1/*
2 * Copyright (C) 2013 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
17package com.android.inputmethod.latin.makedict;
18
19import com.android.inputmethod.annotations.UsedForTesting;
20import com.android.inputmethod.latin.BinaryDictionary;
21import com.android.inputmethod.latin.utils.FileUtils;
22
23import java.io.File;
24import java.io.FileNotFoundException;
25import java.io.IOException;
26import java.util.ArrayList;
27
28/**
29 * An implementation of binary dictionary decoder for version 4 binary dictionary.
30 */
31@UsedForTesting
32public class Ver4DictDecoder extends AbstractDictDecoder {
33    final File mDictDirectory;
34
35    @UsedForTesting
36    /* package */ Ver4DictDecoder(final File dictDirectory, final int factoryFlag) {
37        this(dictDirectory, null /* factory */);
38    }
39
40    @UsedForTesting
41    /* package */ Ver4DictDecoder(final File dictDirectory, final DictionaryBufferFactory factory) {
42        mDictDirectory = dictDirectory;
43
44    }
45
46    @Override
47    public DictionaryHeader readHeader() throws IOException, UnsupportedFormatException {
48        // dictType is not being used in dicttool. Passing an empty string.
49        final BinaryDictionary binaryDictionary= new BinaryDictionary(
50              mDictDirectory.getAbsolutePath(), 0 /* offset */, 0 /* length */,
51              true /* useFullEditDistance */, null /* locale */,
52              "" /* dictType */, true /* isUpdatable */);
53        final DictionaryHeader header = binaryDictionary.getHeader();
54        binaryDictionary.close();
55        if (header == null) {
56            throw new IOException("Cannot read the dictionary header.");
57        }
58        return header;
59    }
60
61    @Override
62    public FusionDictionary readDictionaryBinary(final boolean deleteDictIfBroken)
63            throws FileNotFoundException, IOException, UnsupportedFormatException {
64        // dictType is not being used in dicttool. Passing an empty string.
65        final BinaryDictionary binaryDictionary = new BinaryDictionary(
66              mDictDirectory.getAbsolutePath(), 0 /* offset */, 0 /* length */,
67              true /* useFullEditDistance */, null /* locale */,
68              "" /* dictType */, true /* isUpdatable */);
69        final DictionaryHeader header = readHeader();
70        final FusionDictionary fusionDict =
71                new FusionDictionary(new FusionDictionary.PtNodeArray(), header.mDictionaryOptions);
72        int token = 0;
73        final ArrayList<WordProperty> wordProperties = new ArrayList<>();
74        do {
75            final BinaryDictionary.GetNextWordPropertyResult result =
76                    binaryDictionary.getNextWordProperty(token);
77            final WordProperty wordProperty = result.mWordProperty;
78            if (wordProperty == null) {
79                binaryDictionary.close();
80                if (deleteDictIfBroken) {
81                    FileUtils.deleteRecursively(mDictDirectory);
82                }
83                return null;
84            }
85            wordProperties.add(wordProperty);
86            token = result.mNextToken;
87        } while (token != 0);
88
89        // Insert unigrams into the fusion dictionary.
90        for (final WordProperty wordProperty : wordProperties) {
91            if (wordProperty.mIsBlacklistEntry) {
92                fusionDict.addBlacklistEntry(wordProperty.mWord, wordProperty.mShortcutTargets,
93                        wordProperty.mIsNotAWord);
94            } else {
95                fusionDict.add(wordProperty.mWord, wordProperty.mProbabilityInfo,
96                        wordProperty.mShortcutTargets, wordProperty.mIsNotAWord);
97            }
98        }
99        // Insert bigrams into the fusion dictionary.
100        for (final WordProperty wordProperty : wordProperties) {
101            if (wordProperty.mBigrams == null) {
102                continue;
103            }
104            final String word0 = wordProperty.mWord;
105            for (final WeightedString bigram : wordProperty.mBigrams) {
106                fusionDict.setBigram(word0, bigram.mWord, bigram.mProbabilityInfo);
107            }
108        }
109        binaryDictionary.close();
110        return fusionDict;
111    }
112}
113