/*
* 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.sugree.inputmethod.latin;
import android.content.Context;
import com.android.inputmethod.keyboard.ProximityInfo;
import com.sugree.inputmethod.latin.R;
import java.util.Arrays;
/**
* Implements a static, compacted, binary dictionary of standard words.
*/
public class BinaryDictionary extends Dictionary {
public static final String DICTIONARY_PACK_AUTHORITY =
"com.sugree.inputmethod.latin.dictionarypack";
/**
* There is a 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.
*/
public static final int MAX_WORD_LENGTH = 48;
public static final int MAX_WORDS = 18;
private static final String TAG = "BinaryDictionary";
private static final int MAX_PROXIMITY_CHARS_SIZE = ProximityInfo.MAX_PROXIMITY_CHARS_SIZE;
private static final int MAX_BIGRAMS = 60;
private static final int TYPED_LETTER_MULTIPLIER = 2;
private int mDicTypeId;
private int mNativeDict;
private final int[] mInputCodes = new int[MAX_WORD_LENGTH * MAX_PROXIMITY_CHARS_SIZE];
private final char[] mOutputChars = new char[MAX_WORD_LENGTH * MAX_WORDS];
private final char[] mOutputChars_bigrams = new char[MAX_WORD_LENGTH * MAX_BIGRAMS];
private final int[] mScores = new int[MAX_WORDS];
private final int[] mBigramScores = new int[MAX_BIGRAMS];
public static final Flag FLAG_REQUIRES_GERMAN_UMLAUT_PROCESSING =
new Flag(R.bool.config_require_umlaut_processing, 0x1);
// FULL_EDIT_DISTANCE is a flag that forces the dictionary to use full words
// when computing edit distance, instead of the default behavior of stopping
// the evaluation at the size the user typed.
public static final Flag FLAG_USE_FULL_EDIT_DISTANCE = new Flag(0x2);
// Can create a new flag from extravalue :
// public static final Flag FLAG_MYFLAG =
// new Flag("my_flag", 0x02);
// ALL_CONFIG_FLAGS is a collection of flags that enable reading all flags from configuration.
// This is but a mask - it does not mean the flags will be on, only that the configuration
// will be read for this particular flag.
public static final Flag[] ALL_CONFIG_FLAGS = {
// Here should reside all flags that trigger some special processing
// These *must* match the definition in UnigramDictionary enum in
// unigram_dictionary.h so please update both at the same time.
// Please note that flags created with a resource are of type CONFIG while flags
// created with a string are of type EXTRAVALUE. These behave like masks, and the
// actual value will be read from the configuration/extra value at run time for
// the configuration at dictionary creation time.
FLAG_REQUIRES_GERMAN_UMLAUT_PROCESSING,
};
private int mFlags = 0;
/**
* Constructor for the binary dictionary. This is supposed to be called from the
* dictionary factory.
* All implementations should pass null into flagArray, except for testing purposes.
* @param context the context to access the environment from.
* @param filename the name of the file to read through native code.
* @param offset the offset of the dictionary data within the file.
* @param length the length of the binary data.
* @param flagArray the flags to limit the dictionary to, or null for default.
*/
public BinaryDictionary(final Context context,
final String filename, final long offset, final long length, Flag[] flagArray) {
// Note: at the moment a binary dictionary is always of the "main" type.
// Initializing this here will help transitioning out of the scheme where
// the Suggest class knows everything about every single dictionary.
mDicTypeId = Suggest.DIC_MAIN;
// TODO: Stop relying on the state of SubtypeSwitcher, get it as a parameter
mFlags = Flag.initFlags(null == flagArray ? ALL_CONFIG_FLAGS : flagArray, context,
SubtypeSwitcher.getInstance());
loadDictionary(filename, offset, length);
}
static {
Utils.loadNativeLibrary();
}
private native int openNative(String sourceDir, long dictOffset, long dictSize,
int typedLetterMultiplier, int fullWordMultiplier, int maxWordLength,
int maxWords, int maxAlternatives);
private native void closeNative(int dict);
private native boolean isValidWordNative(int nativeData, char[] word, int wordLength);
private native int getSuggestionsNative(int dict, int proximityInfo, int[] xCoordinates,
int[] yCoordinates, int[] inputCodes, int codesSize, int flags, char[] outputChars,
int[] scores);
private native int getBigramsNative(int dict, char[] prevWord, int prevWordLength,
int[] inputCodes, int inputCodesLength, char[] outputChars, int[] scores,
int maxWordLength, int maxBigrams, int maxAlternatives);
private final void loadDictionary(String path, long startOffset, long length) {
mNativeDict = openNative(path, startOffset, length,
TYPED_LETTER_MULTIPLIER, FULL_WORD_SCORE_MULTIPLIER,
MAX_WORD_LENGTH, MAX_WORDS, MAX_PROXIMITY_CHARS_SIZE);
}
@Override
public void getBigrams(final WordComposer codes, final CharSequence previousWord,
final WordCallback callback) {
if (mNativeDict == 0) return;
char[] chars = previousWord.toString().toCharArray();
Arrays.fill(mOutputChars_bigrams, (char) 0);
Arrays.fill(mBigramScores, 0);
int codesSize = codes.size();
if (codesSize <= 0) {
// Do not return bigrams from BinaryDictionary when nothing was typed.
// Only use user-history bigrams (or whatever other bigram dictionaries decide).
return;
}
Arrays.fill(mInputCodes, -1);
int[] alternatives = codes.getCodesAt(0);
System.arraycopy(alternatives, 0, mInputCodes, 0,
Math.min(alternatives.length, MAX_PROXIMITY_CHARS_SIZE));
int count = getBigramsNative(mNativeDict, chars, chars.length, mInputCodes, codesSize,
mOutputChars_bigrams, mBigramScores, MAX_WORD_LENGTH, MAX_BIGRAMS,
MAX_PROXIMITY_CHARS_SIZE);
for (int j = 0; j < count; ++j) {
if (mBigramScores[j] < 1) break;
final int start = j * MAX_WORD_LENGTH;
int len = 0;
while (len < MAX_WORD_LENGTH && mOutputChars_bigrams[start + len] != 0) {
++len;
}
if (len > 0) {
callback.addWord(mOutputChars_bigrams, start, len, mBigramScores[j],
mDicTypeId, DataType.BIGRAM);
}
}
}
// proximityInfo may not be null.
@Override
public void getWords(final WordComposer codes, final WordCallback callback,
final ProximityInfo proximityInfo) {
final int count = getSuggestions(codes, proximityInfo, mOutputChars, mScores);
for (int j = 0; j < count; ++j) {
if (mScores[j] < 1) break;
final int start = j * MAX_WORD_LENGTH;
int len = 0;
while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) {
++len;
}
if (len > 0) {
callback.addWord(mOutputChars, start, len, mScores[j], mDicTypeId,
DataType.UNIGRAM);
}
}
}
/* package for test */ boolean isValidDictionary() {
return mNativeDict != 0;
}
// proximityInfo may not be null.
/* package for test */ int getSuggestions(final WordComposer codes,
final ProximityInfo proximityInfo, char[] outputChars, int[] scores) {
if (!isValidDictionary()) return -1;
final int codesSize = codes.size();
// Won't deal with really long words.
if (codesSize > MAX_WORD_LENGTH - 1) return -1;
Arrays.fill(mInputCodes, WordComposer.NOT_A_CODE);
for (int i = 0; i < codesSize; i++) {
int[] alternatives = codes.getCodesAt(i);
System.arraycopy(alternatives, 0, mInputCodes, i * MAX_PROXIMITY_CHARS_SIZE,
Math.min(alternatives.length, MAX_PROXIMITY_CHARS_SIZE));
}
Arrays.fill(outputChars, (char) 0);
Arrays.fill(scores, 0);
return getSuggestionsNative(
mNativeDict, proximityInfo.getNativeProximityInfo(),
codes.getXCoordinates(), codes.getYCoordinates(), mInputCodes, codesSize,
mFlags, outputChars, scores);
}
@Override
public boolean isValidWord(CharSequence word) {
if (word == null) return false;
char[] chars = word.toString().toCharArray();
return isValidWordNative(mNativeDict, chars, chars.length);
}
@Override
public synchronized void close() {
closeInternal();
}
private void closeInternal() {
if (mNativeDict != 0) {
closeNative(mNativeDict);
mNativeDict = 0;
}
}
@Override
protected void finalize() throws Throwable {
try {
closeInternal();
} finally {
super.finalize();
}
}
}