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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.personalization;
     18 
     19 import android.content.Context;
     20 
     21 import com.android.inputmethod.latin.BinaryDictionary;
     22 import com.android.inputmethod.latin.NgramContext;
     23 import com.android.inputmethod.latin.NgramContext.WordInfo;
     24 import com.android.inputmethod.latin.common.FileUtils;
     25 
     26 import java.io.File;
     27 import java.io.FilenameFilter;
     28 import java.util.ArrayList;
     29 import java.util.HashSet;
     30 import java.util.List;
     31 import java.util.Locale;
     32 import java.util.Random;
     33 
     34 /**
     35  * Utility class for helping while running tests involving {@link UserHistoryDictionary}.
     36  */
     37 public class UserHistoryDictionaryTestsHelper {
     38 
     39     /**
     40      * Locale prefix for generating dummy locales for tests.
     41      */
     42     public static final String TEST_LOCALE_PREFIX = "test-";
     43 
     44     /**
     45      * Characters for generating random words.
     46      */
     47     private static final String[] CHARACTERS = {
     48         "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",
     49         "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"
     50     };
     51 
     52     /**
     53      * Remove all the test dictionary files created for the given locale.
     54      */
     55     public static void removeAllTestDictFiles(final String filter, final Context context) {
     56         final FilenameFilter filenameFilter = new FilenameFilter() {
     57             @Override
     58             public boolean accept(final File dir, final String filename) {
     59                 return filename.startsWith(UserHistoryDictionary.NAME + "." + filter);
     60             }
     61         };
     62         FileUtils.deleteFilteredFiles(context.getFilesDir(), filenameFilter);
     63     }
     64 
     65     /**
     66      * Generates and writes random words to dictionary. Caller can be assured
     67      * that the write tasks would be finished; and its success would be reflected
     68      * in the returned boolean.
     69      *
     70      * @param dict {@link UserHistoryDictionary} to which words should be added.
     71      * @param numberOfWords number of words to be added.
     72      * @param random helps generate random words.
     73      * @param checkContents if true, checks whether written words are actually in the dictionary.
     74      * @param currentTime timestamp that would be used for adding the words.
     75      * @returns true if all words have been written to dictionary successfully.
     76      */
     77     public static boolean addAndWriteRandomWords(final UserHistoryDictionary dict,
     78             final int numberOfWords, final Random random, final boolean checkContents,
     79             final int currentTime) {
     80         final List<String> words = generateWords(numberOfWords, random);
     81         // Add random words to the user history dictionary.
     82         addWordsToDictionary(dict, words, currentTime);
     83         boolean success = true;
     84         if (checkContents) {
     85             dict.waitAllTasksForTests();
     86             for (int i = 0; i < numberOfWords; ++i) {
     87                 final String word = words.get(i);
     88                 if (!dict.isInDictionary(word)) {
     89                     success = false;
     90                     break;
     91                 }
     92             }
     93         }
     94         // write to file.
     95         dict.close();
     96         dict.waitAllTasksForTests();
     97         return success;
     98     }
     99 
    100     private static void addWordsToDictionary(final UserHistoryDictionary dict,
    101             final List<String> words, final int timestamp) {
    102         NgramContext ngramContext = NgramContext.getEmptyPrevWordsContext(
    103                 BinaryDictionary.MAX_PREV_WORD_COUNT_FOR_N_GRAM);
    104         for (final String word : words) {
    105             UserHistoryDictionary.addToDictionary(dict, ngramContext, word, true, timestamp);
    106             ngramContext = ngramContext.getNextNgramContext(new WordInfo(word));
    107         }
    108     }
    109 
    110     /**
    111      * Creates unique test locale for using within tests.
    112      */
    113     public static Locale getDummyLocale(final String name) {
    114         return new Locale(TEST_LOCALE_PREFIX + name + System.currentTimeMillis());
    115     }
    116 
    117     /**
    118      * Generates random words.
    119      *
    120      * @param numberOfWords number of words to generate.
    121      * @param random salt used for generating random words.
    122      */
    123     public static List<String> generateWords(final int numberOfWords, final Random random) {
    124         final HashSet<String> wordSet = new HashSet<>();
    125         while (wordSet.size() < numberOfWords) {
    126             wordSet.add(generateWord(random.nextInt()));
    127         }
    128         return new ArrayList<>(wordSet);
    129     }
    130 
    131     /**
    132      * Generates a random word.
    133      */
    134     private static String generateWord(final int value) {
    135         final int lengthOfChars = CHARACTERS.length;
    136         final StringBuilder builder = new StringBuilder();
    137         long lvalue = Math.abs((long)value);
    138         while (lvalue > 0) {
    139             builder.append(CHARACTERS[(int)(lvalue % lengthOfChars)]);
    140             lvalue /= lengthOfChars;
    141         }
    142         return builder.toString();
    143     }
    144 }
    145