1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * 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, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17 package com.android.inputmethod.latin; 18 19 import android.content.Context; 20 import android.text.TextUtils; 21 22 import com.android.inputmethod.keyboard.ProximityInfo; 23 24 import java.util.Arrays; 25 import java.util.Locale; 26 27 /** 28 * Implements a static, compacted, binary dictionary of standard words. 29 */ 30 public class BinaryDictionary extends Dictionary { 31 32 public static final String DICTIONARY_PACK_AUTHORITY = 33 "com.android.inputmethod.latin.dictionarypack"; 34 35 /** 36 * There is a difference between what java and native code can handle. 37 * This value should only be used in BinaryDictionary.java 38 * It is necessary to keep it at this value because some languages e.g. German have 39 * really long words. 40 */ 41 public static final int MAX_WORD_LENGTH = 48; 42 public static final int MAX_WORDS = 18; 43 44 private static final String TAG = "BinaryDictionary"; 45 private static final int MAX_BIGRAMS = 60; 46 47 private static final int TYPED_LETTER_MULTIPLIER = 2; 48 49 private int mDicTypeId; 50 private long mNativeDict; 51 private final int[] mInputCodes = new int[MAX_WORD_LENGTH]; 52 private final char[] mOutputChars = new char[MAX_WORD_LENGTH * MAX_WORDS]; 53 private final char[] mOutputChars_bigrams = new char[MAX_WORD_LENGTH * MAX_BIGRAMS]; 54 private final int[] mScores = new int[MAX_WORDS]; 55 private final int[] mBigramScores = new int[MAX_BIGRAMS]; 56 57 private final boolean mUseFullEditDistance; 58 59 /** 60 * Constructor for the binary dictionary. This is supposed to be called from the 61 * dictionary factory. 62 * All implementations should pass null into flagArray, except for testing purposes. 63 * @param context the context to access the environment from. 64 * @param filename the name of the file to read through native code. 65 * @param offset the offset of the dictionary data within the file. 66 * @param length the length of the binary data. 67 * @param useFullEditDistance whether to use the full edit distance in suggestions 68 */ 69 public BinaryDictionary(final Context context, 70 final String filename, final long offset, final long length, 71 final boolean useFullEditDistance, final Locale locale) { 72 // Note: at the moment a binary dictionary is always of the "main" type. 73 // Initializing this here will help transitioning out of the scheme where 74 // the Suggest class knows everything about every single dictionary. 75 mDicTypeId = Suggest.DIC_MAIN; 76 mUseFullEditDistance = useFullEditDistance; 77 loadDictionary(filename, offset, length); 78 } 79 80 static { 81 JniUtils.loadNativeLibrary(); 82 } 83 84 private native long openNative(String sourceDir, long dictOffset, long dictSize, 85 int typedLetterMultiplier, int fullWordMultiplier, int maxWordLength, int maxWords); 86 private native void closeNative(long dict); 87 private native int getFrequencyNative(long dict, int[] word, int wordLength); 88 private native boolean isValidBigramNative(long dict, int[] word1, int[] word2); 89 private native int getSuggestionsNative(long dict, long proximityInfo, int[] xCoordinates, 90 int[] yCoordinates, int[] inputCodes, int codesSize, int[] prevWordForBigrams, 91 boolean useFullEditDistance, char[] outputChars, int[] scores); 92 private native int getBigramsNative(long dict, int[] prevWord, int prevWordLength, 93 int[] inputCodes, int inputCodesLength, char[] outputChars, int[] scores, 94 int maxWordLength, int maxBigrams); 95 private static native float calcNormalizedScoreNative( 96 char[] before, int beforeLength, char[] after, int afterLength, int score); 97 private static native int editDistanceNative( 98 char[] before, int beforeLength, char[] after, int afterLength); 99 100 private final void loadDictionary(String path, long startOffset, long length) { 101 mNativeDict = openNative(path, startOffset, length, 102 TYPED_LETTER_MULTIPLIER, FULL_WORD_SCORE_MULTIPLIER, MAX_WORD_LENGTH, MAX_WORDS); 103 } 104 105 @Override 106 public void getBigrams(final WordComposer codes, final CharSequence previousWord, 107 final WordCallback callback) { 108 if (mNativeDict == 0) return; 109 110 int[] codePoints = StringUtils.toCodePointArray(previousWord.toString()); 111 Arrays.fill(mOutputChars_bigrams, (char) 0); 112 Arrays.fill(mBigramScores, 0); 113 114 int codesSize = codes.size(); 115 Arrays.fill(mInputCodes, -1); 116 if (codesSize > 0) { 117 mInputCodes[0] = codes.getCodeAt(0); 118 } 119 120 int count = getBigramsNative(mNativeDict, codePoints, codePoints.length, mInputCodes, 121 codesSize, mOutputChars_bigrams, mBigramScores, MAX_WORD_LENGTH, MAX_BIGRAMS); 122 if (count > MAX_BIGRAMS) { 123 count = MAX_BIGRAMS; 124 } 125 126 for (int j = 0; j < count; ++j) { 127 if (codesSize > 0 && mBigramScores[j] < 1) break; 128 final int start = j * MAX_WORD_LENGTH; 129 int len = 0; 130 while (len < MAX_WORD_LENGTH && mOutputChars_bigrams[start + len] != 0) { 131 ++len; 132 } 133 if (len > 0) { 134 callback.addWord(mOutputChars_bigrams, start, len, mBigramScores[j], 135 mDicTypeId, Dictionary.BIGRAM); 136 } 137 } 138 } 139 140 // proximityInfo and/or prevWordForBigrams may not be null. 141 @Override 142 public void getWords(final WordComposer codes, final CharSequence prevWordForBigrams, 143 final WordCallback callback, final ProximityInfo proximityInfo) { 144 final int count = getSuggestions(codes, prevWordForBigrams, proximityInfo, mOutputChars, 145 mScores); 146 147 for (int j = 0; j < count; ++j) { 148 if (mScores[j] < 1) break; 149 final int start = j * MAX_WORD_LENGTH; 150 int len = 0; 151 while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) { 152 ++len; 153 } 154 if (len > 0) { 155 callback.addWord(mOutputChars, start, len, mScores[j], mDicTypeId, 156 Dictionary.UNIGRAM); 157 } 158 } 159 } 160 161 /* package for test */ boolean isValidDictionary() { 162 return mNativeDict != 0; 163 } 164 165 // proximityInfo may not be null. 166 /* package for test */ int getSuggestions(final WordComposer codes, 167 final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo, 168 char[] outputChars, int[] scores) { 169 if (!isValidDictionary()) return -1; 170 171 final int codesSize = codes.size(); 172 // Won't deal with really long words. 173 if (codesSize > MAX_WORD_LENGTH - 1) return -1; 174 175 Arrays.fill(mInputCodes, WordComposer.NOT_A_CODE); 176 for (int i = 0; i < codesSize; i++) { 177 mInputCodes[i] = codes.getCodeAt(i); 178 } 179 Arrays.fill(outputChars, (char) 0); 180 Arrays.fill(scores, 0); 181 182 final int[] prevWordCodePointArray = null == prevWordForBigrams 183 ? null : StringUtils.toCodePointArray(prevWordForBigrams.toString()); 184 185 // TODO: pass the previous word to native code 186 return getSuggestionsNative( 187 mNativeDict, proximityInfo.getNativeProximityInfo(), 188 codes.getXCoordinates(), codes.getYCoordinates(), mInputCodes, codesSize, 189 prevWordCodePointArray, mUseFullEditDistance, outputChars, scores); 190 } 191 192 public static float calcNormalizedScore(String before, String after, int score) { 193 return calcNormalizedScoreNative(before.toCharArray(), before.length(), 194 after.toCharArray(), after.length(), score); 195 } 196 197 public static int editDistance(String before, String after) { 198 return editDistanceNative( 199 before.toCharArray(), before.length(), after.toCharArray(), after.length()); 200 } 201 202 @Override 203 public boolean isValidWord(CharSequence word) { 204 return getFrequency(word) >= 0; 205 } 206 207 @Override 208 public int getFrequency(CharSequence word) { 209 if (word == null) return -1; 210 int[] chars = StringUtils.toCodePointArray(word.toString()); 211 return getFrequencyNative(mNativeDict, chars, chars.length); 212 } 213 214 // TODO: Add a batch process version (isValidBigramMultiple?) to avoid excessive numbers of jni 215 // calls when checking for changes in an entire dictionary. 216 public boolean isValidBigram(CharSequence word1, CharSequence word2) { 217 if (TextUtils.isEmpty(word1) || TextUtils.isEmpty(word2)) return false; 218 int[] chars1 = StringUtils.toCodePointArray(word1.toString()); 219 int[] chars2 = StringUtils.toCodePointArray(word2.toString()); 220 return isValidBigramNative(mNativeDict, chars1, chars2); 221 } 222 223 @Override 224 public synchronized void close() { 225 closeInternal(); 226 } 227 228 private void closeInternal() { 229 if (mNativeDict != 0) { 230 closeNative(mNativeDict); 231 mNativeDict = 0; 232 } 233 } 234 235 @Override 236 protected void finalize() throws Throwable { 237 try { 238 closeInternal(); 239 } finally { 240 super.finalize(); 241 } 242 } 243 } 244