
3646         match += dec32table[sequence.offset];
3647         ZSTDv07_copy4(op+4, match);
3648         match -= sub2;
3649     } else {
3650         ZSTDv07_copy8(op, match);
3651     }
3652     op += 8; match += 8;
3653 
3654     if (oMatchEnd > oend-(16-MINMATCH)) {
3655         if (op < oend_w) {
3656             ZSTDv07_wildcopy(op, match, oend_w - op);
3657             match += oend_w - op;
3658             op = oend_w;
3659         }
3660         while (op < oMatchEnd) *op++ = *match++;
3661     } else {
3662         ZSTDv07_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
3663     }
3664     return sequenceLength;
3665 }
3666 
3667 
3668 static size_t ZSTDv07_decompressSequences(
3669                                ZSTDv07_DCtx* dctx,
3670                                void* dst, size_t maxDstSize,
3671                          const void* seqStart, size_t seqSize)
3672 {
3673     const BYTE* ip = (const BYTE*)seqStart;
3674     const BYTE* const iend = ip + seqSize;
3675     BYTE* const ostart = (BYTE* const)dst;
3676     BYTE* const oend = ostart + maxDstSize;
3677     BYTE* op = ostart;
3678     const BYTE* litPtr = dctx->litPtr;
3679     const BYTE* const litEnd = litPtr + dctx->litSize;
3680     FSEv07_DTable* DTableLL = dctx->LLTable;
3681     FSEv07_DTable* DTableML = dctx->MLTable;
3682     FSEv07_DTable* DTableOffb = dctx->OffTable;
3683     const BYTE* const base = (const BYTE*) (dctx->base);
3684     const BYTE* const vBase = (const BYTE*) (dctx->vBase);
3685     const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
3686     int nbSeq;
3687 
3688     /* Build Decoding Tables */
3689     {   size_t const seqHSize = ZSTDv07_decodeSeqHeaders(&nbSeq, DTableLL, DTableML, DTableOffb, dctx->fseEntropy, ip, seqSize);
3690         if (ZSTDv07_isError(seqHSize)) return seqHSize;
3691         ip += seqHSize;
3692     }
3693 
3694     /* Regen sequences */
3695     if (nbSeq) {
3696         seqState_t seqState;
3697         dctx->fseEntropy = 1;
3698         { U32 i; for (i=0; i<ZSTDv07_REP_INIT; i++) seqState.prevOffset[i] = dctx->rep[i]; }
3699         { size_t const errorCode = BITv07_initDStream(&(seqState.DStream), ip, iend-ip);
3700           if (ERR_isError(errorCode)) return ERROR(corruption_detected); }
3701         FSEv07_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
3702         FSEv07_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
3703         FSEv07_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
3704 
3705         for ( ; (BITv07_reloadDStream(&(seqState.DStream)) <= BITv07_DStream_completed) && nbSeq ; ) {
3706             nbSeq--;
3707             {   seq_t const sequence = ZSTDv07_decodeSequence(&seqState);
3708                 size_t const oneSeqSize = ZSTDv07_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
3709                 if (ZSTDv07_isError(oneSeqSize)) return oneSeqSize;
3710                 op += oneSeqSize;
3711         }   }
3712 
3713         /* check if reached exact end */
3714         if (nbSeq) return ERROR(corruption_detected);
3715         /* save reps for next block */
3716         { U32 i; for (i=0; i<ZSTDv07_REP_INIT; i++) dctx->rep[i] = (U32)(seqState.prevOffset[i]); }
3717     }
3718 
3719     /* last literal segment */
3720     {   size_t const lastLLSize = litEnd - litPtr;
3721         /* if (litPtr > litEnd) return ERROR(corruption_detected); */   /* too many literals already used */
3722         if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall);
3723         if (lastLLSize > 0) {
3724             memcpy(op, litPtr, lastLLSize);
3725             op += lastLLSize;
3726         }
3727     }
3728 
3729     return op-ostart;
3730 }
3731 
3732 
3733 static void ZSTDv07_checkContinuity(ZSTDv07_DCtx* dctx, const void* dst)
3734 {
3735     if (dst != dctx->previousDstEnd) {   /* not contiguous */
3736         dctx->dictEnd = dctx->previousDstEnd;
3737         dctx->vBase = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
3738         dctx->base = dst;
3739         dctx->previousDstEnd = dst;
3740     }
3741 }
3742 
3743 
3744 static size_t ZSTDv07_decompressBlock_internal(ZSTDv07_DCtx* dctx,
3745                             void* dst, size_t dstCapacity,
3746                       const void* src, size_t srcSize)
3747 {   /* blockType == blockCompressed */
3748     const BYTE* ip = (const BYTE*)src;
3749 
3750     if (srcSize >= ZSTDv07_BLOCKSIZE_ABSOLUTEMAX) return ERROR(srcSize_wrong);
3751 
3752     /* Decode literals sub-block */
3753     {   size_t const litCSize = ZSTDv07_decodeLiteralsBlock(dctx, src, srcSize);
3754         if (ZSTDv07_isError(litCSize)) return litCSize;
3755         ip += litCSize;
3756         srcSize -= litCSize;
3757     }
3758     return ZSTDv07_decompressSequences(dctx, dst, dstCapacity, ip, srcSize);
3759 }
3760 
3761 
3762 size_t ZSTDv07_decompressBlock(ZSTDv07_DCtx* dctx,
3763                             void* dst, size_t dstCapacity,
3764                       const void* src, size_t srcSize)
3765 {
3766     size_t dSize;
3767     ZSTDv07_checkContinuity(dctx, dst);
3768     dSize = ZSTDv07_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize);
3769     dctx->previousDstEnd = (char*)dst + dSize;
3770     return dSize;
3771 }
3772 
3773 
3774 /** ZSTDv07_insertBlock() :
3775     insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
3776 ZSTDLIBv07_API size_t ZSTDv07_insertBlock(ZSTDv07_DCtx* dctx, const void* blockStart, size_t blockSize)
3777 {
3778     ZSTDv07_checkContinuity(dctx, blockStart);
3779     dctx->previousDstEnd = (const char*)blockStart + blockSize;
3780     return blockSize;
3781 }
3782 
3783 
3784 static size_t ZSTDv07_generateNxBytes(void* dst, size_t dstCapacity, BYTE byte, size_t length)
3785 {
3786     if (length > dstCapacity) return ERROR(dstSize_tooSmall);
3787     if (length > 0) {
3788         memset(dst, byte, length);
3789     }
3790     return length;
3791 }
3792 
3793 
3794 /*! ZSTDv07_decompressFrame() :
3795 *   `dctx` must be properly initialized */
3796 static size_t ZSTDv07_decompressFrame(ZSTDv07_DCtx* dctx,
3797                                  void* dst, size_t dstCapacity,
3798                                  const void* src, size_t srcSize)
3799 {
3800     const BYTE* ip = (const BYTE*)src;
3801     const BYTE* const iend = ip + srcSize;
3802     BYTE* const ostart = (BYTE* const)dst;
3803     BYTE* const oend = ostart + dstCapacity;
3804     BYTE* op = ostart;
3805     size_t remainingSize = srcSize;
3806 
3807     /* check */
3808     if (srcSize < ZSTDv07_frameHeaderSize_min+ZSTDv07_blockHeaderSize) return ERROR(srcSize_wrong);
3809 
3810     /* Frame Header */
3811     {   size_t const frameHeaderSize = ZSTDv07_frameHeaderSize(src, ZSTDv07_frameHeaderSize_min);
3812         if (ZSTDv07_isError(frameHeaderSize)) return frameHeaderSize;
3813         if (srcSize < frameHeaderSize+ZSTDv07_blockHeaderSize) return ERROR(srcSize_wrong);
3814         if (ZSTDv07_decodeFrameHeader(dctx, src, frameHeaderSize)) return ERROR(corruption_detected);
3815         ip += frameHeaderSize; remainingSize -= frameHeaderSize;
3816     }
3817 
3818     /* Loop on each block */
3819     while (1) {
3820         size_t decodedSize;
3821         blockProperties_t blockProperties;
3822         size_t const cBlockSize = ZSTDv07_getcBlockSize(ip, iend-ip, &blockProperties);
3823         if (ZSTDv07_isError(cBlockSize)) return cBlockSize;
3824 
3825         ip += ZSTDv07_blockHeaderSize;
3826         remainingSize -= ZSTDv07_blockHeaderSize;
3827         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
3828 
3829         switch(blockProperties.blockType)
3830         {
3831         case bt_compressed:
3832             decodedSize = ZSTDv07_decompressBlock_internal(dctx, op, oend-op, ip, cBlockSize);
3833             break;
3834         case bt_raw :
3835             decodedSize = ZSTDv07_copyRawBlock(op, oend-op, ip, cBlockSize);
3836             break;
3837         case bt_rle :
3838             decodedSize = ZSTDv07_generateNxBytes(op, oend-op, *ip, blockProperties.origSize);
3839             break;
3840         case bt_end :
3841             /* end of frame */
3842             if (remainingSize) return ERROR(srcSize_wrong);
3843             decodedSize = 0;
3844             break;
3845         default:
3846             return ERROR(GENERIC);   /* impossible */
3847         }
3848         if (blockProperties.blockType == bt_end) break;   /* bt_end */
3849 
3850         if (ZSTDv07_isError(decodedSize)) return decodedSize;
3851         if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, op, decodedSize);
3852         op += decodedSize;
3853         ip += cBlockSize;
3854         remainingSize -= cBlockSize;
3855     }
3856 
3857     return op-ostart;
3858 }
3859 
3860 
3861 /*! ZSTDv07_decompress_usingPreparedDCtx() :
3862 *   Same as ZSTDv07_decompress_usingDict, but using a reference context `preparedDCtx`, where dictionary has been loaded.
3863 *   It avoids reloading the dictionary each time.
3864 *   `preparedDCtx` must have been properly initialized using ZSTDv07_decompressBegin_usingDict().
3865 *   Requires 2 contexts : 1 for reference (preparedDCtx), which will not be modified, and 1 to run the decompression operation (dctx) */
3866 static size_t ZSTDv07_decompress_usingPreparedDCtx(ZSTDv07_DCtx* dctx, const ZSTDv07_DCtx* refDCtx,
3867                                          void* dst, size_t dstCapacity,
3868                                    const void* src, size_t srcSize)
3869 {
3870     ZSTDv07_copyDCtx(dctx, refDCtx);
3871     ZSTDv07_checkContinuity(dctx, dst);
3872     return ZSTDv07_decompressFrame(dctx, dst, dstCapacity, src, srcSize);
3873 }
3874 
3875 
3876 size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx,
3877                                  void* dst, size_t dstCapacity,
3878                                  const void* src, size_t srcSize,
3879                                  const void* dict, size_t dictSize)
3880 {
3881     ZSTDv07_decompressBegin_usingDict(dctx, dict, dictSize);
3882     ZSTDv07_checkContinuity(dctx, dst);
3883     return ZSTDv07_decompressFrame(dctx, dst, dstCapacity, src, srcSize);
3884 }
3885 
3886 
3887 size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
3888 {
3889     return ZSTDv07_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0);
3890 }
3891 
3892 
3893 size_t ZSTDv07_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
3894 {
3895 #if defined(ZSTDv07_HEAPMODE) && (ZSTDv07_HEAPMODE==1)
3896     size_t regenSize;
3897     ZSTDv07_DCtx* const dctx = ZSTDv07_createDCtx();
3898     if (dctx==NULL) return ERROR(memory_allocation);
3899     regenSize = ZSTDv07_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
3900     ZSTDv07_freeDCtx(dctx);
3901     return regenSize;
3902 #else   /* stack mode */
3903     ZSTDv07_DCtx dctx;
3904     return ZSTDv07_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
3905 #endif
3906 }
3907 
3908 /* ZSTD_errorFrameSizeInfoLegacy() :
3909    assumes `cSize` and `dBound` are _not_ NULL */
3910 static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
3911 {
3912     *cSize = ret;
3913     *dBound = ZSTD_CONTENTSIZE_ERROR;
3914 }
3915 
3916 void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
3917 {
3918     const BYTE* ip = (const BYTE*)src;
3919     size_t remainingSize = srcSize;
3920     size_t nbBlocks = 0;
3921 
3922     /* check */
3923     if (srcSize < ZSTDv07_frameHeaderSize_min+ZSTDv07_blockHeaderSize) {
3924         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3925         return;
3926     }
3927 
3928     /* Frame Header */
3929     {   size_t const frameHeaderSize = ZSTDv07_frameHeaderSize(src, srcSize);
3930         if (ZSTDv07_isError(frameHeaderSize)) {
3931             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, frameHeaderSize);
3932             return;
3933         }
3934         if (MEM_readLE32(src) != ZSTDv07_MAGICNUMBER) {
3935             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
3936             return;
3937         }
3938         if (srcSize < frameHeaderSize+ZSTDv07_blockHeaderSize) {
3939             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3940             return;
3941         }
3942         ip += frameHeaderSize; remainingSize -= frameHeaderSize;
3943     }
3944 
3945     /* Loop on each block */
3946     while (1) {
3947         blockProperties_t blockProperties;
3948         size_t const cBlockSize = ZSTDv07_getcBlockSize(ip, remainingSize, &blockProperties);
3949         if (ZSTDv07_isError(cBlockSize)) {
3950             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
3951             return;
3952         }
3953 
3954         ip += ZSTDv07_blockHeaderSize;
3955         remainingSize -= ZSTDv07_blockHeaderSize;
3956 
3957         if (blockProperties.blockType == bt_end) break;
3958 
3959         if (cBlockSize > remainingSize) {
3960             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3961             return;
3962         }
3963 
3964         ip += cBlockSize;
3965         remainingSize -= cBlockSize;
3966         nbBlocks++;
3967     }
3968 
3969     *cSize = ip - (const BYTE*)src;
3970     *dBound = nbBlocks * ZSTDv07_BLOCKSIZE_ABSOLUTEMAX;
3971 }
3972 
3973 /*_******************************
3974 *  Streaming Decompression API
3975 ********************************/
3976 size_t ZSTDv07_nextSrcSizeToDecompress(ZSTDv07_DCtx* dctx)
3977 {
3978     return dctx->expected;
3979 }
3980 
3981 int ZSTDv07_isSkipFrame(ZSTDv07_DCtx* dctx)
3982 {
3983     return dctx->stage == ZSTDds_skipFrame;
3984 }
3985 
3986 /** ZSTDv07_decompressContinue() :
3987 *   @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
3988 *             or an error code, which can be tested using ZSTDv07_isError() */
3989 size_t ZSTDv07_decompressContinue(ZSTDv07_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
3990 {
3991     /* Sanity check */
3992     if (srcSize != dctx->expected) return ERROR(srcSize_wrong);
3993     if (dstCapacity) ZSTDv07_checkContinuity(dctx, dst);
3994 
3995     switch (dctx->stage)
3996     {
3997     case ZSTDds_getFrameHeaderSize :
3998         if (srcSize != ZSTDv07_frameHeaderSize_min) return ERROR(srcSize_wrong);   /* impossible */
3999         if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTDv07_MAGIC_SKIPPABLE_START) {
4000             memcpy(dctx->headerBuffer, src, ZSTDv07_frameHeaderSize_min);
4001             dctx->expected = ZSTDv07_skippableHeaderSize - ZSTDv07_frameHeaderSize_min; /* magic number + skippable frame length */
4002             dctx->stage = ZSTDds_decodeSkippableHeader;
4003             return 0;
4004         }
4005         dctx->headerSize = ZSTDv07_frameHeaderSize(src, ZSTDv07_frameHeaderSize_min);
4006         if (ZSTDv07_isError(dctx->headerSize)) return dctx->headerSize;
4007         memcpy(dctx->headerBuffer, src, ZSTDv07_frameHeaderSize_min);
4008         if (dctx->headerSize > ZSTDv07_frameHeaderSize_min) {
4009             dctx->expected = dctx->headerSize - ZSTDv07_frameHeaderSize_min;
4010             dctx->stage = ZSTDds_decodeFrameHeader;
4011             return 0;
4012         }
4013         dctx->expected = 0;   /* not necessary to copy more */
4014 	/* fall-through */
4015     case ZSTDds_decodeFrameHeader:
4016         {   size_t result;
4017             memcpy(dctx->headerBuffer + ZSTDv07_frameHeaderSize_min, src, dctx->expected);
4018             result = ZSTDv07_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize);
4019             if (ZSTDv07_isError(result)) return result;
4020             dctx->expected = ZSTDv07_blockHeaderSize;
4021             dctx->stage = ZSTDds_decodeBlockHeader;
4022             return 0;
4023         }
4024     case ZSTDds_decodeBlockHeader:
4025         {   blockProperties_t bp;
4026             size_t const cBlockSize = ZSTDv07_getcBlockSize(src, ZSTDv07_blockHeaderSize, &bp);
4027             if (ZSTDv07_isError(cBlockSize)) return cBlockSize;
4028             if (bp.blockType == bt_end) {
4029                 if (dctx->fParams.checksumFlag) {
4030                     U64 const h64 = XXH64_digest(&dctx->xxhState);
4031                     U32 const h32 = (U32)(h64>>11) & ((1<<22)-1);
4032                     const BYTE* const ip = (const BYTE*)src;
4033                     U32 const check32 = ip[2] + (ip[1] << 8) + ((ip[0] & 0x3F) << 16);
4034                     if (check32 != h32) return ERROR(checksum_wrong);
4035                 }
4036                 dctx->expected = 0;
4037                 dctx->stage = ZSTDds_getFrameHeaderSize;
4038             } else {
4039                 dctx->expected = cBlockSize;
4040                 dctx->bType = bp.blockType;
4041                 dctx->stage = ZSTDds_decompressBlock;
4042             }
4043             return 0;
4044         }
4045     case ZSTDds_decompressBlock:
4046         {   size_t rSize;
4047             switch(dctx->bType)
4048             {
4049             case bt_compressed:
4050                 rSize = ZSTDv07_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize);
4051                 break;
4052             case bt_raw :
4053                 rSize = ZSTDv07_copyRawBlock(dst, dstCapacity, src, srcSize);
4054                 break;
4055             case bt_rle :
4056                 return ERROR(GENERIC);   /* not yet handled */
4057                 break;
4058             case bt_end :   /* should never happen (filtered at phase 1) */
4059                 rSize = 0;
4060                 break;
4061             default:
4062                 return ERROR(GENERIC);   /* impossible */
4063             }
4064             dctx->stage = ZSTDds_decodeBlockHeader;
4065             dctx->expected = ZSTDv07_blockHeaderSize;
4066             dctx->previousDstEnd = (char*)dst + rSize;
4067             if (ZSTDv07_isError(rSize)) return rSize;
4068             if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize);
4069             return rSize;
4070         }
4071     case ZSTDds_decodeSkippableHeader:
4072         {   memcpy(dctx->headerBuffer + ZSTDv07_frameHeaderSize_min, src, dctx->expected);
4073             dctx->expected = MEM_readLE32(dctx->headerBuffer + 4);
4074             dctx->stage = ZSTDds_skipFrame;
4075             return 0;
4076         }
4077     case ZSTDds_skipFrame:
4078         {   dctx->expected = 0;
4079             dctx->stage = ZSTDds_getFrameHeaderSize;
4080             return 0;
4081         }
4082     default:
4083         return ERROR(GENERIC);   /* impossible */
4084     }
4085 }
4086 
4087 
4088 static size_t ZSTDv07_refDictContent(ZSTDv07_DCtx* dctx, const void* dict, size_t dictSize)
4089 {
4090     dctx->dictEnd = dctx->previousDstEnd;
4091     dctx->vBase = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
4092     dctx->base = dict;
4093     dctx->previousDstEnd = (const char*)dict + dictSize;
4094     return 0;
4095 }
4096 
4097 static size_t ZSTDv07_loadEntropy(ZSTDv07_DCtx* dctx, const void* const dict, size_t const dictSize)
4098 {
4099     const BYTE* dictPtr = (const BYTE*)dict;
4100     const BYTE* const dictEnd = dictPtr + dictSize;
4101 
4102     {   size_t const hSize = HUFv07_readDTableX4(dctx->hufTable, dict, dictSize);
4103         if (HUFv07_isError(hSize)) return ERROR(dictionary_corrupted);
4104         dictPtr += hSize;
4105     }
4106 
4107     {   short offcodeNCount[MaxOff+1];
4108         U32 offcodeMaxValue=MaxOff, offcodeLog;
4109         size_t const offcodeHeaderSize = FSEv07_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
4110         if (FSEv07_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted);
4111         if (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted);
4112         { size_t const errorCode = FSEv07_buildDTable(dctx->OffTable, offcodeNCount, offcodeMaxValue, offcodeLog);
4113           if (FSEv07_isError(errorCode)) return ERROR(dictionary_corrupted); }
4114         dictPtr += offcodeHeaderSize;
4115     }
4116 
4117     {   short matchlengthNCount[MaxML+1];
4118         unsigned matchlengthMaxValue = MaxML, matchlengthLog;
4119         size_t const matchlengthHeaderSize = FSEv07_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
4120         if (FSEv07_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted);
4121         if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted);
4122         { size_t const errorCode = FSEv07_buildDTable(dctx->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog);
4123           if (FSEv07_isError(errorCode)) return ERROR(dictionary_corrupted); }
4124         dictPtr += matchlengthHeaderSize;
4125     }
4126 
4127     {   short litlengthNCount[MaxLL+1];
4128         unsigned litlengthMaxValue = MaxLL, litlengthLog;
4129         size_t const litlengthHeaderSize = FSEv07_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
4130         if (FSEv07_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted);
4131         if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted);
4132         { size_t const errorCode = FSEv07_buildDTable(dctx->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog);
4133           if (FSEv07_isError(errorCode)) return ERROR(dictionary_corrupted); }
4134         dictPtr += litlengthHeaderSize;
4135     }
4136 
4137     if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
4138     dctx->rep[0] = MEM_readLE32(dictPtr+0); if (dctx->rep[0] == 0 || dctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
4139     dctx->rep[1] = MEM_readLE32(dictPtr+4); if (dctx->rep[1] == 0 || dctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
4140     dctx->rep[2] = MEM_readLE32(dictPtr+8); if (dctx->rep[2] == 0 || dctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
4141     dictPtr += 12;
4142 
4143     dctx->litEntropy = dctx->fseEntropy = 1;
4144     return dictPtr - (const BYTE*)dict;
4145 }
4146 
4147 static size_t ZSTDv07_decompress_insertDictionary(ZSTDv07_DCtx* dctx, const void* dict, size_t dictSize)
4148 {
4149     if (dictSize < 8) return ZSTDv07_refDictContent(dctx, dict, dictSize);
4150     {   U32 const magic = MEM_readLE32(dict);
4151         if (magic != ZSTDv07_DICT_MAGIC) {
4152             return ZSTDv07_refDictContent(dctx, dict, dictSize);   /* pure content mode */
4153     }   }
4154     dctx->dictID = MEM_readLE32((const char*)dict + 4);
4155 
4156     /* load entropy tables */
4157     dict = (const char*)dict + 8;
4158     dictSize -= 8;
4159     {   size_t const eSize = ZSTDv07_loadEntropy(dctx, dict, dictSize);
4160         if (ZSTDv07_isError(eSize)) return ERROR(dictionary_corrupted);
4161         dict = (const char*)dict + eSize;
4162         dictSize -= eSize;
4163     }
4164 
4165     /* reference dictionary content */
4166     return ZSTDv07_refDictContent(dctx, dict, dictSize);
4167 }
4168 
4169 
4170 size_t ZSTDv07_decompressBegin_usingDict(ZSTDv07_DCtx* dctx, const void* dict, size_t dictSize)
4171 {
4172     { size_t const errorCode = ZSTDv07_decompressBegin(dctx);
4173       if (ZSTDv07_isError(errorCode)) return errorCode; }
4174 
4175     if (dict && dictSize) {
4176         size_t const errorCode = ZSTDv07_decompress_insertDictionary(dctx, dict, dictSize);
4177         if (ZSTDv07_isError(errorCode)) return ERROR(dictionary_corrupted);
4178     }
4179 
4180     return 0;
4181 }
4182 
4183 
4184 struct ZSTDv07_DDict_s {
4185     void* dict;
4186     size_t dictSize;
4187     ZSTDv07_DCtx* refContext;
4188 };  /* typedef'd tp ZSTDv07_CDict within zstd.h */
4189 
4190 static ZSTDv07_DDict* ZSTDv07_createDDict_advanced(const void* dict, size_t dictSize, ZSTDv07_customMem customMem)
4191 {
4192     if (!customMem.customAlloc && !customMem.customFree)
4193         customMem = defaultCustomMem;
4194 
4195     if (!customMem.customAlloc || !customMem.customFree)
4196         return NULL;
4197 
4198     {   ZSTDv07_DDict* const ddict = (ZSTDv07_DDict*) customMem.customAlloc(customMem.opaque, sizeof(*ddict));
4199         void* const dictContent = customMem.customAlloc(customMem.opaque, dictSize);
4200         ZSTDv07_DCtx* const dctx = ZSTDv07_createDCtx_advanced(customMem);
4201 
4202         if (!dictContent || !ddict || !dctx) {
4203             customMem.customFree(customMem.opaque, dictContent);
4204             customMem.customFree(customMem.opaque, ddict);
4205             customMem.customFree(customMem.opaque, dctx);
4206             return NULL;
4207         }
4208 
4209         memcpy(dictContent, dict, dictSize);
4210         {   size_t const errorCode = ZSTDv07_decompressBegin_usingDict(dctx, dictContent, dictSize);
4211             if (ZSTDv07_isError(errorCode)) {
4212                 customMem.customFree(customMem.opaque, dictContent);
4213                 customMem.customFree(customMem.opaque, ddict);
4214                 customMem.customFree(customMem.opaque, dctx);
4215                 return NULL;
4216         }   }
4217 
4218         ddict->dict = dictContent;
4219         ddict->dictSize = dictSize;
4220         ddict->refContext = dctx;
4221         return ddict;
4222     }
4223 }
4224 
4225 /*! ZSTDv07_createDDict() :
4226 *   Create a digested dictionary, ready to start decompression without startup delay.
4227 *   `dict` can be released after `ZSTDv07_DDict` creation */
4228 ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize)
4229 {
4230     ZSTDv07_customMem const allocator = { NULL, NULL, NULL };
4231     return ZSTDv07_createDDict_advanced(dict, dictSize, allocator);
4232 }
4233 
4234 size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict)
4235 {
4236     ZSTDv07_freeFunction const cFree = ddict->refContext->customMem.customFree;
4237     void* const opaque = ddict->refContext->customMem.opaque;
4238     ZSTDv07_freeDCtx(ddict->refContext);
4239     cFree(opaque, ddict->dict);
4240     cFree(opaque, ddict);
4241     return 0;
4242 }
4243 
4244 /*! ZSTDv07_decompress_usingDDict() :
4245 *   Decompression using a pre-digested Dictionary
4246 *   Use dictionary without significant overhead. */
4247 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx,
4248                                            void* dst, size_t dstCapacity,
4249                                      const void* src, size_t srcSize,
4250                                      const ZSTDv07_DDict* ddict)
4251 {
4252     return ZSTDv07_decompress_usingPreparedDCtx(dctx, ddict->refContext,
4253                                            dst, dstCapacity,
4254                                            src, srcSize);
4255 }
4256 /*
4257     Buffered version of Zstd compression library
4258     Copyright (C) 2015-2016, Yann Collet.
4259 
4260     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
4261 
4262     Redistribution and use in source and binary forms, with or without
4263     modification, are permitted provided that the following conditions are
4264     met:
4265     * Redistributions of source code must retain the above copyright
4266     notice, this list of conditions and the following disclaimer.
4267     * Redistributions in binary form must reproduce the above
4268     copyright notice, this list of conditions and the following disclaimer
4269     in the documentation and/or other materials provided with the
4270     distribution.
4271     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
4272     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
4273     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
4274     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
4275     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
4276     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
4277     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
4278     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
4279     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
4280     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
4281     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
4282 
4283     You can contact the author at :
4284     - zstd homepage : http://www.zstd.net/
4285 */
4286 
4287 
4288 
4289 /*-***************************************************************************
4290 *  Streaming decompression howto
4291 *
4292 *  A ZBUFFv07_DCtx object is required to track streaming operations.
4293 *  Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources.
4294 *  Use ZBUFFv07_decompressInit() to start a new decompression operation,
4295 *   or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary.
4296 *  Note that ZBUFFv07_DCtx objects can be re-init multiple times.
4297 *
4298 *  Use ZBUFFv07_decompressContinue() repetitively to consume your input.
4299 *  *srcSizePtr and *dstCapacityPtr can be any size.
4300 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
4301 *  Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
4302 *  The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change @dst.
4303 *  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
4304 *            or 0 when a frame is completely decoded,
4305 *            or an error code, which can be tested using ZBUFFv07_isError().
4306 *
4307 *  Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize()
4308 *  output : ZBUFFv07_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
4309 *  input  : ZBUFFv07_recommendedDInSize == 128KB + 3;
4310 *           just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
4311 * *******************************************************************************/
4312 
4313 typedef enum { ZBUFFds_init, ZBUFFds_loadHeader,
4314                ZBUFFds_read, ZBUFFds_load, ZBUFFds_flush } ZBUFFv07_dStage;
4315 
4316 /* *** Resource management *** */
4317 struct ZBUFFv07_DCtx_s {
4318     ZSTDv07_DCtx* zd;
4319     ZSTDv07_frameParams fParams;
4320     ZBUFFv07_dStage stage;
4321     char*  inBuff;
4322     size_t inBuffSize;
4323     size_t inPos;
4324     char*  outBuff;
4325     size_t outBuffSize;
4326     size_t outStart;
4327     size_t outEnd;
4328     size_t blockSize;
4329     BYTE headerBuffer[ZSTDv07_FRAMEHEADERSIZE_MAX];
4330     size_t lhSize;
4331     ZSTDv07_customMem customMem;
4332 };   /* typedef'd to ZBUFFv07_DCtx within "zstd_buffered.h" */
4333 
4334 ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx_advanced(ZSTDv07_customMem customMem);
4335 
4336 ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void)
4337 {
4338     return ZBUFFv07_createDCtx_advanced(defaultCustomMem);
4339 }
4340 
4341 ZBUFFv07_DCtx* ZBUFFv07_createDCtx_advanced(ZSTDv07_customMem customMem)
4342 {
4343     ZBUFFv07_DCtx* zbd;
4344 
4345     if (!customMem.customAlloc && !customMem.customFree)
4346         customMem = defaultCustomMem;
4347 
4348     if (!customMem.customAlloc || !customMem.customFree)
4349         return NULL;
4350 
4351     zbd = (ZBUFFv07_DCtx*)customMem.customAlloc(customMem.opaque, sizeof(ZBUFFv07_DCtx));
4352     if (zbd==NULL) return NULL;
4353     memset(zbd, 0, sizeof(ZBUFFv07_DCtx));
4354     memcpy(&zbd->customMem, &customMem, sizeof(ZSTDv07_customMem));
4355     zbd->zd = ZSTDv07_createDCtx_advanced(customMem);
4356     if (zbd->zd == NULL) { ZBUFFv07_freeDCtx(zbd); return NULL; }
4357     zbd->stage = ZBUFFds_init;
4358     return zbd;
4359 }
4360 
4361 size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* zbd)
4362 {
4363     if (zbd==NULL) return 0;   /* support free on null */
4364     ZSTDv07_freeDCtx(zbd->zd);
4365     if (zbd->inBuff) zbd->customMem.customFree(zbd->customMem.opaque, zbd->inBuff);
4366     if (zbd->outBuff) zbd->customMem.customFree(zbd->customMem.opaque, zbd->outBuff);
4367     zbd->customMem.customFree(zbd->customMem.opaque, zbd);
4368     return 0;
4369 }
4370 
4371 
4372 /* *** Initialization *** */
4373 
4374 size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* zbd, const void* dict, size_t dictSize)
4375 {
4376     zbd->stage = ZBUFFds_loadHeader;
4377     zbd->lhSize = zbd->inPos = zbd->outStart = zbd->outEnd = 0;
4378     return ZSTDv07_decompressBegin_usingDict(zbd->zd, dict, dictSize);
4379 }
4380 
4381 size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* zbd)
4382 {
4383     return ZBUFFv07_decompressInitDictionary(zbd, NULL, 0);
4384 }
4385 
4386 
4387 /* internal util function */
4388 MEM_STATIC size_t ZBUFFv07_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
4389 {
4390     size_t const length = MIN(dstCapacity, srcSize);
4391     if (length > 0) {
4392         memcpy(dst, src, length);
4393     }
4394     return length;
4395 }
4396 
4397 
4398 /* *** Decompression *** */
4399 
4400 size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* zbd,
4401                                 void* dst, size_t* dstCapacityPtr,
4402                           const void* src, size_t* srcSizePtr)
4403 {
4404     const char* const istart = (const char*)src;
4405     const char* const iend = istart + *srcSizePtr;
4406     const char* ip = istart;
4407     char* const ostart = (char*)dst;
4408     char* const oend = ostart + *dstCapacityPtr;
4409     char* op = ostart;
4410     U32 notDone = 1;
4411 
4412     while (notDone) {
4413         switch(zbd->stage)
4414         {
4415         case ZBUFFds_init :
4416             return ERROR(init_missing);
4417 
4418         case ZBUFFds_loadHeader :
4419             {   size_t const hSize = ZSTDv07_getFrameParams(&(zbd->fParams), zbd->headerBuffer, zbd->lhSize);
4420                 if (ZSTDv07_isError(hSize)) return hSize;
4421                 if (hSize != 0) {
4422                     size_t const toLoad = hSize - zbd->lhSize;   /* if hSize!=0, hSize > zbd->lhSize */
4423                     if (toLoad > (size_t)(iend-ip)) {   /* not enough input to load full header */
4424                         memcpy(zbd->headerBuffer + zbd->lhSize, ip, iend-ip);
4425                         zbd->lhSize += iend-ip;
4426                         *dstCapacityPtr = 0;
4427                         return (hSize - zbd->lhSize) + ZSTDv07_blockHeaderSize;   /* remaining header bytes + next block header */
4428                     }
4429                     memcpy(zbd->headerBuffer + zbd->lhSize, ip, toLoad); zbd->lhSize = hSize; ip += toLoad;
4430                     break;
4431             }   }
4432 
4433             /* Consume header */
4434             {   size_t const h1Size = ZSTDv07_nextSrcSizeToDecompress(zbd->zd);  /* == ZSTDv07_frameHeaderSize_min */
4435                 size_t const h1Result = ZSTDv07_decompressContinue(zbd->zd, NULL, 0, zbd->headerBuffer, h1Size);
4436                 if (ZSTDv07_isError(h1Result)) return h1Result;
4437                 if (h1Size < zbd->lhSize) {   /* long header */
4438                     size_t const h2Size = ZSTDv07_nextSrcSizeToDecompress(zbd->zd);
4439                     size_t const h2Result = ZSTDv07_decompressContinue(zbd->zd, NULL, 0, zbd->headerBuffer+h1Size, h2Size);
4440                     if (ZSTDv07_isError(h2Result)) return h2Result;
4441             }   }
4442 
4443             zbd->fParams.windowSize = MAX(zbd->fParams.windowSize, 1U << ZSTDv07_WINDOWLOG_ABSOLUTEMIN);
4444 
4445             /* Frame header instruct buffer sizes */
4446             {   size_t const blockSize = MIN(zbd->fParams.windowSize, ZSTDv07_BLOCKSIZE_ABSOLUTEMAX);
4447                 zbd->blockSize = blockSize;
4448                 if (zbd->inBuffSize < blockSize) {
4449                     zbd->customMem.customFree(zbd->customMem.opaque, zbd->inBuff);
4450                     zbd->inBuffSize = blockSize;
4451                     zbd->inBuff = (char*)zbd->customMem.customAlloc(zbd->customMem.opaque, blockSize);
4452                     if (zbd->inBuff == NULL) return ERROR(memory_allocation);
4453                 }
4454                 {   size_t const neededOutSize = zbd->fParams.windowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
4455                     if (zbd->outBuffSize < neededOutSize) {
4456                         zbd->customMem.customFree(zbd->customMem.opaque, zbd->outBuff);
4457                         zbd->outBuffSize = neededOutSize;
4458                         zbd->outBuff = (char*)zbd->customMem.customAlloc(zbd->customMem.opaque, neededOutSize);
4459                         if (zbd->outBuff == NULL) return ERROR(memory_allocation);
4460             }   }   }
4461             zbd->stage = ZBUFFds_read;
4462             /* pass-through */
4463 	    /* fall-through */
4464         case ZBUFFds_read:
4465             {   size_t const neededInSize = ZSTDv07_nextSrcSizeToDecompress(zbd->zd);
4466                 if (neededInSize==0) {  /* end of frame */
4467                     zbd->stage = ZBUFFds_init;
4468                     notDone = 0;
4469                     break;
4470                 }
4471                 if ((size_t)(iend-ip) >= neededInSize) {  /* decode directly from src */
4472                     const int isSkipFrame = ZSTDv07_isSkipFrame(zbd->zd);
4473                     size_t const decodedSize = ZSTDv07_decompressContinue(zbd->zd,
4474                         zbd->outBuff + zbd->outStart, (isSkipFrame ? 0 : zbd->outBuffSize - zbd->outStart),
4475                         ip, neededInSize);
4476                     if (ZSTDv07_isError(decodedSize)) return decodedSize;
4477                     ip += neededInSize;
4478                     if (!decodedSize && !isSkipFrame) break;   /* this was just a header */
4479                     zbd->outEnd = zbd->outStart +  decodedSize;
4480                     zbd->stage = ZBUFFds_flush;
4481                     break;
4482                 }
4483                 if (ip==iend) { notDone = 0; break; }   /* no more input */
4484                 zbd->stage = ZBUFFds_load;
4485             }
4486 	    /* fall-through */
4487         case ZBUFFds_load:
4488             {   size_t const neededInSize = ZSTDv07_nextSrcSizeToDecompress(zbd->zd);
4489                 size_t const toLoad = neededInSize - zbd->inPos;   /* should always be <= remaining space within inBuff */
4490                 size_t loadedSize;
4491                 if (toLoad > zbd->inBuffSize - zbd->inPos) return ERROR(corruption_detected);   /* should never happen */
4492                 loadedSize = ZBUFFv07_limitCopy(zbd->inBuff + zbd->inPos, toLoad, ip, iend-ip);
4493                 ip += loadedSize;
4494                 zbd->inPos += loadedSize;
4495                 if (loadedSize < toLoad) { notDone = 0; break; }   /* not enough input, wait for more */
4496 
4497                 /* decode loaded input */
4498                 {  const int isSkipFrame = ZSTDv07_isSkipFrame(zbd->zd);
4499                    size_t const decodedSize = ZSTDv07_decompressContinue(zbd->zd,
4500                         zbd->outBuff + zbd->outStart, zbd->outBuffSize - zbd->outStart,
4501                         zbd->inBuff, neededInSize);
4502                     if (ZSTDv07_isError(decodedSize)) return decodedSize;
4503                     zbd->inPos = 0;   /* input is consumed */
4504                     if (!decodedSize && !isSkipFrame) { zbd->stage = ZBUFFds_read; break; }   /* this was just a header */
4505                     zbd->outEnd = zbd->outStart +  decodedSize;
4506                     zbd->stage = ZBUFFds_flush;
4507                     /* break; */
4508                     /* pass-through */
4509                 }
4510 	    }
4511 	    /* fall-through */
4512         case ZBUFFds_flush:
4513             {   size_t const toFlushSize = zbd->outEnd - zbd->outStart;
4514                 size_t const flushedSize = ZBUFFv07_limitCopy(op, oend-op, zbd->outBuff + zbd->outStart, toFlushSize);
4515                 op += flushedSize;
4516                 zbd->outStart += flushedSize;
4517                 if (flushedSize == toFlushSize) {
4518                     zbd->stage = ZBUFFds_read;
4519                     if (zbd->outStart + zbd->blockSize > zbd->outBuffSize)
4520                         zbd->outStart = zbd->outEnd = 0;
4521                     break;
4522                 }
4523                 /* cannot flush everything */
4524                 notDone = 0;
4525                 break;
4526             }
4527         default: return ERROR(GENERIC);   /* impossible */
4528     }   }
4529 
4530     /* result */
4531     *srcSizePtr = ip-istart;
4532     *dstCapacityPtr = op-ostart;
4533     {   size_t nextSrcSizeHint = ZSTDv07_nextSrcSizeToDecompress(zbd->zd);
4534         nextSrcSizeHint -= zbd->inPos;   /* already loaded*/
4535         return nextSrcSizeHint;
4536     }
4537 }
4538 
4539 
4540 
4541 /* *************************************
4542 *  Tool functions
4543 ***************************************/
4544 size_t ZBUFFv07_recommendedDInSize(void)  { return ZSTDv07_BLOCKSIZE_ABSOLUTEMAX + ZSTDv07_blockHeaderSize /* block header size*/ ; }
4545 size_t ZBUFFv07_recommendedDOutSize(void) { return ZSTDv07_BLOCKSIZE_ABSOLUTEMAX; }
4546