mirror of
https://github.com/google/brotli.git
synced 2024-11-21 19:20:09 +00:00
Add the initial version of the static dictionary and transforms to Brotli.
This commit is contained in:
Zoltan Szabadka
parent
0454ab4ec0
commit
2f268ad158
2208
brotlispec.txt
2208
brotlispec.txt
File diff suppressed because it is too large
Load Diff
45
dec/decode.c
45
dec/decode.c
@ -19,6 +19,8 @@
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#include "./bit_reader.h"
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#include "./context.h"
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#include "./decode.h"
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#include "./dictionary.h"
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#include "./transform.h"
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#include "./huffman.h"
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#include "./prefix.h"
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#include "./safe_malloc.h"
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@ -977,11 +979,44 @@ int BrotliDecompress(BrotliInput input, BrotliOutput output) {
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copy_dst = &ringbuffer[pos & ringbuffer_mask];
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if (distance > max_distance) {
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printf("Invalid backward reference. pos: %d distance: %d "
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"len: %d bytes left: %d\n", pos, distance, copy_length,
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meta_block_remaining_len);
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ok = 0;
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goto End;
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if (copy_length >= 3 && copy_length <= kMaxDictionaryWordLength) {
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int offset = kBrotliDictionaryOffsetsByLength[copy_length];
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int word_id = distance - max_distance - 1;
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int shift = kBrotliDictionarySizeBitsByLength[copy_length];
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int mask = (1 << shift) - 1;
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int word_idx = word_id & mask;
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int transform_idx = word_id >> shift;
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offset += word_idx * copy_length;
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if (transform_idx < kNumTransforms) {
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const uint8_t* word = &kBrotliDictionary[offset];
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int len = TransformDictionaryWord(
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copy_dst, word, copy_length, transform_idx);
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copy_dst += len;
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pos += len;
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meta_block_remaining_len -= len;
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if (copy_dst >= ringbuffer_end) {
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if (BrotliWrite(output, ringbuffer,
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(size_t)ringbuffer_size) < 0) {
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ok = 0;
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goto End;
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}
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memcpy(ringbuffer, ringbuffer_end,
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(size_t)(copy_dst - ringbuffer_end));
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}
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} else {
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printf("Invalid backward reference. pos: %d distance: %d "
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"len: %d bytes left: %d\n", pos, distance, copy_length,
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meta_block_remaining_len);
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ok = 0;
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goto End;
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}
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} else {
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printf("Invalid backward reference. pos: %d distance: %d "
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"len: %d bytes left: %d\n", pos, distance, copy_length,
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meta_block_remaining_len);
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ok = 0;
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goto End;
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}
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} else {
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if (copy_length > meta_block_remaining_len) {
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printf("Invalid backward reference. pos: %d distance: %d "
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4984
dec/dictionary.h
Normal file
4984
dec/dictionary.h
Normal file
File diff suppressed because it is too large
Load Diff
202
dec/transform.h
Normal file
202
dec/transform.h
Normal file
@ -0,0 +1,202 @@
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/* Copyright 2013 Google Inc. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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Transformations on dictionary words.
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*/
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#ifndef BROTLI_DEC_TRANSFORM_H_
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#define BROTLI_DEC_TRANSFORM_H_
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#include <stdio.h>
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#include <ctype.h>
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#include "./types.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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enum WordTransformType {
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kIdentity = 0,
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kOmit1 = 1,
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kOmit2 = 2,
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kOmit3 = 3,
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kOmit4 = 4,
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kOmit5 = 5,
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kOmit6 = 6,
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kOmit7 = 7,
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kOmit8 = 8,
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kOmit9 = 9,
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kUppercaseFirst = 10,
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kUppercaseAll = 11
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};
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typedef struct {
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const char* prefix;
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enum WordTransformType transform;
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const char* suffix;
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} Transform;
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static const Transform kTransforms[] = {
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{ "", kIdentity, "" },
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{ "", kIdentity, " ", },
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{ "", kIdentity, "\">" },
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{ "", kUppercaseFirst, "" },
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{ "", kIdentity, "\"" },
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{ "", kIdentity, ".", },
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{ "", kIdentity, "=\"" },
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{ "", kUppercaseFirst, " ", },
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{ " ", kIdentity, "=\"" },
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{ " ", kIdentity, " ", },
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{ "", kIdentity, ":", },
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{ " ", kIdentity, "" },
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{ "", kIdentity, "\n" },
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{ "", kIdentity, "(", },
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{ "", kUppercaseAll, "" },
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{ ".", kIdentity, "(", },
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{ "", kIdentity, "'" },
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{ "", kUppercaseFirst, "\"" },
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{ " ", kUppercaseFirst, " ", },
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{ "", kOmit3, "" },
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{ "", kOmit4, "" },
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{ ".", kIdentity, "" },
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{ "", kOmit1, "" },
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{ "", kOmit2, "" },
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{ "", kUppercaseFirst, "\">" },
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{ "", kOmit5, "" },
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{ "", kUppercaseAll, " ", },
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{ " ", kUppercaseFirst, "" },
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{ "", kIdentity, ", ", },
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{ "", kUppercaseFirst, "(", },
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{ "", kIdentity, "\n\t" },
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{ "", kUppercaseFirst, "'" },
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{ ".", kIdentity, " ", },
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{ " ", kUppercaseAll, " ", },
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{ "", kIdentity, "='" },
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{ "", kUppercaseFirst, ".", },
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{ " ", kIdentity, ".", },
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{ " ", kIdentity, ", ", },
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{ " ", kUppercaseAll, "" },
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{ "", kOmit6, "" },
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{ "", kOmit9, "" },
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{ "", kUppercaseAll, "\"" },
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{ "", kIdentity, " the " },
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{ "", kIdentity, " in " },
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{ "", kIdentity, " of " },
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{ "", kIdentity, " to " },
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{ "", kIdentity, " and " },
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{ "", kIdentity, " is " },
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{ "", kIdentity, " on " },
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{ "", kIdentity, " by " },
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{ "", kIdentity, " for " },
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{ "", kIdentity, " with " },
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{ "", kIdentity, " from " },
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{ "", kIdentity, " as " },
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{ "", kIdentity, " at " },
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{ "", kIdentity, "er " },
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{ " ", kIdentity, "='" },
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{ "", kIdentity, " a " },
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{ "", kOmit7, "" },
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{ "", kOmit8, "" },
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{ " ", kIdentity, "(", },
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{ " ", kIdentity, ". ", },
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{ "", kIdentity, ". ", },
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{ "", kIdentity, ",", },
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{ "", kOmit1, "ing " },
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{ "", kIdentity, "ed " },
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{ "", kUppercaseFirst, ", ", },
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{ "", kUppercaseAll, ".", },
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{ "", kUppercaseAll, "=\"" },
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{ "", kUppercaseAll, ", ", },
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{ "", kUppercaseAll, "\">" },
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{ " ", kUppercaseFirst, ".", },
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{ " ", kUppercaseAll, "=\"" },
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{ " ", kUppercaseFirst, ", ", },
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{ "", kUppercaseAll, "'" },
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{ "", kUppercaseFirst, "=\"" },
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{ " ", kIdentity, ",", },
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{ "", kIdentity, " that " },
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{ "", kUppercaseFirst, "='" },
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{ "", kUppercaseFirst, ". ", },
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{ "", kUppercaseFirst, ",", },
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{ "", kIdentity, ". The " },
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{ "\xc2\xa0", kIdentity, "" },
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{ " ", kUppercaseFirst, ". ", },
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{ "", kUppercaseAll, ",", },
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{ "", kUppercaseAll, "(", },
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{ " ", kUppercaseAll, "='" },
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{ "", kIdentity, "]" },
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{ "", kUppercaseAll, "='" },
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{ " ", kUppercaseAll, ".", },
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{ "", kUppercaseAll, ". ", },
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{ " ", kUppercaseFirst, "=\"" },
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{ " ", kUppercaseAll, ". ", },
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{ " ", kUppercaseFirst, ",", },
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{ " ", kUppercaseAll, ", ", },
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{ "", kIdentity, "ize " },
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{ " ", kUppercaseFirst, "='" },
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{ "", kIdentity, "est " },
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{ "", kIdentity, ". This " },
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};
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static const int kNumTransforms = sizeof(kTransforms) / sizeof(kTransforms[0]);
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static int ToUpperCase(uint8_t *p, int len) {
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if (p[0] < 0xc0) {
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if (p[0] >= 'a' && p[0] <= 'z') {
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p[0] ^= 32;
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}
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return 1;
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}
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/* An overly simplified uppercasing model for utf-8. */
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if (p[0] < 0xe0) {
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p[1] ^= 32;
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return 2;
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}
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/* An arbitrary transform for three byte characters. */
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p[2] ^= 5;
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return 3;
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}
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static BROTLI_INLINE int TransformDictionaryWord(
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uint8_t* dst, const uint8_t* word, int len, int transform) {
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const char* prefix = kTransforms[transform].prefix;
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const char* suffix = kTransforms[transform].suffix;
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const int t = kTransforms[transform].transform;
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int idx = 0;
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int i = 0;
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uint8_t* uppercase;
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while (*prefix) { dst[idx++] = (uint8_t)*prefix++; }
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if (t <= kOmit9) {
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len -= t;
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}
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while (i < len) { dst[idx++] = word[i++]; }
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uppercase = &dst[idx - len];
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if (t == kUppercaseFirst) {
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ToUpperCase(uppercase, len);
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} else if (t == kUppercaseAll) {
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while (len > 0) {
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int step = ToUpperCase(uppercase, len);
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uppercase += step;
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len -= step;
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}
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}
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while (*suffix) { dst[idx++] = (uint8_t)*suffix++; }
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return idx;
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}
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#if defined(__cplusplus) || defined(c_plusplus)
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} /* extern "C" */
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#endif
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#endif /* BROTLI_DEC_TRANSFORM_H_ */
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4973
enc/dictionary.h
Normal file
4973
enc/dictionary.h
Normal file
File diff suppressed because it is too large
Load Diff
@ -24,6 +24,7 @@
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#include "./block_splitter.h"
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#include "./cluster.h"
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#include "./context.h"
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#include "./transform.h"
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#include "./entropy_encode.h"
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#include "./fast_log.h"
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#include "./hash.h"
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@ -858,6 +859,7 @@ BrotliCompressor::BrotliCompressor()
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dist_ringbuffer_[2] = 11;
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dist_ringbuffer_[3] = 4;
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storage_[0] = 0;
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StoreDictionaryWordHashes();
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}
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BrotliCompressor::~BrotliCompressor() {
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@ -865,6 +867,22 @@ BrotliCompressor::~BrotliCompressor() {
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delete[] storage_;
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}
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void BrotliCompressor::StoreDictionaryWordHashes() {
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for (int t = kNumTransforms - 1; t >= 0; --t) {
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for (int i = kMaxDictionaryWordLength; i >= 3; --i) {
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const int num_words = 1 << kBrotliDictionarySizeBitsByLength[i];
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for (int j = num_words - 1; j >= 0; --j) {
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int word_id = t * num_words + j;
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std::string word = GetTransformedDictionaryWord(i, word_id);
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if (word.size() >= 3) {
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hasher_->Store(reinterpret_cast<const uint8_t*>(&word[0]),
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(-1) * ((i << 20) + word_id + 1));
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}
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}
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}
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}
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}
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void BrotliCompressor::WriteStreamHeader() {
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// Encode window size.
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if (window_bits_ == 16) {
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@ -50,6 +50,9 @@ class BrotliCompressor {
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private:
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// Initializes the hasher with the hashes of dictionary words.
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void StoreDictionaryWordHashes();
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int window_bits_;
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Hasher* hasher_;
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int dist_ringbuffer_[4];
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38
enc/hash.h
38
enc/hash.h
@ -24,7 +24,9 @@
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#include <sys/types.h>
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#include <algorithm>
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#include <cstdlib>
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#include <string>
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#include "./transform.h"
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#include "./fast_log.h"
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#include "./find_match_length.h"
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#include "./port.h"
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@ -276,7 +278,41 @@ class HashLongestMatch {
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for (int i = num_[key] - 1; i >= down; --i) {
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int prev_ix = bucket[i & kBlockMask];
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if (prev_ix < 0) {
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continue;
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prev_ix *= -1;
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prev_ix -= 1;
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int copy_len_code = prev_ix >> 20;
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int word_id = prev_ix & 0xfffff;
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std::string word = GetTransformedDictionaryWord(copy_len_code, word_id);
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int len = word.size();
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const size_t backward = max_backward + word_id + 1;
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bool word_matched = (len >= 3 && len <= max_length);
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for (int k = 0; k < len && word_matched; ++k) {
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if ((uint8_t)(word[k]) != data[cur_ix_masked + k]) {
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word_matched = false;
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}
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}
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if (word_matched) {
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const double score = BackwardReferenceScore(average_cost_,
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start_cost4,
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start_cost3,
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start_cost2,
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len, backward,
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last_distance1_,
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last_distance2_,
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last_distance3_,
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last_distance4_);
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if (best_score < score) {
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best_score = score;
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best_len = len;
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best_ix = backward;
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*best_len_out = best_len;
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*best_len_code_out = copy_len_code;
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*best_distance_out = best_ix;
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*best_score_out = best_score;
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match_found = true;
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*in_dictionary = true;
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}
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}
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} else {
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const size_t backward = cur_ix - prev_ix;
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if (PREDICT_FALSE(backward > max_backward)) {
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204
enc/transform.h
Normal file
204
enc/transform.h
Normal file
@ -0,0 +1,204 @@
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// Copyright 2010 Google Inc. All Rights Reserved.
|
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//
|
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// Licensed under the Apache License, Version 2.0 (the "License");
|
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// you may not use this file except in compliance with the License.
|
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// You may obtain a copy of the License at
|
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//
|
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// http://www.apache.org/licenses/LICENSE-2.0
|
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//
|
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// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
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//
|
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// Transformations on dictionary words.
|
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|
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#ifndef BROTLI_ENC_TRANSFORM_H_
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#define BROTLI_ENC_TRANSFORM_H_
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|
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#include <string>
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|
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#include "./dictionary.h"
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namespace brotli {
|
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|
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enum WordTransformType {
|
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kIdentity = 0,
|
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kOmit1 = 1,
|
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kOmit2 = 2,
|
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kOmit3 = 3,
|
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kOmit4 = 4,
|
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kOmit5 = 5,
|
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kOmit6 = 6,
|
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kOmit7 = 7,
|
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kOmit8 = 8,
|
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kOmit9 = 9,
|
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kUppercaseFirst = 10,
|
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kUppercaseAll = 11,
|
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};
|
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|
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struct Transform {
|
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const char* prefix;
|
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WordTransformType word_transform;
|
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const char* suffix;
|
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};
|
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|
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static const Transform kTransforms[] = {
|
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{ "", kIdentity, "" },
|
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{ "", kIdentity, " ", },
|
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{ "", kIdentity, "\">" },
|
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{ "", kUppercaseFirst, "" },
|
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{ "", kIdentity, "\"" },
|
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{ "", kIdentity, ".", },
|
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{ "", kIdentity, "=\"" },
|
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{ "", kUppercaseFirst, " ", },
|
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{ " ", kIdentity, "=\"" },
|
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{ " ", kIdentity, " ", },
|
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{ "", kIdentity, ":", },
|
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{ " ", kIdentity, "" },
|
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{ "", kIdentity, "\n" },
|
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{ "", kIdentity, "(", },
|
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{ "", kUppercaseAll, "" },
|
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{ ".", kIdentity, "(", },
|
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{ "", kIdentity, "'" },
|
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{ "", kUppercaseFirst, "\"" },
|
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{ " ", kUppercaseFirst, " ", },
|
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{ "", kOmit3, "" },
|
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{ "", kOmit4, "" },
|
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{ ".", kIdentity, "" },
|
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{ "", kOmit1, "" },
|
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{ "", kOmit2, "" },
|
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{ "", kUppercaseFirst, "\">" },
|
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{ "", kOmit5, "" },
|
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{ "", kUppercaseAll, " ", },
|
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{ " ", kUppercaseFirst, "" },
|
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{ "", kIdentity, ", ", },
|
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{ "", kUppercaseFirst, "(", },
|
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{ "", kIdentity, "\n\t" },
|
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{ "", kUppercaseFirst, "'" },
|
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{ ".", kIdentity, " ", },
|
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{ " ", kUppercaseAll, " ", },
|
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{ "", kIdentity, "='" },
|
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{ "", kUppercaseFirst, ".", },
|
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{ " ", kIdentity, ".", },
|
||||
{ " ", kIdentity, ", ", },
|
||||
{ " ", kUppercaseAll, "" },
|
||||
{ "", kOmit6, "" },
|
||||
{ "", kOmit9, "" },
|
||||
{ "", kUppercaseAll, "\"" },
|
||||
{ "", kIdentity, " the " },
|
||||
{ "", kIdentity, " in " },
|
||||
{ "", kIdentity, " of " },
|
||||
{ "", kIdentity, " to " },
|
||||
{ "", kIdentity, " and " },
|
||||
{ "", kIdentity, " is " },
|
||||
{ "", kIdentity, " on " },
|
||||
{ "", kIdentity, " by " },
|
||||
{ "", kIdentity, " for " },
|
||||
{ "", kIdentity, " with " },
|
||||
{ "", kIdentity, " from " },
|
||||
{ "", kIdentity, " as " },
|
||||
{ "", kIdentity, " at " },
|
||||
{ "", kIdentity, "er " },
|
||||
{ " ", kIdentity, "='" },
|
||||
{ "", kIdentity, " a " },
|
||||
{ "", kOmit7, "" },
|
||||
{ "", kOmit8, "" },
|
||||
{ " ", kIdentity, "(", },
|
||||
{ " ", kIdentity, ". ", },
|
||||
{ "", kIdentity, ". ", },
|
||||
{ "", kIdentity, ",", },
|
||||
{ "", kOmit1, "ing " },
|
||||
{ "", kIdentity, "ed " },
|
||||
{ "", kUppercaseFirst, ", ", },
|
||||
{ "", kUppercaseAll, ".", },
|
||||
{ "", kUppercaseAll, "=\"" },
|
||||
{ "", kUppercaseAll, ", ", },
|
||||
{ "", kUppercaseAll, "\">" },
|
||||
{ " ", kUppercaseFirst, ".", },
|
||||
{ " ", kUppercaseAll, "=\"" },
|
||||
{ " ", kUppercaseFirst, ", ", },
|
||||
{ "", kUppercaseAll, "'" },
|
||||
{ "", kUppercaseFirst, "=\"" },
|
||||
{ " ", kIdentity, ",", },
|
||||
{ "", kIdentity, " that " },
|
||||
{ "", kUppercaseFirst, "='" },
|
||||
{ "", kUppercaseFirst, ". ", },
|
||||
{ "", kUppercaseFirst, ",", },
|
||||
{ "", kIdentity, ". The " },
|
||||
{ "\xc2\xa0", kIdentity, "" },
|
||||
{ " ", kUppercaseFirst, ". ", },
|
||||
{ "", kUppercaseAll, ",", },
|
||||
{ "", kUppercaseAll, "(", },
|
||||
{ " ", kUppercaseAll, "='" },
|
||||
{ "", kIdentity, "]" },
|
||||
{ "", kUppercaseAll, "='" },
|
||||
{ " ", kUppercaseAll, ".", },
|
||||
{ "", kUppercaseAll, ". ", },
|
||||
{ " ", kUppercaseFirst, "=\"" },
|
||||
{ " ", kUppercaseAll, ". ", },
|
||||
{ " ", kUppercaseFirst, ",", },
|
||||
{ " ", kUppercaseAll, ", ", },
|
||||
{ "", kIdentity, "ize " },
|
||||
{ " ", kUppercaseFirst, "='" },
|
||||
{ "", kIdentity, "est " },
|
||||
{ "", kIdentity, ". This " },
|
||||
};
|
||||
|
||||
static const int kNumTransforms = sizeof(kTransforms) / sizeof(kTransforms[0]);
|
||||
|
||||
static int ToUpperCase(uint8_t *p, int len) {
|
||||
if (len == 1 || p[0] < 0xc0) {
|
||||
if (p[0] >= 'a' && p[0] <= 'z') {
|
||||
p[0] ^= 32;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
if (p[0] < 0xe0) {
|
||||
p[1] ^= 32;
|
||||
return 2;
|
||||
}
|
||||
if (len == 2) {
|
||||
return 2;
|
||||
}
|
||||
p[2] ^= 5;
|
||||
return 3;
|
||||
}
|
||||
|
||||
inline std::string ApplyTransform(
|
||||
const Transform& t, const uint8_t* word, int len) {
|
||||
std::string ret(t.prefix);
|
||||
if (t.word_transform <= kOmit9) {
|
||||
len -= t.word_transform;
|
||||
}
|
||||
if (len > 0) {
|
||||
ret += std::string(word, word + len);
|
||||
uint8_t *uppercase = reinterpret_cast<uint8_t*>(&ret[ret.size() - len]);
|
||||
if (t.word_transform == kUppercaseFirst) {
|
||||
ToUpperCase(uppercase, len);
|
||||
} else if (t.word_transform == kUppercaseAll) {
|
||||
while (len > 0) {
|
||||
int step = ToUpperCase(uppercase, len);
|
||||
uppercase += step;
|
||||
len -= step;
|
||||
}
|
||||
}
|
||||
}
|
||||
ret += std::string(t.suffix);
|
||||
return ret;
|
||||
}
|
||||
|
||||
inline std::string GetTransformedDictionaryWord(int len_code, int word_id) {
|
||||
int num_words = 1 << kBrotliDictionarySizeBitsByLength[len_code];
|
||||
int offset = kBrotliDictionaryOffsetsByLength[len_code];
|
||||
int t = word_id / num_words;
|
||||
int word_idx = word_id % num_words;
|
||||
offset += len_code * word_idx;
|
||||
const uint8_t* word = &kBrotliDictionary[offset];
|
||||
return ApplyTransform(kTransforms[t], word, len_code);
|
||||
}
|
||||
|
||||
} // namespace brotli
|
||||
|
||||
#endif // BROTLI_ENC_TRANSFORM_H_
|
||||
Loading…
Reference in New Issue
Block a user