/* Copyright 2010 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
// Transformations on dictionary words.
#ifndef BROTLI_ENC_TRANSFORM_H_
#define BROTLI_ENC_TRANSFORM_H_
#include <string>
#include "./dictionary.h"
namespace brotli {
enum WordTransformType {
kIdentity = 0,
kOmitLast1 = 1,
kOmitLast2 = 2,
kOmitLast3 = 3,
kOmitLast4 = 4,
kOmitLast5 = 5,
kOmitLast6 = 6,
kOmitLast7 = 7,
kOmitLast8 = 8,
kOmitLast9 = 9,
kUppercaseFirst = 10,
kUppercaseAll = 11,
kOmitFirst1 = 12,
kOmitFirst2 = 13,
kOmitFirst3 = 14,
kOmitFirst4 = 15,
kOmitFirst5 = 16,
kOmitFirst6 = 17,
kOmitFirst7 = 18,
kOmitFirst8 = 19,
kOmitFirst9 = 20
};
struct Transform {
const char* prefix;
WordTransformType word_transform;
const char* suffix;
};
static const Transform kTransforms[] = {
{ "", kIdentity, "" },
{ "", kIdentity, " " },
{ " ", kIdentity, " " },
{ "", kOmitFirst1, "" },
{ "", kUppercaseFirst, " " },
{ "", kIdentity, " the " },
{ " ", kIdentity, "" },
{ "s ", kIdentity, " " },
{ "", kIdentity, " of " },
{ "", kUppercaseFirst, "" },
{ "", kIdentity, " and " },
{ "", kOmitFirst2, "" },
{ "", kOmitLast1, "" },
{ ", ", kIdentity, " " },
{ "", kIdentity, ", " },
{ " ", kUppercaseFirst, " " },
{ "", kIdentity, " in " },
{ "", kIdentity, " to " },
{ "e ", kIdentity, " " },
{ "", kIdentity, "\"" },
{ "", kIdentity, "." },
{ "", kIdentity, "\">" },
{ "", kIdentity, "\n" },
{ "", kOmitLast3, "" },
{ "", kIdentity, "]" },
{ "", kIdentity, " for " },
{ "", kOmitFirst3, "" },
{ "", kOmitLast2, "" },
{ "", kIdentity, " a " },
{ "", kIdentity, " that " },
{ " ", kUppercaseFirst, "" },
{ "", kIdentity, ". " },
{ ".", kIdentity, "" },
{ " ", kIdentity, ", " },
{ "", kOmitFirst4, "" },
{ "", kIdentity, " with " },
{ "", kIdentity, "'" },
{ "", kIdentity, " from " },
{ "", kIdentity, " by " },
{ "", kOmitFirst5, "" },
{ "", kOmitFirst6, "" },
{ " the ", kIdentity, "" },
{ "", kOmitLast4, "" },
{ "", kIdentity, ". The " },
{ "", kUppercaseAll, "" },
{ "", kIdentity, " on " },
{ "", kIdentity, " as " },
{ "", kIdentity, " is " },
{ "", kOmitLast7, "" },
{ "", kOmitLast1, "ing " },
{ "", kIdentity, "\n\t" },
{ "", kIdentity, ":" },
{ " ", kIdentity, ". " },
{ "", kIdentity, "ed " },
{ "", kOmitFirst9, "" },
{ "", kOmitFirst7, "" },
{ "", kOmitLast6, "" },
{ "", kIdentity, "(" },
{ "", kUppercaseFirst, ", " },
{ "", kOmitLast8, "" },
{ "", kIdentity, " at " },
{ "", kIdentity, "ly " },
{ " the ", kIdentity, " of " },
{ "", kOmitLast5, "" },
{ "", kOmitLast9, "" },
{ " ", kUppercaseFirst, ", " },
{ "", kUppercaseFirst, "\"" },
{ ".", kIdentity, "(" },
{ "", kUppercaseAll, " " },
{ "", kUppercaseFirst, "\">" },
{ "", kIdentity, "=\"" },
{ " ", kIdentity, "." },
{ ".com/", kIdentity, "" },
{ " the ", kIdentity, " of the " },
{ "", kUppercaseFirst, "'" },
{ "", kIdentity, ". This " },
{ "", kIdentity, "," },
{ ".", kIdentity, " " },
{ "", kUppercaseFirst, "(" },
{ "", kUppercaseFirst, "." },
{ "", kIdentity, " not " },
{ " ", kIdentity, "=\"" },
{ "", kIdentity, "er " },
{ " ", kUppercaseAll, " " },
{ "", kIdentity, "al " },
{ " ", kUppercaseAll, "" },
{ "", kIdentity, "='" },
{ "", kUppercaseAll, "\"" },
{ "", kUppercaseFirst, ". " },
{ " ", kIdentity, "(" },
{ "", kIdentity, "ful " },
{ " ", kUppercaseFirst, ". " },
{ "", kIdentity, "ive " },
{ "", kIdentity, "less " },
{ "", kUppercaseAll, "'" },
{ "", kIdentity, "est " },
{ " ", kUppercaseFirst, "." },
{ "", kUppercaseAll, "\">" },
{ " ", kIdentity, "='" },
{ "", kUppercaseFirst, "," },
{ "", kIdentity, "ize " },
{ "", kUppercaseAll, "." },
{ "\xc2\xa0", kIdentity, "" },
{ " ", kIdentity, "," },
{ "", kUppercaseFirst, "=\"" },
{ "", kUppercaseAll, "=\"" },
{ "", kIdentity, "ous " },
{ "", kUppercaseAll, ", " },
{ "", kUppercaseFirst, "='" },
{ " ", kUppercaseFirst, "," },
{ " ", kUppercaseAll, "=\"" },
{ " ", kUppercaseAll, ", " },
{ "", kUppercaseAll, "," },
{ "", kUppercaseAll, "(" },
{ "", kUppercaseAll, ". " },
{ " ", kUppercaseAll, "." },
{ "", kUppercaseAll, "='" },
{ " ", kUppercaseAll, ". " },
{ " ", kUppercaseFirst, "=\"" },
{ " ", kUppercaseAll, "='" },
{ " ", kUppercaseFirst, "='" },
};
static const size_t kNumTransforms =
sizeof(kTransforms) / sizeof(kTransforms[0]);
static const size_t kOmitLastNTransforms[10] = {
0, 12, 27, 23, 42, 63, 56, 48, 59, 64,
};
static size_t ToUpperCase(uint8_t *p, size_t 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 TransformWord(
WordTransformType transform_type, const uint8_t* word, size_t len) {
if (transform_type <= kOmitLast9) {
if (len <= transform_type) {
return std::string();
}
return std::string(word, word + len - transform_type);
}
if (transform_type >= kOmitFirst1) {
const size_t skip = transform_type - (kOmitFirst1 - 1);
if (len <= skip) {
return std::string();
}
return std::string(word + skip, word + len);
}
std::string ret = std::string(word, word + len);
uint8_t *uppercase = reinterpret_cast<uint8_t*>(&ret[0]);
if (transform_type == kUppercaseFirst) {
ToUpperCase(uppercase, len);
} else if (transform_type == kUppercaseAll) {
size_t position = 0;
while (position < len) {
size_t step = ToUpperCase(uppercase, len - position);
uppercase += step;
position += step;
}
}
return ret;
}
inline std::string ApplyTransform(
const Transform& t, const uint8_t* word, size_t len) {
return std::string(t.prefix) +
TransformWord(t.word_transform, word, len) + std::string(t.suffix);
}
inline std::string GetTransformedDictionaryWord(size_t len_code,
size_t word_id) {
size_t num_words = 1u << kBrotliDictionarySizeBitsByLength[len_code];
size_t offset = kBrotliDictionaryOffsetsByLength[len_code];
size_t t = word_id / num_words;
size_t 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_
