Switch PackageStatusStorage to XML-based storage (5f6750f9) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/timezone/PackageStatusStorage.java

+236 −194

Original line number	Diff line number	Diff line
		@@ -16,73 +16,83 @@

		package com.android.server.timezone;

		import android.content.ContentValues;
		import android.content.Context;
		import android.database.Cursor;
		import android.database.sqlite.SQLiteDatabase;
		import android.database.sqlite.SQLiteOpenHelper;
		import com.android.internal.util.FastXmlSerializer;

		import org.xmlpull.v1.XmlPullParser;
		import org.xmlpull.v1.XmlPullParserException;
		import org.xmlpull.v1.XmlSerializer;

		import android.util.AtomicFile;
		import android.util.Slog;
		import android.util.Xml;

		import java.io.File;
		import java.io.FileInputStream;
		import java.io.FileOutputStream;
		import java.io.IOException;
		import java.nio.charset.StandardCharsets;
		import java.text.ParseException;

		import static com.android.server.timezone.PackageStatus.CHECK_COMPLETED_FAILURE;
		import static com.android.server.timezone.PackageStatus.CHECK_COMPLETED_SUCCESS;
		import static com.android.server.timezone.PackageStatus.CHECK_STARTED;
		import static org.xmlpull.v1.XmlPullParser.END_DOCUMENT;
		import static org.xmlpull.v1.XmlPullParser.START_TAG;

		/**
		* Storage logic for accessing/mutating the Android system's persistent state related to time zone
		* update checking. There is expected to be a single instance and all methods synchronized on
		* {@code this} for thread safety.
		* update checking. There is expected to be a single instance. All non-private methods are thread
		* safe.
		*/
		final class PackageStatusStorage {

		private static final String TAG = "timezone.PackageStatusStorage";
		private static final String LOG_TAG = "timezone.PackageStatusStorage";

		private static final String DATABASE_NAME = "timezonepackagestatus.db";
		private static final int DATABASE_VERSION = 1;

		/** The table name. It will have a single row with _id == {@link #SINGLETON_ID} */
		private static final String TABLE = "status";
		private static final String COLUMN_ID = "_id";
		private static final String TAG_PACKAGE_STATUS = "PackageStatus";

		/**
		* Column that stores a monotonically increasing lock ID, used to detect concurrent update
		* Attribute that stores a monotonically increasing lock ID, used to detect concurrent update
		* issues without on-line locks. Incremented on every write.
		*/
		private static final String COLUMN_OPTIMISTIC_LOCK_ID = "optimistic_lock_id";

		/**
		* Column that stores the current "check status" of the time zone update application packages.
		*/
		private static final String COLUMN_CHECK_STATUS = "check_status";
		private static final String ATTRIBUTE_OPTIMISTIC_LOCK_ID = "optimisticLockId";

		/**
		* Column that stores the version of the time zone rules update application being checked / last
		* checked.
		* Attribute that stores the current "check status" of the time zone update application
		* packages.
		*/
		private static final String COLUMN_UPDATE_APP_VERSION = "update_app_package_version";
		private static final String ATTRIBUTE_CHECK_STATUS = "checkStatus";

		/**
		* Column that stores the version of the time zone rules data application being checked / last
		* checked.
		* Attribute that stores the version of the time zone rules update application being checked
		* / last checked.
		*/
		private static final String COLUMN_DATA_APP_VERSION = "data_app_package_version";
		private static final String ATTRIBUTE_UPDATE_APP_VERSION = "updateAppPackageVersion";

		/**
		* The ID of the one row.
		* Attribute that stores the version of the time zone rules data application being checked
		* / last checked.
		*/
		private static final int SINGLETON_ID = 1;
		private static final String ATTRIBUTE_DATA_APP_VERSION = "dataAppPackageVersion";

		private static final int UNKNOWN_PACKAGE_VERSION = -1;

		private final DatabaseHelper mDatabaseHelper;
		private final AtomicFile mPackageStatusFile;

		PackageStatusStorage(Context context) {
		mDatabaseHelper = new DatabaseHelper(context);
		PackageStatusStorage(File storageDir) {
		mPackageStatusFile = new AtomicFile(new File(storageDir, "packageStatus.xml"));
		if (!mPackageStatusFile.getBaseFile().exists()) {
		try {
		insertInitialPackageStatus();
		} catch (IOException e) {
		throw new IllegalStateException(e);
		}
		}
		}

		void deleteDatabaseForTests() {
		SQLiteDatabase.deleteDatabase(mDatabaseHelper.getDatabaseFile());
		void deleteFileForTests() {
		synchronized(this) {
		mPackageStatusFile.delete();
		}
		}

		/**
		@@ -93,48 +103,60 @@ final class PackageStatusStorage {
		synchronized (this) {
		try {
		return getPackageStatusInternal();
		} catch (IllegalArgumentException e) {
		// This means that data exists in the table but it was bad.
		Slog.e(TAG, "Package status invalid, resetting and retrying", e);
		} catch (ParseException e) {
		// This means that data exists in the file but it was bad.
		Slog.e(LOG_TAG, "Package status invalid, resetting and retrying", e);

		// Reset the storage so it is in a good state again.
		mDatabaseHelper.recoverFromBadData();
		recoverFromBadData(e);
		try {
		return getPackageStatusInternal();
		} catch (ParseException e2) {
		throw new IllegalStateException("Recovery from bad file failed", e2);
		}
		}
		}

		private PackageStatus getPackageStatusInternal() {
		String[] columns = {
		COLUMN_CHECK_STATUS, COLUMN_UPDATE_APP_VERSION, COLUMN_DATA_APP_VERSION
		};
		Cursor cursor = mDatabaseHelper.getReadableDatabase()
		.query(TABLE, columns, COLUMN_ID + " = ?",
		new String[] { Integer.toString(SINGLETON_ID) },
		null /* groupBy /, null / having /, null / orderBy */);
		if (cursor.getCount() != 1) {
		Slog.e(TAG, "Unable to find package status from package status row. Rows returned: "
		+ cursor.getCount());
		return null;
		}
		cursor.moveToFirst();

		// Determine check status.
		if (cursor.isNull(0)) {
		// This is normal the first time getPackageStatus() is called, or after
		// resetCheckState().
		private PackageStatus getPackageStatusInternal() throws ParseException {
		try (FileInputStream fis = mPackageStatusFile.openRead()) {
		XmlPullParser parser = parseToPackageStatusTag(fis);
		Integer checkStatus = getNullableIntAttribute(parser, ATTRIBUTE_CHECK_STATUS);
		if (checkStatus == null) {
		return null;
		}
		int checkStatus = cursor.getInt(0);
		int updateAppVersion = getIntAttribute(parser, ATTRIBUTE_UPDATE_APP_VERSION);
		int dataAppVersion = getIntAttribute(parser, ATTRIBUTE_DATA_APP_VERSION);
		return new PackageStatus(checkStatus,
		new PackageVersions(updateAppVersion, dataAppVersion));
		} catch (IOException e) {
		ParseException e2 = new ParseException("Error reading package status", 0);
		e2.initCause(e);
		throw e2;
		}
		}

		// Determine package version.
		if (cursor.isNull(1) \|\| cursor.isNull(2)) {
		Slog.e(TAG, "Package version information unexpectedly null");
		return null;
		// Callers should be synchronized(this).
		private int recoverFromBadData(Exception cause) {
		mPackageStatusFile.delete();
		try {
		return insertInitialPackageStatus();
		} catch (IOException e) {
		IllegalStateException fatal = new IllegalStateException(e);
		fatal.addSuppressed(cause);
		throw fatal;
		}
		PackageVersions packageVersions = new PackageVersions(cursor.getInt(1), cursor.getInt(2));
		}

		/** Insert the initial data, returning the optimistic lock ID */
		private int insertInitialPackageStatus() throws IOException {
		// Doesn't matter what it is, but we avoid the obvious starting value each time the data
		// is reset to ensure that old tokens are unlikely to work.
		final int initialOptimisticLockId = (int) System.currentTimeMillis();

		return new PackageStatus(checkStatus, packageVersions);
		writePackageStatusInternal(null /* status */, initialOptimisticLockId,
		null /* packageVersions */);
		return initialOptimisticLockId;
		}

		/**
		@@ -147,23 +169,29 @@ final class PackageStatusStorage {
		}

		synchronized (this) {
		Integer optimisticLockId = getCurrentOptimisticLockId();
		if (optimisticLockId == null) {
		Slog.w(TAG, "Unable to find optimistic lock ID from package status row");
		int optimisticLockId;
		try {
		optimisticLockId = getCurrentOptimisticLockId();
		} catch (ParseException e) {
		Slog.w(LOG_TAG, "Unable to find optimistic lock ID from package status");

		// Recover.
		optimisticLockId = mDatabaseHelper.recoverFromBadData();
		optimisticLockId = recoverFromBadData(e);
		}

		int newOptimisticLockId = optimisticLockId + 1;
		boolean statusRowUpdated = writeStatusRow(
		optimisticLockId, newOptimisticLockId, CHECK_STARTED, currentInstalledVersions);
		if (!statusRowUpdated) {
		Slog.e(TAG, "Unable to update status to CHECK_STARTED in package status row."
		try {
		boolean statusUpdated = writePackageStatusWithOptimisticLockCheck(
		optimisticLockId, newOptimisticLockId, CHECK_STARTED,
		currentInstalledVersions);
		if (!statusUpdated) {
		throw new IllegalStateException("Unable to update status to CHECK_STARTED."
		+ " synchronization failure?");
		return null;
		}
		return new CheckToken(newOptimisticLockId, currentInstalledVersions);
		} catch (IOException e) {
		throw new IllegalStateException(e);
		}
		}
		}

		@@ -172,19 +200,25 @@ final class PackageStatusStorage {
		*/
		void resetCheckState() {
		synchronized(this) {
		Integer optimisticLockId = getCurrentOptimisticLockId();
		if (optimisticLockId == null) {
		Slog.w(TAG, "resetCheckState: Unable to find optimistic lock ID from package"
		+ " status row");
		int optimisticLockId;
		try {
		optimisticLockId = getCurrentOptimisticLockId();
		} catch (ParseException e) {
		Slog.w(LOG_TAG, "resetCheckState: Unable to find optimistic lock ID from package"
		+ " status");
		// Attempt to recover the storage state.
		optimisticLockId = mDatabaseHelper.recoverFromBadData();
		optimisticLockId = recoverFromBadData(e);
		}

		int newOptimisticLockId = optimisticLockId + 1;
		if (!writeStatusRow(optimisticLockId, newOptimisticLockId,
		null /* status /, null / packageVersions */)) {
		Slog.e(TAG, "resetCheckState: Unable to reset package status row,"
		+ " newOptimisticLockId=" + newOptimisticLockId);
		try {
		if (!writePackageStatusWithOptimisticLockCheck(optimisticLockId,
		newOptimisticLockId, null /* status /, null / packageVersions */)) {
		throw new IllegalStateException("resetCheckState: Unable to reset package"
		+ " status, newOptimisticLockId=" + newOptimisticLockId);
		}
		} catch (IOException e) {
		throw new IllegalStateException(e);
		}
		}
		}
		@@ -199,138 +233,146 @@ final class PackageStatusStorage {
		int optimisticLockId = checkToken.mOptimisticLockId;
		int newOptimisticLockId = optimisticLockId + 1;
		int status = succeeded ? CHECK_COMPLETED_SUCCESS : CHECK_COMPLETED_FAILURE;
		return writeStatusRow(optimisticLockId, newOptimisticLockId,
		status, checkToken.mPackageVersions);
		try {
		return writePackageStatusWithOptimisticLockCheck(optimisticLockId,
		newOptimisticLockId, status, checkToken.mPackageVersions);
		} catch (IOException e) {
		throw new IllegalStateException(e);
		}
		}
		}

		// Caller should be synchronized(this)
		private Integer getCurrentOptimisticLockId() {
		final String[] columns = { COLUMN_OPTIMISTIC_LOCK_ID };
		final String querySelection = COLUMN_ID + " = ?";
		final String[] querySelectionArgs = { Integer.toString(SINGLETON_ID) };
		// Caller should be synchronized(this).
		private int getCurrentOptimisticLockId() throws ParseException {
		try (FileInputStream fis = mPackageStatusFile.openRead()) {
		XmlPullParser parser = parseToPackageStatusTag(fis);
		return getIntAttribute(parser, ATTRIBUTE_OPTIMISTIC_LOCK_ID);
		} catch (IOException e) {
		ParseException e2 = new ParseException("Unable to read file", 0);
		e2.initCause(e);
		throw e2;
		}
		}

		SQLiteDatabase database = mDatabaseHelper.getReadableDatabase();
		try (Cursor cursor = database.query(TABLE, columns, querySelection, querySelectionArgs,
		null /* groupBy /, null / having /, null / orderBy */)) {
		if (cursor.getCount() != 1) {
		Slog.w(TAG, cursor.getCount() + " rows returned, expected exactly one.");
		return null;
		/** Returns a parser or throws ParseException, never returns null. */
		private static XmlPullParser parseToPackageStatusTag(FileInputStream fis)
		throws ParseException {
		try {
		XmlPullParser parser = Xml.newPullParser();
		parser.setInput(fis, StandardCharsets.UTF_8.name());
		int type;
		while ((type = parser.next()) != END_DOCUMENT) {
		final String tag = parser.getName();
		if (type == START_TAG && TAG_PACKAGE_STATUS.equals(tag)) {
		return parser;
		}
		cursor.moveToFirst();
		return cursor.getInt(0);
		}
		throw new ParseException("Unable to find " + TAG_PACKAGE_STATUS + " tag", 0);
		} catch (XmlPullParserException e) {
		throw new IllegalStateException("Unable to configure parser", e);
		} catch (IOException e) {
		ParseException e2 = new ParseException("Error reading XML", 0);
		e.initCause(e);
		throw e2;
		}
		}

		// Caller should be synchronized(this)
		private boolean writeStatusRow(int optimisticLockId, int newOptimisticLockId, Integer status,
		PackageVersions packageVersions) {
		if ((status == null) != (packageVersions == null)) {
		throw new IllegalArgumentException(
		"Provide both status and packageVersions, or neither.");
		// Caller should be synchronized(this).
		private boolean writePackageStatusWithOptimisticLockCheck(int optimisticLockId,
		int newOptimisticLockId, Integer status, PackageVersions packageVersions)
		throws IOException {

		int currentOptimisticLockId;
		try {
		currentOptimisticLockId = getCurrentOptimisticLockId();
		if (currentOptimisticLockId != optimisticLockId) {
		return false;
		}
		} catch (ParseException e) {
		recoverFromBadData(e);
		return false;
		}

		SQLiteDatabase database = mDatabaseHelper.getWritableDatabase();
		ContentValues values = new ContentValues();
		values.put(COLUMN_OPTIMISTIC_LOCK_ID, newOptimisticLockId);
		if (status == null) {
		values.putNull(COLUMN_CHECK_STATUS);
		values.put(COLUMN_UPDATE_APP_VERSION, UNKNOWN_PACKAGE_VERSION);
		values.put(COLUMN_DATA_APP_VERSION, UNKNOWN_PACKAGE_VERSION);
		} else {
		values.put(COLUMN_CHECK_STATUS, status);
		values.put(COLUMN_UPDATE_APP_VERSION, packageVersions.mUpdateAppVersion);
		values.put(COLUMN_DATA_APP_VERSION, packageVersions.mDataAppVersion);
		writePackageStatusInternal(status, newOptimisticLockId, packageVersions);
		return true;
		}

		String updateSelection = COLUMN_ID + " = ? AND " + COLUMN_OPTIMISTIC_LOCK_ID + " = ?";
		String[] updateSelectionArgs = {
		Integer.toString(SINGLETON_ID), Integer.toString(optimisticLockId)
		};
		int count = database.update(TABLE, values, updateSelection, updateSelectionArgs);
		if (count > 1) {
		// This has to be because of corruption: there should only ever be one row.
		Slog.w(TAG, "writeStatusRow: " + count + " rows updated, expected exactly one.");
		// Reset the table.
		mDatabaseHelper.recoverFromBadData();
		// Caller should be synchronized(this).
		private void writePackageStatusInternal(Integer status, int optimisticLockId,
		PackageVersions packageVersions) throws IOException {
		if ((status == null) != (packageVersions == null)) {
		throw new IllegalArgumentException(
		"Provide both status and packageVersions, or neither.");
		}

		// 1 is the success case. 0 rows updated means the row is missing or the optimistic lock ID
		// was not as expected, this could be because of corruption but is most likely due to an
		// optimistic lock failure. Callers can decide on a case-by-case basis.
		return count == 1;
		FileOutputStream fos = null;
		try {
		fos = mPackageStatusFile.startWrite();
		XmlSerializer serializer = new FastXmlSerializer();
		serializer.setOutput(fos, StandardCharsets.UTF_8.name());
		serializer.startDocument(null /* encoding /, true / standalone */);
		final String namespace = null;
		serializer.startTag(namespace, TAG_PACKAGE_STATUS);
		String statusAttributeValue = status == null ? "" : Integer.toString(status);
		serializer.attribute(namespace, ATTRIBUTE_CHECK_STATUS, statusAttributeValue);
		serializer.attribute(namespace, ATTRIBUTE_OPTIMISTIC_LOCK_ID,
		Integer.toString(optimisticLockId));
		int updateAppVersion = status == null
		? UNKNOWN_PACKAGE_VERSION : packageVersions.mUpdateAppVersion;
		serializer.attribute(namespace, ATTRIBUTE_UPDATE_APP_VERSION,
		Integer.toString(updateAppVersion));
		int dataAppVersion = status == null
		? UNKNOWN_PACKAGE_VERSION : packageVersions.mDataAppVersion;
		serializer.attribute(namespace, ATTRIBUTE_DATA_APP_VERSION,
		Integer.toString(dataAppVersion));
		serializer.endTag(namespace, TAG_PACKAGE_STATUS);
		serializer.endDocument();
		serializer.flush();
		mPackageStatusFile.finishWrite(fos);
		} catch (IOException e) {
		if (fos != null) {
		mPackageStatusFile.failWrite(fos);
		}
		throw e;
		}

		/** Only used during tests to force an empty table. */
		void deleteRowForTests() {
		mDatabaseHelper.getWritableDatabase().delete(TABLE, null, null);
		}

		/** Only used during tests to force a known table state. */
		public void forceCheckStateForTests(int checkStatus, PackageVersions packageVersions) {
		synchronized (this) {
		try {
		int optimisticLockId = getCurrentOptimisticLockId();
		writeStatusRow(optimisticLockId, optimisticLockId, checkStatus, packageVersions);
		}

		static class DatabaseHelper extends SQLiteOpenHelper {

		private final Context mContext;

		public DatabaseHelper(Context context) {
		super(context, DATABASE_NAME, null, DATABASE_VERSION);
		mContext = context;
		writePackageStatusWithOptimisticLockCheck(optimisticLockId, optimisticLockId,
		checkStatus, packageVersions);
		} catch (IOException \| ParseException e) {
		throw new IllegalStateException(e);
		}

		@Override
		public void onCreate(SQLiteDatabase db) {
		db.execSQL("CREATE TABLE " + TABLE + " (" +
		"_id INTEGER PRIMARY KEY," +
		COLUMN_OPTIMISTIC_LOCK_ID + " INTEGER NOT NULL," +
		COLUMN_CHECK_STATUS + " INTEGER," +
		COLUMN_UPDATE_APP_VERSION + " INTEGER NOT NULL," +
		COLUMN_DATA_APP_VERSION + " INTEGER NOT NULL" +
		");");
		insertInitialRowState(db);
		}

		@Override
		public void onUpgrade(SQLiteDatabase db, int oldVersion, int currentVersion) {
		// no-op: nothing to upgrade
		}

		/** Recover the initial data row state, returning the new current optimistic lock ID */
		int recoverFromBadData() {
		// Delete the table content.
		SQLiteDatabase writableDatabase = getWritableDatabase();
		writableDatabase.delete(TABLE, null /* whereClause /, null / whereArgs */);

		// Insert the initial content.
		return insertInitialRowState(writableDatabase);
		private static Integer getNullableIntAttribute(XmlPullParser parser, String attributeName)
		throws ParseException {
		String attributeValue = parser.getAttributeValue(null, attributeName);
		try {
		if (attributeValue == null) {
		throw new ParseException("Attribute " + attributeName + " missing", 0);
		} else if (attributeValue.isEmpty()) {
		return null;
		}

		/** Insert the initial data row, returning the optimistic lock ID */
		private static int insertInitialRowState(SQLiteDatabase db) {
		// Doesn't matter what it is, but we avoid the obvious starting value each time the row
		// is reset to ensure that old tokens are unlikely to work.
		final int initialOptimisticLockId = (int) System.currentTimeMillis();

		// Insert the one row.
		ContentValues values = new ContentValues();
		values.put(COLUMN_ID, SINGLETON_ID);
		values.put(COLUMN_OPTIMISTIC_LOCK_ID, initialOptimisticLockId);
		values.putNull(COLUMN_CHECK_STATUS);
		values.put(COLUMN_UPDATE_APP_VERSION, UNKNOWN_PACKAGE_VERSION);
		values.put(COLUMN_DATA_APP_VERSION, UNKNOWN_PACKAGE_VERSION);
		long id = db.insert(TABLE, null, values);
		if (id == -1) {
		Slog.w(TAG, "insertInitialRow: could not insert initial row, id=" + id);
		return -1;
		return Integer.parseInt(attributeValue);
		} catch (NumberFormatException e) {
		throw new ParseException(
		"Bad integer for attributeName=" + attributeName + ": " + attributeValue, 0);
		}
		return initialOptimisticLockId;
		}

		File getDatabaseFile() {
		return mContext.getDatabasePath(DATABASE_NAME);
		private static int getIntAttribute(XmlPullParser parser, String attributeName)
		throws ParseException {
		Integer value = getNullableIntAttribute(parser, attributeName);
		if (value == null) {
		throw new ParseException("Missing attribute " + attributeName, 0);
		}
		return value;
		}
		}

services/core/java/com/android/server/timezone/PackageTracker.java

+10 −1

File changed.

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services/tests/servicestests/src/com/android/server/timezone/PackageStatusStorageTest.java

+15 −13

File changed.

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services/tests/servicestests/src/com/android/server/timezone/PackageTrackerTest.java

+2 −2

Original line number	Diff line number	Diff line
		@@ -71,7 +71,7 @@ public class PackageTrackerTest {

		// Using the instrumentation context means the database is created in a test app-specific
		// directory. We can use the real thing for this test.
		mPackageStatusStorage = new PackageStatusStorage(context);
		mPackageStatusStorage = new PackageStatusStorage(context.getFilesDir());

		// For other interactions with the Android framework we create a fake object.
		mFakeIntentHelper = new FakeIntentHelper();
		@@ -88,7 +88,7 @@ public class PackageTrackerTest {
		@After
		public void tearDown() throws Exception {
		if (mPackageStatusStorage != null) {
		mPackageStatusStorage.deleteDatabaseForTests();
		mPackageStatusStorage.deleteFileForTests();
		}
		}