xref: /freebsd/sys/contrib/zstd/lib/legacy/zstd_v04.c (revision 5ff13fbc199bdf5f0572845351c68ee5ca828e71)
1 /*
2  * Copyright (c) Yann Collet, Facebook, Inc.
3  * All rights reserved.
4  *
5  * This source code is licensed under both the BSD-style license (found in the
6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7  * in the COPYING file in the root directory of this source tree).
8  * You may select, at your option, one of the above-listed licenses.
9  */
10 
11 
12  /******************************************
13  *  Includes
14  ******************************************/
15 #include <stddef.h>    /* size_t, ptrdiff_t */
16 #include <string.h>    /* memcpy */
17 
18 #include "zstd_v04.h"
19 #include "../common/error_private.h"
20 
21 
22 /* ******************************************************************
23  *   mem.h
24  *******************************************************************/
25 #ifndef MEM_H_MODULE
26 #define MEM_H_MODULE
27 
28 #if defined (__cplusplus)
29 extern "C" {
30 #endif
31 
32 
33 /******************************************
34 *  Compiler-specific
35 ******************************************/
36 #if defined(_MSC_VER)   /* Visual Studio */
37 #   include <stdlib.h>  /* _byteswap_ulong */
38 #   include <intrin.h>  /* _byteswap_* */
39 #endif
40 #if defined(__GNUC__)
41 #  define MEM_STATIC static __attribute__((unused))
42 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
43 #  define MEM_STATIC static inline
44 #elif defined(_MSC_VER)
45 #  define MEM_STATIC static __inline
46 #else
47 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
48 #endif
49 
50 
51 /****************************************************************
52 *  Basic Types
53 *****************************************************************/
54 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
55 # if defined(_AIX)
56 #  include <inttypes.h>
57 # else
58 #  include <stdint.h> /* intptr_t */
59 # endif
60   typedef  uint8_t BYTE;
61   typedef uint16_t U16;
62   typedef  int16_t S16;
63   typedef uint32_t U32;
64   typedef  int32_t S32;
65   typedef uint64_t U64;
66   typedef  int64_t S64;
67 #else
68   typedef unsigned char       BYTE;
69   typedef unsigned short      U16;
70   typedef   signed short      S16;
71   typedef unsigned int        U32;
72   typedef   signed int        S32;
73   typedef unsigned long long  U64;
74   typedef   signed long long  S64;
75 #endif
76 
77 
78 /*-*************************************
79 *  Debug
80 ***************************************/
81 #include "../common/debug.h"
82 #ifndef assert
83 #  define assert(condition) ((void)0)
84 #endif
85 
86 
87 /****************************************************************
88 *  Memory I/O
89 *****************************************************************/
90 /* MEM_FORCE_MEMORY_ACCESS
91  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
92  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
93  * The below switch allow to select different access method for improved performance.
94  * Method 0 (default) : use `memcpy()`. Safe and portable.
95  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
96  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
97  * Method 2 : direct access. This method is portable but violate C standard.
98  *            It can generate buggy code on targets generating assembly depending on alignment.
99  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
100  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
101  * Prefer these methods in priority order (0 > 1 > 2)
102  */
103 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
104 #  if defined(__INTEL_COMPILER) || defined(__GNUC__) || defined(__ICCARM__)
105 #    define MEM_FORCE_MEMORY_ACCESS 1
106 #  endif
107 #endif
108 
MEM_32bits(void)109 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
MEM_64bits(void)110 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
111 
MEM_isLittleEndian(void)112 MEM_STATIC unsigned MEM_isLittleEndian(void)
113 {
114     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
115     return one.c[0];
116 }
117 
118 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
119 
120 /* violates C standard on structure alignment.
121 Only use if no other choice to achieve best performance on target platform */
MEM_read16(const void * memPtr)122 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
MEM_read32(const void * memPtr)123 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
MEM_read64(const void * memPtr)124 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
125 
MEM_write16(void * memPtr,U16 value)126 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
127 
128 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
129 
130 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
131 /* currently only defined for gcc and icc */
132 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
133 
MEM_read16(const void * ptr)134 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
MEM_read32(const void * ptr)135 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
MEM_read64(const void * ptr)136 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
137 
MEM_write16(void * memPtr,U16 value)138 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
139 
140 #else
141 
142 /* default method, safe and standard.
143    can sometimes prove slower */
144 
MEM_read16(const void * memPtr)145 MEM_STATIC U16 MEM_read16(const void* memPtr)
146 {
147     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
148 }
149 
MEM_read32(const void * memPtr)150 MEM_STATIC U32 MEM_read32(const void* memPtr)
151 {
152     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
153 }
154 
MEM_read64(const void * memPtr)155 MEM_STATIC U64 MEM_read64(const void* memPtr)
156 {
157     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
158 }
159 
MEM_write16(void * memPtr,U16 value)160 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
161 {
162     memcpy(memPtr, &value, sizeof(value));
163 }
164 
165 #endif /* MEM_FORCE_MEMORY_ACCESS */
166 
167 
MEM_readLE16(const void * memPtr)168 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
169 {
170     if (MEM_isLittleEndian())
171         return MEM_read16(memPtr);
172     else
173     {
174         const BYTE* p = (const BYTE*)memPtr;
175         return (U16)(p[0] + (p[1]<<8));
176     }
177 }
178 
MEM_writeLE16(void * memPtr,U16 val)179 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
180 {
181     if (MEM_isLittleEndian())
182     {
183         MEM_write16(memPtr, val);
184     }
185     else
186     {
187         BYTE* p = (BYTE*)memPtr;
188         p[0] = (BYTE)val;
189         p[1] = (BYTE)(val>>8);
190     }
191 }
192 
MEM_readLE24(const void * memPtr)193 MEM_STATIC U32 MEM_readLE24(const void* memPtr)
194 {
195     return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
196 }
197 
MEM_readLE32(const void * memPtr)198 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
199 {
200     if (MEM_isLittleEndian())
201         return MEM_read32(memPtr);
202     else
203     {
204         const BYTE* p = (const BYTE*)memPtr;
205         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
206     }
207 }
208 
209 
MEM_readLE64(const void * memPtr)210 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
211 {
212     if (MEM_isLittleEndian())
213         return MEM_read64(memPtr);
214     else
215     {
216         const BYTE* p = (const BYTE*)memPtr;
217         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
218                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
219     }
220 }
221 
222 
MEM_readLEST(const void * memPtr)223 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
224 {
225     if (MEM_32bits())
226         return (size_t)MEM_readLE32(memPtr);
227     else
228         return (size_t)MEM_readLE64(memPtr);
229 }
230 
231 
232 #if defined (__cplusplus)
233 }
234 #endif
235 
236 #endif /* MEM_H_MODULE */
237 
238 /*
239     zstd - standard compression library
240     Header File for static linking only
241 */
242 #ifndef ZSTD_STATIC_H
243 #define ZSTD_STATIC_H
244 
245 
246 /* *************************************
247 *  Types
248 ***************************************/
249 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 11
250 
251 /** from faster to stronger */
252 typedef enum { ZSTD_fast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2, ZSTD_btlazy2 } ZSTD_strategy;
253 
254 typedef struct
255 {
256     U64 srcSize;       /* optional : tells how much bytes are present in the frame. Use 0 if not known. */
257     U32 windowLog;     /* largest match distance : larger == more compression, more memory needed during decompression */
258     U32 contentLog;    /* full search segment : larger == more compression, slower, more memory (useless for fast) */
259     U32 hashLog;       /* dispatch table : larger == more memory, faster */
260     U32 searchLog;     /* nb of searches : larger == more compression, slower */
261     U32 searchLength;  /* size of matches : larger == faster decompression, sometimes less compression */
262     ZSTD_strategy strategy;
263 } ZSTD_parameters;
264 
265 typedef ZSTDv04_Dctx ZSTD_DCtx;
266 
267 /* *************************************
268 *  Advanced functions
269 ***************************************/
270 /** ZSTD_decompress_usingDict
271 *   Same as ZSTD_decompressDCtx, using a Dictionary content as prefix
272 *   Note : dict can be NULL, in which case, it's equivalent to ZSTD_decompressDCtx() */
273 static size_t ZSTD_decompress_usingDict(ZSTD_DCtx* ctx,
274                                              void* dst, size_t maxDstSize,
275                                        const void* src, size_t srcSize,
276                                        const void* dict,size_t dictSize);
277 
278 
279 /* **************************************
280 *  Streaming functions (direct mode)
281 ****************************************/
282 static size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx);
283 static size_t ZSTD_getFrameParams(ZSTD_parameters* params, const void* src, size_t srcSize);
284 static void   ZSTD_decompress_insertDictionary(ZSTD_DCtx* ctx, const void* src, size_t srcSize);
285 
286 static size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
287 static size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize);
288 
289 /**
290   Streaming decompression, bufferless mode
291 
292   A ZSTD_DCtx object is required to track streaming operations.
293   Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
294   A ZSTD_DCtx object can be re-used multiple times. Use ZSTD_resetDCtx() to return to fresh status.
295 
296   First operation is to retrieve frame parameters, using ZSTD_getFrameParams().
297   This function doesn't consume its input. It needs enough input data to properly decode the frame header.
298   Objective is to retrieve *params.windowlog, to know minimum amount of memory required during decoding.
299   Result : 0 when successful, it means the ZSTD_parameters structure has been filled.
300            >0 : means there is not enough data into src. Provides the expected size to successfully decode header.
301            errorCode, which can be tested using ZSTD_isError() (For example, if it's not a ZSTD header)
302 
303   Then, you can optionally insert a dictionary.
304   This operation must mimic the compressor behavior, otherwise decompression will fail or be corrupted.
305 
306   Then it's possible to start decompression.
307   Use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
308   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
309   ZSTD_decompressContinue() requires this exact amount of bytes, or it will fail.
310   ZSTD_decompressContinue() needs previous data blocks during decompression, up to (1 << windowlog).
311   They should preferably be located contiguously, prior to current block. Alternatively, a round buffer is also possible.
312 
313   @result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst'.
314   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
315 
316   A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
317   Context can then be reset to start a new decompression.
318 */
319 
320 
321 
322 
323 #endif  /* ZSTD_STATIC_H */
324 
325 
326 /*
327     zstd_internal - common functions to include
328     Header File for include
329 */
330 #ifndef ZSTD_CCOMMON_H_MODULE
331 #define ZSTD_CCOMMON_H_MODULE
332 
333 /* *************************************
334 *  Common macros
335 ***************************************/
336 #define MIN(a,b) ((a)<(b) ? (a) : (b))
337 #define MAX(a,b) ((a)>(b) ? (a) : (b))
338 
339 
340 /* *************************************
341 *  Common constants
342 ***************************************/
343 #define ZSTD_MAGICNUMBER 0xFD2FB524   /* v0.4 */
344 
345 #define KB *(1 <<10)
346 #define MB *(1 <<20)
347 #define GB *(1U<<30)
348 
349 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
350 
351 static const size_t ZSTD_blockHeaderSize = 3;
352 static const size_t ZSTD_frameHeaderSize_min = 5;
353 #define ZSTD_frameHeaderSize_max 5         /* define, for static allocation */
354 
355 #define BIT7 128
356 #define BIT6  64
357 #define BIT5  32
358 #define BIT4  16
359 #define BIT1   2
360 #define BIT0   1
361 
362 #define IS_RAW BIT0
363 #define IS_RLE BIT1
364 
365 #define MINMATCH 4
366 #define REPCODE_STARTVALUE 4
367 
368 #define MLbits   7
369 #define LLbits   6
370 #define Offbits  5
371 #define MaxML  ((1<<MLbits) - 1)
372 #define MaxLL  ((1<<LLbits) - 1)
373 #define MaxOff ((1<<Offbits)- 1)
374 #define MLFSELog   10
375 #define LLFSELog   10
376 #define OffFSELog   9
377 #define MaxSeq MAX(MaxLL, MaxML)
378 
379 #define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
380 #define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
381 
382 #define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
383 
384 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
385 
386 
387 /* ******************************************
388 *  Shared functions to include for inlining
389 ********************************************/
ZSTD_copy8(void * dst,const void * src)390 static void ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
391 
392 #define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }
393 
394 /*! ZSTD_wildcopy : custom version of memcpy(), can copy up to 7-8 bytes too many */
ZSTD_wildcopy(void * dst,const void * src,ptrdiff_t length)395 static void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length)
396 {
397     const BYTE* ip = (const BYTE*)src;
398     BYTE* op = (BYTE*)dst;
399     BYTE* const oend = op + length;
400     do
401         COPY8(op, ip)
402     while (op < oend);
403 }
404 
405 
406 
407 /* ******************************************************************
408    FSE : Finite State Entropy coder
409    header file
410 ****************************************************************** */
411 #ifndef FSE_H
412 #define FSE_H
413 
414 #if defined (__cplusplus)
415 extern "C" {
416 #endif
417 
418 
419 /* *****************************************
420 *  Includes
421 ******************************************/
422 #include <stddef.h>    /* size_t, ptrdiff_t */
423 
424 
425 /* *****************************************
426 *  FSE simple functions
427 ******************************************/
428 static size_t FSE_decompress(void* dst,  size_t maxDstSize,
429                 const void* cSrc, size_t cSrcSize);
430 /*!
431 FSE_decompress():
432     Decompress FSE data from buffer 'cSrc', of size 'cSrcSize',
433     into already allocated destination buffer 'dst', of size 'maxDstSize'.
434     return : size of regenerated data (<= maxDstSize)
435              or an error code, which can be tested using FSE_isError()
436 
437     ** Important ** : FSE_decompress() doesn't decompress non-compressible nor RLE data !!!
438     Why ? : making this distinction requires a header.
439     Header management is intentionally delegated to the user layer, which can better manage special cases.
440 */
441 
442 
443 /* *****************************************
444 *  Tool functions
445 ******************************************/
446 /* Error Management */
447 static unsigned    FSE_isError(size_t code);        /* tells if a return value is an error code */
448 
449 
450 
451 /* *****************************************
452 *  FSE detailed API
453 ******************************************/
454 /*!
455 FSE_compress() does the following:
456 1. count symbol occurrence from source[] into table count[]
457 2. normalize counters so that sum(count[]) == Power_of_2 (2^tableLog)
458 3. save normalized counters to memory buffer using writeNCount()
459 4. build encoding table 'CTable' from normalized counters
460 5. encode the data stream using encoding table 'CTable'
461 
462 FSE_decompress() does the following:
463 1. read normalized counters with readNCount()
464 2. build decoding table 'DTable' from normalized counters
465 3. decode the data stream using decoding table 'DTable'
466 
467 The following API allows targeting specific sub-functions for advanced tasks.
468 For example, it's possible to compress several blocks using the same 'CTable',
469 or to save and provide normalized distribution using external method.
470 */
471 
472 
473 /* *** DECOMPRESSION *** */
474 
475 /*!
476 FSE_readNCount():
477    Read compactly saved 'normalizedCounter' from 'rBuffer'.
478    return : size read from 'rBuffer'
479             or an errorCode, which can be tested using FSE_isError()
480             maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
481 static  size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSymbolValuePtr, unsigned* tableLogPtr, const void* rBuffer, size_t rBuffSize);
482 
483 /*!
484 Constructor and Destructor of type FSE_DTable
485     Note that its size depends on 'tableLog' */
486 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
487 
488 /*!
489 FSE_buildDTable():
490    Builds 'dt', which must be already allocated, using FSE_createDTable()
491    return : 0,
492             or an errorCode, which can be tested using FSE_isError() */
493 static size_t FSE_buildDTable ( FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
494 
495 /*!
496 FSE_decompress_usingDTable():
497    Decompress compressed source 'cSrc' of size 'cSrcSize' using 'dt'
498    into 'dst' which must be already allocated.
499    return : size of regenerated data (necessarily <= maxDstSize)
500             or an errorCode, which can be tested using FSE_isError() */
501 static  size_t FSE_decompress_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const FSE_DTable* dt);
502 
503 /*!
504 Tutorial :
505 ----------
506 (Note : these functions only decompress FSE-compressed blocks.
507  If block is uncompressed, use memcpy() instead
508  If block is a single repeated byte, use memset() instead )
509 
510 The first step is to obtain the normalized frequencies of symbols.
511 This can be performed by FSE_readNCount() if it was saved using FSE_writeNCount().
512 'normalizedCounter' must be already allocated, and have at least 'maxSymbolValuePtr[0]+1' cells of signed short.
513 In practice, that means it's necessary to know 'maxSymbolValue' beforehand,
514 or size the table to handle worst case situations (typically 256).
515 FSE_readNCount() will provide 'tableLog' and 'maxSymbolValue'.
516 The result of FSE_readNCount() is the number of bytes read from 'rBuffer'.
517 Note that 'rBufferSize' must be at least 4 bytes, even if useful information is less than that.
518 If there is an error, the function will return an error code, which can be tested using FSE_isError().
519 
520 The next step is to build the decompression tables 'FSE_DTable' from 'normalizedCounter'.
521 This is performed by the function FSE_buildDTable().
522 The space required by 'FSE_DTable' must be already allocated using FSE_createDTable().
523 If there is an error, the function will return an error code, which can be tested using FSE_isError().
524 
525 'FSE_DTable' can then be used to decompress 'cSrc', with FSE_decompress_usingDTable().
526 'cSrcSize' must be strictly correct, otherwise decompression will fail.
527 FSE_decompress_usingDTable() result will tell how many bytes were regenerated (<=maxDstSize).
528 If there is an error, the function will return an error code, which can be tested using FSE_isError(). (ex: dst buffer too small)
529 */
530 
531 
532 #if defined (__cplusplus)
533 }
534 #endif
535 
536 #endif  /* FSE_H */
537 
538 
539 /* ******************************************************************
540    bitstream
541    Part of NewGen Entropy library
542    header file (to include)
543    Copyright (C) 2013-2015, Yann Collet.
544 
545    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
546 
547    Redistribution and use in source and binary forms, with or without
548    modification, are permitted provided that the following conditions are
549    met:
550 
551        * Redistributions of source code must retain the above copyright
552    notice, this list of conditions and the following disclaimer.
553        * Redistributions in binary form must reproduce the above
554    copyright notice, this list of conditions and the following disclaimer
555    in the documentation and/or other materials provided with the
556    distribution.
557 
558    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
559    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
560    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
561    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
562    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
563    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
564    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
565    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
566    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
567    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
568    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
569 
570    You can contact the author at :
571    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
572    - Public forum : https://groups.google.com/forum/#!forum/lz4c
573 ****************************************************************** */
574 #ifndef BITSTREAM_H_MODULE
575 #define BITSTREAM_H_MODULE
576 
577 #if defined (__cplusplus)
578 extern "C" {
579 #endif
580 
581 
582 /*
583 *  This API consists of small unitary functions, which highly benefit from being inlined.
584 *  Since link-time-optimization is not available for all compilers,
585 *  these functions are defined into a .h to be included.
586 */
587 
588 /**********************************************
589 *  bitStream decompression API (read backward)
590 **********************************************/
591 typedef struct
592 {
593     size_t   bitContainer;
594     unsigned bitsConsumed;
595     const char* ptr;
596     const char* start;
597 } BIT_DStream_t;
598 
599 typedef enum { BIT_DStream_unfinished = 0,
600                BIT_DStream_endOfBuffer = 1,
601                BIT_DStream_completed = 2,
602                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
603                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
604 
605 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
606 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
607 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
608 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
609 
610 
611 
612 
613 /******************************************
614 *  unsafe API
615 ******************************************/
616 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
617 /* faster, but works only if nbBits >= 1 */
618 
619 
620 
621 /****************************************************************
622 *  Helper functions
623 ****************************************************************/
BIT_highbit32(U32 val)624 MEM_STATIC unsigned BIT_highbit32 (U32 val)
625 {
626 #   if defined(_MSC_VER)   /* Visual */
627     unsigned long r;
628     return _BitScanReverse(&r, val) ? (unsigned)r : 0;
629 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
630     return __builtin_clz (val) ^ 31;
631 #   else   /* Software version */
632     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 };
633     U32 v = val;
634     unsigned r;
635     v |= v >> 1;
636     v |= v >> 2;
637     v |= v >> 4;
638     v |= v >> 8;
639     v |= v >> 16;
640     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
641     return r;
642 #   endif
643 }
644 
645 
646 /**********************************************************
647 * bitStream decoding
648 **********************************************************/
649 
650 /*!BIT_initDStream
651 *  Initialize a BIT_DStream_t.
652 *  @bitD : a pointer to an already allocated BIT_DStream_t structure
653 *  @srcBuffer must point at the beginning of a bitStream
654 *  @srcSize must be the exact size of the bitStream
655 *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
656 */
BIT_initDStream(BIT_DStream_t * bitD,const void * srcBuffer,size_t srcSize)657 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
658 {
659     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
660 
661     if (srcSize >=  sizeof(size_t))   /* normal case */
662     {
663         U32 contain32;
664         bitD->start = (const char*)srcBuffer;
665         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
666         bitD->bitContainer = MEM_readLEST(bitD->ptr);
667         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
668         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
669         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
670     }
671     else
672     {
673         U32 contain32;
674         bitD->start = (const char*)srcBuffer;
675         bitD->ptr   = bitD->start;
676         bitD->bitContainer = *(const BYTE*)(bitD->start);
677         switch(srcSize)
678         {
679             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);/* fall-through */
680             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);/* fall-through */
681             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);/* fall-through */
682             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24; /* fall-through */
683             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16; /* fall-through */
684             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8; /* fall-through */
685             default: break;
686         }
687         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
688         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
689         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
690         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
691     }
692 
693     return srcSize;
694 }
695 
BIT_lookBits(BIT_DStream_t * bitD,U32 nbBits)696 MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
697 {
698     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
699     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
700 }
701 
702 /*! BIT_lookBitsFast :
703 *   unsafe version; only works only if nbBits >= 1 */
BIT_lookBitsFast(BIT_DStream_t * bitD,U32 nbBits)704 MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
705 {
706     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
707     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
708 }
709 
BIT_skipBits(BIT_DStream_t * bitD,U32 nbBits)710 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
711 {
712     bitD->bitsConsumed += nbBits;
713 }
714 
BIT_readBits(BIT_DStream_t * bitD,U32 nbBits)715 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
716 {
717     size_t value = BIT_lookBits(bitD, nbBits);
718     BIT_skipBits(bitD, nbBits);
719     return value;
720 }
721 
722 /*!BIT_readBitsFast :
723 *  unsafe version; only works only if nbBits >= 1 */
BIT_readBitsFast(BIT_DStream_t * bitD,U32 nbBits)724 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
725 {
726     size_t value = BIT_lookBitsFast(bitD, nbBits);
727     BIT_skipBits(bitD, nbBits);
728     return value;
729 }
730 
BIT_reloadDStream(BIT_DStream_t * bitD)731 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
732 {
733     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
734         return BIT_DStream_overflow;
735 
736     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
737     {
738         bitD->ptr -= bitD->bitsConsumed >> 3;
739         bitD->bitsConsumed &= 7;
740         bitD->bitContainer = MEM_readLEST(bitD->ptr);
741         return BIT_DStream_unfinished;
742     }
743     if (bitD->ptr == bitD->start)
744     {
745         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
746         return BIT_DStream_completed;
747     }
748     {
749         U32 nbBytes = bitD->bitsConsumed >> 3;
750         BIT_DStream_status result = BIT_DStream_unfinished;
751         if (bitD->ptr - nbBytes < bitD->start)
752         {
753             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
754             result = BIT_DStream_endOfBuffer;
755         }
756         bitD->ptr -= nbBytes;
757         bitD->bitsConsumed -= nbBytes*8;
758         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
759         return result;
760     }
761 }
762 
763 /*! BIT_endOfDStream
764 *   @return Tells if DStream has reached its exact end
765 */
BIT_endOfDStream(const BIT_DStream_t * DStream)766 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
767 {
768     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
769 }
770 
771 #if defined (__cplusplus)
772 }
773 #endif
774 
775 #endif /* BITSTREAM_H_MODULE */
776 
777 
778 
779 /* ******************************************************************
780    FSE : Finite State Entropy coder
781    header file for static linking (only)
782    Copyright (C) 2013-2015, Yann Collet
783 
784    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
785 
786    Redistribution and use in source and binary forms, with or without
787    modification, are permitted provided that the following conditions are
788    met:
789 
790        * Redistributions of source code must retain the above copyright
791    notice, this list of conditions and the following disclaimer.
792        * Redistributions in binary form must reproduce the above
793    copyright notice, this list of conditions and the following disclaimer
794    in the documentation and/or other materials provided with the
795    distribution.
796 
797    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
798    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
799    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
800    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
801    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
802    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
803    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
804    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
805    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
806    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
807    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
808 
809    You can contact the author at :
810    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
811    - Public forum : https://groups.google.com/forum/#!forum/lz4c
812 ****************************************************************** */
813 #ifndef FSE_STATIC_H
814 #define FSE_STATIC_H
815 
816 #if defined (__cplusplus)
817 extern "C" {
818 #endif
819 
820 
821 /* *****************************************
822 *  Static allocation
823 *******************************************/
824 /* FSE buffer bounds */
825 #define FSE_NCOUNTBOUND 512
826 #define FSE_BLOCKBOUND(size) (size + (size>>7))
827 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
828 
829 /* It is possible to statically allocate FSE CTable/DTable as a table of unsigned using below macros */
830 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
831 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<maxTableLog))
832 
833 
834 /* *****************************************
835 *  FSE advanced API
836 *******************************************/
837 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
838 /* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
839 
840 static size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
841 /* build a fake FSE_DTable, designed to always generate the same symbolValue */
842 
843 
844 
845 /* *****************************************
846 *  FSE symbol decompression API
847 *******************************************/
848 typedef struct
849 {
850     size_t      state;
851     const void* table;   /* precise table may vary, depending on U16 */
852 } FSE_DState_t;
853 
854 
855 static void     FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
856 
857 static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
858 
859 static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
860 
861 
862 /* *****************************************
863 *  FSE unsafe API
864 *******************************************/
865 static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
866 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
867 
868 
869 /* *****************************************
870 *  Implementation of inlined functions
871 *******************************************/
872 /* decompression */
873 
874 typedef struct {
875     U16 tableLog;
876     U16 fastMode;
877 } FSE_DTableHeader;   /* sizeof U32 */
878 
879 typedef struct
880 {
881     unsigned short newState;
882     unsigned char  symbol;
883     unsigned char  nbBits;
884 } FSE_decode_t;   /* size == U32 */
885 
FSE_initDState(FSE_DState_t * DStatePtr,BIT_DStream_t * bitD,const FSE_DTable * dt)886 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
887 {
888     FSE_DTableHeader DTableH;
889     memcpy(&DTableH, dt, sizeof(DTableH));
890     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
891     BIT_reloadDStream(bitD);
892     DStatePtr->table = dt + 1;
893 }
894 
FSE_decodeSymbol(FSE_DState_t * DStatePtr,BIT_DStream_t * bitD)895 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
896 {
897     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
898     const U32  nbBits = DInfo.nbBits;
899     BYTE symbol = DInfo.symbol;
900     size_t lowBits = BIT_readBits(bitD, nbBits);
901 
902     DStatePtr->state = DInfo.newState + lowBits;
903     return symbol;
904 }
905 
FSE_decodeSymbolFast(FSE_DState_t * DStatePtr,BIT_DStream_t * bitD)906 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
907 {
908     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
909     const U32 nbBits = DInfo.nbBits;
910     BYTE symbol = DInfo.symbol;
911     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
912 
913     DStatePtr->state = DInfo.newState + lowBits;
914     return symbol;
915 }
916 
FSE_endOfDState(const FSE_DState_t * DStatePtr)917 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
918 {
919     return DStatePtr->state == 0;
920 }
921 
922 
923 #if defined (__cplusplus)
924 }
925 #endif
926 
927 #endif  /* FSE_STATIC_H */
928 
929 /* ******************************************************************
930    FSE : Finite State Entropy coder
931    Copyright (C) 2013-2015, Yann Collet.
932 
933    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
934 
935    Redistribution and use in source and binary forms, with or without
936    modification, are permitted provided that the following conditions are
937    met:
938 
939        * Redistributions of source code must retain the above copyright
940    notice, this list of conditions and the following disclaimer.
941        * Redistributions in binary form must reproduce the above
942    copyright notice, this list of conditions and the following disclaimer
943    in the documentation and/or other materials provided with the
944    distribution.
945 
946    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
947    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
948    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
949    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
950    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
951    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
952    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
953    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
954    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
955    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
956    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
957 
958     You can contact the author at :
959     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
960     - Public forum : https://groups.google.com/forum/#!forum/lz4c
961 ****************************************************************** */
962 
963 #ifndef FSE_COMMONDEFS_ONLY
964 
965 /* **************************************************************
966 *  Tuning parameters
967 ****************************************************************/
968 /*!MEMORY_USAGE :
969 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
970 *  Increasing memory usage improves compression ratio
971 *  Reduced memory usage can improve speed, due to cache effect
972 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
973 #define FSE_MAX_MEMORY_USAGE 14
974 #define FSE_DEFAULT_MEMORY_USAGE 13
975 
976 /*!FSE_MAX_SYMBOL_VALUE :
977 *  Maximum symbol value authorized.
978 *  Required for proper stack allocation */
979 #define FSE_MAX_SYMBOL_VALUE 255
980 
981 
982 /* **************************************************************
983 *  template functions type & suffix
984 ****************************************************************/
985 #define FSE_FUNCTION_TYPE BYTE
986 #define FSE_FUNCTION_EXTENSION
987 #define FSE_DECODE_TYPE FSE_decode_t
988 
989 
990 #endif   /* !FSE_COMMONDEFS_ONLY */
991 
992 /* **************************************************************
993 *  Compiler specifics
994 ****************************************************************/
995 #ifdef _MSC_VER    /* Visual Studio */
996 #  define FORCE_INLINE static __forceinline
997 #  include <intrin.h>                    /* For Visual 2005 */
998 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
999 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
1000 #else
1001 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
1002 #    ifdef __GNUC__
1003 #      define FORCE_INLINE static inline __attribute__((always_inline))
1004 #    else
1005 #      define FORCE_INLINE static inline
1006 #    endif
1007 #  else
1008 #    define FORCE_INLINE static
1009 #  endif /* __STDC_VERSION__ */
1010 #endif
1011 
1012 
1013 /* **************************************************************
1014 *  Dependencies
1015 ****************************************************************/
1016 #include <stdlib.h>     /* malloc, free, qsort */
1017 #include <string.h>     /* memcpy, memset */
1018 #include <stdio.h>      /* printf (debug) */
1019 
1020 
1021 /* ***************************************************************
1022 *  Constants
1023 *****************************************************************/
1024 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
1025 #define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
1026 #define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
1027 #define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
1028 #define FSE_MIN_TABLELOG 5
1029 
1030 #define FSE_TABLELOG_ABSOLUTE_MAX 15
1031 #if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
1032 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
1033 #endif
1034 
1035 
1036 /* **************************************************************
1037 *  Error Management
1038 ****************************************************************/
1039 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1040 
1041 
1042 /* **************************************************************
1043 *  Complex types
1044 ****************************************************************/
1045 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
1046 
1047 
1048 /*-**************************************************************
1049 *  Templates
1050 ****************************************************************/
1051 /*
1052   designed to be included
1053   for type-specific functions (template emulation in C)
1054   Objective is to write these functions only once, for improved maintenance
1055 */
1056 
1057 /* safety checks */
1058 #ifndef FSE_FUNCTION_EXTENSION
1059 #  error "FSE_FUNCTION_EXTENSION must be defined"
1060 #endif
1061 #ifndef FSE_FUNCTION_TYPE
1062 #  error "FSE_FUNCTION_TYPE must be defined"
1063 #endif
1064 
1065 /* Function names */
1066 #define FSE_CAT(X,Y) X##Y
1067 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
1068 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
1069 
FSE_tableStep(U32 tableSize)1070 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
1071 
1072 
FSE_buildDTable(FSE_DTable * dt,const short * normalizedCounter,unsigned maxSymbolValue,unsigned tableLog)1073 static size_t FSE_buildDTable(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
1074 {
1075     FSE_DTableHeader DTableH;
1076     void* const tdPtr = dt+1;   /* because dt is unsigned, 32-bits aligned on 32-bits */
1077     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*) (tdPtr);
1078     const U32 tableSize = 1 << tableLog;
1079     const U32 tableMask = tableSize-1;
1080     const U32 step = FSE_tableStep(tableSize);
1081     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
1082     U32 position = 0;
1083     U32 highThreshold = tableSize-1;
1084     const S16 largeLimit= (S16)(1 << (tableLog-1));
1085     U32 noLarge = 1;
1086     U32 s;
1087 
1088     /* Sanity Checks */
1089     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
1090     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
1091 
1092     /* Init, lay down lowprob symbols */
1093     memset(tableDecode, 0, sizeof(FSE_DECODE_TYPE) * (maxSymbolValue+1) );   /* useless init, but keep static analyzer happy, and we don't need to performance optimize legacy decoders */
1094     DTableH.tableLog = (U16)tableLog;
1095     for (s=0; s<=maxSymbolValue; s++)
1096     {
1097         if (normalizedCounter[s]==-1)
1098         {
1099             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
1100             symbolNext[s] = 1;
1101         }
1102         else
1103         {
1104             if (normalizedCounter[s] >= largeLimit) noLarge=0;
1105             symbolNext[s] = normalizedCounter[s];
1106         }
1107     }
1108 
1109     /* Spread symbols */
1110     for (s=0; s<=maxSymbolValue; s++)
1111     {
1112         int i;
1113         for (i=0; i<normalizedCounter[s]; i++)
1114         {
1115             tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
1116             position = (position + step) & tableMask;
1117             while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
1118         }
1119     }
1120 
1121     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
1122 
1123     /* Build Decoding table */
1124     {
1125         U32 i;
1126         for (i=0; i<tableSize; i++)
1127         {
1128             FSE_FUNCTION_TYPE symbol = (FSE_FUNCTION_TYPE)(tableDecode[i].symbol);
1129             U16 nextState = symbolNext[symbol]++;
1130             tableDecode[i].nbBits = (BYTE) (tableLog - BIT_highbit32 ((U32)nextState) );
1131             tableDecode[i].newState = (U16) ( (nextState << tableDecode[i].nbBits) - tableSize);
1132         }
1133     }
1134 
1135     DTableH.fastMode = (U16)noLarge;
1136     memcpy(dt, &DTableH, sizeof(DTableH));
1137     return 0;
1138 }
1139 
1140 
1141 #ifndef FSE_COMMONDEFS_ONLY
1142 /******************************************
1143 *  FSE helper functions
1144 ******************************************/
FSE_isError(size_t code)1145 static unsigned FSE_isError(size_t code) { return ERR_isError(code); }
1146 
1147 
1148 /****************************************************************
1149 *  FSE NCount encoding-decoding
1150 ****************************************************************/
FSE_abs(short a)1151 static short FSE_abs(short a)
1152 {
1153     return a<0 ? -a : a;
1154 }
1155 
FSE_readNCount(short * normalizedCounter,unsigned * maxSVPtr,unsigned * tableLogPtr,const void * headerBuffer,size_t hbSize)1156 static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
1157                  const void* headerBuffer, size_t hbSize)
1158 {
1159     const BYTE* const istart = (const BYTE*) headerBuffer;
1160     const BYTE* const iend = istart + hbSize;
1161     const BYTE* ip = istart;
1162     int nbBits;
1163     int remaining;
1164     int threshold;
1165     U32 bitStream;
1166     int bitCount;
1167     unsigned charnum = 0;
1168     int previous0 = 0;
1169 
1170     if (hbSize < 4) return ERROR(srcSize_wrong);
1171     bitStream = MEM_readLE32(ip);
1172     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
1173     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
1174     bitStream >>= 4;
1175     bitCount = 4;
1176     *tableLogPtr = nbBits;
1177     remaining = (1<<nbBits)+1;
1178     threshold = 1<<nbBits;
1179     nbBits++;
1180 
1181     while ((remaining>1) && (charnum<=*maxSVPtr))
1182     {
1183         if (previous0)
1184         {
1185             unsigned n0 = charnum;
1186             while ((bitStream & 0xFFFF) == 0xFFFF)
1187             {
1188                 n0+=24;
1189                 if (ip < iend-5)
1190                 {
1191                     ip+=2;
1192                     bitStream = MEM_readLE32(ip) >> bitCount;
1193                 }
1194                 else
1195                 {
1196                     bitStream >>= 16;
1197                     bitCount+=16;
1198                 }
1199             }
1200             while ((bitStream & 3) == 3)
1201             {
1202                 n0+=3;
1203                 bitStream>>=2;
1204                 bitCount+=2;
1205             }
1206             n0 += bitStream & 3;
1207             bitCount += 2;
1208             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
1209             while (charnum < n0) normalizedCounter[charnum++] = 0;
1210             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1211             {
1212                 ip += bitCount>>3;
1213                 bitCount &= 7;
1214                 bitStream = MEM_readLE32(ip) >> bitCount;
1215             }
1216             else
1217                 bitStream >>= 2;
1218         }
1219         {
1220             const short max = (short)((2*threshold-1)-remaining);
1221             short count;
1222 
1223             if ((bitStream & (threshold-1)) < (U32)max)
1224             {
1225                 count = (short)(bitStream & (threshold-1));
1226                 bitCount   += nbBits-1;
1227             }
1228             else
1229             {
1230                 count = (short)(bitStream & (2*threshold-1));
1231                 if (count >= threshold) count -= max;
1232                 bitCount   += nbBits;
1233             }
1234 
1235             count--;   /* extra accuracy */
1236             remaining -= FSE_abs(count);
1237             normalizedCounter[charnum++] = count;
1238             previous0 = !count;
1239             while (remaining < threshold)
1240             {
1241                 nbBits--;
1242                 threshold >>= 1;
1243             }
1244 
1245             {
1246                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
1247                 {
1248                     ip += bitCount>>3;
1249                     bitCount &= 7;
1250                 }
1251                 else
1252                 {
1253                     bitCount -= (int)(8 * (iend - 4 - ip));
1254                     ip = iend - 4;
1255                 }
1256                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
1257             }
1258         }
1259     }
1260     if (remaining != 1) return ERROR(GENERIC);
1261     *maxSVPtr = charnum-1;
1262 
1263     ip += (bitCount+7)>>3;
1264     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
1265     return ip-istart;
1266 }
1267 
1268 
1269 /*********************************************************
1270 *  Decompression (Byte symbols)
1271 *********************************************************/
FSE_buildDTable_rle(FSE_DTable * dt,BYTE symbolValue)1272 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
1273 {
1274     void* ptr = dt;
1275     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1276     void* dPtr = dt + 1;
1277     FSE_decode_t* const cell = (FSE_decode_t*)dPtr;
1278 
1279     DTableH->tableLog = 0;
1280     DTableH->fastMode = 0;
1281 
1282     cell->newState = 0;
1283     cell->symbol = symbolValue;
1284     cell->nbBits = 0;
1285 
1286     return 0;
1287 }
1288 
1289 
FSE_buildDTable_raw(FSE_DTable * dt,unsigned nbBits)1290 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
1291 {
1292     void* ptr = dt;
1293     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
1294     void* dPtr = dt + 1;
1295     FSE_decode_t* const dinfo = (FSE_decode_t*)dPtr;
1296     const unsigned tableSize = 1 << nbBits;
1297     const unsigned tableMask = tableSize - 1;
1298     const unsigned maxSymbolValue = tableMask;
1299     unsigned s;
1300 
1301     /* Sanity checks */
1302     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
1303 
1304     /* Build Decoding Table */
1305     DTableH->tableLog = (U16)nbBits;
1306     DTableH->fastMode = 1;
1307     for (s=0; s<=maxSymbolValue; s++)
1308     {
1309         dinfo[s].newState = 0;
1310         dinfo[s].symbol = (BYTE)s;
1311         dinfo[s].nbBits = (BYTE)nbBits;
1312     }
1313 
1314     return 0;
1315 }
1316 
FSE_decompress_usingDTable_generic(void * dst,size_t maxDstSize,const void * cSrc,size_t cSrcSize,const FSE_DTable * dt,const unsigned fast)1317 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
1318           void* dst, size_t maxDstSize,
1319     const void* cSrc, size_t cSrcSize,
1320     const FSE_DTable* dt, const unsigned fast)
1321 {
1322     BYTE* const ostart = (BYTE*) dst;
1323     BYTE* op = ostart;
1324     BYTE* const omax = op + maxDstSize;
1325     BYTE* const olimit = omax-3;
1326 
1327     BIT_DStream_t bitD;
1328     FSE_DState_t state1;
1329     FSE_DState_t state2;
1330     size_t errorCode;
1331 
1332     /* Init */
1333     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
1334     if (FSE_isError(errorCode)) return errorCode;
1335 
1336     FSE_initDState(&state1, &bitD, dt);
1337     FSE_initDState(&state2, &bitD, dt);
1338 
1339 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
1340 
1341     /* 4 symbols per loop */
1342     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op<olimit) ; op+=4)
1343     {
1344         op[0] = FSE_GETSYMBOL(&state1);
1345 
1346         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1347             BIT_reloadDStream(&bitD);
1348 
1349         op[1] = FSE_GETSYMBOL(&state2);
1350 
1351         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1352             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
1353 
1354         op[2] = FSE_GETSYMBOL(&state1);
1355 
1356         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
1357             BIT_reloadDStream(&bitD);
1358 
1359         op[3] = FSE_GETSYMBOL(&state2);
1360     }
1361 
1362     /* tail */
1363     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
1364     while (1)
1365     {
1366         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
1367             break;
1368 
1369         *op++ = FSE_GETSYMBOL(&state1);
1370 
1371         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
1372             break;
1373 
1374         *op++ = FSE_GETSYMBOL(&state2);
1375     }
1376 
1377     /* end ? */
1378     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
1379         return op-ostart;
1380 
1381     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
1382 
1383     return ERROR(corruption_detected);
1384 }
1385 
1386 
FSE_decompress_usingDTable(void * dst,size_t originalSize,const void * cSrc,size_t cSrcSize,const FSE_DTable * dt)1387 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
1388                             const void* cSrc, size_t cSrcSize,
1389                             const FSE_DTable* dt)
1390 {
1391     FSE_DTableHeader DTableH;
1392     U32 fastMode;
1393 
1394     memcpy(&DTableH, dt, sizeof(DTableH));
1395     fastMode = DTableH.fastMode;
1396 
1397     /* select fast mode (static) */
1398     if (fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
1399     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
1400 }
1401 
1402 
FSE_decompress(void * dst,size_t maxDstSize,const void * cSrc,size_t cSrcSize)1403 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
1404 {
1405     const BYTE* const istart = (const BYTE*)cSrc;
1406     const BYTE* ip = istart;
1407     short counting[FSE_MAX_SYMBOL_VALUE+1];
1408     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
1409     unsigned tableLog;
1410     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
1411     size_t errorCode;
1412 
1413     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
1414 
1415     /* normal FSE decoding mode */
1416     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
1417     if (FSE_isError(errorCode)) return errorCode;
1418     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
1419     ip += errorCode;
1420     cSrcSize -= errorCode;
1421 
1422     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
1423     if (FSE_isError(errorCode)) return errorCode;
1424 
1425     /* always return, even if it is an error code */
1426     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
1427 }
1428 
1429 
1430 
1431 #endif   /* FSE_COMMONDEFS_ONLY */
1432 
1433 
1434 /* ******************************************************************
1435    Huff0 : Huffman coder, part of New Generation Entropy library
1436    header file
1437    Copyright (C) 2013-2015, Yann Collet.
1438 
1439    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1440 
1441    Redistribution and use in source and binary forms, with or without
1442    modification, are permitted provided that the following conditions are
1443    met:
1444 
1445        * Redistributions of source code must retain the above copyright
1446    notice, this list of conditions and the following disclaimer.
1447        * Redistributions in binary form must reproduce the above
1448    copyright notice, this list of conditions and the following disclaimer
1449    in the documentation and/or other materials provided with the
1450    distribution.
1451 
1452    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1453    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1454    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1455    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1456    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1457    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1458    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1459    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1460    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1461    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1462    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1463 
1464    You can contact the author at :
1465    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
1466    - Public forum : https://groups.google.com/forum/#!forum/lz4c
1467 ****************************************************************** */
1468 #ifndef HUFF0_H
1469 #define HUFF0_H
1470 
1471 #if defined (__cplusplus)
1472 extern "C" {
1473 #endif
1474 
1475 
1476 /* ****************************************
1477 *  Dependency
1478 ******************************************/
1479 #include <stddef.h>    /* size_t */
1480 
1481 
1482 /* ****************************************
1483 *  Huff0 simple functions
1484 ******************************************/
1485 static size_t HUF_decompress(void* dst,  size_t dstSize,
1486                 const void* cSrc, size_t cSrcSize);
1487 /*!
1488 HUF_decompress():
1489     Decompress Huff0 data from buffer 'cSrc', of size 'cSrcSize',
1490     into already allocated destination buffer 'dst', of size 'dstSize'.
1491     'dstSize' must be the exact size of original (uncompressed) data.
1492     Note : in contrast with FSE, HUF_decompress can regenerate RLE (cSrcSize==1) and uncompressed (cSrcSize==dstSize) data, because it knows size to regenerate.
1493     @return : size of regenerated data (== dstSize)
1494               or an error code, which can be tested using HUF_isError()
1495 */
1496 
1497 
1498 /* ****************************************
1499 *  Tool functions
1500 ******************************************/
1501 /* Error Management */
1502 static unsigned    HUF_isError(size_t code);        /* tells if a return value is an error code */
1503 
1504 
1505 #if defined (__cplusplus)
1506 }
1507 #endif
1508 
1509 #endif   /* HUFF0_H */
1510 
1511 
1512 /* ******************************************************************
1513    Huff0 : Huffman coder, part of New Generation Entropy library
1514    header file for static linking (only)
1515    Copyright (C) 2013-2015, Yann Collet
1516 
1517    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1518 
1519    Redistribution and use in source and binary forms, with or without
1520    modification, are permitted provided that the following conditions are
1521    met:
1522 
1523        * Redistributions of source code must retain the above copyright
1524    notice, this list of conditions and the following disclaimer.
1525        * Redistributions in binary form must reproduce the above
1526    copyright notice, this list of conditions and the following disclaimer
1527    in the documentation and/or other materials provided with the
1528    distribution.
1529 
1530    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1531    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1532    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1533    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1534    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1535    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1536    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1537    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1538    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1539    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1540    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1541 
1542    You can contact the author at :
1543    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
1544    - Public forum : https://groups.google.com/forum/#!forum/lz4c
1545 ****************************************************************** */
1546 #ifndef HUFF0_STATIC_H
1547 #define HUFF0_STATIC_H
1548 
1549 #if defined (__cplusplus)
1550 extern "C" {
1551 #endif
1552 
1553 
1554 
1555 /* ****************************************
1556 *  Static allocation macros
1557 ******************************************/
1558 /* static allocation of Huff0's DTable */
1559 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<maxTableLog))  /* nb Cells; use unsigned short for X2, unsigned int for X4 */
1560 #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
1561         unsigned short DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
1562 #define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
1563         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
1564 #define HUF_CREATE_STATIC_DTABLEX6(DTable, maxTableLog) \
1565         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog) * 3 / 2] = { maxTableLog }
1566 
1567 
1568 /* ****************************************
1569 *  Advanced decompression functions
1570 ******************************************/
1571 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
1572 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbols decoder */
1573 
1574 
1575 /* ****************************************
1576 *  Huff0 detailed API
1577 ******************************************/
1578 /*!
1579 HUF_decompress() does the following:
1580 1. select the decompression algorithm (X2, X4, X6) based on pre-computed heuristics
1581 2. build Huffman table from save, using HUF_readDTableXn()
1582 3. decode 1 or 4 segments in parallel using HUF_decompressSXn_usingDTable
1583 
1584 */
1585 static size_t HUF_readDTableX2 (unsigned short* DTable, const void* src, size_t srcSize);
1586 static size_t HUF_readDTableX4 (unsigned* DTable, const void* src, size_t srcSize);
1587 
1588 static size_t HUF_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned short* DTable);
1589 static size_t HUF_decompress4X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned* DTable);
1590 
1591 
1592 #if defined (__cplusplus)
1593 }
1594 #endif
1595 
1596 #endif /* HUFF0_STATIC_H */
1597 
1598 
1599 
1600 /* ******************************************************************
1601    Huff0 : Huffman coder, part of New Generation Entropy library
1602    Copyright (C) 2013-2015, Yann Collet.
1603 
1604    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1605 
1606    Redistribution and use in source and binary forms, with or without
1607    modification, are permitted provided that the following conditions are
1608    met:
1609 
1610        * Redistributions of source code must retain the above copyright
1611    notice, this list of conditions and the following disclaimer.
1612        * Redistributions in binary form must reproduce the above
1613    copyright notice, this list of conditions and the following disclaimer
1614    in the documentation and/or other materials provided with the
1615    distribution.
1616 
1617    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1618    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1619    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1620    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1621    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1622    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1623    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1624    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1625    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1626    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1627    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1628 
1629     You can contact the author at :
1630     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
1631 ****************************************************************** */
1632 
1633 /* **************************************************************
1634 *  Compiler specifics
1635 ****************************************************************/
1636 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
1637 /* inline is defined */
1638 #elif defined(_MSC_VER)
1639 #  define inline __inline
1640 #else
1641 #  define inline /* disable inline */
1642 #endif
1643 
1644 
1645 #ifdef _MSC_VER    /* Visual Studio */
1646 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
1647 #endif
1648 
1649 
1650 /* **************************************************************
1651 *  Includes
1652 ****************************************************************/
1653 #include <stdlib.h>     /* malloc, free, qsort */
1654 #include <string.h>     /* memcpy, memset */
1655 #include <stdio.h>      /* printf (debug) */
1656 
1657 
1658 /* **************************************************************
1659 *  Constants
1660 ****************************************************************/
1661 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
1662 #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
1663 #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
1664 #define HUF_MAX_SYMBOL_VALUE 255
1665 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
1666 #  error "HUF_MAX_TABLELOG is too large !"
1667 #endif
1668 
1669 
1670 /* **************************************************************
1671 *  Error Management
1672 ****************************************************************/
HUF_isError(size_t code)1673 static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
1674 #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
1675 
1676 
1677 
1678 /*-*******************************************************
1679 *  Huff0 : Huffman block decompression
1680 *********************************************************/
1681 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
1682 
1683 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
1684 
1685 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
1686 
1687 /*! HUF_readStats
1688     Read compact Huffman tree, saved by HUF_writeCTable
1689     @huffWeight : destination buffer
1690     @return : size read from `src`
1691 */
HUF_readStats(BYTE * huffWeight,size_t hwSize,U32 * rankStats,U32 * nbSymbolsPtr,U32 * tableLogPtr,const void * src,size_t srcSize)1692 static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
1693                             U32* nbSymbolsPtr, U32* tableLogPtr,
1694                             const void* src, size_t srcSize)
1695 {
1696     U32 weightTotal;
1697     U32 tableLog;
1698     const BYTE* ip = (const BYTE*) src;
1699     size_t iSize;
1700     size_t oSize;
1701     U32 n;
1702 
1703     if (!srcSize) return ERROR(srcSize_wrong);
1704     iSize = ip[0];
1705     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
1706 
1707     if (iSize >= 128)  /* special header */
1708     {
1709         if (iSize >= (242))   /* RLE */
1710         {
1711             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
1712             oSize = l[iSize-242];
1713             memset(huffWeight, 1, hwSize);
1714             iSize = 0;
1715         }
1716         else   /* Incompressible */
1717         {
1718             oSize = iSize - 127;
1719             iSize = ((oSize+1)/2);
1720             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1721             if (oSize >= hwSize) return ERROR(corruption_detected);
1722             ip += 1;
1723             for (n=0; n<oSize; n+=2)
1724             {
1725                 huffWeight[n]   = ip[n/2] >> 4;
1726                 huffWeight[n+1] = ip[n/2] & 15;
1727             }
1728         }
1729     }
1730     else  /* header compressed with FSE (normal case) */
1731     {
1732         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
1733         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
1734         if (FSE_isError(oSize)) return oSize;
1735     }
1736 
1737     /* collect weight stats */
1738     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
1739     weightTotal = 0;
1740     for (n=0; n<oSize; n++)
1741     {
1742         if (huffWeight[n] >= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1743         rankStats[huffWeight[n]]++;
1744         weightTotal += (1 << huffWeight[n]) >> 1;
1745     }
1746     if (weightTotal == 0) return ERROR(corruption_detected);
1747 
1748     /* get last non-null symbol weight (implied, total must be 2^n) */
1749     tableLog = BIT_highbit32(weightTotal) + 1;
1750     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
1751     {
1752         U32 total = 1 << tableLog;
1753         U32 rest = total - weightTotal;
1754         U32 verif = 1 << BIT_highbit32(rest);
1755         U32 lastWeight = BIT_highbit32(rest) + 1;
1756         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
1757         huffWeight[oSize] = (BYTE)lastWeight;
1758         rankStats[lastWeight]++;
1759     }
1760 
1761     /* check tree construction validity */
1762     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
1763 
1764     /* results */
1765     *nbSymbolsPtr = (U32)(oSize+1);
1766     *tableLogPtr = tableLog;
1767     return iSize+1;
1768 }
1769 
1770 
1771 /**************************/
1772 /* single-symbol decoding */
1773 /**************************/
1774 
HUF_readDTableX2(U16 * DTable,const void * src,size_t srcSize)1775 static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
1776 {
1777     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
1778     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
1779     U32 tableLog = 0;
1780     size_t iSize;
1781     U32 nbSymbols = 0;
1782     U32 n;
1783     U32 nextRankStart;
1784     void* const dtPtr = DTable + 1;
1785     HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
1786 
1787     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
1788     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
1789 
1790     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
1791     if (HUF_isError(iSize)) return iSize;
1792 
1793     /* check result */
1794     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
1795     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
1796 
1797     /* Prepare ranks */
1798     nextRankStart = 0;
1799     for (n=1; n<=tableLog; n++)
1800     {
1801         U32 current = nextRankStart;
1802         nextRankStart += (rankVal[n] << (n-1));
1803         rankVal[n] = current;
1804     }
1805 
1806     /* fill DTable */
1807     for (n=0; n<nbSymbols; n++)
1808     {
1809         const U32 w = huffWeight[n];
1810         const U32 length = (1 << w) >> 1;
1811         U32 i;
1812         HUF_DEltX2 D;
1813         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
1814         for (i = rankVal[w]; i < rankVal[w] + length; i++)
1815             dt[i] = D;
1816         rankVal[w] += length;
1817     }
1818 
1819     return iSize;
1820 }
1821 
HUF_decodeSymbolX2(BIT_DStream_t * Dstream,const HUF_DEltX2 * dt,const U32 dtLog)1822 static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
1823 {
1824         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
1825         const BYTE c = dt[val].byte;
1826         BIT_skipBits(Dstream, dt[val].nbBits);
1827         return c;
1828 }
1829 
1830 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
1831     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
1832 
1833 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
1834     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
1835         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1836 
1837 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
1838     if (MEM_64bits()) \
1839         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
1840 
HUF_decodeStreamX2(BYTE * p,BIT_DStream_t * const bitDPtr,BYTE * const pEnd,const HUF_DEltX2 * const dt,const U32 dtLog)1841 static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
1842 {
1843     BYTE* const pStart = p;
1844 
1845     /* up to 4 symbols at a time */
1846     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
1847     {
1848         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1849         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
1850         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
1851         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1852     }
1853 
1854     /* closer to the end */
1855     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
1856         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1857 
1858     /* no more data to retrieve from bitstream, hence no need to reload */
1859     while (p < pEnd)
1860         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
1861 
1862     return pEnd-pStart;
1863 }
1864 
1865 
HUF_decompress4X2_usingDTable(void * dst,size_t dstSize,const void * cSrc,size_t cSrcSize,const U16 * DTable)1866 static size_t HUF_decompress4X2_usingDTable(
1867           void* dst,  size_t dstSize,
1868     const void* cSrc, size_t cSrcSize,
1869     const U16* DTable)
1870 {
1871     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
1872 
1873     {
1874         const BYTE* const istart = (const BYTE*) cSrc;
1875         BYTE* const ostart = (BYTE*) dst;
1876         BYTE* const oend = ostart + dstSize;
1877         const void* const dtPtr = DTable;
1878         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)dtPtr) +1;
1879         const U32 dtLog = DTable[0];
1880         size_t errorCode;
1881 
1882         /* Init */
1883         BIT_DStream_t bitD1;
1884         BIT_DStream_t bitD2;
1885         BIT_DStream_t bitD3;
1886         BIT_DStream_t bitD4;
1887         const size_t length1 = MEM_readLE16(istart);
1888         const size_t length2 = MEM_readLE16(istart+2);
1889         const size_t length3 = MEM_readLE16(istart+4);
1890         size_t length4;
1891         const BYTE* const istart1 = istart + 6;  /* jumpTable */
1892         const BYTE* const istart2 = istart1 + length1;
1893         const BYTE* const istart3 = istart2 + length2;
1894         const BYTE* const istart4 = istart3 + length3;
1895         const size_t segmentSize = (dstSize+3) / 4;
1896         BYTE* const opStart2 = ostart + segmentSize;
1897         BYTE* const opStart3 = opStart2 + segmentSize;
1898         BYTE* const opStart4 = opStart3 + segmentSize;
1899         BYTE* op1 = ostart;
1900         BYTE* op2 = opStart2;
1901         BYTE* op3 = opStart3;
1902         BYTE* op4 = opStart4;
1903         U32 endSignal;
1904 
1905         length4 = cSrcSize - (length1 + length2 + length3 + 6);
1906         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
1907         errorCode = BIT_initDStream(&bitD1, istart1, length1);
1908         if (HUF_isError(errorCode)) return errorCode;
1909         errorCode = BIT_initDStream(&bitD2, istart2, length2);
1910         if (HUF_isError(errorCode)) return errorCode;
1911         errorCode = BIT_initDStream(&bitD3, istart3, length3);
1912         if (HUF_isError(errorCode)) return errorCode;
1913         errorCode = BIT_initDStream(&bitD4, istart4, length4);
1914         if (HUF_isError(errorCode)) return errorCode;
1915 
1916         /* 16-32 symbols per loop (4-8 symbols per stream) */
1917         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1918         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
1919         {
1920             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1921             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1922             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1923             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1924             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
1925             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
1926             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
1927             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
1928             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
1929             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
1930             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
1931             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
1932             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
1933             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
1934             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
1935             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
1936 
1937             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
1938         }
1939 
1940         /* check corruption */
1941         if (op1 > opStart2) return ERROR(corruption_detected);
1942         if (op2 > opStart3) return ERROR(corruption_detected);
1943         if (op3 > opStart4) return ERROR(corruption_detected);
1944         /* note : op4 supposed already verified within main loop */
1945 
1946         /* finish bitStreams one by one */
1947         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
1948         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
1949         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
1950         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
1951 
1952         /* check */
1953         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
1954         if (!endSignal) return ERROR(corruption_detected);
1955 
1956         /* decoded size */
1957         return dstSize;
1958     }
1959 }
1960 
1961 
HUF_decompress4X2(void * dst,size_t dstSize,const void * cSrc,size_t cSrcSize)1962 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
1963 {
1964     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
1965     const BYTE* ip = (const BYTE*) cSrc;
1966     size_t errorCode;
1967 
1968     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
1969     if (HUF_isError(errorCode)) return errorCode;
1970     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
1971     ip += errorCode;
1972     cSrcSize -= errorCode;
1973 
1974     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
1975 }
1976 
1977 
1978 /***************************/
1979 /* double-symbols decoding */
1980 /***************************/
1981 
HUF_fillDTableX4Level2(HUF_DEltX4 * DTable,U32 sizeLog,const U32 consumed,const U32 * rankValOrigin,const int minWeight,const sortedSymbol_t * sortedSymbols,const U32 sortedListSize,U32 nbBitsBaseline,U16 baseSeq)1982 static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
1983                            const U32* rankValOrigin, const int minWeight,
1984                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
1985                            U32 nbBitsBaseline, U16 baseSeq)
1986 {
1987     HUF_DEltX4 DElt;
1988     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
1989     U32 s;
1990 
1991     /* get pre-calculated rankVal */
1992     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
1993 
1994     /* fill skipped values */
1995     if (minWeight>1)
1996     {
1997         U32 i, skipSize = rankVal[minWeight];
1998         MEM_writeLE16(&(DElt.sequence), baseSeq);
1999         DElt.nbBits   = (BYTE)(consumed);
2000         DElt.length   = 1;
2001         for (i = 0; i < skipSize; i++)
2002             DTable[i] = DElt;
2003     }
2004 
2005     /* fill DTable */
2006     for (s=0; s<sortedListSize; s++)   /* note : sortedSymbols already skipped */
2007     {
2008         const U32 symbol = sortedSymbols[s].symbol;
2009         const U32 weight = sortedSymbols[s].weight;
2010         const U32 nbBits = nbBitsBaseline - weight;
2011         const U32 length = 1 << (sizeLog-nbBits);
2012         const U32 start = rankVal[weight];
2013         U32 i = start;
2014         const U32 end = start + length;
2015 
2016         MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
2017         DElt.nbBits = (BYTE)(nbBits + consumed);
2018         DElt.length = 2;
2019         do { DTable[i++] = DElt; } while (i<end);   /* since length >= 1 */
2020 
2021         rankVal[weight] += length;
2022     }
2023 }
2024 
2025 typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
2026 
HUF_fillDTableX4(HUF_DEltX4 * DTable,const U32 targetLog,const sortedSymbol_t * sortedList,const U32 sortedListSize,const U32 * rankStart,rankVal_t rankValOrigin,const U32 maxWeight,const U32 nbBitsBaseline)2027 static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
2028                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
2029                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
2030                            const U32 nbBitsBaseline)
2031 {
2032     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
2033     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
2034     const U32 minBits  = nbBitsBaseline - maxWeight;
2035     U32 s;
2036 
2037     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
2038 
2039     /* fill DTable */
2040     for (s=0; s<sortedListSize; s++)
2041     {
2042         const U16 symbol = sortedList[s].symbol;
2043         const U32 weight = sortedList[s].weight;
2044         const U32 nbBits = nbBitsBaseline - weight;
2045         const U32 start = rankVal[weight];
2046         const U32 length = 1 << (targetLog-nbBits);
2047 
2048         if (targetLog-nbBits >= minBits)   /* enough room for a second symbol */
2049         {
2050             U32 sortedRank;
2051             int minWeight = nbBits + scaleLog;
2052             if (minWeight < 1) minWeight = 1;
2053             sortedRank = rankStart[minWeight];
2054             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
2055                            rankValOrigin[nbBits], minWeight,
2056                            sortedList+sortedRank, sortedListSize-sortedRank,
2057                            nbBitsBaseline, symbol);
2058         }
2059         else
2060         {
2061             U32 i;
2062             const U32 end = start + length;
2063             HUF_DEltX4 DElt;
2064 
2065             MEM_writeLE16(&(DElt.sequence), symbol);
2066             DElt.nbBits   = (BYTE)(nbBits);
2067             DElt.length   = 1;
2068             for (i = start; i < end; i++)
2069                 DTable[i] = DElt;
2070         }
2071         rankVal[weight] += length;
2072     }
2073 }
2074 
HUF_readDTableX4(U32 * DTable,const void * src,size_t srcSize)2075 static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
2076 {
2077     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
2078     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
2079     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
2080     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
2081     U32* const rankStart = rankStart0+1;
2082     rankVal_t rankVal;
2083     U32 tableLog, maxW, sizeOfSort, nbSymbols;
2084     const U32 memLog = DTable[0];
2085     size_t iSize;
2086     void* dtPtr = DTable;
2087     HUF_DEltX4* const dt = ((HUF_DEltX4*)dtPtr) + 1;
2088 
2089     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
2090     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
2091     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
2092 
2093     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
2094     if (HUF_isError(iSize)) return iSize;
2095 
2096     /* check result */
2097     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
2098 
2099     /* find maxWeight */
2100     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
2101         { if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
2102 
2103     /* Get start index of each weight */
2104     {
2105         U32 w, nextRankStart = 0;
2106         for (w=1; w<=maxW; w++)
2107         {
2108             U32 current = nextRankStart;
2109             nextRankStart += rankStats[w];
2110             rankStart[w] = current;
2111         }
2112         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
2113         sizeOfSort = nextRankStart;
2114     }
2115 
2116     /* sort symbols by weight */
2117     {
2118         U32 s;
2119         for (s=0; s<nbSymbols; s++)
2120         {
2121             U32 w = weightList[s];
2122             U32 r = rankStart[w]++;
2123             sortedSymbol[r].symbol = (BYTE)s;
2124             sortedSymbol[r].weight = (BYTE)w;
2125         }
2126         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
2127     }
2128 
2129     /* Build rankVal */
2130     {
2131         const U32 minBits = tableLog+1 - maxW;
2132         U32 nextRankVal = 0;
2133         U32 w, consumed;
2134         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
2135         U32* rankVal0 = rankVal[0];
2136         for (w=1; w<=maxW; w++)
2137         {
2138             U32 current = nextRankVal;
2139             nextRankVal += rankStats[w] << (w+rescale);
2140             rankVal0[w] = current;
2141         }
2142         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
2143         {
2144             U32* rankValPtr = rankVal[consumed];
2145             for (w = 1; w <= maxW; w++)
2146             {
2147                 rankValPtr[w] = rankVal0[w] >> consumed;
2148             }
2149         }
2150     }
2151 
2152     HUF_fillDTableX4(dt, memLog,
2153                    sortedSymbol, sizeOfSort,
2154                    rankStart0, rankVal, maxW,
2155                    tableLog+1);
2156 
2157     return iSize;
2158 }
2159 
2160 
HUF_decodeSymbolX4(void * op,BIT_DStream_t * DStream,const HUF_DEltX4 * dt,const U32 dtLog)2161 static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2162 {
2163     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2164     memcpy(op, dt+val, 2);
2165     BIT_skipBits(DStream, dt[val].nbBits);
2166     return dt[val].length;
2167 }
2168 
HUF_decodeLastSymbolX4(void * op,BIT_DStream_t * DStream,const HUF_DEltX4 * dt,const U32 dtLog)2169 static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
2170 {
2171     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
2172     memcpy(op, dt+val, 1);
2173     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
2174     else
2175     {
2176         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
2177         {
2178             BIT_skipBits(DStream, dt[val].nbBits);
2179             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
2180                 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 */
2181         }
2182     }
2183     return 1;
2184 }
2185 
2186 
2187 #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
2188     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2189 
2190 #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
2191     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
2192         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2193 
2194 #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
2195     if (MEM_64bits()) \
2196         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
2197 
HUF_decodeStreamX4(BYTE * p,BIT_DStream_t * bitDPtr,BYTE * const pEnd,const HUF_DEltX4 * const dt,const U32 dtLog)2198 static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
2199 {
2200     BYTE* const pStart = p;
2201 
2202     /* up to 8 symbols at a time */
2203     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
2204     {
2205         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2206         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
2207         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
2208         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2209     }
2210 
2211     /* closer to the end */
2212     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
2213         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
2214 
2215     while (p <= pEnd-2)
2216         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
2217 
2218     if (p < pEnd)
2219         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
2220 
2221     return p-pStart;
2222 }
2223 
HUF_decompress4X4_usingDTable(void * dst,size_t dstSize,const void * cSrc,size_t cSrcSize,const U32 * DTable)2224 static size_t HUF_decompress4X4_usingDTable(
2225           void* dst,  size_t dstSize,
2226     const void* cSrc, size_t cSrcSize,
2227     const U32* DTable)
2228 {
2229     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
2230 
2231     {
2232         const BYTE* const istart = (const BYTE*) cSrc;
2233         BYTE* const ostart = (BYTE*) dst;
2234         BYTE* const oend = ostart + dstSize;
2235         const void* const dtPtr = DTable;
2236         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)dtPtr) +1;
2237         const U32 dtLog = DTable[0];
2238         size_t errorCode;
2239 
2240         /* Init */
2241         BIT_DStream_t bitD1;
2242         BIT_DStream_t bitD2;
2243         BIT_DStream_t bitD3;
2244         BIT_DStream_t bitD4;
2245         const size_t length1 = MEM_readLE16(istart);
2246         const size_t length2 = MEM_readLE16(istart+2);
2247         const size_t length3 = MEM_readLE16(istart+4);
2248         size_t length4;
2249         const BYTE* const istart1 = istart + 6;  /* jumpTable */
2250         const BYTE* const istart2 = istart1 + length1;
2251         const BYTE* const istart3 = istart2 + length2;
2252         const BYTE* const istart4 = istart3 + length3;
2253         const size_t segmentSize = (dstSize+3) / 4;
2254         BYTE* const opStart2 = ostart + segmentSize;
2255         BYTE* const opStart3 = opStart2 + segmentSize;
2256         BYTE* const opStart4 = opStart3 + segmentSize;
2257         BYTE* op1 = ostart;
2258         BYTE* op2 = opStart2;
2259         BYTE* op3 = opStart3;
2260         BYTE* op4 = opStart4;
2261         U32 endSignal;
2262 
2263         length4 = cSrcSize - (length1 + length2 + length3 + 6);
2264         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
2265         errorCode = BIT_initDStream(&bitD1, istart1, length1);
2266         if (HUF_isError(errorCode)) return errorCode;
2267         errorCode = BIT_initDStream(&bitD2, istart2, length2);
2268         if (HUF_isError(errorCode)) return errorCode;
2269         errorCode = BIT_initDStream(&bitD3, istart3, length3);
2270         if (HUF_isError(errorCode)) return errorCode;
2271         errorCode = BIT_initDStream(&bitD4, istart4, length4);
2272         if (HUF_isError(errorCode)) return errorCode;
2273 
2274         /* 16-32 symbols per loop (4-8 symbols per stream) */
2275         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2276         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
2277         {
2278             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2279             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2280             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2281             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2282             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
2283             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
2284             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
2285             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
2286             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
2287             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
2288             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
2289             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
2290             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
2291             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
2292             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
2293             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
2294 
2295             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
2296         }
2297 
2298         /* check corruption */
2299         if (op1 > opStart2) return ERROR(corruption_detected);
2300         if (op2 > opStart3) return ERROR(corruption_detected);
2301         if (op3 > opStart4) return ERROR(corruption_detected);
2302         /* note : op4 supposed already verified within main loop */
2303 
2304         /* finish bitStreams one by one */
2305         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
2306         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
2307         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
2308         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
2309 
2310         /* check */
2311         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
2312         if (!endSignal) return ERROR(corruption_detected);
2313 
2314         /* decoded size */
2315         return dstSize;
2316     }
2317 }
2318 
2319 
HUF_decompress4X4(void * dst,size_t dstSize,const void * cSrc,size_t cSrcSize)2320 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2321 {
2322     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
2323     const BYTE* ip = (const BYTE*) cSrc;
2324 
2325     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
2326     if (HUF_isError(hSize)) return hSize;
2327     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
2328     ip += hSize;
2329     cSrcSize -= hSize;
2330 
2331     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
2332 }
2333 
2334 
2335 /**********************************/
2336 /* Generic decompression selector */
2337 /**********************************/
2338 
2339 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
2340 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
2341 {
2342     /* single, double, quad */
2343     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
2344     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
2345     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
2346     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
2347     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
2348     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
2349     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
2350     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
2351     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
2352     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
2353     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
2354     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
2355     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
2356     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
2357     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
2358     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
2359 };
2360 
2361 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
2362 
HUF_decompress(void * dst,size_t dstSize,const void * cSrc,size_t cSrcSize)2363 static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
2364 {
2365     static const decompressionAlgo decompress[3] = { HUF_decompress4X2, HUF_decompress4X4, NULL };
2366     /* estimate decompression time */
2367     U32 Q;
2368     const U32 D256 = (U32)(dstSize >> 8);
2369     U32 Dtime[3];
2370     U32 algoNb = 0;
2371     int n;
2372 
2373     /* validation checks */
2374     if (dstSize == 0) return ERROR(dstSize_tooSmall);
2375     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
2376     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
2377     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
2378 
2379     /* decoder timing evaluation */
2380     Q = (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 since dstSize > cSrcSize */
2381     for (n=0; n<3; n++)
2382         Dtime[n] = algoTime[Q][n].tableTime + (algoTime[Q][n].decode256Time * D256);
2383 
2384     Dtime[1] += Dtime[1] >> 4; Dtime[2] += Dtime[2] >> 3; /* advantage to algorithms using less memory, for cache eviction */
2385 
2386     if (Dtime[1] < Dtime[0]) algoNb = 1;
2387 
2388     return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
2389 
2390     //return HUF_decompress4X2(dst, dstSize, cSrc, cSrcSize);   /* multi-streams single-symbol decoding */
2391     //return HUF_decompress4X4(dst, dstSize, cSrc, cSrcSize);   /* multi-streams double-symbols decoding */
2392     //return HUF_decompress4X6(dst, dstSize, cSrc, cSrcSize);   /* multi-streams quad-symbols decoding */
2393 }
2394 
2395 
2396 
2397 #endif   /* ZSTD_CCOMMON_H_MODULE */
2398 
2399 
2400 /*
2401     zstd - decompression module fo v0.4 legacy format
2402     Copyright (C) 2015-2016, Yann Collet.
2403 
2404     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2405 
2406     Redistribution and use in source and binary forms, with or without
2407     modification, are permitted provided that the following conditions are
2408     met:
2409     * Redistributions of source code must retain the above copyright
2410     notice, this list of conditions and the following disclaimer.
2411     * Redistributions in binary form must reproduce the above
2412     copyright notice, this list of conditions and the following disclaimer
2413     in the documentation and/or other materials provided with the
2414     distribution.
2415     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2416     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2417     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2418     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2419     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2420     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2421     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2422     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2423     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2424     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2425     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2426 
2427     You can contact the author at :
2428     - zstd source repository : https://github.com/Cyan4973/zstd
2429     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
2430 */
2431 
2432 /* ***************************************************************
2433 *  Tuning parameters
2434 *****************************************************************/
2435 /*!
2436  * HEAPMODE :
2437  * Select how default decompression function ZSTD_decompress() will allocate memory,
2438  * in memory stack (0), or in memory heap (1, requires malloc())
2439  */
2440 #ifndef ZSTD_HEAPMODE
2441 #  define ZSTD_HEAPMODE 1
2442 #endif
2443 
2444 
2445 /* *******************************************************
2446 *  Includes
2447 *********************************************************/
2448 #include <stdlib.h>      /* calloc */
2449 #include <string.h>      /* memcpy, memmove */
2450 #include <stdio.h>       /* debug : printf */
2451 
2452 
2453 /* *******************************************************
2454 *  Compiler specifics
2455 *********************************************************/
2456 #ifdef _MSC_VER    /* Visual Studio */
2457 #  include <intrin.h>                    /* For Visual 2005 */
2458 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
2459 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
2460 #endif
2461 
2462 
2463 /* *************************************
2464 *  Local types
2465 ***************************************/
2466 typedef struct
2467 {
2468     blockType_t blockType;
2469     U32 origSize;
2470 } blockProperties_t;
2471 
2472 
2473 /* *******************************************************
2474 *  Memory operations
2475 **********************************************************/
ZSTD_copy4(void * dst,const void * src)2476 static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
2477 
2478 
2479 /* *************************************
2480 *  Error Management
2481 ***************************************/
2482 
2483 /*! ZSTD_isError
2484 *   tells if a return value is an error code */
ZSTD_isError(size_t code)2485 static unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
2486 
2487 
2488 /* *************************************************************
2489 *   Context management
2490 ***************************************************************/
2491 typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
2492                ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock } ZSTD_dStage;
2493 
2494 struct ZSTDv04_Dctx_s
2495 {
2496     U32 LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
2497     U32 OffTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
2498     U32 MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
2499     const void* previousDstEnd;
2500     const void* base;
2501     const void* vBase;
2502     const void* dictEnd;
2503     size_t expected;
2504     size_t headerSize;
2505     ZSTD_parameters params;
2506     blockType_t bType;
2507     ZSTD_dStage stage;
2508     const BYTE* litPtr;
2509     size_t litSize;
2510     BYTE litBuffer[BLOCKSIZE + 8 /* margin for wildcopy */];
2511     BYTE headerBuffer[ZSTD_frameHeaderSize_max];
2512 };  /* typedef'd to ZSTD_DCtx within "zstd_static.h" */
2513 
ZSTD_resetDCtx(ZSTD_DCtx * dctx)2514 static size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx)
2515 {
2516     dctx->expected = ZSTD_frameHeaderSize_min;
2517     dctx->stage = ZSTDds_getFrameHeaderSize;
2518     dctx->previousDstEnd = NULL;
2519     dctx->base = NULL;
2520     dctx->vBase = NULL;
2521     dctx->dictEnd = NULL;
2522     return 0;
2523 }
2524 
ZSTD_createDCtx(void)2525 static ZSTD_DCtx* ZSTD_createDCtx(void)
2526 {
2527     ZSTD_DCtx* dctx = (ZSTD_DCtx*)malloc(sizeof(ZSTD_DCtx));
2528     if (dctx==NULL) return NULL;
2529     ZSTD_resetDCtx(dctx);
2530     return dctx;
2531 }
2532 
ZSTD_freeDCtx(ZSTD_DCtx * dctx)2533 static size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
2534 {
2535     free(dctx);
2536     return 0;
2537 }
2538 
2539 
2540 /* *************************************************************
2541 *   Decompression section
2542 ***************************************************************/
2543 /** ZSTD_decodeFrameHeader_Part1
2544 *   decode the 1st part of the Frame Header, which tells Frame Header size.
2545 *   srcSize must be == ZSTD_frameHeaderSize_min
2546 *   @return : the full size of the Frame Header */
ZSTD_decodeFrameHeader_Part1(ZSTD_DCtx * zc,const void * src,size_t srcSize)2547 static size_t ZSTD_decodeFrameHeader_Part1(ZSTD_DCtx* zc, const void* src, size_t srcSize)
2548 {
2549     U32 magicNumber;
2550     if (srcSize != ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong);
2551     magicNumber = MEM_readLE32(src);
2552     if (magicNumber != ZSTD_MAGICNUMBER) return ERROR(prefix_unknown);
2553     zc->headerSize = ZSTD_frameHeaderSize_min;
2554     return zc->headerSize;
2555 }
2556 
2557 
ZSTD_getFrameParams(ZSTD_parameters * params,const void * src,size_t srcSize)2558 static size_t ZSTD_getFrameParams(ZSTD_parameters* params, const void* src, size_t srcSize)
2559 {
2560     U32 magicNumber;
2561     if (srcSize < ZSTD_frameHeaderSize_min) return ZSTD_frameHeaderSize_max;
2562     magicNumber = MEM_readLE32(src);
2563     if (magicNumber != ZSTD_MAGICNUMBER) return ERROR(prefix_unknown);
2564     memset(params, 0, sizeof(*params));
2565     params->windowLog = (((const BYTE*)src)[4] & 15) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
2566     if ((((const BYTE*)src)[4] >> 4) != 0) return ERROR(frameParameter_unsupported);   /* reserved bits */
2567     return 0;
2568 }
2569 
2570 /** ZSTD_decodeFrameHeader_Part2
2571 *   decode the full Frame Header
2572 *   srcSize must be the size provided by ZSTD_decodeFrameHeader_Part1
2573 *   @return : 0, or an error code, which can be tested using ZSTD_isError() */
ZSTD_decodeFrameHeader_Part2(ZSTD_DCtx * zc,const void * src,size_t srcSize)2574 static size_t ZSTD_decodeFrameHeader_Part2(ZSTD_DCtx* zc, const void* src, size_t srcSize)
2575 {
2576     size_t result;
2577     if (srcSize != zc->headerSize) return ERROR(srcSize_wrong);
2578     result = ZSTD_getFrameParams(&(zc->params), src, srcSize);
2579     if ((MEM_32bits()) && (zc->params.windowLog > 25)) return ERROR(frameParameter_unsupported);
2580     return result;
2581 }
2582 
2583 
ZSTD_getcBlockSize(const void * src,size_t srcSize,blockProperties_t * bpPtr)2584 static size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
2585 {
2586     const BYTE* const in = (const BYTE* const)src;
2587     BYTE headerFlags;
2588     U32 cSize;
2589 
2590     if (srcSize < 3) return ERROR(srcSize_wrong);
2591 
2592     headerFlags = *in;
2593     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
2594 
2595     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
2596     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
2597 
2598     if (bpPtr->blockType == bt_end) return 0;
2599     if (bpPtr->blockType == bt_rle) return 1;
2600     return cSize;
2601 }
2602 
ZSTD_copyRawBlock(void * dst,size_t maxDstSize,const void * src,size_t srcSize)2603 static size_t ZSTD_copyRawBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
2604 {
2605     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
2606     if (srcSize > 0) {
2607         memcpy(dst, src, srcSize);
2608     }
2609     return srcSize;
2610 }
2611 
2612 
2613 /** ZSTD_decompressLiterals
2614     @return : nb of bytes read from src, or an error code*/
ZSTD_decompressLiterals(void * dst,size_t * maxDstSizePtr,const void * src,size_t srcSize)2615 static size_t ZSTD_decompressLiterals(void* dst, size_t* maxDstSizePtr,
2616                                 const void* src, size_t srcSize)
2617 {
2618     const BYTE* ip = (const BYTE*)src;
2619 
2620     const size_t litSize = (MEM_readLE32(src) & 0x1FFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2621     const size_t litCSize = (MEM_readLE32(ip+2) & 0xFFFFFF) >> 5;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2622 
2623     if (litSize > *maxDstSizePtr) return ERROR(corruption_detected);
2624     if (litCSize + 5 > srcSize) return ERROR(corruption_detected);
2625 
2626     if (HUF_isError(HUF_decompress(dst, litSize, ip+5, litCSize))) return ERROR(corruption_detected);
2627 
2628     *maxDstSizePtr = litSize;
2629     return litCSize + 5;
2630 }
2631 
2632 
2633 /** ZSTD_decodeLiteralsBlock
2634     @return : nb of bytes read from src (< srcSize ) */
ZSTD_decodeLiteralsBlock(ZSTD_DCtx * dctx,const void * src,size_t srcSize)2635 static size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
2636                           const void* src, size_t srcSize)   /* note : srcSize < BLOCKSIZE */
2637 {
2638     const BYTE* const istart = (const BYTE*) src;
2639 
2640     /* any compressed block with literals segment must be at least this size */
2641     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
2642 
2643     switch(*istart & 3)
2644     {
2645     /* compressed */
2646     case 0:
2647         {
2648             size_t litSize = BLOCKSIZE;
2649             const size_t readSize = ZSTD_decompressLiterals(dctx->litBuffer, &litSize, src, srcSize);
2650             dctx->litPtr = dctx->litBuffer;
2651             dctx->litSize = litSize;
2652             memset(dctx->litBuffer + dctx->litSize, 0, 8);
2653             return readSize;   /* works if it's an error too */
2654         }
2655     case IS_RAW:
2656         {
2657             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2658             if (litSize > srcSize-11)   /* risk of reading too far with wildcopy */
2659             {
2660                 if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2661                 if (litSize > srcSize-3) return ERROR(corruption_detected);
2662                 memcpy(dctx->litBuffer, istart, litSize);
2663                 dctx->litPtr = dctx->litBuffer;
2664                 dctx->litSize = litSize;
2665                 memset(dctx->litBuffer + dctx->litSize, 0, 8);
2666                 return litSize+3;
2667             }
2668             /* direct reference into compressed stream */
2669             dctx->litPtr = istart+3;
2670             dctx->litSize = litSize;
2671             return litSize+3;        }
2672     case IS_RLE:
2673         {
2674             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
2675             if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
2676             memset(dctx->litBuffer, istart[3], litSize + 8);
2677             dctx->litPtr = dctx->litBuffer;
2678             dctx->litSize = litSize;
2679             return 4;
2680         }
2681     default:
2682         return ERROR(corruption_detected);   /* forbidden nominal case */
2683     }
2684 }
2685 
2686 
ZSTD_decodeSeqHeaders(int * nbSeq,const BYTE ** dumpsPtr,size_t * dumpsLengthPtr,FSE_DTable * DTableLL,FSE_DTable * DTableML,FSE_DTable * DTableOffb,const void * src,size_t srcSize)2687 static size_t ZSTD_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
2688                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
2689                          const void* src, size_t srcSize)
2690 {
2691     const BYTE* const istart = (const BYTE* const)src;
2692     const BYTE* ip = istart;
2693     const BYTE* const iend = istart + srcSize;
2694     U32 LLtype, Offtype, MLtype;
2695     U32 LLlog, Offlog, MLlog;
2696     size_t dumpsLength;
2697 
2698     /* check */
2699     if (srcSize < 5) return ERROR(srcSize_wrong);
2700 
2701     /* SeqHead */
2702     *nbSeq = MEM_readLE16(ip); ip+=2;
2703     LLtype  = *ip >> 6;
2704     Offtype = (*ip >> 4) & 3;
2705     MLtype  = (*ip >> 2) & 3;
2706     if (*ip & 2)
2707     {
2708         dumpsLength  = ip[2];
2709         dumpsLength += ip[1] << 8;
2710         ip += 3;
2711     }
2712     else
2713     {
2714         dumpsLength  = ip[1];
2715         dumpsLength += (ip[0] & 1) << 8;
2716         ip += 2;
2717     }
2718     *dumpsPtr = ip;
2719     ip += dumpsLength;
2720     *dumpsLengthPtr = dumpsLength;
2721 
2722     /* check */
2723     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
2724 
2725     /* sequences */
2726     {
2727         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL >= MaxOff */
2728         size_t headerSize;
2729 
2730         /* Build DTables */
2731         switch(LLtype)
2732         {
2733         case bt_rle :
2734             LLlog = 0;
2735             FSE_buildDTable_rle(DTableLL, *ip++); break;
2736         case bt_raw :
2737             LLlog = LLbits;
2738             FSE_buildDTable_raw(DTableLL, LLbits); break;
2739         default :
2740             {   U32 max = MaxLL;
2741                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
2742                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2743                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
2744                 ip += headerSize;
2745                 FSE_buildDTable(DTableLL, norm, max, LLlog);
2746         }   }
2747 
2748         switch(Offtype)
2749         {
2750         case bt_rle :
2751             Offlog = 0;
2752             if (ip > iend-2) return ERROR(srcSize_wrong);   /* min : "raw", hence no header, but at least xxLog bits */
2753             FSE_buildDTable_rle(DTableOffb, *ip++ & MaxOff); /* if *ip > MaxOff, data is corrupted */
2754             break;
2755         case bt_raw :
2756             Offlog = Offbits;
2757             FSE_buildDTable_raw(DTableOffb, Offbits); break;
2758         default :
2759             {   U32 max = MaxOff;
2760                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
2761                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2762                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
2763                 ip += headerSize;
2764                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
2765         }   }
2766 
2767         switch(MLtype)
2768         {
2769         case bt_rle :
2770             MLlog = 0;
2771             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
2772             FSE_buildDTable_rle(DTableML, *ip++); break;
2773         case bt_raw :
2774             MLlog = MLbits;
2775             FSE_buildDTable_raw(DTableML, MLbits); break;
2776         default :
2777             {   U32 max = MaxML;
2778                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
2779                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
2780                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
2781                 ip += headerSize;
2782                 FSE_buildDTable(DTableML, norm, max, MLlog);
2783     }   }   }
2784 
2785     return ip-istart;
2786 }
2787 
2788 
2789 typedef struct {
2790     size_t litLength;
2791     size_t offset;
2792     size_t matchLength;
2793 } seq_t;
2794 
2795 typedef struct {
2796     BIT_DStream_t DStream;
2797     FSE_DState_t stateLL;
2798     FSE_DState_t stateOffb;
2799     FSE_DState_t stateML;
2800     size_t prevOffset;
2801     const BYTE* dumps;
2802     const BYTE* dumpsEnd;
2803 } seqState_t;
2804 
2805 
ZSTD_decodeSequence(seq_t * seq,seqState_t * seqState)2806 static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
2807 {
2808     size_t litLength;
2809     size_t prevOffset;
2810     size_t offset;
2811     size_t matchLength;
2812     const BYTE* dumps = seqState->dumps;
2813     const BYTE* const de = seqState->dumpsEnd;
2814 
2815     /* Literal length */
2816     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
2817     prevOffset = litLength ? seq->offset : seqState->prevOffset;
2818     if (litLength == MaxLL) {
2819         const U32 add = dumps<de ? *dumps++ : 0;
2820         if (add < 255) litLength += add;
2821         else if (dumps + 3 <= de) {
2822             litLength = MEM_readLE24(dumps);
2823             dumps += 3;
2824         }
2825         if (dumps >= de) { dumps = de-1; }  /* late correction, to avoid read overflow (data is now corrupted anyway) */
2826     }
2827 
2828     /* Offset */
2829     {   static const U32 offsetPrefix[MaxOff+1] = {
2830                 1 /*fake*/, 1, 2, 4, 8, 16, 32, 64, 128, 256,
2831                 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144,
2832                 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, /*fake*/ 1, 1, 1, 1, 1 };
2833         U32 offsetCode, nbBits;
2834         offsetCode = FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream));   /* <= maxOff, by table construction */
2835         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
2836         nbBits = offsetCode - 1;
2837         if (offsetCode==0) nbBits = 0;   /* cmove */
2838         offset = offsetPrefix[offsetCode] + BIT_readBits(&(seqState->DStream), nbBits);
2839         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
2840         if (offsetCode==0) offset = prevOffset;   /* cmove */
2841         if (offsetCode | !litLength) seqState->prevOffset = seq->offset;   /* cmove */
2842     }
2843 
2844     /* MatchLength */
2845     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
2846     if (matchLength == MaxML) {
2847         const U32 add = dumps<de ? *dumps++ : 0;
2848         if (add < 255) matchLength += add;
2849         else if (dumps + 3 <= de){
2850             matchLength = MEM_readLE24(dumps);
2851             dumps += 3;
2852         }
2853         if (dumps >= de) { dumps = de-1; }  /* late correction, to avoid read overflow (data is now corrupted anyway) */
2854     }
2855     matchLength += MINMATCH;
2856 
2857     /* save result */
2858     seq->litLength = litLength;
2859     seq->offset = offset;
2860     seq->matchLength = matchLength;
2861     seqState->dumps = dumps;
2862 }
2863 
2864 
ZSTD_execSequence(BYTE * op,BYTE * const oend,seq_t sequence,const BYTE ** litPtr,const BYTE * const litLimit,const BYTE * const base,const BYTE * const vBase,const BYTE * const dictEnd)2865 static size_t ZSTD_execSequence(BYTE* op,
2866                                 BYTE* const oend, seq_t sequence,
2867                                 const BYTE** litPtr, const BYTE* const litLimit,
2868                                 const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
2869 {
2870     static const int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
2871     static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
2872     BYTE* const oLitEnd = op + sequence.litLength;
2873     const size_t sequenceLength = sequence.litLength + sequence.matchLength;
2874     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
2875     BYTE* const oend_8 = oend-8;
2876     const BYTE* const litEnd = *litPtr + sequence.litLength;
2877     const BYTE* match = oLitEnd - sequence.offset;
2878 
2879     /* check */
2880     if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall);   /* last match must start at a minimum distance of 8 from oend */
2881     if (oMatchEnd > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
2882     if (litEnd > litLimit) return ERROR(corruption_detected);   /* risk read beyond lit buffer */
2883 
2884     /* copy Literals */
2885     ZSTD_wildcopy(op, *litPtr, sequence.litLength);   /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
2886     op = oLitEnd;
2887     *litPtr = litEnd;   /* update for next sequence */
2888 
2889     /* copy Match */
2890     if (sequence.offset > (size_t)(oLitEnd - base))
2891     {
2892         /* offset beyond prefix */
2893         if (sequence.offset > (size_t)(oLitEnd - vBase))
2894             return ERROR(corruption_detected);
2895         match = dictEnd - (base-match);
2896         if (match + sequence.matchLength <= dictEnd)
2897         {
2898             memmove(oLitEnd, match, sequence.matchLength);
2899             return sequenceLength;
2900         }
2901         /* span extDict & currentPrefixSegment */
2902         {
2903             size_t length1 = dictEnd - match;
2904             memmove(oLitEnd, match, length1);
2905             op = oLitEnd + length1;
2906             sequence.matchLength -= length1;
2907             match = base;
2908             if (op > oend_8 || sequence.matchLength < MINMATCH) {
2909               while (op < oMatchEnd) *op++ = *match++;
2910               return sequenceLength;
2911             }
2912         }
2913     }
2914     /* Requirement: op <= oend_8 */
2915 
2916     /* match within prefix */
2917     if (sequence.offset < 8) {
2918         /* close range match, overlap */
2919         const int sub2 = dec64table[sequence.offset];
2920         op[0] = match[0];
2921         op[1] = match[1];
2922         op[2] = match[2];
2923         op[3] = match[3];
2924         match += dec32table[sequence.offset];
2925         ZSTD_copy4(op+4, match);
2926         match -= sub2;
2927     } else {
2928         ZSTD_copy8(op, match);
2929     }
2930     op += 8; match += 8;
2931 
2932     if (oMatchEnd > oend-(16-MINMATCH))
2933     {
2934         if (op < oend_8)
2935         {
2936             ZSTD_wildcopy(op, match, oend_8 - op);
2937             match += oend_8 - op;
2938             op = oend_8;
2939         }
2940         while (op < oMatchEnd) *op++ = *match++;
2941     }
2942     else
2943     {
2944         ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8, but must be signed */
2945     }
2946     return sequenceLength;
2947 }
2948 
2949 
ZSTD_decompressSequences(ZSTD_DCtx * dctx,void * dst,size_t maxDstSize,const void * seqStart,size_t seqSize)2950 static size_t ZSTD_decompressSequences(
2951                                ZSTD_DCtx* dctx,
2952                                void* dst, size_t maxDstSize,
2953                          const void* seqStart, size_t seqSize)
2954 {
2955     const BYTE* ip = (const BYTE*)seqStart;
2956     const BYTE* const iend = ip + seqSize;
2957     BYTE* const ostart = (BYTE* const)dst;
2958     BYTE* op = ostart;
2959     BYTE* const oend = ostart + maxDstSize;
2960     size_t errorCode, dumpsLength;
2961     const BYTE* litPtr = dctx->litPtr;
2962     const BYTE* const litEnd = litPtr + dctx->litSize;
2963     int nbSeq;
2964     const BYTE* dumps;
2965     U32* DTableLL = dctx->LLTable;
2966     U32* DTableML = dctx->MLTable;
2967     U32* DTableOffb = dctx->OffTable;
2968     const BYTE* const base = (const BYTE*) (dctx->base);
2969     const BYTE* const vBase = (const BYTE*) (dctx->vBase);
2970     const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
2971 
2972     /* Build Decoding Tables */
2973     errorCode = ZSTD_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
2974                                       DTableLL, DTableML, DTableOffb,
2975                                       ip, iend-ip);
2976     if (ZSTD_isError(errorCode)) return errorCode;
2977     ip += errorCode;
2978 
2979     /* Regen sequences */
2980     {
2981         seq_t sequence;
2982         seqState_t seqState;
2983 
2984         memset(&sequence, 0, sizeof(sequence));
2985         sequence.offset = 4;
2986         seqState.dumps = dumps;
2987         seqState.dumpsEnd = dumps + dumpsLength;
2988         seqState.prevOffset = 4;
2989         errorCode = BIT_initDStream(&(seqState.DStream), ip, iend-ip);
2990         if (ERR_isError(errorCode)) return ERROR(corruption_detected);
2991         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
2992         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
2993         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
2994 
2995         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; )
2996         {
2997             size_t oneSeqSize;
2998             nbSeq--;
2999             ZSTD_decodeSequence(&sequence, &seqState);
3000             oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
3001             if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
3002             op += oneSeqSize;
3003         }
3004 
3005         /* check if reached exact end */
3006         if ( !BIT_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* DStream should be entirely and exactly consumed; otherwise data is corrupted */
3007 
3008         /* last literal segment */
3009         {
3010             size_t lastLLSize = litEnd - litPtr;
3011             if (litPtr > litEnd) return ERROR(corruption_detected);
3012             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
3013             if (lastLLSize > 0) {
3014                 if (op != litPtr) memcpy(op, litPtr, lastLLSize);
3015                 op += lastLLSize;
3016             }
3017         }
3018     }
3019 
3020     return op-ostart;
3021 }
3022 
3023 
ZSTD_checkContinuity(ZSTD_DCtx * dctx,const void * dst)3024 static void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst)
3025 {
3026     if (dst != dctx->previousDstEnd)   /* not contiguous */
3027     {
3028         dctx->dictEnd = dctx->previousDstEnd;
3029         dctx->vBase = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
3030         dctx->base = dst;
3031         dctx->previousDstEnd = dst;
3032     }
3033 }
3034 
3035 
ZSTD_decompressBlock_internal(ZSTD_DCtx * dctx,void * dst,size_t maxDstSize,const void * src,size_t srcSize)3036 static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
3037                             void* dst, size_t maxDstSize,
3038                       const void* src, size_t srcSize)
3039 {
3040     /* blockType == blockCompressed */
3041     const BYTE* ip = (const BYTE*)src;
3042     size_t litCSize;
3043 
3044     if (srcSize > BLOCKSIZE) return ERROR(corruption_detected);
3045 
3046     /* Decode literals sub-block */
3047     litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
3048     if (ZSTD_isError(litCSize)) return litCSize;
3049     ip += litCSize;
3050     srcSize -= litCSize;
3051 
3052     return ZSTD_decompressSequences(dctx, dst, maxDstSize, ip, srcSize);
3053 }
3054 
3055 
ZSTD_decompress_usingDict(ZSTD_DCtx * ctx,void * dst,size_t maxDstSize,const void * src,size_t srcSize,const void * dict,size_t dictSize)3056 static size_t ZSTD_decompress_usingDict(ZSTD_DCtx* ctx,
3057                                  void* dst, size_t maxDstSize,
3058                                  const void* src, size_t srcSize,
3059                                  const void* dict, size_t dictSize)
3060 {
3061     const BYTE* ip = (const BYTE*)src;
3062     const BYTE* iend = ip + srcSize;
3063     BYTE* const ostart = (BYTE* const)dst;
3064     BYTE* op = ostart;
3065     BYTE* const oend = ostart + maxDstSize;
3066     size_t remainingSize = srcSize;
3067     blockProperties_t blockProperties;
3068 
3069     /* init */
3070     ZSTD_resetDCtx(ctx);
3071     if (dict)
3072     {
3073         ZSTD_decompress_insertDictionary(ctx, dict, dictSize);
3074         ctx->dictEnd = ctx->previousDstEnd;
3075         ctx->vBase = (const char*)dst - ((const char*)(ctx->previousDstEnd) - (const char*)(ctx->base));
3076         ctx->base = dst;
3077     }
3078     else
3079     {
3080         ctx->vBase = ctx->base = ctx->dictEnd = dst;
3081     }
3082 
3083     /* Frame Header */
3084     {
3085         size_t frameHeaderSize;
3086         if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
3087         frameHeaderSize = ZSTD_decodeFrameHeader_Part1(ctx, src, ZSTD_frameHeaderSize_min);
3088         if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
3089         if (srcSize < frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
3090         ip += frameHeaderSize; remainingSize -= frameHeaderSize;
3091         frameHeaderSize = ZSTD_decodeFrameHeader_Part2(ctx, src, frameHeaderSize);
3092         if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
3093     }
3094 
3095     /* Loop on each block */
3096     while (1)
3097     {
3098         size_t decodedSize=0;
3099         size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &blockProperties);
3100         if (ZSTD_isError(cBlockSize)) return cBlockSize;
3101 
3102         ip += ZSTD_blockHeaderSize;
3103         remainingSize -= ZSTD_blockHeaderSize;
3104         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
3105 
3106         switch(blockProperties.blockType)
3107         {
3108         case bt_compressed:
3109             decodedSize = ZSTD_decompressBlock_internal(ctx, op, oend-op, ip, cBlockSize);
3110             break;
3111         case bt_raw :
3112             decodedSize = ZSTD_copyRawBlock(op, oend-op, ip, cBlockSize);
3113             break;
3114         case bt_rle :
3115             return ERROR(GENERIC);   /* not yet supported */
3116             break;
3117         case bt_end :
3118             /* end of frame */
3119             if (remainingSize) return ERROR(srcSize_wrong);
3120             break;
3121         default:
3122             return ERROR(GENERIC);   /* impossible */
3123         }
3124         if (cBlockSize == 0) break;   /* bt_end */
3125 
3126         if (ZSTD_isError(decodedSize)) return decodedSize;
3127         op += decodedSize;
3128         ip += cBlockSize;
3129         remainingSize -= cBlockSize;
3130     }
3131 
3132     return op-ostart;
3133 }
3134 
3135 /* ZSTD_errorFrameSizeInfoLegacy() :
3136    assumes `cSize` and `dBound` are _not_ NULL */
ZSTD_errorFrameSizeInfoLegacy(size_t * cSize,unsigned long long * dBound,size_t ret)3137 static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
3138 {
3139     *cSize = ret;
3140     *dBound = ZSTD_CONTENTSIZE_ERROR;
3141 }
3142 
ZSTDv04_findFrameSizeInfoLegacy(const void * src,size_t srcSize,size_t * cSize,unsigned long long * dBound)3143 void ZSTDv04_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
3144 {
3145     const BYTE* ip = (const BYTE*)src;
3146     size_t remainingSize = srcSize;
3147     size_t nbBlocks = 0;
3148     blockProperties_t blockProperties;
3149 
3150     /* Frame Header */
3151     if (srcSize < ZSTD_frameHeaderSize_min) {
3152         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3153         return;
3154     }
3155     if (MEM_readLE32(src) != ZSTD_MAGICNUMBER) {
3156         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
3157         return;
3158     }
3159     ip += ZSTD_frameHeaderSize_min; remainingSize -= ZSTD_frameHeaderSize_min;
3160 
3161     /* Loop on each block */
3162     while (1)
3163     {
3164         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
3165         if (ZSTD_isError(cBlockSize)) {
3166             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
3167             return;
3168         }
3169 
3170         ip += ZSTD_blockHeaderSize;
3171         remainingSize -= ZSTD_blockHeaderSize;
3172         if (cBlockSize > remainingSize) {
3173             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
3174             return;
3175         }
3176 
3177         if (cBlockSize == 0) break;   /* bt_end */
3178 
3179         ip += cBlockSize;
3180         remainingSize -= cBlockSize;
3181         nbBlocks++;
3182     }
3183 
3184     *cSize = ip - (const BYTE*)src;
3185     *dBound = nbBlocks * BLOCKSIZE;
3186 }
3187 
3188 /* ******************************
3189 *  Streaming Decompression API
3190 ********************************/
ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx * dctx)3191 static size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx)
3192 {
3193     return dctx->expected;
3194 }
3195 
ZSTD_decompressContinue(ZSTD_DCtx * ctx,void * dst,size_t maxDstSize,const void * src,size_t srcSize)3196 static size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3197 {
3198     /* Sanity check */
3199     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
3200     ZSTD_checkContinuity(ctx, dst);
3201 
3202     /* Decompress : frame header; part 1 */
3203     switch (ctx->stage)
3204     {
3205     case ZSTDds_getFrameHeaderSize :
3206         /* get frame header size */
3207         if (srcSize != ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong);   /* impossible */
3208         ctx->headerSize = ZSTD_decodeFrameHeader_Part1(ctx, src, ZSTD_frameHeaderSize_min);
3209         if (ZSTD_isError(ctx->headerSize)) return ctx->headerSize;
3210         memcpy(ctx->headerBuffer, src, ZSTD_frameHeaderSize_min);
3211         if (ctx->headerSize > ZSTD_frameHeaderSize_min) return ERROR(GENERIC);   /* impossible */
3212         ctx->expected = 0;   /* not necessary to copy more */
3213         /* fallthrough */
3214     case ZSTDds_decodeFrameHeader:
3215         /* get frame header */
3216         {   size_t const result = ZSTD_decodeFrameHeader_Part2(ctx, ctx->headerBuffer, ctx->headerSize);
3217             if (ZSTD_isError(result)) return result;
3218             ctx->expected = ZSTD_blockHeaderSize;
3219             ctx->stage = ZSTDds_decodeBlockHeader;
3220             return 0;
3221         }
3222     case ZSTDds_decodeBlockHeader:
3223         /* Decode block header */
3224         {   blockProperties_t bp;
3225             size_t const blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
3226             if (ZSTD_isError(blockSize)) return blockSize;
3227             if (bp.blockType == bt_end)
3228             {
3229                 ctx->expected = 0;
3230                 ctx->stage = ZSTDds_getFrameHeaderSize;
3231             }
3232             else
3233             {
3234                 ctx->expected = blockSize;
3235                 ctx->bType = bp.blockType;
3236                 ctx->stage = ZSTDds_decompressBlock;
3237             }
3238             return 0;
3239         }
3240     case ZSTDds_decompressBlock:
3241         {
3242             /* Decompress : block content */
3243             size_t rSize;
3244             switch(ctx->bType)
3245             {
3246             case bt_compressed:
3247                 rSize = ZSTD_decompressBlock_internal(ctx, dst, maxDstSize, src, srcSize);
3248                 break;
3249             case bt_raw :
3250                 rSize = ZSTD_copyRawBlock(dst, maxDstSize, src, srcSize);
3251                 break;
3252             case bt_rle :
3253                 return ERROR(GENERIC);   /* not yet handled */
3254                 break;
3255             case bt_end :   /* should never happen (filtered at phase 1) */
3256                 rSize = 0;
3257                 break;
3258             default:
3259                 return ERROR(GENERIC);
3260             }
3261             ctx->stage = ZSTDds_decodeBlockHeader;
3262             ctx->expected = ZSTD_blockHeaderSize;
3263             ctx->previousDstEnd = (char*)dst + rSize;
3264             return rSize;
3265         }
3266     default:
3267         return ERROR(GENERIC);   /* impossible */
3268     }
3269 }
3270 
3271 
ZSTD_decompress_insertDictionary(ZSTD_DCtx * ctx,const void * dict,size_t dictSize)3272 static void ZSTD_decompress_insertDictionary(ZSTD_DCtx* ctx, const void* dict, size_t dictSize)
3273 {
3274     ctx->dictEnd = ctx->previousDstEnd;
3275     ctx->vBase = (const char*)dict - ((const char*)(ctx->previousDstEnd) - (const char*)(ctx->base));
3276     ctx->base = dict;
3277     ctx->previousDstEnd = (const char*)dict + dictSize;
3278 }
3279 
3280 
3281 
3282 /*
3283     Buffered version of Zstd compression library
3284     Copyright (C) 2015, Yann Collet.
3285 
3286     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
3287 
3288     Redistribution and use in source and binary forms, with or without
3289     modification, are permitted provided that the following conditions are
3290     met:
3291     * Redistributions of source code must retain the above copyright
3292     notice, this list of conditions and the following disclaimer.
3293     * Redistributions in binary form must reproduce the above
3294     copyright notice, this list of conditions and the following disclaimer
3295     in the documentation and/or other materials provided with the
3296     distribution.
3297     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
3298     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
3299     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
3300     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
3301     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
3302     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
3303     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
3304     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
3305     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
3306     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
3307     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
3308 
3309     You can contact the author at :
3310     - zstd source repository : https://github.com/Cyan4973/zstd
3311     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
3312 */
3313 
3314 /* The objects defined into this file should be considered experimental.
3315  * They are not labelled stable, as their prototype may change in the future.
3316  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
3317  */
3318 
3319 /* *************************************
3320 *  Includes
3321 ***************************************/
3322 #include <stdlib.h>
3323 
3324 
3325 /** ************************************************
3326 *  Streaming decompression
3327 *
3328 *  A ZBUFF_DCtx object is required to track streaming operation.
3329 *  Use ZBUFF_createDCtx() and ZBUFF_freeDCtx() to create/release resources.
3330 *  Use ZBUFF_decompressInit() to start a new decompression operation.
3331 *  ZBUFF_DCtx objects can be reused multiple times.
3332 *
3333 *  Use ZBUFF_decompressContinue() repetitively to consume your input.
3334 *  *srcSizePtr and *maxDstSizePtr can be any size.
3335 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *maxDstSizePtr.
3336 *  Note that it may not consume the entire input, in which case it's up to the caller to call again the function with remaining input.
3337 *  The content of dst will be overwritten (up to *maxDstSizePtr) at each function call, so save its content if it matters or change dst .
3338 *  return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
3339 *            or 0 when a frame is completely decoded
3340 *            or an error code, which can be tested using ZBUFF_isError().
3341 *
3342 *  Hint : recommended buffer sizes (not compulsory)
3343 *  output : 128 KB block size is the internal unit, it ensures it's always possible to write a full block when it's decoded.
3344 *  input : just follow indications from ZBUFF_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
3345 * **************************************************/
3346 
3347 typedef enum { ZBUFFds_init, ZBUFFds_readHeader, ZBUFFds_loadHeader, ZBUFFds_decodeHeader,
3348                ZBUFFds_read, ZBUFFds_load, ZBUFFds_flush } ZBUFF_dStage;
3349 
3350 /* *** Resource management *** */
3351 
3352 #define ZSTD_frameHeaderSize_max 5   /* too magical, should come from reference */
3353 struct ZBUFFv04_DCtx_s {
3354     ZSTD_DCtx* zc;
3355     ZSTD_parameters params;
3356     char* inBuff;
3357     size_t inBuffSize;
3358     size_t inPos;
3359     char* outBuff;
3360     size_t outBuffSize;
3361     size_t outStart;
3362     size_t outEnd;
3363     size_t hPos;
3364     const char* dict;
3365     size_t dictSize;
3366     ZBUFF_dStage stage;
3367     unsigned char headerBuffer[ZSTD_frameHeaderSize_max];
3368 };   /* typedef'd to ZBUFF_DCtx within "zstd_buffered.h" */
3369 
3370 typedef ZBUFFv04_DCtx ZBUFF_DCtx;
3371 
3372 
ZBUFF_createDCtx(void)3373 static ZBUFF_DCtx* ZBUFF_createDCtx(void)
3374 {
3375     ZBUFF_DCtx* zbc = (ZBUFF_DCtx*)malloc(sizeof(ZBUFF_DCtx));
3376     if (zbc==NULL) return NULL;
3377     memset(zbc, 0, sizeof(*zbc));
3378     zbc->zc = ZSTD_createDCtx();
3379     zbc->stage = ZBUFFds_init;
3380     return zbc;
3381 }
3382 
ZBUFF_freeDCtx(ZBUFF_DCtx * zbc)3383 static size_t ZBUFF_freeDCtx(ZBUFF_DCtx* zbc)
3384 {
3385     if (zbc==NULL) return 0;   /* support free on null */
3386     ZSTD_freeDCtx(zbc->zc);
3387     free(zbc->inBuff);
3388     free(zbc->outBuff);
3389     free(zbc);
3390     return 0;
3391 }
3392 
3393 
3394 /* *** Initialization *** */
3395 
ZBUFF_decompressInit(ZBUFF_DCtx * zbc)3396 static size_t ZBUFF_decompressInit(ZBUFF_DCtx* zbc)
3397 {
3398     zbc->stage = ZBUFFds_readHeader;
3399     zbc->hPos = zbc->inPos = zbc->outStart = zbc->outEnd = zbc->dictSize = 0;
3400     return ZSTD_resetDCtx(zbc->zc);
3401 }
3402 
3403 
ZBUFF_decompressWithDictionary(ZBUFF_DCtx * zbc,const void * src,size_t srcSize)3404 static size_t ZBUFF_decompressWithDictionary(ZBUFF_DCtx* zbc, const void* src, size_t srcSize)
3405 {
3406     zbc->dict = (const char*)src;
3407     zbc->dictSize = srcSize;
3408     return 0;
3409 }
3410 
ZBUFF_limitCopy(void * dst,size_t maxDstSize,const void * src,size_t srcSize)3411 static size_t ZBUFF_limitCopy(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3412 {
3413     size_t length = MIN(maxDstSize, srcSize);
3414     if (length > 0) {
3415         memcpy(dst, src, length);
3416     }
3417     return length;
3418 }
3419 
3420 /* *** Decompression *** */
3421 
ZBUFF_decompressContinue(ZBUFF_DCtx * zbc,void * dst,size_t * maxDstSizePtr,const void * src,size_t * srcSizePtr)3422 static size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbc, void* dst, size_t* maxDstSizePtr, const void* src, size_t* srcSizePtr)
3423 {
3424     const char* const istart = (const char*)src;
3425     const char* ip = istart;
3426     const char* const iend = istart + *srcSizePtr;
3427     char* const ostart = (char*)dst;
3428     char* op = ostart;
3429     char* const oend = ostart + *maxDstSizePtr;
3430     U32 notDone = 1;
3431 
3432     DEBUGLOG(5, "ZBUFF_decompressContinue");
3433     while (notDone)
3434     {
3435         switch(zbc->stage)
3436         {
3437 
3438         case ZBUFFds_init :
3439             DEBUGLOG(5, "ZBUFF_decompressContinue: stage==ZBUFFds_init => ERROR(init_missing)");
3440             return ERROR(init_missing);
3441 
3442         case ZBUFFds_readHeader :
3443             /* read header from src */
3444             {   size_t const headerSize = ZSTD_getFrameParams(&(zbc->params), src, *srcSizePtr);
3445                 if (ZSTD_isError(headerSize)) return headerSize;
3446                 if (headerSize) {
3447                     /* not enough input to decode header : tell how many bytes would be necessary */
3448                     memcpy(zbc->headerBuffer+zbc->hPos, src, *srcSizePtr);
3449                     zbc->hPos += *srcSizePtr;
3450                     *maxDstSizePtr = 0;
3451                     zbc->stage = ZBUFFds_loadHeader;
3452                     return headerSize - zbc->hPos;
3453                 }
3454                 zbc->stage = ZBUFFds_decodeHeader;
3455                 break;
3456             }
3457 
3458         case ZBUFFds_loadHeader:
3459             /* complete header from src */
3460             {   size_t headerSize = ZBUFF_limitCopy(
3461                     zbc->headerBuffer + zbc->hPos, ZSTD_frameHeaderSize_max - zbc->hPos,
3462                     src, *srcSizePtr);
3463                 zbc->hPos += headerSize;
3464                 ip += headerSize;
3465                 headerSize = ZSTD_getFrameParams(&(zbc->params), zbc->headerBuffer, zbc->hPos);
3466                 if (ZSTD_isError(headerSize)) return headerSize;
3467                 if (headerSize) {
3468                     /* not enough input to decode header : tell how many bytes would be necessary */
3469                     *maxDstSizePtr = 0;
3470                     return headerSize - zbc->hPos;
3471             }   }
3472             /* intentional fallthrough */
3473 
3474         case ZBUFFds_decodeHeader:
3475                 /* apply header to create / resize buffers */
3476                 {   size_t const neededOutSize = (size_t)1 << zbc->params.windowLog;
3477                     size_t const neededInSize = BLOCKSIZE;   /* a block is never > BLOCKSIZE */
3478                     if (zbc->inBuffSize < neededInSize) {
3479                         free(zbc->inBuff);
3480                         zbc->inBuffSize = neededInSize;
3481                         zbc->inBuff = (char*)malloc(neededInSize);
3482                         if (zbc->inBuff == NULL) return ERROR(memory_allocation);
3483                     }
3484                     if (zbc->outBuffSize < neededOutSize) {
3485                         free(zbc->outBuff);
3486                         zbc->outBuffSize = neededOutSize;
3487                         zbc->outBuff = (char*)malloc(neededOutSize);
3488                         if (zbc->outBuff == NULL) return ERROR(memory_allocation);
3489                 }   }
3490                 if (zbc->dictSize)
3491                     ZSTD_decompress_insertDictionary(zbc->zc, zbc->dict, zbc->dictSize);
3492                 if (zbc->hPos) {
3493                     /* some data already loaded into headerBuffer : transfer into inBuff */
3494                     memcpy(zbc->inBuff, zbc->headerBuffer, zbc->hPos);
3495                     zbc->inPos = zbc->hPos;
3496                     zbc->hPos = 0;
3497                     zbc->stage = ZBUFFds_load;
3498                     break;
3499                 }
3500                 zbc->stage = ZBUFFds_read;
3501 		/* fall-through */
3502         case ZBUFFds_read:
3503             {
3504                 size_t neededInSize = ZSTD_nextSrcSizeToDecompress(zbc->zc);
3505                 if (neededInSize==0)   /* end of frame */
3506                 {
3507                     zbc->stage = ZBUFFds_init;
3508                     notDone = 0;
3509                     break;
3510                 }
3511                 if ((size_t)(iend-ip) >= neededInSize)
3512                 {
3513                     /* directly decode from src */
3514                     size_t decodedSize = ZSTD_decompressContinue(zbc->zc,
3515                         zbc->outBuff + zbc->outStart, zbc->outBuffSize - zbc->outStart,
3516                         ip, neededInSize);
3517                     if (ZSTD_isError(decodedSize)) return decodedSize;
3518                     ip += neededInSize;
3519                     if (!decodedSize) break;   /* this was just a header */
3520                     zbc->outEnd = zbc->outStart +  decodedSize;
3521                     zbc->stage = ZBUFFds_flush;
3522                     break;
3523                 }
3524                 if (ip==iend) { notDone = 0; break; }   /* no more input */
3525                 zbc->stage = ZBUFFds_load;
3526             }
3527 	    /* fall-through */
3528         case ZBUFFds_load:
3529             {
3530                 size_t neededInSize = ZSTD_nextSrcSizeToDecompress(zbc->zc);
3531                 size_t toLoad = neededInSize - zbc->inPos;   /* should always be <= remaining space within inBuff */
3532                 size_t loadedSize;
3533                 if (toLoad > zbc->inBuffSize - zbc->inPos) return ERROR(corruption_detected);   /* should never happen */
3534                 loadedSize = ZBUFF_limitCopy(zbc->inBuff + zbc->inPos, toLoad, ip, iend-ip);
3535                 ip += loadedSize;
3536                 zbc->inPos += loadedSize;
3537                 if (loadedSize < toLoad) { notDone = 0; break; }   /* not enough input, wait for more */
3538                 {
3539                     size_t decodedSize = ZSTD_decompressContinue(zbc->zc,
3540                         zbc->outBuff + zbc->outStart, zbc->outBuffSize - zbc->outStart,
3541                         zbc->inBuff, neededInSize);
3542                     if (ZSTD_isError(decodedSize)) return decodedSize;
3543                     zbc->inPos = 0;   /* input is consumed */
3544                     if (!decodedSize) { zbc->stage = ZBUFFds_read; break; }   /* this was just a header */
3545                     zbc->outEnd = zbc->outStart +  decodedSize;
3546                     zbc->stage = ZBUFFds_flush;
3547                     /* ZBUFFds_flush follows */
3548                 }
3549             }
3550 	    /* fall-through */
3551         case ZBUFFds_flush:
3552             {
3553                 size_t toFlushSize = zbc->outEnd - zbc->outStart;
3554                 size_t flushedSize = ZBUFF_limitCopy(op, oend-op, zbc->outBuff + zbc->outStart, toFlushSize);
3555                 op += flushedSize;
3556                 zbc->outStart += flushedSize;
3557                 if (flushedSize == toFlushSize)
3558                 {
3559                     zbc->stage = ZBUFFds_read;
3560                     if (zbc->outStart + BLOCKSIZE > zbc->outBuffSize)
3561                         zbc->outStart = zbc->outEnd = 0;
3562                     break;
3563                 }
3564                 /* cannot flush everything */
3565                 notDone = 0;
3566                 break;
3567             }
3568         default: return ERROR(GENERIC);   /* impossible */
3569         }
3570     }
3571 
3572     *srcSizePtr = ip-istart;
3573     *maxDstSizePtr = op-ostart;
3574 
3575     {
3576         size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zbc->zc);
3577         if (nextSrcSizeHint > 3) nextSrcSizeHint+= 3;   /* get the next block header while at it */
3578         nextSrcSizeHint -= zbc->inPos;   /* already loaded*/
3579         return nextSrcSizeHint;
3580     }
3581 }
3582 
3583 
3584 /* *************************************
3585 *  Tool functions
3586 ***************************************/
ZBUFFv04_isError(size_t errorCode)3587 unsigned ZBUFFv04_isError(size_t errorCode) { return ERR_isError(errorCode); }
ZBUFFv04_getErrorName(size_t errorCode)3588 const char* ZBUFFv04_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
3589 
ZBUFFv04_recommendedDInSize()3590 size_t ZBUFFv04_recommendedDInSize()  { return BLOCKSIZE + 3; }
ZBUFFv04_recommendedDOutSize()3591 size_t ZBUFFv04_recommendedDOutSize() { return BLOCKSIZE; }
3592 
3593 
3594 
3595 /*- ========================================================================= -*/
3596 
3597 /* final wrapping stage */
3598 
ZSTDv04_decompressDCtx(ZSTD_DCtx * dctx,void * dst,size_t maxDstSize,const void * src,size_t srcSize)3599 size_t ZSTDv04_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3600 {
3601     return ZSTD_decompress_usingDict(dctx, dst, maxDstSize, src, srcSize, NULL, 0);
3602 }
3603 
ZSTDv04_decompress(void * dst,size_t maxDstSize,const void * src,size_t srcSize)3604 size_t ZSTDv04_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3605 {
3606 #if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE==1)
3607     size_t regenSize;
3608     ZSTD_DCtx* dctx = ZSTD_createDCtx();
3609     if (dctx==NULL) return ERROR(memory_allocation);
3610     regenSize = ZSTDv04_decompressDCtx(dctx, dst, maxDstSize, src, srcSize);
3611     ZSTD_freeDCtx(dctx);
3612     return regenSize;
3613 #else
3614     ZSTD_DCtx dctx;
3615     return ZSTDv04_decompressDCtx(&dctx, dst, maxDstSize, src, srcSize);
3616 #endif
3617 }
3618 
ZSTDv04_resetDCtx(ZSTDv04_Dctx * dctx)3619 size_t ZSTDv04_resetDCtx(ZSTDv04_Dctx* dctx) { return ZSTD_resetDCtx(dctx); }
3620 
ZSTDv04_nextSrcSizeToDecompress(ZSTDv04_Dctx * dctx)3621 size_t ZSTDv04_nextSrcSizeToDecompress(ZSTDv04_Dctx* dctx)
3622 {
3623     return ZSTD_nextSrcSizeToDecompress(dctx);
3624 }
3625 
ZSTDv04_decompressContinue(ZSTDv04_Dctx * dctx,void * dst,size_t maxDstSize,const void * src,size_t srcSize)3626 size_t ZSTDv04_decompressContinue(ZSTDv04_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
3627 {
3628     return ZSTD_decompressContinue(dctx, dst, maxDstSize, src, srcSize);
3629 }
3630 
3631 
3632 
ZBUFFv04_createDCtx(void)3633 ZBUFFv04_DCtx* ZBUFFv04_createDCtx(void) { return ZBUFF_createDCtx(); }
ZBUFFv04_freeDCtx(ZBUFFv04_DCtx * dctx)3634 size_t ZBUFFv04_freeDCtx(ZBUFFv04_DCtx* dctx) { return ZBUFF_freeDCtx(dctx); }
3635 
ZBUFFv04_decompressInit(ZBUFFv04_DCtx * dctx)3636 size_t ZBUFFv04_decompressInit(ZBUFFv04_DCtx* dctx) { return ZBUFF_decompressInit(dctx); }
ZBUFFv04_decompressWithDictionary(ZBUFFv04_DCtx * dctx,const void * src,size_t srcSize)3637 size_t ZBUFFv04_decompressWithDictionary(ZBUFFv04_DCtx* dctx, const void* src, size_t srcSize)
3638 { return ZBUFF_decompressWithDictionary(dctx, src, srcSize); }
3639 
ZBUFFv04_decompressContinue(ZBUFFv04_DCtx * dctx,void * dst,size_t * maxDstSizePtr,const void * src,size_t * srcSizePtr)3640 size_t ZBUFFv04_decompressContinue(ZBUFFv04_DCtx* dctx, void* dst, size_t* maxDstSizePtr, const void* src, size_t* srcSizePtr)
3641 {
3642     DEBUGLOG(5, "ZBUFFv04_decompressContinue");
3643     return ZBUFF_decompressContinue(dctx, dst, maxDstSizePtr, src, srcSizePtr);
3644 }
3645 
ZSTDv04_createDCtx(void)3646 ZSTD_DCtx* ZSTDv04_createDCtx(void) { return ZSTD_createDCtx(); }
ZSTDv04_freeDCtx(ZSTD_DCtx * dctx)3647 size_t ZSTDv04_freeDCtx(ZSTD_DCtx* dctx) { return ZSTD_freeDCtx(dctx); }
3648