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      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 
     17 package com.android.inputmethod.latin.personalization;
     18 
     19 import android.content.Context;
     20 
     21 import com.android.inputmethod.latin.Dictionary;
     22 import com.android.inputmethod.latin.ExpandableBinaryDictionary;
     23 import com.android.inputmethod.latin.makedict.DictionaryHeader;
     24 
     25 import java.io.File;
     26 import java.util.Locale;
     27 import 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  */
     33 public 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