/*
* Copyright (C) 2013 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 org.kelar.inputmethod.latin.makedict;
import org.kelar.inputmethod.annotations.UsedForTesting;
import org.kelar.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
import org.kelar.inputmethod.latin.makedict.BinaryDictEncoderUtils.CodePointTable;
import org.kelar.inputmethod.latin.makedict.FormatSpec.FormatOptions;
import org.kelar.inputmethod.latin.makedict.FusionDictionary.PtNode;
import org.kelar.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Objects;
/**
* An implementation of DictEncoder for version 2 binary dictionary.
*/
@UsedForTesting
public class Ver2DictEncoder implements DictEncoder {
private final File mDictFile;
private OutputStream mOutStream;
private byte[] mBuffer;
private int mPosition;
private final int mCodePointTableMode;
public static final int CODE_POINT_TABLE_OFF = 0;
public static final int CODE_POINT_TABLE_ON = 1;
@UsedForTesting
public Ver2DictEncoder(final File dictFile, final int codePointTableMode) {
mDictFile = dictFile;
mOutStream = null;
mBuffer = null;
mCodePointTableMode = codePointTableMode;
}
// This constructor is used only by BinaryDictOffdeviceUtilsTests.
// If you want to use this in the production code, you should consider keeping consistency of
// the interface of Ver3DictDecoder by using factory.
@UsedForTesting
public Ver2DictEncoder(final OutputStream outStream) {
mDictFile = null;
mOutStream = outStream;
mCodePointTableMode = CODE_POINT_TABLE_OFF;
}
private void openStream() throws FileNotFoundException {
mOutStream = new FileOutputStream(mDictFile);
}
private void close() throws IOException {
if (mOutStream != null) {
mOutStream.close();
mOutStream = null;
}
}
// Package for testing
static CodePointTable makeCodePointTable(final FusionDictionary dict) {
final HashMap<Integer, Integer> codePointOccurrenceCounts = new HashMap<>();
for (final WordProperty word : dict) {
// Store per code point occurrence
final String wordString = word.mWord;
for (int i = 0; i < wordString.length(); ++i) {
final int codePoint = Character.codePointAt(wordString, i);
if (codePointOccurrenceCounts.containsKey(codePoint)) {
codePointOccurrenceCounts.put(codePoint,
codePointOccurrenceCounts.get(codePoint) + 1);
} else {
codePointOccurrenceCounts.put(codePoint, 1);
}
}
}
final ArrayList<Entry<Integer, Integer>> codePointOccurrenceArray =
new ArrayList<>(codePointOccurrenceCounts.entrySet());
// Descending order sort by occurrence (value side)
Collections.sort(codePointOccurrenceArray, new Comparator<Entry<Integer, Integer>>() {
@Override
public int compare(final Entry<Integer, Integer> a, final Entry<Integer, Integer> b) {
if (!Objects.equals(a.getValue(), b.getValue())) {
return b.getValue().compareTo(a.getValue());
}
return b.getKey().compareTo(a.getKey());
}
});
int currentCodePointTableIndex = FormatSpec.MINIMAL_ONE_BYTE_CHARACTER_VALUE;
// Temporary map for writing of nodes
final HashMap<Integer, Integer> codePointToOneByteCodeMap = new HashMap<>();
for (final Entry<Integer, Integer> entry : codePointOccurrenceArray) {
// Put a relation from the original code point to the one byte code.
codePointToOneByteCodeMap.put(entry.getKey(), currentCodePointTableIndex);
if (FormatSpec.MAXIMAL_ONE_BYTE_CHARACTER_VALUE < ++currentCodePointTableIndex) {
break;
}
}
// codePointToOneByteCodeMap for writing the trie
// codePointOccurrenceArray for writing the header
return new CodePointTable(codePointToOneByteCodeMap, codePointOccurrenceArray);
}
@Override
public void writeDictionary(final FusionDictionary dict, final FormatOptions formatOptions)
throws IOException, UnsupportedFormatException {
// We no longer support anything but the latest version of v2.
if (formatOptions.mVersion != FormatSpec.VERSION202) {
throw new UnsupportedFormatException(
"The given format options has wrong version number : "
+ formatOptions.mVersion);
}
if (mOutStream == null) {
openStream();
}
// Make code point conversion table ordered by occurrence of code points
// Version 201 or later have codePointTable
final CodePointTable codePointTable;
if (mCodePointTableMode == CODE_POINT_TABLE_OFF || formatOptions.mVersion
< FormatSpec.MINIMUM_SUPPORTED_VERSION_OF_CODE_POINT_TABLE) {
codePointTable = new CodePointTable();
} else {
codePointTable = makeCodePointTable(dict);
}
BinaryDictEncoderUtils.writeDictionaryHeader(mOutStream, dict, formatOptions,
codePointTable.mCodePointOccurrenceArray);
// Addresses are limited to 3 bytes, but since addresses can be relative to each node
// array, the structure itself is not limited to 16MB. However, if it is over 16MB deciding
// the order of the PtNode arrays becomes a quite complicated problem, because though the
// dictionary itself does not have a size limit, each node array must still be within 16MB
// of all its children and parents. As long as this is ensured, the dictionary file may
// grow to any size.
// Leave the choice of the optimal node order to the flattenTree function.
MakedictLog.i("Flattening the tree...");
ArrayList<PtNodeArray> flatNodes = BinaryDictEncoderUtils.flattenTree(dict.mRootNodeArray);
MakedictLog.i("Computing addresses...");
BinaryDictEncoderUtils.computeAddresses(dict, flatNodes,
codePointTable.mCodePointToOneByteCodeMap);
MakedictLog.i("Checking PtNode array...");
if (MakedictLog.DBG) BinaryDictEncoderUtils.checkFlatPtNodeArrayList(flatNodes);
// Create a buffer that matches the final dictionary size.
final PtNodeArray lastNodeArray = flatNodes.get(flatNodes.size() - 1);
final int bufferSize = lastNodeArray.mCachedAddressAfterUpdate + lastNodeArray.mCachedSize;
mBuffer = new byte[bufferSize];
MakedictLog.i("Writing file...");
for (PtNodeArray nodeArray : flatNodes) {
BinaryDictEncoderUtils.writePlacedPtNodeArray(dict, this, nodeArray,
codePointTable.mCodePointToOneByteCodeMap);
}
if (MakedictLog.DBG) BinaryDictEncoderUtils.showStatistics(flatNodes);
mOutStream.write(mBuffer, 0, mPosition);
MakedictLog.i("Done");
close();
}
@Override
public void setPosition(final int position) {
if (mBuffer == null || position < 0 || position >= mBuffer.length) return;
mPosition = position;
}
@Override
public int getPosition() {
return mPosition;
}
@Override
public void writePtNodeCount(final int ptNodeCount) {
final int countSize = BinaryDictIOUtils.getPtNodeCountSize(ptNodeCount);
if (countSize != 1 && countSize != 2) {
throw new RuntimeException("Strange size from getGroupCountSize : " + countSize);
}
final int encodedPtNodeCount = (countSize == 2) ?
(ptNodeCount | FormatSpec.LARGE_PTNODE_ARRAY_SIZE_FIELD_SIZE_FLAG) : ptNodeCount;
mPosition = BinaryDictEncoderUtils.writeUIntToBuffer(mBuffer, mPosition, encodedPtNodeCount,
countSize);
}
private void writePtNodeFlags(final PtNode ptNode,
final HashMap<Integer, Integer> codePointToOneByteCodeMap) {
final int childrenPos = BinaryDictEncoderUtils.getChildrenPosition(ptNode,
codePointToOneByteCodeMap);
mPosition = BinaryDictEncoderUtils.writeUIntToBuffer(mBuffer, mPosition,
BinaryDictEncoderUtils.makePtNodeFlags(ptNode, childrenPos),
FormatSpec.PTNODE_FLAGS_SIZE);
}
private void writeCharacters(final int[] codePoints, final boolean hasSeveralChars,
final HashMap<Integer, Integer> codePointToOneByteCodeMap) {
mPosition = CharEncoding.writeCharArray(codePoints, mBuffer, mPosition,
codePointToOneByteCodeMap);
if (hasSeveralChars) {
mBuffer[mPosition++] = FormatSpec.PTNODE_CHARACTERS_TERMINATOR;
}
}
private void writeFrequency(final int frequency) {
if (frequency >= 0) {
mPosition = BinaryDictEncoderUtils.writeUIntToBuffer(mBuffer, mPosition, frequency,
FormatSpec.PTNODE_FREQUENCY_SIZE);
}
}
private void writeChildrenPosition(final PtNode ptNode,
final HashMap<Integer, Integer> codePointToOneByteCodeMap) {
final int childrenPos = BinaryDictEncoderUtils.getChildrenPosition(ptNode,
codePointToOneByteCodeMap);
mPosition += BinaryDictEncoderUtils.writeChildrenPosition(mBuffer, mPosition,
childrenPos);
}
/**
* Write a bigram attributes list to mBuffer.
*
* @param bigrams the bigram attributes list.
* @param dict the dictionary the node array is a part of (for relative offsets).
*/
private void writeBigrams(final ArrayList<WeightedString> bigrams,
final FusionDictionary dict) {
if (bigrams == null) return;
final Iterator<WeightedString> bigramIterator = bigrams.iterator();
while (bigramIterator.hasNext()) {
final WeightedString bigram = bigramIterator.next();
final PtNode target =
FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord);
final int addressOfBigram = target.mCachedAddressAfterUpdate;
final int unigramFrequencyForThisWord = target.getProbability();
final int offset = addressOfBigram
- (mPosition + FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE);
final int bigramFlags = BinaryDictEncoderUtils.makeBigramFlags(bigramIterator.hasNext(),
offset, bigram.getProbability(), unigramFrequencyForThisWord, bigram.mWord);
mPosition = BinaryDictEncoderUtils.writeUIntToBuffer(mBuffer, mPosition, bigramFlags,
FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE);
mPosition += BinaryDictEncoderUtils.writeChildrenPosition(mBuffer, mPosition,
Math.abs(offset));
}
}
@Override
public void writePtNode(final PtNode ptNode, final FusionDictionary dict,
final HashMap<Integer, Integer> codePointToOneByteCodeMap) {
writePtNodeFlags(ptNode, codePointToOneByteCodeMap);
writeCharacters(ptNode.mChars, ptNode.hasSeveralChars(), codePointToOneByteCodeMap);
writeFrequency(ptNode.getProbability());
writeChildrenPosition(ptNode, codePointToOneByteCodeMap);
writeBigrams(ptNode.mBigrams, dict);
}
}
