BinaryDictionary.java revision 6f233f7ba1ee924844154515dda208bb9b34acb5
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 private static final int MAX_RESULTS = MAX_BIGRAMS > MAX_WORDS ? MAX_BIGRAMS : MAX_WORDS; 50 51 private static final int TYPED_LETTER_MULTIPLIER = 2; 52 53 private long mNativeDict; 54 private final int[] mInputCodes = new int[MAX_WORD_LENGTH]; 55 private final char[] mOutputChars = new char[MAX_WORD_LENGTH * MAX_RESULTS]; 56 private final int[] mSpaceIndices = new int[MAX_SPACES]; 57 private final int[] mOutputScores = new int[MAX_RESULTS]; 58 59 private final boolean mUseFullEditDistance; 60 61 /** 62 * Constructor for the binary dictionary. This is supposed to be called from the 63 * dictionary factory. 64 * All implementations should pass null into flagArray, except for testing purposes. 65 * @param context the context to access the environment from. 66 * @param filename the name of the file to read through native code. 67 * @param offset the offset of the dictionary data within the file. 68 * @param length the length of the binary data. 69 * @param useFullEditDistance whether to use the full edit distance in suggestions 70 * @param dictType the dictionary type, as a human-readable string 71 */ 72 public BinaryDictionary(final Context context, 73 final String filename, final long offset, final long length, 74 final boolean useFullEditDistance, final Locale locale, final String dictType) { 75 super(dictType); 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[] times, int[] pointerIds, int[] inputCodes, int codesSize, 91 int commitPoint, boolean isGesture, 92 int[] prevWordCodePointArray, boolean useFullEditDistance, char[] outputChars, 93 int[] scores, int[] outputIndices); 94 private native int getBigramsNative(long dict, int[] prevWord, int prevWordLength, 95 int[] inputCodes, int inputCodesLength, char[] outputChars, int[] scores, 96 int maxWordLength, int maxBigrams); 97 private static native float calcNormalizedScoreNative( 98 char[] before, int beforeLength, char[] after, int afterLength, int score); 99 private static native int editDistanceNative( 100 char[] before, int beforeLength, char[] after, int afterLength); 101 102 private final void loadDictionary(String path, long startOffset, long length) { 103 mNativeDict = openNative(path, startOffset, length, 104 TYPED_LETTER_MULTIPLIER, FULL_WORD_SCORE_MULTIPLIER, MAX_WORD_LENGTH, MAX_WORDS); 105 } 106 107 @Override 108 public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer, 109 final CharSequence prevWord, final ProximityInfo proximityInfo) { 110 if (composer.size() <= 1) { 111 return TextUtils.isEmpty(prevWord) ? null : getBigramsInternal(composer, prevWord); 112 } else { 113 return getWordsInternal(composer, prevWord, proximityInfo); 114 } 115 } 116 117 // TODO: move to native code 118 private ArrayList<SuggestedWordInfo> getBigramsInternal(final WordComposer codes, 119 final CharSequence previousWord) { 120 if (!isValidDictionary()) return null; 121 122 int[] codePoints = StringUtils.toCodePointArray(previousWord.toString()); 123 Arrays.fill(mOutputChars, (char) 0); 124 Arrays.fill(mOutputScores, 0); 125 126 int codesSize = codes.size(); 127 Arrays.fill(mInputCodes, -1); 128 if (codesSize > 0) { 129 mInputCodes[0] = codes.getCodeAt(0); 130 } 131 132 int count = getBigramsNative(mNativeDict, codePoints, codePoints.length, mInputCodes, 133 codesSize, mOutputChars, mOutputScores, MAX_WORD_LENGTH, MAX_BIGRAMS); 134 if (count > MAX_BIGRAMS) { 135 count = MAX_BIGRAMS; 136 } 137 138 final ArrayList<SuggestedWordInfo> suggestions = new ArrayList<SuggestedWordInfo>(); 139 for (int j = 0; j < count; ++j) { 140 if (codesSize > 0 && mOutputScores[j] < 1) break; 141 final int start = j * MAX_WORD_LENGTH; 142 int len = 0; 143 while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) { 144 ++len; 145 } 146 if (len > 0) { 147 suggestions.add(new SuggestedWordInfo( 148 new String(mOutputChars, start, len), 149 mOutputScores[j], SuggestedWordInfo.KIND_CORRECTION, mDictType)); 150 } 151 } 152 return suggestions; 153 } 154 155 // TODO: move to native code 156 // proximityInfo and/or prevWordForBigrams may not be null. 157 private ArrayList<SuggestedWordInfo> getWordsInternal(final WordComposer codes, 158 final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo) { 159 if (!isValidDictionary()) return null; 160 161 final int count = getSuggestions(codes, prevWordForBigrams, proximityInfo, mOutputChars, 162 mOutputScores, mSpaceIndices); 163 164 final ArrayList<SuggestedWordInfo> suggestions = new ArrayList<SuggestedWordInfo>(); 165 for (int j = 0; j < count; ++j) { 166 if (mOutputScores[j] < 1) break; 167 final int start = j * MAX_WORD_LENGTH; 168 int len = 0; 169 while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) { 170 ++len; 171 } 172 if (len > 0) { 173 // TODO: actually get the kind from native code 174 suggestions.add(new SuggestedWordInfo( 175 new String(mOutputChars, start, len), 176 mOutputScores[j], SuggestedWordInfo.KIND_CORRECTION, mDictType)); 177 } 178 } 179 return suggestions; 180 } 181 182 /* package for test */ boolean isValidDictionary() { 183 return mNativeDict != 0; 184 } 185 186 // proximityInfo may not be null. 187 private int getSuggestions(final WordComposer codes, 188 final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo, 189 char[] outputChars, int[] scores, int[] spaceIndices) { 190 Arrays.fill(mInputCodes, WordComposer.NOT_A_CODE); 191 Arrays.fill(outputChars, (char) 0); 192 Arrays.fill(scores, 0); 193 194 final InputPointers ips = codes.getInputPointers(); 195 final boolean isGesture = codes.isBatchMode(); 196 final int codesSize; 197 if (isGesture) { 198 codesSize = ips.getPointerSize(); 199 } else { 200 codesSize = codes.size(); 201 // Won't deal with really long words. 202 if (codesSize > MAX_WORD_LENGTH - 1) return -1; 203 for (int i = 0; i < codesSize; i++) { 204 mInputCodes[i] = codes.getCodeAt(i); 205 } 206 } 207 208 // TODO: toLowerCase in the native code 209 final int[] prevWordCodePointArray = (null == prevWordForBigrams) 210 ? null : StringUtils.toCodePointArray(prevWordForBigrams.toString()); 211 212 return getSuggestionsNative(mNativeDict, proximityInfo.getNativeProximityInfo(), 213 ips.getXCoordinates(), ips.getYCoordinates(), ips.getTimes(), ips.getPointerIds(), 214 mInputCodes, codesSize, 0 /* unused */, isGesture, prevWordCodePointArray, 215 mUseFullEditDistance, outputChars, scores, spaceIndices); 216 } 217 218 public static float calcNormalizedScore(String before, String after, int score) { 219 return calcNormalizedScoreNative(before.toCharArray(), before.length(), 220 after.toCharArray(), after.length(), score); 221 } 222 223 public static int editDistance(String before, String after) { 224 return editDistanceNative( 225 before.toCharArray(), before.length(), after.toCharArray(), after.length()); 226 } 227 228 @Override 229 public boolean isValidWord(CharSequence word) { 230 return getFrequency(word) >= 0; 231 } 232 233 @Override 234 public int getFrequency(CharSequence word) { 235 if (word == null) return -1; 236 int[] chars = StringUtils.toCodePointArray(word.toString()); 237 return getFrequencyNative(mNativeDict, chars, chars.length); 238 } 239 240 // TODO: Add a batch process version (isValidBigramMultiple?) to avoid excessive numbers of jni 241 // calls when checking for changes in an entire dictionary. 242 public boolean isValidBigram(CharSequence word1, CharSequence word2) { 243 if (TextUtils.isEmpty(word1) || TextUtils.isEmpty(word2)) return false; 244 int[] chars1 = StringUtils.toCodePointArray(word1.toString()); 245 int[] chars2 = StringUtils.toCodePointArray(word2.toString()); 246 return isValidBigramNative(mNativeDict, chars1, chars2); 247 } 248 249 @Override 250 public synchronized void close() { 251 closeInternal(); 252 } 253 254 private void closeInternal() { 255 if (mNativeDict != 0) { 256 closeNative(mNativeDict); 257 mNativeDict = 0; 258 } 259 } 260 261 @Override 262 protected void finalize() throws Throwable { 263 try { 264 closeInternal(); 265 } finally { 266 super.finalize(); 267 } 268 } 269} 270