Eugene Klyuchnikov | 771eb10 | 2015-11-27 11:27:11 +0100 | [diff] [blame] | 1 | /* Copyright 2013 Google Inc. All Rights Reserved. |
| 2 | |
Eugene Klyuchnikov | 24ffa78 | 2015-12-11 11:11:51 +0100 | [diff] [blame] | 3 | Distributed under MIT license. |
Eugene Klyuchnikov | 771eb10 | 2015-11-27 11:27:11 +0100 | [diff] [blame] | 4 | See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
| 5 | */ |
| 6 | |
Eugene Kliuchnikov | 352b0b2 | 2016-06-03 11:19:23 +0200 | [diff] [blame] | 7 | /* This class models a sequence of literals and a backward reference copy. */ |
Zoltan Szabadka | c66e4e3 | 2013-10-23 13:06:13 +0200 | [diff] [blame] | 8 | |
| 9 | #ifndef BROTLI_ENC_COMMAND_H_ |
| 10 | #define BROTLI_ENC_COMMAND_H_ |
| 11 | |
Eugene Kliuchnikov | 8148001 | 2016-08-23 14:40:33 +0200 | [diff] [blame] | 12 | #include <brotli/types.h> |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 13 | #include "../common/port.h" |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 14 | #include "./fast_log.h" |
Lode Vandevenne | 6511d6b | 2015-08-28 16:09:23 +0200 | [diff] [blame] | 15 | #include "./prefix.h" |
Zoltan Szabadka | c66e4e3 | 2013-10-23 13:06:13 +0200 | [diff] [blame] | 16 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 17 | #if defined(__cplusplus) || defined(c_plusplus) |
| 18 | extern "C" { |
| 19 | #endif |
Zoltan Szabadka | c66e4e3 | 2013-10-23 13:06:13 +0200 | [diff] [blame] | 20 | |
Zoltan Szabadka | 8844b7f | 2016-01-07 16:27:49 +0100 | [diff] [blame] | 21 | static uint32_t kInsBase[] = { 0, 1, 2, 3, 4, 5, 6, 8, 10, 14, 18, 26, 34, 50, |
| 22 | 66, 98, 130, 194, 322, 578, 1090, 2114, 6210, 22594 }; |
| 23 | static uint32_t kInsExtra[] = { 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, |
| 24 | 5, 5, 6, 7, 8, 9, 10, 12, 14, 24 }; |
| 25 | static uint32_t kCopyBase[] = { 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 18, 22, 30, |
| 26 | 38, 54, 70, 102, 134, 198, 326, 582, 1094, 2118 }; |
| 27 | static uint32_t kCopyExtra[] = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, |
| 28 | 4, 4, 5, 5, 6, 7, 8, 9, 10, 24 }; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 29 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 30 | static BROTLI_INLINE uint16_t GetInsertLengthCode(size_t insertlen) { |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 31 | if (insertlen < 6) { |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 32 | return (uint16_t)insertlen; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 33 | } else if (insertlen < 130) { |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 34 | uint32_t nbits = Log2FloorNonZero(insertlen - 2) - 1u; |
| 35 | return (uint16_t)((nbits << 1) + ((insertlen - 2) >> nbits) + 2); |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 36 | } else if (insertlen < 2114) { |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 37 | return (uint16_t)(Log2FloorNonZero(insertlen - 66) + 10); |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 38 | } else if (insertlen < 6210) { |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 39 | return 21u; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 40 | } else if (insertlen < 22594) { |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 41 | return 22u; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 42 | } else { |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 43 | return 23u; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 44 | } |
| 45 | } |
| 46 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 47 | static BROTLI_INLINE uint16_t GetCopyLengthCode(size_t copylen) { |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 48 | if (copylen < 10) { |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 49 | return (uint16_t)(copylen - 2); |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 50 | } else if (copylen < 134) { |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 51 | uint32_t nbits = Log2FloorNonZero(copylen - 6) - 1u; |
| 52 | return (uint16_t)((nbits << 1) + ((copylen - 6) >> nbits) + 4); |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 53 | } else if (copylen < 2118) { |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 54 | return (uint16_t)(Log2FloorNonZero(copylen - 70) + 12); |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 55 | } else { |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 56 | return 23u; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 57 | } |
| 58 | } |
| 59 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 60 | static BROTLI_INLINE uint16_t CombineLengthCodes( |
Eugene Kliuchnikov | 2048189 | 2016-07-26 14:41:59 +0200 | [diff] [blame] | 61 | uint16_t inscode, uint16_t copycode, BROTLI_BOOL use_last_distance) { |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 62 | uint16_t bits64 = |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 63 | (uint16_t)((copycode & 0x7u) | ((inscode & 0x7u) << 3)); |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 64 | if (use_last_distance && inscode < 8 && copycode < 16) { |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 65 | return (copycode < 8) ? bits64 : (bits64 | 64); |
| 66 | } else { |
Eugene Kliuchnikov | 352b0b2 | 2016-06-03 11:19:23 +0200 | [diff] [blame] | 67 | /* "To convert an insert-and-copy length code to an insert length code and |
| 68 | a copy length code, the following table can be used" */ |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 69 | static const uint16_t cells[9] = { 128u, 192u, 384u, 256u, 320u, 512u, |
| 70 | 448u, 576u, 640u }; |
| 71 | return cells[(copycode >> 3) + 3 * (inscode >> 3)] | bits64; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 72 | } |
| 73 | } |
| 74 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 75 | static BROTLI_INLINE void GetLengthCode(size_t insertlen, size_t copylen, |
Eugene Kliuchnikov | 2048189 | 2016-07-26 14:41:59 +0200 | [diff] [blame] | 76 | BROTLI_BOOL use_last_distance, |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 77 | uint16_t* code) { |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 78 | uint16_t inscode = GetInsertLengthCode(insertlen); |
| 79 | uint16_t copycode = GetCopyLengthCode(copylen); |
Zoltan Szabadka | ea48ce5 | 2015-10-28 17:44:47 +0100 | [diff] [blame] | 80 | *code = CombineLengthCodes(inscode, copycode, use_last_distance); |
Zoltan Szabadka | b820c39 | 2016-03-15 10:50:16 +0100 | [diff] [blame] | 81 | } |
| 82 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 83 | static BROTLI_INLINE uint32_t GetInsertBase(uint16_t inscode) { |
Zoltan Szabadka | b820c39 | 2016-03-15 10:50:16 +0100 | [diff] [blame] | 84 | return kInsBase[inscode]; |
| 85 | } |
| 86 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 87 | static BROTLI_INLINE uint32_t GetInsertExtra(uint16_t inscode) { |
Zoltan Szabadka | b820c39 | 2016-03-15 10:50:16 +0100 | [diff] [blame] | 88 | return kInsExtra[inscode]; |
| 89 | } |
| 90 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 91 | static BROTLI_INLINE uint32_t GetCopyBase(uint16_t copycode) { |
Zoltan Szabadka | b820c39 | 2016-03-15 10:50:16 +0100 | [diff] [blame] | 92 | return kCopyBase[copycode]; |
| 93 | } |
| 94 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 95 | static BROTLI_INLINE uint32_t GetCopyExtra(uint16_t copycode) { |
Zoltan Szabadka | b820c39 | 2016-03-15 10:50:16 +0100 | [diff] [blame] | 96 | return kCopyExtra[copycode]; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 97 | } |
| 98 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 99 | typedef struct Command { |
Zoltan Szabadka | 8844b7f | 2016-01-07 16:27:49 +0100 | [diff] [blame] | 100 | uint32_t insert_len_; |
Zoltan Szabadka | b820c39 | 2016-03-15 10:50:16 +0100 | [diff] [blame] | 101 | /* Stores copy_len in low 24 bits and copy_len XOR copy_code in high 8 bit. */ |
Zoltan Szabadka | 8844b7f | 2016-01-07 16:27:49 +0100 | [diff] [blame] | 102 | uint32_t copy_len_; |
Zoltan Szabadka | b4f39bf | 2014-10-28 13:25:22 +0100 | [diff] [blame] | 103 | uint32_t dist_extra_; |
Zoltan Szabadka | 14d6ae7 | 2016-01-26 11:25:53 +0100 | [diff] [blame] | 104 | uint16_t cmd_prefix_; |
| 105 | uint16_t dist_prefix_; |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 106 | } Command; |
Zoltan Szabadka | c66e4e3 | 2013-10-23 13:06:13 +0200 | [diff] [blame] | 107 | |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 108 | /* distance_code is e.g. 0 for same-as-last short code, or 16 for offset 1. */ |
| 109 | static BROTLI_INLINE void InitCommand(Command* self, size_t insertlen, |
| 110 | size_t copylen, size_t copylen_code, size_t distance_code) { |
| 111 | self->insert_len_ = (uint32_t)insertlen; |
| 112 | self->copy_len_ = (uint32_t)(copylen | ((copylen_code ^ copylen) << 24)); |
| 113 | /* The distance prefix and extra bits are stored in this Command as if |
| 114 | npostfix and ndirect were 0, they are only recomputed later after the |
| 115 | clustering if needed. */ |
| 116 | PrefixEncodeCopyDistance( |
| 117 | distance_code, 0, 0, &self->dist_prefix_, &self->dist_extra_); |
| 118 | GetLengthCode( |
Eugene Kliuchnikov | 2048189 | 2016-07-26 14:41:59 +0200 | [diff] [blame] | 119 | insertlen, copylen_code, TO_BROTLI_BOOL(self->dist_prefix_ == 0), |
| 120 | &self->cmd_prefix_); |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | static BROTLI_INLINE void InitInsertCommand(Command* self, size_t insertlen) { |
| 124 | self->insert_len_ = (uint32_t)insertlen; |
| 125 | self->copy_len_ = 4 << 24; |
| 126 | self->dist_extra_ = 0; |
| 127 | self->dist_prefix_ = 16; |
Eugene Kliuchnikov | 2048189 | 2016-07-26 14:41:59 +0200 | [diff] [blame] | 128 | GetLengthCode(insertlen, 4, BROTLI_FALSE, &self->cmd_prefix_); |
Eugene Kliuchnikov | b972c67 | 2016-06-13 11:01:04 +0200 | [diff] [blame] | 129 | } |
| 130 | |
| 131 | static BROTLI_INLINE uint32_t CommandDistanceCode(const Command* self) { |
| 132 | if (self->dist_prefix_ < 16) { |
| 133 | return self->dist_prefix_; |
| 134 | } else { |
| 135 | uint32_t nbits = self->dist_extra_ >> 24; |
| 136 | uint32_t extra = self->dist_extra_ & 0xffffff; |
| 137 | uint32_t prefix = self->dist_prefix_ - 12u - 2u * nbits; |
| 138 | return (prefix << nbits) + extra + 12; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | static BROTLI_INLINE uint32_t CommandDistanceContext(const Command* self) { |
| 143 | uint32_t r = self->cmd_prefix_ >> 6; |
| 144 | uint32_t c = self->cmd_prefix_ & 7; |
| 145 | if ((r == 0 || r == 2 || r == 4 || r == 7) && (c <= 2)) { |
| 146 | return c; |
| 147 | } |
| 148 | return 3; |
| 149 | } |
| 150 | |
| 151 | static BROTLI_INLINE uint32_t CommandCopyLen(const Command* self) { |
| 152 | return self->copy_len_ & 0xFFFFFF; |
| 153 | } |
| 154 | |
| 155 | static BROTLI_INLINE uint32_t CommandCopyLenCode(const Command* self) { |
| 156 | return (self->copy_len_ & 0xFFFFFF) ^ (self->copy_len_ >> 24); |
| 157 | } |
| 158 | |
| 159 | #if defined(__cplusplus) || defined(c_plusplus) |
| 160 | } /* extern "C" */ |
| 161 | #endif |
Zoltan Szabadka | c66e4e3 | 2013-10-23 13:06:13 +0200 | [diff] [blame] | 162 | |
Eugene Kliuchnikov | 352b0b2 | 2016-06-03 11:19:23 +0200 | [diff] [blame] | 163 | #endif /* BROTLI_ENC_COMMAND_H_ */ |