1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef LATINIME_DICT_TOOLKIT_UTF8_UTILS_H
18#define LATINIME_DICT_TOOLKIT_UTF8_UTILS_H
19
20#include <cstdint>
21#include <string>
22#include <vector>
23
24#include "dict_toolkit_defines.h"
25#include "utils/int_array_view.h"
26
27namespace latinime {
28namespace dicttoolkit {
29
30class Utf8Utils {
31public:
32    static std::vector<int> getCodePoints(const std::string &utf8Str);
33    static std::string getUtf8String(const CodePointArrayView codePoints);
34
35private:
36    DISALLOW_IMPLICIT_CONSTRUCTORS(Utf8Utils);
37
38    // Values indexed by sequence size.
39    static const size_t MAX_SEQUENCE_SIZE_FOR_A_CODE_POINT;
40    static const uint8_t FIRST_BYTE_MARKER_MASKS[];
41    static const uint8_t FIRST_BYTE_MARKERS[];
42    static const uint8_t FIRST_BYTE_CODE_POINT_BITS_MASKS[];
43    static const int MAX_ENCODED_CODE_POINT_VALUES[];
44
45    static const uint8_t TRAILING_BYTE_CODE_POINT_BITS_MASK;
46    static const uint8_t TRAILING_BYTE_MARKER;
47    static const size_t CODE_POINT_BIT_COUNT_IN_TRAILING_BYTE;
48
49    static int getSequenceSizeByCheckingFirstByte(const uint8_t firstByte);
50    static int maskFirstByte(const uint8_t firstByte, const int encodeSize);
51    static int maskTrailingByte(const uint8_t secondOrLaterByte);
52    static int getSequenceSizeToEncodeCodePoint(const int codePoint);
53};
54} // namespace dicttoolkit
55} // namespace latinime
56#endif // LATINIME_DICT_TOOLKIT_UTF8_UTILS_H
57