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 
doOnUpgrade(final SQLiteDatabase db, final int oldVersion, final int newVersion)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 
doUpgradeWithExceptions(final SQLiteDatabase db, final int oldVersion, final int newVersion)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 
upgradeToVersion2(final SQLiteDatabase db)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      */
checkAndUpdateVersionAtReleaseEnd(final int currentVersion, final int maxVersionForRelease, final int targetVersion)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 
onDowngrade(final SQLiteDatabase db, final int oldVersion, final int newVersion)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