LatinIME/java/src/com/android/inputmethod/latin/PersonalDictionaryLookup.java

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/*
* Copyright (C) 2015 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;
import android.content.ContentResolver;
import android.content.Context;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.provider.UserDictionary;
import android.text.TextUtils;
import android.util.Log;
import com.android.inputmethod.annotations.UsedForTesting;
import com.android.inputmethod.latin.common.CollectionUtils;
import com.android.inputmethod.latin.common.LocaleUtils;
import com.android.inputmethod.latin.define.DebugFlags;
import com.android.inputmethod.latin.utils.ExecutorUtils;
import java.io.Closeable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
/**
* This class provides the ability to look into the system-wide "Personal dictionary". It loads the
* data once when created and reloads it when notified of changes to {@link UserDictionary}
*
* It can be used directly to validate words or expand shortcuts, and it can be used by instances
* of {@link PersonalLanguageModelHelper} that create language model files for a specific input
* locale.
*
* Note, that the initial dictionary loading happens asynchronously so it is possible (hopefully
* rarely) that {@link #isValidWord} or {@link #expandShortcut} is called before the initial load
* has started.
*
* The caller should explicitly call {@link #close} when the object is no longer needed, in order
* to release any resources and references to this object. A service should create this object in
* {@link android.app.Service#onCreate} and close it in {@link android.app.Service#onDestroy}.
*/
public class PersonalDictionaryLookup implements Closeable {
/**
* To avoid loading too many dictionary entries in memory, we cap them at this number. If
* that number is exceeded, the lowest-frequency items will be dropped. Note, there is no
* explicit cap on the number of locales in every entry.
*/
private static final int MAX_NUM_ENTRIES = 1000;
/**
* The delay (in milliseconds) to impose on reloads. Previously scheduled reloads will be
* cancelled if a new reload is scheduled before the delay expires. Thus, only the last
* reload in the series of frequent reloads will execute.
*
* Note, this value should be low enough to allow the "Add to dictionary" feature in the
* TextView correction (red underline) drop-down menu to work properly in the following case:
*
* 1. User types OOV (out-of-vocabulary) word.
* 2. The OOV is red-underlined.
* 3. User selects "Add to dictionary". The red underline disappears while the OOV is
* in a composing span.
* 4. The user taps space. The red underline should NOT reappear. If this value is very
* high and the user performs the space tap fast enough, the red underline may reappear.
*/
@UsedForTesting
static final int RELOAD_DELAY_MS = 200;
@UsedForTesting
static final Locale ANY_LOCALE = new Locale("");
private final String mTag;
private final ContentResolver mResolver;
private final String mServiceName;
/**
* Interface to implement for classes interested in getting notified of updates.
*/
public static interface PersonalDictionaryListener {
public void onUpdate();
}
private final Set<PersonalDictionaryListener> mListeners = new HashSet<>();
public void addListener(@Nonnull final PersonalDictionaryListener listener) {
mListeners.add(listener);
}
public void removeListener(@Nonnull final PersonalDictionaryListener listener) {
mListeners.remove(listener);
}
/**
* Broadcast the update to all the Locale-specific language models.
*/
@UsedForTesting
void notifyListeners() {
for (PersonalDictionaryListener listener : mListeners) {
listener.onUpdate();
}
}
/**
* Content observer for changes to the personal dictionary. It has the following properties:
* 1. It spawns off a reload in another thread, after some delay.
* 2. It cancels previously scheduled reloads, and only executes the latest.
* 3. It may be called multiple times quickly in succession (and is in fact called so
* when the dictionary is edited through its settings UI, when sometimes multiple
* notifications are sent for the edited entry, but also for the entire dictionary).
*/
private class PersonalDictionaryContentObserver extends ContentObserver implements Runnable {
public PersonalDictionaryContentObserver() {
super(null);
}
@Override
public boolean deliverSelfNotifications() {
return true;
}
// Support pre-API16 platforms.
@Override
public void onChange(boolean selfChange) {
onChange(selfChange, null);
}
@Override
public void onChange(boolean selfChange, Uri uri) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "onChange() : URI = " + uri);
}
// Cancel (but don't interrupt) any pending reloads (except the initial load).
if (mReloadFuture != null && !mReloadFuture.isCancelled() &&
!mReloadFuture.isDone()) {
// Note, that if already cancelled or done, this will do nothing.
boolean isCancelled = mReloadFuture.cancel(false);
if (DebugFlags.DEBUG_ENABLED) {
if (isCancelled) {
Log.d(mTag, "onChange() : Canceled previous reload request");
} else {
Log.d(mTag, "onChange() : Failed to cancel previous reload request");
}
}
}
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "onChange() : Scheduling reload in " + RELOAD_DELAY_MS + " ms");
}
// Schedule a new reload after RELOAD_DELAY_MS.
mReloadFuture = ExecutorUtils.getBackgroundExecutor(mServiceName)
.schedule(this, RELOAD_DELAY_MS, TimeUnit.MILLISECONDS);
}
@Override
public void run() {
loadPersonalDictionary();
}
}
private final PersonalDictionaryContentObserver mPersonalDictionaryContentObserver =
new PersonalDictionaryContentObserver();
/**
* Indicates that a load is in progress, so no need for another.
*/
private AtomicBoolean mIsLoading = new AtomicBoolean(false);
/**
* Indicates that this lookup object has been close()d.
*/
private AtomicBoolean mIsClosed = new AtomicBoolean(false);
/**
* We store a map from a dictionary word to the set of locales & raw string(as it appears)
* We then iterate over the set of locales to find a match using LocaleUtils.
*/
private volatile HashMap<String, HashMap<Locale, String>> mDictWords;
/**
* We store a map from a shortcut to a word for each locale.
* Shortcuts that apply to any locale are keyed by {@link #ANY_LOCALE}.
*/
private volatile HashMap<Locale, HashMap<String, String>> mShortcutsPerLocale;
/**
* The last-scheduled reload future. Saved in order to cancel a pending reload if a new one
* is coming.
*/
private volatile ScheduledFuture<?> mReloadFuture;
private volatile List<DictionaryStats> mDictionaryStats;
/**
* @param context the context from which to obtain content resolver
*/
public PersonalDictionaryLookup(
@Nonnull final Context context,
@Nonnull final String serviceName) {
mTag = serviceName + ".Personal";
Log.i(mTag, "create()");
mServiceName = serviceName;
mDictionaryStats = new ArrayList<DictionaryStats>();
mDictionaryStats.add(new DictionaryStats(ANY_LOCALE, Dictionary.TYPE_USER, 0));
mDictionaryStats.add(new DictionaryStats(ANY_LOCALE, Dictionary.TYPE_USER_SHORTCUT, 0));
// Obtain a content resolver.
mResolver = context.getContentResolver();
}
public List<DictionaryStats> getDictionaryStats() {
return mDictionaryStats;
}
public void open() {
Log.i(mTag, "open()");
// Schedule the initial load to run immediately. It's possible that the first call to
// isValidWord occurs before the dictionary has actually loaded, so it should not
// assume that the dictionary has been loaded.
loadPersonalDictionary();
// Register the observer to be notified on changes to the personal dictionary and all
// individual items.
//
// If the user is interacting with the Personal Dictionary settings UI, or with the
// "Add to dictionary" drop-down option, duplicate notifications will be sent for the same
// edit: if a new entry is added, there is a notification for the entry itself, and
// separately for the entire dictionary. However, when used programmatically,
// only notifications for the specific edits are sent. Thus, the observer is registered to
// receive every possible notification, and instead has throttling logic to avoid doing too
// many reloads.
mResolver.registerContentObserver(
UserDictionary.Words.CONTENT_URI,
true /* notifyForDescendents */,
mPersonalDictionaryContentObserver);
}
/**
* To be called by the garbage collector in the off chance that the service did not clean up
* properly. Do not rely on this getting called, and make sure close() is called explicitly.
*/
@Override
public void finalize() throws Throwable {
try {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "finalize()");
}
close();
} finally {
super.finalize();
}
}
/**
* Cleans up PersonalDictionaryLookup: shuts down any extra threads and unregisters the observer.
*
* It is safe, but not advised to call this multiple times, and isValidWord would continue to
* work, but no data will be reloaded any longer.
*/
@Override
public void close() {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "close() : Unregistering content observer");
}
if (mIsClosed.compareAndSet(false, true)) {
// Unregister the content observer.
mResolver.unregisterContentObserver(mPersonalDictionaryContentObserver);
}
}
/**
* Returns true if the initial load has been performed.
*
* @return true if the initial load is successful
*/
public boolean isLoaded() {
return mDictWords != null && mShortcutsPerLocale != null;
}
/**
* Returns the set of words defined for the given locale and more general locales.
*
* For example, input locale en_US uses data for en_US, en, and the global dictionary.
*
* Note that this method returns expanded words, not shortcuts. Shortcuts are handled
* by {@link #getShortcutsForLocale}.
*
* @param inputLocale the locale to restrict for
* @return set of words that apply to the given locale.
*/
public Set<String> getWordsForLocale(@Nonnull final Locale inputLocale) {
final HashMap<String, HashMap<Locale, String>> dictWords = mDictWords;
if (CollectionUtils.isNullOrEmpty(dictWords)) {
return Collections.emptySet();
}
final Set<String> words = new HashSet<>();
final String inputLocaleString = inputLocale.toString();
for (String word : dictWords.keySet()) {
HashMap<Locale, String> localeStringMap = dictWords.get(word);
if (!CollectionUtils.isNullOrEmpty(localeStringMap)) {
for (Locale wordLocale : localeStringMap.keySet()) {
final String wordLocaleString = wordLocale.toString();
final int match = LocaleUtils.getMatchLevel(wordLocaleString, inputLocaleString);
if (LocaleUtils.isMatch(match)) {
words.add(localeStringMap.get(wordLocale));
}
}
}
}
return words;
}
/**
* Returns the set of shortcuts defined for the given locale and more general locales.
*
* For example, input locale en_US uses data for en_US, en, and the global dictionary.
*
* Note that this method returns shortcut keys, not expanded words. Words are handled
* by {@link #getWordsForLocale}.
*
* @param inputLocale the locale to restrict for
* @return set of shortcuts that apply to the given locale.
*/
public Set<String> getShortcutsForLocale(@Nonnull final Locale inputLocale) {
final Map<Locale, HashMap<String, String>> shortcutsPerLocale = mShortcutsPerLocale;
if (CollectionUtils.isNullOrEmpty(shortcutsPerLocale)) {
return Collections.emptySet();
}
final Set<String> shortcuts = new HashSet<>();
if (!TextUtils.isEmpty(inputLocale.getCountry())) {
// First look for the country-specific shortcut: en_US, en_UK, fr_FR, etc.
final Map<String, String> countryShortcuts = shortcutsPerLocale.get(inputLocale);
if (!CollectionUtils.isNullOrEmpty(countryShortcuts)) {
shortcuts.addAll(countryShortcuts.keySet());
}
}
// Next look for the language-specific shortcut: en, fr, etc.
final Locale languageOnlyLocale =
LocaleUtils.constructLocaleFromString(inputLocale.getLanguage());
final Map<String, String> languageShortcuts = shortcutsPerLocale.get(languageOnlyLocale);
if (!CollectionUtils.isNullOrEmpty(languageShortcuts)) {
shortcuts.addAll(languageShortcuts.keySet());
}
// If all else fails, look for a global shortcut.
final Map<String, String> globalShortcuts = shortcutsPerLocale.get(ANY_LOCALE);
if (!CollectionUtils.isNullOrEmpty(globalShortcuts)) {
shortcuts.addAll(globalShortcuts.keySet());
}
return shortcuts;
}
/**
* Determines if the given word is a valid word in the given locale based on the dictionary.
* It tries hard to find a match: for example, casing is ignored and if the word is present in a
* more general locale (e.g. en or all locales), and isValidWord is asking for a more specific
* locale (e.g. en_US), it will be considered a match.
*
* @param word the word to match
* @param inputLocale the locale in which to match the word
* @return true iff the word has been matched for this locale in the dictionary.
*/
public boolean isValidWord(@Nonnull final String word, @Nonnull final Locale inputLocale) {
if (!isLoaded()) {
// This is a corner case in the event the initial load of the dictionary has not
// completed. In that case, we assume the word is not a valid word in the dictionary.
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : Initial load not complete");
}
return false;
}
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : Word [" + word + "] in Locale [" + inputLocale + "]");
}
// Atomically obtain the current copy of mDictWords;
final HashMap<String, HashMap<Locale, String>> dictWords = mDictWords;
// Lowercase the word using the given locale. Note, that dictionary
// words are lowercased using their locale, and theoretically the
// lowercasing between two matching locales may differ. For simplicity
// we ignore that possibility.
final String lowercased = word.toLowerCase(inputLocale);
final HashMap<Locale, String> dictLocales = dictWords.get(lowercased);
if (CollectionUtils.isNullOrEmpty(dictLocales)) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : No entry for word [" + word + "]");
}
return false;
} else {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : Found entry for word [" + word + "]");
}
// Iterate over the locales this word is in.
for (final Locale dictLocale : dictLocales.keySet()) {
final int matchLevel = LocaleUtils.getMatchLevel(dictLocale.toString(),
inputLocale.toString());
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : MatchLevel for DictLocale [" + dictLocale
+ "] and InputLocale [" + inputLocale + "] is " + matchLevel);
}
if (LocaleUtils.isMatch(matchLevel)) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : MatchLevel " + matchLevel + " IS a match");
}
return true;
}
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : MatchLevel " + matchLevel + " is NOT a match");
}
}
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "isValidWord() : False, since none of the locales matched");
}
return false;
}
}
/**
* Expands the given shortcut for the given locale.
*
* @param shortcut the shortcut to expand
* @param inputLocale the locale in which to expand the shortcut
* @return expanded shortcut iff the word is a shortcut in the dictionary.
*/
@Nullable public String expandShortcut(
@Nonnull final String shortcut, @Nonnull final Locale inputLocale) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "expandShortcut() : Shortcut [" + shortcut + "] for [" + inputLocale + "]");
}
// Atomically obtain the current copy of mShortcuts;
final HashMap<Locale, HashMap<String, String>> shortcutsPerLocale = mShortcutsPerLocale;
// Exit as early as possible. Most users don't use shortcuts.
if (CollectionUtils.isNullOrEmpty(shortcutsPerLocale)) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "expandShortcut() : User has no shortcuts");
}
return null;
}
if (!TextUtils.isEmpty(inputLocale.getCountry())) {
// First look for the country-specific shortcut: en_US, en_UK, fr_FR, etc.
final String expansionForCountry = expandShortcut(
shortcutsPerLocale, shortcut, inputLocale);
if (!TextUtils.isEmpty(expansionForCountry)) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "expandShortcut() : Country expansion is ["
+ expansionForCountry + "]");
}
return expansionForCountry;
}
}
// Next look for the language-specific shortcut: en, fr, etc.
final Locale languageOnlyLocale =
LocaleUtils.constructLocaleFromString(inputLocale.getLanguage());
final String expansionForLanguage = expandShortcut(
shortcutsPerLocale, shortcut, languageOnlyLocale);
if (!TextUtils.isEmpty(expansionForLanguage)) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "expandShortcut() : Language expansion is ["
+ expansionForLanguage + "]");
}
return expansionForLanguage;
}
// If all else fails, look for a global shortcut.
final String expansionForGlobal = expandShortcut(shortcutsPerLocale, shortcut, ANY_LOCALE);
if (!TextUtils.isEmpty(expansionForGlobal) && DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "expandShortcut() : Global expansion is [" + expansionForGlobal + "]");
}
return expansionForGlobal;
}
@Nullable private String expandShortcut(
@Nullable final HashMap<Locale, HashMap<String, String>> shortcutsPerLocale,
@Nonnull final String shortcut,
@Nonnull final Locale locale) {
if (CollectionUtils.isNullOrEmpty(shortcutsPerLocale)) {
return null;
}
final HashMap<String, String> localeShortcuts = shortcutsPerLocale.get(locale);
if (CollectionUtils.isNullOrEmpty(localeShortcuts)) {
return null;
}
return localeShortcuts.get(shortcut);
}
/**
* Loads the personal dictionary in the current thread.
*
* Only one reload can happen at a time. If already running, will exit quickly.
*/
private void loadPersonalDictionary() {
// Bail out if already in the process of loading.
if (!mIsLoading.compareAndSet(false, true)) {
Log.i(mTag, "loadPersonalDictionary() : Already Loading (exit)");
return;
}
Log.i(mTag, "loadPersonalDictionary() : Start Loading");
HashMap<String, HashMap<Locale, String>> dictWords = new HashMap<>();
HashMap<Locale, HashMap<String, String>> shortcutsPerLocale = new HashMap<>();
// Load the dictionary. Items are returned in the default sort order (by frequency).
Cursor cursor = mResolver.query(UserDictionary.Words.CONTENT_URI,
null, null, null, UserDictionary.Words.DEFAULT_SORT_ORDER);
if (null == cursor || cursor.getCount() < 1) {
Log.i(mTag, "loadPersonalDictionary() : Empty");
} else {
// Iterate over the entries in the personal dictionary. Note, that iteration is in
// descending frequency by default.
while (dictWords.size() < MAX_NUM_ENTRIES && cursor.moveToNext()) {
// If there is no column for locale, skip this entry. An empty
// locale on the other hand will not be skipped.
final int dictLocaleIndex = cursor.getColumnIndex(UserDictionary.Words.LOCALE);
if (dictLocaleIndex < 0) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Entry without LOCALE, skipping");
}
continue;
}
// If there is no column for word, skip this entry.
final int dictWordIndex = cursor.getColumnIndex(UserDictionary.Words.WORD);
if (dictWordIndex < 0) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Entry without WORD, skipping");
}
continue;
}
// If the word is null, skip this entry.
final String rawDictWord = cursor.getString(dictWordIndex);
if (null == rawDictWord) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Null word");
}
continue;
}
// If the locale is null, that's interpreted to mean all locales. Note, the special
// zz locale for an Alphabet (QWERTY) layout will not match any actual language.
String localeString = cursor.getString(dictLocaleIndex);
if (null == localeString) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Null locale for word [" +
rawDictWord + "], assuming all locales");
}
// For purposes of LocaleUtils, an empty locale matches everything.
localeString = "";
}
final Locale dictLocale = LocaleUtils.constructLocaleFromString(localeString);
// Lowercase the word before storing it.
final String dictWord = rawDictWord.toLowerCase(dictLocale);
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Adding word [" + dictWord
+ "] for locale " + dictLocale + "with value" + rawDictWord);
}
// Check if there is an existing entry for this word.
HashMap<Locale, String> dictLocales = dictWords.get(dictWord);
if (CollectionUtils.isNullOrEmpty(dictLocales)) {
// If there is no entry for this word, create one.
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Word [" + dictWord +
"] not seen for other locales, creating new entry");
}
dictLocales = new HashMap<>();
dictWords.put(dictWord, dictLocales);
}
// Append the locale to the list of locales this word is in.
dictLocales.put(dictLocale, rawDictWord);
// If there is no column for a shortcut, we're done.
final int shortcutIndex = cursor.getColumnIndex(UserDictionary.Words.SHORTCUT);
if (shortcutIndex < 0) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Entry without SHORTCUT, done");
}
continue;
}
// If the shortcut is null, we're done.
final String shortcut = cursor.getString(shortcutIndex);
if (shortcut == null) {
if (DebugFlags.DEBUG_ENABLED) {
Log.d(mTag, "loadPersonalDictionary() : Null shortcut");
}
continue;
}
// Else, save the shortcut.
HashMap<String, String> localeShortcuts = shortcutsPerLocale.get(dictLocale);
if (localeShortcuts == null) {
localeShortcuts = new HashMap<>();
shortcutsPerLocale.put(dictLocale, localeShortcuts);
}
// Map to the raw input, which might be capitalized.
// This lets the user create a shortcut from "gm" to "General Motors".
localeShortcuts.put(shortcut, rawDictWord);
}
}
List<DictionaryStats> stats = new ArrayList<>();
stats.add(new DictionaryStats(ANY_LOCALE, Dictionary.TYPE_USER, dictWords.size()));
int numShortcuts = 0;
for (HashMap<String, String> shortcuts : shortcutsPerLocale.values()) {
numShortcuts += shortcuts.size();
}
stats.add(new DictionaryStats(ANY_LOCALE, Dictionary.TYPE_USER_SHORTCUT, numShortcuts));
mDictionaryStats = stats;
// Atomically replace the copy of mDictWords and mShortcuts.
mDictWords = dictWords;
mShortcutsPerLocale = shortcutsPerLocale;
// Allow other calls to loadPersonalDictionary to execute now.
mIsLoading.set(false);
Log.i(mTag, "loadPersonalDictionary() : Loaded " + mDictWords.size()
+ " words and " + numShortcuts + " shortcuts");
notifyListeners();
}
}