| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.inputmethod.latin.makedict; |
| |
| import com.android.inputmethod.annotations.UsedForTesting; |
| import com.android.inputmethod.latin.Constants; |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.Date; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| |
| /** |
| * A dictionary that can fusion heads and tails of words for more compression. |
| */ |
| @UsedForTesting |
| public final class FusionDictionary implements Iterable<Word> { |
| private static final boolean DBG = MakedictLog.DBG; |
| |
| /** |
| * A node of the dictionary, containing several CharGroups. |
| * |
| * A node is but an ordered array of CharGroups, which essentially contain all the |
| * real information. |
| * This class also contains fields to cache size and address, to help with binary |
| * generation. |
| */ |
| public static final class Node { |
| ArrayList<CharGroup> mData; |
| // To help with binary generation |
| int mCachedSize = Integer.MIN_VALUE; |
| int mCachedAddress = Integer.MIN_VALUE; |
| int mCachedParentAddress = 0; |
| |
| public Node() { |
| mData = new ArrayList<CharGroup>(); |
| } |
| public Node(ArrayList<CharGroup> data) { |
| mData = data; |
| } |
| } |
| |
| /** |
| * A string with a frequency. |
| * |
| * This represents an "attribute", that is either a bigram or a shortcut. |
| */ |
| public static final class WeightedString { |
| public final String mWord; |
| public int mFrequency; |
| public WeightedString(String word, int frequency) { |
| mWord = word; |
| mFrequency = frequency; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Arrays.hashCode(new Object[] { mWord, mFrequency }); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (o == this) return true; |
| if (!(o instanceof WeightedString)) return false; |
| WeightedString w = (WeightedString)o; |
| return mWord.equals(w.mWord) && mFrequency == w.mFrequency; |
| } |
| } |
| |
| /** |
| * A group of characters, with a frequency, shortcut targets, bigrams, and children. |
| * |
| * This is the central class of the in-memory representation. A CharGroup is what can |
| * be seen as a traditional "trie node", except it can hold several characters at the |
| * same time. A CharGroup essentially represents one or several characters in the middle |
| * of the trie trie; as such, it can be a terminal, and it can have children. |
| * In this in-memory representation, whether the CharGroup is a terminal or not is represented |
| * in the frequency, where NOT_A_TERMINAL (= -1) means this is not a terminal and any other |
| * value is the frequency of this terminal. A terminal may have non-null shortcuts and/or |
| * bigrams, but a non-terminal may not. Moreover, children, if present, are null. |
| */ |
| public static final class CharGroup { |
| public static final int NOT_A_TERMINAL = -1; |
| final int mChars[]; |
| ArrayList<WeightedString> mShortcutTargets; |
| ArrayList<WeightedString> mBigrams; |
| int mFrequency; // NOT_A_TERMINAL == mFrequency indicates this is not a terminal. |
| Node mChildren; |
| boolean mIsNotAWord; // Only a shortcut |
| boolean mIsBlacklistEntry; |
| // The two following members to help with binary generation |
| int mCachedSize; |
| int mCachedAddress; |
| |
| public CharGroup(final int[] chars, final ArrayList<WeightedString> shortcutTargets, |
| final ArrayList<WeightedString> bigrams, final int frequency, |
| final boolean isNotAWord, final boolean isBlacklistEntry) { |
| mChars = chars; |
| mFrequency = frequency; |
| mShortcutTargets = shortcutTargets; |
| mBigrams = bigrams; |
| mChildren = null; |
| mIsNotAWord = isNotAWord; |
| mIsBlacklistEntry = isBlacklistEntry; |
| } |
| |
| public CharGroup(final int[] chars, final ArrayList<WeightedString> shortcutTargets, |
| final ArrayList<WeightedString> bigrams, final int frequency, |
| final boolean isNotAWord, final boolean isBlacklistEntry, final Node children) { |
| mChars = chars; |
| mFrequency = frequency; |
| mShortcutTargets = shortcutTargets; |
| mBigrams = bigrams; |
| mChildren = children; |
| mIsNotAWord = isNotAWord; |
| mIsBlacklistEntry = isBlacklistEntry; |
| } |
| |
| public void addChild(CharGroup n) { |
| if (null == mChildren) { |
| mChildren = new Node(); |
| } |
| mChildren.mData.add(n); |
| } |
| |
| public boolean isTerminal() { |
| return NOT_A_TERMINAL != mFrequency; |
| } |
| |
| public int getFrequency() { |
| return mFrequency; |
| } |
| |
| public boolean getIsNotAWord() { |
| return mIsNotAWord; |
| } |
| |
| public boolean getIsBlacklistEntry() { |
| return mIsBlacklistEntry; |
| } |
| |
| public ArrayList<WeightedString> getShortcutTargets() { |
| // We don't want write permission to escape outside the package, so we return a copy |
| if (null == mShortcutTargets) return null; |
| final ArrayList<WeightedString> copyOfShortcutTargets = |
| new ArrayList<WeightedString>(mShortcutTargets); |
| return copyOfShortcutTargets; |
| } |
| |
| public ArrayList<WeightedString> getBigrams() { |
| // We don't want write permission to escape outside the package, so we return a copy |
| if (null == mBigrams) return null; |
| final ArrayList<WeightedString> copyOfBigrams = new ArrayList<WeightedString>(mBigrams); |
| return copyOfBigrams; |
| } |
| |
| public boolean hasSeveralChars() { |
| assert(mChars.length > 0); |
| return 1 < mChars.length; |
| } |
| |
| /** |
| * Adds a word to the bigram list. Updates the frequency if the word already |
| * exists. |
| */ |
| public void addBigram(final String word, final int frequency) { |
| if (mBigrams == null) { |
| mBigrams = new ArrayList<WeightedString>(); |
| } |
| WeightedString bigram = getBigram(word); |
| if (bigram != null) { |
| bigram.mFrequency = frequency; |
| } else { |
| bigram = new WeightedString(word, frequency); |
| mBigrams.add(bigram); |
| } |
| } |
| |
| /** |
| * Gets the shortcut target for the given word. Returns null if the word is not in the |
| * shortcut list. |
| */ |
| public WeightedString getShortcut(final String word) { |
| // TODO: Don't do a linear search |
| if (mShortcutTargets != null) { |
| final int size = mShortcutTargets.size(); |
| for (int i = 0; i < size; ++i) { |
| WeightedString shortcut = mShortcutTargets.get(i); |
| if (shortcut.mWord.equals(word)) { |
| return shortcut; |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Gets the bigram for the given word. |
| * Returns null if the word is not in the bigrams list. |
| */ |
| public WeightedString getBigram(final String word) { |
| // TODO: Don't do a linear search |
| if (mBigrams != null) { |
| final int size = mBigrams.size(); |
| for (int i = 0; i < size; ++i) { |
| WeightedString bigram = mBigrams.get(i); |
| if (bigram.mWord.equals(word)) { |
| return bigram; |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Updates the CharGroup with the given properties. Adds the shortcut and bigram lists to |
| * the existing ones if any. Note: unigram, bigram, and shortcut frequencies are only |
| * updated if they are higher than the existing ones. |
| */ |
| public void update(final int frequency, final ArrayList<WeightedString> shortcutTargets, |
| final ArrayList<WeightedString> bigrams, |
| final boolean isNotAWord, final boolean isBlacklistEntry) { |
| if (frequency > mFrequency) { |
| mFrequency = frequency; |
| } |
| if (shortcutTargets != null) { |
| if (mShortcutTargets == null) { |
| mShortcutTargets = shortcutTargets; |
| } else { |
| final int size = shortcutTargets.size(); |
| for (int i = 0; i < size; ++i) { |
| final WeightedString shortcut = shortcutTargets.get(i); |
| final WeightedString existingShortcut = getShortcut(shortcut.mWord); |
| if (existingShortcut == null) { |
| mShortcutTargets.add(shortcut); |
| } else if (existingShortcut.mFrequency < shortcut.mFrequency) { |
| existingShortcut.mFrequency = shortcut.mFrequency; |
| } |
| } |
| } |
| } |
| if (bigrams != null) { |
| if (mBigrams == null) { |
| mBigrams = bigrams; |
| } else { |
| final int size = bigrams.size(); |
| for (int i = 0; i < size; ++i) { |
| final WeightedString bigram = bigrams.get(i); |
| final WeightedString existingBigram = getBigram(bigram.mWord); |
| if (existingBigram == null) { |
| mBigrams.add(bigram); |
| } else if (existingBigram.mFrequency < bigram.mFrequency) { |
| existingBigram.mFrequency = bigram.mFrequency; |
| } |
| } |
| } |
| } |
| mIsNotAWord = isNotAWord; |
| mIsBlacklistEntry = isBlacklistEntry; |
| } |
| } |
| |
| /** |
| * Options global to the dictionary. |
| */ |
| public static final class DictionaryOptions { |
| public final boolean mGermanUmlautProcessing; |
| public final boolean mFrenchLigatureProcessing; |
| public final HashMap<String, String> mAttributes; |
| public DictionaryOptions(final HashMap<String, String> attributes, |
| final boolean germanUmlautProcessing, final boolean frenchLigatureProcessing) { |
| mAttributes = attributes; |
| mGermanUmlautProcessing = germanUmlautProcessing; |
| mFrenchLigatureProcessing = frenchLigatureProcessing; |
| } |
| @Override |
| public String toString() { // Convenience method |
| return toString(0, false); |
| } |
| public String toString(final int indentCount, final boolean plumbing) { |
| final StringBuilder indent = new StringBuilder(); |
| if (plumbing) { |
| indent.append("H:"); |
| } else { |
| for (int i = 0; i < indentCount; ++i) { |
| indent.append(" "); |
| } |
| } |
| final StringBuilder s = new StringBuilder(); |
| for (final String optionKey : mAttributes.keySet()) { |
| s.append(indent); |
| s.append(optionKey); |
| s.append(" = "); |
| if ("date".equals(optionKey) && !plumbing) { |
| // Date needs a number of milliseconds, but the dictionary contains seconds |
| s.append(new Date( |
| 1000 * Long.parseLong(mAttributes.get(optionKey))).toString()); |
| } else { |
| s.append(mAttributes.get(optionKey)); |
| } |
| s.append("\n"); |
| } |
| if (mGermanUmlautProcessing) { |
| s.append(indent); |
| s.append("Needs German umlaut processing\n"); |
| } |
| if (mFrenchLigatureProcessing) { |
| s.append(indent); |
| s.append("Needs French ligature processing\n"); |
| } |
| return s.toString(); |
| } |
| } |
| |
| public final DictionaryOptions mOptions; |
| public final Node mRoot; |
| |
| public FusionDictionary(final Node root, final DictionaryOptions options) { |
| mRoot = root; |
| mOptions = options; |
| } |
| |
| public void addOptionAttribute(final String key, final String value) { |
| mOptions.mAttributes.put(key, value); |
| } |
| |
| /** |
| * Helper method to convert a String to an int array. |
| */ |
| static int[] getCodePoints(final String word) { |
| // TODO: this is a copy-paste of the contents of StringUtils.toCodePointArray, |
| // which is not visible from the makedict package. Factor this code. |
| final char[] characters = word.toCharArray(); |
| final int length = characters.length; |
| final int[] codePoints = new int[Character.codePointCount(characters, 0, length)]; |
| int codePoint = Character.codePointAt(characters, 0); |
| int dsti = 0; |
| for (int srci = Character.charCount(codePoint); |
| srci < length; srci += Character.charCount(codePoint), ++dsti) { |
| codePoints[dsti] = codePoint; |
| codePoint = Character.codePointAt(characters, srci); |
| } |
| codePoints[dsti] = codePoint; |
| return codePoints; |
| } |
| |
| /** |
| * Helper method to add a word as a string. |
| * |
| * This method adds a word to the dictionary with the given frequency. Optional |
| * lists of bigrams and shortcuts can be passed here. For each word inside, |
| * they will be added to the dictionary as necessary. |
| * |
| * @param word the word to add. |
| * @param frequency the frequency of the word, in the range [0..255]. |
| * @param shortcutTargets a list of shortcut targets for this word, or null. |
| * @param isNotAWord true if this should not be considered a word (e.g. shortcut only) |
| */ |
| public void add(final String word, final int frequency, |
| final ArrayList<WeightedString> shortcutTargets, final boolean isNotAWord) { |
| add(getCodePoints(word), frequency, shortcutTargets, isNotAWord, |
| false /* isBlacklistEntry */); |
| } |
| |
| /** |
| * Helper method to add a blacklist entry as a string. |
| * |
| * @param word the word to add as a blacklist entry. |
| * @param shortcutTargets a list of shortcut targets for this word, or null. |
| * @param isNotAWord true if this is not a word for spellcheking purposes (shortcut only or so) |
| */ |
| public void addBlacklistEntry(final String word, |
| final ArrayList<WeightedString> shortcutTargets, final boolean isNotAWord) { |
| add(getCodePoints(word), 0, shortcutTargets, isNotAWord, true /* isBlacklistEntry */); |
| } |
| |
| /** |
| * Sanity check for a node. |
| * |
| * This method checks that all CharGroups in a node are ordered as expected. |
| * If they are, nothing happens. If they aren't, an exception is thrown. |
| */ |
| private void checkStack(Node node) { |
| ArrayList<CharGroup> stack = node.mData; |
| int lastValue = -1; |
| for (int i = 0; i < stack.size(); ++i) { |
| int currentValue = stack.get(i).mChars[0]; |
| if (currentValue <= lastValue) |
| throw new RuntimeException("Invalid stack"); |
| else |
| lastValue = currentValue; |
| } |
| } |
| |
| /** |
| * Helper method to add a new bigram to the dictionary. |
| * |
| * @param word1 the previous word of the context |
| * @param word2 the next word of the context |
| * @param frequency the bigram frequency |
| */ |
| public void setBigram(final String word1, final String word2, final int frequency) { |
| CharGroup charGroup = findWordInTree(mRoot, word1); |
| if (charGroup != null) { |
| final CharGroup charGroup2 = findWordInTree(mRoot, word2); |
| if (charGroup2 == null) { |
| add(getCodePoints(word2), 0, null, false /* isNotAWord */, |
| false /* isBlacklistEntry */); |
| // The chargroup for the first word may have moved by the above insertion, |
| // if word1 and word2 share a common stem that happens not to have been |
| // a cutting point until now. In this case, we need to refresh charGroup. |
| charGroup = findWordInTree(mRoot, word1); |
| } |
| charGroup.addBigram(word2, frequency); |
| } else { |
| throw new RuntimeException("First word of bigram not found"); |
| } |
| } |
| |
| /** |
| * Add a word to this dictionary. |
| * |
| * The shortcuts, if any, have to be in the dictionary already. If they aren't, |
| * an exception is thrown. |
| * |
| * @param word the word, as an int array. |
| * @param frequency the frequency of the word, in the range [0..255]. |
| * @param shortcutTargets an optional list of shortcut targets for this word (null if none). |
| * @param isNotAWord true if this is not a word for spellcheking purposes (shortcut only or so) |
| * @param isBlacklistEntry true if this is a blacklisted word, false otherwise |
| */ |
| private void add(final int[] word, final int frequency, |
| final ArrayList<WeightedString> shortcutTargets, |
| final boolean isNotAWord, final boolean isBlacklistEntry) { |
| assert(frequency >= 0 && frequency <= 255); |
| if (word.length >= Constants.Dictionary.MAX_WORD_LENGTH) { |
| MakedictLog.w("Ignoring a word that is too long: word.length = " + word.length); |
| return; |
| } |
| |
| Node currentNode = mRoot; |
| int charIndex = 0; |
| |
| CharGroup currentGroup = null; |
| int differentCharIndex = 0; // Set by the loop to the index of the char that differs |
| int nodeIndex = findIndexOfChar(mRoot, word[charIndex]); |
| while (CHARACTER_NOT_FOUND != nodeIndex) { |
| currentGroup = currentNode.mData.get(nodeIndex); |
| differentCharIndex = compareArrays(currentGroup.mChars, word, charIndex); |
| if (ARRAYS_ARE_EQUAL != differentCharIndex |
| && differentCharIndex < currentGroup.mChars.length) break; |
| if (null == currentGroup.mChildren) break; |
| charIndex += currentGroup.mChars.length; |
| if (charIndex >= word.length) break; |
| currentNode = currentGroup.mChildren; |
| nodeIndex = findIndexOfChar(currentNode, word[charIndex]); |
| } |
| |
| if (-1 == nodeIndex) { |
| // No node at this point to accept the word. Create one. |
| final int insertionIndex = findInsertionIndex(currentNode, word[charIndex]); |
| final CharGroup newGroup = new CharGroup( |
| Arrays.copyOfRange(word, charIndex, word.length), |
| shortcutTargets, null /* bigrams */, frequency, isNotAWord, isBlacklistEntry); |
| currentNode.mData.add(insertionIndex, newGroup); |
| if (DBG) checkStack(currentNode); |
| } else { |
| // There is a word with a common prefix. |
| if (differentCharIndex == currentGroup.mChars.length) { |
| if (charIndex + differentCharIndex >= word.length) { |
| // The new word is a prefix of an existing word, but the node on which it |
| // should end already exists as is. Since the old CharNode was not a terminal, |
| // make it one by filling in its frequency and other attributes |
| currentGroup.update(frequency, shortcutTargets, null, isNotAWord, |
| isBlacklistEntry); |
| } else { |
| // The new word matches the full old word and extends past it. |
| // We only have to create a new node and add it to the end of this. |
| final CharGroup newNode = new CharGroup( |
| Arrays.copyOfRange(word, charIndex + differentCharIndex, word.length), |
| shortcutTargets, null /* bigrams */, frequency, isNotAWord, |
| isBlacklistEntry); |
| currentGroup.mChildren = new Node(); |
| currentGroup.mChildren.mData.add(newNode); |
| } |
| } else { |
| if (0 == differentCharIndex) { |
| // Exact same word. Update the frequency if higher. This will also add the |
| // new shortcuts to the existing shortcut list if it already exists. |
| currentGroup.update(frequency, shortcutTargets, null, |
| currentGroup.mIsNotAWord && isNotAWord, |
| currentGroup.mIsBlacklistEntry || isBlacklistEntry); |
| } else { |
| // Partial prefix match only. We have to replace the current node with a node |
| // containing the current prefix and create two new ones for the tails. |
| Node newChildren = new Node(); |
| final CharGroup newOldWord = new CharGroup( |
| Arrays.copyOfRange(currentGroup.mChars, differentCharIndex, |
| currentGroup.mChars.length), currentGroup.mShortcutTargets, |
| currentGroup.mBigrams, currentGroup.mFrequency, |
| currentGroup.mIsNotAWord, currentGroup.mIsBlacklistEntry, |
| currentGroup.mChildren); |
| newChildren.mData.add(newOldWord); |
| |
| final CharGroup newParent; |
| if (charIndex + differentCharIndex >= word.length) { |
| newParent = new CharGroup( |
| Arrays.copyOfRange(currentGroup.mChars, 0, differentCharIndex), |
| shortcutTargets, null /* bigrams */, frequency, |
| isNotAWord, isBlacklistEntry, newChildren); |
| } else { |
| newParent = new CharGroup( |
| Arrays.copyOfRange(currentGroup.mChars, 0, differentCharIndex), |
| null /* shortcutTargets */, null /* bigrams */, -1, |
| false /* isNotAWord */, false /* isBlacklistEntry */, newChildren); |
| final CharGroup newWord = new CharGroup(Arrays.copyOfRange(word, |
| charIndex + differentCharIndex, word.length), |
| shortcutTargets, null /* bigrams */, frequency, |
| isNotAWord, isBlacklistEntry); |
| final int addIndex = word[charIndex + differentCharIndex] |
| > currentGroup.mChars[differentCharIndex] ? 1 : 0; |
| newChildren.mData.add(addIndex, newWord); |
| } |
| currentNode.mData.set(nodeIndex, newParent); |
| } |
| if (DBG) checkStack(currentNode); |
| } |
| } |
| } |
| |
| private static int ARRAYS_ARE_EQUAL = 0; |
| |
| /** |
| * Custom comparison of two int arrays taken to contain character codes. |
| * |
| * This method compares the two arrays passed as an argument in a lexicographic way, |
| * with an offset in the dst string. |
| * This method does NOT test for the first character. It is taken to be equal. |
| * I repeat: this method starts the comparison at 1 <> dstOffset + 1. |
| * The index where the strings differ is returned. ARRAYS_ARE_EQUAL = 0 is returned if the |
| * strings are equal. This works BECAUSE we don't look at the first character. |
| * |
| * @param src the left-hand side string of the comparison. |
| * @param dst the right-hand side string of the comparison. |
| * @param dstOffset the offset in the right-hand side string. |
| * @return the index at which the strings differ, or ARRAYS_ARE_EQUAL = 0 if they don't. |
| */ |
| private static int compareArrays(final int[] src, final int[] dst, int dstOffset) { |
| // We do NOT test the first char, because we come from a method that already |
| // tested it. |
| for (int i = 1; i < src.length; ++i) { |
| if (dstOffset + i >= dst.length) return i; |
| if (src[i] != dst[dstOffset + i]) return i; |
| } |
| if (dst.length > src.length) return src.length; |
| return ARRAYS_ARE_EQUAL; |
| } |
| |
| /** |
| * Helper class that compares and sorts two chargroups according to their |
| * first element only. I repeat: ONLY the first element is considered, the rest |
| * is ignored. |
| * This comparator imposes orderings that are inconsistent with equals. |
| */ |
| static private final class CharGroupComparator implements java.util.Comparator<CharGroup> { |
| @Override |
| public int compare(CharGroup c1, CharGroup c2) { |
| if (c1.mChars[0] == c2.mChars[0]) return 0; |
| return c1.mChars[0] < c2.mChars[0] ? -1 : 1; |
| } |
| } |
| final static private CharGroupComparator CHARGROUP_COMPARATOR = new CharGroupComparator(); |
| |
| /** |
| * Finds the insertion index of a character within a node. |
| */ |
| private static int findInsertionIndex(final Node node, int character) { |
| final ArrayList<CharGroup> data = node.mData; |
| final CharGroup reference = new CharGroup(new int[] { character }, |
| null /* shortcutTargets */, null /* bigrams */, 0, false /* isNotAWord */, |
| false /* isBlacklistEntry */); |
| int result = Collections.binarySearch(data, reference, CHARGROUP_COMPARATOR); |
| return result >= 0 ? result : -result - 1; |
| } |
| |
| private static int CHARACTER_NOT_FOUND = -1; |
| |
| /** |
| * Find the index of a char in a node, if it exists. |
| * |
| * @param node the node to search in. |
| * @param character the character to search for. |
| * @return the position of the character if it's there, or CHARACTER_NOT_FOUND = -1 else. |
| */ |
| private static int findIndexOfChar(final Node node, int character) { |
| final int insertionIndex = findInsertionIndex(node, character); |
| if (node.mData.size() <= insertionIndex) return CHARACTER_NOT_FOUND; |
| return character == node.mData.get(insertionIndex).mChars[0] ? insertionIndex |
| : CHARACTER_NOT_FOUND; |
| } |
| |
| /** |
| * Helper method to find a word in a given branch. |
| */ |
| @SuppressWarnings("unused") |
| public static CharGroup findWordInTree(Node node, final String string) { |
| int index = 0; |
| final StringBuilder checker = DBG ? new StringBuilder() : null; |
| final int[] codePoints = getCodePoints(string); |
| |
| CharGroup currentGroup; |
| do { |
| int indexOfGroup = findIndexOfChar(node, codePoints[index]); |
| if (CHARACTER_NOT_FOUND == indexOfGroup) return null; |
| currentGroup = node.mData.get(indexOfGroup); |
| |
| if (codePoints.length - index < currentGroup.mChars.length) return null; |
| int newIndex = index; |
| while (newIndex < codePoints.length && newIndex - index < currentGroup.mChars.length) { |
| if (currentGroup.mChars[newIndex - index] != codePoints[newIndex]) return null; |
| newIndex++; |
| } |
| index = newIndex; |
| |
| if (DBG) checker.append(new String(currentGroup.mChars, 0, currentGroup.mChars.length)); |
| if (index < codePoints.length) { |
| node = currentGroup.mChildren; |
| } |
| } while (null != node && index < codePoints.length); |
| |
| if (index < codePoints.length) return null; |
| if (!currentGroup.isTerminal()) return null; |
| if (DBG && !string.equals(checker.toString())) return null; |
| return currentGroup; |
| } |
| |
| /** |
| * Helper method to find out whether a word is in the dict or not. |
| */ |
| public boolean hasWord(final String s) { |
| if (null == s || "".equals(s)) { |
| throw new RuntimeException("Can't search for a null or empty string"); |
| } |
| return null != findWordInTree(mRoot, s); |
| } |
| |
| /** |
| * Recursively count the number of character groups in a given branch of the trie. |
| * |
| * @param node the parent node. |
| * @return the number of char groups in all the branch under this node. |
| */ |
| public static int countCharGroups(final Node node) { |
| final int nodeSize = node.mData.size(); |
| int size = nodeSize; |
| for (int i = nodeSize - 1; i >= 0; --i) { |
| CharGroup group = node.mData.get(i); |
| if (null != group.mChildren) |
| size += countCharGroups(group.mChildren); |
| } |
| return size; |
| } |
| |
| /** |
| * Recursively count the number of nodes in a given branch of the trie. |
| * |
| * @param node the node to count. |
| * @return the number of nodes in this branch. |
| */ |
| public static int countNodes(final Node node) { |
| int size = 1; |
| for (int i = node.mData.size() - 1; i >= 0; --i) { |
| CharGroup group = node.mData.get(i); |
| if (null != group.mChildren) |
| size += countNodes(group.mChildren); |
| } |
| return size; |
| } |
| |
| // Recursively find out whether there are any bigrams. |
| // This can be pretty expensive especially if there aren't any (we return as soon |
| // as we find one, so it's much cheaper if there are bigrams) |
| private static boolean hasBigramsInternal(final Node node) { |
| if (null == node) return false; |
| for (int i = node.mData.size() - 1; i >= 0; --i) { |
| CharGroup group = node.mData.get(i); |
| if (null != group.mBigrams) return true; |
| if (hasBigramsInternal(group.mChildren)) return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Finds out whether there are any bigrams in this dictionary. |
| * |
| * @return true if there is any bigram, false otherwise. |
| */ |
| // TODO: this is expensive especially for large dictionaries without any bigram. |
| // The up side is, this is always accurate and correct and uses no memory. We should |
| // find a more efficient way of doing this, without compromising too much on memory |
| // and ease of use. |
| public boolean hasBigrams() { |
| return hasBigramsInternal(mRoot); |
| } |
| |
| // Historically, the tails of the words were going to be merged to save space. |
| // However, that would prevent the code to search for a specific address in log(n) |
| // time so this was abandoned. |
| // The code is still of interest as it does add some compression to any dictionary |
| // that has no need for attributes. Implementations that does not read attributes should be |
| // able to read a dictionary with merged tails. |
| // Also, the following code does support frequencies, as in, it will only merges |
| // tails that share the same frequency. Though it would result in the above loss of |
| // performance while searching by address, it is still technically possible to merge |
| // tails that contain attributes, but this code does not take that into account - it does |
| // not compare attributes and will merge terminals with different attributes regardless. |
| public void mergeTails() { |
| MakedictLog.i("Do not merge tails"); |
| return; |
| |
| // MakedictLog.i("Merging nodes. Number of nodes : " + countNodes(root)); |
| // MakedictLog.i("Number of groups : " + countCharGroups(root)); |
| // |
| // final HashMap<String, ArrayList<Node>> repository = |
| // new HashMap<String, ArrayList<Node>>(); |
| // mergeTailsInner(repository, root); |
| // |
| // MakedictLog.i("Number of different pseudohashes : " + repository.size()); |
| // int size = 0; |
| // for (ArrayList<Node> a : repository.values()) { |
| // size += a.size(); |
| // } |
| // MakedictLog.i("Number of nodes after merge : " + (1 + size)); |
| // MakedictLog.i("Recursively seen nodes : " + countNodes(root)); |
| } |
| |
| // The following methods are used by the deactivated mergeTails() |
| // private static boolean isEqual(Node a, Node b) { |
| // if (null == a && null == b) return true; |
| // if (null == a || null == b) return false; |
| // if (a.data.size() != b.data.size()) return false; |
| // final int size = a.data.size(); |
| // for (int i = size - 1; i >= 0; --i) { |
| // CharGroup aGroup = a.data.get(i); |
| // CharGroup bGroup = b.data.get(i); |
| // if (aGroup.frequency != bGroup.frequency) return false; |
| // if (aGroup.alternates == null && bGroup.alternates != null) return false; |
| // if (aGroup.alternates != null && !aGroup.equals(bGroup.alternates)) return false; |
| // if (!Arrays.equals(aGroup.chars, bGroup.chars)) return false; |
| // if (!isEqual(aGroup.children, bGroup.children)) return false; |
| // } |
| // return true; |
| // } |
| |
| // static private HashMap<String, ArrayList<Node>> mergeTailsInner( |
| // final HashMap<String, ArrayList<Node>> map, final Node node) { |
| // final ArrayList<CharGroup> branches = node.data; |
| // final int nodeSize = branches.size(); |
| // for (int i = 0; i < nodeSize; ++i) { |
| // CharGroup group = branches.get(i); |
| // if (null != group.children) { |
| // String pseudoHash = getPseudoHash(group.children); |
| // ArrayList<Node> similarList = map.get(pseudoHash); |
| // if (null == similarList) { |
| // similarList = new ArrayList<Node>(); |
| // map.put(pseudoHash, similarList); |
| // } |
| // boolean merged = false; |
| // for (Node similar : similarList) { |
| // if (isEqual(group.children, similar)) { |
| // group.children = similar; |
| // merged = true; |
| // break; |
| // } |
| // } |
| // if (!merged) { |
| // similarList.add(group.children); |
| // } |
| // mergeTailsInner(map, group.children); |
| // } |
| // } |
| // return map; |
| // } |
| |
| // private static String getPseudoHash(final Node node) { |
| // StringBuilder s = new StringBuilder(); |
| // for (CharGroup g : node.data) { |
| // s.append(g.frequency); |
| // for (int ch : g.chars) { |
| // s.append(Character.toChars(ch)); |
| // } |
| // } |
| // return s.toString(); |
| // } |
| |
| /** |
| * Iterator to walk through a dictionary. |
| * |
| * This is purely for convenience. |
| */ |
| public static final class DictionaryIterator implements Iterator<Word> { |
| private static final class Position { |
| public Iterator<CharGroup> pos; |
| public int length; |
| public Position(ArrayList<CharGroup> groups) { |
| pos = groups.iterator(); |
| length = 0; |
| } |
| } |
| final StringBuilder mCurrentString; |
| final LinkedList<Position> mPositions; |
| |
| public DictionaryIterator(ArrayList<CharGroup> root) { |
| mCurrentString = new StringBuilder(); |
| mPositions = new LinkedList<Position>(); |
| final Position rootPos = new Position(root); |
| mPositions.add(rootPos); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| for (Position p : mPositions) { |
| if (p.pos.hasNext()) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| @Override |
| public Word next() { |
| Position currentPos = mPositions.getLast(); |
| mCurrentString.setLength(currentPos.length); |
| |
| do { |
| if (currentPos.pos.hasNext()) { |
| final CharGroup currentGroup = currentPos.pos.next(); |
| currentPos.length = mCurrentString.length(); |
| for (int i : currentGroup.mChars) { |
| mCurrentString.append(Character.toChars(i)); |
| } |
| if (null != currentGroup.mChildren) { |
| currentPos = new Position(currentGroup.mChildren.mData); |
| currentPos.length = mCurrentString.length(); |
| mPositions.addLast(currentPos); |
| } |
| if (currentGroup.mFrequency >= 0) { |
| return new Word(mCurrentString.toString(), currentGroup.mFrequency, |
| currentGroup.mShortcutTargets, currentGroup.mBigrams, |
| currentGroup.mIsNotAWord, currentGroup.mIsBlacklistEntry); |
| } |
| } else { |
| mPositions.removeLast(); |
| currentPos = mPositions.getLast(); |
| mCurrentString.setLength(mPositions.getLast().length); |
| } |
| } while (true); |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException("Unsupported yet"); |
| } |
| |
| } |
| |
| /** |
| * Method to return an iterator. |
| * |
| * This method enables Java's enhanced for loop. With this you can have a FusionDictionary x |
| * and say : for (Word w : x) {} |
| */ |
| @Override |
| public Iterator<Word> iterator() { |
| return new DictionaryIterator(mRoot.mData); |
| } |
| } |
