Home | History | Annotate | Download | only in latin 
      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;
     18 
     19 import com.android.inputmethod.keyboard.ProximityInfo;
     20 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
     21 
     22 import java.util.ArrayList;
     23 import java.util.Locale;
     24 import java.util.concurrent.locks.ReentrantReadWriteLock;
     25 
     26 /**
     27  * This class provides binary dictionary reading operations with locking. An instance of this class
     28  * can be used by multiple threads. Note that different session IDs must be used when multiple
     29  * threads get suggestions using this class.
     30  */
     31 public final class ReadOnlyBinaryDictionary extends Dictionary {
     32     /**
     33      * A lock for accessing binary dictionary. Only closing binary dictionary is the operation
     34      * that change the state of dictionary.
     35      */
     36     private final ReentrantReadWriteLock mLock = new ReentrantReadWriteLock();
     37 
     38     private final BinaryDictionary mBinaryDictionary;
     39 
     40     public ReadOnlyBinaryDictionary(final String filename, final long offset, final long length,
     41             final boolean useFullEditDistance, final Locale locale, final String dictType) {
     42         super(dictType);
     43         mBinaryDictionary = new BinaryDictionary(filename, offset, length, useFullEditDistance,
     44                 locale, dictType, false /* isUpdatable */);
     45     }
     46 
     47     public boolean isValidDictionary() {
     48         return mBinaryDictionary.isValidDictionary();
     49     }
     50 
     51     @Override
     52     public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
     53             final String prevWord, final ProximityInfo proximityInfo,
     54             final boolean blockOffensiveWords, final int[] additionalFeaturesOptions) {
     55         return getSuggestionsWithSessionId(composer, prevWord, proximityInfo, blockOffensiveWords,
     56                 additionalFeaturesOptions, 0 /* sessionId */);
     57     }
     58 
     59     @Override
     60     public ArrayList<SuggestedWordInfo> getSuggestionsWithSessionId(final WordComposer composer,
     61             final String prevWord, final ProximityInfo proximityInfo,
     62             final boolean blockOffensiveWords, final int[] additionalFeaturesOptions,
     63             final int sessionId) {
     64         if (mLock.readLock().tryLock()) {
     65             try {
     66                 return mBinaryDictionary.getSuggestions(composer, prevWord, proximityInfo,
     67                         blockOffensiveWords, additionalFeaturesOptions);
     68             } finally {
     69                 mLock.readLock().unlock();
     70             }
     71         }
     72         return null;
     73     }
     74 
     75     @Override
     76     public boolean isValidWord(final String word) {
     77         if (mLock.readLock().tryLock()) {
     78             try {
     79                 return mBinaryDictionary.isValidWord(word);
     80             } finally {
     81                 mLock.readLock().unlock();
     82             }
     83         }
     84         return false;
     85     }
     86 
     87     @Override
     88     public boolean shouldAutoCommit(final SuggestedWordInfo candidate) {
     89         if (mLock.readLock().tryLock()) {
     90             try {
     91                 return mBinaryDictionary.shouldAutoCommit(candidate);
     92             } finally {
     93                 mLock.readLock().unlock();
     94             }
     95         }
     96         return false;
     97     }
     98 
     99     @Override
    100     public int getFrequency(final String word) {
    101         if (mLock.readLock().tryLock()) {
    102             try {
    103                 return mBinaryDictionary.getFrequency(word);
    104             } finally {
    105                 mLock.readLock().unlock();
    106             }
    107         }
    108         return NOT_A_PROBABILITY;
    109     }
    110 
    111     @Override
    112     public void close() {
    113         mLock.writeLock().lock();
    114         try {
    115             mBinaryDictionary.close();
    116         } finally {
    117             mLock.writeLock().unlock();
    118         }
    119     }
    120 }
    121