am 5a8d2fd1: Merge "Cache UserHistoryDictionary for each language" into jb-dev

* commit '5a8d2fd1d353b2039f0d340301f9dac779cb4e64':
  Cache UserHistoryDictionary for each language

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

@@ -497,7 +497,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         // Note that the calling sequence of onCreate() and onCurrentInputMethodSubtypeChanged()
         // is not guaranteed. It may even be called at the same time on a different thread.
         if (null == mPrefs) mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
-        mUserHistoryDictionary = new UserHistoryDictionary(
+        mUserHistoryDictionary = UserHistoryDictionary.getInstance(
                 this, localeStr, Suggest.DIC_USER_HISTORY, mPrefs);
         mSuggest.setUserHistoryDictionary(mUserHistoryDictionary);
     }

java/src/com/android/inputmethod/latin/UserHistoryDictionary.java

@@ -29,7 +29,9 @@ import android.util.Log;
 
 import com.android.inputmethod.latin.UserHistoryForgettingCurveUtils.ForgettingCurveParams;
 
+import java.lang.ref.SoftReference;
 import java.util.HashMap;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Locally gathers stats about the words user types and various other signals like auto-correction
@@ -38,6 +40,7 @@ import java.util.HashMap;
 public class UserHistoryDictionary extends ExpandableDictionary {
     private static final String TAG = "UserHistoryDictionary";
     public static final boolean DBG_SAVE_RESTORE = false;
+    public static final boolean PROFILE_SAVE_RESTORE = LatinImeLogger.sDBG;
 
     /** Any pair being typed or picked */
     private static final int FREQUENCY_FOR_TYPED = 2;
@@ -77,13 +80,14 @@ public class UserHistoryDictionary extends ExpandableDictionary {
     /** Locale for which this user history dictionary is storing words */
     private final String mLocale;
 
-    private UserHistoryDictionaryBigramList mBigramList =
+    private final UserHistoryDictionaryBigramList mBigramList =
             new UserHistoryDictionaryBigramList();
-    private final Object mPendingWritesLock = new Object();
     private static volatile boolean sUpdatingDB = false;
     private final SharedPreferences mPrefs;
 
     private final static HashMap<String, String> sDictProjectionMap;
+    private final static ConcurrentHashMap<String, SoftReference<UserHistoryDictionary>>
+            sLangDictCache = new ConcurrentHashMap<String, SoftReference<UserHistoryDictionary>>();
 
     static {
         sDictProjectionMap = new HashMap<String, String>();
@@ -107,7 +111,26 @@ public class UserHistoryDictionary extends ExpandableDictionary {
         sDeleteHistoryBigrams = deleteHistoryBigram;
     }
 
-    public UserHistoryDictionary(final Context context, final String locale, final int dicTypeId,
+    public synchronized static UserHistoryDictionary getInstance(
+            final Context context, final String locale,
+            final int dictTypeId, final SharedPreferences sp) {
+        if (sLangDictCache.containsKey(locale)) {
+            final SoftReference<UserHistoryDictionary> ref = sLangDictCache.get(locale);
+            final UserHistoryDictionary dict = ref == null ? null : ref.get();
+            if (dict != null) {
+                if (PROFILE_SAVE_RESTORE) {
+                    Log.w(TAG, "Use cached UserHistoryDictionary for " + locale);
+                }
+                return dict;
+            }
+        }
+        final UserHistoryDictionary dict =
+                new UserHistoryDictionary(context, locale, dictTypeId, sp);
+        sLangDictCache.put(locale, new SoftReference<UserHistoryDictionary>(dict));
+        return dict;
+    }
+
+    private UserHistoryDictionary(final Context context, final String locale, final int dicTypeId,
             SharedPreferences sp) {
         super(context, dicTypeId);
         mLocale = locale;
@@ -123,12 +146,13 @@ public class UserHistoryDictionary extends ExpandableDictionary {
     @Override
     public void close() {
         flushPendingWrites();
-        SettingsValues.setLastUserHistoryWriteTime(mPrefs, mLocale);
         // Don't close the database as locale changes will require it to be reopened anyway
         // Also, the database is written to somewhat frequently, so it needs to be kept alive
         // throughout the life of the process.
         // mOpenHelper.close();
-        super.close();
+        // Ignore close because we cache UserHistoryDictionary for each language. See getInstance()
+        // above.
+        // super.close();
     }
 
     /**
@@ -160,7 +184,7 @@ public class UserHistoryDictionary extends ExpandableDictionary {
         } else {
             freq = super.setBigramAndGetFrequency(word1, word2, new ForgettingCurveParams(isValid));
         }
-        synchronized (mPendingWritesLock) {
+        synchronized (mBigramList) {
             mBigramList.addBigram(word1, word2);
         }
 
@@ -168,7 +192,7 @@ public class UserHistoryDictionary extends ExpandableDictionary {
     }
 
     public boolean cancelAddingUserHistory(String word1, String word2) {
-        synchronized (mPendingWritesLock) {
+        synchronized (mBigramList) {
             if (mBigramList.removeBigram(word1, word2)) {
                 return super.removeBigram(word1, word2);
             }
@@ -180,19 +204,17 @@ public class UserHistoryDictionary extends ExpandableDictionary {
      * Schedules a background thread to write any pending words to the database.
      */
     private void flushPendingWrites() {
-        synchronized (mPendingWritesLock) {
+        synchronized (mBigramList) {
             // Nothing pending? Return
             if (mBigramList.isEmpty()) return;
             // Create a background thread to write the pending entries
-            new UpdateDbTask(sOpenHelper, mBigramList, mLocale, this).execute();
+            new UpdateDbTask(sOpenHelper, mBigramList, mLocale, this, mPrefs).execute();
-            // Create a new map for writing new entries into while the old one is written to db
-            mBigramList = new UserHistoryDictionaryBigramList();
         }
     }
 
     /** Used for testing purpose **/
     void waitUntilUpdateDBDone() {
-        synchronized (mPendingWritesLock) {
+        synchronized (mBigramList) {
             while (sUpdatingDB) {
                 try {
                     Thread.sleep(100);
@@ -205,6 +227,7 @@ public class UserHistoryDictionary extends ExpandableDictionary {
 
     @Override
     public void loadDictionaryAsync() {
+        synchronized(mBigramList) {
             final long last = SettingsValues.getLastUserHistoryWriteTime(mPrefs, mLocale);
             final long now = System.currentTimeMillis();
             // Load the words that correspond to the current input locale
@@ -232,14 +255,18 @@ public class UserHistoryDictionary extends ExpandableDictionary {
                             super.setBigramAndGetFrequency(
                                     word1, word2, new ForgettingCurveParams(fc, now, last));
                         }
-                    synchronized(mPendingWritesLock) {
                         mBigramList.addBigram(word1, word2, (byte)fc);
-                    }
                         cursor.moveToNext();
                     }
                 }
             } finally {
                 cursor.close();
+                if (PROFILE_SAVE_RESTORE) {
+                    final long diff = System.currentTimeMillis() - now;
+                    Log.w(TAG, "PROF: Load User HistoryDictionary: "
+                            + mLocale + ", " + diff + "ms.");
+                }
+            }
         }
     }
 
@@ -317,14 +344,16 @@ public class UserHistoryDictionary extends ExpandableDictionary {
         private final DatabaseHelper mDbHelper;
         private final String mLocale;
         private final UserHistoryDictionary mUserHistoryDictionary;
+        private final SharedPreferences mPrefs;
 
         public UpdateDbTask(
                 DatabaseHelper openHelper, UserHistoryDictionaryBigramList pendingWrites,
-                String locale, UserHistoryDictionary dict) {
+                String locale, UserHistoryDictionary dict, SharedPreferences prefs) {
             mBigramList = pendingWrites;
             mLocale = locale;
             mDbHelper = openHelper;
             mUserHistoryDictionary = dict;
+            mPrefs = prefs;
         }
 
         /** Prune any old data if the database is getting too big. */
@@ -363,6 +392,11 @@ public class UserHistoryDictionary extends ExpandableDictionary {
 
         @Override
         protected Void doInBackground(Void... v) {
+            synchronized(mBigramList) {
+                final long now = PROFILE_SAVE_RESTORE ? System.currentTimeMillis() : 0;
+                int profTotal = 0;
+                int profInsert = 0;
+                int profDelete = 0;
                 SQLiteDatabase db = null;
                 try {
                     db = mDbHelper.getWritableDatabase();
@@ -382,11 +416,24 @@ public class UserHistoryDictionary extends ExpandableDictionary {
                 for (String word1 : mBigramList.keySet()) {
                     final HashMap<String, Byte> word1Bigrams = mBigramList.getBigrams(word1);
                     for (String word2 : word1Bigrams.keySet()) {
-                    // Get new frequency. Do not insert shortcuts/bigrams which freq is "-1".
+                        if (PROFILE_SAVE_RESTORE) {
+                            ++profTotal;
+                        }
+                        // Get new frequency. Do not insert unigrams/bigrams which freq is "-1".
                         final int freq; // -1, or 0~255
-                    if (word1 == null) {
+                        if (word1 == null) { // unigram
                             freq = FREQUENCY_FOR_TYPED;
-                    } else {
+                            final byte prevFc = word1Bigrams.get(word2);
+                            if (prevFc == FREQUENCY_FOR_TYPED) {
+                                // No need to update since we found no changes for this entry.
+                                // Just skip to the next entry.
+                                if (DBG_SAVE_RESTORE) {
+                                    Log.d(TAG, "Skip update user history: " + word1 + "," + word2
+                                            + "," + prevFc);
+                                }
+                                continue;
+                            }
+                        } else { // bigram
                             final NextWord nw = mUserHistoryDictionary.getBigramWord(word1, word2);
                             if (nw != null) {
                                 final ForgettingCurveParams fcp = nw.getFcParams();
@@ -397,8 +444,8 @@ public class UserHistoryDictionary extends ExpandableDictionary {
                                     // No need to update since we found no changes for this entry.
                                     // Just skip to the next entry.
                                     if (DBG_SAVE_RESTORE) {
-                                    Log.d(TAG, "Skip update user history: " + word1 + "," + word2
+                                        Log.d(TAG, "Skip update user history: " + word1 + ","
-                                            + "," + prevFc);
+                                                + word2 + "," + prevFc);
                                     }
                                     continue;
                                 } else if (UserHistoryForgettingCurveUtils.
@@ -431,6 +478,9 @@ public class UserHistoryDictionary extends ExpandableDictionary {
 
                             final int pairId;
                             if (c.moveToFirst()) {
+                                if (PROFILE_SAVE_RESTORE) {
+                                    ++profDelete;
+                                }
                                 // Delete existing pair
                                 pairId = c.getInt(c.getColumnIndex(MAIN_COLUMN_ID));
                                 db.delete(FREQ_TABLE_NAME, FREQ_COLUMN_PAIR_ID + "=?",
@@ -442,6 +492,9 @@ public class UserHistoryDictionary extends ExpandableDictionary {
                                 pairId = pairIdLong.intValue();
                             }
                             if (freq > 0) {
+                                if (PROFILE_SAVE_RESTORE) {
+                                    ++profInsert;
+                                }
                                 if (DBG_SAVE_RESTORE) {
                                     Log.d(TAG, "--- Save user history: " + word1 + ", " + word2
                                             + mLocale + "," + this);
@@ -449,6 +502,9 @@ public class UserHistoryDictionary extends ExpandableDictionary {
                                 // Insert new frequency
                                 db.insert(FREQ_TABLE_NAME, null,
                                         getFrequencyContentValues(pairId, freq));
+                                // Update an existing bigram entry in mBigramList too in order to
+                                // synchronize the SQL DB and mBigramList.
+                                mBigramList.updateBigram(word1, word2, (byte)freq);
                             }
                         } finally {
                             if (c != null) {
@@ -459,9 +515,17 @@ public class UserHistoryDictionary extends ExpandableDictionary {
                 }
 
                 checkPruneData(db);
+                // Save the timestamp after we finish writing the SQL DB.
+                SettingsValues.setLastUserHistoryWriteTime(mPrefs, mLocale);
                 sUpdatingDB = false;
-
+                if (PROFILE_SAVE_RESTORE) {
+                    final long diff = System.currentTimeMillis() - now;
+                    Log.w(TAG, "PROF: Write User HistoryDictionary: " + mLocale + ", "+ diff
+                            + "ms. Total: " + profTotal + ". Insert: " + profInsert + ". Delete: "
+                            + profDelete);
+                }
                 return null;
+            } // synchronized
         }
 
         private static ContentValues getContentValues(String word1, String word2, String locale) {

java/src/com/android/inputmethod/latin/UserHistoryDictionaryBigramList.java

@@ -39,13 +39,19 @@ public class UserHistoryDictionaryBigramList {
         mBigramMap.clear();
     }
 
+    /**
+     * Called when the user typed a word.
+     */
     public void addBigram(String word1, String word2) {
         addBigram(word1, word2, FORGETTING_CURVE_INITIAL_VALUE);
     }
 
+    /**
+     * Called when loaded from the SQL DB.
+     */
     public void addBigram(String word1, String word2, byte fcValue) {
         if (UserHistoryDictionary.DBG_SAVE_RESTORE) {
-            Log.d(TAG, "--- add bigram: " + word1 + ", " + word2);
+            Log.d(TAG, "--- add bigram: " + word1 + ", " + word2 + ", " + fcValue);
         }
         final HashMap<String, Byte> map;
         if (mBigramMap.containsKey(word1)) {
@@ -60,6 +66,25 @@ public class UserHistoryDictionaryBigramList {
         }
     }
 
+    /**
+     * Called when inserted to the SQL DB.
+     */
+    public void updateBigram(String word1, String word2, byte fcValue) {
+        if (UserHistoryDictionary.DBG_SAVE_RESTORE) {
+            Log.d(TAG, "--- update bigram: " + word1 + ", " + word2 + ", " + fcValue);
+        }
+        final HashMap<String, Byte> map;
+        if (mBigramMap.containsKey(word1)) {
+            map = mBigramMap.get(word1);
+        } else {
+            return;
+        }
+        if (!map.containsKey(word2)) {
+            return;
+        }
+        map.put(word2, fcValue);
+    }
+
     public int size() {
         return mSize;
     }