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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.annotations.ExternallyReferenced;
     22 import com.android.inputmethod.annotations.UsedForTesting;
     23 import com.android.inputmethod.latin.BinaryDictionary;
     24 import com.android.inputmethod.latin.Dictionary;
     25 import com.android.inputmethod.latin.ExpandableBinaryDictionary;
     26 import com.android.inputmethod.latin.NgramContext;
     27 import com.android.inputmethod.latin.define.DecoderSpecificConstants;
     28 import com.android.inputmethod.latin.define.ProductionFlags;
     29 import com.android.inputmethod.latin.makedict.DictionaryHeader;
     30 
     31 import java.io.File;
     32 import java.util.Locale;
     33 import java.util.Map;
     34 
     35 import javax.annotation.Nonnull;
     36 import javax.annotation.Nullable;
     37 
     38 /**
     39  * Locally gathers statistics about the words user types and various other signals like
     40  * auto-correction cancellation or manual picks. This allows the keyboard to adapt to the
     41  * typist over time.
     42  */
     43 public class UserHistoryDictionary extends ExpandableBinaryDictionary {
     44     static final String NAME = UserHistoryDictionary.class.getSimpleName();
     45 
     46     // TODO: Make this constructor private
     47     UserHistoryDictionary(final Context context, final Locale locale,
     48             @Nullable final String account) {
     49         super(context, getUserHistoryDictName(NAME, locale, null /* dictFile */, account), locale, Dictionary.TYPE_USER_HISTORY, null);
     50         if (mLocale != null && mLocale.toString().length() > 1) {
     51             reloadDictionaryIfRequired();
     52         }
     53     }
     54 
     55     /**
     56      * @returns the name of the {@link UserHistoryDictionary}.
     57      */
     58     @UsedForTesting
     59     static String getUserHistoryDictName(final String name, final Locale locale,
     60             @Nullable final File dictFile, @Nullable final String account) {
     61         if (!ProductionFlags.ENABLE_PER_ACCOUNT_USER_HISTORY_DICTIONARY) {
     62             return getDictName(name, locale, dictFile);
     63         }
     64         return getUserHistoryDictNamePerAccount(name, locale, dictFile, account);
     65     }
     66 
     67     /**
     68      * Uses the currently signed in account to determine the dictionary name.
     69      */
     70     private static String getUserHistoryDictNamePerAccount(final String name, final Locale locale,
     71             @Nullable final File dictFile, @Nullable final String account) {
     72         if (dictFile != null) {
     73             return dictFile.getName();
     74         }
     75         String dictName = name + "." + locale.toString();
     76         if (account != null) {
     77             dictName += "." + account;
     78         }
     79         return dictName;
     80     }
     81 
     82     // Note: This method is called by {@link DictionaryFacilitator} using Java reflection.
     83     @SuppressWarnings("unused")
     84     @ExternallyReferenced
     85     public static UserHistoryDictionary getDictionary(final Context context, final Locale locale,
     86             final File dictFile, final String dictNamePrefix, @Nullable final String account) {
     87         return PersonalizationHelper.getUserHistoryDictionary(context, locale, account);
     88     }
     89 
     90     /**
     91      * Add a word to the user history dictionary.
     92      *
     93      * @param userHistoryDictionary the user history dictionary
     94      * @param ngramContext the n-gram context
     95      * @param word the word the user inputted
     96      * @param isValid whether the word is valid or not
     97      * @param timestamp the timestamp when the word has been inputted
     98      */
     99     public static void addToDictionary(final ExpandableBinaryDictionary userHistoryDictionary,
    100             @Nonnull final NgramContext ngramContext, final String word, final boolean isValid,
    101             final int timestamp) {
    102         if (word.length() > BinaryDictionary.DICTIONARY_MAX_WORD_LENGTH) {
    103             return;
    104         }
    105         userHistoryDictionary.updateEntriesForWord(ngramContext, word,
    106                 isValid, 1 /* count */, timestamp);
    107     }
    108 
    109     @Override
    110     public void close() {
    111         // Flush pending writes.
    112         asyncFlushBinaryDictionary();
    113         super.close();
    114     }
    115 
    116     @Override
    117     protected Map<String, String> getHeaderAttributeMap() {
    118         final Map<String, String> attributeMap = super.getHeaderAttributeMap();
    119         attributeMap.put(DictionaryHeader.USES_FORGETTING_CURVE_KEY,
    120                 DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
    121         attributeMap.put(DictionaryHeader.HAS_HISTORICAL_INFO_KEY,
    122                 DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
    123         return attributeMap;
    124     }
    125 
    126     @Override
    127     protected void loadInitialContentsLocked() {
    128         // No initial contents.
    129     }
    130 
    131     @Override
    132     public boolean isValidWord(final String word) {
    133         // Strings out of this dictionary should not be considered existing words.
    134         return false;
    135     }
    136 }
    137