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 android.util.Log;

import com.android.inputmethod.annotations.UsedForTesting;
import com.android.inputmethod.latin.BinaryDictionary.LanguageModelParam;
import com.android.inputmethod.latin.Constants;
import com.android.inputmethod.latin.Dictionary;
import com.android.inputmethod.latin.ExpandableBinaryDictionary;
import com.android.inputmethod.latin.makedict.DictDecoder;
import com.android.inputmethod.latin.makedict.FormatSpec;
import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
import com.android.inputmethod.latin.utils.CollectionUtils;
import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils;
import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils.OnAddWordListener;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * 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();
    public static final boolean DBG_SAVE_RESTORE = false;
    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;

    public static final int REQUIRED_BINARY_DICTIONARY_VERSION = 4;

    /** Locale for which this user history dictionary is storing words */
    private final Locale mLocale;

    private final String mFileName;

    private final ArrayList<PersonalizationDictionaryUpdateSession> mSessions =
            CollectionUtils.newArrayList();

    // Should always be false except when we use this class for test
    @UsedForTesting boolean mIsTest = false;

    /* package */ DecayingExpandableBinaryDictionaryBase(final Context context,