DecayingExpandableBinaryDictionaryBase.java revision 1910392eeddf2c9f4c1d34925e64f8d8772e7dc4 
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.personalization;
18
19import android.content.Context;
20
21import com.android.inputmethod.latin.Dictionary;
22import com.android.inputmethod.latin.ExpandableBinaryDictionary;
23import com.android.inputmethod.latin.makedict.DictionaryHeader;
24
25import java.io.File;
26import java.util.Locale;
27import java.util.Map;
28
29/**
30 * This class is a base class of a dictionary that supports decaying for the personalized language
31 * model.
32 */
33public abstract class DecayingExpandableBinaryDictionaryBase extends ExpandableBinaryDictionary {
34    private static final boolean DBG_DUMP_ON_CLOSE = false;
35
36    /** Any pair being typed or picked */
37    public static final int FREQUENCY_FOR_TYPED = 2;
38
39    public static final int FREQUENCY_FOR_WORDS_IN_DICTS = FREQUENCY_FOR_TYPED;
40    public static final int FREQUENCY_FOR_WORDS_NOT_IN_DICTS = Dictionary.NOT_A_PROBABILITY;
41
42    /** The locale for this dictionary. */
43    public final Locale mLocale;
44
45    protected DecayingExpandableBinaryDictionaryBase(final Context context,
46            final String dictName, final Locale locale, final String dictionaryType,
47            final File dictFile) {
48        super(context, dictName, locale, dictionaryType, dictFile);
49        mLocale = locale;
50        if (mLocale != null && mLocale.toString().length() > 1) {
51            reloadDictionaryIfRequired();
52        }
53    }
54
55    @Override
56    public void close() {
57        if (DBG_DUMP_ON_CLOSE) {
58            dumpAllWordsForDebug();
59        }
60        // Flush pending writes.
61        asyncFlushBinaryDictionary();
62        super.close();
63    }
64
65    @Override
66    protected Map<String, String> getHeaderAttributeMap() {
67        final Map<String, String> attributeMap = super.getHeaderAttributeMap();
68        attributeMap.put(DictionaryHeader.USES_FORGETTING_CURVE_KEY,
69                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
70        attributeMap.put(DictionaryHeader.HAS_HISTORICAL_INFO_KEY,
71                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
72        return attributeMap;
73    }
74
75    @Override
76    protected void loadInitialContentsLocked() {
77        // No initial contents.
78    }
79
80    /* package */ void runGCIfRequired() {
81        runGCIfRequired(false /* mindsBlockByGC */);
82    }
83
84    @Override
85    public boolean isValidWord(final String word) {
86        // Strings out of this dictionary should not be considered existing words.
87        return false;
88    }
89}
90