| #include "./static_dict.h" |
| |
| #include <algorithm> |
| |
| #include "./dictionary.h" |
| #include "./find_match_length.h" |
| #include "./static_dict_lut.h" |
| #include "./transform.h" |
| |
| namespace brotli { |
| |
| inline uint32_t Hash(const uint8_t *data) { |
| uint32_t h = BROTLI_UNALIGNED_LOAD32(data) * kDictHashMul32; |
| // The higher bits contain more mixture from the multiplication, |
| // so we take our results from there. |
| return h >> (32 - kDictNumBits); |
| } |
| |
| inline void AddMatch(int distance, int len, int len_code, int* matches) { |
| matches[len] = std::min(matches[len], (distance << 5) + len_code); |
| } |
| |
| inline int DictMatchLength(const uint8_t* data, int id, int len, int maxlen) { |
| const int offset = kBrotliDictionaryOffsetsByLength[len] + len * id; |
| return FindMatchLengthWithLimit(&kBrotliDictionary[offset], data, |
| std::min(len, maxlen)); |
| } |
| |
| inline bool IsMatch(DictWord w, const uint8_t* data, int max_length) { |
| if (w.len > max_length) return false; |
| const int offset = kBrotliDictionaryOffsetsByLength[w.len] + w.len * w.idx; |
| const uint8_t* dict = &kBrotliDictionary[offset]; |
| if (w.transform == 0) { |
| // Match against base dictionary word. |
| return FindMatchLengthWithLimit(dict, data, w.len) == w.len; |
| } else if (w.transform == 10) { |
| // Match against uppercase first transform. |
| // Note that there are only ASCII uppercase words in the lookup table. |
| return (dict[0] >= 'a' && dict[0] <= 'z' && |
| (dict[0] ^ 32) == data[0] && |
| FindMatchLengthWithLimit(&dict[1], &data[1], w.len - 1) == |
| w.len - 1); |
| } else { |
| // Match against uppercase all transform. |
| // Note that there are only ASCII uppercase words in the lookup table. |
| for (int i = 0; i < w.len; ++i) { |
| if (dict[i] >= 'a' && dict[i] <= 'z') { |
| if ((dict[i] ^ 32) != data[i]) return false; |
| } else { |
| if (dict[i] != data[i]) return false; |
| } |
| } |
| return true; |
| } |
| } |
| |
| bool FindAllStaticDictionaryMatches(const uint8_t* data, |
| int min_length, |
| int max_length, |
| int* matches) { |
| bool found_match = false; |
| uint32_t key = Hash(data); |
| uint32_t bucket = kStaticDictionaryBuckets[key]; |
| if (bucket != 0) { |
| int num = bucket & 0xff; |
| int offset = bucket >> 8; |
| for (int i = 0; i < num; ++i) { |
| const DictWord w = kStaticDictionaryWords[offset + i]; |
| const int l = w.len; |
| const int n = 1 << kBrotliDictionarySizeBitsByLength[l]; |
| const int id = w.idx; |
| if (w.transform == 0) { |
| const int matchlen = DictMatchLength(data, id, l, max_length); |
| // Transform "" + kIdentity + "" |
| if (matchlen == l) { |
| AddMatch(id, l, l, matches); |
| found_match = true; |
| } |
| // Transforms "" + kOmitLast1 + "" and "" + kOmitLast1 + "ing " |
| if (matchlen >= l - 1) { |
| AddMatch(id + 12 * n, l - 1, l, matches); |
| if (l + 2 < max_length && |
| data[l - 1] == 'i' && data[l] == 'n' && data[l + 1] == 'g' && |
| data[l + 2] == ' ') { |
| AddMatch(id + 49 * n, l + 3, l, matches); |
| } |
| found_match = true; |
| } |
| // Transform "" + kOmitLastN + "" (N = 2 .. 9) |
| int minlen = std::max<int>(min_length, l - 9); |
| int maxlen = std::min<int>(matchlen, l - 2); |
| for (int len = minlen; len <= maxlen; ++len) { |
| AddMatch(id + kOmitLastNTransforms[l - len] * n, len, l, matches); |
| found_match = true; |
| } |
| if (matchlen < l || l + 6 >= max_length) { |
| continue; |
| } |
| const uint8_t* s = &data[l]; |
| // Transforms "" + kIdentity + <suffix> |
| if (s[0] == ' ') { |
| AddMatch(id + n, l + 1, l, matches); |
| if (s[1] == 'a') { |
| if (s[2] == ' ') { |
| AddMatch(id + 28 * n, l + 3, l, matches); |
| } else if (s[2] == 's') { |
| if (s[3] == ' ') AddMatch(id + 46 * n, l + 4, l, matches); |
| } else if (s[2] == 't') { |
| if (s[3] == ' ') AddMatch(id + 60 * n, l + 4, l, matches); |
| } else if (s[2] == 'n') { |
| if (s[3] == 'd' && s[4] == ' ') { |
| AddMatch(id + 10 * n, l + 5, l, matches); |
| } |
| } |
| } else if (s[1] == 'b') { |
| if (s[2] == 'y' && s[3] == ' ') { |
| AddMatch(id + 38 * n, l + 4, l, matches); |
| } |
| } else if (s[1] == 'i') { |
| if (s[2] == 'n') { |
| if (s[3] == ' ') AddMatch(id + 16 * n, l + 4, l, matches); |
| } else if (s[2] == 's') { |
| if (s[3] == ' ') AddMatch(id + 47 * n, l + 4, l, matches); |
| } |
| } else if (s[1] == 'f') { |
| if (s[2] == 'o') { |
| if (s[3] == 'r' && s[4] == ' ') { |
| AddMatch(id + 25 * n, l + 5, l, matches); |
| } |
| } else if (s[2] == 'r') { |
| if (s[3] == 'o' && s[4] == 'm' && s[5] == ' ') { |
| AddMatch(id + 37 * n, l + 6, l, matches); |
| } |
| } |
| } else if (s[1] == 'o') { |
| if (s[2] == 'f') { |
| if (s[3] == ' ') AddMatch(id + 8 * n, l + 4, l, matches); |
| } else if (s[2] == 'n') { |
| if (s[3] == ' ') AddMatch(id + 45 * n, l + 4, l, matches); |
| } |
| } else if (s[1] == 'n') { |
| if (s[2] == 'o' && s[3] == 't' && s[4] == ' ') { |
| AddMatch(id + 80 * n, l + 5, l, matches); |
| } |
| } else if (s[1] == 't') { |
| if (s[2] == 'h') { |
| if (s[3] == 'e') { |
| if (s[4] == ' ') AddMatch(id + 5 * n, l + 5, l, matches); |
| } else if (s[3] == 'a') { |
| if (s[4] == 't' && s[5] == ' ') { |
| AddMatch(id + 29 * n, l + 6, l, matches); |
| } |
| } |
| } else if (s[2] == 'o') { |
| if (s[3] == ' ') AddMatch(id + 17 * n, l + 4, l, matches); |
| } |
| } else if (s[1] == 'w') { |
| if (s[2] == 'i' && s[3] == 't' && s[4] == 'h' && s[5] == ' ') { |
| AddMatch(id + 35 * n, l + 6, l, matches); |
| } |
| } |
| } else if (s[0] == '"') { |
| AddMatch(id + 19 * n, l + 1, l, matches); |
| if (s[1] == '>') { |
| AddMatch(id + 21 * n, l + 2, l, matches); |
| } |
| } else if (s[0] == '.') { |
| AddMatch(id + 20 * n, l + 1, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + 31 * n, l + 2, l, matches); |
| if (s[2] == 'T' && s[3] == 'h') { |
| if (s[4] == 'e') { |
| if (s[5] == ' ') AddMatch(id + 43 * n, l + 6, l, matches); |
| } else if (s[4] == 'i') { |
| if (s[5] == 's' && s[6] == ' ') { |
| AddMatch(id + 75 * n, l + 7, l, matches); |
| } |
| } |
| } |
| } |
| } else if (s[0] == ',') { |
| AddMatch(id + 76 * n, l + 1, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + 14 * n, l + 2, l, matches); |
| } |
| } else if (s[0] == '\n') { |
| AddMatch(id + 22 * n, l + 1, l, matches); |
| if (s[1] == '\t') { |
| AddMatch(id + 50 * n, l + 2, l, matches); |
| } |
| } else if (s[0] == ']') { |
| AddMatch(id + 24 * n, l + 1, l, matches); |
| } else if (s[0] == '\'') { |
| AddMatch(id + 36 * n, l + 1, l, matches); |
| } else if (s[0] == ':') { |
| AddMatch(id + 51 * n, l + 1, l, matches); |
| } else if (s[0] == '(') { |
| AddMatch(id + 57 * n, l + 1, l, matches); |
| } else if (s[0] == '=') { |
| if (s[1] == '"') { |
| AddMatch(id + 70 * n, l + 2, l, matches); |
| } else if (s[1] == '\'') { |
| AddMatch(id + 86 * n, l + 2, l, matches); |
| } |
| } else if (s[0] == 'a') { |
| if (s[1] == 'l' && s[2] == ' ') { |
| AddMatch(id + 84 * n, l + 3, l, matches); |
| } |
| } else if (s[0] == 'e') { |
| if (s[1] == 'd') { |
| if (s[2] == ' ') AddMatch(id + 53 * n, l + 3, l, matches); |
| } else if (s[1] == 'r') { |
| if (s[2] == ' ') AddMatch(id + 82 * n, l + 3, l, matches); |
| } else if (s[1] == 's') { |
| if (s[2] == 't' && s[3] == ' ') { |
| AddMatch(id + 95 * n, l + 4, l, matches); |
| } |
| } |
| } else if (s[0] == 'f') { |
| if (s[1] == 'u' && s[2] == 'l' && s[3] == ' ') { |
| AddMatch(id + 90 * n, l + 4, l, matches); |
| } |
| } else if (s[0] == 'i') { |
| if (s[1] == 'v') { |
| if (s[2] == 'e' && s[3] == ' ') { |
| AddMatch(id + 92 * n, l + 4, l, matches); |
| } |
| } else if (s[1] == 'z') { |
| if (s[2] == 'e' && s[3] == ' ') { |
| AddMatch(id + 100 * n, l + 4, l, matches); |
| } |
| } |
| } else if (s[0] == 'l') { |
| if (s[1] == 'e') { |
| if (s[2] == 's' && s[3] == 's' && s[4] == ' ') { |
| AddMatch(id + 93 * n, l + 5, l, matches); |
| } |
| } else if (s[1] == 'y') { |
| if (s[2] == ' ') AddMatch(id + 61 * n, l + 3, l, matches); |
| } |
| } else if (s[0] == 'o') { |
| if (s[1] == 'u' && s[2] == 's' && s[3] == ' ') { |
| AddMatch(id + 106 * n, l + 4, l, matches); |
| } |
| } |
| } else { |
| // Set t=0 for kUppercaseFirst and t=1 for kUppercaseAll transform. |
| const int t = w.transform - 10; |
| if (!IsMatch(w, data, max_length)) { |
| continue; |
| } |
| // Transform "" + kUppercase{First,All} + "" |
| AddMatch(id + (t ? 44 : 9) * n, l, l, matches); |
| found_match = true; |
| if (l + 1 >= max_length) { |
| continue; |
| } |
| // Transforms "" + kUppercase{First,All} + <suffix> |
| const uint8_t* s = &data[l]; |
| if (s[0] == ' ') { |
| AddMatch(id + (t ? 68 : 4) * n, l + 1, l, matches); |
| } else if (s[0] == '"') { |
| AddMatch(id + (t ? 87 : 66) * n, l + 1, l, matches); |
| if (s[1] == '>') { |
| AddMatch(id + (t ? 97 : 69) * n, l + 2, l, matches); |
| } |
| } else if (s[0] == '.') { |
| AddMatch(id + (t ? 101 : 79) * n, l + 1, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + (t ? 114 : 88) * n, l + 2, l, matches); |
| } |
| } else if (s[0] == ',') { |
| AddMatch(id + (t ? 112 : 99) * n, l + 1, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + (t ? 107 : 58) * n, l + 2, l, matches); |
| } |
| } else if (s[0] == '\'') { |
| AddMatch(id + (t ? 94 : 74) * n, l + 1, l, matches); |
| } else if (s[0] == '(') { |
| AddMatch(id + (t ? 113 : 78) * n, l + 1, l, matches); |
| } else if (s[0] == '=') { |
| if (s[1] == '"') { |
| AddMatch(id + (t ? 105 : 104) * n, l + 2, l, matches); |
| } else if (s[1] == '\'') { |
| AddMatch(id + (t ? 116 : 108) * n, l + 2, l, matches); |
| } |
| } |
| } |
| } |
| } |
| // Transforms with prefixes " " and "." |
| if (max_length >= 5 && (data[0] == ' ' || data[0] == '.')) { |
| bool is_space = (data[0] == ' '); |
| key = Hash(&data[1]); |
| bucket = kStaticDictionaryBuckets[key]; |
| int num = bucket & 0xff; |
| int offset = bucket >> 8; |
| for (int i = 0; i < num; ++i) { |
| const DictWord w = kStaticDictionaryWords[offset + i]; |
| const int l = w.len; |
| const int n = 1 << kBrotliDictionarySizeBitsByLength[l]; |
| const int id = w.idx; |
| if (w.transform == 0) { |
| if (!IsMatch(w, &data[1], max_length - 1)) { |
| continue; |
| } |
| // Transforms " " + kIdentity + "" and "." + kIdentity + "" |
| AddMatch(id + (is_space ? 6 : 32) * n, l + 1, l, matches); |
| found_match = true; |
| if (l + 2 >= max_length) { |
| continue; |
| } |
| // Transforms " " + kIdentity + <suffix> and "." + kIdentity + <suffix> |
| const uint8_t* s = &data[l + 1]; |
| if (s[0] == ' ') { |
| AddMatch(id + (is_space ? 2 : 77) * n, l + 2, l, matches); |
| } else if (s[0] == '(') { |
| AddMatch(id + (is_space ? 89 : 67) * n, l + 2, l, matches); |
| } else if (is_space) { |
| if (s[0] == ',') { |
| AddMatch(id + 103 * n, l + 2, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + 33 * n, l + 3, l, matches); |
| } |
| } else if (s[0] == '.') { |
| AddMatch(id + 71 * n, l + 2, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + 52 * n, l + 3, l, matches); |
| } |
| } else if (s[0] == '=') { |
| if (s[1] == '"') { |
| AddMatch(id + 81 * n, l + 3, l, matches); |
| } else if (s[1] == '\'') { |
| AddMatch(id + 98 * n, l + 3, l, matches); |
| } |
| } |
| } |
| } else if (is_space) { |
| // Set t=0 for kUppercaseFirst and t=1 for kUppercaseAll transform. |
| const int t = w.transform - 10; |
| if (!IsMatch(w, &data[1], max_length - 1)) { |
| continue; |
| } |
| // Transforms " " + kUppercase{First,All} + "" |
| AddMatch(id + (t ? 85 : 30) * n, l + 1, l, matches); |
| found_match = true; |
| if (l + 2 >= max_length) { |
| continue; |
| } |
| // Transforms " " + kUppercase{First,All} + <suffix> |
| const uint8_t* s = &data[l + 1]; |
| if (s[0] == ' ') { |
| AddMatch(id + (t ? 83 : 15) * n, l + 2, l, matches); |
| } else if (s[0] == ',') { |
| if (t == 0) { |
| AddMatch(id + 109 * n, l + 2, l, matches); |
| } |
| if (s[1] == ' ') { |
| AddMatch(id + (t ? 111 : 65) * n, l + 3, l, matches); |
| } |
| } else if (s[0] == '.') { |
| AddMatch(id + (t ? 115 : 96) * n, l + 2, l, matches); |
| if (s[1] == ' ') { |
| AddMatch(id + (t ? 117 : 91) * n, l + 3, l, matches); |
| } |
| } else if (s[0] == '=') { |
| if (s[1] == '"') { |
| AddMatch(id + (t ? 110 : 118) * n, l + 3, l, matches); |
| } else if (s[1] == '\'') { |
| AddMatch(id + (t ? 119 : 120) * n, l + 3, l, matches); |
| } |
| } |
| } |
| } |
| } |
| if (max_length >= 6) { |
| // Transforms with prefixes "e ", "s ", ", " and "\xc2\xa0" |
| if ((data[1] == ' ' && |
| (data[0] == 'e' || data[0] == 's' || data[0] == ',')) || |
| (data[0] == 0xc2 && data[1] == 0xa0)) { |
| key = Hash(&data[2]); |
| bucket = kStaticDictionaryBuckets[key]; |
| int num = bucket & 0xff; |
| int offset = bucket >> 8; |
| for (int i = 0; i < num; ++i) { |
| const DictWord w = kStaticDictionaryWords[offset + i]; |
| const int l = w.len; |
| const int n = 1 << kBrotliDictionarySizeBitsByLength[l]; |
| const int id = w.idx; |
| if (w.transform == 0 && IsMatch(w, &data[2], max_length - 2)) { |
| if (data[0] == 0xc2) { |
| AddMatch(id + 102 * n, l + 2, l, matches); |
| found_match = true; |
| } else if (l + 2 < max_length && data[l + 2] == ' ') { |
| int t = data[0] == 'e' ? 18 : (data[0] == 's' ? 7 : 13); |
| AddMatch(id + t * n, l + 3, l, matches); |
| found_match = true; |
| } |
| } |
| } |
| } |
| } |
| if (max_length >= 9) { |
| // Transforms with prefixes " the " and ".com/" |
| if ((data[0] == ' ' && data[1] == 't' && data[2] == 'h' && |
| data[3] == 'e' && data[4] == ' ') || |
| (data[0] == '.' && data[1] == 'c' && data[2] == 'o' && |
| data[3] == 'm' && data[4] == '/')) { |
| key = Hash(&data[5]); |
| bucket = kStaticDictionaryBuckets[key]; |
| int num = bucket & 0xff; |
| int offset = bucket >> 8; |
| for (int i = 0; i < num; ++i) { |
| const DictWord w = kStaticDictionaryWords[offset + i]; |
| const int l = w.len; |
| const int n = 1 << kBrotliDictionarySizeBitsByLength[l]; |
| const int id = w.idx; |
| if (w.transform == 0 && IsMatch(w, &data[5], max_length - 5)) { |
| AddMatch(id + (data[0] == ' ' ? 41 : 72) * n, l + 5, l, matches); |
| found_match = true; |
| if (l + 5 < max_length) { |
| const uint8_t* s = &data[l + 5]; |
| if (data[0] == ' ') { |
| if (l + 8 < max_length && |
| s[0] == ' ' && s[1] == 'o' && s[2] == 'f' && s[3] == ' ') { |
| AddMatch(id + 62 * n, l + 9, l, matches); |
| if (l + 12 < max_length && |
| s[4] == 't' && s[5] == 'h' && s[6] == 'e' && s[7] == ' ') { |
| AddMatch(id + 73 * n, l + 13, l, matches); |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| return found_match; |
| } |
| |
| } // namespace brotli |