623 lines
26 KiB
Java
623 lines
26 KiB
Java
/*
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* Copyright (C) 2013 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.android.inputmethod.latin.makedict;
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import com.android.inputmethod.annotations.UsedForTesting;
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import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
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import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
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import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
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import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
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import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
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import java.io.File;
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import java.io.FileInputStream;
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import java.io.FileNotFoundException;
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import java.io.IOException;
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import java.io.OutputStream;
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import java.nio.ByteBuffer;
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import java.nio.channels.FileChannel;
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import java.util.ArrayList;
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import java.util.Map;
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import java.util.TreeMap;
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/**
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* Decodes binary files for a FusionDictionary.
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*
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* All the methods in this class are static.
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*
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* TODO: Remove calls from classes except Ver3DictDecoder
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* TODO: Move this file to makedict/internal.
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* TODO: Rename this class to DictDecoderUtils.
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*/
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public final class BinaryDictDecoderUtils {
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private static final boolean DBG = MakedictLog.DBG;
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private BinaryDictDecoderUtils() {
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// This utility class is not publicly instantiable.
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}
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private static final int MAX_JUMPS = 12;
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@UsedForTesting
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public interface DictBuffer {
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public int readUnsignedByte();
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public int readUnsignedShort();
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public int readUnsignedInt24();
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public int readInt();
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public int position();
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public void position(int newPosition);
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public void put(final byte b);
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public int limit();
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@UsedForTesting
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public int capacity();
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}
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public static final class ByteBufferDictBuffer implements DictBuffer {
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private ByteBuffer mBuffer;
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public ByteBufferDictBuffer(final ByteBuffer buffer) {
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mBuffer = buffer;
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}
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@Override
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public int readUnsignedByte() {
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return mBuffer.get() & 0xFF;
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}
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@Override
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public int readUnsignedShort() {
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return mBuffer.getShort() & 0xFFFF;
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}
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@Override
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public int readUnsignedInt24() {
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final int retval = readUnsignedByte();
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return (retval << 16) + readUnsignedShort();
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}
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@Override
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public int readInt() {
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return mBuffer.getInt();
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}
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@Override
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public int position() {
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return mBuffer.position();
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}
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@Override
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public void position(int newPos) {
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mBuffer.position(newPos);
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}
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@Override
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public void put(final byte b) {
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mBuffer.put(b);
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}
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@Override
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public int limit() {
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return mBuffer.limit();
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}
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@Override
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public int capacity() {
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return mBuffer.capacity();
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}
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}
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/**
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* A class grouping utility function for our specific character encoding.
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*/
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static final class CharEncoding {
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private static final int MINIMAL_ONE_BYTE_CHARACTER_VALUE = 0x20;
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private static final int MAXIMAL_ONE_BYTE_CHARACTER_VALUE = 0xFF;
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/**
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* Helper method to find out whether this code fits on one byte
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*/
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private static boolean fitsOnOneByte(final int character) {
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return character >= MINIMAL_ONE_BYTE_CHARACTER_VALUE
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&& character <= MAXIMAL_ONE_BYTE_CHARACTER_VALUE;
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}
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/**
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* Compute the size of a character given its character code.
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*
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* Char format is:
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* 1 byte = bbbbbbbb match
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* case 000xxxxx: xxxxx << 16 + next byte << 8 + next byte
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* else: if 00011111 (= 0x1F) : this is the terminator. This is a relevant choice because
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* unicode code points range from 0 to 0x10FFFF, so any 3-byte value starting with
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* 00011111 would be outside unicode.
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* else: iso-latin-1 code
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* This allows for the whole unicode range to be encoded, including chars outside of
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* the BMP. Also everything in the iso-latin-1 charset is only 1 byte, except control
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* characters which should never happen anyway (and still work, but take 3 bytes).
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*
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* @param character the character code.
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* @return the size in binary encoded-form, either 1 or 3 bytes.
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*/
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static int getCharSize(final int character) {
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// See char encoding in FusionDictionary.java
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if (fitsOnOneByte(character)) return 1;
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if (FormatSpec.INVALID_CHARACTER == character) return 1;
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return 3;
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}
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/**
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* Compute the byte size of a character array.
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*/
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static int getCharArraySize(final int[] chars) {
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int size = 0;
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for (int character : chars) size += getCharSize(character);
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return size;
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}
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/**
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* Writes a char array to a byte buffer.
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*
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* @param codePoints the code point array to write.
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* @param buffer the byte buffer to write to.
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* @param index the index in buffer to write the character array to.
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* @return the index after the last character.
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*/
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static int writeCharArray(final int[] codePoints, final byte[] buffer, int index) {
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for (int codePoint : codePoints) {
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if (1 == getCharSize(codePoint)) {
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buffer[index++] = (byte)codePoint;
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} else {
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buffer[index++] = (byte)(0xFF & (codePoint >> 16));
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buffer[index++] = (byte)(0xFF & (codePoint >> 8));
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buffer[index++] = (byte)(0xFF & codePoint);
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}
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}
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return index;
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}
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/**
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* Writes a string with our character format to a byte buffer.
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*
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* This will also write the terminator byte.
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*
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* @param buffer the byte buffer to write to.
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* @param origin the offset to write from.
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* @param word the string to write.
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* @return the size written, in bytes.
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*/
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static int writeString(final byte[] buffer, final int origin,
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final String word) {
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final int length = word.length();
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int index = origin;
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for (int i = 0; i < length; i = word.offsetByCodePoints(i, 1)) {
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final int codePoint = word.codePointAt(i);
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if (1 == getCharSize(codePoint)) {
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buffer[index++] = (byte)codePoint;
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} else {
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buffer[index++] = (byte)(0xFF & (codePoint >> 16));
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buffer[index++] = (byte)(0xFF & (codePoint >> 8));
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buffer[index++] = (byte)(0xFF & codePoint);
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}
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}
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buffer[index++] = FormatSpec.PTNODE_CHARACTERS_TERMINATOR;
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return index - origin;
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}
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/**
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* Writes a string with our character format to an OutputStream.
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*
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* This will also write the terminator byte.
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*
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* @param buffer the OutputStream to write to.
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* @param word the string to write.
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*/
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static void writeString(final OutputStream buffer, final String word) throws IOException {
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final int length = word.length();
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for (int i = 0; i < length; i = word.offsetByCodePoints(i, 1)) {
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final int codePoint = word.codePointAt(i);
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if (1 == getCharSize(codePoint)) {
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buffer.write((byte) codePoint);
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} else {
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buffer.write((byte) (0xFF & (codePoint >> 16)));
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buffer.write((byte) (0xFF & (codePoint >> 8)));
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buffer.write((byte) (0xFF & codePoint));
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}
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}
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buffer.write(FormatSpec.PTNODE_CHARACTERS_TERMINATOR);
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}
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/**
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* Reads a string from a DictBuffer. This is the converse of the above method.
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*/
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static String readString(final DictBuffer dictBuffer) {
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final StringBuilder s = new StringBuilder();
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int character = readChar(dictBuffer);
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while (character != FormatSpec.INVALID_CHARACTER) {
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s.appendCodePoint(character);
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character = readChar(dictBuffer);
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}
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return s.toString();
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}
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/**
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* Reads a character from the buffer.
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*
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* This follows the character format documented earlier in this source file.
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*
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* @param dictBuffer the buffer, positioned over an encoded character.
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* @return the character code.
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*/
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static int readChar(final DictBuffer dictBuffer) {
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int character = dictBuffer.readUnsignedByte();
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if (!fitsOnOneByte(character)) {
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if (FormatSpec.PTNODE_CHARACTERS_TERMINATOR == character) {
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return FormatSpec.INVALID_CHARACTER;
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}
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character <<= 16;
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character += dictBuffer.readUnsignedShort();
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}
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return character;
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}
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}
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// Input methods: Read a binary dictionary to memory.
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// readDictionaryBinary is the public entry point for them.
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static int readSInt24(final DictBuffer dictBuffer) {
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final int retval = dictBuffer.readUnsignedInt24();
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final int sign = ((retval & FormatSpec.MSB24) != 0) ? -1 : 1;
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return sign * (retval & FormatSpec.SINT24_MAX);
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}
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static int readChildrenAddress(final DictBuffer dictBuffer,
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final int optionFlags, final FormatOptions options) {
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if (options.mSupportsDynamicUpdate) {
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final int address = dictBuffer.readUnsignedInt24();
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if (address == 0) return FormatSpec.NO_CHILDREN_ADDRESS;
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if ((address & FormatSpec.MSB24) != 0) {
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return -(address & FormatSpec.SINT24_MAX);
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} else {
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return address;
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}
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}
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switch (optionFlags & FormatSpec.MASK_CHILDREN_ADDRESS_TYPE) {
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case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE:
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return dictBuffer.readUnsignedByte();
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case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES:
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return dictBuffer.readUnsignedShort();
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case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES:
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return dictBuffer.readUnsignedInt24();
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case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS:
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default:
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return FormatSpec.NO_CHILDREN_ADDRESS;
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}
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}
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static int readParentAddress(final DictBuffer dictBuffer,
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final FormatOptions formatOptions) {
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if (BinaryDictIOUtils.supportsDynamicUpdate(formatOptions)) {
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final int parentAddress = dictBuffer.readUnsignedInt24();
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final int sign = ((parentAddress & FormatSpec.MSB24) != 0) ? -1 : 1;
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return sign * (parentAddress & FormatSpec.SINT24_MAX);
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} else {
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return FormatSpec.NO_PARENT_ADDRESS;
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}
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}
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/**
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* Reads and returns the PtNode count out of a buffer and forwards the pointer.
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*/
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/* package */ static int readPtNodeCount(final DictBuffer dictBuffer) {
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final int msb = dictBuffer.readUnsignedByte();
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if (FormatSpec.MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT >= msb) {
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return msb;
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} else {
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return ((FormatSpec.MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT & msb) << 8)
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+ dictBuffer.readUnsignedByte();
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}
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}
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/**
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* Finds, as a string, the word at the position passed as an argument.
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*
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* @param dictDecoder the dict decoder.
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* @param headerSize the size of the header.
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* @param pos the position to seek.
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* @param formatOptions file format options.
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* @return the word with its frequency, as a weighted string.
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*/
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/* package for tests */ static WeightedString getWordAtPosition(final DictDecoder dictDecoder,
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final int headerSize, final int pos, final FormatOptions formatOptions) {
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final WeightedString result;
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final int originalPos = dictDecoder.getPosition();
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dictDecoder.setPosition(pos);
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if (BinaryDictIOUtils.supportsDynamicUpdate(formatOptions)) {
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result = getWordAtPositionWithParentAddress(dictDecoder, pos, formatOptions);
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} else {
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result = getWordAtPositionWithoutParentAddress(dictDecoder, headerSize, pos,
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formatOptions);
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}
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dictDecoder.setPosition(originalPos);
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return result;
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}
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@SuppressWarnings("unused")
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private static WeightedString getWordAtPositionWithParentAddress(final DictDecoder dictDecoder,
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final int pos, final FormatOptions options) {
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int currentPos = pos;
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int frequency = Integer.MIN_VALUE;
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final StringBuilder builder = new StringBuilder();
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// the length of the path from the root to the leaf is limited by MAX_WORD_LENGTH
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for (int count = 0; count < FormatSpec.MAX_WORD_LENGTH; ++count) {
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PtNodeInfo currentInfo;
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int loopCounter = 0;
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do {
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dictDecoder.setPosition(currentPos);
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currentInfo = dictDecoder.readPtNode(currentPos, options);
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if (BinaryDictIOUtils.isMovedPtNode(currentInfo.mFlags, options)) {
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currentPos = currentInfo.mParentAddress + currentInfo.mOriginalAddress;
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}
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if (DBG && loopCounter++ > MAX_JUMPS) {
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MakedictLog.d("Too many jumps - probably a bug");
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}
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} while (BinaryDictIOUtils.isMovedPtNode(currentInfo.mFlags, options));
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if (Integer.MIN_VALUE == frequency) frequency = currentInfo.mFrequency;
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builder.insert(0,
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new String(currentInfo.mCharacters, 0, currentInfo.mCharacters.length));
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if (currentInfo.mParentAddress == FormatSpec.NO_PARENT_ADDRESS) break;
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currentPos = currentInfo.mParentAddress + currentInfo.mOriginalAddress;
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}
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return new WeightedString(builder.toString(), frequency);
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}
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private static WeightedString getWordAtPositionWithoutParentAddress(
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final DictDecoder dictDecoder, final int headerSize, final int pos,
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final FormatOptions options) {
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dictDecoder.setPosition(headerSize);
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final int count = dictDecoder.readPtNodeCount();
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int groupPos = headerSize + BinaryDictIOUtils.getPtNodeCountSize(count);
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final StringBuilder builder = new StringBuilder();
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WeightedString result = null;
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PtNodeInfo last = null;
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for (int i = count - 1; i >= 0; --i) {
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PtNodeInfo info = dictDecoder.readPtNode(groupPos, options);
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groupPos = info.mEndAddress;
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if (info.mOriginalAddress == pos) {
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builder.append(new String(info.mCharacters, 0, info.mCharacters.length));
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result = new WeightedString(builder.toString(), info.mFrequency);
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break; // and return
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}
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if (BinaryDictIOUtils.hasChildrenAddress(info.mChildrenAddress)) {
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if (info.mChildrenAddress > pos) {
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if (null == last) continue;
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builder.append(new String(last.mCharacters, 0, last.mCharacters.length));
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dictDecoder.setPosition(last.mChildrenAddress);
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i = dictDecoder.readPtNodeCount();
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groupPos = last.mChildrenAddress + BinaryDictIOUtils.getPtNodeCountSize(i);
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last = null;
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continue;
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}
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last = info;
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}
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if (0 == i && BinaryDictIOUtils.hasChildrenAddress(last.mChildrenAddress)) {
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builder.append(new String(last.mCharacters, 0, last.mCharacters.length));
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dictDecoder.setPosition(last.mChildrenAddress);
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i = dictDecoder.readPtNodeCount();
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groupPos = last.mChildrenAddress + BinaryDictIOUtils.getPtNodeCountSize(i);
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last = null;
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continue;
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}
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}
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return result;
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}
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/**
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* Reads a single node array from a buffer.
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*
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* This methods reads the file at the current position. A node array is fully expected to start
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* at the current position.
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* This will recursively read other node arrays into the structure, populating the reverse
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* maps on the fly and using them to keep track of already read nodes.
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*
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* @param dictDecoder the dict decoder, correctly positioned at the start of a node array.
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* @param headerSize the size, in bytes, of the file header.
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* @param reverseNodeArrayMap a mapping from addresses to already read node arrays.
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* @param reversePtNodeMap a mapping from addresses to already read PtNodes.
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* @param options file format options.
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* @return the read node array with all his children already read.
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*/
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private static PtNodeArray readNodeArray(final DictDecoder dictDecoder,
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final int headerSize, final Map<Integer, PtNodeArray> reverseNodeArrayMap,
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final Map<Integer, PtNode> reversePtNodeMap, final FormatOptions options)
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throws IOException {
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final ArrayList<PtNode> nodeArrayContents = new ArrayList<PtNode>();
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final int nodeArrayOriginPos = dictDecoder.getPosition();
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do { // Scan the linked-list node.
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final int nodeArrayHeadPos = dictDecoder.getPosition();
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final int count = dictDecoder.readPtNodeCount();
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int groupOffsetPos = nodeArrayHeadPos + BinaryDictIOUtils.getPtNodeCountSize(count);
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for (int i = count; i > 0; --i) { // Scan the array of PtNode.
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PtNodeInfo info = dictDecoder.readPtNode(groupOffsetPos, options);
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if (BinaryDictIOUtils.isMovedPtNode(info.mFlags, options)) continue;
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ArrayList<WeightedString> shortcutTargets = info.mShortcutTargets;
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ArrayList<WeightedString> bigrams = null;
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if (null != info.mBigrams) {
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bigrams = new ArrayList<WeightedString>();
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for (PendingAttribute bigram : info.mBigrams) {
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final WeightedString word = getWordAtPosition(dictDecoder, headerSize,
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bigram.mAddress, options);
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final int reconstructedFrequency =
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BinaryDictIOUtils.reconstructBigramFrequency(word.mFrequency,
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bigram.mFrequency);
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bigrams.add(new WeightedString(word.mWord, reconstructedFrequency));
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}
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}
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if (BinaryDictIOUtils.hasChildrenAddress(info.mChildrenAddress)) {
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PtNodeArray children = reverseNodeArrayMap.get(info.mChildrenAddress);
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if (null == children) {
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final int currentPosition = dictDecoder.getPosition();
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dictDecoder.setPosition(info.mChildrenAddress);
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children = readNodeArray(dictDecoder, headerSize, reverseNodeArrayMap,
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reversePtNodeMap, options);
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dictDecoder.setPosition(currentPosition);
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}
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nodeArrayContents.add(
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new PtNode(info.mCharacters, shortcutTargets, bigrams,
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info.mFrequency,
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0 != (info.mFlags & FormatSpec.FLAG_IS_NOT_A_WORD),
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0 != (info.mFlags & FormatSpec.FLAG_IS_BLACKLISTED), children));
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} else {
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nodeArrayContents.add(
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new PtNode(info.mCharacters, shortcutTargets, bigrams,
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info.mFrequency,
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0 != (info.mFlags & FormatSpec.FLAG_IS_NOT_A_WORD),
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0 != (info.mFlags & FormatSpec.FLAG_IS_BLACKLISTED)));
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}
|
|
groupOffsetPos = info.mEndAddress;
|
|
}
|
|
|
|
// reach the end of the array.
|
|
if (options.mSupportsDynamicUpdate) {
|
|
final boolean hasValidForwardLink = dictDecoder.readAndFollowForwardLink();
|
|
if (!hasValidForwardLink) break;
|
|
}
|
|
} while (options.mSupportsDynamicUpdate && dictDecoder.hasNextPtNodeArray());
|
|
|
|
final PtNodeArray nodeArray = new PtNodeArray(nodeArrayContents);
|
|
nodeArray.mCachedAddressBeforeUpdate = nodeArrayOriginPos;
|
|
nodeArray.mCachedAddressAfterUpdate = nodeArrayOriginPos;
|
|
reverseNodeArrayMap.put(nodeArray.mCachedAddressAfterUpdate, nodeArray);
|
|
return nodeArray;
|
|
}
|
|
|
|
/**
|
|
* Helper function to get the binary format version from the header.
|
|
* @throws IOException
|
|
*/
|
|
private static int getFormatVersion(final DictBuffer dictBuffer)
|
|
throws IOException {
|
|
final int magic = dictBuffer.readInt();
|
|
if (FormatSpec.MAGIC_NUMBER == magic) return dictBuffer.readUnsignedShort();
|
|
return FormatSpec.NOT_A_VERSION_NUMBER;
|
|
}
|
|
|
|
/**
|
|
* Helper function to get and validate the binary format version.
|
|
* @throws UnsupportedFormatException
|
|
* @throws IOException
|
|
*/
|
|
static int checkFormatVersion(final DictBuffer dictBuffer)
|
|
throws IOException, UnsupportedFormatException {
|
|
final int version = getFormatVersion(dictBuffer);
|
|
if (version < FormatSpec.MINIMUM_SUPPORTED_VERSION
|
|
|| version > FormatSpec.MAXIMUM_SUPPORTED_VERSION) {
|
|
throw new UnsupportedFormatException("This file has version " + version
|
|
+ ", but this implementation does not support versions above "
|
|
+ FormatSpec.MAXIMUM_SUPPORTED_VERSION);
|
|
}
|
|
return version;
|
|
}
|
|
|
|
/**
|
|
* Reads a buffer and returns the memory representation of the dictionary.
|
|
*
|
|
* This high-level method takes a buffer and reads its contents, populating a
|
|
* FusionDictionary structure. The optional dict argument is an existing dictionary to
|
|
* which words from the buffer should be added. If it is null, a new dictionary is created.
|
|
*
|
|
* @param dictDecoder the dict decoder.
|
|
* @param dict an optional dictionary to add words to, or null.
|
|
* @return the created (or merged) dictionary.
|
|
*/
|
|
@UsedForTesting
|
|
/* package */ static FusionDictionary readDictionaryBinary(final DictDecoder dictDecoder,
|
|
final FusionDictionary dict) throws IOException, UnsupportedFormatException {
|
|
// Read header
|
|
final FileHeader fileHeader = dictDecoder.readHeader();
|
|
|
|
Map<Integer, PtNodeArray> reverseNodeArrayMapping = new TreeMap<Integer, PtNodeArray>();
|
|
Map<Integer, PtNode> reversePtNodeMapping = new TreeMap<Integer, PtNode>();
|
|
final PtNodeArray root = readNodeArray(dictDecoder, fileHeader.mHeaderSize,
|
|
reverseNodeArrayMapping, reversePtNodeMapping, fileHeader.mFormatOptions);
|
|
|
|
FusionDictionary newDict = new FusionDictionary(root, fileHeader.mDictionaryOptions);
|
|
if (null != dict) {
|
|
for (final Word w : dict) {
|
|
if (w.mIsBlacklistEntry) {
|
|
newDict.addBlacklistEntry(w.mWord, w.mShortcutTargets, w.mIsNotAWord);
|
|
} else {
|
|
newDict.add(w.mWord, w.mFrequency, w.mShortcutTargets, w.mIsNotAWord);
|
|
}
|
|
}
|
|
for (final Word w : dict) {
|
|
// By construction a binary dictionary may not have bigrams pointing to
|
|
// words that are not also registered as unigrams so we don't have to avoid
|
|
// them explicitly here.
|
|
for (final WeightedString bigram : w.mBigrams) {
|
|
newDict.setBigram(w.mWord, bigram.mWord, bigram.mFrequency);
|
|
}
|
|
}
|
|
}
|
|
|
|
return newDict;
|
|
}
|
|
|
|
/**
|
|
* Helper method to pass a file name instead of a File object to isBinaryDictionary.
|
|
*/
|
|
public static boolean isBinaryDictionary(final String filename) {
|
|
final File file = new File(filename);
|
|
return isBinaryDictionary(file);
|
|
}
|
|
|
|
/**
|
|
* Basic test to find out whether the file is a binary dictionary or not.
|
|
*
|
|
* Concretely this only tests the magic number.
|
|
*
|
|
* @param file The file to test.
|
|
* @return true if it's a binary dictionary, false otherwise
|
|
*/
|
|
public static boolean isBinaryDictionary(final File file) {
|
|
FileInputStream inStream = null;
|
|
try {
|
|
inStream = new FileInputStream(file);
|
|
final ByteBuffer buffer = inStream.getChannel().map(
|
|
FileChannel.MapMode.READ_ONLY, 0, file.length());
|
|
final int version = getFormatVersion(new ByteBufferDictBuffer(buffer));
|
|
return (version >= FormatSpec.MINIMUM_SUPPORTED_VERSION
|
|
&& version <= FormatSpec.MAXIMUM_SUPPORTED_VERSION);
|
|
} catch (FileNotFoundException e) {
|
|
return false;
|
|
} catch (IOException e) {
|
|
return false;
|
|
} finally {
|
|
if (inStream != null) {
|
|
try {
|
|
inStream.close();
|
|
} catch (IOException e) {
|
|
// do nothing
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|