Home | History | Annotate | Download | only in datamodel 
      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.android.messaging.datamodel;
     17 
     18 import android.content.Context;
     19 import android.database.sqlite.SQLiteDatabase;
     20 
     21 import com.android.messaging.Factory;
     22 import com.android.messaging.util.Assert;
     23 import com.android.messaging.util.LogUtil;
     24 
     25 public class DatabaseUpgradeHelper {
     26     private static final String TAG = LogUtil.BUGLE_DATABASE_TAG;
     27 
     28     public void doOnUpgrade(final SQLiteDatabase db, final int oldVersion, final int newVersion) {
     29         Assert.isTrue(newVersion >= oldVersion);
     30         if (oldVersion == newVersion) {
     31             return;
     32         }
     33 
     34         LogUtil.i(TAG, "Database upgrade started from version " + oldVersion + " to " + newVersion);
     35         try {
     36             doUpgradeWithExceptions(db, oldVersion, newVersion);
     37             LogUtil.i(TAG, "Finished database upgrade");
     38         } catch (final Exception ex) {
     39             LogUtil.e(TAG, "Failed to perform db upgrade from version " +
     40                     oldVersion + " to version " + newVersion, ex);
     41             DatabaseHelper.rebuildTables(db);
     42         }
     43     }
     44 
     45     public void doUpgradeWithExceptions(final SQLiteDatabase db, final int oldVersion,
     46             final int newVersion) throws Exception {
     47         int currentVersion = oldVersion;
     48         if (currentVersion < 2) {
     49             currentVersion = upgradeToVersion2(db);
     50         }
     51         // Rebuild all the views
     52         final Context context = Factory.get().getApplicationContext();
     53         DatabaseHelper.dropAllViews(db);
     54         DatabaseHelper.rebuildAllViews(new DatabaseWrapper(context, db));
     55         // Finally, check if we have arrived at the final version.
     56         checkAndUpdateVersionAtReleaseEnd(currentVersion, Integer.MAX_VALUE, newVersion);
     57     }
     58 
     59     private int upgradeToVersion2(final SQLiteDatabase db) {
     60         db.execSQL("ALTER TABLE " + DatabaseHelper.CONVERSATIONS_TABLE + " ADD COLUMN " +
     61                 DatabaseHelper.ConversationColumns.IS_ENTERPRISE + " INT DEFAULT(0)");
     62         LogUtil.i(TAG, "Ugraded database to version 2");
     63         return 2;
     64     }
     65 
     66     /**
     67      * Checks db version correctness at the end of each milestone release. If target database
     68      * version lies beyond the version range that the current release may handle, we snap the
     69      * current version to the end of the release, so that we may go on to the next release' upgrade
     70      * path. Otherwise, if target version is within reach of the current release, but we are not
     71      * at the target version, then throw an exception to force a table rebuild.
     72      */
     73     private int checkAndUpdateVersionAtReleaseEnd(final int currentVersion,
     74             final int maxVersionForRelease, final int targetVersion) throws Exception {
     75         if (maxVersionForRelease < targetVersion) {
     76             // Target version is beyond the current release. Snap to max version for the
     77             // current release so we can go on to the upgrade path for the next release.
     78             return maxVersionForRelease;
     79         }
     80 
     81         // If we are here, this means the current release' upgrade handler should upgrade to
     82         // target version...
     83         if (currentVersion != targetVersion) {
     84             // No more upgrade handlers. So we can't possibly upgrade to the final version.
     85             throw new Exception("Missing upgrade handler from version " +
     86                     currentVersion + " to version " + targetVersion);
     87         }
     88         // Upgrade succeeded.
     89         return targetVersion;
     90     }
     91 
     92     public void onDowngrade(final SQLiteDatabase db, final int oldVersion, final int newVersion) {
     93         DatabaseHelper.rebuildTables(db);
     94         LogUtil.e(TAG, "Database downgrade requested for version " +
     95                 oldVersion + " version " + newVersion + ", forcing db rebuild!");
     96     }
     97 }
     98