1025 lines
43 KiB
Java
1025 lines
43 KiB
Java
/*
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* Copyright (C) 2011 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not
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* use this file except in compliance with the License. You may obtain a copy of
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* 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, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations under
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* the License.
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*/
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package com.android.inputmethod.latin;
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import com.android.inputmethod.latin.FusionDictionary.CharGroup;
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import com.android.inputmethod.latin.FusionDictionary.Node;
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import com.android.inputmethod.latin.FusionDictionary.WeightedString;
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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.io.RandomAccessFile;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Map;
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import java.util.TreeMap;
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/**
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* Reads and writes XML 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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public class BinaryDictInputOutput {
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/* Node layout is as follows:
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* | addressType xx : mask with MASK_GROUP_ADDRESS_TYPE
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* 2 bits, 00 = no children : FLAG_GROUP_ADDRESS_TYPE_NOADDRESS
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* f | 01 = 1 byte : FLAG_GROUP_ADDRESS_TYPE_ONEBYTE
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* l | 10 = 2 bytes : FLAG_GROUP_ADDRESS_TYPE_TWOBYTES
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* a | 11 = 3 bytes : FLAG_GROUP_ADDRESS_TYPE_THREEBYTES
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* g | has several chars ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_MULTIPLE_CHARS
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* s | has a terminal ? 1 bit, 1 = yes, 0 = no : FLAG_IS_TERMINAL
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* | reserved 1 bit, 1 = yes, 0 = no
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* | has bigrams ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_BIGRAMS
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*
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* c | IF FLAG_HAS_MULTIPLE_CHARS
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* h | char, char, char, char n * (1 or 3 bytes) : use CharGroupInfo for i/o helpers
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* a | end 1 byte, = 0
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* r | ELSE
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* s | char 1 or 3 bytes
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* | END
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*
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* f |
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* r | IF FLAG_IS_TERMINAL
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* e | frequency 1 byte
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* q |
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*
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* c | IF 00 = FLAG_GROUP_ADDRESS_TYPE_NOADDRESS = addressType
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* h | // nothing
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* i | ELSIF 01 = FLAG_GROUP_ADDRESS_TYPE_ONEBYTE == addressType
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* l | children address, 1 byte
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* d | ELSIF 10 = FLAG_GROUP_ADDRESS_TYPE_TWOBYTES == addressType
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* r | children address, 2 bytes
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* e | ELSE // 11 = FLAG_GROUP_ADDRESS_TYPE_THREEBYTES = addressType
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* n | children address, 3 bytes
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* A | END
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* d
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* dress
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*
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* | IF FLAG_IS_TERMINAL && FLAG_HAS_BIGRAMS
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* | bigrams address list
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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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* bigram and shortcut address list is:
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* <flags> = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_ATTRIBUTE_HAS_NEXT
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* | addressSign = 1 bit, : FLAG_ATTRIBUTE_OFFSET_NEGATIVE
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* | 1 = must take -address, 0 = must take +address
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* | xx : mask with MASK_ATTRIBUTE_ADDRESS_TYPE
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* | addressFormat = 2 bits, 00 = unused : FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE
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* | 01 = 1 byte : FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE
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* | 10 = 2 bytes : FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES
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* | 11 = 3 bytes : FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES
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* | 4 bits : frequency : mask with FLAG_ATTRIBUTE_FREQUENCY
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* <address> | IF (01 == FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE == addressFormat)
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* | read 1 byte, add top 4 bits
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* | ELSIF (10 == FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES == addressFormat)
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* | read 2 bytes, add top 4 bits
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* | ELSE // 11 == FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES == addressFormat
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* | read 3 bytes, add top 4 bits
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* | END
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* | if (FLAG_ATTRIBUTE_OFFSET_NEGATIVE) then address = -address
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* if (FLAG_ATTRIBUTE_HAS_NET) goto bigram_and_shortcut_address_list_is
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*
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*/
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private static final int MAGIC_NUMBER = 0x78B1;
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private static final int VERSION = 1;
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private static final int MAXIMUM_SUPPORTED_VERSION = VERSION;
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// No options yet, reserved for future use.
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private static final int OPTIONS = 0;
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// TODO: Make this value adaptative to content data, store it in the header, and
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// use it in the reading code.
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private static final int MAX_WORD_LENGTH = 48;
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private static final int MASK_GROUP_ADDRESS_TYPE = 0xC0;
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private static final int FLAG_GROUP_ADDRESS_TYPE_NOADDRESS = 0x00;
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private static final int FLAG_GROUP_ADDRESS_TYPE_ONEBYTE = 0x40;
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private static final int FLAG_GROUP_ADDRESS_TYPE_TWOBYTES = 0x80;
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private static final int FLAG_GROUP_ADDRESS_TYPE_THREEBYTES = 0xC0;
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private static final int FLAG_HAS_MULTIPLE_CHARS = 0x20;
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private static final int FLAG_IS_TERMINAL = 0x10;
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private static final int FLAG_HAS_BIGRAMS = 0x04;
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private static final int FLAG_ATTRIBUTE_HAS_NEXT = 0x80;
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private static final int FLAG_ATTRIBUTE_OFFSET_NEGATIVE = 0x40;
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private static final int MASK_ATTRIBUTE_ADDRESS_TYPE = 0x30;
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private static final int FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE = 0x10;
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private static final int FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES = 0x20;
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private static final int FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES = 0x30;
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private static final int FLAG_ATTRIBUTE_FREQUENCY = 0x0F;
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private static final int GROUP_CHARACTERS_TERMINATOR = 0x1F;
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private static final int GROUP_COUNT_SIZE = 1;
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private static final int GROUP_TERMINATOR_SIZE = 1;
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private static final int GROUP_FLAGS_SIZE = 1;
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private static final int GROUP_FREQUENCY_SIZE = 1;
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private static final int GROUP_MAX_ADDRESS_SIZE = 3;
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private static final int GROUP_ATTRIBUTE_FLAGS_SIZE = 1;
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private static final int GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE = 3;
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private static final int NO_CHILDREN_ADDRESS = Integer.MIN_VALUE;
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private static final int INVALID_CHARACTER = -1;
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// Limiting to 127 for upward compatibility
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// TODO: implement a scheme to be able to shoot 256 chargroups in a node
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private static final int MAX_CHARGROUPS_IN_A_NODE = 127;
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private static final int MAX_TERMINAL_FREQUENCY = 255;
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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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private static 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(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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private static int getCharSize(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 (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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private 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 characters the character 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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private static int writeCharArray(int[] characters, byte[] buffer, int index) {
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for (int character : characters) {
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if (1 == getCharSize(character)) {
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buffer[index++] = (byte)character;
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} else {
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buffer[index++] = (byte)(0xFF & (character >> 16));
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buffer[index++] = (byte)(0xFF & (character >> 8));
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buffer[index++] = (byte)(0xFF & character);
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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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* Reads a character from the file.
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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 source the file, positioned over an encoded character.
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* @return the character code.
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*/
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private static int readChar(RandomAccessFile source) throws IOException {
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int character = source.readUnsignedByte();
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if (!fitsOnOneByte(character)) {
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if (GROUP_CHARACTERS_TERMINATOR == character)
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return INVALID_CHARACTER;
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character <<= 16;
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character += source.readUnsignedShort();
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}
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return character;
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}
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}
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/**
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* Compute the binary size of the character array in a group
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*
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* If only one character, this is the size of this character. If many, it's the sum of their
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* sizes + 1 byte for the terminator.
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*
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* @param group the group
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* @return the size of the char array, including the terminator if any
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*/
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private static int getGroupCharactersSize(CharGroup group) {
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int size = CharEncoding.getCharArraySize(group.mChars);
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if (group.hasSeveralChars()) size += GROUP_TERMINATOR_SIZE;
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return size;
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}
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/**
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* Compute the maximum size of a CharGroup, assuming 3-byte addresses for everything.
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*
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* @param group the CharGroup to compute the size of.
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* @return the maximum size of the group.
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*/
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private static int getCharGroupMaximumSize(CharGroup group) {
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int size = getGroupCharactersSize(group) + GROUP_FLAGS_SIZE;
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// If terminal, one byte for the frequency
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if (group.isTerminal()) size += GROUP_FREQUENCY_SIZE;
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size += GROUP_MAX_ADDRESS_SIZE; // For children address
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if (null != group.mBigrams) {
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for (WeightedString bigram : group.mBigrams) {
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size += GROUP_ATTRIBUTE_FLAGS_SIZE + GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE;
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}
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}
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return size;
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}
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/**
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* Compute the maximum size of a node, assuming 3-byte addresses for everything, and caches
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* it in the 'actualSize' member of the node.
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*
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* @param node the node to compute the maximum size of.
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*/
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private static void setNodeMaximumSize(Node node) {
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int size = GROUP_COUNT_SIZE;
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for (CharGroup g : node.mData) {
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final int groupSize = getCharGroupMaximumSize(g);
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g.mCachedSize = groupSize;
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size += groupSize;
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}
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node.mCachedSize = size;
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}
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/**
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* Helper method to hide the actual value of the no children address.
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*/
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private static boolean hasChildrenAddress(int address) {
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return NO_CHILDREN_ADDRESS != address;
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}
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/**
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* Compute the size, in bytes, that an address will occupy.
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*
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* This can be used either for children addresses (which are always positive) or for
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* attribute, which may be positive or negative but
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* store their sign bit separately.
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*
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* @param address the address
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* @return the byte size.
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*/
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private static int getByteSize(int address) {
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assert(address < 0x1000000);
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if (!hasChildrenAddress(address)) {
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return 0;
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} else if (Math.abs(address) < 0x100) {
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return 1;
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} else if (Math.abs(address) < 0x10000) {
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return 2;
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} else {
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return 3;
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}
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}
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// End utility methods.
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// This method is responsible for finding a nice ordering of the nodes that favors run-time
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// cache performance and dictionary size.
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/* package for tests */ static ArrayList<Node> flattenTree(Node root) {
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final int treeSize = FusionDictionary.countCharGroups(root);
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MakedictLog.i("Counted nodes : " + treeSize);
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final ArrayList<Node> flatTree = new ArrayList<Node>(treeSize);
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return flattenTreeInner(flatTree, root);
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}
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private static ArrayList<Node> flattenTreeInner(ArrayList<Node> list, Node node) {
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// Removing the node is necessary if the tails are merged, because we would then
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// add the same node several times when we only want it once. A number of places in
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// the code also depends on any node being only once in the list.
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// Merging tails can only be done if there are no attributes. Searching for attributes
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// in LatinIME code depends on a total breadth-first ordering, which merging tails
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// breaks. If there are no attributes, it should be fine (and reduce the file size)
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// to merge tails, and the following step would be necessary.
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// If eventually the code runs on Android, searching through the whole array each time
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// may be a performance concern.
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list.remove(node);
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list.add(node);
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final ArrayList<CharGroup> branches = node.mData;
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final int nodeSize = branches.size();
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for (CharGroup group : branches) {
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if (null != group.mChildren) flattenTreeInner(list, group.mChildren);
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}
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return list;
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}
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/**
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* Finds the absolute address of a word in the dictionary.
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*
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* @param dict the dictionary in which to search.
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* @param word the word we are searching for.
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* @return the word address. If it is not found, an exception is thrown.
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*/
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private static int findAddressOfWord(final FusionDictionary dict, final String word) {
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return FusionDictionary.findWordInTree(dict.mRoot, word).mCachedAddress;
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}
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/**
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* Computes the actual node size, based on the cached addresses of the children nodes.
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*
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* Each node stores its tentative address. During dictionary address computing, these
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* are not final, but they can be used to compute the node size (the node size depends
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* on the address of the children because the number of bytes necessary to store an
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* address depends on its numeric value.
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*
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* @param node the node to compute the size of.
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* @param dict the dictionary in which the word/attributes are to be found.
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*/
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private static void computeActualNodeSize(Node node, FusionDictionary dict) {
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int size = GROUP_COUNT_SIZE;
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for (CharGroup group : node.mData) {
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int groupSize = GROUP_FLAGS_SIZE + getGroupCharactersSize(group);
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if (group.isTerminal()) groupSize += GROUP_FREQUENCY_SIZE;
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if (null != group.mChildren) {
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final int offsetBasePoint= groupSize + node.mCachedAddress + size;
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final int offset = group.mChildren.mCachedAddress - offsetBasePoint;
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groupSize += getByteSize(offset);
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}
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if (null != group.mBigrams) {
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for (WeightedString bigram : group.mBigrams) {
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final int offsetBasePoint = groupSize + node.mCachedAddress + size
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+ GROUP_FLAGS_SIZE;
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final int addressOfBigram = findAddressOfWord(dict, bigram.mWord);
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final int offset = addressOfBigram - offsetBasePoint;
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groupSize += getByteSize(offset) + GROUP_FLAGS_SIZE;
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}
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}
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group.mCachedSize = groupSize;
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size += groupSize;
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}
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node.mCachedSize = size;
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}
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/**
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* Computes the byte size of a list of nodes and updates each node cached position.
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*
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* @param flatNodes the array of nodes.
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* @return the byte size of the entire stack.
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*/
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private static int stackNodes(ArrayList<Node> flatNodes) {
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int nodeOffset = 0;
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for (Node n : flatNodes) {
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n.mCachedAddress = nodeOffset;
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int groupOffset = 0;
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for (CharGroup g : n.mData) {
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g.mCachedAddress = GROUP_COUNT_SIZE + nodeOffset + groupOffset;
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groupOffset += g.mCachedSize;
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}
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if (groupOffset + GROUP_COUNT_SIZE != n.mCachedSize) {
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throw new RuntimeException("Bug : Stored and computed node size differ");
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}
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nodeOffset += n.mCachedSize;
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}
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return nodeOffset;
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}
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/**
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* Compute the addresses and sizes of an ordered node array.
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*
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* This method takes a node array and will update its cached address and size values
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* so that they can be written into a file. It determines the smallest size each of the
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* nodes can be given the addresses of its children and attributes, and store that into
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* each node.
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* The order of the node is given by the order of the array. This method makes no effort
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* to find a good order; it only mechanically computes the size this order results in.
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*
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* @param dict the dictionary
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* @param flatNodes the ordered array of nodes
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* @return the same array it was passed. The nodes have been updated for address and size.
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*/
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private static ArrayList<Node> computeAddresses(FusionDictionary dict,
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ArrayList<Node> flatNodes) {
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// First get the worst sizes and offsets
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for (Node n : flatNodes) setNodeMaximumSize(n);
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final int offset = stackNodes(flatNodes);
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MakedictLog.i("Compressing the array addresses. Original size : " + offset);
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MakedictLog.i("(Recursively seen size : " + offset + ")");
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int passes = 0;
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boolean changesDone = false;
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do {
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changesDone = false;
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for (Node n : flatNodes) {
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final int oldNodeSize = n.mCachedSize;
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computeActualNodeSize(n, dict);
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final int newNodeSize = n.mCachedSize;
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if (oldNodeSize < newNodeSize) throw new RuntimeException("Increased size ?!");
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if (oldNodeSize != newNodeSize) changesDone = true;
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}
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stackNodes(flatNodes);
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++passes;
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} while (changesDone);
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final Node lastNode = flatNodes.get(flatNodes.size() - 1);
|
|
MakedictLog.i("Compression complete in " + passes + " passes.");
|
|
MakedictLog.i("After address compression : "
|
|
+ (lastNode.mCachedAddress + lastNode.mCachedSize));
|
|
|
|
return flatNodes;
|
|
}
|
|
|
|
/**
|
|
* Sanity-checking method.
|
|
*
|
|
* This method checks an array of node for juxtaposition, that is, it will do
|
|
* nothing if each node's cached address is actually the previous node's address
|
|
* plus the previous node's size.
|
|
* If this is not the case, it will throw an exception.
|
|
*
|
|
* @param array the array node to check
|
|
*/
|
|
private static void checkFlatNodeArray(ArrayList<Node> array) {
|
|
int offset = 0;
|
|
int index = 0;
|
|
for (Node n : array) {
|
|
if (n.mCachedAddress != offset) {
|
|
throw new RuntimeException("Wrong address for node " + index
|
|
+ " : expected " + offset + ", got " + n.mCachedAddress);
|
|
}
|
|
++index;
|
|
offset += n.mCachedSize;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Helper method to write a variable-size address to a file.
|
|
*
|
|
* @param buffer the buffer to write to.
|
|
* @param index the index in the buffer to write the address to.
|
|
* @param address the address to write.
|
|
* @return the size in bytes the address actually took.
|
|
*/
|
|
private static int writeVariableAddress(byte[] buffer, int index, int address) {
|
|
switch (getByteSize(address)) {
|
|
case 1:
|
|
buffer[index++] = (byte)address;
|
|
return 1;
|
|
case 2:
|
|
buffer[index++] = (byte)(0xFF & (address >> 8));
|
|
buffer[index++] = (byte)(0xFF & address);
|
|
return 2;
|
|
case 3:
|
|
buffer[index++] = (byte)(0xFF & (address >> 16));
|
|
buffer[index++] = (byte)(0xFF & (address >> 8));
|
|
buffer[index++] = (byte)(0xFF & address);
|
|
return 3;
|
|
case 0:
|
|
return 0;
|
|
default:
|
|
throw new RuntimeException("Address " + address + " has a strange size");
|
|
}
|
|
}
|
|
|
|
private static byte makeCharGroupFlags(final CharGroup group, final int groupAddress,
|
|
final int childrenOffset) {
|
|
byte flags = 0;
|
|
if (group.mChars.length > 1) flags |= FLAG_HAS_MULTIPLE_CHARS;
|
|
if (group.mFrequency >= 0) {
|
|
flags |= FLAG_IS_TERMINAL;
|
|
}
|
|
if (null != group.mChildren) {
|
|
switch (getByteSize(childrenOffset)) {
|
|
case 1:
|
|
flags |= FLAG_GROUP_ADDRESS_TYPE_ONEBYTE;
|
|
break;
|
|
case 2:
|
|
flags |= FLAG_GROUP_ADDRESS_TYPE_TWOBYTES;
|
|
break;
|
|
case 3:
|
|
flags |= FLAG_GROUP_ADDRESS_TYPE_THREEBYTES;
|
|
break;
|
|
default:
|
|
throw new RuntimeException("Node with a strange address");
|
|
}
|
|
}
|
|
if (null != group.mBigrams) flags |= FLAG_HAS_BIGRAMS;
|
|
return flags;
|
|
}
|
|
|
|
/**
|
|
* Makes the flag value for an attribute.
|
|
*
|
|
* @param more whether there are more attributes after this one.
|
|
* @param offset the offset of the attribute.
|
|
* @param frequency the frequency of the attribute, 0..15
|
|
* @return the flags
|
|
*/
|
|
private static final int makeAttributeFlags(final boolean more, final int offset,
|
|
final int frequency) {
|
|
int bigramFlags = (more ? FLAG_ATTRIBUTE_HAS_NEXT : 0)
|
|
+ (offset < 0 ? FLAG_ATTRIBUTE_OFFSET_NEGATIVE : 0);
|
|
switch (getByteSize(offset)) {
|
|
case 1:
|
|
bigramFlags |= FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE;
|
|
break;
|
|
case 2:
|
|
bigramFlags |= FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES;
|
|
break;
|
|
case 3:
|
|
bigramFlags |= FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES;
|
|
break;
|
|
default:
|
|
throw new RuntimeException("Strange offset size");
|
|
}
|
|
bigramFlags += frequency & FLAG_ATTRIBUTE_FREQUENCY;
|
|
return bigramFlags;
|
|
}
|
|
|
|
/**
|
|
* Write a node to memory. The node is expected to have its final position cached.
|
|
*
|
|
* This can be an empty map, but the more is inside the faster the lookups will be. It can
|
|
* be carried on as long as nodes do not move.
|
|
*
|
|
* @param dict the dictionary the node is a part of (for relative offsets).
|
|
* @param buffer the memory buffer to write to.
|
|
* @param node the node to write.
|
|
* @return the address of the END of the node.
|
|
*/
|
|
private static int writePlacedNode(FusionDictionary dict, byte[] buffer, Node node) {
|
|
int index = node.mCachedAddress;
|
|
|
|
final int size = node.mData.size();
|
|
if (size > MAX_CHARGROUPS_IN_A_NODE)
|
|
throw new RuntimeException("A node has a group count over 127 (" + size + ").");
|
|
|
|
buffer[index++] = (byte)size;
|
|
int groupAddress = index;
|
|
for (int i = 0; i < size; ++i) {
|
|
CharGroup group = node.mData.get(i);
|
|
if (index != group.mCachedAddress) throw new RuntimeException("Bug: write index is not "
|
|
+ "the same as the cached address of the group");
|
|
groupAddress += GROUP_FLAGS_SIZE + getGroupCharactersSize(group);
|
|
// Sanity checks.
|
|
if (group.mFrequency > MAX_TERMINAL_FREQUENCY) {
|
|
throw new RuntimeException("A node has a frequency > " + MAX_TERMINAL_FREQUENCY
|
|
+ " : " + group.mFrequency);
|
|
}
|
|
if (group.mFrequency >= 0) groupAddress += GROUP_FREQUENCY_SIZE;
|
|
final int childrenOffset = null == group.mChildren
|
|
? NO_CHILDREN_ADDRESS : group.mChildren.mCachedAddress - groupAddress;
|
|
byte flags = makeCharGroupFlags(group, groupAddress, childrenOffset);
|
|
buffer[index++] = flags;
|
|
index = CharEncoding.writeCharArray(group.mChars, buffer, index);
|
|
if (group.hasSeveralChars()) {
|
|
buffer[index++] = GROUP_CHARACTERS_TERMINATOR;
|
|
}
|
|
if (group.mFrequency >= 0) {
|
|
buffer[index++] = (byte) group.mFrequency;
|
|
}
|
|
final int shift = writeVariableAddress(buffer, index, childrenOffset);
|
|
index += shift;
|
|
groupAddress += shift;
|
|
|
|
// Write bigrams
|
|
if (null != group.mBigrams) {
|
|
int remainingBigrams = group.mBigrams.size();
|
|
for (WeightedString bigram : group.mBigrams) {
|
|
boolean more = remainingBigrams > 1;
|
|
final int addressOfBigram = findAddressOfWord(dict, bigram.mWord);
|
|
++groupAddress;
|
|
final int offset = addressOfBigram - groupAddress;
|
|
int bigramFlags = makeAttributeFlags(more, offset, bigram.mFrequency);
|
|
buffer[index++] = (byte)bigramFlags;
|
|
final int bigramShift = writeVariableAddress(buffer, index, Math.abs(offset));
|
|
index += bigramShift;
|
|
groupAddress += bigramShift;
|
|
--remainingBigrams;
|
|
}
|
|
}
|
|
|
|
}
|
|
if (index != node.mCachedAddress + node.mCachedSize) throw new RuntimeException(
|
|
"Not the same size : written "
|
|
+ (index - node.mCachedAddress) + " bytes out of a node that should have "
|
|
+ node.mCachedSize + " bytes");
|
|
return index;
|
|
}
|
|
|
|
/**
|
|
* Dumps a collection of useful statistics about a node array.
|
|
*
|
|
* This prints purely informative stuff, like the total estimated file size, the
|
|
* number of nodes, of character groups, the repartition of each address size, etc
|
|
*
|
|
* @param nodes the node array.
|
|
*/
|
|
private static void showStatistics(ArrayList<Node> nodes) {
|
|
int firstTerminalAddress = Integer.MAX_VALUE;
|
|
int lastTerminalAddress = Integer.MIN_VALUE;
|
|
int size = 0;
|
|
int charGroups = 0;
|
|
int maxGroups = 0;
|
|
int maxRuns = 0;
|
|
for (Node n : nodes) {
|
|
if (maxGroups < n.mData.size()) maxGroups = n.mData.size();
|
|
for (CharGroup cg : n.mData) {
|
|
++charGroups;
|
|
if (cg.mChars.length > maxRuns) maxRuns = cg.mChars.length;
|
|
if (cg.mFrequency >= 0) {
|
|
if (n.mCachedAddress < firstTerminalAddress)
|
|
firstTerminalAddress = n.mCachedAddress;
|
|
if (n.mCachedAddress > lastTerminalAddress)
|
|
lastTerminalAddress = n.mCachedAddress;
|
|
}
|
|
}
|
|
if (n.mCachedAddress + n.mCachedSize > size) size = n.mCachedAddress + n.mCachedSize;
|
|
}
|
|
final int[] groupCounts = new int[maxGroups + 1];
|
|
final int[] runCounts = new int[maxRuns + 1];
|
|
for (Node n : nodes) {
|
|
++groupCounts[n.mData.size()];
|
|
for (CharGroup cg : n.mData) {
|
|
++runCounts[cg.mChars.length];
|
|
}
|
|
}
|
|
|
|
MakedictLog.i("Statistics:\n"
|
|
+ " total file size " + size + "\n"
|
|
+ " " + nodes.size() + " nodes\n"
|
|
+ " " + charGroups + " groups (" + ((float)charGroups / nodes.size())
|
|
+ " groups per node)\n"
|
|
+ " first terminal at " + firstTerminalAddress + "\n"
|
|
+ " last terminal at " + lastTerminalAddress + "\n"
|
|
+ " Group stats : max = " + maxGroups);
|
|
for (int i = 0; i < groupCounts.length; ++i) {
|
|
MakedictLog.i(" " + i + " : " + groupCounts[i]);
|
|
}
|
|
MakedictLog.i(" Character run stats : max = " + maxRuns);
|
|
for (int i = 0; i < runCounts.length; ++i) {
|
|
MakedictLog.i(" " + i + " : " + runCounts[i]);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Dumps a FusionDictionary to a file.
|
|
*
|
|
* This is the public entry point to write a dictionary to a file.
|
|
*
|
|
* @param destination the stream to write the binary data to.
|
|
* @param dict the dictionary to write.
|
|
*/
|
|
public static void writeDictionaryBinary(OutputStream destination, FusionDictionary dict)
|
|
throws IOException {
|
|
|
|
// Addresses are limited to 3 bytes, so we'll just make a 16MB buffer. Since addresses
|
|
// can be relative to each node, the structure itself is not limited to 16MB at all, but
|
|
// I doubt this will ever be shot. If it is, deciding the order of the nodes becomes
|
|
// a quite complicated problem, because though the dictionary itself does not have a
|
|
// size limit, each node 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.
|
|
// Anyway, to make a dictionary bigger than 16MB just increase the size of this buffer.
|
|
final byte[] buffer = new byte[1 << 24];
|
|
int index = 0;
|
|
|
|
// Magic number in big-endian order.
|
|
buffer[index++] = (byte) (0xFF & (MAGIC_NUMBER >> 8));
|
|
buffer[index++] = (byte) (0xFF & MAGIC_NUMBER);
|
|
// Dictionary version.
|
|
buffer[index++] = (byte) (0xFF & VERSION);
|
|
// Options flags
|
|
buffer[index++] = (byte) (0xFF & (OPTIONS >> 8));
|
|
buffer[index++] = (byte) (0xFF & OPTIONS);
|
|
|
|
// Should we include the locale and title of the dictionary ?
|
|
|
|
destination.write(buffer, 0, index);
|
|
index = 0;
|
|
|
|
// Leave the choice of the optimal node order to the flattenTree function.
|
|
MakedictLog.i("Flattening the tree...");
|
|
ArrayList<Node> flatNodes = flattenTree(dict.mRoot);
|
|
|
|
MakedictLog.i("Computing addresses...");
|
|
computeAddresses(dict, flatNodes);
|
|
MakedictLog.i("Checking array...");
|
|
checkFlatNodeArray(flatNodes);
|
|
|
|
MakedictLog.i("Writing file...");
|
|
int dataEndOffset = 0;
|
|
for (Node n : flatNodes) {
|
|
dataEndOffset = writePlacedNode(dict, buffer, n);
|
|
}
|
|
|
|
showStatistics(flatNodes);
|
|
|
|
destination.write(buffer, 0, dataEndOffset);
|
|
|
|
destination.close();
|
|
MakedictLog.i("Done");
|
|
}
|
|
|
|
|
|
// Input methods: Read a binary dictionary to memory.
|
|
// readDictionaryBinary is the public entry point for them.
|
|
|
|
static final int[] characterBuffer = new int[MAX_WORD_LENGTH];
|
|
private static CharGroupInfo readCharGroup(RandomAccessFile source,
|
|
final int originalGroupAddress) throws IOException {
|
|
int addressPointer = originalGroupAddress;
|
|
final int flags = source.readUnsignedByte();
|
|
++addressPointer;
|
|
final int characters[];
|
|
if (0 != (flags & FLAG_HAS_MULTIPLE_CHARS)) {
|
|
int index = 0;
|
|
int character = CharEncoding.readChar(source);
|
|
addressPointer += CharEncoding.getCharSize(character);
|
|
while (-1 != character) {
|
|
characterBuffer[index++] = character;
|
|
character = CharEncoding.readChar(source);
|
|
addressPointer += CharEncoding.getCharSize(character);
|
|
}
|
|
characters = Arrays.copyOfRange(characterBuffer, 0, index);
|
|
} else {
|
|
final int character = CharEncoding.readChar(source);
|
|
addressPointer += CharEncoding.getCharSize(character);
|
|
characters = new int[] { character };
|
|
}
|
|
final int frequency;
|
|
if (0 != (FLAG_IS_TERMINAL & flags)) {
|
|
++addressPointer;
|
|
frequency = source.readUnsignedByte();
|
|
} else {
|
|
frequency = CharGroup.NOT_A_TERMINAL;
|
|
}
|
|
int childrenAddress = addressPointer;
|
|
switch (flags & MASK_GROUP_ADDRESS_TYPE) {
|
|
case FLAG_GROUP_ADDRESS_TYPE_ONEBYTE:
|
|
childrenAddress += source.readUnsignedByte();
|
|
addressPointer += 1;
|
|
break;
|
|
case FLAG_GROUP_ADDRESS_TYPE_TWOBYTES:
|
|
childrenAddress += source.readUnsignedShort();
|
|
addressPointer += 2;
|
|
break;
|
|
case FLAG_GROUP_ADDRESS_TYPE_THREEBYTES:
|
|
childrenAddress += (source.readUnsignedByte() << 16) + source.readUnsignedShort();
|
|
addressPointer += 3;
|
|
break;
|
|
case FLAG_GROUP_ADDRESS_TYPE_NOADDRESS:
|
|
default:
|
|
childrenAddress = NO_CHILDREN_ADDRESS;
|
|
break;
|
|
}
|
|
ArrayList<PendingAttribute> bigrams = null;
|
|
if (0 != (flags & FLAG_HAS_BIGRAMS)) {
|
|
bigrams = new ArrayList<PendingAttribute>();
|
|
boolean more = true;
|
|
while (more) {
|
|
int bigramFlags = source.readUnsignedByte();
|
|
++addressPointer;
|
|
more = (0 != (bigramFlags & FLAG_ATTRIBUTE_HAS_NEXT));
|
|
final int sign = 0 == (bigramFlags & FLAG_ATTRIBUTE_OFFSET_NEGATIVE) ? 1 : -1;
|
|
int bigramAddress = addressPointer;
|
|
switch (bigramFlags & MASK_ATTRIBUTE_ADDRESS_TYPE) {
|
|
case FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE:
|
|
bigramAddress += sign * source.readUnsignedByte();
|
|
addressPointer += 1;
|
|
break;
|
|
case FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES:
|
|
bigramAddress += sign * source.readUnsignedShort();
|
|
addressPointer += 2;
|
|
break;
|
|
case FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES:
|
|
final int offset = ((source.readUnsignedByte() << 16)
|
|
+ source.readUnsignedShort());
|
|
bigramAddress += sign * offset;
|
|
addressPointer += 3;
|
|
break;
|
|
default:
|
|
throw new RuntimeException("Has attribute with no address");
|
|
}
|
|
bigrams.add(new PendingAttribute(bigramFlags & FLAG_ATTRIBUTE_FREQUENCY,
|
|
bigramAddress));
|
|
}
|
|
}
|
|
return new CharGroupInfo(originalGroupAddress, addressPointer, flags, characters, frequency,
|
|
childrenAddress, bigrams);
|
|
}
|
|
|
|
/**
|
|
* Finds, as a string, the word at the address passed as an argument.
|
|
*
|
|
* @param source the file to read from.
|
|
* @param headerSize the size of the header.
|
|
* @param address the address to seek.
|
|
* @return the word, as a string.
|
|
* @throws IOException if the file can't be read.
|
|
*/
|
|
private static String getWordAtAddress(RandomAccessFile source, long headerSize,
|
|
int address) throws IOException {
|
|
final long originalPointer = source.getFilePointer();
|
|
source.seek(headerSize);
|
|
final int count = source.readUnsignedByte();
|
|
int groupOffset = 1; // 1 for the group count
|
|
final StringBuilder builder = new StringBuilder();
|
|
String result = null;
|
|
|
|
CharGroupInfo last = null;
|
|
for (int i = count - 1; i >= 0; --i) {
|
|
CharGroupInfo info = readCharGroup(source, groupOffset);
|
|
groupOffset = info.mEndAddress;
|
|
if (info.mOriginalAddress == address) {
|
|
builder.append(new String(info.mCharacters, 0, info.mCharacters.length));
|
|
result = builder.toString();
|
|
break; // and return
|
|
}
|
|
if (hasChildrenAddress(info.mChildrenAddress)) {
|
|
if (info.mChildrenAddress > address) {
|
|
if (null == last) continue;
|
|
builder.append(new String(last.mCharacters, 0, last.mCharacters.length));
|
|
source.seek(last.mChildrenAddress + headerSize);
|
|
groupOffset = last.mChildrenAddress + 1;
|
|
i = source.readUnsignedByte();
|
|
last = null;
|
|
continue;
|
|
}
|
|
last = info;
|
|
}
|
|
if (0 == i && hasChildrenAddress(last.mChildrenAddress)) {
|
|
builder.append(new String(last.mCharacters, 0, last.mCharacters.length));
|
|
source.seek(last.mChildrenAddress + headerSize);
|
|
groupOffset = last.mChildrenAddress + 1;
|
|
i = source.readUnsignedByte();
|
|
last = null;
|
|
continue;
|
|
}
|
|
}
|
|
source.seek(originalPointer);
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* Reads a single node from a binary file.
|
|
*
|
|
* This methods reads the file at the current position of its file pointer. A node is
|
|
* fully expected to start at the current position.
|
|
* This will recursively read other nodes into the structure, populating the reverse
|
|
* maps on the fly and using them to keep track of already read nodes.
|
|
*
|
|
* @param source the data file, correctly positioned at the start of a node.
|
|
* @param headerSize the size, in bytes, of the file header.
|
|
* @param reverseNodeMap a mapping from addresses to already read nodes.
|
|
* @param reverseGroupMap a mapping from addresses to already read character groups.
|
|
* @return the read node with all his children already read.
|
|
*/
|
|
private static Node readNode(RandomAccessFile source, long headerSize,
|
|
Map<Integer, Node> reverseNodeMap, Map<Integer, CharGroup> reverseGroupMap)
|
|
throws IOException {
|
|
final int nodeOrigin = (int)(source.getFilePointer() - headerSize);
|
|
final int count = source.readUnsignedByte();
|
|
final ArrayList<CharGroup> nodeContents = new ArrayList<CharGroup>();
|
|
int groupOffset = nodeOrigin + 1; // 1 byte for the group count
|
|
for (int i = count; i > 0; --i) {
|
|
CharGroupInfo info = readCharGroup(source, groupOffset);
|
|
ArrayList<WeightedString> bigrams = null;
|
|
if (null != info.mBigrams) {
|
|
bigrams = new ArrayList<WeightedString>();
|
|
for (PendingAttribute bigram : info.mBigrams) {
|
|
final String word = getWordAtAddress(source, headerSize, bigram.mAddress);
|
|
bigrams.add(new WeightedString(word, bigram.mFrequency));
|
|
}
|
|
}
|
|
if (hasChildrenAddress(info.mChildrenAddress)) {
|
|
Node children = reverseNodeMap.get(info.mChildrenAddress);
|
|
if (null == children) {
|
|
final long currentPosition = source.getFilePointer();
|
|
source.seek(info.mChildrenAddress + headerSize);
|
|
children = readNode(source, headerSize, reverseNodeMap, reverseGroupMap);
|
|
source.seek(currentPosition);
|
|
}
|
|
nodeContents.add(
|
|
new CharGroup(info.mCharacters, bigrams, info.mFrequency,
|
|
children));
|
|
} else {
|
|
nodeContents.add(
|
|
new CharGroup(info.mCharacters, bigrams, info.mFrequency));
|
|
}
|
|
groupOffset = info.mEndAddress;
|
|
}
|
|
final Node node = new Node(nodeContents);
|
|
node.mCachedAddress = nodeOrigin;
|
|
reverseNodeMap.put(node.mCachedAddress, node);
|
|
return node;
|
|
}
|
|
|
|
/**
|
|
* Reads a random access file and returns the memory representation of the dictionary.
|
|
*
|
|
* This high-level method takes a binary file and reads its contents, populating a
|
|
* FusionDictionary structure. The optional dict argument is an existing dictionary to
|
|
* which words from the file should be added. If it is null, a new dictionary is created.
|
|
*
|
|
* @param source the file to read.
|
|
* @param dict an optional dictionary to add words to, or null.
|
|
* @return the created (or merged) dictionary.
|
|
*/
|
|
public static FusionDictionary readDictionaryBinary(RandomAccessFile source,
|
|
FusionDictionary dict) throws IOException, UnsupportedFormatException {
|
|
// Check magic number
|
|
final int magic = source.readUnsignedShort();
|
|
if (MAGIC_NUMBER != magic) {
|
|
throw new UnsupportedFormatException("The magic number in this file does not match "
|
|
+ "the expected value");
|
|
}
|
|
|
|
// Check file version
|
|
final int version = source.readUnsignedByte();
|
|
if (version > MAXIMUM_SUPPORTED_VERSION) {
|
|
throw new UnsupportedFormatException("This file has version " + version
|
|
+ ", but this implementation does not support versions above "
|
|
+ MAXIMUM_SUPPORTED_VERSION);
|
|
}
|
|
|
|
// Read options
|
|
source.readUnsignedShort();
|
|
|
|
long headerSize = source.getFilePointer();
|
|
Map<Integer, Node> reverseNodeMapping = new TreeMap<Integer, Node>();
|
|
Map<Integer, CharGroup> reverseGroupMapping = new TreeMap<Integer, CharGroup>();
|
|
final Node root = readNode(source, headerSize, reverseNodeMapping, reverseGroupMapping);
|
|
|
|
FusionDictionary newDict = new FusionDictionary(root,
|
|
new FusionDictionary.DictionaryOptions());
|
|
if (null != dict) {
|
|
for (Word w : dict) {
|
|
newDict.add(w.mWord, w.mFrequency, w.mBigrams);
|
|
}
|
|
}
|
|
|
|
return newDict;
|
|
}
|
|
|
|
/**
|
|
* Basic test to find out whether the file is a binary dictionary or not.
|
|
*
|
|
* Concretely this only tests the magic number.
|
|
*
|
|
* @param filename The name of the file to test.
|
|
* @return true if it's a binary dictionary, false otherwise
|
|
*/
|
|
public static boolean isBinaryDictionary(String filename) {
|
|
try {
|
|
RandomAccessFile f = new RandomAccessFile(filename, "r");
|
|
return MAGIC_NUMBER == f.readUnsignedShort();
|
|
} catch (FileNotFoundException e) {
|
|
return false;
|
|
} catch (IOException e) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|