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annotate contrib/python-zstandard/zstd/common/bitstream.h @ 37495:b1fb341d8a61

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zstandard: vendor python-zstandard 0.9.0 This was just released. It features a number of goodies. More info at https://gregoryszorc.com/blog/2018/04/09/release-of-python-zstandard-0.9/. The clang-format ignore list was updated to reflect the new source of files. The project contains a vendored copy of zstandard 1.3.4. The old version was 1.1.3. One of the changes between those versions is that zstandard is now dual licensed BSD + GPLv2 and the patent rights grant has been removed. Good riddance. The API should be backwards compatible. So no changes in core should be needed. However, there were a number of changes in the library that we'll want to adapt to. Those will be addressed in subsequent commits. Differential Revision: https://phab.mercurial-scm.org/D3198
author Gregory Szorc <gregory.szorc@gmail.com>
date Mon, 09 Apr 2018 10:13:29 -0700
parents b54a2984cdd4
children 73fef626dae3
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1 /* ******************************************************************
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2 bitstream
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3 Part of FSE library
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4 header file (to include)
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5 Copyright (C) 2013-2017, Yann Collet.
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6
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7 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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8
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9 Redistribution and use in source and binary forms, with or without
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10 modification, are permitted provided that the following conditions are
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11 met:
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12
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13 * Redistributions of source code must retain the above copyright
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14 notice, this list of conditions and the following disclaimer.
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15 * Redistributions in binary form must reproduce the above
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16 copyright notice, this list of conditions and the following disclaimer
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17 in the documentation and/or other materials provided with the
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18 distribution.
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19
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20 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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21 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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22 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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23 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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24 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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25 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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26 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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27 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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28 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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29 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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30 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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31
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32 You can contact the author at :
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33 - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
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34 ****************************************************************** */
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35 #ifndef BITSTREAM_H_MODULE
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36 #define BITSTREAM_H_MODULE
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37
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38 #if defined (__cplusplus)
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39 extern "C" {
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40 #endif
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41
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42 /*
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43 * This API consists of small unitary functions, which must be inlined for best performance.
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44 * Since link-time-optimization is not available for all compilers,
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45 * these functions are defined into a .h to be included.
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46 */
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47
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48 /*-****************************************
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49 * Dependencies
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50 ******************************************/
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51 #include "mem.h" /* unaligned access routines */
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52 #include "error_private.h" /* error codes and messages */
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53
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54
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55 /*-*************************************
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56 * Debug
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57 ***************************************/
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58 #if defined(BIT_DEBUG) && (BIT_DEBUG>=1)
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59 # include <assert.h>
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60 #else
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61 # ifndef assert
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62 # define assert(condition) ((void)0)
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63 # endif
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64 #endif
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65
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66
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67 /*=========================================
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68 * Target specific
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69 =========================================*/
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70 #if defined(__BMI__) && defined(__GNUC__)
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71 # include <immintrin.h> /* support for bextr (experimental) */
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72 #endif
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73
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74 #define STREAM_ACCUMULATOR_MIN_32 25
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75 #define STREAM_ACCUMULATOR_MIN_64 57
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76 #define STREAM_ACCUMULATOR_MIN ((U32)(MEM_32bits() ? STREAM_ACCUMULATOR_MIN_32 : STREAM_ACCUMULATOR_MIN_64))
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77
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78
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79 /*-******************************************
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80 * bitStream encoding API (write forward)
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81 ********************************************/
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82 /* bitStream can mix input from multiple sources.
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83 * A critical property of these streams is that they encode and decode in **reverse** direction.
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84 * So the first bit sequence you add will be the last to be read, like a LIFO stack.
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85 */
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86 typedef struct
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87 {
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88 size_t bitContainer;
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89 unsigned bitPos;
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90 char* startPtr;
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91 char* ptr;
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92 char* endPtr;
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93 } BIT_CStream_t;
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94
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95 MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC, void* dstBuffer, size_t dstCapacity);
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96 MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
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97 MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC);
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98 MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC);
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99
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100 /* Start with initCStream, providing the size of buffer to write into.
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101 * bitStream will never write outside of this buffer.
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102 * `dstCapacity` must be >= sizeof(bitD->bitContainer), otherwise @return will be an error code.
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103 *
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104 * bits are first added to a local register.
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105 * Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
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106 * Writing data into memory is an explicit operation, performed by the flushBits function.
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107 * Hence keep track how many bits are potentially stored into local register to avoid register overflow.
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108 * After a flushBits, a maximum of 7 bits might still be stored into local register.
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109 *
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110 * Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
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111 *
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112 * Last operation is to close the bitStream.
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113 * The function returns the final size of CStream in bytes.
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114 * If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
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115 */
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116
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117
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118 /*-********************************************
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119 * bitStream decoding API (read backward)
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120 **********************************************/
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121 typedef struct
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122 {
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123 size_t bitContainer;
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124 unsigned bitsConsumed;
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125 const char* ptr;
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126 const char* start;
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127 const char* limitPtr;
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128 } BIT_DStream_t;
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129
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diff changeset
130 typedef enum { BIT_DStream_unfinished = 0,
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
131 BIT_DStream_endOfBuffer = 1,
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
132 BIT_DStream_completed = 2,
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
133 BIT_DStream_overflow = 3 } BIT_DStream_status; /* result of BIT_reloadDStream() */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
134 /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
135
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
136 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
137 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
138 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
139 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
140
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
141
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
142 /* Start by invoking BIT_initDStream().
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
143 * A chunk of the bitStream is then stored into a local register.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
144 * Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
145 * You can then retrieve bitFields stored into the local register, **in reverse order**.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
146 * Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
147 * A reload guarantee a minimum of ((8*sizeof(bitD->bitContainer))-7) bits when its result is BIT_DStream_unfinished.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
148 * Otherwise, it can be less than that, so proceed accordingly.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
149 * Checking if DStream has reached its end can be performed with BIT_endOfDStream().
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
150 */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
151
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
152
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
153 /*-****************************************
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
154 * unsafe API
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
155 ******************************************/
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
156 MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
157 /* faster, but works only if value is "clean", meaning all high bits above nbBits are 0 */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
158
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
159 MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
160 /* unsafe version; does not check buffer overflow */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
161
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
162 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
163 /* faster, but works only if nbBits >= 1 */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
164
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
165
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
166
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
167 /*-**************************************************************
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
168 * Internal functions
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
169 ****************************************************************/
37495
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Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
170 MEM_STATIC unsigned BIT_highbit32 (U32 val)
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
171 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
172 assert(val != 0);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
173 {
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
174 # if defined(_MSC_VER) /* Visual */
37495
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Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
175 unsigned long r=0;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
176 _BitScanReverse ( &r, val );
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
177 return (unsigned) r;
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
178 # elif defined(__GNUC__) && (__GNUC__ >= 3) /* Use GCC Intrinsic */
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
179 return 31 - __builtin_clz (val);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
180 # else /* Software version */
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
181 static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
182 11, 14, 16, 18, 22, 25, 3, 30,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
183 8, 12, 20, 28, 15, 17, 24, 7,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
184 19, 27, 23, 6, 26, 5, 4, 31 };
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
185 U32 v = val;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
186 v |= v >> 1;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
187 v |= v >> 2;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
188 v |= v >> 4;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
189 v |= v >> 8;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
190 v |= v >> 16;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
191 return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
192 # endif
37495
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Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
193 }
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
194 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
195
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
196 /*===== Local Constants =====*/
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
197 static const unsigned BIT_mask[] = {
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
198 0, 1, 3, 7, 0xF, 0x1F,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
199 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
200 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0x1FFFF,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
201 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF, 0x7FFFFF,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
202 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF, 0xFFFFFFF, 0x1FFFFFFF,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
203 0x3FFFFFFF, 0x7FFFFFFF}; /* up to 31 bits */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
204 #define BIT_MASK_SIZE (sizeof(BIT_mask) / sizeof(BIT_mask[0]))
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
205
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
206 /*-**************************************************************
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
207 * bitStream encoding
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
208 ****************************************************************/
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
209 /*! BIT_initCStream() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
210 * `dstCapacity` must be > sizeof(size_t)
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
211 * @return : 0 if success,
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
212 * otherwise an error code (can be tested using ERR_isError()) */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
213 MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
214 void* startPtr, size_t dstCapacity)
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
215 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
216 bitC->bitContainer = 0;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
217 bitC->bitPos = 0;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
218 bitC->startPtr = (char*)startPtr;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
219 bitC->ptr = bitC->startPtr;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
220 bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->bitContainer);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
221 if (dstCapacity <= sizeof(bitC->bitContainer)) return ERROR(dstSize_tooSmall);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
222 return 0;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
223 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
224
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
225 /*! BIT_addBits() :
37495
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Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
226 * can add up to 31 bits into `bitC`.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
227 * Note : does not check for register overflow ! */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
228 MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
229 size_t value, unsigned nbBits)
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
230 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
231 MEM_STATIC_ASSERT(BIT_MASK_SIZE == 32);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
232 assert(nbBits < BIT_MASK_SIZE);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
233 assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
234 bitC->bitContainer |= (value & BIT_mask[nbBits]) << bitC->bitPos;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
235 bitC->bitPos += nbBits;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
236 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
237
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
238 /*! BIT_addBitsFast() :
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
239 * works only if `value` is _clean_, meaning all high bits above nbBits are 0 */
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
240 MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC,
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
241 size_t value, unsigned nbBits)
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
242 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
243 assert((value>>nbBits) == 0);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
244 assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
245 bitC->bitContainer |= value << bitC->bitPos;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
246 bitC->bitPos += nbBits;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
247 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
248
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
249 /*! BIT_flushBitsFast() :
37495
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Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
250 * assumption : bitContainer has not overflowed
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
251 * unsafe version; does not check buffer overflow */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
252 MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
253 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
254 size_t const nbBytes = bitC->bitPos >> 3;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
255 assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
256 MEM_writeLEST(bitC->ptr, bitC->bitContainer);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
257 bitC->ptr += nbBytes;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
258 assert(bitC->ptr <= bitC->endPtr);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
259 bitC->bitPos &= 7;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
260 bitC->bitContainer >>= nbBytes*8;
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
261 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
262
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
263 /*! BIT_flushBits() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
264 * assumption : bitContainer has not overflowed
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
265 * safe version; check for buffer overflow, and prevents it.
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
266 * note : does not signal buffer overflow.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
267 * overflow will be revealed later on using BIT_closeCStream() */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
268 MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
269 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
270 size_t const nbBytes = bitC->bitPos >> 3;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
271 assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
272 MEM_writeLEST(bitC->ptr, bitC->bitContainer);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
273 bitC->ptr += nbBytes;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
274 if (bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
275 bitC->bitPos &= 7;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
276 bitC->bitContainer >>= nbBytes*8;
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
277 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
278
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
279 /*! BIT_closeCStream() :
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
280 * @return : size of CStream, in bytes,
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
281 * or 0 if it could not fit into dstBuffer */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
282 MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
283 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
284 BIT_addBitsFast(bitC, 1, 1); /* endMark */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
285 BIT_flushBits(bitC);
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
286 if (bitC->ptr >= bitC->endPtr) return 0; /* overflow detected */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
287 return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
288 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
289
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
290
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
291 /*-********************************************************
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
292 * bitStream decoding
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
293 **********************************************************/
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
294 /*! BIT_initDStream() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
295 * Initialize a BIT_DStream_t.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
296 * `bitD` : a pointer to an already allocated BIT_DStream_t structure.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
297 * `srcSize` must be the *exact* size of the bitStream, in bytes.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
298 * @return : size of stream (== srcSize), or an errorCode if a problem is detected
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
299 */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
300 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
301 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
302 if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
303
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
304 bitD->start = (const char*)srcBuffer;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
305 bitD->limitPtr = bitD->start + sizeof(bitD->bitContainer);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
306
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
307 if (srcSize >= sizeof(bitD->bitContainer)) { /* normal case */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
308 bitD->ptr = (const char*)srcBuffer + srcSize - sizeof(bitD->bitContainer);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
309 bitD->bitContainer = MEM_readLEST(bitD->ptr);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
310 { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
30822
b54a2984cdd4 zstd: vendor python-zstandard 0.6.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30434
diff changeset
311 bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0; /* ensures bitsConsumed is always set */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
312 if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
313 } else {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
314 bitD->ptr = bitD->start;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
315 bitD->bitContainer = *(const BYTE*)(bitD->start);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
316 switch(srcSize)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
317 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
318 case 7: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
319 /* fall-through */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
320
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
321 case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
322 /* fall-through */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
323
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
324 case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
325 /* fall-through */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
326
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
327 case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
328 /* fall-through */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
329
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
330 case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
331 /* fall-through */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
332
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
333 case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) << 8;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
334 /* fall-through */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
335
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
336 default: break;
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
337 }
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
338 { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
339 bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
340 if (lastByte == 0) return ERROR(corruption_detected); /* endMark not present */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
341 }
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
342 bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize)*8;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
343 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
344
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
345 return srcSize;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
346 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
347
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
348 MEM_STATIC size_t BIT_getUpperBits(size_t bitContainer, U32 const start)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
349 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
350 return bitContainer >> start;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
351 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
352
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
353 MEM_STATIC size_t BIT_getMiddleBits(size_t bitContainer, U32 const start, U32 const nbBits)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
354 {
30822
b54a2984cdd4 zstd: vendor python-zstandard 0.6.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30434
diff changeset
355 #if defined(__BMI__) && defined(__GNUC__) && __GNUC__*1000+__GNUC_MINOR__ >= 4008 /* experimental */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
356 # if defined(__x86_64__)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
357 if (sizeof(bitContainer)==8)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
358 return _bextr_u64(bitContainer, start, nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
359 else
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
360 # endif
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
361 return _bextr_u32(bitContainer, start, nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
362 #else
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
363 assert(nbBits < BIT_MASK_SIZE);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
364 return (bitContainer >> start) & BIT_mask[nbBits];
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
365 #endif
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
366 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
367
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
368 MEM_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
369 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
370 assert(nbBits < BIT_MASK_SIZE);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
371 return bitContainer & BIT_mask[nbBits];
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
372 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
373
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
374 /*! BIT_lookBits() :
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
375 * Provides next n bits from local register.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
376 * local register is not modified.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
377 * On 32-bits, maxNbBits==24.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
378 * On 64-bits, maxNbBits==56.
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
379 * @return : value extracted */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
380 MEM_STATIC size_t BIT_lookBits(const BIT_DStream_t* bitD, U32 nbBits)
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
381 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
382 #if defined(__BMI__) && defined(__GNUC__) /* experimental; fails if bitD->bitsConsumed + nbBits > sizeof(bitD->bitContainer)*8 */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
383 return BIT_getMiddleBits(bitD->bitContainer, (sizeof(bitD->bitContainer)*8) - bitD->bitsConsumed - nbBits, nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
384 #else
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
385 U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
386 return ((bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> 1) >> ((regMask-nbBits) & regMask);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
387 #endif
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
388 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
389
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
390 /*! BIT_lookBitsFast() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
391 * unsafe version; only works if nbBits >= 1 */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
392 MEM_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t* bitD, U32 nbBits)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
393 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
394 U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
395 assert(nbBits >= 1);
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
396 return (bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> (((regMask+1)-nbBits) & regMask);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
397 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
398
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
399 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
400 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
401 bitD->bitsConsumed += nbBits;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
402 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
403
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
404 /*! BIT_readBits() :
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
405 * Read (consume) next n bits from local register and update.
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
406 * Pay attention to not read more than nbBits contained into local register.
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
407 * @return : extracted value. */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
408 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
409 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
410 size_t const value = BIT_lookBits(bitD, nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
411 BIT_skipBits(bitD, nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
412 return value;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
413 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
414
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
415 /*! BIT_readBitsFast() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
416 * unsafe version; only works only if nbBits >= 1 */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
417 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
418 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
419 size_t const value = BIT_lookBitsFast(bitD, nbBits);
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
420 assert(nbBits >= 1);
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
421 BIT_skipBits(bitD, nbBits);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
422 return value;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
423 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
424
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
425 /*! BIT_reloadDStream() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
426 * Refill `bitD` from buffer previously set in BIT_initDStream() .
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
427 * This function is safe, it guarantees it will not read beyond src buffer.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
428 * @return : status of `BIT_DStream_t` internal register.
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
429 * when status == BIT_DStream_unfinished, internal register is filled with at least 25 or 57 bits */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
430 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
431 {
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
432 if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8)) /* overflow detected, like end of stream */
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
433 return BIT_DStream_overflow;
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
434
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
435 if (bitD->ptr >= bitD->limitPtr) {
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
436 bitD->ptr -= bitD->bitsConsumed >> 3;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
437 bitD->bitsConsumed &= 7;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
438 bitD->bitContainer = MEM_readLEST(bitD->ptr);
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
439 return BIT_DStream_unfinished;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
440 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
441 if (bitD->ptr == bitD->start) {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
442 if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
443 return BIT_DStream_completed;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
444 }
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
445 /* start < ptr < limitPtr */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
446 { U32 nbBytes = bitD->bitsConsumed >> 3;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
447 BIT_DStream_status result = BIT_DStream_unfinished;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
448 if (bitD->ptr - nbBytes < bitD->start) {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
449 nbBytes = (U32)(bitD->ptr - bitD->start); /* ptr > start */
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
450 result = BIT_DStream_endOfBuffer;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
451 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
452 bitD->ptr -= nbBytes;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
453 bitD->bitsConsumed -= nbBytes*8;
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
454 bitD->bitContainer = MEM_readLEST(bitD->ptr); /* reminder : srcSize > sizeof(bitD->bitContainer), otherwise bitD->ptr == bitD->start */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
455 return result;
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
456 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
457 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
458
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
459 /*! BIT_endOfDStream() :
37495
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
460 * @return : 1 if DStream has _exactly_ reached its end (all bits consumed).
b1fb341d8a61 zstandard: vendor python-zstandard 0.9.0
Gregory Szorc <gregory.szorc@gmail.com>
parents: 30822
diff changeset
461 */
30434
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
462 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
463 {
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
464 return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
465 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
466
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
467 #if defined (__cplusplus)
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
468 }
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
469 #endif
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
470
2e484bdea8c4 zstd: vendor zstd 1.1.1
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
471 #endif /* BITSTREAM_H_MODULE */