LatinIME/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java

/*
 * Copyright (C) 2013 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.
 */

package com.android.inputmethod.latin.personalization;

import android.content.Context;

import com.android.inputmethod.latin.Dictionary;
import com.android.inputmethod.latin.ExpandableBinaryDictionary;
import com.android.inputmethod.latin.makedict.DictionaryHeader;

import java.io.File;
import java.util.Locale;
import java.util.Map;

/**
 * This class is a base class of a dictionary that supports decaying for the personalized language
 * model.
 */
public abstract class DecayingExpandableBinaryDictionaryBase extends ExpandableBinaryDictionary {
    private static final String TAG = DecayingExpandableBinaryDictionaryBase.class.getSimpleName();
    private static final boolean DBG_DUMP_ON_CLOSE = false;

    /** Any pair being typed or picked */
    public static final int FREQUENCY_FOR_TYPED = 2;

    public static final int FREQUENCY_FOR_WORDS_IN_DICTS = FREQUENCY_FOR_TYPED;
    public static final int FREQUENCY_FOR_WORDS_NOT_IN_DICTS = Dictionary.NOT_A_PROBABILITY;

    /** The locale for this dictionary. */
    public final Locale mLocale;

    protected DecayingExpandableBinaryDictionaryBase(final Context context,
            final String dictName, final Locale locale, final String dictionaryType,
            final File dictFile) {
        super(context, dictName, locale, dictionaryType, dictFile);
        mLocale = locale;
        if (mLocale != null && mLocale.toString().length() > 1) {
            reloadDictionaryIfRequired();
        }
    }

    @Override
    public void close() {
        if (DBG_DUMP_ON_CLOSE) {
            dumpAllWordsForDebug();
        }
        // Flush pending writes.
        asyncFlushBinaryDictionary();
        super.close();
    }

    @Override
    protected Map<String, String> getHeaderAttributeMap() {
        final Map<String, String> attributeMap = super.getHeaderAttributeMap();
        attributeMap.put(DictionaryHeader.USES_FORGETTING_CURVE_KEY,
                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
        attributeMap.put(DictionaryHeader.HAS_HISTORICAL_INFO_KEY,
                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
        return attributeMap;
    }

    @Override
    protected boolean haveContentsChanged() {
        return false;
    }

    @Override
    protected void loadInitialContentsLocked() {
        // No initial contents.
    }

    /* package */ void runGCIfRequired() {
        runGCIfRequired(false /* mindsBlockByGC */);
    }
}