BinaryDictionary.java revision 5bb420627520412a621121f5c21da123f6a4cb1c
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_PREDICTIONS = 60; 49 private static final int MAX_RESULTS = Math.max(MAX_PREDICTIONS, 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 private final int[] mOutputTypes = new int[MAX_RESULTS]; 59 60 private final boolean mUseFullEditDistance; 61 private final DicTraverseSession mDicTraverseSession; 62 63 /** 64 * Constructor for the binary dictionary. This is supposed to be called from the 65 * dictionary factory. 66 * All implementations should pass null into flagArray, except for testing purposes. 67 * @param context the context to access the environment from. 68 * @param filename the name of the file to read through native code. 69 * @param offset the offset of the dictionary data within the file. 70 * @param length the length of the binary data. 71 * @param useFullEditDistance whether to use the full edit distance in suggestions 72 * @param dictType the dictionary type, as a human-readable string 73 */ 74 public BinaryDictionary(final Context context, 75 final String filename, final long offset, final long length, 76 final boolean useFullEditDistance, final Locale locale, final String dictType) { 77 super(dictType); 78 mUseFullEditDistance = useFullEditDistance; 79 loadDictionary(filename, offset, length); 80 mDicTraverseSession = new DicTraverseSession(locale); 81 } 82 83 static { 84 JniUtils.loadNativeLibrary(); 85 } 86 87 private native long openNative(String sourceDir, long dictOffset, long dictSize, 88 int typedLetterMultiplier, int fullWordMultiplier, int maxWordLength, int maxWords, 89 int maxPredictions); 90 private native void closeNative(long dict); 91 private native int getFrequencyNative(long dict, int[] word); 92 private native boolean isValidBigramNative(long dict, int[] word1, int[] word2); 93 private native int getSuggestionsNative(long dict, long proximityInfo, long traverseSession, 94 int[] xCoordinates, int[] yCoordinates, int[] times, int[] pointerIds, 95 int[] inputCodes, int codesSize, int commitPoint, boolean isGesture, 96 int[] prevWordCodePointArray, boolean useFullEditDistance, char[] outputChars, 97 int[] outputScores, int[] outputIndices, int[] outputTypes); 98 private static native float calcNormalizedScoreNative(char[] before, char[] after, int score); 99 private static native int editDistanceNative(char[] before, char[] after); 100 101 private final void loadDictionary(String path, long startOffset, long length) { 102 mNativeDict = openNative(path, startOffset, length, TYPED_LETTER_MULTIPLIER, 103 FULL_WORD_SCORE_MULTIPLIER, MAX_WORD_LENGTH, MAX_WORDS, MAX_PREDICTIONS); 104 } 105 106 @Override 107 public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer, 108 final CharSequence prevWord, final ProximityInfo proximityInfo) { 109 if (!isValidDictionary()) return null; 110 Arrays.fill(mInputCodes, WordComposer.NOT_A_CODE); 111 Arrays.fill(mOutputChars, (char) 0); 112 Arrays.fill(mOutputScores, 0); 113 // TODO: toLowerCase in the native code 114 final int[] prevWordCodePointArray = (null == prevWord) 115 ? null : StringUtils.toCodePointArray(prevWord.toString()); 116 final int composerSize = composer.size(); 117 118 final boolean isGesture = composer.isBatchMode(); 119 if (composerSize <= 1 || !isGesture) { 120 if (composerSize > MAX_WORD_LENGTH - 1) return null; 121 for (int i = 0; i < composerSize; i++) { 122 mInputCodes[i] = composer.getCodeAt(i); 123 } 124 } 125 126 final InputPointers ips = composer.getInputPointers(); 127 final int codesSize = isGesture ? ips.getPointerSize() : composerSize; 128 // proximityInfo and/or prevWordForBigrams may not be null. 129 final int tmpCount = getSuggestionsNative(mNativeDict, 130 proximityInfo.getNativeProximityInfo(), 131 mDicTraverseSession.getSession(), ips.getXCoordinates(), 132 ips.getYCoordinates(), ips.getTimes(), ips.getPointerIds(), 133 mInputCodes, codesSize, 0 /* commitPoint */, isGesture, prevWordCodePointArray, 134 mUseFullEditDistance, mOutputChars, mOutputScores, mSpaceIndices, mOutputTypes); 135 final int count = Math.min(tmpCount, MAX_PREDICTIONS); 136 137 final ArrayList<SuggestedWordInfo> suggestions = new ArrayList<SuggestedWordInfo>(); 138 for (int j = 0; j < count; ++j) { 139 if (composerSize > 0 && mOutputScores[j] < 1) break; 140 final int start = j * MAX_WORD_LENGTH; 141 int len = 0; 142 while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) { 143 ++len; 144 } 145 if (len > 0) { 146 suggestions.add(new SuggestedWordInfo( 147 new String(mOutputChars, start, len), 148 mOutputScores[j], SuggestedWordInfo.KIND_CORRECTION, mDictType)); 149 } 150 } 151 return suggestions; 152 } 153 154 /* package for test */ boolean isValidDictionary() { 155 return mNativeDict != 0; 156 } 157 158 public static float calcNormalizedScore(String before, String after, int score) { 159 return calcNormalizedScoreNative(before.toCharArray(), after.toCharArray(), score); 160 } 161 162 public static int editDistance(String before, String after) { 163 return editDistanceNative(before.toCharArray(), after.toCharArray()); 164 } 165 166 @Override 167 public boolean isValidWord(CharSequence word) { 168 return getFrequency(word) >= 0; 169 } 170 171 @Override 172 public int getFrequency(CharSequence word) { 173 if (word == null) return -1; 174 int[] codePoints = StringUtils.toCodePointArray(word.toString()); 175 return getFrequencyNative(mNativeDict, codePoints); 176 } 177 178 // TODO: Add a batch process version (isValidBigramMultiple?) to avoid excessive numbers of jni 179 // calls when checking for changes in an entire dictionary. 180 public boolean isValidBigram(CharSequence word1, CharSequence word2) { 181 if (TextUtils.isEmpty(word1) || TextUtils.isEmpty(word2)) return false; 182 int[] chars1 = StringUtils.toCodePointArray(word1.toString()); 183 int[] chars2 = StringUtils.toCodePointArray(word2.toString()); 184 return isValidBigramNative(mNativeDict, chars1, chars2); 185 } 186 187 @Override 188 public synchronized void close() { 189 mDicTraverseSession.close(); 190 closeInternal(); 191 } 192 193 private void closeInternal() { 194 if (mNativeDict != 0) { 195 closeNative(mNativeDict); 196 mNativeDict = 0; 197 } 198 } 199 200 @Override 201 protected void finalize() throws Throwable { 202 try { 203 closeInternal(); 204 } finally { 205 super.finalize(); 206 } 207 } 208} 209