Executing the DB migration during startup instead of restore.

This allows proper execution of DB.onUpgrade task if the app updates
after the restore

Change-Id: I4c40167b30e1d7040b3a38be70d834f7b215e540

1 files changed, 137 insertions, 0 deletions

diff --git a/src/com/android/launcher3/provider/RestoreDbTask.java b/src/com/android/launcher3/provider/RestoreDbTask.java
new file mode 100644
index 000000000..9d8b6b3f4
--- /dev/null
+++ b/src/com/android/launcher3/provider/RestoreDbTask.java
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2016 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.launcher3.provider;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+
+import com.android.launcher3.LauncherAppWidgetInfo;
+import com.android.launcher3.LauncherProvider.DatabaseHelper;
+import com.android.launcher3.LauncherSettings.Favorites;
+import com.android.launcher3.Utilities;
+import com.android.launcher3.logging.FileLog;
+
+import java.io.InvalidObjectException;
+
+/**
+ * Utility class to update DB schema after it has been restored.
+ *
+ * This task is executed when Launcher starts for the first time and not immediately after restore.
+ * This helps keep the model consistent if the launcher updates between restore and first startup.
+ */
+public class RestoreDbTask {
+
+    private static final String TAG = "RestoreDbTask";
+    private static final String RESTORE_TASK_PENDING = "restore_task_pending";
+
+    private static final String INFO_COLUMN_NAME = "name";
+    private static final String INFO_COLUMN_DEFAULT_VALUE = "dflt_value";
+
+    public static boolean performRestore(DatabaseHelper helper) {
+        SQLiteDatabase db = helper.getWritableDatabase();
+        db.beginTransaction();
+        try {
+            new RestoreDbTask().sanitizeDB(helper, db);
+            db.setTransactionSuccessful();
+            return true;
+        } catch (Exception e) {
+            FileLog.e(TAG, "Failed to verify db", e);
+            return false;
+        } finally {
+            db.endTransaction();
+        }
+    }
+
+    /**
+     * Makes the following changes in the provider DB.
+     *   1. Removes all entries belonging to a managed profile as managed profiles
+     *      cannot be restored.
+     *   2. Marks all entries as restored. The flags are updated during first load or as
+     *      the restored apps get installed.
+     *   3. If the user serial for primary profile is different than that of the previous device,
+     *      update the entries to the new profile id.
+     */
+    private void sanitizeDB(DatabaseHelper helper, SQLiteDatabase db) throws Exception {
+        long oldProfileId = getDefaultProfileId(db);
+        // Delete all entries which do not belong to the main user
+        int itemsDeleted = db.delete(
+                Favorites.TABLE_NAME, "profileId != ?", new String[]{Long.toString(oldProfileId)});
+        if (itemsDeleted > 0) {
+            FileLog.d(TAG, itemsDeleted + " items belonging to a managed profile, were deleted");
+        }
+
+        // Mark all items as restored.
+        ContentValues values = new ContentValues();
+        values.put(Favorites.RESTORED, 1);
+        db.update(Favorites.TABLE_NAME, values, null, null);
+
+        // Mark widgets with appropriate restore flag
+        values.put(Favorites.RESTORED,
+                LauncherAppWidgetInfo.FLAG_ID_NOT_VALID |
+                        LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY |
+                        LauncherAppWidgetInfo.FLAG_UI_NOT_READY);
+        db.update(Favorites.TABLE_NAME, values, "itemType = ?",
+                new String[]{Integer.toString(Favorites.ITEM_TYPE_APPWIDGET)});
+
+        long myProfileId = helper.getDefaultUserSerial();
+        if (Utilities.longCompare(oldProfileId, myProfileId) != 0) {
+            FileLog.d(TAG, "Changing primary user id from " + oldProfileId + " to " + myProfileId);
+            migrateProfileId(db, myProfileId);
+        }
+    }
+
+    /**
+     * Updates profile id of all entries and changes the default value for the column.
+     */
+    protected void migrateProfileId(SQLiteDatabase db, long newProfileId) {
+        // Update existing entries.
+        ContentValues values = new ContentValues();
+        values.put(Favorites.PROFILE_ID, newProfileId);
+        db.update(Favorites.TABLE_NAME, values, null, null);
+
+        // Change default value of the column.
+        db.execSQL("ALTER TABLE favorites RENAME TO favorites_old;");
+        Favorites.addTableToDb(db, newProfileId, false);
+        db.execSQL("INSERT INTO favorites SELECT * FROM favorites_old;");
+        db.execSQL("DROP TABLE favorites_old;");
+    }
+
+    /**
+     * Returns the profile id used in the favorites table of the provided db.
+     */
+    protected long getDefaultProfileId(SQLiteDatabase db) throws Exception {
+        try (Cursor c = db.rawQuery("PRAGMA table_info (favorites)", null)){
+            int nameIndex = c.getColumnIndex(INFO_COLUMN_NAME);
+            while (c.moveToNext()) {
+                if (Favorites.PROFILE_ID.equals(c.getString(nameIndex))) {
+                    return c.getLong(c.getColumnIndex(INFO_COLUMN_DEFAULT_VALUE));
+                }
+            }
+            throw new InvalidObjectException("Table does not have a profile id column");
+        }
+    }
+
+    public static boolean isPending(Context context) {
+        return Utilities.getPrefs(context).getBoolean(RESTORE_TASK_PENDING, false);
+    }
+
+    public static void setPending(Context context, boolean isPending) {
+        Utilities.getPrefs(context).edit().putBoolean(RESTORE_TASK_PENDING, isPending).commit();
+    }
+}