BinaryDictionary.java revision 24eec0fa680f97e64d1fa0df754acbad95ed9a76
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 17package com.android.inputmethod.latin; 18 19import android.content.Context; 20import android.text.TextUtils; 21 22import com.android.inputmethod.keyboard.ProximityInfo; 23import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo; 24 25import java.util.ArrayList; 26import java.util.Arrays; 27import java.util.Locale; 28 29/** 30 * Implements a static, compacted, binary dictionary of standard words. 31 */ 32public class BinaryDictionary extends Dictionary { 33 34 public static final String DICTIONARY_PACK_AUTHORITY = 35 "com.android.inputmethod.latin.dictionarypack"; 36 37 /** 38 * There is a difference between what java and native code can handle. 39 * This value should only be used in BinaryDictionary.java 40 * It is necessary to keep it at this value because some languages e.g. German have 41 * really long words. 42 */ 43 public static final int MAX_WORD_LENGTH = 48; 44 public static final int MAX_WORDS = 18; 45 public static final int MAX_SPACES = 16; 46 47 private static final String TAG = "BinaryDictionary"; 48 private static final int MAX_BIGRAMS = 60; 49 50 private static final int TYPED_LETTER_MULTIPLIER = 2; 51 52 private long mNativeDict; 53 private final int[] mInputCodes = new int[MAX_WORD_LENGTH]; 54 private final char[] mOutputChars = new char[MAX_WORD_LENGTH * MAX_WORDS]; 55 private final char[] mOutputChars_bigrams = new char[MAX_WORD_LENGTH * MAX_BIGRAMS]; 56 private final int[] mSpaceIndices = new int[MAX_SPACES]; 57 private final int[] mScores = new int[MAX_WORDS]; 58 private final int[] mBigramScores = new int[MAX_BIGRAMS]; 59 60 private final boolean mUseFullEditDistance; 61 62 /** 63 * Constructor for the binary dictionary. This is supposed to be called from the 64 * dictionary factory. 65 * All implementations should pass null into flagArray, except for testing purposes. 66 * @param context the context to access the environment from. 67 * @param filename the name of the file to read through native code. 68 * @param offset the offset of the dictionary data within the file. 69 * @param length the length of the binary data. 70 * @param useFullEditDistance whether to use the full edit distance in suggestions 71 * @param dictType the dictionary type, as a human-readable string 72 */ 73 public BinaryDictionary(final Context context, 74 final String filename, final long offset, final long length, 75 final boolean useFullEditDistance, final Locale locale, final String dictType) { 76 super(dictType); 77 mUseFullEditDistance = useFullEditDistance; 78 loadDictionary(filename, offset, length); 79 } 80 81 static { 82 JniUtils.loadNativeLibrary(); 83 } 84 85 private native long openNative(String sourceDir, long dictOffset, long dictSize, 86 int typedLetterMultiplier, int fullWordMultiplier, int maxWordLength, int maxWords); 87 private native void closeNative(long dict); 88 private native int getFrequencyNative(long dict, int[] word, int wordLength); 89 private native boolean isValidBigramNative(long dict, int[] word1, int[] word2); 90 private native int getSuggestionsNative(long dict, long proximityInfo, int[] xCoordinates, 91 int[] yCoordinates, int[] times, int[] pointerIds, int[] inputCodes, int codesSize, 92 int commitPoint, boolean isGesture, 93 int[] prevWordCodePointArray, boolean useFullEditDistance, char[] outputChars, 94 int[] scores, int[] outputIndices); 95 private native int getBigramsNative(long dict, int[] prevWord, int prevWordLength, 96 int[] inputCodes, int inputCodesLength, char[] outputChars, int[] scores, 97 int maxWordLength, int maxBigrams); 98 private static native float calcNormalizedScoreNative( 99 char[] before, int beforeLength, char[] after, int afterLength, int score); 100 private static native int editDistanceNative( 101 char[] before, int beforeLength, char[] after, int afterLength); 102 103 private final void loadDictionary(String path, long startOffset, long length) { 104 mNativeDict = openNative(path, startOffset, length, 105 TYPED_LETTER_MULTIPLIER, FULL_WORD_SCORE_MULTIPLIER, MAX_WORD_LENGTH, MAX_WORDS); 106 } 107 108 @Override 109 public ArrayList<SuggestedWordInfo> getBigrams(final WordComposer codes, 110 final CharSequence previousWord) { 111 if (mNativeDict == 0) return null; 112 113 int[] codePoints = StringUtils.toCodePointArray(previousWord.toString()); 114 Arrays.fill(mOutputChars_bigrams, (char) 0); 115 Arrays.fill(mBigramScores, 0); 116 117 int codesSize = codes.size(); 118 Arrays.fill(mInputCodes, -1); 119 if (codesSize > 0) { 120 mInputCodes[0] = codes.getCodeAt(0); 121 } 122 123 int count = getBigramsNative(mNativeDict, codePoints, codePoints.length, mInputCodes, 124 codesSize, mOutputChars_bigrams, mBigramScores, MAX_WORD_LENGTH, MAX_BIGRAMS); 125 if (count > MAX_BIGRAMS) { 126 count = MAX_BIGRAMS; 127 } 128 129 final ArrayList<SuggestedWordInfo> suggestions = new ArrayList<SuggestedWordInfo>(); 130 for (int j = 0; j < count; ++j) { 131 if (codesSize > 0 && mBigramScores[j] < 1) break; 132 final int start = j * MAX_WORD_LENGTH; 133 int len = 0; 134 while (len < MAX_WORD_LENGTH && mOutputChars_bigrams[start + len] != 0) { 135 ++len; 136 } 137 if (len > 0) { 138 suggestions.add(new SuggestedWordInfo( 139 new String(mOutputChars_bigrams, start, len), 140 mBigramScores[j], SuggestedWordInfo.KIND_CORRECTION, mDictType)); 141 } 142 } 143 return suggestions; 144 } 145 146 // proximityInfo and/or prevWordForBigrams may not be null. 147 @Override 148 public ArrayList<SuggestedWordInfo> getWords(final WordComposer codes, 149 final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo) { 150 final int count = getSuggestions(codes, prevWordForBigrams, proximityInfo, mOutputChars, 151 mScores, mSpaceIndices); 152 153 final ArrayList<SuggestedWordInfo> suggestions = new ArrayList<SuggestedWordInfo>(); 154 for (int j = 0; j < count; ++j) { 155 if (mScores[j] < 1) break; 156 final int start = j * MAX_WORD_LENGTH; 157 int len = 0; 158 while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) { 159 ++len; 160 } 161 if (len > 0) { 162 // TODO: actually get the kind from native code 163 suggestions.add(new SuggestedWordInfo( 164 new String(mOutputChars, start, len), 165 mScores[j], SuggestedWordInfo.KIND_CORRECTION, mDictType)); 166 } 167 } 168 return suggestions; 169 } 170 171 /* package for test */ boolean isValidDictionary() { 172 return mNativeDict != 0; 173 } 174 175 // proximityInfo may not be null. 176 /* package for test */ int getSuggestions(final WordComposer codes, 177 final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo, 178 char[] outputChars, int[] scores, int[] spaceIndices) { 179 if (!isValidDictionary()) return -1; 180 181 final int codesSize = codes.size(); 182 // Won't deal with really long words. 183 if (codesSize > MAX_WORD_LENGTH - 1) return -1; 184 185 Arrays.fill(mInputCodes, WordComposer.NOT_A_CODE); 186 for (int i = 0; i < codesSize; i++) { 187 mInputCodes[i] = codes.getCodeAt(i); 188 } 189 Arrays.fill(outputChars, (char) 0); 190 Arrays.fill(scores, 0); 191 192 // TODO: toLowerCase in the native code 193 final int[] prevWordCodePointArray = (null == prevWordForBigrams) 194 ? null : StringUtils.toCodePointArray(prevWordForBigrams.toString()); 195 196 int[] emptyArray = new int[codesSize]; 197 Arrays.fill(emptyArray, 0); 198 199 //final int commitPoint = codes.getCommitPoint(); 200 //codes.clearCommitPoint(); 201 202 return getSuggestionsNative(mNativeDict, proximityInfo.getNativeProximityInfo(), 203 codes.getXCoordinates(), codes.getYCoordinates(), emptyArray, emptyArray, mInputCodes, 204 codesSize, 0 /* unused */, false, prevWordCodePointArray, mUseFullEditDistance, 205 outputChars, scores, spaceIndices); 206 } 207 208 public static float calcNormalizedScore(String before, String after, int score) { 209 return calcNormalizedScoreNative(before.toCharArray(), before.length(), 210 after.toCharArray(), after.length(), score); 211 } 212 213 public static int editDistance(String before, String after) { 214 return editDistanceNative( 215 before.toCharArray(), before.length(), after.toCharArray(), after.length()); 216 } 217 218 @Override 219 public boolean isValidWord(CharSequence word) { 220 return getFrequency(word) >= 0; 221 } 222 223 @Override 224 public int getFrequency(CharSequence word) { 225 if (word == null) return -1; 226 int[] chars = StringUtils.toCodePointArray(word.toString()); 227 return getFrequencyNative(mNativeDict, chars, chars.length); 228 } 229 230 // TODO: Add a batch process version (isValidBigramMultiple?) to avoid excessive numbers of jni 231 // calls when checking for changes in an entire dictionary. 232 public boolean isValidBigram(CharSequence word1, CharSequence word2) { 233 if (TextUtils.isEmpty(word1) || TextUtils.isEmpty(word2)) return false; 234 int[] chars1 = StringUtils.toCodePointArray(word1.toString()); 235 int[] chars2 = StringUtils.toCodePointArray(word2.toString()); 236 return isValidBigramNative(mNativeDict, chars1, chars2); 237 } 238 239 @Override 240 public synchronized void close() { 241 closeInternal(); 242 } 243 244 private void closeInternal() { 245 if (mNativeDict != 0) { 246 closeNative(mNativeDict); 247 mNativeDict = 0; 248 } 249 } 250 251 @Override 252 protected void finalize() throws Throwable { 253 try { 254 closeInternal(); 255 } finally { 256 super.finalize(); 257 } 258 } 259} 260