2 files changed, 74 insertions, 11 deletions
diff --git a/java/src/com/android/inputmethod/latin/personalization/PersonalizationHelper.java b/java/src/com/android/inputmethod/latin/personalization/PersonalizationHelper.java
index ac2fc07c2..8c5eb0aa7 100644
--- a/java/src/com/android/inputmethod/latin/personalization/PersonalizationHelper.java
+++ b/java/src/com/android/inputmethod/latin/personalization/PersonalizationHelper.java
@@ -28,32 +28,45 @@ import java.util.Locale;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+/**
+ * Helps handle and manage personalized dictionaries such as {@link UserHistoryDictionary} and
+ * {@link PersonalizationDictionary}.
+ */
 public class PersonalizationHelper {
     private static final String TAG = PersonalizationHelper.class.getSimpleName();
     private static final boolean DEBUG = false;
+
     private static final ConcurrentHashMap<String, SoftReference<UserHistoryDictionary>>
             sLangUserHistoryDictCache = new ConcurrentHashMap<>();
     private static final ConcurrentHashMap<String, SoftReference<PersonalizationDictionary>>
             sLangPersonalizationDictCache = new ConcurrentHashMap<>();
 
+    @Nonnull
     public static UserHistoryDictionary getUserHistoryDictionary(
-            final Context context, final Locale locale) {
-        final String localeStr = locale.toString();
+            final Context context, final Locale locale, @Nullable final String accountName) {
+        String lookupStr = locale.toString();
+        if (accountName != null) {
+            lookupStr += "." + accountName;
+        }
         synchronized (sLangUserHistoryDictCache) {
-            if (sLangUserHistoryDictCache.containsKey(localeStr)) {
+            if (sLangUserHistoryDictCache.containsKey(lookupStr)) {
                 final SoftReference<UserHistoryDictionary> ref =
-                        sLangUserHistoryDictCache.get(localeStr);
+                        sLangUserHistoryDictCache.get(lookupStr);
                 final UserHistoryDictionary dict = ref == null ? null : ref.get();
                 if (dict != null) {
                     if (DEBUG) {
-                        Log.w(TAG, "Use cached UserHistoryDictionary for " + locale);
+                        Log.d(TAG, "Use cached UserHistoryDictionary for " + locale +
+                                " & account" + accountName);
                     }
                     dict.reloadDictionaryIfRequired();
                     return dict;
                 }
             }
             final UserHistoryDictionary dict = new UserHistoryDictionary(context, locale);
-            sLangUserHistoryDictCache.put(localeStr, new SoftReference<>(dict));
+            sLangUserHistoryDictCache.put(lookupStr, new SoftReference<>(dict));
             return dict;
         }
     }
diff --git a/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionary.java b/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionary.java
index 58782c646..946835cbc 100644
--- a/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionary.java
@@ -17,30 +17,73 @@
 package com.android.inputmethod.latin.personalization;
 
 import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
 
 import com.android.inputmethod.annotations.ExternallyReferenced;
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.Dictionary;
 import com.android.inputmethod.latin.ExpandableBinaryDictionary;
 import com.android.inputmethod.latin.NgramContext;
 import com.android.inputmethod.latin.common.Constants;
+import com.android.inputmethod.latin.define.ProductionFlags;
+import com.android.inputmethod.latin.settings.LocalSettingsConstants;
 import com.android.inputmethod.latin.utils.DistracterFilter;
 
 import java.io.File;
 import java.util.Locale;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Locally gathers stats about the words user types and various other signals like auto-correction
  * cancellation or manual picks. This allows the keyboard to adapt to the typist over time.
  */
 public class UserHistoryDictionary extends DecayingExpandableBinaryDictionaryBase {
-    /* package */ static final String NAME = UserHistoryDictionary.class.getSimpleName();
+    static final String NAME = UserHistoryDictionary.class.getSimpleName();
 
     // TODO: Make this constructor private
-    /* package */ UserHistoryDictionary(final Context context, final Locale locale) {
-        super(context, getDictName(NAME, locale, null /* dictFile */), locale,
-                Dictionary.TYPE_USER_HISTORY, null /* dictFile */);
+    UserHistoryDictionary(final Context context, final Locale locale) {
+        super(context,
+                getUserHistoryDictName(
+                        NAME,
+                        locale,
+                        null /* dictFile */,
+                        context),
+                locale,
+                Dictionary.TYPE_USER_HISTORY,
+                null /* dictFile */);
+    }
+
+    /**
+     * @returns the name of the {@link UserHistoryDictionary}.
+     */
+    @UsedForTesting
+    static String getUserHistoryDictName(final String name, final Locale locale,
+            @Nullable final File dictFile, final Context context) {
+        if (!ProductionFlags.ENABLE_PER_ACCOUNT_USER_HISTORY_DICTIONARY) {
+            return getDictName(name, locale, dictFile);
+        }
+        return getUserHistoryDictNamePerAccount(name, locale, dictFile, context);
+    }
+
+    /**
+     * Uses the currently signed in account to determine the dictionary name.
+     */
+    private static String getUserHistoryDictNamePerAccount(final String name, final Locale locale,
+            @Nullable final File dictFile, final Context context) {
+        if (dictFile != null) {
+            return dictFile.getName();
+        }
+        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        final String account = prefs.getString(LocalSettingsConstants.PREF_ACCOUNT_NAME,
+                null /* default */);
+        String dictName = name + "." + locale.toString();
+        if (account != null) {
+            dictName += "." + account;
+        }
+        return dictName;
     }
 
     // Note: This method is called by {@link DictionaryFacilitator} using Java reflection.
@@ -48,7 +91,14 @@ public class UserHistoryDictionary extends DecayingExpandableBinaryDictionaryBas
     @ExternallyReferenced
     public static UserHistoryDictionary getDictionary(final Context context, final Locale locale,
             final File dictFile, final String dictNamePrefix) {
-        return PersonalizationHelper.getUserHistoryDictionary(context, locale);
+        final String account;
+        if (ProductionFlags.ENABLE_PER_ACCOUNT_USER_HISTORY_DICTIONARY) {
+            account = PreferenceManager.getDefaultSharedPreferences(context)
+                    .getString(LocalSettingsConstants.PREF_ACCOUNT_NAME, null /* default */);
+        } else {
+            account = null;
+        }
+        return PersonalizationHelper.getUserHistoryDictionary(context, locale, account);
     }
 
     /**