Adding support for DB downgrade
Adding a schema file for handling DB downgrade. This schema file is part of
the backup/restore set, and hence is available on a device with lower app version.
Bug: 37257575
Change-Id: I69c8ef5f28d5209be6e6679412c7459d4eeda5d0
diff --git a/src/com/android/launcher3/LauncherProvider.java b/src/com/android/launcher3/LauncherProvider.java
index bd53b4d..c84a431 100644
--- a/src/com/android/launcher3/LauncherProvider.java
+++ b/src/com/android/launcher3/LauncherProvider.java
@@ -56,6 +56,7 @@
import com.android.launcher3.dynamicui.ExtractionUtils;
import com.android.launcher3.graphics.IconShapeOverride;
import com.android.launcher3.logging.FileLog;
+import com.android.launcher3.model.DbDowngradeHelper;
import com.android.launcher3.provider.LauncherDbUtils;
import com.android.launcher3.provider.LauncherDbUtils.SQLiteTransaction;
import com.android.launcher3.provider.RestoreDbTask;
@@ -64,6 +65,7 @@
import com.android.launcher3.util.Preconditions;
import com.android.launcher3.util.Thunk;
+import java.io.File;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.lang.reflect.Method;
@@ -77,18 +79,12 @@
private static final String TAG = "LauncherProvider";
private static final boolean LOGD = false;
+ private static final String DOWNGRADE_SCHEMA_FILE = "downgrade_schema.json";
+
/**
* Represents the schema of the database. Changes in scheme need not be backwards compatible.
*/
- private static final int SCHEMA_VERSION = 27;
- /**
- * Represents the actual data. It could include additional validations and normalizations added
- * overtime. These must be backwards compatible, else we risk breaking old devices during
- * restore or binary version downgrade.
- */
- private static final int DATA_VERSION = 3;
-
- private static final String PREF_KEY_DATA_VERISON = "provider_data_version";
+ public static final int SCHEMA_VERSION = 27;
public static final String AUTHORITY = (BuildConfig.APPLICATION_ID + ".settings").intern();
@@ -703,47 +699,30 @@
@Override
public void onOpen(SQLiteDatabase db) {
super.onOpen(db);
- SharedPreferences prefs = mContext
- .getSharedPreferences(LauncherFiles.DEVICE_PREFERENCES_KEY, 0);
- int oldVersion = prefs.getInt(PREF_KEY_DATA_VERISON, 0);
- if (oldVersion != DATA_VERSION) {
- // Only run the data upgrade path for an existing db.
- if (!Utilities.getPrefs(mContext).getBoolean(EMPTY_DATABASE_CREATED, false)) {
- try (SQLiteTransaction t = new SQLiteTransaction(db)) {
- onDataUpgrade(db, oldVersion);
- t.commit();
- } catch (Exception e) {
- Log.d(TAG, "Error updating data version, ignoring", e);
- return;
- }
- }
- prefs.edit().putInt(PREF_KEY_DATA_VERISON, DATA_VERSION).apply();
+
+ File schemaFile = mContext.getFileStreamPath(DOWNGRADE_SCHEMA_FILE);
+ if (!schemaFile.exists()) {
+ handleOneTimeDataUpgrade(db);
}
+ DbDowngradeHelper.updateSchemaFile(schemaFile, SCHEMA_VERSION, mContext,
+ R.raw.downgrade_schema);
}
/**
- * Called when the data is updated as part of app update. It can be called multiple times
- * with old version, even though it had been run before. The changes made here must be
- * backwards compatible, else we risk breaking old devices during restore or binary
- * version downgrade.
+ * One-time data updated before support of onDowngrade was added. This update is backwards
+ * compatible and can safely be run multiple times.
+ * Note: No new logic should be added here after release, as the new logic might not get
+ * executed on an existing device.
+ * TODO: Move this to db upgrade path, once the downgrade path is released.
*/
- protected void onDataUpgrade(SQLiteDatabase db, int oldVersion) {
- switch (oldVersion) {
- case 0:
- case 1: {
- // Remove "profile extra"
- UserManagerCompat um = UserManagerCompat.getInstance(mContext);
- for (UserHandle user : um.getUserProfiles()) {
- long serial = um.getSerialNumberForUser(user);
- String sql = "update favorites set intent = replace(intent, "
- + "';l.profile=" + serial + ";', ';') where itemType = 0;";
- db.execSQL(sql);
- }
- }
- case 2:
- case 3:
- // data updated
- return;
+ protected void handleOneTimeDataUpgrade(SQLiteDatabase db) {
+ // Remove "profile extra"
+ UserManagerCompat um = UserManagerCompat.getInstance(mContext);
+ for (UserHandle user : um.getUserProfiles()) {
+ long serial = um.getSerialNumberForUser(user);
+ String sql = "update favorites set intent = replace(intent, "
+ + "';l.profile=" + serial + ";', ';') where itemType = 0;";
+ db.execSQL(sql);
}
}
@@ -850,15 +829,14 @@
@Override
public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
- if (oldVersion == 28 && newVersion == 27) {
- // TODO: remove this check. This is only applicable for internal development/testing
- // and for any released version of Launcher.
- return;
+ try {
+ DbDowngradeHelper.parse(mContext.getFileStreamPath(DOWNGRADE_SCHEMA_FILE))
+ .onDowngrade(db, oldVersion, newVersion);
+ } catch (Exception e) {
+ Log.d(TAG, "Unable to downgrade from: " + oldVersion + " to " + newVersion +
+ ". Wiping databse.", e);
+ createEmptyDB(db);
}
- // This shouldn't happen -- throw our hands up in the air and start over.
- Log.w(TAG, "Database version downgrade from: " + oldVersion + " to " + newVersion +
- ". Wiping databse.");
- createEmptyDB(db);
}
/**
diff --git a/src/com/android/launcher3/model/DbDowngradeHelper.java b/src/com/android/launcher3/model/DbDowngradeHelper.java
new file mode 100644
index 0000000..cd86b72
--- /dev/null
+++ b/src/com/android/launcher3/model/DbDowngradeHelper.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2017 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.model;
+
+import android.content.Context;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteException;
+import android.util.Log;
+import android.util.SparseArray;
+
+import com.android.launcher3.provider.LauncherDbUtils.SQLiteTransaction;
+import com.android.launcher3.util.IOUtils;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Collections;
+
+/**
+ * Utility class to handle DB downgrade
+ */
+public class DbDowngradeHelper {
+
+ private static final String TAG = "DbDowngradeHelper";
+
+ private static final String KEY_VERSION = "version";
+ private static final String KEY_DOWNGRADE_TO = "downgrade_to_";
+
+ private final SparseArray<String[]> mStatements = new SparseArray<>();
+ public final int version;
+
+ private DbDowngradeHelper(int version) {
+ this.version = version;
+ }
+
+ public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+ ArrayList<String> allCommands = new ArrayList<>();
+
+ for (int i = oldVersion - 1; i >= newVersion; i--) {
+ String[] commands = mStatements.get(i);
+ if (commands == null) {
+ throw new SQLiteException("Downgrade path not supported to version " + i);
+ }
+ Collections.addAll(allCommands, commands);
+ }
+
+ try (SQLiteTransaction t = new SQLiteTransaction(db)) {
+ for (String sql : allCommands) {
+ db.execSQL(sql);
+ }
+ t.commit();
+ }
+ }
+
+ public static DbDowngradeHelper parse(File file) throws JSONException, IOException {
+ JSONObject obj = new JSONObject(new String(IOUtils.toByteArray(file)));
+ DbDowngradeHelper helper = new DbDowngradeHelper(obj.getInt(KEY_VERSION));
+ for (int version = helper.version - 1; version > 0; version--) {
+ if (obj.has(KEY_DOWNGRADE_TO + version)) {
+ JSONArray statements = obj.getJSONArray(KEY_DOWNGRADE_TO + version);
+ String[] parsed = new String[statements.length()];
+ for (int i = 0; i < parsed.length; i++) {
+ parsed[i] = statements.getString(i);
+ }
+ helper.mStatements.put(version, parsed);
+ }
+ }
+ return helper;
+ }
+
+ public static void updateSchemaFile(File schemaFile, int expectedVersion,
+ Context context, int schemaResId) {
+ try {
+ if (DbDowngradeHelper.parse(schemaFile).version >= expectedVersion) {
+ return;
+ }
+ } catch (Exception e) {
+ // Schema error
+ }
+
+ // Write the updated schema
+ try (FileOutputStream fos = new FileOutputStream(schemaFile);
+ InputStream in = context.getResources().openRawResource(schemaResId)) {
+ IOUtils.copy(in, fos);
+ } catch (IOException e) {
+ Log.e(TAG, "Error writing schema file", e);
+ }
+ }
+}
diff --git a/src/com/android/launcher3/provider/LauncherDbUtils.java b/src/com/android/launcher3/provider/LauncherDbUtils.java
index 6325040..74373d3 100644
--- a/src/com/android/launcher3/provider/LauncherDbUtils.java
+++ b/src/com/android/launcher3/provider/LauncherDbUtils.java
@@ -52,6 +52,7 @@
if (screenIds.isEmpty()) {
// No update needed
+ t.commit();
return true;
}
if (screenIds.get(0) != 0) {
@@ -71,6 +72,7 @@
if (DatabaseUtils.queryNumEntries(db, Favorites.TABLE_NAME,
"container = -100 and screen = 0 and cellY = 0") == 0) {
// First row is empty, no need to migrate.
+ t.commit();
return true;
}
diff --git a/src/com/android/launcher3/util/IOUtils.java b/src/com/android/launcher3/util/IOUtils.java
new file mode 100644
index 0000000..77c21fe
--- /dev/null
+++ b/src/com/android/launcher3/util/IOUtils.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2017 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.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Supports various IO utility functions
+ */
+public class IOUtils {
+
+ private static final int BUF_SIZE = 0x1000; // 4K
+
+ public static byte[] toByteArray(File file) throws IOException {
+ try (InputStream in = new FileInputStream(file)) {
+ return toByteArray(in);
+ }
+ }
+
+ public static byte[] toByteArray(InputStream in) throws IOException {
+ ByteArrayOutputStream out = new ByteArrayOutputStream();
+ copy(in, out);
+ return out.toByteArray();
+ }
+
+ public static long copy(InputStream from, OutputStream to) throws IOException {
+ byte[] buf = new byte[BUF_SIZE];
+ long total = 0;
+ int r;
+ while ((r = from.read(buf)) != -1) {
+ to.write(buf, 0, r);
+ total += r;
+ }
+ return total;
+ }
+}