Introduce per-user InputMethodSettings cache (2nd try)

As a preparation for concurrent multi-user support in
InputMethodManagerService, this CL introduces

  InputMethodSettingsRepository

as a per-user InputMethodSettings repository.

Note that InputMethodSettingsRepository.get(userId) has not yet used
in this CL thus there must be no user observable behavior change.

This CL was reverted once [1] because of an unexpected boot time regression in
SystemServerTiming_StartInputMethodManagerLifecycle-mean.  The major contributor
of the boot time regression should have been addressed in a more streigtforward
way [2].

 [1]: I1e6caa541620523ffdd611042c80a3b2562ae0be
      73d1ca189f272feb9a8323971bdee3b6f5126ebf
 [2]: I8e51b1ced4dc16cdca7e898885c64793665fafef
      bce89b5742781e680efac88cbc7179bf029638d9

Bug: 309837937
Bug: 333591545
Test: presubmit
Change-Id: If7d9dc5636f1bf04f02a18c84d55681914e82014
diff --git a/services/core/java/com/android/server/inputmethod/AdditionalSubtypeMapRepository.java b/services/core/java/com/android/server/inputmethod/AdditionalSubtypeMapRepository.java
index c7b60da..dd6433d 100644
--- a/services/core/java/com/android/server/inputmethod/AdditionalSubtypeMapRepository.java
+++ b/services/core/java/com/android/server/inputmethod/AdditionalSubtypeMapRepository.java
@@ -19,11 +19,13 @@
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.UserIdInt;
+import android.content.Context;
 import android.content.pm.UserInfo;
 import android.os.Handler;
 import android.util.SparseArray;
 
 import com.android.internal.annotations.GuardedBy;
+import com.android.internal.inputmethod.DirectBootAwareness;
 import com.android.server.LocalServices;
 import com.android.server.pm.UserManagerInternal;
 
@@ -67,7 +69,7 @@
         AdditionalSubtypeUtils.save(map, inputMethodMap, userId);
     }
 
-    static void initialize(@NonNull Handler handler) {
+    static void initialize(@NonNull Handler handler, @NonNull Context context) {
         final UserManagerInternal userManagerInternal =
                 LocalServices.getService(UserManagerInternal.class);
         handler.post(() -> {
@@ -79,8 +81,16 @@
                             handler.post(() -> {
                                 synchronized (ImfLock.class) {
                                     if (!sPerUserMap.contains(userId)) {
-                                        sPerUserMap.put(userId,
-                                                AdditionalSubtypeUtils.load(userId));
+                                        final AdditionalSubtypeMap additionalSubtypeMap =
+                                                AdditionalSubtypeUtils.load(userId);
+                                        sPerUserMap.put(userId, additionalSubtypeMap);
+                                        final InputMethodSettings settings =
+                                                InputMethodManagerService
+                                                        .queryInputMethodServicesInternal(context,
+                                                                userId,
+                                                                additionalSubtypeMap,
+                                                                DirectBootAwareness.AUTO);
+                                        InputMethodSettingsRepository.put(userId, settings);
                                     }
                                 }
                             });
diff --git a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
index 03a85c4..e41b47f 100644
--- a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
@@ -869,9 +869,17 @@
             if (!mSystemReady) {
                 return;
             }
-            mSettings = queryInputMethodServicesInternal(mContext, mSettings.getUserId(),
-                    AdditionalSubtypeMapRepository.get(mSettings.getUserId()),
-                    DirectBootAwareness.AUTO);
+            for (int userId : mUserManagerInternal.getUserIds()) {
+                final InputMethodSettings settings = queryInputMethodServicesInternal(
+                                mContext,
+                                userId,
+                                AdditionalSubtypeMapRepository.get(userId),
+                                DirectBootAwareness.AUTO);
+                InputMethodSettingsRepository.put(userId, settings);
+                if (userId == mSettings.getUserId()) {
+                    mSettings = settings;
+                }
+            }
             postInputMethodSettingUpdatedLocked(true /* resetDefaultEnabledIme */);
             // If the locale is changed, needs to reset the default ime
             resetDefaultImeLocked(mContext);
@@ -1118,12 +1126,15 @@
                     AdditionalSubtypeMapRepository.putAndSave(userId, newAdditionalSubtypeMap,
                             settings.getMethodMap());
                 }
-
-                if (!isCurrentUser) {
+                if (isCurrentUser
+                        && !(additionalSubtypeChanged || shouldRebuildInputMethodListLocked())) {
                     return;
                 }
 
-                if (!(additionalSubtypeChanged || shouldRebuildInputMethodListLocked())) {
+                final InputMethodSettings newSettings = queryInputMethodServicesInternal(mContext,
+                        userId, newAdditionalSubtypeMap, DirectBootAwareness.AUTO);
+                InputMethodSettingsRepository.put(userId, newSettings);
+                if (!isCurrentUser) {
                     return;
                 }
                 mSettings = queryInputMethodServicesInternal(mContext, userId,
@@ -1281,21 +1292,22 @@
 
     void onUnlockUser(@UserIdInt int userId) {
         synchronized (ImfLock.class) {
-            final int currentUserId = mSettings.getUserId();
             if (DEBUG) {
-                Slog.d(TAG, "onUnlockUser: userId=" + userId + " curUserId=" + currentUserId);
-            }
-            if (userId != currentUserId) {
-                return;
+                Slog.d(TAG, "onUnlockUser: userId=" + userId + " curUserId="
+                        + mSettings.getUserId());
             }
             if (!mSystemReady) {
                 return;
             }
-            mSettings = queryInputMethodServicesInternal(mContext, userId,
-                    AdditionalSubtypeMapRepository.get(userId), DirectBootAwareness.AUTO);
-            // We need to rebuild IMEs.
-            postInputMethodSettingUpdatedLocked(false /* resetDefaultEnabledIme */);
-            updateInputMethodsFromSettingsLocked(true /* enabledChanged */);
+            final InputMethodSettings newSettings = queryInputMethodServicesInternal(mContext,
+                    userId, AdditionalSubtypeMapRepository.get(userId), DirectBootAwareness.AUTO);
+            InputMethodSettingsRepository.put(userId, newSettings);
+            if (mSettings.getUserId() == userId) {
+                mSettings = newSettings;
+                // We need to rebuild IMEs.
+                postInputMethodSettingUpdatedLocked(false /* resetDefaultEnabledIme */);
+                updateInputMethodsFromSettingsLocked(true /* enabledChanged */);
+            }
         }
     }
 
@@ -1361,12 +1373,13 @@
 
             mShowOngoingImeSwitcherForPhones = false;
 
-            AdditionalSubtypeMapRepository.initialize(mHandler);
+            // InputMethodSettingsRepository should be initialized before buildInputMethodListLocked
+            InputMethodSettingsRepository.initialize(mHandler, mContext);
+            AdditionalSubtypeMapRepository.initialize(mHandler, mContext);
 
             final int userId = mActivityManagerInternal.getCurrentUserId();
 
-            // mSettings should be created before buildInputMethodListLocked
-            mSettings = InputMethodSettings.createEmptyMap(userId);
+            mSettings = InputMethodSettingsRepository.get(userId);
 
             mSwitchingController =
                     InputMethodSubtypeSwitchingController.createInstanceLocked(context,
@@ -1529,8 +1542,10 @@
         // and user switch would not happen at that time.
         resetCurrentMethodAndClientLocked(UnbindReason.SWITCH_USER);
 
-        mSettings = queryInputMethodServicesInternal(mContext, newUserId,
-                AdditionalSubtypeMapRepository.get(newUserId), DirectBootAwareness.AUTO);
+        final InputMethodSettings newSettings = queryInputMethodServicesInternal(mContext,
+                newUserId, AdditionalSubtypeMapRepository.get(newUserId), DirectBootAwareness.AUTO);
+        InputMethodSettingsRepository.put(newUserId, newSettings);
+        mSettings = newSettings;
         postInputMethodSettingUpdatedLocked(initialUserSwitch /* resetDefaultEnabledIme */);
         if (TextUtils.isEmpty(mSettings.getSelectedInputMethod())) {
             // This is the first time of the user switch and
@@ -1612,9 +1627,11 @@
 
                 final String defaultImiId = mSettings.getSelectedInputMethod();
                 final boolean imeSelectedOnBoot = !TextUtils.isEmpty(defaultImiId);
-                mSettings = queryInputMethodServicesInternal(mContext, currentUserId,
-                        AdditionalSubtypeMapRepository.get(mSettings.getUserId()),
+                final InputMethodSettings newSettings = queryInputMethodServicesInternal(mContext,
+                        currentUserId, AdditionalSubtypeMapRepository.get(currentUserId),
                         DirectBootAwareness.AUTO);
+                InputMethodSettingsRepository.put(currentUserId, newSettings);
+                mSettings = newSettings;
                 postInputMethodSettingUpdatedLocked(
                         !imeSelectedOnBoot /* resetDefaultEnabledIme */);
                 updateFromSettingsLocked(true);
@@ -4076,22 +4093,20 @@
 
             final var additionalSubtypeMap = AdditionalSubtypeMapRepository.get(userId);
             final boolean isCurrentUser = (mSettings.getUserId() == userId);
-            final InputMethodSettings settings = isCurrentUser
-                    ? mSettings
-                    : queryInputMethodServicesInternal(mContext, userId, additionalSubtypeMap,
-                            DirectBootAwareness.AUTO);
+            final InputMethodSettings settings = InputMethodSettingsRepository.get(userId);
             final var newAdditionalSubtypeMap = settings.getNewAdditionalSubtypeMap(
                     imiId, toBeAdded, additionalSubtypeMap, mPackageManagerInternal, callingUid);
             if (additionalSubtypeMap != newAdditionalSubtypeMap) {
                 AdditionalSubtypeMapRepository.putAndSave(userId, newAdditionalSubtypeMap,
                         settings.getMethodMap());
+                final InputMethodSettings newSettings = queryInputMethodServicesInternal(mContext,
+                        userId, AdditionalSubtypeMapRepository.get(userId),
+                        DirectBootAwareness.AUTO);
+                InputMethodSettingsRepository.put(userId, newSettings);
                 if (isCurrentUser) {
                     final long ident = Binder.clearCallingIdentity();
                     try {
-                        mSettings = queryInputMethodServicesInternal(mContext,
-                                mSettings.getUserId(),
-                                AdditionalSubtypeMapRepository.get(mSettings.getUserId()),
-                                DirectBootAwareness.AUTO);
+                        mSettings = newSettings;
                         postInputMethodSettingUpdatedLocked(false /* resetDefaultEnabledIme */);
                     } finally {
                         Binder.restoreCallingIdentity(ident);
diff --git a/services/core/java/com/android/server/inputmethod/InputMethodSettingsRepository.java b/services/core/java/com/android/server/inputmethod/InputMethodSettingsRepository.java
new file mode 100644
index 0000000..60b9a4c
--- /dev/null
+++ b/services/core/java/com/android/server/inputmethod/InputMethodSettingsRepository.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2024 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.server.inputmethod;
+
+import android.annotation.NonNull;
+import android.annotation.UserIdInt;
+import android.content.Context;
+import android.content.pm.UserInfo;
+import android.os.Handler;
+import android.util.SparseArray;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.inputmethod.DirectBootAwareness;
+import com.android.server.LocalServices;
+import com.android.server.pm.UserManagerInternal;
+
+final class InputMethodSettingsRepository {
+    @GuardedBy("ImfLock.class")
+    @NonNull
+    private static final SparseArray<InputMethodSettings> sPerUserMap = new SparseArray<>();
+
+    /**
+     * Not intended to be instantiated.
+     */
+    private InputMethodSettingsRepository() {
+    }
+
+    @NonNull
+    @GuardedBy("ImfLock.class")
+    static InputMethodSettings get(@UserIdInt int userId) {
+        final InputMethodSettings obj = sPerUserMap.get(userId);
+        if (obj != null) {
+            return obj;
+        }
+        return InputMethodSettings.createEmptyMap(userId);
+    }
+
+    @GuardedBy("ImfLock.class")
+    static void put(@UserIdInt int userId, @NonNull InputMethodSettings obj) {
+        sPerUserMap.put(userId, obj);
+    }
+
+    static void initialize(@NonNull Handler handler, @NonNull Context context) {
+        final UserManagerInternal userManagerInternal =
+                LocalServices.getService(UserManagerInternal.class);
+        handler.post(() -> {
+            userManagerInternal.addUserLifecycleListener(
+                    new UserManagerInternal.UserLifecycleListener() {
+                        @Override
+                        public void onUserRemoved(UserInfo user) {
+                            final int userId = user.id;
+                            handler.post(() -> {
+                                synchronized (ImfLock.class) {
+                                    sPerUserMap.remove(userId);
+                                }
+                            });
+                        }
+                    });
+            synchronized (ImfLock.class) {
+                for (int userId : userManagerInternal.getUserIds()) {
+                    final InputMethodSettings settings =
+                            InputMethodManagerService.queryInputMethodServicesInternal(
+                                    context,
+                                    userId,
+                                    AdditionalSubtypeMapRepository.get(userId),
+                                    DirectBootAwareness.AUTO);
+                    sPerUserMap.put(userId, settings);
+                }
+            }
+        });
+    }
+}