| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * 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. |
| */ |
| |
| #include <vector> |
| #include <memory> |
| #include <algorithm> |
| #include <string> |
| #include <unicode/uchar.h> |
| |
| // HACK: for reading pattern file |
| #include <fcntl.h> |
| |
| #define LOG_TAG "Minikin" |
| #include "utils/Log.h" |
| |
| #include "minikin/Hyphenator.h" |
| |
| using std::vector; |
| |
| namespace android { |
| |
| static const uint16_t CHAR_SOFT_HYPHEN = 0x00AD; |
| |
| // The following are structs that correspond to tables inside the hyb file format |
| |
| struct AlphabetTable0 { |
| uint32_t version; |
| uint32_t min_codepoint; |
| uint32_t max_codepoint; |
| uint8_t data[1]; // actually flexible array, size is known at runtime |
| }; |
| |
| struct AlphabetTable1 { |
| uint32_t version; |
| uint32_t n_entries; |
| uint32_t data[1]; // actually flexible array, size is known at runtime |
| |
| static uint32_t codepoint(uint32_t entry) { return entry >> 11; } |
| static uint32_t value(uint32_t entry) { return entry & 0x7ff; } |
| }; |
| |
| struct Trie { |
| uint32_t version; |
| uint32_t char_mask; |
| uint32_t link_shift; |
| uint32_t link_mask; |
| uint32_t pattern_shift; |
| uint32_t n_entries; |
| uint32_t data[1]; // actually flexible array, size is known at runtime |
| }; |
| |
| struct Pattern { |
| uint32_t version; |
| uint32_t n_entries; |
| uint32_t pattern_offset; |
| uint32_t pattern_size; |
| uint32_t data[1]; // actually flexible array, size is known at runtime |
| |
| // accessors |
| static uint32_t len(uint32_t entry) { return entry >> 26; } |
| static uint32_t shift(uint32_t entry) { return (entry >> 20) & 0x3f; } |
| const uint8_t* buf(uint32_t entry) const { |
| return reinterpret_cast<const uint8_t*>(this) + pattern_offset + (entry & 0xfffff); |
| } |
| }; |
| |
| struct Header { |
| uint32_t magic; |
| uint32_t version; |
| uint32_t alphabet_offset; |
| uint32_t trie_offset; |
| uint32_t pattern_offset; |
| uint32_t file_size; |
| |
| // accessors |
| const uint8_t* bytes() const { return reinterpret_cast<const uint8_t*>(this); } |
| uint32_t alphabetVersion() const { |
| return *reinterpret_cast<const uint32_t*>(bytes() + alphabet_offset); |
| } |
| const AlphabetTable0* alphabetTable0() const { |
| return reinterpret_cast<const AlphabetTable0*>(bytes() + alphabet_offset); |
| } |
| const AlphabetTable1* alphabetTable1() const { |
| return reinterpret_cast<const AlphabetTable1*>(bytes() + alphabet_offset); |
| } |
| const Trie* trieTable() const { |
| return reinterpret_cast<const Trie*>(bytes() + trie_offset); |
| } |
| const Pattern* patternTable() const { |
| return reinterpret_cast<const Pattern*>(bytes() + pattern_offset); |
| } |
| }; |
| |
| Hyphenator* Hyphenator::loadBinary(const uint8_t* patternData) { |
| Hyphenator* result = new Hyphenator; |
| result->patternData = patternData; |
| return result; |
| } |
| |
| void Hyphenator::hyphenate(vector<uint8_t>* result, const uint16_t* word, size_t len) { |
| result->clear(); |
| result->resize(len); |
| const size_t paddedLen = len + 2; // start and stop code each count for 1 |
| if (patternData != nullptr && |
| (int)len >= MIN_PREFIX + MIN_SUFFIX && paddedLen <= MAX_HYPHENATED_SIZE) { |
| uint16_t alpha_codes[MAX_HYPHENATED_SIZE]; |
| if (alphabetLookup(alpha_codes, word, len)) { |
| hyphenateFromCodes(result->data(), alpha_codes, paddedLen); |
| return; |
| } |
| // TODO: try NFC normalization |
| // TODO: handle non-BMP Unicode (requires remapping of offsets) |
| } |
| hyphenateSoft(result->data(), word, len); |
| } |
| |
| // If any soft hyphen is present in the word, use soft hyphens to decide hyphenation, |
| // as recommended in UAX #14 (Use of Soft Hyphen) |
| void Hyphenator::hyphenateSoft(uint8_t* result, const uint16_t* word, size_t len) { |
| result[0] = 0; |
| for (size_t i = 1; i < len; i++) { |
| result[i] = word[i - 1] == CHAR_SOFT_HYPHEN; |
| } |
| } |
| |
| bool Hyphenator::alphabetLookup(uint16_t* alpha_codes, const uint16_t* word, size_t len) { |
| const Header* header = getHeader(); |
| // TODO: check header magic |
| uint32_t alphabetVersion = header->alphabetVersion(); |
| if (alphabetVersion == 0) { |
| const AlphabetTable0* alphabet = header->alphabetTable0(); |
| uint32_t min_codepoint = alphabet->min_codepoint; |
| uint32_t max_codepoint = alphabet->max_codepoint; |
| alpha_codes[0] = 0; // word start |
| for (size_t i = 0; i < len; i++) { |
| uint16_t c = word[i]; |
| if (c < min_codepoint || c >= max_codepoint) { |
| return false; |
| } |
| uint8_t code = alphabet->data[c - min_codepoint]; |
| if (code == 0) { |
| return false; |
| } |
| alpha_codes[i + 1] = code; |
| } |
| alpha_codes[len + 1] = 0; // word termination |
| return true; |
| } else if (alphabetVersion == 1) { |
| const AlphabetTable1* alphabet = header->alphabetTable1(); |
| size_t n_entries = alphabet->n_entries; |
| const uint32_t* begin = alphabet->data; |
| const uint32_t* end = begin + n_entries; |
| alpha_codes[0] = 0; |
| for (size_t i = 0; i < len; i++) { |
| uint16_t c = word[i]; |
| auto p = std::lower_bound(begin, end, c << 11); |
| if (p == end) { |
| return false; |
| } |
| uint32_t entry = *p; |
| if (AlphabetTable1::codepoint(entry) != c) { |
| return false; |
| } |
| alpha_codes[i + 1] = AlphabetTable1::value(entry); |
| } |
| alpha_codes[len + 1] = 0; |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Internal implementation, after conversion to codes. All case folding and normalization |
| * has been done by now, and all characters have been found in the alphabet. |
| * Note: len here is the padded length including 0 codes at start and end. |
| **/ |
| void Hyphenator::hyphenateFromCodes(uint8_t* result, const uint16_t* codes, size_t len) { |
| const Header* header = getHeader(); |
| const Trie* trie = header->trieTable(); |
| const Pattern* pattern = header->patternTable(); |
| uint32_t char_mask = trie->char_mask; |
| uint32_t link_shift = trie->link_shift; |
| uint32_t link_mask = trie->link_mask; |
| uint32_t pattern_shift = trie->pattern_shift; |
| size_t maxOffset = len - MIN_SUFFIX - 1; |
| for (size_t i = 0; i < len - 1; i++) { |
| uint32_t node = 0; // index into Trie table |
| for (size_t j = i; j < len; j++) { |
| uint16_t c = codes[j]; |
| uint32_t entry = trie->data[node + c]; |
| if ((entry & char_mask) == c) { |
| node = (entry & link_mask) >> link_shift; |
| } else { |
| break; |
| } |
| uint32_t pat_ix = trie->data[node] >> pattern_shift; |
| // pat_ix contains a 3-tuple of length, shift (number of trailing zeros), and an offset |
| // into the buf pool. This is the pattern for the substring (i..j) we just matched, |
| // which we combine (via point-wise max) into the result vector. |
| if (pat_ix != 0) { |
| uint32_t pat_entry = pattern->data[pat_ix]; |
| int pat_len = Pattern::len(pat_entry); |
| int pat_shift = Pattern::shift(pat_entry); |
| const uint8_t* pat_buf = pattern->buf(pat_entry); |
| int offset = j + 1 - (pat_len + pat_shift); |
| // offset is the index within result that lines up with the start of pat_buf |
| int start = std::max(MIN_PREFIX - offset, 0); |
| int end = std::min(pat_len, (int)maxOffset - offset); |
| for (int k = start; k < end; k++) { |
| result[offset + k] = std::max(result[offset + k], pat_buf[k]); |
| } |
| } |
| } |
| } |
| // Since the above calculation does not modify values outside |
| // [MIN_PREFIX, len - MIN_SUFFIX], they are left as 0. |
| for (size_t i = MIN_PREFIX; i < maxOffset; i++) { |
| result[i] &= 1; |
| } |
| } |
| |
| } // namespace android |