Factor out code for loading and saving rollback data. (28e73230) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/rollback/RollbackManagerServiceImpl.java

+14 −196

Original line number	Diff line number	Diff line
		@@ -49,18 +49,9 @@ import com.android.internal.annotations.GuardedBy;
		import com.android.server.LocalServices;
		import com.android.server.pm.PackageManagerServiceUtils;

		import libcore.io.IoUtils;

		import org.json.JSONArray;
		import org.json.JSONException;
		import org.json.JSONObject;

		import java.io.File;
		import java.io.IOException;
		import java.io.PrintWriter;
		import java.nio.file.Files;
		import java.time.Instant;
		import java.time.format.DateTimeParseException;
		import java.time.temporal.ChronoUnit;
		import java.util.ArrayList;
		import java.util.HashMap;
		@@ -108,32 +99,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		@GuardedBy("mLock")
		private List<RollbackInfo> mRecentlyExecutedRollbacks;

		// Data for available rollbacks and recently executed rollbacks is
		// persisted in storage. Assuming the rollback data directory is
		// /data/rollback, we use the following directory structure
		// to store this data:
		// /data/rollback/
		// available/
		// XXX/
		// rollback.json
		// com.package.A/
		// base.apk
		// com.package.B/
		// base.apk
		// YYY/
		// rollback.json
		// com.package.C/
		// base.apk
		// recently_executed.json
		//
		// * XXX, YYY are random strings from Files.createTempDirectory
		// * rollback.json contains all relevant metadata for the rollback. This
		// file is not written until the rollback is made available.
		//
		// TODO: Use AtomicFile for all the .json files?
		private final File mRollbackDataDir;
		private final File mAvailableRollbacksDir;
		private final File mRecentlyExecutedRollbacksFile;
		private final RollbackStore mRollbackStore;

		private final Context mContext;
		private final HandlerThread mHandlerThread;
		@@ -143,9 +109,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		mHandlerThread = new HandlerThread("RollbackManagerServiceHandler");
		mHandlerThread.start();

		mRollbackDataDir = new File(Environment.getDataDirectory(), "rollback");
		mAvailableRollbacksDir = new File(mRollbackDataDir, "available");
		mRecentlyExecutedRollbacksFile = new File(mRollbackDataDir, "recently_executed.json");
		mRollbackStore = new RollbackStore(new File(Environment.getDataDirectory(), "rollback"));

		// Kick off loading of the rollback data from strorage in a background
		// thread.
		@@ -445,7 +409,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		for (PackageRollbackInfo info : data.packages) {
		if (info.packageName.equals(packageName)) {
		iter.remove();
		removeFile(data.backupDir);
		mRollbackStore.deleteAvailableRollback(data);
		break;
		}
		}
		@@ -484,52 +448,8 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		*/
		@GuardedBy("mLock")
		private void loadAllRollbackDataLocked() {
		mAvailableRollbacksDir.mkdirs();
		mAvailableRollbacks = new ArrayList<>();
		for (File rollbackDir : mAvailableRollbacksDir.listFiles()) {
		if (rollbackDir.isDirectory()) {
		try {
		RollbackData data = loadRollbackData(rollbackDir);
		mAvailableRollbacks.add(data);
		} catch (IOException e) {
		// Note: Deleting the rollbackDir here will cause pending
		// rollbacks to be deleted. This should only ever happen
		// if reloadPersistedData is called while there are
		// pending rollbacks. The reloadPersistedData method is
		// currently only for testing, so that should be okay.
		Log.e(TAG, "Unable to read rollback data at " + rollbackDir, e);
		removeFile(rollbackDir);
		}
		}
		}

		mRecentlyExecutedRollbacks = new ArrayList<>();
		if (mRecentlyExecutedRollbacksFile.exists()) {
		try {
		// TODO: How to cope with changes to the format of this file from
		// when RollbackStore is updated in the future?
		String jsonString = IoUtils.readFileAsString(
		mRecentlyExecutedRollbacksFile.getAbsolutePath());
		JSONObject object = new JSONObject(jsonString);
		JSONArray array = object.getJSONArray("recentlyExecuted");
		for (int i = 0; i < array.length(); ++i) {
		JSONObject element = array.getJSONObject(i);
		String packageName = element.getString("packageName");
		long higherVersionCode = element.getLong("higherVersionCode");
		long lowerVersionCode = element.getLong("lowerVersionCode");
		PackageRollbackInfo target = new PackageRollbackInfo(packageName,
		new PackageRollbackInfo.PackageVersion(higherVersionCode),
		new PackageRollbackInfo.PackageVersion(lowerVersionCode));
		RollbackInfo rollback = new RollbackInfo(target);
		mRecentlyExecutedRollbacks.add(rollback);
		}
		} catch (IOException \| JSONException e) {
		// TODO: What to do here? Surely we shouldn't just forget about
		// everything after the point of exception?
		Log.e(TAG, "Failed to read recently executed rollbacks", e);
		}
		}

		mAvailableRollbacks = mRollbackStore.loadAvailableRollbacks();
		mRecentlyExecutedRollbacks = mRollbackStore.loadRecentlyExecutedRollbacks();
		scheduleExpiration(0);
		}

		@@ -553,7 +473,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		if (info.packageName.equals(packageName)
		&& !info.higherVersion.equals(installedVersion)) {
		iter.remove();
		removeFile(data.backupDir);
		mRollbackStore.deleteAvailableRollback(data);
		break;
		}
		}
		@@ -581,91 +501,8 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		}

		if (changed) {
		saveRecentlyExecutedRollbacksLocked();
		}
		}
		}

		/**
		* Reads the metadata for a rollback from the given directory.
		* @throws IOException in case of error reading the data.
		*/
		private RollbackData loadRollbackData(File backupDir) throws IOException {
		try {
		RollbackData data = new RollbackData(backupDir);
		File rollbackJsonFile = new File(backupDir, "rollback.json");
		JSONObject dataJson = new JSONObject(
		IoUtils.readFileAsString(rollbackJsonFile.getAbsolutePath()));
		JSONArray packagesJson = dataJson.getJSONArray("packages");
		for (int i = 0; i < packagesJson.length(); ++i) {
		JSONObject infoJson = packagesJson.getJSONObject(i);
		String packageName = infoJson.getString("packageName");
		long higherVersionCode = infoJson.getLong("higherVersionCode");
		long lowerVersionCode = infoJson.getLong("lowerVersionCode");
		data.packages.add(new PackageRollbackInfo(packageName,
		new PackageRollbackInfo.PackageVersion(higherVersionCode),
		new PackageRollbackInfo.PackageVersion(lowerVersionCode)));
		}

		data.timestamp = Instant.parse(dataJson.getString("timestamp"));
		return data;
		} catch (JSONException \| DateTimeParseException e) {
		throw new IOException(e);
		}
		mRollbackStore.saveRecentlyExecutedRollbacks(mRecentlyExecutedRollbacks);
		}

		/**
		* Write the metadata for a rollback to persistent storage.
		*/
		private void saveRollbackData(RollbackData data) throws IOException {
		try {
		JSONObject dataJson = new JSONObject();
		JSONArray packagesJson = new JSONArray();
		for (PackageRollbackInfo info : data.packages) {
		JSONObject infoJson = new JSONObject();
		infoJson.put("packageName", info.packageName);
		infoJson.put("higherVersionCode", info.higherVersion.versionCode);
		infoJson.put("lowerVersionCode", info.lowerVersion.versionCode);
		packagesJson.put(infoJson);
		}
		dataJson.put("packages", packagesJson);
		dataJson.put("timestamp", data.timestamp.toString());

		PrintWriter pw = new PrintWriter(new File(data.backupDir, "rollback.json"));
		pw.println(dataJson.toString());
		pw.close();
		} catch (JSONException e) {
		throw new IOException(e);
		}
		}

		/**
		* Write the list of recently executed rollbacks to storage.
		* Note: This happens while mLock is held, which should be okay because we
		* expect executed rollbacks to be modified only in exceptional cases.
		*/
		@GuardedBy("mLock")
		private void saveRecentlyExecutedRollbacksLocked() {
		try {
		JSONObject json = new JSONObject();
		JSONArray array = new JSONArray();
		json.put("recentlyExecuted", array);

		for (int i = 0; i < mRecentlyExecutedRollbacks.size(); ++i) {
		RollbackInfo rollback = mRecentlyExecutedRollbacks.get(i);
		JSONObject element = new JSONObject();
		element.put("packageName", rollback.targetPackage.packageName);
		element.put("higherVersionCode", rollback.targetPackage.higherVersion.versionCode);
		element.put("lowerVersionCode", rollback.targetPackage.lowerVersion.versionCode);
		array.put(element);
		}

		PrintWriter pw = new PrintWriter(mRecentlyExecutedRollbacksFile);
		pw.println(json.toString());
		pw.close();
		} catch (IOException \| JSONException e) {
		// TODO: What to do here?
		Log.e(TAG, "Failed to save recently executed rollbacks", e);
		}
		}

		@@ -678,7 +515,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		synchronized (mLock) {
		ensureRollbackDataLoadedLocked();
		mRecentlyExecutedRollbacks.add(rollback);
		saveRecentlyExecutedRollbacksLocked();
		mRollbackStore.saveRecentlyExecutedRollbacks(mRecentlyExecutedRollbacks);
		}
		}

		@@ -729,7 +566,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		RollbackData data = iter.next();
		if (!now.isBefore(data.timestamp.plusMillis(ROLLBACK_LIFETIME_DURATION_MILLIS))) {
		iter.remove();
		removeFile(data.backupDir);
		mRollbackStore.deleteAvailableRollback(data);
		} else if (oldest == null \|\| oldest.isAfter(data.timestamp)) {
		oldest = data.timestamp;
		}
		@@ -855,9 +692,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		mChildSessions.put(childSessionId, parentSessionId);
		data = mPendingRollbacks.get(parentSessionId);
		if (data == null) {
		File backupDir = Files.createTempDirectory(
		mAvailableRollbacksDir.toPath(), null).toFile();
		data = new RollbackData(backupDir);
		data = mRollbackStore.createAvailableRollback();
		mPendingRollbacks.put(parentSessionId, data);
		}
		data.packages.add(info);
		@@ -867,14 +702,13 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		return false;
		}

		File packageDir = new File(data.backupDir, packageName);
		File packageDir = mRollbackStore.packageCodePathForAvailableRollback(data, packageName);
		packageDir.mkdirs();

		// TODO: Copy by hard link instead to save on cpu and storage space?
		int status = PackageManagerServiceUtils.copyPackage(installedPackage.codePath, packageDir);
		if (status != PackageManager.INSTALL_SUCCEEDED) {
		Log.e(TAG, "Unable to copy package for rollback for " + packageName);
		removeFile(packageDir);
		return false;
		}

		@@ -910,22 +744,6 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		}
		}

		/**
		* Deletes a file completely.
		* If the file is a directory, its contents are deleted as well.
		* Has no effect if the directory does not exist.
		*/
		private void removeFile(File file) {
		if (file.isDirectory()) {
		for (File child : file.listFiles()) {
		removeFile(child);
		}
		}
		if (file.exists()) {
		file.delete();
		}
		}

		/**
		* Gets the version of the package currently installed.
		* Returns null if the package is not currently installed.
		@@ -972,7 +790,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		try {
		data.timestamp = Instant.now();

		saveRollbackData(data);
		mRollbackStore.saveAvailableRollback(data);
		synchronized (mLock) {
		// Note: There is a small window of time between when
		// the session has been committed by the package
		@@ -991,12 +809,12 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		scheduleExpiration(ROLLBACK_LIFETIME_DURATION_MILLIS);
		} catch (IOException e) {
		Log.e(TAG, "Unable to enable rollback", e);
		removeFile(data.backupDir);
		mRollbackStore.deleteAvailableRollback(data);
		}
		} else {
		// The install session was aborted, clean up the pending
		// install.
		removeFile(data.backupDir);
		mRollbackStore.deleteAvailableRollback(data);
		}
		}
		}

services/core/java/com/android/server/rollback/RollbackStore.java

0 → 100644

+254 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2018 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.server.rollback;

		import android.content.rollback.PackageRollbackInfo;
		import android.content.rollback.RollbackInfo;
		import android.util.Log;

		import libcore.io.IoUtils;

		import org.json.JSONArray;
		import org.json.JSONException;
		import org.json.JSONObject;

		import java.io.File;
		import java.io.IOException;
		import java.io.PrintWriter;
		import java.nio.file.Files;
		import java.time.Instant;
		import java.time.format.DateTimeParseException;
		import java.util.ArrayList;
		import java.util.List;

		/**
		* Helper class for loading and saving rollback data to persistent storage.
		*/
		class RollbackStore {
		private static final String TAG = "RollbackManager";

		// Assuming the rollback data directory is /data/rollback, we use the
		// following directory structure to store persisted data for available and
		// recently executed rollbacks:
		// /data/rollback/
		// available/
		// XXX/
		// rollback.json
		// com.package.A/
		// base.apk
		// com.package.B/
		// base.apk
		// YYY/
		// rollback.json
		// com.package.C/
		// base.apk
		// recently_executed.json
		//
		// * XXX, YYY are random strings from Files.createTempDirectory
		// * rollback.json contains all relevant metadata for the rollback. This
		// file is not written until the rollback is made available.
		//
		// TODO: Use AtomicFile for all the .json files?
		private final File mRollbackDataDir;
		private final File mAvailableRollbacksDir;
		private final File mRecentlyExecutedRollbacksFile;

		RollbackStore(File rollbackDataDir) {
		mRollbackDataDir = rollbackDataDir;
		mAvailableRollbacksDir = new File(mRollbackDataDir, "available");
		mRecentlyExecutedRollbacksFile = new File(mRollbackDataDir, "recently_executed.json");
		}

		/**
		* Reads the list of available rollbacks from persistent storage.
		*/
		List<RollbackData> loadAvailableRollbacks() {
		List<RollbackData> availableRollbacks = new ArrayList<>();
		mAvailableRollbacksDir.mkdirs();
		for (File rollbackDir : mAvailableRollbacksDir.listFiles()) {
		if (rollbackDir.isDirectory()) {
		try {
		RollbackData data = loadRollbackData(rollbackDir);
		availableRollbacks.add(data);
		} catch (IOException e) {
		// Note: Deleting the rollbackDir here will cause pending
		// rollbacks to be deleted. This should only ever happen
		// if reloadPersistedData is called while there are
		// pending rollbacks. The reloadPersistedData method is
		// currently only for testing, so that should be okay.
		Log.e(TAG, "Unable to read rollback data at " + rollbackDir, e);
		removeFile(rollbackDir);
		}
		}
		}
		return availableRollbacks;
		}

		/**
		* Reads the list of recently executed rollbacks from persistent storage.
		*/
		List<RollbackInfo> loadRecentlyExecutedRollbacks() {
		List<RollbackInfo> recentlyExecutedRollbacks = new ArrayList<>();
		if (mRecentlyExecutedRollbacksFile.exists()) {
		try {
		// TODO: How to cope with changes to the format of this file from
		// when RollbackStore is updated in the future?
		String jsonString = IoUtils.readFileAsString(
		mRecentlyExecutedRollbacksFile.getAbsolutePath());
		JSONObject object = new JSONObject(jsonString);
		JSONArray array = object.getJSONArray("recentlyExecuted");
		for (int i = 0; i < array.length(); ++i) {
		JSONObject element = array.getJSONObject(i);
		String packageName = element.getString("packageName");
		long higherVersionCode = element.getLong("higherVersionCode");
		long lowerVersionCode = element.getLong("lowerVersionCode");
		PackageRollbackInfo target = new PackageRollbackInfo(packageName,
		new PackageRollbackInfo.PackageVersion(higherVersionCode),
		new PackageRollbackInfo.PackageVersion(lowerVersionCode));
		RollbackInfo rollback = new RollbackInfo(target);
		recentlyExecutedRollbacks.add(rollback);
		}
		} catch (IOException \| JSONException e) {
		// TODO: What to do here? Surely we shouldn't just forget about
		// everything after the point of exception?
		Log.e(TAG, "Failed to read recently executed rollbacks", e);
		}
		}

		return recentlyExecutedRollbacks;
		}

		/**
		* Creates a new RollbackData instance with backupDir assigned.
		*/
		RollbackData createAvailableRollback() throws IOException {
		File backupDir = Files.createTempDirectory(mAvailableRollbacksDir.toPath(), null).toFile();
		return new RollbackData(backupDir);
		}

		/**
		* Returns the directory where the code for a package should be stored for
		* given rollback <code>data</code> and <code>packageName</code>.
		*/
		File packageCodePathForAvailableRollback(RollbackData data, String packageName) {
		return new File(data.backupDir, packageName);
		}

		/**
		* Writes the metadata for an available rollback to persistent storage.
		*/
		void saveAvailableRollback(RollbackData data) throws IOException {
		try {
		JSONObject dataJson = new JSONObject();
		JSONArray packagesJson = new JSONArray();
		for (PackageRollbackInfo info : data.packages) {
		JSONObject infoJson = new JSONObject();
		infoJson.put("packageName", info.packageName);
		infoJson.put("higherVersionCode", info.higherVersion.versionCode);
		infoJson.put("lowerVersionCode", info.lowerVersion.versionCode);
		packagesJson.put(infoJson);
		}
		dataJson.put("packages", packagesJson);
		dataJson.put("timestamp", data.timestamp.toString());

		PrintWriter pw = new PrintWriter(new File(data.backupDir, "rollback.json"));
		pw.println(dataJson.toString());
		pw.close();
		} catch (JSONException e) {
		throw new IOException(e);
		}
		}

		/**
		* Removes all persistant storage associated with the given available
		* rollback.
		*/
		void deleteAvailableRollback(RollbackData data) {
		removeFile(data.backupDir);
		}

		/**
		* Writes the list of recently executed rollbacks to storage.
		*/
		void saveRecentlyExecutedRollbacks(List<RollbackInfo> recentlyExecutedRollbacks) {
		try {
		JSONObject json = new JSONObject();
		JSONArray array = new JSONArray();
		json.put("recentlyExecuted", array);

		for (int i = 0; i < recentlyExecutedRollbacks.size(); ++i) {
		RollbackInfo rollback = recentlyExecutedRollbacks.get(i);
		JSONObject element = new JSONObject();
		element.put("packageName", rollback.targetPackage.packageName);
		element.put("higherVersionCode", rollback.targetPackage.higherVersion.versionCode);
		element.put("lowerVersionCode", rollback.targetPackage.lowerVersion.versionCode);
		array.put(element);
		}

		PrintWriter pw = new PrintWriter(mRecentlyExecutedRollbacksFile);
		pw.println(json.toString());
		pw.close();
		} catch (IOException \| JSONException e) {
		// TODO: What to do here?
		Log.e(TAG, "Failed to save recently executed rollbacks", e);
		}
		}

		/**
		* Reads the metadata for a rollback from the given directory.
		* @throws IOException in case of error reading the data.
		*/
		private RollbackData loadRollbackData(File backupDir) throws IOException {
		try {
		RollbackData data = new RollbackData(backupDir);
		File rollbackJsonFile = new File(backupDir, "rollback.json");
		JSONObject dataJson = new JSONObject(
		IoUtils.readFileAsString(rollbackJsonFile.getAbsolutePath()));
		JSONArray packagesJson = dataJson.getJSONArray("packages");
		for (int i = 0; i < packagesJson.length(); ++i) {
		JSONObject infoJson = packagesJson.getJSONObject(i);
		String packageName = infoJson.getString("packageName");
		long higherVersionCode = infoJson.getLong("higherVersionCode");
		long lowerVersionCode = infoJson.getLong("lowerVersionCode");
		data.packages.add(new PackageRollbackInfo(packageName,
		new PackageRollbackInfo.PackageVersion(higherVersionCode),
		new PackageRollbackInfo.PackageVersion(lowerVersionCode)));
		}

		data.timestamp = Instant.parse(dataJson.getString("timestamp"));
		return data;
		} catch (JSONException \| DateTimeParseException e) {
		throw new IOException(e);
		}
		}

		/**
		* Deletes a file completely.
		* If the file is a directory, its contents are deleted as well.
		* Has no effect if the directory does not exist.
		*/
		private void removeFile(File file) {
		if (file.isDirectory()) {
		for (File child : file.listFiles()) {
		removeFile(child);
		}
		}
		if (file.exists()) {
		file.delete();
		}
		}
		}