mirror of
https://github.com/google/brotli.git
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243 lines
9.2 KiB
C++
243 lines
9.2 KiB
C++
// 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
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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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//
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// Transformations on dictionary words.
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#ifndef BROTLI_ENC_TRANSFORM_H_
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#define BROTLI_ENC_TRANSFORM_H_
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#include <string>
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#include "./dictionary.h"
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namespace brotli {
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enum WordTransformType {
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kIdentity = 0,
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kOmitLast1 = 1,
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kOmitLast2 = 2,
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kOmitLast3 = 3,
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kOmitLast4 = 4,
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kOmitLast5 = 5,
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kOmitLast6 = 6,
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kOmitLast7 = 7,
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kOmitLast8 = 8,
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kOmitLast9 = 9,
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kUppercaseFirst = 10,
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kUppercaseAll = 11,
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kOmitFirst1 = 12,
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kOmitFirst2 = 13,
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kOmitFirst3 = 14,
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kOmitFirst4 = 15,
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kOmitFirst5 = 16,
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kOmitFirst6 = 17,
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kOmitFirst7 = 18,
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kOmitFirst8 = 19,
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kOmitFirst9 = 20,
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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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static const Transform kTransforms[] = {
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{ "", kIdentity, "" },
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{ "", kIdentity, " " },
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{ " ", kIdentity, " " },
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{ "", kOmitFirst1, "" },
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{ "", kUppercaseFirst, " " },
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{ "", kIdentity, " the " },
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{ " ", kIdentity, "" },
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{ "s ", kIdentity, " " },
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{ "", kIdentity, " of " },
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{ "", kUppercaseFirst, "" },
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{ "", kIdentity, " and " },
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{ "", kOmitFirst2, "" },
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{ "", kOmitLast1, "" },
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{ ", ", kIdentity, " " },
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{ "", kIdentity, ", " },
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{ " ", kUppercaseFirst, " " },
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{ "", kIdentity, " in " },
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{ "", kIdentity, " to " },
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{ "e ", 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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{ "", kOmitLast3, "" },
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{ "", kIdentity, "]" },
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{ "", kIdentity, " for " },
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{ "", kOmitFirst3, "" },
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{ "", kOmitLast2, "" },
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{ "", kIdentity, " a " },
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{ "", kIdentity, " that " },
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{ " ", kUppercaseFirst, "" },
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{ "", kIdentity, ". " },
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{ ".", kIdentity, "" },
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{ " ", kIdentity, ", " },
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{ "", kOmitFirst4, "" },
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{ "", kIdentity, " with " },
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{ "", kIdentity, "'" },
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{ "", kIdentity, " from " },
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{ "", kIdentity, " by " },
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{ "", kOmitFirst5, "" },
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{ "", kOmitFirst6, "" },
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{ " the ", kIdentity, "" },
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{ "", kOmitLast4, "" },
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{ "", kIdentity, ". The " },
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{ "", kUppercaseAll, "" },
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{ "", kIdentity, " on " },
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{ "", kIdentity, " as " },
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{ "", kIdentity, " is " },
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{ "", kOmitLast7, "" },
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{ "", kOmitLast1, "ing " },
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{ "", kIdentity, "\n\t" },
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{ "", kIdentity, ":" },
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{ " ", kIdentity, ". " },
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{ "", kIdentity, "ed " },
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{ "", kOmitFirst9, "" },
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{ "", kOmitFirst7, "" },
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{ "", kOmitLast6, "" },
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{ "", kIdentity, "(" },
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{ "", kUppercaseFirst, ", " },
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{ "", kOmitLast8, "" },
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{ "", kIdentity, " at " },
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{ "", kIdentity, "ly " },
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{ " the ", kIdentity, " of " },
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{ "", kOmitLast5, "" },
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{ "", kOmitLast9, "" },
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{ " ", kUppercaseFirst, ", " },
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{ "", kUppercaseFirst, "\"" },
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{ ".", kIdentity, "(" },
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{ "", kUppercaseAll, " " },
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{ "", kUppercaseFirst, "\">" },
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{ "", kIdentity, "=\"" },
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{ " ", kIdentity, "." },
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{ ".com/", kIdentity, "" },
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{ " the ", kIdentity, " of the " },
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{ "", kUppercaseFirst, "'" },
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{ "", kIdentity, ". This " },
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{ "", kIdentity, "," },
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{ ".", kIdentity, " " },
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{ "", kUppercaseFirst, "(" },
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{ "", kUppercaseFirst, "." },
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{ "", kIdentity, " not " },
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{ " ", kIdentity, "=\"" },
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{ "", kIdentity, "er " },
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{ " ", kUppercaseAll, " " },
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{ "", kIdentity, "al " },
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{ " ", kUppercaseAll, "" },
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{ "", kIdentity, "='" },
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{ "", kUppercaseAll, "\"" },
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{ "", kUppercaseFirst, ". " },
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{ " ", kIdentity, "(" },
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{ "", kIdentity, "ful " },
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{ " ", kUppercaseFirst, ". " },
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{ "", kIdentity, "ive " },
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{ "", kIdentity, "less " },
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{ "", kUppercaseAll, "'" },
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{ "", kIdentity, "est " },
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{ " ", kUppercaseFirst, "." },
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{ "", kUppercaseAll, "\">" },
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{ " ", kIdentity, "='" },
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{ "", kUppercaseFirst, "," },
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{ "", kIdentity, "ize " },
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{ "", kUppercaseAll, "." },
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{ "\xc2\xa0", kIdentity, "" },
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{ " ", kIdentity, "," },
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{ "", kUppercaseFirst, "=\"" },
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{ "", kUppercaseAll, "=\"" },
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{ "", kIdentity, "ous " },
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{ "", kUppercaseAll, ", " },
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{ "", kUppercaseFirst, "='" },
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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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{ "", 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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};
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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 (len == 1 || 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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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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if (len == 2) {
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return 2;
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}
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p[2] ^= 5;
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return 3;
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}
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inline std::string ApplyTransform(
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const Transform& t, const uint8_t* word, int len) {
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std::string ret(t.prefix);
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if (t.word_transform <= kOmitLast9) {
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len -= t.word_transform;
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}
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if (len > 0) {
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if (t.word_transform >= kOmitFirst1) {
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const int skip = t.word_transform - (kOmitFirst1 - 1);
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if (len > skip) {
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ret += std::string(word + skip, word + len);
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}
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} else {
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ret += std::string(word, word + len);
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uint8_t *uppercase = reinterpret_cast<uint8_t*>(&ret[ret.size() - len]);
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if (t.word_transform == kUppercaseFirst) {
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ToUpperCase(uppercase, len);
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} else if (t.word_transform == 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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}
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}
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ret += std::string(t.suffix);
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return ret;
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}
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inline std::string GetTransformedDictionaryWord(int len_code, int word_id) {
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int num_words = 1 << kBrotliDictionarySizeBitsByLength[len_code];
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int offset = kBrotliDictionaryOffsetsByLength[len_code];
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int t = word_id / num_words;
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int word_idx = word_id % num_words;
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offset += len_code * word_idx;
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const uint8_t* word = &kBrotliDictionary[offset];
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return ApplyTransform(kTransforms[t], word, len_code);
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}
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} // namespace brotli
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#endif // BROTLI_ENC_TRANSFORM_H_
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