/ime/latinime/src/com/googlecode/eyesfree/inputmethod/latin/BinaryDictionary.java
http://eyes-free.googlecode.com/ · Java · 261 lines · 190 code · 29 blank · 42 comment · 38 complexity · 1a010a5a90d730c40dfa44fce0614b6f MD5 · raw file
- /*
- * Copyright (C) 2008 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy of
- * the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations under
- * the License.
- */
- package com.googlecode.eyesfree.inputmethod.latin;
- import android.content.Context;
- import android.util.Log;
- import java.io.IOException;
- import java.io.InputStream;
- import java.nio.ByteBuffer;
- import java.nio.ByteOrder;
- import java.nio.channels.Channels;
- import java.util.Arrays;
- /**
- * Implements a static, compacted, binary dictionary of standard words.
- */
- public class BinaryDictionary extends Dictionary {
- /**
- * There is difference between what java and native code can handle.
- * This value should only be used in BinaryDictionary.java
- * It is necessary to keep it at this value because some languages e.g. German have
- * really long words.
- */
- protected static final int MAX_WORD_LENGTH = 48;
- private static final String TAG = "BinaryDictionary";
- private static final int MAX_ALTERNATIVES = 16;
- private static final int MAX_WORDS = 18;
- private static final int MAX_BIGRAMS = 60;
- private static final int TYPED_LETTER_MULTIPLIER = 2;
- private static final boolean ENABLE_MISSED_CHARACTERS = true;
- private int mDicTypeId;
- private int mNativeDict;
- private int mDictLength;
- private int[] mInputCodes = new int[MAX_WORD_LENGTH * MAX_ALTERNATIVES];
- private char[] mOutputChars = new char[MAX_WORD_LENGTH * MAX_WORDS];
- private char[] mOutputChars_bigrams = new char[MAX_WORD_LENGTH * MAX_BIGRAMS];
- private int[] mFrequencies = new int[MAX_WORDS];
- private int[] mFrequencies_bigrams = new int[MAX_BIGRAMS];
- // Keep a reference to the native dict direct buffer in Java to avoid
- // unexpected deallocation of the direct buffer.
- private ByteBuffer mNativeDictDirectBuffer;
- static {
- try {
- System.loadLibrary("jni_touchlatinime");
- } catch (UnsatisfiedLinkError ule) {
- Log.e("BinaryDictionary", "Could not load native library jni_latinime");
- }
- }
- /**
- * Create a dictionary from a raw resource file
- * @param context application context for reading resources
- * @param resId the resource containing the raw binary dictionary
- */
- public BinaryDictionary(Context context, int[] resId, int dicTypeId) {
- if (resId != null && resId.length > 0 && resId[0] != 0) {
- loadDictionary(context, resId);
- }
- mDicTypeId = dicTypeId;
- }
- /**
- * Create a dictionary from a byte buffer. This is used for testing.
- * @param context application context for reading resources
- * @param byteBuffer a ByteBuffer containing the binary dictionary
- */
- public BinaryDictionary(Context context, ByteBuffer byteBuffer, int dicTypeId) {
- if (byteBuffer != null) {
- if (byteBuffer.isDirect()) {
- mNativeDictDirectBuffer = byteBuffer;
- } else {
- mNativeDictDirectBuffer = ByteBuffer.allocateDirect(byteBuffer.capacity());
- byteBuffer.rewind();
- mNativeDictDirectBuffer.put(byteBuffer);
- }
- mDictLength = byteBuffer.capacity();
- mNativeDict = openNative(mNativeDictDirectBuffer,
- TYPED_LETTER_MULTIPLIER, FULL_WORD_FREQ_MULTIPLIER);
- }
- mDicTypeId = dicTypeId;
- }
- private native int openNative(ByteBuffer bb, int typedLetterMultiplier,
- int fullWordMultiplier);
- private native void closeNative(int dict);
- private native boolean isValidWordNative(int nativeData, char[] word, int wordLength);
- private native int getSuggestionsNative(int dict, int[] inputCodes, int codesSize,
- char[] outputChars, int[] frequencies, int maxWordLength, int maxWords,
- int maxAlternatives, int skipPos, int[] nextLettersFrequencies, int nextLettersSize);
- private native int getBigramsNative(int dict, char[] prevWord, int prevWordLength,
- int[] inputCodes, int inputCodesLength, char[] outputChars, int[] frequencies,
- int maxWordLength, int maxBigrams, int maxAlternatives);
- private final void loadDictionary(Context context, int[] resId) {
- InputStream[] is = null;
- try {
- // merging separated dictionary into one if dictionary is separated
- int total = 0;
- is = new InputStream[resId.length];
- for (int i = 0; i < resId.length; i++) {
- is[i] = context.getResources().openRawResource(resId[i]);
- total += is[i].available();
- }
- mNativeDictDirectBuffer =
- ByteBuffer.allocateDirect(total).order(ByteOrder.nativeOrder());
- int got = 0;
- for (int i = 0; i < resId.length; i++) {
- got += Channels.newChannel(is[i]).read(mNativeDictDirectBuffer);
- }
- if (got != total) {
- Log.e(TAG, "Read " + got + " bytes, expected " + total);
- } else {
- mNativeDict = openNative(mNativeDictDirectBuffer,
- TYPED_LETTER_MULTIPLIER, FULL_WORD_FREQ_MULTIPLIER);
- mDictLength = total;
- }
- } catch (IOException e) {
- Log.w(TAG, "No available memory for binary dictionary");
- } finally {
- try {
- if (is != null) {
- for (int i = 0; i < is.length; i++) {
- is[i].close();
- }
- }
- } catch (IOException e) {
- Log.w(TAG, "Failed to close input stream");
- }
- }
- }
- @Override
- public void getBigrams(final WordComposer codes, final CharSequence previousWord,
- final WordCallback callback, int[] nextLettersFrequencies) {
- char[] chars = previousWord.toString().toCharArray();
- Arrays.fill(mOutputChars_bigrams, (char) 0);
- Arrays.fill(mFrequencies_bigrams, 0);
- int codesSize = codes.size();
- Arrays.fill(mInputCodes, -1);
- int[] alternatives = codes.getCodesAt(0);
- System.arraycopy(alternatives, 0, mInputCodes, 0,
- Math.min(alternatives.length, MAX_ALTERNATIVES));
- int count = getBigramsNative(mNativeDict, chars, chars.length, mInputCodes, codesSize,
- mOutputChars_bigrams, mFrequencies_bigrams, MAX_WORD_LENGTH, MAX_BIGRAMS,
- MAX_ALTERNATIVES);
- for (int j = 0; j < count; j++) {
- if (mFrequencies_bigrams[j] < 1) break;
- int start = j * MAX_WORD_LENGTH;
- int len = 0;
- while (mOutputChars_bigrams[start + len] != 0) {
- len++;
- }
- if (len > 0) {
- callback.addWord(mOutputChars_bigrams, start, len, mFrequencies_bigrams[j],
- mDicTypeId, DataType.BIGRAM);
- }
- }
- }
- @Override
- public void getWords(final WordComposer codes, final WordCallback callback,
- int[] nextLettersFrequencies) {
- final int codesSize = codes.size();
- // Won't deal with really long words.
- if (codesSize > MAX_WORD_LENGTH - 1) return;
-
- Arrays.fill(mInputCodes, -1);
- for (int i = 0; i < codesSize; i++) {
- int[] alternatives = codes.getCodesAt(i);
- System.arraycopy(alternatives, 0, mInputCodes, i * MAX_ALTERNATIVES,
- Math.min(alternatives.length, MAX_ALTERNATIVES));
- }
- Arrays.fill(mOutputChars, (char) 0);
- Arrays.fill(mFrequencies, 0);
- int count = getSuggestionsNative(mNativeDict, mInputCodes, codesSize,
- mOutputChars, mFrequencies,
- MAX_WORD_LENGTH, MAX_WORDS, MAX_ALTERNATIVES, -1,
- nextLettersFrequencies,
- nextLettersFrequencies != null ? nextLettersFrequencies.length : 0);
- // If there aren't sufficient suggestions, search for words by allowing wild cards at
- // the different character positions. This feature is not ready for prime-time as we need
- // to figure out the best ranking for such words compared to proximity corrections and
- // completions.
- if (ENABLE_MISSED_CHARACTERS && count < 5) {
- for (int skip = 0; skip < codesSize; skip++) {
- int tempCount = getSuggestionsNative(mNativeDict, mInputCodes, codesSize,
- mOutputChars, mFrequencies,
- MAX_WORD_LENGTH, MAX_WORDS, MAX_ALTERNATIVES, skip,
- null, 0);
- count = Math.max(count, tempCount);
- if (tempCount > 0) break;
- }
- }
- for (int j = 0; j < count; j++) {
- if (mFrequencies[j] < 1) break;
- int start = j * MAX_WORD_LENGTH;
- int len = 0;
- while (mOutputChars[start + len] != 0) {
- len++;
- }
- if (len > 0) {
- callback.addWord(mOutputChars, start, len, mFrequencies[j], mDicTypeId,
- DataType.UNIGRAM);
- }
- }
- }
- @Override
- public boolean isValidWord(CharSequence word) {
- if (word == null) return false;
- char[] chars = word.toString().toCharArray();
- return isValidWordNative(mNativeDict, chars, chars.length);
- }
- public int getSize() {
- return mDictLength; // This value is initialized on the call to openNative()
- }
- @Override
- public synchronized void close() {
- if (mNativeDict != 0) {
- closeNative(mNativeDict);
- mNativeDict = 0;
- }
- }
- @Override
- protected void finalize() throws Throwable {
- close();
- super.finalize();
- }
- }