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      1 /*
      2  * Copyright (C) 2014 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 java.util.Locale;
     20 import java.util.concurrent.TimeUnit;
     21 
     22 import android.content.Context;
     23 import android.util.Log;
     24 
     25 /**
     26  * Cache for dictionary facilitators of multiple locales.
     27  * This class automatically creates and releases up to 3 facilitator instances using LRU policy.
     28  */
     29 public class DictionaryFacilitatorLruCache {
     30     private static final String TAG = "DictionaryFacilitatorLruCache";
     31     private static final int WAIT_FOR_LOADING_MAIN_DICT_IN_MILLISECONDS = 1000;
     32     private static final int MAX_RETRY_COUNT_FOR_WAITING_FOR_LOADING_DICT = 5;
     33 
     34     private final Context mContext;
     35     private final String mDictionaryNamePrefix;
     36     private final Object mLock = new Object();
     37     private final DictionaryFacilitator mDictionaryFacilitator;
     38     private boolean mUseContactsDictionary;
     39     private Locale mLocale;
     40 
     41     public DictionaryFacilitatorLruCache(final Context context, final String dictionaryNamePrefix) {
     42         mContext = context;
     43         mDictionaryNamePrefix = dictionaryNamePrefix;
     44         mDictionaryFacilitator = DictionaryFacilitatorProvider.getDictionaryFacilitator(
     45                 true /* isNeededForSpellChecking */);
     46     }
     47 
     48     private static void waitForLoadingMainDictionary(
     49             final DictionaryFacilitator dictionaryFacilitator) {
     50         for (int i = 0; i < MAX_RETRY_COUNT_FOR_WAITING_FOR_LOADING_DICT; i++) {
     51             try {
     52                 dictionaryFacilitator.waitForLoadingMainDictionaries(
     53                         WAIT_FOR_LOADING_MAIN_DICT_IN_MILLISECONDS, TimeUnit.MILLISECONDS);
     54                 return;
     55             } catch (final InterruptedException e) {
     56                 Log.i(TAG, "Interrupted during waiting for loading main dictionary.", e);
     57                 if (i < MAX_RETRY_COUNT_FOR_WAITING_FOR_LOADING_DICT - 1) {
     58                     Log.i(TAG, "Retry", e);
     59                 } else {
     60                     Log.w(TAG, "Give up retrying. Retried "
     61                             + MAX_RETRY_COUNT_FOR_WAITING_FOR_LOADING_DICT + " times.", e);
     62                 }
     63             }
     64         }
     65     }
     66 
     67     private void resetDictionariesForLocaleLocked() {
     68         // Nothing to do if the locale is null.  This would be the case before any get() calls.
     69         if (mLocale != null) {
     70           // Note: Given that personalized dictionaries are not used here; we can pass null account.
     71           mDictionaryFacilitator.resetDictionaries(mContext, mLocale,
     72               mUseContactsDictionary, false /* usePersonalizedDicts */,
     73               false /* forceReloadMainDictionary */, null /* account */,
     74               mDictionaryNamePrefix, null /* listener */);
     75         }
     76     }
     77 
     78     public void setUseContactsDictionary(final boolean useContactsDictionary) {
     79         synchronized (mLock) {
     80             if (mUseContactsDictionary == useContactsDictionary) {
     81                 // The value has not been changed.
     82                 return;
     83             }
     84             mUseContactsDictionary = useContactsDictionary;
     85             resetDictionariesForLocaleLocked();
     86             waitForLoadingMainDictionary(mDictionaryFacilitator);
     87         }
     88     }
     89 
     90     public DictionaryFacilitator get(final Locale locale) {
     91         synchronized (mLock) {
     92             if (!mDictionaryFacilitator.isForLocale(locale)) {
     93                 mLocale = locale;
     94                 resetDictionariesForLocaleLocked();
     95             }
     96             waitForLoadingMainDictionary(mDictionaryFacilitator);
     97             return mDictionaryFacilitator;
     98         }
     99     }
    100 
    101     public void closeDictionaries() {
    102         synchronized (mLock) {
    103             mDictionaryFacilitator.closeDictionaries();
    104         }
    105     }
    106 }
    107