xref: /freebsd/sys/contrib/zstd/lib/legacy/zstd_v03.c (revision 052d3c129019c2f03488f7cb7399580091f9a713)
10c16b537SWarner Losh /*
20c16b537SWarner Losh  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
30c16b537SWarner Losh  * All rights reserved.
40c16b537SWarner Losh  *
50c16b537SWarner Losh  * This source code is licensed under both the BSD-style license (found in the
60c16b537SWarner Losh  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
70c16b537SWarner Losh  * in the COPYING file in the root directory of this source tree).
80c16b537SWarner Losh  * You may select, at your option, one of the above-listed licenses.
90c16b537SWarner Losh  */
100c16b537SWarner Losh 
110c16b537SWarner Losh 
120c16b537SWarner Losh #include <stddef.h>    /* size_t, ptrdiff_t */
130c16b537SWarner Losh #include "zstd_v03.h"
140c16b537SWarner Losh #include "error_private.h"
150c16b537SWarner Losh 
160c16b537SWarner Losh 
170c16b537SWarner Losh /******************************************
180c16b537SWarner Losh *  Compiler-specific
190c16b537SWarner Losh ******************************************/
200c16b537SWarner Losh #if defined(_MSC_VER)   /* Visual Studio */
210c16b537SWarner Losh #   include <stdlib.h>  /* _byteswap_ulong */
220c16b537SWarner Losh #   include <intrin.h>  /* _byteswap_* */
230c16b537SWarner Losh #endif
240c16b537SWarner Losh 
250c16b537SWarner Losh 
260c16b537SWarner Losh 
270c16b537SWarner Losh /* ******************************************************************
280c16b537SWarner Losh    mem.h
290c16b537SWarner Losh    low-level memory access routines
300c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet.
310c16b537SWarner Losh 
320c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
330c16b537SWarner Losh 
340c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
350c16b537SWarner Losh    modification, are permitted provided that the following conditions are
360c16b537SWarner Losh    met:
370c16b537SWarner Losh 
380c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
390c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
400c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
410c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
420c16b537SWarner Losh    in the documentation and/or other materials provided with the
430c16b537SWarner Losh    distribution.
440c16b537SWarner Losh 
450c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
460c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
470c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
480c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
490c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
500c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
510c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
520c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
530c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
540c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
550c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
560c16b537SWarner Losh 
570c16b537SWarner Losh     You can contact the author at :
580c16b537SWarner Losh     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
590c16b537SWarner Losh     - Public forum : https://groups.google.com/forum/#!forum/lz4c
600c16b537SWarner Losh ****************************************************************** */
610c16b537SWarner Losh #ifndef MEM_H_MODULE
620c16b537SWarner Losh #define MEM_H_MODULE
630c16b537SWarner Losh 
640c16b537SWarner Losh #if defined (__cplusplus)
650c16b537SWarner Losh extern "C" {
660c16b537SWarner Losh #endif
670c16b537SWarner Losh 
680c16b537SWarner Losh /******************************************
690c16b537SWarner Losh *  Includes
700c16b537SWarner Losh ******************************************/
710c16b537SWarner Losh #include <stddef.h>    /* size_t, ptrdiff_t */
720c16b537SWarner Losh #include <string.h>    /* memcpy */
730c16b537SWarner Losh 
740c16b537SWarner Losh 
750c16b537SWarner Losh /******************************************
760c16b537SWarner Losh *  Compiler-specific
770c16b537SWarner Losh ******************************************/
780c16b537SWarner Losh #if defined(__GNUC__)
790c16b537SWarner Losh #  define MEM_STATIC static __attribute__((unused))
800c16b537SWarner Losh #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
810c16b537SWarner Losh #  define MEM_STATIC static inline
820c16b537SWarner Losh #elif defined(_MSC_VER)
830c16b537SWarner Losh #  define MEM_STATIC static __inline
840c16b537SWarner Losh #else
850c16b537SWarner Losh #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
860c16b537SWarner Losh #endif
870c16b537SWarner Losh 
880c16b537SWarner Losh 
890c16b537SWarner Losh /****************************************************************
900c16b537SWarner Losh *  Basic Types
910c16b537SWarner Losh *****************************************************************/
920c16b537SWarner Losh #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
930c16b537SWarner Losh # include <stdint.h>
940c16b537SWarner Losh   typedef  uint8_t BYTE;
950c16b537SWarner Losh   typedef uint16_t U16;
960c16b537SWarner Losh   typedef  int16_t S16;
970c16b537SWarner Losh   typedef uint32_t U32;
980c16b537SWarner Losh   typedef  int32_t S32;
990c16b537SWarner Losh   typedef uint64_t U64;
1000c16b537SWarner Losh   typedef  int64_t S64;
1010c16b537SWarner Losh #else
1020c16b537SWarner Losh   typedef unsigned char       BYTE;
1030c16b537SWarner Losh   typedef unsigned short      U16;
1040c16b537SWarner Losh   typedef   signed short      S16;
1050c16b537SWarner Losh   typedef unsigned int        U32;
1060c16b537SWarner Losh   typedef   signed int        S32;
1070c16b537SWarner Losh   typedef unsigned long long  U64;
1080c16b537SWarner Losh   typedef   signed long long  S64;
1090c16b537SWarner Losh #endif
1100c16b537SWarner Losh 
1110c16b537SWarner Losh 
1120c16b537SWarner Losh /****************************************************************
1130c16b537SWarner Losh *  Memory I/O
1140c16b537SWarner Losh *****************************************************************/
1150c16b537SWarner Losh /* MEM_FORCE_MEMORY_ACCESS
1160c16b537SWarner Losh  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
1170c16b537SWarner Losh  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
1180c16b537SWarner Losh  * The below switch allow to select different access method for improved performance.
1190c16b537SWarner Losh  * Method 0 (default) : use `memcpy()`. Safe and portable.
1200c16b537SWarner Losh  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
1210c16b537SWarner Losh  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
1220c16b537SWarner Losh  * Method 2 : direct access. This method is portable but violate C standard.
1230c16b537SWarner Losh  *            It can generate buggy code on targets generating assembly depending on alignment.
1240c16b537SWarner Losh  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
1250c16b537SWarner Losh  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
1260c16b537SWarner Losh  * Prefer these methods in priority order (0 > 1 > 2)
1270c16b537SWarner Losh  */
1280c16b537SWarner Losh #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
1290c16b537SWarner Losh #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
1300c16b537SWarner Losh #    define MEM_FORCE_MEMORY_ACCESS 2
1310c16b537SWarner Losh #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
1320c16b537SWarner Losh   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
1330c16b537SWarner Losh #    define MEM_FORCE_MEMORY_ACCESS 1
1340c16b537SWarner Losh #  endif
1350c16b537SWarner Losh #endif
1360c16b537SWarner Losh 
1370c16b537SWarner Losh MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
1380c16b537SWarner Losh MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
1390c16b537SWarner Losh 
1400c16b537SWarner Losh MEM_STATIC unsigned MEM_isLittleEndian(void)
1410c16b537SWarner Losh {
1420c16b537SWarner Losh     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
1430c16b537SWarner Losh     return one.c[0];
1440c16b537SWarner Losh }
1450c16b537SWarner Losh 
1460c16b537SWarner Losh #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
1470c16b537SWarner Losh 
1480c16b537SWarner Losh /* violates C standard on structure alignment.
1490c16b537SWarner Losh Only use if no other choice to achieve best performance on target platform */
1500c16b537SWarner Losh MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
1510c16b537SWarner Losh MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
1520c16b537SWarner Losh MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
1530c16b537SWarner Losh 
1540c16b537SWarner Losh MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
1550c16b537SWarner Losh 
1560c16b537SWarner Losh #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
1570c16b537SWarner Losh 
1580c16b537SWarner Losh /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
1590c16b537SWarner Losh /* currently only defined for gcc and icc */
1600c16b537SWarner Losh typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
1610c16b537SWarner Losh 
1620c16b537SWarner Losh MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
1630c16b537SWarner Losh MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
1640c16b537SWarner Losh MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
1650c16b537SWarner Losh 
1660c16b537SWarner Losh MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
1670c16b537SWarner Losh 
1680c16b537SWarner Losh #else
1690c16b537SWarner Losh 
1700c16b537SWarner Losh /* default method, safe and standard.
1710c16b537SWarner Losh    can sometimes prove slower */
1720c16b537SWarner Losh 
1730c16b537SWarner Losh MEM_STATIC U16 MEM_read16(const void* memPtr)
1740c16b537SWarner Losh {
1750c16b537SWarner Losh     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
1760c16b537SWarner Losh }
1770c16b537SWarner Losh 
1780c16b537SWarner Losh MEM_STATIC U32 MEM_read32(const void* memPtr)
1790c16b537SWarner Losh {
1800c16b537SWarner Losh     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
1810c16b537SWarner Losh }
1820c16b537SWarner Losh 
1830c16b537SWarner Losh MEM_STATIC U64 MEM_read64(const void* memPtr)
1840c16b537SWarner Losh {
1850c16b537SWarner Losh     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
1860c16b537SWarner Losh }
1870c16b537SWarner Losh 
1880c16b537SWarner Losh MEM_STATIC void MEM_write16(void* memPtr, U16 value)
1890c16b537SWarner Losh {
1900c16b537SWarner Losh     memcpy(memPtr, &value, sizeof(value));
1910c16b537SWarner Losh }
1920c16b537SWarner Losh 
1930c16b537SWarner Losh 
1940c16b537SWarner Losh #endif // MEM_FORCE_MEMORY_ACCESS
1950c16b537SWarner Losh 
1960c16b537SWarner Losh 
1970c16b537SWarner Losh MEM_STATIC U16 MEM_readLE16(const void* memPtr)
1980c16b537SWarner Losh {
1990c16b537SWarner Losh     if (MEM_isLittleEndian())
2000c16b537SWarner Losh         return MEM_read16(memPtr);
2010c16b537SWarner Losh     else
2020c16b537SWarner Losh     {
2030c16b537SWarner Losh         const BYTE* p = (const BYTE*)memPtr;
2040c16b537SWarner Losh         return (U16)(p[0] + (p[1]<<8));
2050c16b537SWarner Losh     }
2060c16b537SWarner Losh }
2070c16b537SWarner Losh 
2080c16b537SWarner Losh MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
2090c16b537SWarner Losh {
2100c16b537SWarner Losh     if (MEM_isLittleEndian())
2110c16b537SWarner Losh     {
2120c16b537SWarner Losh         MEM_write16(memPtr, val);
2130c16b537SWarner Losh     }
2140c16b537SWarner Losh     else
2150c16b537SWarner Losh     {
2160c16b537SWarner Losh         BYTE* p = (BYTE*)memPtr;
2170c16b537SWarner Losh         p[0] = (BYTE)val;
2180c16b537SWarner Losh         p[1] = (BYTE)(val>>8);
2190c16b537SWarner Losh     }
2200c16b537SWarner Losh }
2210c16b537SWarner Losh 
2220c16b537SWarner Losh MEM_STATIC U32 MEM_readLE32(const void* memPtr)
2230c16b537SWarner Losh {
2240c16b537SWarner Losh     if (MEM_isLittleEndian())
2250c16b537SWarner Losh         return MEM_read32(memPtr);
2260c16b537SWarner Losh     else
2270c16b537SWarner Losh     {
2280c16b537SWarner Losh         const BYTE* p = (const BYTE*)memPtr;
2290c16b537SWarner Losh         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
2300c16b537SWarner Losh     }
2310c16b537SWarner Losh }
2320c16b537SWarner Losh 
2330c16b537SWarner Losh MEM_STATIC U64 MEM_readLE64(const void* memPtr)
2340c16b537SWarner Losh {
2350c16b537SWarner Losh     if (MEM_isLittleEndian())
2360c16b537SWarner Losh         return MEM_read64(memPtr);
2370c16b537SWarner Losh     else
2380c16b537SWarner Losh     {
2390c16b537SWarner Losh         const BYTE* p = (const BYTE*)memPtr;
2400c16b537SWarner Losh         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
2410c16b537SWarner Losh                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
2420c16b537SWarner Losh     }
2430c16b537SWarner Losh }
2440c16b537SWarner Losh 
2450c16b537SWarner Losh 
2460c16b537SWarner Losh MEM_STATIC size_t MEM_readLEST(const void* memPtr)
2470c16b537SWarner Losh {
2480c16b537SWarner Losh     if (MEM_32bits())
2490c16b537SWarner Losh         return (size_t)MEM_readLE32(memPtr);
2500c16b537SWarner Losh     else
2510c16b537SWarner Losh         return (size_t)MEM_readLE64(memPtr);
2520c16b537SWarner Losh }
2530c16b537SWarner Losh 
2540c16b537SWarner Losh 
2550c16b537SWarner Losh #if defined (__cplusplus)
2560c16b537SWarner Losh }
2570c16b537SWarner Losh #endif
2580c16b537SWarner Losh 
2590c16b537SWarner Losh #endif /* MEM_H_MODULE */
2600c16b537SWarner Losh 
2610c16b537SWarner Losh 
2620c16b537SWarner Losh /* ******************************************************************
2630c16b537SWarner Losh    bitstream
2640c16b537SWarner Losh    Part of NewGen Entropy library
2650c16b537SWarner Losh    header file (to include)
2660c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet.
2670c16b537SWarner Losh 
2680c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
2690c16b537SWarner Losh 
2700c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
2710c16b537SWarner Losh    modification, are permitted provided that the following conditions are
2720c16b537SWarner Losh    met:
2730c16b537SWarner Losh 
2740c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
2750c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
2760c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
2770c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
2780c16b537SWarner Losh    in the documentation and/or other materials provided with the
2790c16b537SWarner Losh    distribution.
2800c16b537SWarner Losh 
2810c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
2820c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2830c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
2840c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
2850c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
2860c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
2870c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
2880c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
2890c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
2900c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
2910c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2920c16b537SWarner Losh 
2930c16b537SWarner Losh    You can contact the author at :
2940c16b537SWarner Losh    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
2950c16b537SWarner Losh    - Public forum : https://groups.google.com/forum/#!forum/lz4c
2960c16b537SWarner Losh ****************************************************************** */
2970c16b537SWarner Losh #ifndef BITSTREAM_H_MODULE
2980c16b537SWarner Losh #define BITSTREAM_H_MODULE
2990c16b537SWarner Losh 
3000c16b537SWarner Losh #if defined (__cplusplus)
3010c16b537SWarner Losh extern "C" {
3020c16b537SWarner Losh #endif
3030c16b537SWarner Losh 
3040c16b537SWarner Losh 
3050c16b537SWarner Losh /*
3060c16b537SWarner Losh *  This API consists of small unitary functions, which highly benefit from being inlined.
3070c16b537SWarner Losh *  Since link-time-optimization is not available for all compilers,
3080c16b537SWarner Losh *  these functions are defined into a .h to be included.
3090c16b537SWarner Losh */
3100c16b537SWarner Losh 
3110c16b537SWarner Losh 
3120c16b537SWarner Losh /**********************************************
3130c16b537SWarner Losh *  bitStream decompression API (read backward)
3140c16b537SWarner Losh **********************************************/
3150c16b537SWarner Losh typedef struct
3160c16b537SWarner Losh {
3170c16b537SWarner Losh     size_t   bitContainer;
3180c16b537SWarner Losh     unsigned bitsConsumed;
3190c16b537SWarner Losh     const char* ptr;
3200c16b537SWarner Losh     const char* start;
3210c16b537SWarner Losh } BIT_DStream_t;
3220c16b537SWarner Losh 
3230c16b537SWarner Losh typedef enum { BIT_DStream_unfinished = 0,
3240c16b537SWarner Losh                BIT_DStream_endOfBuffer = 1,
3250c16b537SWarner Losh                BIT_DStream_completed = 2,
3260c16b537SWarner Losh                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
3270c16b537SWarner Losh                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
3280c16b537SWarner Losh 
3290c16b537SWarner Losh MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
3300c16b537SWarner Losh MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
3310c16b537SWarner Losh MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
3320c16b537SWarner Losh MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
3330c16b537SWarner Losh 
3340c16b537SWarner Losh 
3350c16b537SWarner Losh 
3360c16b537SWarner Losh /******************************************
3370c16b537SWarner Losh *  unsafe API
3380c16b537SWarner Losh ******************************************/
3390c16b537SWarner Losh MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
3400c16b537SWarner Losh /* faster, but works only if nbBits >= 1 */
3410c16b537SWarner Losh 
3420c16b537SWarner Losh 
3430c16b537SWarner Losh 
3440c16b537SWarner Losh /****************************************************************
3450c16b537SWarner Losh *  Helper functions
3460c16b537SWarner Losh ****************************************************************/
347*052d3c12SConrad Meyer MEM_STATIC unsigned BIT_highbit32 (U32 val)
3480c16b537SWarner Losh {
3490c16b537SWarner Losh #   if defined(_MSC_VER)   /* Visual */
3500c16b537SWarner Losh     unsigned long r=0;
3510c16b537SWarner Losh     _BitScanReverse ( &r, val );
3520c16b537SWarner Losh     return (unsigned) r;
3530c16b537SWarner Losh #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
3540c16b537SWarner Losh     return 31 - __builtin_clz (val);
3550c16b537SWarner Losh #   else   /* Software version */
3560c16b537SWarner Losh     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 };
3570c16b537SWarner Losh     U32 v = val;
3580c16b537SWarner Losh     unsigned r;
3590c16b537SWarner Losh     v |= v >> 1;
3600c16b537SWarner Losh     v |= v >> 2;
3610c16b537SWarner Losh     v |= v >> 4;
3620c16b537SWarner Losh     v |= v >> 8;
3630c16b537SWarner Losh     v |= v >> 16;
3640c16b537SWarner Losh     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
3650c16b537SWarner Losh     return r;
3660c16b537SWarner Losh #   endif
3670c16b537SWarner Losh }
3680c16b537SWarner Losh 
3690c16b537SWarner Losh 
3700c16b537SWarner Losh 
3710c16b537SWarner Losh /**********************************************************
3720c16b537SWarner Losh * bitStream decoding
3730c16b537SWarner Losh **********************************************************/
3740c16b537SWarner Losh 
3750c16b537SWarner Losh /*!BIT_initDStream
3760c16b537SWarner Losh *  Initialize a BIT_DStream_t.
3770c16b537SWarner Losh *  @bitD : a pointer to an already allocated BIT_DStream_t structure
3780c16b537SWarner Losh *  @srcBuffer must point at the beginning of a bitStream
3790c16b537SWarner Losh *  @srcSize must be the exact size of the bitStream
3800c16b537SWarner Losh *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
3810c16b537SWarner Losh */
3820c16b537SWarner Losh MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
3830c16b537SWarner Losh {
3840c16b537SWarner Losh     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
3850c16b537SWarner Losh 
3860c16b537SWarner Losh     if (srcSize >=  sizeof(size_t))   /* normal case */
3870c16b537SWarner Losh     {
3880c16b537SWarner Losh         U32 contain32;
3890c16b537SWarner Losh         bitD->start = (const char*)srcBuffer;
3900c16b537SWarner Losh         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
3910c16b537SWarner Losh         bitD->bitContainer = MEM_readLEST(bitD->ptr);
3920c16b537SWarner Losh         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
3930c16b537SWarner Losh         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
3940c16b537SWarner Losh         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
3950c16b537SWarner Losh     }
3960c16b537SWarner Losh     else
3970c16b537SWarner Losh     {
3980c16b537SWarner Losh         U32 contain32;
3990c16b537SWarner Losh         bitD->start = (const char*)srcBuffer;
4000c16b537SWarner Losh         bitD->ptr   = bitD->start;
4010c16b537SWarner Losh         bitD->bitContainer = *(const BYTE*)(bitD->start);
4020c16b537SWarner Losh         switch(srcSize)
4030c16b537SWarner Losh         {
4040c16b537SWarner Losh             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
4050c16b537SWarner Losh             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
4060c16b537SWarner Losh             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
4070c16b537SWarner Losh             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
4080c16b537SWarner Losh             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
4090c16b537SWarner Losh             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
4100c16b537SWarner Losh             default:;
4110c16b537SWarner Losh         }
4120c16b537SWarner Losh         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
4130c16b537SWarner Losh         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
4140c16b537SWarner Losh         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
4150c16b537SWarner Losh         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
4160c16b537SWarner Losh     }
4170c16b537SWarner Losh 
4180c16b537SWarner Losh     return srcSize;
4190c16b537SWarner Losh }
4200c16b537SWarner Losh MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
4210c16b537SWarner Losh {
4220c16b537SWarner Losh     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
4230c16b537SWarner Losh     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
4240c16b537SWarner Losh }
4250c16b537SWarner Losh 
4260c16b537SWarner Losh /*! BIT_lookBitsFast :
4270c16b537SWarner Losh *   unsafe version; only works only if nbBits >= 1 */
4280c16b537SWarner Losh MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
4290c16b537SWarner Losh {
4300c16b537SWarner Losh     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
4310c16b537SWarner Losh     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
4320c16b537SWarner Losh }
4330c16b537SWarner Losh 
4340c16b537SWarner Losh MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
4350c16b537SWarner Losh {
4360c16b537SWarner Losh     bitD->bitsConsumed += nbBits;
4370c16b537SWarner Losh }
4380c16b537SWarner Losh 
4390c16b537SWarner Losh MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
4400c16b537SWarner Losh {
4410c16b537SWarner Losh     size_t value = BIT_lookBits(bitD, nbBits);
4420c16b537SWarner Losh     BIT_skipBits(bitD, nbBits);
4430c16b537SWarner Losh     return value;
4440c16b537SWarner Losh }
4450c16b537SWarner Losh 
4460c16b537SWarner Losh /*!BIT_readBitsFast :
4470c16b537SWarner Losh *  unsafe version; only works only if nbBits >= 1 */
4480c16b537SWarner Losh MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
4490c16b537SWarner Losh {
4500c16b537SWarner Losh     size_t value = BIT_lookBitsFast(bitD, nbBits);
4510c16b537SWarner Losh     BIT_skipBits(bitD, nbBits);
4520c16b537SWarner Losh     return value;
4530c16b537SWarner Losh }
4540c16b537SWarner Losh 
4550c16b537SWarner Losh MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
4560c16b537SWarner Losh {
4570c16b537SWarner Losh     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
4580c16b537SWarner Losh         return BIT_DStream_overflow;
4590c16b537SWarner Losh 
4600c16b537SWarner Losh     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
4610c16b537SWarner Losh     {
4620c16b537SWarner Losh         bitD->ptr -= bitD->bitsConsumed >> 3;
4630c16b537SWarner Losh         bitD->bitsConsumed &= 7;
4640c16b537SWarner Losh         bitD->bitContainer = MEM_readLEST(bitD->ptr);
4650c16b537SWarner Losh         return BIT_DStream_unfinished;
4660c16b537SWarner Losh     }
4670c16b537SWarner Losh     if (bitD->ptr == bitD->start)
4680c16b537SWarner Losh     {
4690c16b537SWarner Losh         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
4700c16b537SWarner Losh         return BIT_DStream_completed;
4710c16b537SWarner Losh     }
4720c16b537SWarner Losh     {
4730c16b537SWarner Losh         U32 nbBytes = bitD->bitsConsumed >> 3;
4740c16b537SWarner Losh         BIT_DStream_status result = BIT_DStream_unfinished;
4750c16b537SWarner Losh         if (bitD->ptr - nbBytes < bitD->start)
4760c16b537SWarner Losh         {
4770c16b537SWarner Losh             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
4780c16b537SWarner Losh             result = BIT_DStream_endOfBuffer;
4790c16b537SWarner Losh         }
4800c16b537SWarner Losh         bitD->ptr -= nbBytes;
4810c16b537SWarner Losh         bitD->bitsConsumed -= nbBytes*8;
4820c16b537SWarner Losh         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
4830c16b537SWarner Losh         return result;
4840c16b537SWarner Losh     }
4850c16b537SWarner Losh }
4860c16b537SWarner Losh 
4870c16b537SWarner Losh /*! BIT_endOfDStream
4880c16b537SWarner Losh *   @return Tells if DStream has reached its exact end
4890c16b537SWarner Losh */
4900c16b537SWarner Losh MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
4910c16b537SWarner Losh {
4920c16b537SWarner Losh     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
4930c16b537SWarner Losh }
4940c16b537SWarner Losh 
4950c16b537SWarner Losh #if defined (__cplusplus)
4960c16b537SWarner Losh }
4970c16b537SWarner Losh #endif
4980c16b537SWarner Losh 
4990c16b537SWarner Losh #endif /* BITSTREAM_H_MODULE */
5000c16b537SWarner Losh /* ******************************************************************
5010c16b537SWarner Losh    Error codes and messages
5020c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet
5030c16b537SWarner Losh 
5040c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
5050c16b537SWarner Losh 
5060c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
5070c16b537SWarner Losh    modification, are permitted provided that the following conditions are
5080c16b537SWarner Losh    met:
5090c16b537SWarner Losh 
5100c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
5110c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
5120c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
5130c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
5140c16b537SWarner Losh    in the documentation and/or other materials provided with the
5150c16b537SWarner Losh    distribution.
5160c16b537SWarner Losh 
5170c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
5180c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
5190c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
5200c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
5210c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
5220c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
5230c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
5240c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
5250c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
5260c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
5270c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5280c16b537SWarner Losh 
5290c16b537SWarner Losh    You can contact the author at :
5300c16b537SWarner Losh    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
5310c16b537SWarner Losh    - Public forum : https://groups.google.com/forum/#!forum/lz4c
5320c16b537SWarner Losh ****************************************************************** */
5330c16b537SWarner Losh #ifndef ERROR_H_MODULE
5340c16b537SWarner Losh #define ERROR_H_MODULE
5350c16b537SWarner Losh 
5360c16b537SWarner Losh #if defined (__cplusplus)
5370c16b537SWarner Losh extern "C" {
5380c16b537SWarner Losh #endif
5390c16b537SWarner Losh 
5400c16b537SWarner Losh 
5410c16b537SWarner Losh /******************************************
5420c16b537SWarner Losh *  Compiler-specific
5430c16b537SWarner Losh ******************************************/
5440c16b537SWarner Losh #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
5450c16b537SWarner Losh #  define ERR_STATIC static inline
5460c16b537SWarner Losh #elif defined(_MSC_VER)
5470c16b537SWarner Losh #  define ERR_STATIC static __inline
5480c16b537SWarner Losh #elif defined(__GNUC__)
5490c16b537SWarner Losh #  define ERR_STATIC static __attribute__((unused))
5500c16b537SWarner Losh #else
5510c16b537SWarner Losh #  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
5520c16b537SWarner Losh #endif
5530c16b537SWarner Losh 
5540c16b537SWarner Losh 
5550c16b537SWarner Losh /******************************************
5560c16b537SWarner Losh *  Error Management
5570c16b537SWarner Losh ******************************************/
5580c16b537SWarner Losh #define PREFIX(name) ZSTD_error_##name
5590c16b537SWarner Losh 
5600c16b537SWarner Losh #define ERROR(name) (size_t)-PREFIX(name)
5610c16b537SWarner Losh 
5620c16b537SWarner Losh #define ERROR_LIST(ITEM) \
5630c16b537SWarner Losh         ITEM(PREFIX(No_Error)) ITEM(PREFIX(GENERIC)) \
5640c16b537SWarner Losh         ITEM(PREFIX(dstSize_tooSmall)) ITEM(PREFIX(srcSize_wrong)) \
5650c16b537SWarner Losh         ITEM(PREFIX(prefix_unknown)) ITEM(PREFIX(corruption_detected)) \
5660c16b537SWarner Losh         ITEM(PREFIX(tableLog_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooSmall)) \
5670c16b537SWarner Losh         ITEM(PREFIX(maxCode))
5680c16b537SWarner Losh 
5690c16b537SWarner Losh #define ERROR_GENERATE_ENUM(ENUM) ENUM,
5700c16b537SWarner Losh typedef enum { ERROR_LIST(ERROR_GENERATE_ENUM) } ERR_codes;  /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
5710c16b537SWarner Losh 
5720c16b537SWarner Losh #define ERROR_CONVERTTOSTRING(STRING) #STRING,
5730c16b537SWarner Losh #define ERROR_GENERATE_STRING(EXPR) ERROR_CONVERTTOSTRING(EXPR)
5740c16b537SWarner Losh static const char* ERR_strings[] = { ERROR_LIST(ERROR_GENERATE_STRING) };
5750c16b537SWarner Losh 
5760c16b537SWarner Losh ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
5770c16b537SWarner Losh 
5780c16b537SWarner Losh ERR_STATIC const char* ERR_getErrorName(size_t code)
5790c16b537SWarner Losh {
5800c16b537SWarner Losh     static const char* codeError = "Unspecified error code";
5810c16b537SWarner Losh     if (ERR_isError(code)) return ERR_strings[-(int)(code)];
5820c16b537SWarner Losh     return codeError;
5830c16b537SWarner Losh }
5840c16b537SWarner Losh 
5850c16b537SWarner Losh 
5860c16b537SWarner Losh #if defined (__cplusplus)
5870c16b537SWarner Losh }
5880c16b537SWarner Losh #endif
5890c16b537SWarner Losh 
5900c16b537SWarner Losh #endif /* ERROR_H_MODULE */
5910c16b537SWarner Losh /*
5920c16b537SWarner Losh Constructor and Destructor of type FSE_CTable
5930c16b537SWarner Losh     Note that its size depends on 'tableLog' and 'maxSymbolValue' */
5940c16b537SWarner Losh typedef unsigned FSE_CTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
5950c16b537SWarner Losh typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
5960c16b537SWarner Losh 
5970c16b537SWarner Losh 
5980c16b537SWarner Losh /* ******************************************************************
5990c16b537SWarner Losh    FSE : Finite State Entropy coder
6000c16b537SWarner Losh    header file for static linking (only)
6010c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet
6020c16b537SWarner Losh 
6030c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
6040c16b537SWarner Losh 
6050c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
6060c16b537SWarner Losh    modification, are permitted provided that the following conditions are
6070c16b537SWarner Losh    met:
6080c16b537SWarner Losh 
6090c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
6100c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
6110c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
6120c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
6130c16b537SWarner Losh    in the documentation and/or other materials provided with the
6140c16b537SWarner Losh    distribution.
6150c16b537SWarner Losh 
6160c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
6170c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
6180c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
6190c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
6200c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
6210c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
6220c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
6230c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
6240c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
6250c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
6260c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
6270c16b537SWarner Losh 
6280c16b537SWarner Losh    You can contact the author at :
6290c16b537SWarner Losh    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
6300c16b537SWarner Losh    - Public forum : https://groups.google.com/forum/#!forum/lz4c
6310c16b537SWarner Losh ****************************************************************** */
6320c16b537SWarner Losh #if defined (__cplusplus)
6330c16b537SWarner Losh extern "C" {
6340c16b537SWarner Losh #endif
6350c16b537SWarner Losh 
6360c16b537SWarner Losh 
6370c16b537SWarner Losh /******************************************
6380c16b537SWarner Losh *  Static allocation
6390c16b537SWarner Losh ******************************************/
6400c16b537SWarner Losh /* FSE buffer bounds */
6410c16b537SWarner Losh #define FSE_NCOUNTBOUND 512
6420c16b537SWarner Losh #define FSE_BLOCKBOUND(size) (size + (size>>7))
6430c16b537SWarner Losh #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
6440c16b537SWarner Losh 
6450c16b537SWarner Losh /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
6460c16b537SWarner Losh #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
6470c16b537SWarner Losh #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<maxTableLog))
6480c16b537SWarner Losh 
6490c16b537SWarner Losh 
6500c16b537SWarner Losh /******************************************
6510c16b537SWarner Losh *  FSE advanced API
6520c16b537SWarner Losh ******************************************/
6530c16b537SWarner Losh static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
6540c16b537SWarner Losh /* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
6550c16b537SWarner Losh 
6560c16b537SWarner Losh static size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
6570c16b537SWarner Losh /* build a fake FSE_DTable, designed to always generate the same symbolValue */
6580c16b537SWarner Losh 
6590c16b537SWarner Losh 
6600c16b537SWarner Losh /******************************************
6610c16b537SWarner Losh *  FSE symbol decompression API
6620c16b537SWarner Losh ******************************************/
6630c16b537SWarner Losh typedef struct
6640c16b537SWarner Losh {
6650c16b537SWarner Losh     size_t      state;
6660c16b537SWarner Losh     const void* table;   /* precise table may vary, depending on U16 */
6670c16b537SWarner Losh } FSE_DState_t;
6680c16b537SWarner Losh 
6690c16b537SWarner Losh 
6700c16b537SWarner Losh static void     FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
6710c16b537SWarner Losh 
6720c16b537SWarner Losh static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
6730c16b537SWarner Losh 
6740c16b537SWarner Losh static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
6750c16b537SWarner Losh 
6760c16b537SWarner Losh 
6770c16b537SWarner Losh /******************************************
6780c16b537SWarner Losh *  FSE unsafe API
6790c16b537SWarner Losh ******************************************/
6800c16b537SWarner Losh static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
6810c16b537SWarner Losh /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
6820c16b537SWarner Losh 
6830c16b537SWarner Losh 
6840c16b537SWarner Losh /******************************************
6850c16b537SWarner Losh *  Implementation of inline functions
6860c16b537SWarner Losh ******************************************/
6870c16b537SWarner Losh 
6880c16b537SWarner Losh /* decompression */
6890c16b537SWarner Losh 
6900c16b537SWarner Losh typedef struct {
6910c16b537SWarner Losh     U16 tableLog;
6920c16b537SWarner Losh     U16 fastMode;
6930c16b537SWarner Losh } FSE_DTableHeader;   /* sizeof U32 */
6940c16b537SWarner Losh 
6950c16b537SWarner Losh typedef struct
6960c16b537SWarner Losh {
6970c16b537SWarner Losh     unsigned short newState;
6980c16b537SWarner Losh     unsigned char  symbol;
6990c16b537SWarner Losh     unsigned char  nbBits;
7000c16b537SWarner Losh } FSE_decode_t;   /* size == U32 */
7010c16b537SWarner Losh 
7020c16b537SWarner Losh MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
7030c16b537SWarner Losh {
7040c16b537SWarner Losh     FSE_DTableHeader DTableH;
7050c16b537SWarner Losh     memcpy(&DTableH, dt, sizeof(DTableH));
7060c16b537SWarner Losh     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
7070c16b537SWarner Losh     BIT_reloadDStream(bitD);
7080c16b537SWarner Losh     DStatePtr->table = dt + 1;
7090c16b537SWarner Losh }
7100c16b537SWarner Losh 
7110c16b537SWarner Losh MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
7120c16b537SWarner Losh {
7130c16b537SWarner Losh     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
7140c16b537SWarner Losh     const U32  nbBits = DInfo.nbBits;
7150c16b537SWarner Losh     BYTE symbol = DInfo.symbol;
7160c16b537SWarner Losh     size_t lowBits = BIT_readBits(bitD, nbBits);
7170c16b537SWarner Losh 
7180c16b537SWarner Losh     DStatePtr->state = DInfo.newState + lowBits;
7190c16b537SWarner Losh     return symbol;
7200c16b537SWarner Losh }
7210c16b537SWarner Losh 
7220c16b537SWarner Losh MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
7230c16b537SWarner Losh {
7240c16b537SWarner Losh     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
7250c16b537SWarner Losh     const U32 nbBits = DInfo.nbBits;
7260c16b537SWarner Losh     BYTE symbol = DInfo.symbol;
7270c16b537SWarner Losh     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
7280c16b537SWarner Losh 
7290c16b537SWarner Losh     DStatePtr->state = DInfo.newState + lowBits;
7300c16b537SWarner Losh     return symbol;
7310c16b537SWarner Losh }
7320c16b537SWarner Losh 
7330c16b537SWarner Losh MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
7340c16b537SWarner Losh {
7350c16b537SWarner Losh     return DStatePtr->state == 0;
7360c16b537SWarner Losh }
7370c16b537SWarner Losh 
7380c16b537SWarner Losh 
7390c16b537SWarner Losh #if defined (__cplusplus)
7400c16b537SWarner Losh }
7410c16b537SWarner Losh #endif
7420c16b537SWarner Losh /* ******************************************************************
7430c16b537SWarner Losh    Huff0 : Huffman coder, part of New Generation Entropy library
7440c16b537SWarner Losh    header file for static linking (only)
7450c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet
7460c16b537SWarner Losh 
7470c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
7480c16b537SWarner Losh 
7490c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
7500c16b537SWarner Losh    modification, are permitted provided that the following conditions are
7510c16b537SWarner Losh    met:
7520c16b537SWarner Losh 
7530c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
7540c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
7550c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
7560c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
7570c16b537SWarner Losh    in the documentation and/or other materials provided with the
7580c16b537SWarner Losh    distribution.
7590c16b537SWarner Losh 
7600c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
7610c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
7620c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
7630c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
7640c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
7650c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
7660c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
7670c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
7680c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
7690c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
7700c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
7710c16b537SWarner Losh 
7720c16b537SWarner Losh    You can contact the author at :
7730c16b537SWarner Losh    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
7740c16b537SWarner Losh    - Public forum : https://groups.google.com/forum/#!forum/lz4c
7750c16b537SWarner Losh ****************************************************************** */
7760c16b537SWarner Losh 
7770c16b537SWarner Losh #if defined (__cplusplus)
7780c16b537SWarner Losh extern "C" {
7790c16b537SWarner Losh #endif
7800c16b537SWarner Losh 
7810c16b537SWarner Losh /******************************************
7820c16b537SWarner Losh *  Static allocation macros
7830c16b537SWarner Losh ******************************************/
7840c16b537SWarner Losh /* Huff0 buffer bounds */
7850c16b537SWarner Losh #define HUF_CTABLEBOUND 129
7860c16b537SWarner Losh #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
7870c16b537SWarner Losh #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
7880c16b537SWarner Losh 
7890c16b537SWarner Losh /* static allocation of Huff0's DTable */
7900c16b537SWarner Losh #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<maxTableLog))  /* nb Cells; use unsigned short for X2, unsigned int for X4 */
7910c16b537SWarner Losh #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
7920c16b537SWarner Losh         unsigned short DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
7930c16b537SWarner Losh #define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
7940c16b537SWarner Losh         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
7950c16b537SWarner Losh #define HUF_CREATE_STATIC_DTABLEX6(DTable, maxTableLog) \
7960c16b537SWarner Losh         unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog) * 3 / 2] = { maxTableLog }
7970c16b537SWarner Losh 
7980c16b537SWarner Losh 
7990c16b537SWarner Losh /******************************************
8000c16b537SWarner Losh *  Advanced functions
8010c16b537SWarner Losh ******************************************/
8020c16b537SWarner Losh static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
8030c16b537SWarner Losh static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbols decoder */
8040c16b537SWarner Losh 
8050c16b537SWarner Losh 
8060c16b537SWarner Losh #if defined (__cplusplus)
8070c16b537SWarner Losh }
8080c16b537SWarner Losh #endif
8090c16b537SWarner Losh 
8100c16b537SWarner Losh /*
8110c16b537SWarner Losh     zstd - standard compression library
8120c16b537SWarner Losh     Header File
8130c16b537SWarner Losh     Copyright (C) 2014-2015, Yann Collet.
8140c16b537SWarner Losh 
8150c16b537SWarner Losh     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
8160c16b537SWarner Losh 
8170c16b537SWarner Losh     Redistribution and use in source and binary forms, with or without
8180c16b537SWarner Losh     modification, are permitted provided that the following conditions are
8190c16b537SWarner Losh     met:
8200c16b537SWarner Losh     * Redistributions of source code must retain the above copyright
8210c16b537SWarner Losh     notice, this list of conditions and the following disclaimer.
8220c16b537SWarner Losh     * Redistributions in binary form must reproduce the above
8230c16b537SWarner Losh     copyright notice, this list of conditions and the following disclaimer
8240c16b537SWarner Losh     in the documentation and/or other materials provided with the
8250c16b537SWarner Losh     distribution.
8260c16b537SWarner Losh     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
8270c16b537SWarner Losh     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
8280c16b537SWarner Losh     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
8290c16b537SWarner Losh     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
8300c16b537SWarner Losh     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
8310c16b537SWarner Losh     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
8320c16b537SWarner Losh     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
8330c16b537SWarner Losh     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
8340c16b537SWarner Losh     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
8350c16b537SWarner Losh     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
8360c16b537SWarner Losh     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
8370c16b537SWarner Losh 
8380c16b537SWarner Losh     You can contact the author at :
8390c16b537SWarner Losh     - zstd source repository : https://github.com/Cyan4973/zstd
8400c16b537SWarner Losh     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
8410c16b537SWarner Losh */
8420c16b537SWarner Losh 
8430c16b537SWarner Losh #if defined (__cplusplus)
8440c16b537SWarner Losh extern "C" {
8450c16b537SWarner Losh #endif
8460c16b537SWarner Losh 
8470c16b537SWarner Losh /* *************************************
8480c16b537SWarner Losh *  Includes
8490c16b537SWarner Losh ***************************************/
8500c16b537SWarner Losh #include <stddef.h>   /* size_t */
8510c16b537SWarner Losh 
8520c16b537SWarner Losh 
8530c16b537SWarner Losh /* *************************************
8540c16b537SWarner Losh *  Version
8550c16b537SWarner Losh ***************************************/
8560c16b537SWarner Losh #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
8570c16b537SWarner Losh #define ZSTD_VERSION_MINOR    2    /* for new (non-breaking) interface capabilities */
8580c16b537SWarner Losh #define ZSTD_VERSION_RELEASE  2    /* for tweaks, bug-fixes, or development */
8590c16b537SWarner Losh #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
8600c16b537SWarner Losh 
8610c16b537SWarner Losh 
8620c16b537SWarner Losh /* *************************************
8630c16b537SWarner Losh *  Advanced functions
8640c16b537SWarner Losh ***************************************/
8650c16b537SWarner Losh typedef struct ZSTD_CCtx_s ZSTD_CCtx;   /* incomplete type */
8660c16b537SWarner Losh 
8670c16b537SWarner Losh #if defined (__cplusplus)
8680c16b537SWarner Losh }
8690c16b537SWarner Losh #endif
8700c16b537SWarner Losh /*
8710c16b537SWarner Losh     zstd - standard compression library
8720c16b537SWarner Losh     Header File for static linking only
8730c16b537SWarner Losh     Copyright (C) 2014-2015, Yann Collet.
8740c16b537SWarner Losh 
8750c16b537SWarner Losh     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
8760c16b537SWarner Losh 
8770c16b537SWarner Losh     Redistribution and use in source and binary forms, with or without
8780c16b537SWarner Losh     modification, are permitted provided that the following conditions are
8790c16b537SWarner Losh     met:
8800c16b537SWarner Losh     * Redistributions of source code must retain the above copyright
8810c16b537SWarner Losh     notice, this list of conditions and the following disclaimer.
8820c16b537SWarner Losh     * Redistributions in binary form must reproduce the above
8830c16b537SWarner Losh     copyright notice, this list of conditions and the following disclaimer
8840c16b537SWarner Losh     in the documentation and/or other materials provided with the
8850c16b537SWarner Losh     distribution.
8860c16b537SWarner Losh     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
8870c16b537SWarner Losh     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
8880c16b537SWarner Losh     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
8890c16b537SWarner Losh     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
8900c16b537SWarner Losh     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
8910c16b537SWarner Losh     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
8920c16b537SWarner Losh     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
8930c16b537SWarner Losh     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
8940c16b537SWarner Losh     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
8950c16b537SWarner Losh     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
8960c16b537SWarner Losh     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
8970c16b537SWarner Losh 
8980c16b537SWarner Losh     You can contact the author at :
8990c16b537SWarner Losh     - zstd source repository : https://github.com/Cyan4973/zstd
9000c16b537SWarner Losh     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
9010c16b537SWarner Losh */
9020c16b537SWarner Losh 
9030c16b537SWarner Losh /* The objects defined into this file should be considered experimental.
9040c16b537SWarner Losh  * They are not labelled stable, as their prototype may change in the future.
9050c16b537SWarner Losh  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
9060c16b537SWarner Losh  */
9070c16b537SWarner Losh 
9080c16b537SWarner Losh #if defined (__cplusplus)
9090c16b537SWarner Losh extern "C" {
9100c16b537SWarner Losh #endif
9110c16b537SWarner Losh 
9120c16b537SWarner Losh /* *************************************
9130c16b537SWarner Losh *  Streaming functions
9140c16b537SWarner Losh ***************************************/
9150c16b537SWarner Losh 
9160c16b537SWarner Losh typedef struct ZSTD_DCtx_s ZSTD_DCtx;
9170c16b537SWarner Losh 
9180c16b537SWarner Losh /*
9190c16b537SWarner Losh   Use above functions alternatively.
9200c16b537SWarner Losh   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
9210c16b537SWarner Losh   ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
9220c16b537SWarner Losh   Result is the number of bytes regenerated within 'dst'.
9230c16b537SWarner Losh   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
9240c16b537SWarner Losh */
9250c16b537SWarner Losh 
9260c16b537SWarner Losh /* *************************************
9270c16b537SWarner Losh *  Prefix - version detection
9280c16b537SWarner Losh ***************************************/
9290c16b537SWarner Losh #define ZSTD_magicNumber 0xFD2FB523   /* v0.3 */
9300c16b537SWarner Losh 
9310c16b537SWarner Losh 
9320c16b537SWarner Losh #if defined (__cplusplus)
9330c16b537SWarner Losh }
9340c16b537SWarner Losh #endif
9350c16b537SWarner Losh /* ******************************************************************
9360c16b537SWarner Losh    FSE : Finite State Entropy coder
9370c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet.
9380c16b537SWarner Losh 
9390c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
9400c16b537SWarner Losh 
9410c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
9420c16b537SWarner Losh    modification, are permitted provided that the following conditions are
9430c16b537SWarner Losh    met:
9440c16b537SWarner Losh 
9450c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
9460c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
9470c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
9480c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
9490c16b537SWarner Losh    in the documentation and/or other materials provided with the
9500c16b537SWarner Losh    distribution.
9510c16b537SWarner Losh 
9520c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
9530c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
9540c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
9550c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
9560c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
9570c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
9580c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
9590c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
9600c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
9610c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
9620c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
9630c16b537SWarner Losh 
9640c16b537SWarner Losh     You can contact the author at :
9650c16b537SWarner Losh     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
9660c16b537SWarner Losh     - Public forum : https://groups.google.com/forum/#!forum/lz4c
9670c16b537SWarner Losh ****************************************************************** */
9680c16b537SWarner Losh 
9690c16b537SWarner Losh #ifndef FSE_COMMONDEFS_ONLY
9700c16b537SWarner Losh 
9710c16b537SWarner Losh /****************************************************************
9720c16b537SWarner Losh *  Tuning parameters
9730c16b537SWarner Losh ****************************************************************/
9740c16b537SWarner Losh /* MEMORY_USAGE :
9750c16b537SWarner Losh *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
9760c16b537SWarner Losh *  Increasing memory usage improves compression ratio
9770c16b537SWarner Losh *  Reduced memory usage can improve speed, due to cache effect
9780c16b537SWarner Losh *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
9790c16b537SWarner Losh #define FSE_MAX_MEMORY_USAGE 14
9800c16b537SWarner Losh #define FSE_DEFAULT_MEMORY_USAGE 13
9810c16b537SWarner Losh 
9820c16b537SWarner Losh /* FSE_MAX_SYMBOL_VALUE :
9830c16b537SWarner Losh *  Maximum symbol value authorized.
9840c16b537SWarner Losh *  Required for proper stack allocation */
9850c16b537SWarner Losh #define FSE_MAX_SYMBOL_VALUE 255
9860c16b537SWarner Losh 
9870c16b537SWarner Losh 
9880c16b537SWarner Losh /****************************************************************
9890c16b537SWarner Losh *  template functions type & suffix
9900c16b537SWarner Losh ****************************************************************/
9910c16b537SWarner Losh #define FSE_FUNCTION_TYPE BYTE
9920c16b537SWarner Losh #define FSE_FUNCTION_EXTENSION
9930c16b537SWarner Losh 
9940c16b537SWarner Losh 
9950c16b537SWarner Losh /****************************************************************
9960c16b537SWarner Losh *  Byte symbol type
9970c16b537SWarner Losh ****************************************************************/
9980c16b537SWarner Losh #endif   /* !FSE_COMMONDEFS_ONLY */
9990c16b537SWarner Losh 
10000c16b537SWarner Losh 
10010c16b537SWarner Losh /****************************************************************
10020c16b537SWarner Losh *  Compiler specifics
10030c16b537SWarner Losh ****************************************************************/
10040c16b537SWarner Losh #ifdef _MSC_VER    /* Visual Studio */
10050c16b537SWarner Losh #  define FORCE_INLINE static __forceinline
10060c16b537SWarner Losh #  include <intrin.h>                    /* For Visual 2005 */
10070c16b537SWarner Losh #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
10080c16b537SWarner Losh #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
10090c16b537SWarner Losh #else
10100c16b537SWarner Losh #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
10110c16b537SWarner Losh #    ifdef __GNUC__
10120c16b537SWarner Losh #      define FORCE_INLINE static inline __attribute__((always_inline))
10130c16b537SWarner Losh #    else
10140c16b537SWarner Losh #      define FORCE_INLINE static inline
10150c16b537SWarner Losh #    endif
10160c16b537SWarner Losh #  else
10170c16b537SWarner Losh #    define FORCE_INLINE static
10180c16b537SWarner Losh #  endif /* __STDC_VERSION__ */
10190c16b537SWarner Losh #endif
10200c16b537SWarner Losh 
10210c16b537SWarner Losh 
10220c16b537SWarner Losh /****************************************************************
10230c16b537SWarner Losh *  Includes
10240c16b537SWarner Losh ****************************************************************/
10250c16b537SWarner Losh #include <stdlib.h>     /* malloc, free, qsort */
10260c16b537SWarner Losh #include <string.h>     /* memcpy, memset */
10270c16b537SWarner Losh #include <stdio.h>      /* printf (debug) */
10280c16b537SWarner Losh 
10290c16b537SWarner Losh /****************************************************************
10300c16b537SWarner Losh *  Constants
10310c16b537SWarner Losh *****************************************************************/
10320c16b537SWarner Losh #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
10330c16b537SWarner Losh #define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
10340c16b537SWarner Losh #define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
10350c16b537SWarner Losh #define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
10360c16b537SWarner Losh #define FSE_MIN_TABLELOG 5
10370c16b537SWarner Losh 
10380c16b537SWarner Losh #define FSE_TABLELOG_ABSOLUTE_MAX 15
10390c16b537SWarner Losh #if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
10400c16b537SWarner Losh #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
10410c16b537SWarner Losh #endif
10420c16b537SWarner Losh 
10430c16b537SWarner Losh 
10440c16b537SWarner Losh /****************************************************************
10450c16b537SWarner Losh *  Error Management
10460c16b537SWarner Losh ****************************************************************/
10470c16b537SWarner Losh #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
10480c16b537SWarner Losh 
10490c16b537SWarner Losh 
10500c16b537SWarner Losh /****************************************************************
10510c16b537SWarner Losh *  Complex types
10520c16b537SWarner Losh ****************************************************************/
10530c16b537SWarner Losh typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
10540c16b537SWarner Losh 
10550c16b537SWarner Losh 
10560c16b537SWarner Losh /****************************************************************
10570c16b537SWarner Losh *  Templates
10580c16b537SWarner Losh ****************************************************************/
10590c16b537SWarner Losh /*
10600c16b537SWarner Losh   designed to be included
10610c16b537SWarner Losh   for type-specific functions (template emulation in C)
10620c16b537SWarner Losh   Objective is to write these functions only once, for improved maintenance
10630c16b537SWarner Losh */
10640c16b537SWarner Losh 
10650c16b537SWarner Losh /* safety checks */
10660c16b537SWarner Losh #ifndef FSE_FUNCTION_EXTENSION
10670c16b537SWarner Losh #  error "FSE_FUNCTION_EXTENSION must be defined"
10680c16b537SWarner Losh #endif
10690c16b537SWarner Losh #ifndef FSE_FUNCTION_TYPE
10700c16b537SWarner Losh #  error "FSE_FUNCTION_TYPE must be defined"
10710c16b537SWarner Losh #endif
10720c16b537SWarner Losh 
10730c16b537SWarner Losh /* Function names */
10740c16b537SWarner Losh #define FSE_CAT(X,Y) X##Y
10750c16b537SWarner Losh #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
10760c16b537SWarner Losh #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
10770c16b537SWarner Losh 
10780c16b537SWarner Losh 
10790c16b537SWarner Losh /* Function templates */
10800c16b537SWarner Losh 
10810c16b537SWarner Losh #define FSE_DECODE_TYPE FSE_decode_t
10820c16b537SWarner Losh 
10830c16b537SWarner Losh static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
10840c16b537SWarner Losh 
10850c16b537SWarner Losh static size_t FSE_buildDTable
10860c16b537SWarner Losh (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
10870c16b537SWarner Losh {
10880c16b537SWarner Losh     void* ptr = dt+1;
10890c16b537SWarner Losh     FSE_DTableHeader DTableH;
10900c16b537SWarner Losh     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)ptr;
10910c16b537SWarner Losh     const U32 tableSize = 1 << tableLog;
10920c16b537SWarner Losh     const U32 tableMask = tableSize-1;
10930c16b537SWarner Losh     const U32 step = FSE_tableStep(tableSize);
10940c16b537SWarner Losh     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
10950c16b537SWarner Losh     U32 position = 0;
10960c16b537SWarner Losh     U32 highThreshold = tableSize-1;
10970c16b537SWarner Losh     const S16 largeLimit= (S16)(1 << (tableLog-1));
10980c16b537SWarner Losh     U32 noLarge = 1;
10990c16b537SWarner Losh     U32 s;
11000c16b537SWarner Losh 
11010c16b537SWarner Losh     /* Sanity Checks */
11020c16b537SWarner Losh     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
11030c16b537SWarner Losh     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
11040c16b537SWarner Losh 
11050c16b537SWarner Losh     /* Init, lay down lowprob symbols */
11060c16b537SWarner Losh     DTableH.tableLog = (U16)tableLog;
11070c16b537SWarner Losh     for (s=0; s<=maxSymbolValue; s++)
11080c16b537SWarner Losh     {
11090c16b537SWarner Losh         if (normalizedCounter[s]==-1)
11100c16b537SWarner Losh         {
11110c16b537SWarner Losh             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
11120c16b537SWarner Losh             symbolNext[s] = 1;
11130c16b537SWarner Losh         }
11140c16b537SWarner Losh         else
11150c16b537SWarner Losh         {
11160c16b537SWarner Losh             if (normalizedCounter[s] >= largeLimit) noLarge=0;
11170c16b537SWarner Losh             symbolNext[s] = normalizedCounter[s];
11180c16b537SWarner Losh         }
11190c16b537SWarner Losh     }
11200c16b537SWarner Losh 
11210c16b537SWarner Losh     /* Spread symbols */
11220c16b537SWarner Losh     for (s=0; s<=maxSymbolValue; s++)
11230c16b537SWarner Losh     {
11240c16b537SWarner Losh         int i;
11250c16b537SWarner Losh         for (i=0; i<normalizedCounter[s]; i++)
11260c16b537SWarner Losh         {
11270c16b537SWarner Losh             tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
11280c16b537SWarner Losh             position = (position + step) & tableMask;
11290c16b537SWarner Losh             while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
11300c16b537SWarner Losh         }
11310c16b537SWarner Losh     }
11320c16b537SWarner Losh 
11330c16b537SWarner Losh     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
11340c16b537SWarner Losh 
11350c16b537SWarner Losh     /* Build Decoding table */
11360c16b537SWarner Losh     {
11370c16b537SWarner Losh         U32 i;
11380c16b537SWarner Losh         for (i=0; i<tableSize; i++)
11390c16b537SWarner Losh         {
11400c16b537SWarner Losh             FSE_FUNCTION_TYPE symbol = (FSE_FUNCTION_TYPE)(tableDecode[i].symbol);
11410c16b537SWarner Losh             U16 nextState = symbolNext[symbol]++;
11420c16b537SWarner Losh             tableDecode[i].nbBits = (BYTE) (tableLog - BIT_highbit32 ((U32)nextState) );
11430c16b537SWarner Losh             tableDecode[i].newState = (U16) ( (nextState << tableDecode[i].nbBits) - tableSize);
11440c16b537SWarner Losh         }
11450c16b537SWarner Losh     }
11460c16b537SWarner Losh 
11470c16b537SWarner Losh     DTableH.fastMode = (U16)noLarge;
11480c16b537SWarner Losh     memcpy(dt, &DTableH, sizeof(DTableH));
11490c16b537SWarner Losh     return 0;
11500c16b537SWarner Losh }
11510c16b537SWarner Losh 
11520c16b537SWarner Losh 
11530c16b537SWarner Losh #ifndef FSE_COMMONDEFS_ONLY
11540c16b537SWarner Losh /******************************************
11550c16b537SWarner Losh *  FSE helper functions
11560c16b537SWarner Losh ******************************************/
11570c16b537SWarner Losh static unsigned FSE_isError(size_t code) { return ERR_isError(code); }
11580c16b537SWarner Losh 
11590c16b537SWarner Losh 
11600c16b537SWarner Losh /****************************************************************
11610c16b537SWarner Losh *  FSE NCount encoding-decoding
11620c16b537SWarner Losh ****************************************************************/
11630c16b537SWarner Losh static short FSE_abs(short a)
11640c16b537SWarner Losh {
11650c16b537SWarner Losh     return a<0 ? -a : a;
11660c16b537SWarner Losh }
11670c16b537SWarner Losh 
11680c16b537SWarner Losh static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
11690c16b537SWarner Losh                  const void* headerBuffer, size_t hbSize)
11700c16b537SWarner Losh {
11710c16b537SWarner Losh     const BYTE* const istart = (const BYTE*) headerBuffer;
11720c16b537SWarner Losh     const BYTE* const iend = istart + hbSize;
11730c16b537SWarner Losh     const BYTE* ip = istart;
11740c16b537SWarner Losh     int nbBits;
11750c16b537SWarner Losh     int remaining;
11760c16b537SWarner Losh     int threshold;
11770c16b537SWarner Losh     U32 bitStream;
11780c16b537SWarner Losh     int bitCount;
11790c16b537SWarner Losh     unsigned charnum = 0;
11800c16b537SWarner Losh     int previous0 = 0;
11810c16b537SWarner Losh 
11820c16b537SWarner Losh     if (hbSize < 4) return ERROR(srcSize_wrong);
11830c16b537SWarner Losh     bitStream = MEM_readLE32(ip);
11840c16b537SWarner Losh     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
11850c16b537SWarner Losh     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
11860c16b537SWarner Losh     bitStream >>= 4;
11870c16b537SWarner Losh     bitCount = 4;
11880c16b537SWarner Losh     *tableLogPtr = nbBits;
11890c16b537SWarner Losh     remaining = (1<<nbBits)+1;
11900c16b537SWarner Losh     threshold = 1<<nbBits;
11910c16b537SWarner Losh     nbBits++;
11920c16b537SWarner Losh 
11930c16b537SWarner Losh     while ((remaining>1) && (charnum<=*maxSVPtr))
11940c16b537SWarner Losh     {
11950c16b537SWarner Losh         if (previous0)
11960c16b537SWarner Losh         {
11970c16b537SWarner Losh             unsigned n0 = charnum;
11980c16b537SWarner Losh             while ((bitStream & 0xFFFF) == 0xFFFF)
11990c16b537SWarner Losh             {
12000c16b537SWarner Losh                 n0+=24;
12010c16b537SWarner Losh                 if (ip < iend-5)
12020c16b537SWarner Losh                 {
12030c16b537SWarner Losh                     ip+=2;
12040c16b537SWarner Losh                     bitStream = MEM_readLE32(ip) >> bitCount;
12050c16b537SWarner Losh                 }
12060c16b537SWarner Losh                 else
12070c16b537SWarner Losh                 {
12080c16b537SWarner Losh                     bitStream >>= 16;
12090c16b537SWarner Losh                     bitCount+=16;
12100c16b537SWarner Losh                 }
12110c16b537SWarner Losh             }
12120c16b537SWarner Losh             while ((bitStream & 3) == 3)
12130c16b537SWarner Losh             {
12140c16b537SWarner Losh                 n0+=3;
12150c16b537SWarner Losh                 bitStream>>=2;
12160c16b537SWarner Losh                 bitCount+=2;
12170c16b537SWarner Losh             }
12180c16b537SWarner Losh             n0 += bitStream & 3;
12190c16b537SWarner Losh             bitCount += 2;
12200c16b537SWarner Losh             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
12210c16b537SWarner Losh             while (charnum < n0) normalizedCounter[charnum++] = 0;
12220c16b537SWarner Losh             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
12230c16b537SWarner Losh             {
12240c16b537SWarner Losh                 ip += bitCount>>3;
12250c16b537SWarner Losh                 bitCount &= 7;
12260c16b537SWarner Losh                 bitStream = MEM_readLE32(ip) >> bitCount;
12270c16b537SWarner Losh             }
12280c16b537SWarner Losh             else
12290c16b537SWarner Losh                 bitStream >>= 2;
12300c16b537SWarner Losh         }
12310c16b537SWarner Losh         {
12320c16b537SWarner Losh             const short max = (short)((2*threshold-1)-remaining);
12330c16b537SWarner Losh             short count;
12340c16b537SWarner Losh 
12350c16b537SWarner Losh             if ((bitStream & (threshold-1)) < (U32)max)
12360c16b537SWarner Losh             {
12370c16b537SWarner Losh                 count = (short)(bitStream & (threshold-1));
12380c16b537SWarner Losh                 bitCount   += nbBits-1;
12390c16b537SWarner Losh             }
12400c16b537SWarner Losh             else
12410c16b537SWarner Losh             {
12420c16b537SWarner Losh                 count = (short)(bitStream & (2*threshold-1));
12430c16b537SWarner Losh                 if (count >= threshold) count -= max;
12440c16b537SWarner Losh                 bitCount   += nbBits;
12450c16b537SWarner Losh             }
12460c16b537SWarner Losh 
12470c16b537SWarner Losh             count--;   /* extra accuracy */
12480c16b537SWarner Losh             remaining -= FSE_abs(count);
12490c16b537SWarner Losh             normalizedCounter[charnum++] = count;
12500c16b537SWarner Losh             previous0 = !count;
12510c16b537SWarner Losh             while (remaining < threshold)
12520c16b537SWarner Losh             {
12530c16b537SWarner Losh                 nbBits--;
12540c16b537SWarner Losh                 threshold >>= 1;
12550c16b537SWarner Losh             }
12560c16b537SWarner Losh 
12570c16b537SWarner Losh             {
12580c16b537SWarner Losh                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
12590c16b537SWarner Losh                 {
12600c16b537SWarner Losh                     ip += bitCount>>3;
12610c16b537SWarner Losh                     bitCount &= 7;
12620c16b537SWarner Losh                 }
12630c16b537SWarner Losh                 else
12640c16b537SWarner Losh                 {
12650c16b537SWarner Losh                     bitCount -= (int)(8 * (iend - 4 - ip));
12660c16b537SWarner Losh                     ip = iend - 4;
12670c16b537SWarner Losh                 }
12680c16b537SWarner Losh                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
12690c16b537SWarner Losh             }
12700c16b537SWarner Losh         }
12710c16b537SWarner Losh     }
12720c16b537SWarner Losh     if (remaining != 1) return ERROR(GENERIC);
12730c16b537SWarner Losh     *maxSVPtr = charnum-1;
12740c16b537SWarner Losh 
12750c16b537SWarner Losh     ip += (bitCount+7)>>3;
12760c16b537SWarner Losh     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
12770c16b537SWarner Losh     return ip-istart;
12780c16b537SWarner Losh }
12790c16b537SWarner Losh 
12800c16b537SWarner Losh 
12810c16b537SWarner Losh /*********************************************************
12820c16b537SWarner Losh *  Decompression (Byte symbols)
12830c16b537SWarner Losh *********************************************************/
12840c16b537SWarner Losh static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
12850c16b537SWarner Losh {
12860c16b537SWarner Losh     void* ptr = dt;
12870c16b537SWarner Losh     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
12880c16b537SWarner Losh     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;
12890c16b537SWarner Losh 
12900c16b537SWarner Losh     DTableH->tableLog = 0;
12910c16b537SWarner Losh     DTableH->fastMode = 0;
12920c16b537SWarner Losh 
12930c16b537SWarner Losh     cell->newState = 0;
12940c16b537SWarner Losh     cell->symbol = symbolValue;
12950c16b537SWarner Losh     cell->nbBits = 0;
12960c16b537SWarner Losh 
12970c16b537SWarner Losh     return 0;
12980c16b537SWarner Losh }
12990c16b537SWarner Losh 
13000c16b537SWarner Losh 
13010c16b537SWarner Losh static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
13020c16b537SWarner Losh {
13030c16b537SWarner Losh     void* ptr = dt;
13040c16b537SWarner Losh     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
13050c16b537SWarner Losh     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;
13060c16b537SWarner Losh     const unsigned tableSize = 1 << nbBits;
13070c16b537SWarner Losh     const unsigned tableMask = tableSize - 1;
13080c16b537SWarner Losh     const unsigned maxSymbolValue = tableMask;
13090c16b537SWarner Losh     unsigned s;
13100c16b537SWarner Losh 
13110c16b537SWarner Losh     /* Sanity checks */
13120c16b537SWarner Losh     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
13130c16b537SWarner Losh 
13140c16b537SWarner Losh     /* Build Decoding Table */
13150c16b537SWarner Losh     DTableH->tableLog = (U16)nbBits;
13160c16b537SWarner Losh     DTableH->fastMode = 1;
13170c16b537SWarner Losh     for (s=0; s<=maxSymbolValue; s++)
13180c16b537SWarner Losh     {
13190c16b537SWarner Losh         dinfo[s].newState = 0;
13200c16b537SWarner Losh         dinfo[s].symbol = (BYTE)s;
13210c16b537SWarner Losh         dinfo[s].nbBits = (BYTE)nbBits;
13220c16b537SWarner Losh     }
13230c16b537SWarner Losh 
13240c16b537SWarner Losh     return 0;
13250c16b537SWarner Losh }
13260c16b537SWarner Losh 
13270c16b537SWarner Losh FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
13280c16b537SWarner Losh           void* dst, size_t maxDstSize,
13290c16b537SWarner Losh     const void* cSrc, size_t cSrcSize,
13300c16b537SWarner Losh     const FSE_DTable* dt, const unsigned fast)
13310c16b537SWarner Losh {
13320c16b537SWarner Losh     BYTE* const ostart = (BYTE*) dst;
13330c16b537SWarner Losh     BYTE* op = ostart;
13340c16b537SWarner Losh     BYTE* const omax = op + maxDstSize;
13350c16b537SWarner Losh     BYTE* const olimit = omax-3;
13360c16b537SWarner Losh 
13370c16b537SWarner Losh     BIT_DStream_t bitD;
13380c16b537SWarner Losh     FSE_DState_t state1;
13390c16b537SWarner Losh     FSE_DState_t state2;
13400c16b537SWarner Losh     size_t errorCode;
13410c16b537SWarner Losh 
13420c16b537SWarner Losh     /* Init */
13430c16b537SWarner Losh     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
13440c16b537SWarner Losh     if (FSE_isError(errorCode)) return errorCode;
13450c16b537SWarner Losh 
13460c16b537SWarner Losh     FSE_initDState(&state1, &bitD, dt);
13470c16b537SWarner Losh     FSE_initDState(&state2, &bitD, dt);
13480c16b537SWarner Losh 
13490c16b537SWarner Losh #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
13500c16b537SWarner Losh 
13510c16b537SWarner Losh     /* 4 symbols per loop */
13520c16b537SWarner Losh     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op<olimit) ; op+=4)
13530c16b537SWarner Losh     {
13540c16b537SWarner Losh         op[0] = FSE_GETSYMBOL(&state1);
13550c16b537SWarner Losh 
13560c16b537SWarner Losh         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
13570c16b537SWarner Losh             BIT_reloadDStream(&bitD);
13580c16b537SWarner Losh 
13590c16b537SWarner Losh         op[1] = FSE_GETSYMBOL(&state2);
13600c16b537SWarner Losh 
13610c16b537SWarner Losh         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
13620c16b537SWarner Losh             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
13630c16b537SWarner Losh 
13640c16b537SWarner Losh         op[2] = FSE_GETSYMBOL(&state1);
13650c16b537SWarner Losh 
13660c16b537SWarner Losh         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
13670c16b537SWarner Losh             BIT_reloadDStream(&bitD);
13680c16b537SWarner Losh 
13690c16b537SWarner Losh         op[3] = FSE_GETSYMBOL(&state2);
13700c16b537SWarner Losh     }
13710c16b537SWarner Losh 
13720c16b537SWarner Losh     /* tail */
13730c16b537SWarner Losh     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
13740c16b537SWarner Losh     while (1)
13750c16b537SWarner Losh     {
13760c16b537SWarner Losh         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
13770c16b537SWarner Losh             break;
13780c16b537SWarner Losh 
13790c16b537SWarner Losh         *op++ = FSE_GETSYMBOL(&state1);
13800c16b537SWarner Losh 
13810c16b537SWarner Losh         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
13820c16b537SWarner Losh             break;
13830c16b537SWarner Losh 
13840c16b537SWarner Losh         *op++ = FSE_GETSYMBOL(&state2);
13850c16b537SWarner Losh     }
13860c16b537SWarner Losh 
13870c16b537SWarner Losh     /* end ? */
13880c16b537SWarner Losh     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
13890c16b537SWarner Losh         return op-ostart;
13900c16b537SWarner Losh 
13910c16b537SWarner Losh     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
13920c16b537SWarner Losh 
13930c16b537SWarner Losh     return ERROR(corruption_detected);
13940c16b537SWarner Losh }
13950c16b537SWarner Losh 
13960c16b537SWarner Losh 
13970c16b537SWarner Losh static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
13980c16b537SWarner Losh                             const void* cSrc, size_t cSrcSize,
13990c16b537SWarner Losh                             const FSE_DTable* dt)
14000c16b537SWarner Losh {
14010c16b537SWarner Losh     FSE_DTableHeader DTableH;
14020c16b537SWarner Losh     memcpy(&DTableH, dt, sizeof(DTableH));
14030c16b537SWarner Losh 
14040c16b537SWarner Losh     /* select fast mode (static) */
14050c16b537SWarner Losh     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
14060c16b537SWarner Losh     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
14070c16b537SWarner Losh }
14080c16b537SWarner Losh 
14090c16b537SWarner Losh 
14100c16b537SWarner Losh static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
14110c16b537SWarner Losh {
14120c16b537SWarner Losh     const BYTE* const istart = (const BYTE*)cSrc;
14130c16b537SWarner Losh     const BYTE* ip = istart;
14140c16b537SWarner Losh     short counting[FSE_MAX_SYMBOL_VALUE+1];
14150c16b537SWarner Losh     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
14160c16b537SWarner Losh     unsigned tableLog;
14170c16b537SWarner Losh     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
14180c16b537SWarner Losh     size_t errorCode;
14190c16b537SWarner Losh 
14200c16b537SWarner Losh     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
14210c16b537SWarner Losh 
14220c16b537SWarner Losh     /* normal FSE decoding mode */
14230c16b537SWarner Losh     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
14240c16b537SWarner Losh     if (FSE_isError(errorCode)) return errorCode;
14250c16b537SWarner Losh     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
14260c16b537SWarner Losh     ip += errorCode;
14270c16b537SWarner Losh     cSrcSize -= errorCode;
14280c16b537SWarner Losh 
14290c16b537SWarner Losh     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
14300c16b537SWarner Losh     if (FSE_isError(errorCode)) return errorCode;
14310c16b537SWarner Losh 
14320c16b537SWarner Losh     /* always return, even if it is an error code */
14330c16b537SWarner Losh     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
14340c16b537SWarner Losh }
14350c16b537SWarner Losh 
14360c16b537SWarner Losh 
14370c16b537SWarner Losh 
14380c16b537SWarner Losh #endif   /* FSE_COMMONDEFS_ONLY */
14390c16b537SWarner Losh /* ******************************************************************
14400c16b537SWarner Losh    Huff0 : Huffman coder, part of New Generation Entropy library
14410c16b537SWarner Losh    Copyright (C) 2013-2015, Yann Collet.
14420c16b537SWarner Losh 
14430c16b537SWarner Losh    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
14440c16b537SWarner Losh 
14450c16b537SWarner Losh    Redistribution and use in source and binary forms, with or without
14460c16b537SWarner Losh    modification, are permitted provided that the following conditions are
14470c16b537SWarner Losh    met:
14480c16b537SWarner Losh 
14490c16b537SWarner Losh        * Redistributions of source code must retain the above copyright
14500c16b537SWarner Losh    notice, this list of conditions and the following disclaimer.
14510c16b537SWarner Losh        * Redistributions in binary form must reproduce the above
14520c16b537SWarner Losh    copyright notice, this list of conditions and the following disclaimer
14530c16b537SWarner Losh    in the documentation and/or other materials provided with the
14540c16b537SWarner Losh    distribution.
14550c16b537SWarner Losh 
14560c16b537SWarner Losh    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
14570c16b537SWarner Losh    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
14580c16b537SWarner Losh    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
14590c16b537SWarner Losh    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
14600c16b537SWarner Losh    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
14610c16b537SWarner Losh    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
14620c16b537SWarner Losh    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
14630c16b537SWarner Losh    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
14640c16b537SWarner Losh    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
14650c16b537SWarner Losh    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
14660c16b537SWarner Losh    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
14670c16b537SWarner Losh 
14680c16b537SWarner Losh     You can contact the author at :
14690c16b537SWarner Losh     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
14700c16b537SWarner Losh     - Public forum : https://groups.google.com/forum/#!forum/lz4c
14710c16b537SWarner Losh ****************************************************************** */
14720c16b537SWarner Losh 
14730c16b537SWarner Losh /****************************************************************
14740c16b537SWarner Losh *  Compiler specifics
14750c16b537SWarner Losh ****************************************************************/
14760c16b537SWarner Losh #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
14770c16b537SWarner Losh /* inline is defined */
14780c16b537SWarner Losh #elif defined(_MSC_VER)
14790c16b537SWarner Losh #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
14800c16b537SWarner Losh #  define inline __inline
14810c16b537SWarner Losh #else
14820c16b537SWarner Losh #  define inline /* disable inline */
14830c16b537SWarner Losh #endif
14840c16b537SWarner Losh 
14850c16b537SWarner Losh 
14860c16b537SWarner Losh /****************************************************************
14870c16b537SWarner Losh *  Includes
14880c16b537SWarner Losh ****************************************************************/
14890c16b537SWarner Losh #include <stdlib.h>     /* malloc, free, qsort */
14900c16b537SWarner Losh #include <string.h>     /* memcpy, memset */
14910c16b537SWarner Losh #include <stdio.h>      /* printf (debug) */
14920c16b537SWarner Losh 
14930c16b537SWarner Losh /****************************************************************
14940c16b537SWarner Losh *  Error Management
14950c16b537SWarner Losh ****************************************************************/
14960c16b537SWarner Losh #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
14970c16b537SWarner Losh 
14980c16b537SWarner Losh 
14990c16b537SWarner Losh /******************************************
15000c16b537SWarner Losh *  Helper functions
15010c16b537SWarner Losh ******************************************/
15020c16b537SWarner Losh static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
15030c16b537SWarner Losh 
15040c16b537SWarner Losh #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
15050c16b537SWarner Losh #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
15060c16b537SWarner Losh #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
15070c16b537SWarner Losh #define HUF_MAX_SYMBOL_VALUE 255
15080c16b537SWarner Losh #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
15090c16b537SWarner Losh #  error "HUF_MAX_TABLELOG is too large !"
15100c16b537SWarner Losh #endif
15110c16b537SWarner Losh 
15120c16b537SWarner Losh 
15130c16b537SWarner Losh 
15140c16b537SWarner Losh /*********************************************************
15150c16b537SWarner Losh *  Huff0 : Huffman block decompression
15160c16b537SWarner Losh *********************************************************/
15170c16b537SWarner Losh typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
15180c16b537SWarner Losh 
15190c16b537SWarner Losh typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
15200c16b537SWarner Losh 
15210c16b537SWarner Losh typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
15220c16b537SWarner Losh 
15230c16b537SWarner Losh /*! HUF_readStats
15240c16b537SWarner Losh     Read compact Huffman tree, saved by HUF_writeCTable
15250c16b537SWarner Losh     @huffWeight : destination buffer
15260c16b537SWarner Losh     @return : size read from `src`
15270c16b537SWarner Losh */
15280c16b537SWarner Losh static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
15290c16b537SWarner Losh                             U32* nbSymbolsPtr, U32* tableLogPtr,
15300c16b537SWarner Losh                             const void* src, size_t srcSize)
15310c16b537SWarner Losh {
15320c16b537SWarner Losh     U32 weightTotal;
15330c16b537SWarner Losh     U32 tableLog;
15340c16b537SWarner Losh     const BYTE* ip = (const BYTE*) src;
15350c16b537SWarner Losh     size_t iSize;
15360c16b537SWarner Losh     size_t oSize;
15370c16b537SWarner Losh     U32 n;
15380c16b537SWarner Losh 
15390c16b537SWarner Losh     if (!srcSize) return ERROR(srcSize_wrong);
15400c16b537SWarner Losh     iSize = ip[0];
15410c16b537SWarner Losh     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
15420c16b537SWarner Losh 
15430c16b537SWarner Losh     if (iSize >= 128)  /* special header */
15440c16b537SWarner Losh     {
15450c16b537SWarner Losh         if (iSize >= (242))   /* RLE */
15460c16b537SWarner Losh         {
15470c16b537SWarner Losh             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
15480c16b537SWarner Losh             oSize = l[iSize-242];
15490c16b537SWarner Losh             memset(huffWeight, 1, hwSize);
15500c16b537SWarner Losh             iSize = 0;
15510c16b537SWarner Losh         }
15520c16b537SWarner Losh         else   /* Incompressible */
15530c16b537SWarner Losh         {
15540c16b537SWarner Losh             oSize = iSize - 127;
15550c16b537SWarner Losh             iSize = ((oSize+1)/2);
15560c16b537SWarner Losh             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
15570c16b537SWarner Losh             if (oSize >= hwSize) return ERROR(corruption_detected);
15580c16b537SWarner Losh             ip += 1;
15590c16b537SWarner Losh             for (n=0; n<oSize; n+=2)
15600c16b537SWarner Losh             {
15610c16b537SWarner Losh                 huffWeight[n]   = ip[n/2] >> 4;
15620c16b537SWarner Losh                 huffWeight[n+1] = ip[n/2] & 15;
15630c16b537SWarner Losh             }
15640c16b537SWarner Losh         }
15650c16b537SWarner Losh     }
15660c16b537SWarner Losh     else  /* header compressed with FSE (normal case) */
15670c16b537SWarner Losh     {
15680c16b537SWarner Losh         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
15690c16b537SWarner Losh         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
15700c16b537SWarner Losh         if (FSE_isError(oSize)) return oSize;
15710c16b537SWarner Losh     }
15720c16b537SWarner Losh 
15730c16b537SWarner Losh     /* collect weight stats */
15740c16b537SWarner Losh     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
15750c16b537SWarner Losh     weightTotal = 0;
15760c16b537SWarner Losh     for (n=0; n<oSize; n++)
15770c16b537SWarner Losh     {
15780c16b537SWarner Losh         if (huffWeight[n] >= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
15790c16b537SWarner Losh         rankStats[huffWeight[n]]++;
15800c16b537SWarner Losh         weightTotal += (1 << huffWeight[n]) >> 1;
15810c16b537SWarner Losh     }
15820c16b537SWarner Losh     if (weightTotal == 0) return ERROR(corruption_detected);
15830c16b537SWarner Losh 
15840c16b537SWarner Losh     /* get last non-null symbol weight (implied, total must be 2^n) */
15850c16b537SWarner Losh     tableLog = BIT_highbit32(weightTotal) + 1;
15860c16b537SWarner Losh     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
15870c16b537SWarner Losh     {
15880c16b537SWarner Losh         U32 total = 1 << tableLog;
15890c16b537SWarner Losh         U32 rest = total - weightTotal;
15900c16b537SWarner Losh         U32 verif = 1 << BIT_highbit32(rest);
15910c16b537SWarner Losh         U32 lastWeight = BIT_highbit32(rest) + 1;
15920c16b537SWarner Losh         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
15930c16b537SWarner Losh         huffWeight[oSize] = (BYTE)lastWeight;
15940c16b537SWarner Losh         rankStats[lastWeight]++;
15950c16b537SWarner Losh     }
15960c16b537SWarner Losh 
15970c16b537SWarner Losh     /* check tree construction validity */
15980c16b537SWarner Losh     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
15990c16b537SWarner Losh 
16000c16b537SWarner Losh     /* results */
16010c16b537SWarner Losh     *nbSymbolsPtr = (U32)(oSize+1);
16020c16b537SWarner Losh     *tableLogPtr = tableLog;
16030c16b537SWarner Losh     return iSize+1;
16040c16b537SWarner Losh }
16050c16b537SWarner Losh 
16060c16b537SWarner Losh 
16070c16b537SWarner Losh /**************************/
16080c16b537SWarner Losh /* single-symbol decoding */
16090c16b537SWarner Losh /**************************/
16100c16b537SWarner Losh 
16110c16b537SWarner Losh static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
16120c16b537SWarner Losh {
16130c16b537SWarner Losh     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
16140c16b537SWarner Losh     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
16150c16b537SWarner Losh     U32 tableLog = 0;
16160c16b537SWarner Losh     const BYTE* ip = (const BYTE*) src;
16170c16b537SWarner Losh     size_t iSize = ip[0];
16180c16b537SWarner Losh     U32 nbSymbols = 0;
16190c16b537SWarner Losh     U32 n;
16200c16b537SWarner Losh     U32 nextRankStart;
16210c16b537SWarner Losh     void* ptr = DTable+1;
16220c16b537SWarner Losh     HUF_DEltX2* const dt = (HUF_DEltX2*)(ptr);
16230c16b537SWarner Losh 
16240c16b537SWarner Losh     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
16250c16b537SWarner Losh     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
16260c16b537SWarner Losh 
16270c16b537SWarner Losh     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
16280c16b537SWarner Losh     if (HUF_isError(iSize)) return iSize;
16290c16b537SWarner Losh 
16300c16b537SWarner Losh     /* check result */
16310c16b537SWarner Losh     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
16320c16b537SWarner Losh     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
16330c16b537SWarner Losh 
16340c16b537SWarner Losh     /* Prepare ranks */
16350c16b537SWarner Losh     nextRankStart = 0;
16360c16b537SWarner Losh     for (n=1; n<=tableLog; n++)
16370c16b537SWarner Losh     {
16380c16b537SWarner Losh         U32 current = nextRankStart;
16390c16b537SWarner Losh         nextRankStart += (rankVal[n] << (n-1));
16400c16b537SWarner Losh         rankVal[n] = current;
16410c16b537SWarner Losh     }
16420c16b537SWarner Losh 
16430c16b537SWarner Losh     /* fill DTable */
16440c16b537SWarner Losh     for (n=0; n<nbSymbols; n++)
16450c16b537SWarner Losh     {
16460c16b537SWarner Losh         const U32 w = huffWeight[n];
16470c16b537SWarner Losh         const U32 length = (1 << w) >> 1;
16480c16b537SWarner Losh         U32 i;
16490c16b537SWarner Losh         HUF_DEltX2 D;
16500c16b537SWarner Losh         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
16510c16b537SWarner Losh         for (i = rankVal[w]; i < rankVal[w] + length; i++)
16520c16b537SWarner Losh             dt[i] = D;
16530c16b537SWarner Losh         rankVal[w] += length;
16540c16b537SWarner Losh     }
16550c16b537SWarner Losh 
16560c16b537SWarner Losh     return iSize;
16570c16b537SWarner Losh }
16580c16b537SWarner Losh 
16590c16b537SWarner Losh static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
16600c16b537SWarner Losh {
16610c16b537SWarner Losh         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
16620c16b537SWarner Losh         const BYTE c = dt[val].byte;
16630c16b537SWarner Losh         BIT_skipBits(Dstream, dt[val].nbBits);
16640c16b537SWarner Losh         return c;
16650c16b537SWarner Losh }
16660c16b537SWarner Losh 
16670c16b537SWarner Losh #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
16680c16b537SWarner Losh     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
16690c16b537SWarner Losh 
16700c16b537SWarner Losh #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
16710c16b537SWarner Losh     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
16720c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
16730c16b537SWarner Losh 
16740c16b537SWarner Losh #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
16750c16b537SWarner Losh     if (MEM_64bits()) \
16760c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
16770c16b537SWarner Losh 
16780c16b537SWarner Losh static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
16790c16b537SWarner Losh {
16800c16b537SWarner Losh     BYTE* const pStart = p;
16810c16b537SWarner Losh 
16820c16b537SWarner Losh     /* up to 4 symbols at a time */
16830c16b537SWarner Losh     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
16840c16b537SWarner Losh     {
16850c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
16860c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
16870c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
16880c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
16890c16b537SWarner Losh     }
16900c16b537SWarner Losh 
16910c16b537SWarner Losh     /* closer to the end */
16920c16b537SWarner Losh     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
16930c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
16940c16b537SWarner Losh 
16950c16b537SWarner Losh     /* no more data to retrieve from bitstream, hence no need to reload */
16960c16b537SWarner Losh     while (p < pEnd)
16970c16b537SWarner Losh         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
16980c16b537SWarner Losh 
16990c16b537SWarner Losh     return pEnd-pStart;
17000c16b537SWarner Losh }
17010c16b537SWarner Losh 
17020c16b537SWarner Losh 
17030c16b537SWarner Losh static size_t HUF_decompress4X2_usingDTable(
17040c16b537SWarner Losh           void* dst,  size_t dstSize,
17050c16b537SWarner Losh     const void* cSrc, size_t cSrcSize,
17060c16b537SWarner Losh     const U16* DTable)
17070c16b537SWarner Losh {
17080c16b537SWarner Losh     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
17090c16b537SWarner Losh 
17100c16b537SWarner Losh     {
17110c16b537SWarner Losh         const BYTE* const istart = (const BYTE*) cSrc;
17120c16b537SWarner Losh         BYTE* const ostart = (BYTE*) dst;
17130c16b537SWarner Losh         BYTE* const oend = ostart + dstSize;
17140c16b537SWarner Losh 
17150c16b537SWarner Losh         const void* ptr = DTable;
17160c16b537SWarner Losh         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)ptr) +1;
17170c16b537SWarner Losh         const U32 dtLog = DTable[0];
17180c16b537SWarner Losh         size_t errorCode;
17190c16b537SWarner Losh 
17200c16b537SWarner Losh         /* Init */
17210c16b537SWarner Losh         BIT_DStream_t bitD1;
17220c16b537SWarner Losh         BIT_DStream_t bitD2;
17230c16b537SWarner Losh         BIT_DStream_t bitD3;
17240c16b537SWarner Losh         BIT_DStream_t bitD4;
17250c16b537SWarner Losh         const size_t length1 = MEM_readLE16(istart);
17260c16b537SWarner Losh         const size_t length2 = MEM_readLE16(istart+2);
17270c16b537SWarner Losh         const size_t length3 = MEM_readLE16(istart+4);
17280c16b537SWarner Losh         size_t length4;
17290c16b537SWarner Losh         const BYTE* const istart1 = istart + 6;  /* jumpTable */
17300c16b537SWarner Losh         const BYTE* const istart2 = istart1 + length1;
17310c16b537SWarner Losh         const BYTE* const istart3 = istart2 + length2;
17320c16b537SWarner Losh         const BYTE* const istart4 = istart3 + length3;
17330c16b537SWarner Losh         const size_t segmentSize = (dstSize+3) / 4;
17340c16b537SWarner Losh         BYTE* const opStart2 = ostart + segmentSize;
17350c16b537SWarner Losh         BYTE* const opStart3 = opStart2 + segmentSize;
17360c16b537SWarner Losh         BYTE* const opStart4 = opStart3 + segmentSize;
17370c16b537SWarner Losh         BYTE* op1 = ostart;
17380c16b537SWarner Losh         BYTE* op2 = opStart2;
17390c16b537SWarner Losh         BYTE* op3 = opStart3;
17400c16b537SWarner Losh         BYTE* op4 = opStart4;
17410c16b537SWarner Losh         U32 endSignal;
17420c16b537SWarner Losh 
17430c16b537SWarner Losh         length4 = cSrcSize - (length1 + length2 + length3 + 6);
17440c16b537SWarner Losh         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
17450c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD1, istart1, length1);
17460c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
17470c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD2, istart2, length2);
17480c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
17490c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD3, istart3, length3);
17500c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
17510c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD4, istart4, length4);
17520c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
17530c16b537SWarner Losh 
17540c16b537SWarner Losh         /* 16-32 symbols per loop (4-8 symbols per stream) */
17550c16b537SWarner Losh         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
17560c16b537SWarner Losh         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
17570c16b537SWarner Losh         {
17580c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
17590c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
17600c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
17610c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
17620c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
17630c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
17640c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
17650c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
17660c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
17670c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
17680c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
17690c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
17700c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
17710c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
17720c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
17730c16b537SWarner Losh             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
17740c16b537SWarner Losh 
17750c16b537SWarner Losh             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
17760c16b537SWarner Losh         }
17770c16b537SWarner Losh 
17780c16b537SWarner Losh         /* check corruption */
17790c16b537SWarner Losh         if (op1 > opStart2) return ERROR(corruption_detected);
17800c16b537SWarner Losh         if (op2 > opStart3) return ERROR(corruption_detected);
17810c16b537SWarner Losh         if (op3 > opStart4) return ERROR(corruption_detected);
17820c16b537SWarner Losh         /* note : op4 supposed already verified within main loop */
17830c16b537SWarner Losh 
17840c16b537SWarner Losh         /* finish bitStreams one by one */
17850c16b537SWarner Losh         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
17860c16b537SWarner Losh         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
17870c16b537SWarner Losh         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
17880c16b537SWarner Losh         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
17890c16b537SWarner Losh 
17900c16b537SWarner Losh         /* check */
17910c16b537SWarner Losh         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
17920c16b537SWarner Losh         if (!endSignal) return ERROR(corruption_detected);
17930c16b537SWarner Losh 
17940c16b537SWarner Losh         /* decoded size */
17950c16b537SWarner Losh         return dstSize;
17960c16b537SWarner Losh     }
17970c16b537SWarner Losh }
17980c16b537SWarner Losh 
17990c16b537SWarner Losh 
18000c16b537SWarner Losh static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
18010c16b537SWarner Losh {
18020c16b537SWarner Losh     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
18030c16b537SWarner Losh     const BYTE* ip = (const BYTE*) cSrc;
18040c16b537SWarner Losh     size_t errorCode;
18050c16b537SWarner Losh 
18060c16b537SWarner Losh     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
18070c16b537SWarner Losh     if (HUF_isError(errorCode)) return errorCode;
18080c16b537SWarner Losh     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
18090c16b537SWarner Losh     ip += errorCode;
18100c16b537SWarner Losh     cSrcSize -= errorCode;
18110c16b537SWarner Losh 
18120c16b537SWarner Losh     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
18130c16b537SWarner Losh }
18140c16b537SWarner Losh 
18150c16b537SWarner Losh 
18160c16b537SWarner Losh /***************************/
18170c16b537SWarner Losh /* double-symbols decoding */
18180c16b537SWarner Losh /***************************/
18190c16b537SWarner Losh 
18200c16b537SWarner Losh static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
18210c16b537SWarner Losh                            const U32* rankValOrigin, const int minWeight,
18220c16b537SWarner Losh                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
18230c16b537SWarner Losh                            U32 nbBitsBaseline, U16 baseSeq)
18240c16b537SWarner Losh {
18250c16b537SWarner Losh     HUF_DEltX4 DElt;
18260c16b537SWarner Losh     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
18270c16b537SWarner Losh     U32 s;
18280c16b537SWarner Losh 
18290c16b537SWarner Losh     /* get pre-calculated rankVal */
18300c16b537SWarner Losh     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
18310c16b537SWarner Losh 
18320c16b537SWarner Losh     /* fill skipped values */
18330c16b537SWarner Losh     if (minWeight>1)
18340c16b537SWarner Losh     {
18350c16b537SWarner Losh         U32 i, skipSize = rankVal[minWeight];
18360c16b537SWarner Losh         MEM_writeLE16(&(DElt.sequence), baseSeq);
18370c16b537SWarner Losh         DElt.nbBits   = (BYTE)(consumed);
18380c16b537SWarner Losh         DElt.length   = 1;
18390c16b537SWarner Losh         for (i = 0; i < skipSize; i++)
18400c16b537SWarner Losh             DTable[i] = DElt;
18410c16b537SWarner Losh     }
18420c16b537SWarner Losh 
18430c16b537SWarner Losh     /* fill DTable */
18440c16b537SWarner Losh     for (s=0; s<sortedListSize; s++)   /* note : sortedSymbols already skipped */
18450c16b537SWarner Losh     {
18460c16b537SWarner Losh         const U32 symbol = sortedSymbols[s].symbol;
18470c16b537SWarner Losh         const U32 weight = sortedSymbols[s].weight;
18480c16b537SWarner Losh         const U32 nbBits = nbBitsBaseline - weight;
18490c16b537SWarner Losh         const U32 length = 1 << (sizeLog-nbBits);
18500c16b537SWarner Losh         const U32 start = rankVal[weight];
18510c16b537SWarner Losh         U32 i = start;
18520c16b537SWarner Losh         const U32 end = start + length;
18530c16b537SWarner Losh 
18540c16b537SWarner Losh         MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
18550c16b537SWarner Losh         DElt.nbBits = (BYTE)(nbBits + consumed);
18560c16b537SWarner Losh         DElt.length = 2;
18570c16b537SWarner Losh         do { DTable[i++] = DElt; } while (i<end);   /* since length >= 1 */
18580c16b537SWarner Losh 
18590c16b537SWarner Losh         rankVal[weight] += length;
18600c16b537SWarner Losh     }
18610c16b537SWarner Losh }
18620c16b537SWarner Losh 
18630c16b537SWarner Losh typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
18640c16b537SWarner Losh 
18650c16b537SWarner Losh static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
18660c16b537SWarner Losh                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
18670c16b537SWarner Losh                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
18680c16b537SWarner Losh                            const U32 nbBitsBaseline)
18690c16b537SWarner Losh {
18700c16b537SWarner Losh     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
18710c16b537SWarner Losh     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
18720c16b537SWarner Losh     const U32 minBits  = nbBitsBaseline - maxWeight;
18730c16b537SWarner Losh     U32 s;
18740c16b537SWarner Losh 
18750c16b537SWarner Losh     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
18760c16b537SWarner Losh 
18770c16b537SWarner Losh     /* fill DTable */
18780c16b537SWarner Losh     for (s=0; s<sortedListSize; s++)
18790c16b537SWarner Losh     {
18800c16b537SWarner Losh         const U16 symbol = sortedList[s].symbol;
18810c16b537SWarner Losh         const U32 weight = sortedList[s].weight;
18820c16b537SWarner Losh         const U32 nbBits = nbBitsBaseline - weight;
18830c16b537SWarner Losh         const U32 start = rankVal[weight];
18840c16b537SWarner Losh         const U32 length = 1 << (targetLog-nbBits);
18850c16b537SWarner Losh 
18860c16b537SWarner Losh         if (targetLog-nbBits >= minBits)   /* enough room for a second symbol */
18870c16b537SWarner Losh         {
18880c16b537SWarner Losh             U32 sortedRank;
18890c16b537SWarner Losh             int minWeight = nbBits + scaleLog;
18900c16b537SWarner Losh             if (minWeight < 1) minWeight = 1;
18910c16b537SWarner Losh             sortedRank = rankStart[minWeight];
18920c16b537SWarner Losh             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
18930c16b537SWarner Losh                            rankValOrigin[nbBits], minWeight,
18940c16b537SWarner Losh                            sortedList+sortedRank, sortedListSize-sortedRank,
18950c16b537SWarner Losh                            nbBitsBaseline, symbol);
18960c16b537SWarner Losh         }
18970c16b537SWarner Losh         else
18980c16b537SWarner Losh         {
18990c16b537SWarner Losh             U32 i;
19000c16b537SWarner Losh             const U32 end = start + length;
19010c16b537SWarner Losh             HUF_DEltX4 DElt;
19020c16b537SWarner Losh 
19030c16b537SWarner Losh             MEM_writeLE16(&(DElt.sequence), symbol);
19040c16b537SWarner Losh             DElt.nbBits   = (BYTE)(nbBits);
19050c16b537SWarner Losh             DElt.length   = 1;
19060c16b537SWarner Losh             for (i = start; i < end; i++)
19070c16b537SWarner Losh                 DTable[i] = DElt;
19080c16b537SWarner Losh         }
19090c16b537SWarner Losh         rankVal[weight] += length;
19100c16b537SWarner Losh     }
19110c16b537SWarner Losh }
19120c16b537SWarner Losh 
19130c16b537SWarner Losh static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
19140c16b537SWarner Losh {
19150c16b537SWarner Losh     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
19160c16b537SWarner Losh     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
19170c16b537SWarner Losh     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
19180c16b537SWarner Losh     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
19190c16b537SWarner Losh     U32* const rankStart = rankStart0+1;
19200c16b537SWarner Losh     rankVal_t rankVal;
19210c16b537SWarner Losh     U32 tableLog, maxW, sizeOfSort, nbSymbols;
19220c16b537SWarner Losh     const U32 memLog = DTable[0];
19230c16b537SWarner Losh     const BYTE* ip = (const BYTE*) src;
19240c16b537SWarner Losh     size_t iSize = ip[0];
19250c16b537SWarner Losh     void* ptr = DTable;
19260c16b537SWarner Losh     HUF_DEltX4* const dt = ((HUF_DEltX4*)ptr) + 1;
19270c16b537SWarner Losh 
19280c16b537SWarner Losh     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
19290c16b537SWarner Losh     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
19300c16b537SWarner Losh     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
19310c16b537SWarner Losh 
19320c16b537SWarner Losh     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
19330c16b537SWarner Losh     if (HUF_isError(iSize)) return iSize;
19340c16b537SWarner Losh 
19350c16b537SWarner Losh     /* check result */
19360c16b537SWarner Losh     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
19370c16b537SWarner Losh 
19380c16b537SWarner Losh     /* find maxWeight */
19390c16b537SWarner Losh     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
19400c16b537SWarner Losh         { if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
19410c16b537SWarner Losh 
19420c16b537SWarner Losh     /* Get start index of each weight */
19430c16b537SWarner Losh     {
19440c16b537SWarner Losh         U32 w, nextRankStart = 0;
19450c16b537SWarner Losh         for (w=1; w<=maxW; w++)
19460c16b537SWarner Losh         {
19470c16b537SWarner Losh             U32 current = nextRankStart;
19480c16b537SWarner Losh             nextRankStart += rankStats[w];
19490c16b537SWarner Losh             rankStart[w] = current;
19500c16b537SWarner Losh         }
19510c16b537SWarner Losh         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
19520c16b537SWarner Losh         sizeOfSort = nextRankStart;
19530c16b537SWarner Losh     }
19540c16b537SWarner Losh 
19550c16b537SWarner Losh     /* sort symbols by weight */
19560c16b537SWarner Losh     {
19570c16b537SWarner Losh         U32 s;
19580c16b537SWarner Losh         for (s=0; s<nbSymbols; s++)
19590c16b537SWarner Losh         {
19600c16b537SWarner Losh             U32 w = weightList[s];
19610c16b537SWarner Losh             U32 r = rankStart[w]++;
19620c16b537SWarner Losh             sortedSymbol[r].symbol = (BYTE)s;
19630c16b537SWarner Losh             sortedSymbol[r].weight = (BYTE)w;
19640c16b537SWarner Losh         }
19650c16b537SWarner Losh         rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
19660c16b537SWarner Losh     }
19670c16b537SWarner Losh 
19680c16b537SWarner Losh     /* Build rankVal */
19690c16b537SWarner Losh     {
19700c16b537SWarner Losh         const U32 minBits = tableLog+1 - maxW;
19710c16b537SWarner Losh         U32 nextRankVal = 0;
19720c16b537SWarner Losh         U32 w, consumed;
19730c16b537SWarner Losh         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
19740c16b537SWarner Losh         U32* rankVal0 = rankVal[0];
19750c16b537SWarner Losh         for (w=1; w<=maxW; w++)
19760c16b537SWarner Losh         {
19770c16b537SWarner Losh             U32 current = nextRankVal;
19780c16b537SWarner Losh             nextRankVal += rankStats[w] << (w+rescale);
19790c16b537SWarner Losh             rankVal0[w] = current;
19800c16b537SWarner Losh         }
19810c16b537SWarner Losh         for (consumed = minBits; consumed <= memLog - minBits; consumed++)
19820c16b537SWarner Losh         {
19830c16b537SWarner Losh             U32* rankValPtr = rankVal[consumed];
19840c16b537SWarner Losh             for (w = 1; w <= maxW; w++)
19850c16b537SWarner Losh             {
19860c16b537SWarner Losh                 rankValPtr[w] = rankVal0[w] >> consumed;
19870c16b537SWarner Losh             }
19880c16b537SWarner Losh         }
19890c16b537SWarner Losh     }
19900c16b537SWarner Losh 
19910c16b537SWarner Losh     HUF_fillDTableX4(dt, memLog,
19920c16b537SWarner Losh                    sortedSymbol, sizeOfSort,
19930c16b537SWarner Losh                    rankStart0, rankVal, maxW,
19940c16b537SWarner Losh                    tableLog+1);
19950c16b537SWarner Losh 
19960c16b537SWarner Losh     return iSize;
19970c16b537SWarner Losh }
19980c16b537SWarner Losh 
19990c16b537SWarner Losh 
20000c16b537SWarner Losh static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
20010c16b537SWarner Losh {
20020c16b537SWarner Losh     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
20030c16b537SWarner Losh     memcpy(op, dt+val, 2);
20040c16b537SWarner Losh     BIT_skipBits(DStream, dt[val].nbBits);
20050c16b537SWarner Losh     return dt[val].length;
20060c16b537SWarner Losh }
20070c16b537SWarner Losh 
20080c16b537SWarner Losh static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
20090c16b537SWarner Losh {
20100c16b537SWarner Losh     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
20110c16b537SWarner Losh     memcpy(op, dt+val, 1);
20120c16b537SWarner Losh     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
20130c16b537SWarner Losh     else
20140c16b537SWarner Losh     {
20150c16b537SWarner Losh         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
20160c16b537SWarner Losh         {
20170c16b537SWarner Losh             BIT_skipBits(DStream, dt[val].nbBits);
20180c16b537SWarner Losh             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
20190c16b537SWarner Losh                 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 */
20200c16b537SWarner Losh         }
20210c16b537SWarner Losh     }
20220c16b537SWarner Losh     return 1;
20230c16b537SWarner Losh }
20240c16b537SWarner Losh 
20250c16b537SWarner Losh 
20260c16b537SWarner Losh #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
20270c16b537SWarner Losh     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
20280c16b537SWarner Losh 
20290c16b537SWarner Losh #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
20300c16b537SWarner Losh     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
20310c16b537SWarner Losh         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
20320c16b537SWarner Losh 
20330c16b537SWarner Losh #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
20340c16b537SWarner Losh     if (MEM_64bits()) \
20350c16b537SWarner Losh         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
20360c16b537SWarner Losh 
20370c16b537SWarner Losh static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
20380c16b537SWarner Losh {
20390c16b537SWarner Losh     BYTE* const pStart = p;
20400c16b537SWarner Losh 
20410c16b537SWarner Losh     /* up to 8 symbols at a time */
20420c16b537SWarner Losh     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
20430c16b537SWarner Losh     {
20440c16b537SWarner Losh         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
20450c16b537SWarner Losh         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
20460c16b537SWarner Losh         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
20470c16b537SWarner Losh         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
20480c16b537SWarner Losh     }
20490c16b537SWarner Losh 
20500c16b537SWarner Losh     /* closer to the end */
20510c16b537SWarner Losh     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
20520c16b537SWarner Losh         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
20530c16b537SWarner Losh 
20540c16b537SWarner Losh     while (p <= pEnd-2)
20550c16b537SWarner Losh         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
20560c16b537SWarner Losh 
20570c16b537SWarner Losh     if (p < pEnd)
20580c16b537SWarner Losh         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
20590c16b537SWarner Losh 
20600c16b537SWarner Losh     return p-pStart;
20610c16b537SWarner Losh }
20620c16b537SWarner Losh 
20630c16b537SWarner Losh 
20640c16b537SWarner Losh 
20650c16b537SWarner Losh static size_t HUF_decompress4X4_usingDTable(
20660c16b537SWarner Losh           void* dst,  size_t dstSize,
20670c16b537SWarner Losh     const void* cSrc, size_t cSrcSize,
20680c16b537SWarner Losh     const U32* DTable)
20690c16b537SWarner Losh {
20700c16b537SWarner Losh     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
20710c16b537SWarner Losh 
20720c16b537SWarner Losh     {
20730c16b537SWarner Losh         const BYTE* const istart = (const BYTE*) cSrc;
20740c16b537SWarner Losh         BYTE* const ostart = (BYTE*) dst;
20750c16b537SWarner Losh         BYTE* const oend = ostart + dstSize;
20760c16b537SWarner Losh 
20770c16b537SWarner Losh         const void* ptr = DTable;
20780c16b537SWarner Losh         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)ptr) +1;
20790c16b537SWarner Losh         const U32 dtLog = DTable[0];
20800c16b537SWarner Losh         size_t errorCode;
20810c16b537SWarner Losh 
20820c16b537SWarner Losh         /* Init */
20830c16b537SWarner Losh         BIT_DStream_t bitD1;
20840c16b537SWarner Losh         BIT_DStream_t bitD2;
20850c16b537SWarner Losh         BIT_DStream_t bitD3;
20860c16b537SWarner Losh         BIT_DStream_t bitD4;
20870c16b537SWarner Losh         const size_t length1 = MEM_readLE16(istart);
20880c16b537SWarner Losh         const size_t length2 = MEM_readLE16(istart+2);
20890c16b537SWarner Losh         const size_t length3 = MEM_readLE16(istart+4);
20900c16b537SWarner Losh         size_t length4;
20910c16b537SWarner Losh         const BYTE* const istart1 = istart + 6;  /* jumpTable */
20920c16b537SWarner Losh         const BYTE* const istart2 = istart1 + length1;
20930c16b537SWarner Losh         const BYTE* const istart3 = istart2 + length2;
20940c16b537SWarner Losh         const BYTE* const istart4 = istart3 + length3;
20950c16b537SWarner Losh         const size_t segmentSize = (dstSize+3) / 4;
20960c16b537SWarner Losh         BYTE* const opStart2 = ostart + segmentSize;
20970c16b537SWarner Losh         BYTE* const opStart3 = opStart2 + segmentSize;
20980c16b537SWarner Losh         BYTE* const opStart4 = opStart3 + segmentSize;
20990c16b537SWarner Losh         BYTE* op1 = ostart;
21000c16b537SWarner Losh         BYTE* op2 = opStart2;
21010c16b537SWarner Losh         BYTE* op3 = opStart3;
21020c16b537SWarner Losh         BYTE* op4 = opStart4;
21030c16b537SWarner Losh         U32 endSignal;
21040c16b537SWarner Losh 
21050c16b537SWarner Losh         length4 = cSrcSize - (length1 + length2 + length3 + 6);
21060c16b537SWarner Losh         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
21070c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD1, istart1, length1);
21080c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
21090c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD2, istart2, length2);
21100c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
21110c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD3, istart3, length3);
21120c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
21130c16b537SWarner Losh         errorCode = BIT_initDStream(&bitD4, istart4, length4);
21140c16b537SWarner Losh         if (HUF_isError(errorCode)) return errorCode;
21150c16b537SWarner Losh 
21160c16b537SWarner Losh         /* 16-32 symbols per loop (4-8 symbols per stream) */
21170c16b537SWarner Losh         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
21180c16b537SWarner Losh         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
21190c16b537SWarner Losh         {
21200c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
21210c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
21220c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
21230c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
21240c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
21250c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
21260c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
21270c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
21280c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
21290c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
21300c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
21310c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
21320c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
21330c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
21340c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
21350c16b537SWarner Losh             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
21360c16b537SWarner Losh 
21370c16b537SWarner Losh             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
21380c16b537SWarner Losh         }
21390c16b537SWarner Losh 
21400c16b537SWarner Losh         /* check corruption */
21410c16b537SWarner Losh         if (op1 > opStart2) return ERROR(corruption_detected);
21420c16b537SWarner Losh         if (op2 > opStart3) return ERROR(corruption_detected);
21430c16b537SWarner Losh         if (op3 > opStart4) return ERROR(corruption_detected);
21440c16b537SWarner Losh         /* note : op4 supposed already verified within main loop */
21450c16b537SWarner Losh 
21460c16b537SWarner Losh         /* finish bitStreams one by one */
21470c16b537SWarner Losh         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
21480c16b537SWarner Losh         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
21490c16b537SWarner Losh         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
21500c16b537SWarner Losh         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
21510c16b537SWarner Losh 
21520c16b537SWarner Losh         /* check */
21530c16b537SWarner Losh         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
21540c16b537SWarner Losh         if (!endSignal) return ERROR(corruption_detected);
21550c16b537SWarner Losh 
21560c16b537SWarner Losh         /* decoded size */
21570c16b537SWarner Losh         return dstSize;
21580c16b537SWarner Losh     }
21590c16b537SWarner Losh }
21600c16b537SWarner Losh 
21610c16b537SWarner Losh 
21620c16b537SWarner Losh static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
21630c16b537SWarner Losh {
21640c16b537SWarner Losh     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
21650c16b537SWarner Losh     const BYTE* ip = (const BYTE*) cSrc;
21660c16b537SWarner Losh 
21670c16b537SWarner Losh     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
21680c16b537SWarner Losh     if (HUF_isError(hSize)) return hSize;
21690c16b537SWarner Losh     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
21700c16b537SWarner Losh     ip += hSize;
21710c16b537SWarner Losh     cSrcSize -= hSize;
21720c16b537SWarner Losh 
21730c16b537SWarner Losh     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
21740c16b537SWarner Losh }
21750c16b537SWarner Losh 
21760c16b537SWarner Losh 
21770c16b537SWarner Losh /**********************************/
21780c16b537SWarner Losh /* Generic decompression selector */
21790c16b537SWarner Losh /**********************************/
21800c16b537SWarner Losh 
21810c16b537SWarner Losh typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
21820c16b537SWarner Losh static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
21830c16b537SWarner Losh {
21840c16b537SWarner Losh     /* single, double, quad */
21850c16b537SWarner Losh     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
21860c16b537SWarner Losh     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
21870c16b537SWarner Losh     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
21880c16b537SWarner Losh     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
21890c16b537SWarner Losh     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
21900c16b537SWarner Losh     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
21910c16b537SWarner Losh     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
21920c16b537SWarner Losh     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
21930c16b537SWarner Losh     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
21940c16b537SWarner Losh     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
21950c16b537SWarner Losh     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
21960c16b537SWarner Losh     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
21970c16b537SWarner Losh     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
21980c16b537SWarner Losh     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
21990c16b537SWarner Losh     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
22000c16b537SWarner Losh     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
22010c16b537SWarner Losh };
22020c16b537SWarner Losh 
22030c16b537SWarner Losh typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
22040c16b537SWarner Losh 
22050c16b537SWarner Losh static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
22060c16b537SWarner Losh {
22070c16b537SWarner Losh     static const decompressionAlgo decompress[3] = { HUF_decompress4X2, HUF_decompress4X4, NULL };
22080c16b537SWarner Losh     /* estimate decompression time */
22090c16b537SWarner Losh     U32 Q;
22100c16b537SWarner Losh     const U32 D256 = (U32)(dstSize >> 8);
22110c16b537SWarner Losh     U32 Dtime[3];
22120c16b537SWarner Losh     U32 algoNb = 0;
22130c16b537SWarner Losh     int n;
22140c16b537SWarner Losh 
22150c16b537SWarner Losh     /* validation checks */
22160c16b537SWarner Losh     if (dstSize == 0) return ERROR(dstSize_tooSmall);
22170c16b537SWarner Losh     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
22180c16b537SWarner Losh     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
22190c16b537SWarner Losh     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
22200c16b537SWarner Losh 
22210c16b537SWarner Losh     /* decoder timing evaluation */
22220c16b537SWarner Losh     Q = (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 since dstSize > cSrcSize */
22230c16b537SWarner Losh     for (n=0; n<3; n++)
22240c16b537SWarner Losh         Dtime[n] = algoTime[Q][n].tableTime + (algoTime[Q][n].decode256Time * D256);
22250c16b537SWarner Losh 
22260c16b537SWarner Losh     Dtime[1] += Dtime[1] >> 4; Dtime[2] += Dtime[2] >> 3; /* advantage to algorithms using less memory, for cache eviction */
22270c16b537SWarner Losh 
22280c16b537SWarner Losh     if (Dtime[1] < Dtime[0]) algoNb = 1;
22290c16b537SWarner Losh 
22300c16b537SWarner Losh     return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
22310c16b537SWarner Losh 
22320c16b537SWarner Losh     //return HUF_decompress4X2(dst, dstSize, cSrc, cSrcSize);   /* multi-streams single-symbol decoding */
22330c16b537SWarner Losh     //return HUF_decompress4X4(dst, dstSize, cSrc, cSrcSize);   /* multi-streams double-symbols decoding */
22340c16b537SWarner Losh     //return HUF_decompress4X6(dst, dstSize, cSrc, cSrcSize);   /* multi-streams quad-symbols decoding */
22350c16b537SWarner Losh }
22360c16b537SWarner Losh /*
22370c16b537SWarner Losh     zstd - standard compression library
22380c16b537SWarner Losh     Copyright (C) 2014-2015, Yann Collet.
22390c16b537SWarner Losh 
22400c16b537SWarner Losh     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
22410c16b537SWarner Losh 
22420c16b537SWarner Losh     Redistribution and use in source and binary forms, with or without
22430c16b537SWarner Losh     modification, are permitted provided that the following conditions are
22440c16b537SWarner Losh     met:
22450c16b537SWarner Losh     * Redistributions of source code must retain the above copyright
22460c16b537SWarner Losh     notice, this list of conditions and the following disclaimer.
22470c16b537SWarner Losh     * Redistributions in binary form must reproduce the above
22480c16b537SWarner Losh     copyright notice, this list of conditions and the following disclaimer
22490c16b537SWarner Losh     in the documentation and/or other materials provided with the
22500c16b537SWarner Losh     distribution.
22510c16b537SWarner Losh     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22520c16b537SWarner Losh     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22530c16b537SWarner Losh     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22540c16b537SWarner Losh     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22550c16b537SWarner Losh     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22560c16b537SWarner Losh     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22570c16b537SWarner Losh     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22580c16b537SWarner Losh     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22590c16b537SWarner Losh     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22600c16b537SWarner Losh     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
22610c16b537SWarner Losh     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22620c16b537SWarner Losh 
22630c16b537SWarner Losh     You can contact the author at :
22640c16b537SWarner Losh     - zstd source repository : https://github.com/Cyan4973/zstd
22650c16b537SWarner Losh     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
22660c16b537SWarner Losh */
22670c16b537SWarner Losh 
22680c16b537SWarner Losh /* ***************************************************************
22690c16b537SWarner Losh *  Tuning parameters
22700c16b537SWarner Losh *****************************************************************/
22710c16b537SWarner Losh /*!
22720c16b537SWarner Losh *  MEMORY_USAGE :
22730c16b537SWarner Losh *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
22740c16b537SWarner Losh *  Increasing memory usage improves compression ratio
22750c16b537SWarner Losh *  Reduced memory usage can improve speed, due to cache effect
22760c16b537SWarner Losh */
22770c16b537SWarner Losh #define ZSTD_MEMORY_USAGE 17
22780c16b537SWarner Losh 
22790c16b537SWarner Losh /*!
22800c16b537SWarner Losh  * HEAPMODE :
22810c16b537SWarner Losh  * Select how default compression functions will allocate memory for their hash table,
22820c16b537SWarner Losh  * in memory stack (0, fastest), or in memory heap (1, requires malloc())
22830c16b537SWarner Losh  * Note that compression context is fairly large, as a consequence heap memory is recommended.
22840c16b537SWarner Losh  */
22850c16b537SWarner Losh #ifndef ZSTD_HEAPMODE
22860c16b537SWarner Losh #  define ZSTD_HEAPMODE 1
22870c16b537SWarner Losh #endif /* ZSTD_HEAPMODE */
22880c16b537SWarner Losh 
22890c16b537SWarner Losh /*!
22900c16b537SWarner Losh *  LEGACY_SUPPORT :
22910c16b537SWarner Losh *  decompressor can decode older formats (starting from Zstd 0.1+)
22920c16b537SWarner Losh */
22930c16b537SWarner Losh #ifndef ZSTD_LEGACY_SUPPORT
22940c16b537SWarner Losh #  define ZSTD_LEGACY_SUPPORT 1
22950c16b537SWarner Losh #endif
22960c16b537SWarner Losh 
22970c16b537SWarner Losh 
22980c16b537SWarner Losh /* *******************************************************
22990c16b537SWarner Losh *  Includes
23000c16b537SWarner Losh *********************************************************/
23010c16b537SWarner Losh #include <stdlib.h>      /* calloc */
23020c16b537SWarner Losh #include <string.h>      /* memcpy, memmove */
23030c16b537SWarner Losh #include <stdio.h>       /* debug : printf */
23040c16b537SWarner Losh 
23050c16b537SWarner Losh 
23060c16b537SWarner Losh /* *******************************************************
23070c16b537SWarner Losh *  Compiler specifics
23080c16b537SWarner Losh *********************************************************/
23090c16b537SWarner Losh #ifdef __AVX2__
23100c16b537SWarner Losh #  include <immintrin.h>   /* AVX2 intrinsics */
23110c16b537SWarner Losh #endif
23120c16b537SWarner Losh 
23130c16b537SWarner Losh #ifdef _MSC_VER    /* Visual Studio */
23140c16b537SWarner Losh #  include <intrin.h>                    /* For Visual 2005 */
23150c16b537SWarner Losh #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
23160c16b537SWarner Losh #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
23170c16b537SWarner Losh #else
23180c16b537SWarner Losh #  define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
23190c16b537SWarner Losh #endif
23200c16b537SWarner Losh 
23210c16b537SWarner Losh 
23220c16b537SWarner Losh /* *******************************************************
23230c16b537SWarner Losh *  Constants
23240c16b537SWarner Losh *********************************************************/
23250c16b537SWarner Losh #define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
23260c16b537SWarner Losh #define HASH_TABLESIZE (1 << HASH_LOG)
23270c16b537SWarner Losh #define HASH_MASK (HASH_TABLESIZE - 1)
23280c16b537SWarner Losh 
23290c16b537SWarner Losh #define KNUTH 2654435761
23300c16b537SWarner Losh 
23310c16b537SWarner Losh #define BIT7 128
23320c16b537SWarner Losh #define BIT6  64
23330c16b537SWarner Losh #define BIT5  32
23340c16b537SWarner Losh #define BIT4  16
23350c16b537SWarner Losh #define BIT1   2
23360c16b537SWarner Losh #define BIT0   1
23370c16b537SWarner Losh 
23380c16b537SWarner Losh #define KB *(1 <<10)
23390c16b537SWarner Losh #define MB *(1 <<20)
23400c16b537SWarner Losh #define GB *(1U<<30)
23410c16b537SWarner Losh 
23420c16b537SWarner Losh #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
23430c16b537SWarner Losh #define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
23440c16b537SWarner Losh #define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
23450c16b537SWarner Losh #define IS_RAW BIT0
23460c16b537SWarner Losh #define IS_RLE BIT1
23470c16b537SWarner Losh 
23480c16b537SWarner Losh #define WORKPLACESIZE (BLOCKSIZE*3)
23490c16b537SWarner Losh #define MINMATCH 4
23500c16b537SWarner Losh #define MLbits   7
23510c16b537SWarner Losh #define LLbits   6
23520c16b537SWarner Losh #define Offbits  5
23530c16b537SWarner Losh #define MaxML  ((1<<MLbits )-1)
23540c16b537SWarner Losh #define MaxLL  ((1<<LLbits )-1)
23550c16b537SWarner Losh #define MaxOff   31
23560c16b537SWarner Losh #define LitFSELog  11
23570c16b537SWarner Losh #define MLFSELog   10
23580c16b537SWarner Losh #define LLFSELog   10
23590c16b537SWarner Losh #define OffFSELog   9
23600c16b537SWarner Losh #define MAX(a,b) ((a)<(b)?(b):(a))
23610c16b537SWarner Losh #define MaxSeq MAX(MaxLL, MaxML)
23620c16b537SWarner Losh 
23630c16b537SWarner Losh #define LITERAL_NOENTROPY 63
23640c16b537SWarner Losh #define COMMAND_NOENTROPY 7   /* to remove */
23650c16b537SWarner Losh 
23660c16b537SWarner Losh static const size_t ZSTD_blockHeaderSize = 3;
23670c16b537SWarner Losh static const size_t ZSTD_frameHeaderSize = 4;
23680c16b537SWarner Losh 
23690c16b537SWarner Losh 
23700c16b537SWarner Losh /* *******************************************************
23710c16b537SWarner Losh *  Memory operations
23720c16b537SWarner Losh **********************************************************/
23730c16b537SWarner Losh static void   ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
23740c16b537SWarner Losh 
23750c16b537SWarner Losh static void   ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
23760c16b537SWarner Losh 
23770c16b537SWarner Losh #define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }
23780c16b537SWarner Losh 
23790c16b537SWarner Losh /*! ZSTD_wildcopy : custom version of memcpy(), can copy up to 7-8 bytes too many */
23800c16b537SWarner Losh static void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length)
23810c16b537SWarner Losh {
23820c16b537SWarner Losh     const BYTE* ip = (const BYTE*)src;
23830c16b537SWarner Losh     BYTE* op = (BYTE*)dst;
23840c16b537SWarner Losh     BYTE* const oend = op + length;
23850c16b537SWarner Losh     do COPY8(op, ip) while (op < oend);
23860c16b537SWarner Losh }
23870c16b537SWarner Losh 
23880c16b537SWarner Losh 
23890c16b537SWarner Losh /* **************************************
23900c16b537SWarner Losh *  Local structures
23910c16b537SWarner Losh ****************************************/
23920c16b537SWarner Losh typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
23930c16b537SWarner Losh 
23940c16b537SWarner Losh typedef struct
23950c16b537SWarner Losh {
23960c16b537SWarner Losh     blockType_t blockType;
23970c16b537SWarner Losh     U32 origSize;
23980c16b537SWarner Losh } blockProperties_t;
23990c16b537SWarner Losh 
24000c16b537SWarner Losh typedef struct {
24010c16b537SWarner Losh     void* buffer;
24020c16b537SWarner Losh     U32*  offsetStart;
24030c16b537SWarner Losh     U32*  offset;
24040c16b537SWarner Losh     BYTE* offCodeStart;
24050c16b537SWarner Losh     BYTE* offCode;
24060c16b537SWarner Losh     BYTE* litStart;
24070c16b537SWarner Losh     BYTE* lit;
24080c16b537SWarner Losh     BYTE* litLengthStart;
24090c16b537SWarner Losh     BYTE* litLength;
24100c16b537SWarner Losh     BYTE* matchLengthStart;
24110c16b537SWarner Losh     BYTE* matchLength;
24120c16b537SWarner Losh     BYTE* dumpsStart;
24130c16b537SWarner Losh     BYTE* dumps;
24140c16b537SWarner Losh } seqStore_t;
24150c16b537SWarner Losh 
24160c16b537SWarner Losh 
24170c16b537SWarner Losh /* *************************************
24180c16b537SWarner Losh *  Error Management
24190c16b537SWarner Losh ***************************************/
24200c16b537SWarner Losh /*! ZSTD_isError
24210c16b537SWarner Losh *   tells if a return value is an error code */
24220c16b537SWarner Losh static unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
24230c16b537SWarner Losh 
24240c16b537SWarner Losh 
24250c16b537SWarner Losh 
24260c16b537SWarner Losh /* *************************************************************
24270c16b537SWarner Losh *   Decompression section
24280c16b537SWarner Losh ***************************************************************/
24290c16b537SWarner Losh struct ZSTD_DCtx_s
24300c16b537SWarner Losh {
24310c16b537SWarner Losh     U32 LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
24320c16b537SWarner Losh     U32 OffTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
24330c16b537SWarner Losh     U32 MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
24340c16b537SWarner Losh     void* previousDstEnd;
24350c16b537SWarner Losh     void* base;
24360c16b537SWarner Losh     size_t expected;
24370c16b537SWarner Losh     blockType_t bType;
24380c16b537SWarner Losh     U32 phase;
24390c16b537SWarner Losh     const BYTE* litPtr;
24400c16b537SWarner Losh     size_t litSize;
24410c16b537SWarner Losh     BYTE litBuffer[BLOCKSIZE + 8 /* margin for wildcopy */];
24420c16b537SWarner Losh };   /* typedef'd to ZSTD_Dctx within "zstd_static.h" */
24430c16b537SWarner Losh 
24440c16b537SWarner Losh 
24450c16b537SWarner Losh static size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
24460c16b537SWarner Losh {
24470c16b537SWarner Losh     const BYTE* const in = (const BYTE* const)src;
24480c16b537SWarner Losh     BYTE headerFlags;
24490c16b537SWarner Losh     U32 cSize;
24500c16b537SWarner Losh 
24510c16b537SWarner Losh     if (srcSize < 3) return ERROR(srcSize_wrong);
24520c16b537SWarner Losh 
24530c16b537SWarner Losh     headerFlags = *in;
24540c16b537SWarner Losh     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
24550c16b537SWarner Losh 
24560c16b537SWarner Losh     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
24570c16b537SWarner Losh     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
24580c16b537SWarner Losh 
24590c16b537SWarner Losh     if (bpPtr->blockType == bt_end) return 0;
24600c16b537SWarner Losh     if (bpPtr->blockType == bt_rle) return 1;
24610c16b537SWarner Losh     return cSize;
24620c16b537SWarner Losh }
24630c16b537SWarner Losh 
24640c16b537SWarner Losh static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
24650c16b537SWarner Losh {
24660c16b537SWarner Losh     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
24670c16b537SWarner Losh     memcpy(dst, src, srcSize);
24680c16b537SWarner Losh     return srcSize;
24690c16b537SWarner Losh }
24700c16b537SWarner Losh 
24710c16b537SWarner Losh 
24720c16b537SWarner Losh /** ZSTD_decompressLiterals
24730c16b537SWarner Losh     @return : nb of bytes read from src, or an error code*/
24740c16b537SWarner Losh static size_t ZSTD_decompressLiterals(void* dst, size_t* maxDstSizePtr,
24750c16b537SWarner Losh                                 const void* src, size_t srcSize)
24760c16b537SWarner Losh {
24770c16b537SWarner Losh     const BYTE* ip = (const BYTE*)src;
24780c16b537SWarner Losh 
24790c16b537SWarner Losh     const size_t litSize = (MEM_readLE32(src) & 0x1FFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
24800c16b537SWarner Losh     const size_t litCSize = (MEM_readLE32(ip+2) & 0xFFFFFF) >> 5;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
24810c16b537SWarner Losh 
24820c16b537SWarner Losh     if (litSize > *maxDstSizePtr) return ERROR(corruption_detected);
24830c16b537SWarner Losh     if (litCSize + 5 > srcSize) return ERROR(corruption_detected);
24840c16b537SWarner Losh 
24850c16b537SWarner Losh     if (HUF_isError(HUF_decompress(dst, litSize, ip+5, litCSize))) return ERROR(corruption_detected);
24860c16b537SWarner Losh 
24870c16b537SWarner Losh     *maxDstSizePtr = litSize;
24880c16b537SWarner Losh     return litCSize + 5;
24890c16b537SWarner Losh }
24900c16b537SWarner Losh 
24910c16b537SWarner Losh 
24920c16b537SWarner Losh /** ZSTD_decodeLiteralsBlock
24930c16b537SWarner Losh     @return : nb of bytes read from src (< srcSize )*/
24940c16b537SWarner Losh static size_t ZSTD_decodeLiteralsBlock(void* ctx,
24950c16b537SWarner Losh                           const void* src, size_t srcSize)
24960c16b537SWarner Losh {
24970c16b537SWarner Losh     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
24980c16b537SWarner Losh     const BYTE* const istart = (const BYTE* const)src;
24990c16b537SWarner Losh 
25000c16b537SWarner Losh     /* any compressed block with literals segment must be at least this size */
25010c16b537SWarner Losh     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
25020c16b537SWarner Losh 
25030c16b537SWarner Losh     switch(*istart & 3)
25040c16b537SWarner Losh     {
25050c16b537SWarner Losh     default:
25060c16b537SWarner Losh     case 0:
25070c16b537SWarner Losh         {
25080c16b537SWarner Losh             size_t litSize = BLOCKSIZE;
25090c16b537SWarner Losh             const size_t readSize = ZSTD_decompressLiterals(dctx->litBuffer, &litSize, src, srcSize);
25100c16b537SWarner Losh             dctx->litPtr = dctx->litBuffer;
25110c16b537SWarner Losh             dctx->litSize = litSize;
25120c16b537SWarner Losh             memset(dctx->litBuffer + dctx->litSize, 0, 8);
25130c16b537SWarner Losh             return readSize;   /* works if it's an error too */
25140c16b537SWarner Losh         }
25150c16b537SWarner Losh     case IS_RAW:
25160c16b537SWarner Losh         {
25170c16b537SWarner Losh             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
25180c16b537SWarner Losh             if (litSize > srcSize-11)   /* risk of reading too far with wildcopy */
25190c16b537SWarner Losh             {
25200c16b537SWarner Losh                 if (litSize > srcSize-3) return ERROR(corruption_detected);
25210c16b537SWarner Losh                 memcpy(dctx->litBuffer, istart, litSize);
25220c16b537SWarner Losh                 dctx->litPtr = dctx->litBuffer;
25230c16b537SWarner Losh                 dctx->litSize = litSize;
25240c16b537SWarner Losh                 memset(dctx->litBuffer + dctx->litSize, 0, 8);
25250c16b537SWarner Losh                 return litSize+3;
25260c16b537SWarner Losh             }
25270c16b537SWarner Losh             /* direct reference into compressed stream */
25280c16b537SWarner Losh             dctx->litPtr = istart+3;
25290c16b537SWarner Losh             dctx->litSize = litSize;
25300c16b537SWarner Losh             return litSize+3;
25310c16b537SWarner Losh         }
25320c16b537SWarner Losh     case IS_RLE:
25330c16b537SWarner Losh         {
25340c16b537SWarner Losh             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
25350c16b537SWarner Losh             if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
25360c16b537SWarner Losh             memset(dctx->litBuffer, istart[3], litSize + 8);
25370c16b537SWarner Losh             dctx->litPtr = dctx->litBuffer;
25380c16b537SWarner Losh             dctx->litSize = litSize;
25390c16b537SWarner Losh             return 4;
25400c16b537SWarner Losh         }
25410c16b537SWarner Losh     }
25420c16b537SWarner Losh }
25430c16b537SWarner Losh 
25440c16b537SWarner Losh 
25450c16b537SWarner Losh static size_t ZSTD_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
25460c16b537SWarner Losh                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
25470c16b537SWarner Losh                          const void* src, size_t srcSize)
25480c16b537SWarner Losh {
25490c16b537SWarner Losh     const BYTE* const istart = (const BYTE* const)src;
25500c16b537SWarner Losh     const BYTE* ip = istart;
25510c16b537SWarner Losh     const BYTE* const iend = istart + srcSize;
25520c16b537SWarner Losh     U32 LLtype, Offtype, MLtype;
25530c16b537SWarner Losh     U32 LLlog, Offlog, MLlog;
25540c16b537SWarner Losh     size_t dumpsLength;
25550c16b537SWarner Losh 
25560c16b537SWarner Losh     /* check */
25570c16b537SWarner Losh     if (srcSize < 5) return ERROR(srcSize_wrong);
25580c16b537SWarner Losh 
25590c16b537SWarner Losh     /* SeqHead */
25600c16b537SWarner Losh     *nbSeq = MEM_readLE16(ip); ip+=2;
25610c16b537SWarner Losh     LLtype  = *ip >> 6;
25620c16b537SWarner Losh     Offtype = (*ip >> 4) & 3;
25630c16b537SWarner Losh     MLtype  = (*ip >> 2) & 3;
25640c16b537SWarner Losh     if (*ip & 2)
25650c16b537SWarner Losh     {
25660c16b537SWarner Losh         dumpsLength  = ip[2];
25670c16b537SWarner Losh         dumpsLength += ip[1] << 8;
25680c16b537SWarner Losh         ip += 3;
25690c16b537SWarner Losh     }
25700c16b537SWarner Losh     else
25710c16b537SWarner Losh     {
25720c16b537SWarner Losh         dumpsLength  = ip[1];
25730c16b537SWarner Losh         dumpsLength += (ip[0] & 1) << 8;
25740c16b537SWarner Losh         ip += 2;
25750c16b537SWarner Losh     }
25760c16b537SWarner Losh     *dumpsPtr = ip;
25770c16b537SWarner Losh     ip += dumpsLength;
25780c16b537SWarner Losh     *dumpsLengthPtr = dumpsLength;
25790c16b537SWarner Losh 
25800c16b537SWarner Losh     /* check */
25810c16b537SWarner Losh     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
25820c16b537SWarner Losh 
25830c16b537SWarner Losh     /* sequences */
25840c16b537SWarner Losh     {
25850c16b537SWarner Losh         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL and MaxOff */
25860c16b537SWarner Losh         size_t headerSize;
25870c16b537SWarner Losh 
25880c16b537SWarner Losh         /* Build DTables */
25890c16b537SWarner Losh         switch(LLtype)
25900c16b537SWarner Losh         {
25910c16b537SWarner Losh         case bt_rle :
25920c16b537SWarner Losh             LLlog = 0;
25930c16b537SWarner Losh             FSE_buildDTable_rle(DTableLL, *ip++); break;
25940c16b537SWarner Losh         case bt_raw :
25950c16b537SWarner Losh             LLlog = LLbits;
25960c16b537SWarner Losh             FSE_buildDTable_raw(DTableLL, LLbits); break;
25970c16b537SWarner Losh         default :
25980c16b537SWarner Losh             {   U32 max = MaxLL;
25990c16b537SWarner Losh                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
26000c16b537SWarner Losh                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
26010c16b537SWarner Losh                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
26020c16b537SWarner Losh                 ip += headerSize;
26030c16b537SWarner Losh                 FSE_buildDTable(DTableLL, norm, max, LLlog);
26040c16b537SWarner Losh         }   }
26050c16b537SWarner Losh 
26060c16b537SWarner Losh         switch(Offtype)
26070c16b537SWarner Losh         {
26080c16b537SWarner Losh         case bt_rle :
26090c16b537SWarner Losh             Offlog = 0;
26100c16b537SWarner Losh             if (ip > iend-2) return ERROR(srcSize_wrong);   /* min : "raw", hence no header, but at least xxLog bits */
26110c16b537SWarner Losh             FSE_buildDTable_rle(DTableOffb, *ip++ & MaxOff); /* if *ip > MaxOff, data is corrupted */
26120c16b537SWarner Losh             break;
26130c16b537SWarner Losh         case bt_raw :
26140c16b537SWarner Losh             Offlog = Offbits;
26150c16b537SWarner Losh             FSE_buildDTable_raw(DTableOffb, Offbits); break;
26160c16b537SWarner Losh         default :
26170c16b537SWarner Losh             {   U32 max = MaxOff;
26180c16b537SWarner Losh                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
26190c16b537SWarner Losh                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
26200c16b537SWarner Losh                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
26210c16b537SWarner Losh                 ip += headerSize;
26220c16b537SWarner Losh                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
26230c16b537SWarner Losh         }   }
26240c16b537SWarner Losh 
26250c16b537SWarner Losh         switch(MLtype)
26260c16b537SWarner Losh         {
26270c16b537SWarner Losh         case bt_rle :
26280c16b537SWarner Losh             MLlog = 0;
26290c16b537SWarner Losh             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
26300c16b537SWarner Losh             FSE_buildDTable_rle(DTableML, *ip++); break;
26310c16b537SWarner Losh         case bt_raw :
26320c16b537SWarner Losh             MLlog = MLbits;
26330c16b537SWarner Losh             FSE_buildDTable_raw(DTableML, MLbits); break;
26340c16b537SWarner Losh         default :
26350c16b537SWarner Losh             {   U32 max = MaxML;
26360c16b537SWarner Losh                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
26370c16b537SWarner Losh                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
26380c16b537SWarner Losh                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
26390c16b537SWarner Losh                 ip += headerSize;
26400c16b537SWarner Losh                 FSE_buildDTable(DTableML, norm, max, MLlog);
26410c16b537SWarner Losh     }   }   }
26420c16b537SWarner Losh 
26430c16b537SWarner Losh     return ip-istart;
26440c16b537SWarner Losh }
26450c16b537SWarner Losh 
26460c16b537SWarner Losh 
26470c16b537SWarner Losh typedef struct {
26480c16b537SWarner Losh     size_t litLength;
26490c16b537SWarner Losh     size_t offset;
26500c16b537SWarner Losh     size_t matchLength;
26510c16b537SWarner Losh } seq_t;
26520c16b537SWarner Losh 
26530c16b537SWarner Losh typedef struct {
26540c16b537SWarner Losh     BIT_DStream_t DStream;
26550c16b537SWarner Losh     FSE_DState_t stateLL;
26560c16b537SWarner Losh     FSE_DState_t stateOffb;
26570c16b537SWarner Losh     FSE_DState_t stateML;
26580c16b537SWarner Losh     size_t prevOffset;
26590c16b537SWarner Losh     const BYTE* dumps;
26600c16b537SWarner Losh     const BYTE* dumpsEnd;
26610c16b537SWarner Losh } seqState_t;
26620c16b537SWarner Losh 
26630c16b537SWarner Losh 
26640c16b537SWarner Losh static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
26650c16b537SWarner Losh {
26660c16b537SWarner Losh     size_t litLength;
26670c16b537SWarner Losh     size_t prevOffset;
26680c16b537SWarner Losh     size_t offset;
26690c16b537SWarner Losh     size_t matchLength;
26700c16b537SWarner Losh     const BYTE* dumps = seqState->dumps;
26710c16b537SWarner Losh     const BYTE* const de = seqState->dumpsEnd;
26720c16b537SWarner Losh 
26730c16b537SWarner Losh     /* Literal length */
26740c16b537SWarner Losh     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
26750c16b537SWarner Losh     prevOffset = litLength ? seq->offset : seqState->prevOffset;
26760c16b537SWarner Losh     seqState->prevOffset = seq->offset;
26770c16b537SWarner Losh     if (litLength == MaxLL)
26780c16b537SWarner Losh     {
26790c16b537SWarner Losh         U32 add = *dumps++;
26800c16b537SWarner Losh         if (add < 255) litLength += add;
26810c16b537SWarner Losh         else
26820c16b537SWarner Losh         {
26830c16b537SWarner Losh             litLength = MEM_readLE32(dumps) & 0xFFFFFF;  /* no pb : dumps is always followed by seq tables > 1 byte */
26840c16b537SWarner Losh             dumps += 3;
26850c16b537SWarner Losh         }
26860c16b537SWarner Losh         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
26870c16b537SWarner Losh     }
26880c16b537SWarner Losh 
26890c16b537SWarner Losh     /* Offset */
26900c16b537SWarner Losh     {
26910c16b537SWarner Losh         static const size_t offsetPrefix[MaxOff+1] = {  /* note : size_t faster than U32 */
26920c16b537SWarner Losh                 1 /*fake*/, 1, 2, 4, 8, 16, 32, 64, 128, 256,
26930c16b537SWarner Losh                 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144,
26940c16b537SWarner Losh                 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, /*fake*/ 1, 1, 1, 1, 1 };
26950c16b537SWarner Losh         U32 offsetCode, nbBits;
26960c16b537SWarner Losh         offsetCode = FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream));   /* <= maxOff, by table construction */
26970c16b537SWarner Losh         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
26980c16b537SWarner Losh         nbBits = offsetCode - 1;
26990c16b537SWarner Losh         if (offsetCode==0) nbBits = 0;   /* cmove */
27000c16b537SWarner Losh         offset = offsetPrefix[offsetCode] + BIT_readBits(&(seqState->DStream), nbBits);
27010c16b537SWarner Losh         if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
27020c16b537SWarner Losh         if (offsetCode==0) offset = prevOffset;   /* cmove */
27030c16b537SWarner Losh     }
27040c16b537SWarner Losh 
27050c16b537SWarner Losh     /* MatchLength */
27060c16b537SWarner Losh     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
27070c16b537SWarner Losh     if (matchLength == MaxML)
27080c16b537SWarner Losh     {
27090c16b537SWarner Losh         U32 add = *dumps++;
27100c16b537SWarner Losh         if (add < 255) matchLength += add;
27110c16b537SWarner Losh         else
27120c16b537SWarner Losh         {
27130c16b537SWarner Losh             matchLength = MEM_readLE32(dumps) & 0xFFFFFF;  /* no pb : dumps is always followed by seq tables > 1 byte */
27140c16b537SWarner Losh             dumps += 3;
27150c16b537SWarner Losh         }
27160c16b537SWarner Losh         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
27170c16b537SWarner Losh     }
27180c16b537SWarner Losh     matchLength += MINMATCH;
27190c16b537SWarner Losh 
27200c16b537SWarner Losh     /* save result */
27210c16b537SWarner Losh     seq->litLength = litLength;
27220c16b537SWarner Losh     seq->offset = offset;
27230c16b537SWarner Losh     seq->matchLength = matchLength;
27240c16b537SWarner Losh     seqState->dumps = dumps;
27250c16b537SWarner Losh }
27260c16b537SWarner Losh 
27270c16b537SWarner Losh 
27280c16b537SWarner Losh static size_t ZSTD_execSequence(BYTE* op,
27290c16b537SWarner Losh                                 seq_t sequence,
27300c16b537SWarner Losh                                 const BYTE** litPtr, const BYTE* const litLimit,
27310c16b537SWarner Losh                                 BYTE* const base, BYTE* const oend)
27320c16b537SWarner Losh {
27330c16b537SWarner Losh     static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
27340c16b537SWarner Losh     static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11};   /* substracted */
27350c16b537SWarner Losh     const BYTE* const ostart = op;
27360c16b537SWarner Losh     BYTE* const oLitEnd = op + sequence.litLength;
27370c16b537SWarner Losh     BYTE* const oMatchEnd = op + sequence.litLength + sequence.matchLength;   /* risk : address space overflow (32-bits) */
27380c16b537SWarner Losh     BYTE* const oend_8 = oend-8;
27390c16b537SWarner Losh     const BYTE* const litEnd = *litPtr + sequence.litLength;
27400c16b537SWarner Losh 
27410c16b537SWarner Losh     /* checks */
27420c16b537SWarner Losh     if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall);   /* last match must start at a minimum distance of 8 from oend */
27430c16b537SWarner Losh     if (oMatchEnd > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
27440c16b537SWarner Losh     if (litEnd > litLimit) return ERROR(corruption_detected);   /* overRead beyond lit buffer */
27450c16b537SWarner Losh 
27460c16b537SWarner Losh     /* copy Literals */
27470c16b537SWarner Losh     ZSTD_wildcopy(op, *litPtr, sequence.litLength);   /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
27480c16b537SWarner Losh     op = oLitEnd;
27490c16b537SWarner Losh     *litPtr = litEnd;   /* update for next sequence */
27500c16b537SWarner Losh 
27510c16b537SWarner Losh     /* copy Match */
27520c16b537SWarner Losh     {
27530c16b537SWarner Losh         const BYTE* match = op - sequence.offset;
27540c16b537SWarner Losh 
27550c16b537SWarner Losh         /* check */
27560c16b537SWarner Losh         if (sequence.offset > (size_t)op) return ERROR(corruption_detected);   /* address space overflow test (this test seems kept by clang optimizer) */
27570c16b537SWarner Losh         //if (match > op) return ERROR(corruption_detected);   /* address space overflow test (is clang optimizer removing this test ?) */
27580c16b537SWarner Losh         if (match < base) return ERROR(corruption_detected);
27590c16b537SWarner Losh 
27600c16b537SWarner Losh         /* close range match, overlap */
27610c16b537SWarner Losh         if (sequence.offset < 8)
27620c16b537SWarner Losh         {
27630c16b537SWarner Losh             const int dec64 = dec64table[sequence.offset];
27640c16b537SWarner Losh             op[0] = match[0];
27650c16b537SWarner Losh             op[1] = match[1];
27660c16b537SWarner Losh             op[2] = match[2];
27670c16b537SWarner Losh             op[3] = match[3];
27680c16b537SWarner Losh             match += dec32table[sequence.offset];
27690c16b537SWarner Losh             ZSTD_copy4(op+4, match);
27700c16b537SWarner Losh             match -= dec64;
27710c16b537SWarner Losh         }
27720c16b537SWarner Losh         else
27730c16b537SWarner Losh         {
27740c16b537SWarner Losh             ZSTD_copy8(op, match);
27750c16b537SWarner Losh         }
27760c16b537SWarner Losh         op += 8; match += 8;
27770c16b537SWarner Losh 
27780c16b537SWarner Losh         if (oMatchEnd > oend-(16-MINMATCH))
27790c16b537SWarner Losh         {
27800c16b537SWarner Losh             if (op < oend_8)
27810c16b537SWarner Losh             {
27820c16b537SWarner Losh                 ZSTD_wildcopy(op, match, oend_8 - op);
27830c16b537SWarner Losh                 match += oend_8 - op;
27840c16b537SWarner Losh                 op = oend_8;
27850c16b537SWarner Losh             }
27860c16b537SWarner Losh             while (op < oMatchEnd) *op++ = *match++;
27870c16b537SWarner Losh         }
27880c16b537SWarner Losh         else
27890c16b537SWarner Losh         {
27900c16b537SWarner Losh             ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
27910c16b537SWarner Losh         }
27920c16b537SWarner Losh     }
27930c16b537SWarner Losh 
27940c16b537SWarner Losh     return oMatchEnd - ostart;
27950c16b537SWarner Losh }
27960c16b537SWarner Losh 
27970c16b537SWarner Losh static size_t ZSTD_decompressSequences(
27980c16b537SWarner Losh                                void* ctx,
27990c16b537SWarner Losh                                void* dst, size_t maxDstSize,
28000c16b537SWarner Losh                          const void* seqStart, size_t seqSize)
28010c16b537SWarner Losh {
28020c16b537SWarner Losh     ZSTD_DCtx* dctx = (ZSTD_DCtx*)ctx;
28030c16b537SWarner Losh     const BYTE* ip = (const BYTE*)seqStart;
28040c16b537SWarner Losh     const BYTE* const iend = ip + seqSize;
28050c16b537SWarner Losh     BYTE* const ostart = (BYTE* const)dst;
28060c16b537SWarner Losh     BYTE* op = ostart;
28070c16b537SWarner Losh     BYTE* const oend = ostart + maxDstSize;
28080c16b537SWarner Losh     size_t errorCode, dumpsLength;
28090c16b537SWarner Losh     const BYTE* litPtr = dctx->litPtr;
28100c16b537SWarner Losh     const BYTE* const litEnd = litPtr + dctx->litSize;
28110c16b537SWarner Losh     int nbSeq;
28120c16b537SWarner Losh     const BYTE* dumps;
28130c16b537SWarner Losh     U32* DTableLL = dctx->LLTable;
28140c16b537SWarner Losh     U32* DTableML = dctx->MLTable;
28150c16b537SWarner Losh     U32* DTableOffb = dctx->OffTable;
28160c16b537SWarner Losh     BYTE* const base = (BYTE*) (dctx->base);
28170c16b537SWarner Losh 
28180c16b537SWarner Losh     /* Build Decoding Tables */
28190c16b537SWarner Losh     errorCode = ZSTD_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
28200c16b537SWarner Losh                                       DTableLL, DTableML, DTableOffb,
28210c16b537SWarner Losh                                       ip, iend-ip);
28220c16b537SWarner Losh     if (ZSTD_isError(errorCode)) return errorCode;
28230c16b537SWarner Losh     ip += errorCode;
28240c16b537SWarner Losh 
28250c16b537SWarner Losh     /* Regen sequences */
28260c16b537SWarner Losh     {
28270c16b537SWarner Losh         seq_t sequence;
28280c16b537SWarner Losh         seqState_t seqState;
28290c16b537SWarner Losh 
28300c16b537SWarner Losh         memset(&sequence, 0, sizeof(sequence));
28310c16b537SWarner Losh         seqState.dumps = dumps;
28320c16b537SWarner Losh         seqState.dumpsEnd = dumps + dumpsLength;
28330c16b537SWarner Losh         seqState.prevOffset = sequence.offset = 4;
28340c16b537SWarner Losh         errorCode = BIT_initDStream(&(seqState.DStream), ip, iend-ip);
28350c16b537SWarner Losh         if (ERR_isError(errorCode)) return ERROR(corruption_detected);
28360c16b537SWarner Losh         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
28370c16b537SWarner Losh         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
28380c16b537SWarner Losh         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
28390c16b537SWarner Losh 
28400c16b537SWarner Losh         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (nbSeq>0) ; )
28410c16b537SWarner Losh         {
28420c16b537SWarner Losh             size_t oneSeqSize;
28430c16b537SWarner Losh             nbSeq--;
28440c16b537SWarner Losh             ZSTD_decodeSequence(&sequence, &seqState);
28450c16b537SWarner Losh             oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend);
28460c16b537SWarner Losh             if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
28470c16b537SWarner Losh             op += oneSeqSize;
28480c16b537SWarner Losh         }
28490c16b537SWarner Losh 
28500c16b537SWarner Losh         /* check if reached exact end */
28510c16b537SWarner Losh         if ( !BIT_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* requested too much : data is corrupted */
28520c16b537SWarner Losh         if (nbSeq<0) return ERROR(corruption_detected);   /* requested too many sequences : data is corrupted */
28530c16b537SWarner Losh 
28540c16b537SWarner Losh         /* last literal segment */
28550c16b537SWarner Losh         {
28560c16b537SWarner Losh             size_t lastLLSize = litEnd - litPtr;
28570c16b537SWarner Losh             if (litPtr > litEnd) return ERROR(corruption_detected);
28580c16b537SWarner Losh             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
28590c16b537SWarner Losh             if (op != litPtr) memmove(op, litPtr, lastLLSize);
28600c16b537SWarner Losh             op += lastLLSize;
28610c16b537SWarner Losh         }
28620c16b537SWarner Losh     }
28630c16b537SWarner Losh 
28640c16b537SWarner Losh     return op-ostart;
28650c16b537SWarner Losh }
28660c16b537SWarner Losh 
28670c16b537SWarner Losh 
28680c16b537SWarner Losh static size_t ZSTD_decompressBlock(
28690c16b537SWarner Losh                             void* ctx,
28700c16b537SWarner Losh                             void* dst, size_t maxDstSize,
28710c16b537SWarner Losh                       const void* src, size_t srcSize)
28720c16b537SWarner Losh {
28730c16b537SWarner Losh     /* blockType == blockCompressed */
28740c16b537SWarner Losh     const BYTE* ip = (const BYTE*)src;
28750c16b537SWarner Losh 
28760c16b537SWarner Losh     /* Decode literals sub-block */
28770c16b537SWarner Losh     size_t litCSize = ZSTD_decodeLiteralsBlock(ctx, src, srcSize);
28780c16b537SWarner Losh     if (ZSTD_isError(litCSize)) return litCSize;
28790c16b537SWarner Losh     ip += litCSize;
28800c16b537SWarner Losh     srcSize -= litCSize;
28810c16b537SWarner Losh 
28820c16b537SWarner Losh     return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize);
28830c16b537SWarner Losh }
28840c16b537SWarner Losh 
28850c16b537SWarner Losh 
28860c16b537SWarner Losh static size_t ZSTD_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
28870c16b537SWarner Losh {
28880c16b537SWarner Losh     const BYTE* ip = (const BYTE*)src;
28890c16b537SWarner Losh     const BYTE* iend = ip + srcSize;
28900c16b537SWarner Losh     BYTE* const ostart = (BYTE* const)dst;
28910c16b537SWarner Losh     BYTE* op = ostart;
28920c16b537SWarner Losh     BYTE* const oend = ostart + maxDstSize;
28930c16b537SWarner Losh     size_t remainingSize = srcSize;
28940c16b537SWarner Losh     U32 magicNumber;
28950c16b537SWarner Losh     blockProperties_t blockProperties;
28960c16b537SWarner Losh 
28970c16b537SWarner Losh     /* Frame Header */
28980c16b537SWarner Losh     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
28990c16b537SWarner Losh     magicNumber = MEM_readLE32(src);
29000c16b537SWarner Losh     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
29010c16b537SWarner Losh     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
29020c16b537SWarner Losh 
29030c16b537SWarner Losh     /* Loop on each block */
29040c16b537SWarner Losh     while (1)
29050c16b537SWarner Losh     {
29060c16b537SWarner Losh         size_t decodedSize=0;
29070c16b537SWarner Losh         size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &blockProperties);
29080c16b537SWarner Losh         if (ZSTD_isError(cBlockSize)) return cBlockSize;
29090c16b537SWarner Losh 
29100c16b537SWarner Losh         ip += ZSTD_blockHeaderSize;
29110c16b537SWarner Losh         remainingSize -= ZSTD_blockHeaderSize;
29120c16b537SWarner Losh         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
29130c16b537SWarner Losh 
29140c16b537SWarner Losh         switch(blockProperties.blockType)
29150c16b537SWarner Losh         {
29160c16b537SWarner Losh         case bt_compressed:
29170c16b537SWarner Losh             decodedSize = ZSTD_decompressBlock(ctx, op, oend-op, ip, cBlockSize);
29180c16b537SWarner Losh             break;
29190c16b537SWarner Losh         case bt_raw :
29200c16b537SWarner Losh             decodedSize = ZSTD_copyUncompressedBlock(op, oend-op, ip, cBlockSize);
29210c16b537SWarner Losh             break;
29220c16b537SWarner Losh         case bt_rle :
29230c16b537SWarner Losh             return ERROR(GENERIC);   /* not yet supported */
29240c16b537SWarner Losh             break;
29250c16b537SWarner Losh         case bt_end :
29260c16b537SWarner Losh             /* end of frame */
29270c16b537SWarner Losh             if (remainingSize) return ERROR(srcSize_wrong);
29280c16b537SWarner Losh             break;
29290c16b537SWarner Losh         default:
29300c16b537SWarner Losh             return ERROR(GENERIC);   /* impossible */
29310c16b537SWarner Losh         }
29320c16b537SWarner Losh         if (cBlockSize == 0) break;   /* bt_end */
29330c16b537SWarner Losh 
29340c16b537SWarner Losh         if (ZSTD_isError(decodedSize)) return decodedSize;
29350c16b537SWarner Losh         op += decodedSize;
29360c16b537SWarner Losh         ip += cBlockSize;
29370c16b537SWarner Losh         remainingSize -= cBlockSize;
29380c16b537SWarner Losh     }
29390c16b537SWarner Losh 
29400c16b537SWarner Losh     return op-ostart;
29410c16b537SWarner Losh }
29420c16b537SWarner Losh 
29430c16b537SWarner Losh static size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
29440c16b537SWarner Losh {
29450c16b537SWarner Losh     ZSTD_DCtx ctx;
29460c16b537SWarner Losh     ctx.base = dst;
29470c16b537SWarner Losh     return ZSTD_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
29480c16b537SWarner Losh }
29490c16b537SWarner Losh 
29500c16b537SWarner Losh static size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize)
29510c16b537SWarner Losh {
29520c16b537SWarner Losh     const BYTE* ip = (const BYTE*)src;
29530c16b537SWarner Losh     size_t remainingSize = srcSize;
29540c16b537SWarner Losh     U32 magicNumber;
29550c16b537SWarner Losh     blockProperties_t blockProperties;
29560c16b537SWarner Losh 
29570c16b537SWarner Losh     /* Frame Header */
29580c16b537SWarner Losh     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
29590c16b537SWarner Losh     magicNumber = MEM_readLE32(src);
29600c16b537SWarner Losh     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
29610c16b537SWarner Losh     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
29620c16b537SWarner Losh 
29630c16b537SWarner Losh     /* Loop on each block */
29640c16b537SWarner Losh     while (1)
29650c16b537SWarner Losh     {
29660c16b537SWarner Losh         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
29670c16b537SWarner Losh         if (ZSTD_isError(cBlockSize)) return cBlockSize;
29680c16b537SWarner Losh 
29690c16b537SWarner Losh         ip += ZSTD_blockHeaderSize;
29700c16b537SWarner Losh         remainingSize -= ZSTD_blockHeaderSize;
29710c16b537SWarner Losh         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
29720c16b537SWarner Losh 
29730c16b537SWarner Losh         if (cBlockSize == 0) break;   /* bt_end */
29740c16b537SWarner Losh 
29750c16b537SWarner Losh         ip += cBlockSize;
29760c16b537SWarner Losh         remainingSize -= cBlockSize;
29770c16b537SWarner Losh     }
29780c16b537SWarner Losh 
29790c16b537SWarner Losh     return ip - (const BYTE*)src;
29800c16b537SWarner Losh }
29810c16b537SWarner Losh 
29820c16b537SWarner Losh 
29830c16b537SWarner Losh /*******************************
29840c16b537SWarner Losh *  Streaming Decompression API
29850c16b537SWarner Losh *******************************/
29860c16b537SWarner Losh 
29870c16b537SWarner Losh static size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx)
29880c16b537SWarner Losh {
29890c16b537SWarner Losh     dctx->expected = ZSTD_frameHeaderSize;
29900c16b537SWarner Losh     dctx->phase = 0;
29910c16b537SWarner Losh     dctx->previousDstEnd = NULL;
29920c16b537SWarner Losh     dctx->base = NULL;
29930c16b537SWarner Losh     return 0;
29940c16b537SWarner Losh }
29950c16b537SWarner Losh 
29960c16b537SWarner Losh static ZSTD_DCtx* ZSTD_createDCtx(void)
29970c16b537SWarner Losh {
29980c16b537SWarner Losh     ZSTD_DCtx* dctx = (ZSTD_DCtx*)malloc(sizeof(ZSTD_DCtx));
29990c16b537SWarner Losh     if (dctx==NULL) return NULL;
30000c16b537SWarner Losh     ZSTD_resetDCtx(dctx);
30010c16b537SWarner Losh     return dctx;
30020c16b537SWarner Losh }
30030c16b537SWarner Losh 
30040c16b537SWarner Losh static size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
30050c16b537SWarner Losh {
30060c16b537SWarner Losh     free(dctx);
30070c16b537SWarner Losh     return 0;
30080c16b537SWarner Losh }
30090c16b537SWarner Losh 
30100c16b537SWarner Losh static size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx)
30110c16b537SWarner Losh {
30120c16b537SWarner Losh     return dctx->expected;
30130c16b537SWarner Losh }
30140c16b537SWarner Losh 
30150c16b537SWarner Losh static size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
30160c16b537SWarner Losh {
30170c16b537SWarner Losh     /* Sanity check */
30180c16b537SWarner Losh     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
30190c16b537SWarner Losh     if (dst != ctx->previousDstEnd)  /* not contiguous */
30200c16b537SWarner Losh         ctx->base = dst;
30210c16b537SWarner Losh 
30220c16b537SWarner Losh     /* Decompress : frame header */
30230c16b537SWarner Losh     if (ctx->phase == 0)
30240c16b537SWarner Losh     {
30250c16b537SWarner Losh         /* Check frame magic header */
30260c16b537SWarner Losh         U32 magicNumber = MEM_readLE32(src);
30270c16b537SWarner Losh         if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
30280c16b537SWarner Losh         ctx->phase = 1;
30290c16b537SWarner Losh         ctx->expected = ZSTD_blockHeaderSize;
30300c16b537SWarner Losh         return 0;
30310c16b537SWarner Losh     }
30320c16b537SWarner Losh 
30330c16b537SWarner Losh     /* Decompress : block header */
30340c16b537SWarner Losh     if (ctx->phase == 1)
30350c16b537SWarner Losh     {
30360c16b537SWarner Losh         blockProperties_t bp;
30370c16b537SWarner Losh         size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
30380c16b537SWarner Losh         if (ZSTD_isError(blockSize)) return blockSize;
30390c16b537SWarner Losh         if (bp.blockType == bt_end)
30400c16b537SWarner Losh         {
30410c16b537SWarner Losh             ctx->expected = 0;
30420c16b537SWarner Losh             ctx->phase = 0;
30430c16b537SWarner Losh         }
30440c16b537SWarner Losh         else
30450c16b537SWarner Losh         {
30460c16b537SWarner Losh             ctx->expected = blockSize;
30470c16b537SWarner Losh             ctx->bType = bp.blockType;
30480c16b537SWarner Losh             ctx->phase = 2;
30490c16b537SWarner Losh         }
30500c16b537SWarner Losh 
30510c16b537SWarner Losh         return 0;
30520c16b537SWarner Losh     }
30530c16b537SWarner Losh 
30540c16b537SWarner Losh     /* Decompress : block content */
30550c16b537SWarner Losh     {
30560c16b537SWarner Losh         size_t rSize;
30570c16b537SWarner Losh         switch(ctx->bType)
30580c16b537SWarner Losh         {
30590c16b537SWarner Losh         case bt_compressed:
30600c16b537SWarner Losh             rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
30610c16b537SWarner Losh             break;
30620c16b537SWarner Losh         case bt_raw :
30630c16b537SWarner Losh             rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize);
30640c16b537SWarner Losh             break;
30650c16b537SWarner Losh         case bt_rle :
30660c16b537SWarner Losh             return ERROR(GENERIC);   /* not yet handled */
30670c16b537SWarner Losh             break;
30680c16b537SWarner Losh         case bt_end :   /* should never happen (filtered at phase 1) */
30690c16b537SWarner Losh             rSize = 0;
30700c16b537SWarner Losh             break;
30710c16b537SWarner Losh         default:
30720c16b537SWarner Losh             return ERROR(GENERIC);
30730c16b537SWarner Losh         }
30740c16b537SWarner Losh         ctx->phase = 1;
30750c16b537SWarner Losh         ctx->expected = ZSTD_blockHeaderSize;
30760c16b537SWarner Losh         ctx->previousDstEnd = (void*)( ((char*)dst) + rSize);
30770c16b537SWarner Losh         return rSize;
30780c16b537SWarner Losh     }
30790c16b537SWarner Losh 
30800c16b537SWarner Losh }
30810c16b537SWarner Losh 
30820c16b537SWarner Losh 
30830c16b537SWarner Losh /* wrapper layer */
30840c16b537SWarner Losh 
30850c16b537SWarner Losh unsigned ZSTDv03_isError(size_t code)
30860c16b537SWarner Losh {
30870c16b537SWarner Losh     return ZSTD_isError(code);
30880c16b537SWarner Losh }
30890c16b537SWarner Losh 
30900c16b537SWarner Losh size_t ZSTDv03_decompress( void* dst, size_t maxOriginalSize,
30910c16b537SWarner Losh                      const void* src, size_t compressedSize)
30920c16b537SWarner Losh {
30930c16b537SWarner Losh     return ZSTD_decompress(dst, maxOriginalSize, src, compressedSize);
30940c16b537SWarner Losh }
30950c16b537SWarner Losh 
30960c16b537SWarner Losh size_t ZSTDv03_findFrameCompressedSize(const void* src, size_t srcSize)
30970c16b537SWarner Losh {
30980c16b537SWarner Losh     return ZSTD_findFrameCompressedSize(src, srcSize);
30990c16b537SWarner Losh }
31000c16b537SWarner Losh 
31010c16b537SWarner Losh ZSTDv03_Dctx* ZSTDv03_createDCtx(void)
31020c16b537SWarner Losh {
31030c16b537SWarner Losh     return (ZSTDv03_Dctx*)ZSTD_createDCtx();
31040c16b537SWarner Losh }
31050c16b537SWarner Losh 
31060c16b537SWarner Losh size_t ZSTDv03_freeDCtx(ZSTDv03_Dctx* dctx)
31070c16b537SWarner Losh {
31080c16b537SWarner Losh     return ZSTD_freeDCtx((ZSTD_DCtx*)dctx);
31090c16b537SWarner Losh }
31100c16b537SWarner Losh 
31110c16b537SWarner Losh size_t ZSTDv03_resetDCtx(ZSTDv03_Dctx* dctx)
31120c16b537SWarner Losh {
31130c16b537SWarner Losh     return ZSTD_resetDCtx((ZSTD_DCtx*)dctx);
31140c16b537SWarner Losh }
31150c16b537SWarner Losh 
31160c16b537SWarner Losh size_t ZSTDv03_nextSrcSizeToDecompress(ZSTDv03_Dctx* dctx)
31170c16b537SWarner Losh {
31180c16b537SWarner Losh     return ZSTD_nextSrcSizeToDecompress((ZSTD_DCtx*)dctx);
31190c16b537SWarner Losh }
31200c16b537SWarner Losh 
31210c16b537SWarner Losh size_t ZSTDv03_decompressContinue(ZSTDv03_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
31220c16b537SWarner Losh {
31230c16b537SWarner Losh     return ZSTD_decompressContinue((ZSTD_DCtx*)dctx, dst, maxDstSize, src, srcSize);
31240c16b537SWarner Losh }
3125