Implement a new stats file for dynamic code usage. (9c325c22) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/pm/dex/PackageDynamicCodeLoading.java

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		/*
		* Copyright 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.pm.dex;

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

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.util.FastPrintWriter;
		import com.android.server.pm.AbstractStatsBase;

		import libcore.io.IoUtils;

		import java.io.BufferedReader;
		import java.io.FileInputStream;
		import java.io.FileNotFoundException;
		import java.io.FileOutputStream;
		import java.io.IOException;
		import java.io.InputStream;
		import java.io.InputStreamReader;
		import java.io.OutputStream;
		import java.io.PrintWriter;
		import java.util.Arrays;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.Iterator;
		import java.util.Map;
		import java.util.Map.Entry;
		import java.util.Set;
		import java.util.regex.Matcher;
		import java.util.regex.Pattern;

		/**
		* Stats file which stores information about secondary code files that are dynamically loaded.
		*/
		class PackageDynamicCodeLoading extends AbstractStatsBase<Void> {
		// Type code to indicate a secondary file containing DEX code. (The char value is how it
		// is represented in the text file format.)
		static final int FILE_TYPE_DEX = 'D';

		private static final String TAG = "PackageDynamicCodeLoading";

		private static final String FILE_VERSION_HEADER = "DCL1";
		private static final String PACKAGE_PREFIX = "P:";

		private static final char FIELD_SEPARATOR = ':';
		private static final String PACKAGE_SEPARATOR = ",";

		/**
		* Regular expression to match the expected format of an input line describing one file.
		* <p>Example: {@code D:10:package.name1,package.name2:/escaped/path}
		* <p>The capturing groups are the file type, user ID, loading packages and escaped file path
		* (in that order).
		* <p>See {@link #write(OutputStream, Map)} below for more details of the format.
		*/
		private static final Pattern PACKAGE_LINE_PATTERN =
		Pattern.compile("([A-Z]):([0-9]+):([^:]):(.)");

		private final Object mLock = new Object();

		// Map from package name to data about loading of dynamic code files owned by that package.
		// (Apps may load code files owned by other packages, subject to various access
		// constraints.)
		// Any PackageDynamicCode in this map will be non-empty.
		@GuardedBy("mLock")
		private Map<String, PackageDynamicCode> mPackageMap = new HashMap<>();

		PackageDynamicCodeLoading() {
		super("package-dcl.list", "PackageDynamicCodeLoading_DiskWriter", false);
		}

		/**
		* Record dynamic code loading from a file.
		*
		* Note this is called when an app loads dex files and as such it should return
		* as fast as possible.
		*
		* @param owningPackageName the package owning the file path
		* @param filePath the path of the dex files being loaded
		* @param fileType the type of code loading
		* @param ownerUserId the user id which runs the code loading the file
		* @param loadingPackageName the package performing the load
		* @return whether new information has been recorded
		* @throw IllegalArgumentException if clearly invalid information is detected
		*/
		boolean record(String owningPackageName, String filePath, int fileType, int ownerUserId,
		String loadingPackageName) {
		if (fileType != FILE_TYPE_DEX) {
		throw new IllegalArgumentException("Bad file type: " + fileType);
		}
		synchronized (mLock) {
		PackageDynamicCode packageInfo = mPackageMap.get(owningPackageName);
		if (packageInfo == null) {
		packageInfo = new PackageDynamicCode();
		mPackageMap.put(owningPackageName, packageInfo);
		}
		return packageInfo.add(filePath, (char) fileType, ownerUserId, loadingPackageName);
		}
		}

		/**
		* Return all packages that contain records of secondary dex files. (Note that data updates
		* asynchronously, so {@link #getPackageDynamicCodeInfo} may still return null if passed
		* one of these package names.)
		*/
		Set<String> getAllPackagesWithDynamicCodeLoading() {
		synchronized (mLock) {
		return new HashSet<>(mPackageMap.keySet());
		}
		}

		/**
		* Return information about the dynamic code file usage of the specified package,
		* or null if there is currently no usage information. The object returned is a copy of the
		* live information that is not updated.
		*/
		PackageDynamicCode getPackageDynamicCodeInfo(String packageName) {
		synchronized (mLock) {
		PackageDynamicCode info = mPackageMap.get(packageName);
		return info == null ? null : new PackageDynamicCode(info);
		}
		}

		/**
		* Remove all information about all packages.
		*/
		void clear() {
		synchronized (mLock) {
		mPackageMap.clear();
		}
		}

		/**
		* Remove the data associated with package {@code packageName}. Affects all users.
		* @return true if the package usage was found and removed successfully
		*/
		boolean removePackage(String packageName) {
		synchronized (mLock) {
		return mPackageMap.remove(packageName) != null;
		}
		}

		/**
		* Remove all the records about package {@code packageName} belonging to user {@code userId}.
		* @return whether any data was actually removed
		*/
		boolean removeUserPackage(String packageName, int userId) {
		synchronized (mLock) {
		PackageDynamicCode packageDynamicCode = mPackageMap.get(packageName);
		if (packageDynamicCode == null) {
		return false;
		}
		if (packageDynamicCode.removeUser(userId)) {
		if (packageDynamicCode.mFileUsageMap.isEmpty()) {
		mPackageMap.remove(packageName);
		}
		return true;
		} else {
		return false;
		}
		}
		}

		/**
		* Remove the specified dynamic code file record belonging to the package {@code packageName}
		* and user {@code userId}.
		* @return whether data was actually removed
		*/
		boolean removeFile(String packageName, String filePath, int userId) {
		synchronized (mLock) {
		PackageDynamicCode packageDynamicCode = mPackageMap.get(packageName);
		if (packageDynamicCode == null) {
		return false;
		}
		if (packageDynamicCode.removeFile(filePath, userId)) {
		if (packageDynamicCode.mFileUsageMap.isEmpty()) {
		mPackageMap.remove(packageName);
		}
		return true;
		} else {
		return false;
		}
		}
		}

		/**
		* Syncs data with the set of installed packages. Data about packages that are no longer
		* installed is removed.
		* @param packageToUsersMap a map from all existing package names to the users who have the
		* package installed
		*/
		void syncData(Map<String, Set<Integer>> packageToUsersMap) {
		synchronized (mLock) {
		Iterator<Entry<String, PackageDynamicCode>> it = mPackageMap.entrySet().iterator();
		while (it.hasNext()) {
		Entry<String, PackageDynamicCode> entry = it.next();
		Set<Integer> packageUsers = packageToUsersMap.get(entry.getKey());
		if (packageUsers == null) {
		it.remove();
		} else {
		PackageDynamicCode packageDynamicCode = entry.getValue();
		packageDynamicCode.syncData(packageToUsersMap, packageUsers);
		if (packageDynamicCode.mFileUsageMap.isEmpty()) {
		it.remove();
		}
		}
		}
		}
		}

		/**
		* Request that data be written to persistent file at the next time allowed by write-limiting.
		*/
		void maybeWriteAsync() {
		super.maybeWriteAsync(null);
		}

		/**
		* Writes data to persistent file immediately.
		*/
		void writeNow() {
		super.writeNow(null);
		}

		@Override
		protected final void writeInternal(Void data) {
		AtomicFile file = getFile();
		FileOutputStream output = null;
		try {
		output = file.startWrite();
		write(output);
		file.finishWrite(output);
		} catch (IOException e) {
		file.failWrite(output);
		Slog.e(TAG, "Failed to write dynamic usage for secondary code files.", e);
		}
		}

		@VisibleForTesting
		void write(OutputStream output) throws IOException {
		// Make a deep copy to avoid holding the lock while writing to disk.
		Map<String, PackageDynamicCode> copiedMap;
		synchronized (mLock) {
		copiedMap = new HashMap<>(mPackageMap.size());
		for (Entry<String, PackageDynamicCode> entry : mPackageMap.entrySet()) {
		PackageDynamicCode copiedValue = new PackageDynamicCode(entry.getValue());
		copiedMap.put(entry.getKey(), copiedValue);
		}
		}

		write(output, copiedMap);
		}

		/**
		* Write the dynamic code loading data as a text file to {@code output}. The file format begins
		* with a line indicating the file type and version - {@link #FILE_VERSION_HEADER}.
		* <p>There is then one section for each owning package, introduced by a line beginning "P:".
		* This is followed by a line for each file owned by the package this is dynamically loaded,
		* containing the file type, user ID, loading package names and full path (with newlines and
		* backslashes escaped - see {@link #escape}).
		* <p>For example:
		* <pre>{@code
		* DCL1
		* P:first.owning.package
		* D:0:loading.package_1,loading.package_2:/path/to/file
		* D:10:loading.package_1:/another/file
		* P:second.owning.package
		* D:0:loading.package:/third/file
		* }</pre>
		*/
		private static void write(OutputStream output, Map<String, PackageDynamicCode> packageMap)
		throws IOException {
		PrintWriter writer = new FastPrintWriter(output);

		writer.println(FILE_VERSION_HEADER);
		for (Entry<String, PackageDynamicCode> packageEntry : packageMap.entrySet()) {
		writer.print(PACKAGE_PREFIX);
		writer.println(packageEntry.getKey());

		Map<String, DynamicCodeFile> mFileUsageMap = packageEntry.getValue().mFileUsageMap;
		for (Entry<String, DynamicCodeFile> fileEntry : mFileUsageMap.entrySet()) {
		String path = fileEntry.getKey();
		DynamicCodeFile dynamicCodeFile = fileEntry.getValue();

		writer.print(dynamicCodeFile.mFileType);
		writer.print(FIELD_SEPARATOR);
		writer.print(dynamicCodeFile.mUserId);
		writer.print(FIELD_SEPARATOR);

		String prefix = "";
		for (String packageName : dynamicCodeFile.mLoadingPackages) {
		writer.print(prefix);
		writer.print(packageName);
		prefix = PACKAGE_SEPARATOR;
		}

		writer.print(FIELD_SEPARATOR);
		writer.println(escape(path));
		}
		}

		writer.flush();
		if (writer.checkError()) {
		throw new IOException("Writer failed");
		}
		}

		/**
		* Read data from the persistent file. Replaces existing data completely if successful.
		*/
		void read() {
		super.read(null);
		}

		@Override
		protected final void readInternal(Void data) {
		AtomicFile file = getFile();

		FileInputStream stream = null;
		try {
		stream = file.openRead();
		read(stream);
		} catch (FileNotFoundException expected) {
		// The file may not be there. E.g. When we first take the OTA with this feature.
		} catch (IOException e) {
		Slog.w(TAG, "Failed to parse dynamic usage for secondary code files.", e);
		} finally {
		IoUtils.closeQuietly(stream);
		}
		}

		@VisibleForTesting
		void read(InputStream stream) throws IOException {
		Map<String, PackageDynamicCode> newPackageMap = new HashMap<>();
		read(stream, newPackageMap);
		synchronized (mLock) {
		mPackageMap = newPackageMap;
		}
		}

		private static void read(InputStream stream, Map<String, PackageDynamicCode> packageMap)
		throws IOException {
		BufferedReader reader = new BufferedReader(new InputStreamReader(stream));

		String versionLine = reader.readLine();
		if (!FILE_VERSION_HEADER.equals(versionLine)) {
		throw new IOException("Incorrect version line: " + versionLine);
		}

		String line = reader.readLine();
		if (line != null && !line.startsWith(PACKAGE_PREFIX)) {
		throw new IOException("Malformed line: " + line);
		}

		while (line != null) {
		String packageName = line.substring(PACKAGE_PREFIX.length());

		PackageDynamicCode packageInfo = new PackageDynamicCode();
		while (true) {
		line = reader.readLine();
		if (line == null \|\| line.startsWith(PACKAGE_PREFIX)) {
		break;
		}
		readFileInfo(line, packageInfo);
		}

		if (!packageInfo.mFileUsageMap.isEmpty()) {
		packageMap.put(packageName, packageInfo);
		}
		}
		}

		private static void readFileInfo(String line, PackageDynamicCode output) throws IOException {
		try {
		Matcher matcher = PACKAGE_LINE_PATTERN.matcher(line);
		if (!matcher.matches()) {
		throw new IOException("Malformed line: " + line);
		}

		char type = matcher.group(1).charAt(0);
		int user = Integer.parseInt(matcher.group(2));
		String[] packages = matcher.group(3).split(PACKAGE_SEPARATOR);
		String path = unescape(matcher.group(4));

		if (packages.length == 0) {
		throw new IOException("Malformed line: " + line);
		}
		if (type != FILE_TYPE_DEX) {
		throw new IOException("Unknown file type: " + line);
		}

		output.mFileUsageMap.put(path, new DynamicCodeFile(type, user, packages));
		} catch (RuntimeException e) {
		// Just in case we get NumberFormatException, or various
		// impossible out of bounds errors happen.
		throw new IOException("Unable to parse line: " + line, e);
		}
		}

		/**
		* Escape any newline and backslash characters in path. A newline in a path is legal if unusual,
		* and it would break our line-based file parsing.
		*/
		@VisibleForTesting
		static String escape(String path) {
		if (path.indexOf('\\') == -1 && path.indexOf('\n') == -1 && path.indexOf('\r') == -1) {
		return path;
		}

		StringBuilder result = new StringBuilder(path.length() + 10);
		for (int i = 0; i < path.length(); i++) {
		// Surrogates will never match the characters we care about, so it's ok to use chars
		// not code points here.
		char c = path.charAt(i);
		switch (c) {
		case '\\':
		result.append("\\\\");
		break;
		case '\n':
		result.append("\\n");
		break;
		case '\r':
		result.append("\\r");
		break;
		default:
		result.append(c);
		break;
		}
		}
		return result.toString();
		}

		/**
		* Reverse the effect of {@link #escape}.
		* @throws IOException if the input string is malformed
		*/
		@VisibleForTesting
		static String unescape(String escaped) throws IOException {
		// As we move through the input string, start is the position of the first character
		// after the previous escape sequence and finish is the position of the following backslash.
		int start = 0;
		int finish = escaped.indexOf('\\');
		if (finish == -1) {
		return escaped;
		}

		StringBuilder result = new StringBuilder(escaped.length());
		while (true) {
		if (finish >= escaped.length() - 1) {
		// Backslash mustn't be the last character
		throw new IOException("Unexpected \\ in: " + escaped);
		}
		result.append(escaped, start, finish);
		switch (escaped.charAt(finish + 1)) {
		case '\\':
		result.append('\\');
		break;
		case 'r':
		result.append('\r');
		break;
		case 'n':
		result.append('\n');
		break;
		default:
		throw new IOException("Bad escape in: " + escaped);
		}

		start = finish + 2;
		finish = escaped.indexOf('\\', start);
		if (finish == -1) {
		result.append(escaped, start, escaped.length());
		break;
		}
		}
		return result.toString();
		}

		/**
		* Represents the dynamic code usage of a single package.
		*/
		static class PackageDynamicCode {
		/**
		* Map from secondary code file path to information about which packages dynamically load
		* that file.
		*/
		final Map<String, DynamicCodeFile> mFileUsageMap;

		private PackageDynamicCode() {
		mFileUsageMap = new HashMap<>();
		}

		private PackageDynamicCode(PackageDynamicCode original) {
		mFileUsageMap = new HashMap<>(original.mFileUsageMap.size());
		for (Entry<String, DynamicCodeFile> entry : original.mFileUsageMap.entrySet()) {
		DynamicCodeFile newValue = new DynamicCodeFile(entry.getValue());
		mFileUsageMap.put(entry.getKey(), newValue);
		}
		}

		private boolean add(String path, char fileType, int userId, String loadingPackage) {
		DynamicCodeFile fileInfo = mFileUsageMap.get(path);
		if (fileInfo == null) {
		fileInfo = new DynamicCodeFile(fileType, userId, loadingPackage);
		mFileUsageMap.put(path, fileInfo);
		return true;
		} else {
		if (fileInfo.mUserId != userId) {
		// This should be impossible: private app files are always user-specific and
		// can't be accessed from different users.
		throw new IllegalArgumentException("Cannot change userId for '" + path
		+ "' from " + fileInfo.mUserId + " to " + userId);
		}
		// Changing file type (i.e. loading the same file in different ways is possible if
		// unlikely. We allow it but ignore it.
		return fileInfo.mLoadingPackages.add(loadingPackage);
		}
		}

		private boolean removeUser(int userId) {
		boolean updated = false;
		Iterator<DynamicCodeFile> it = mFileUsageMap.values().iterator();
		while (it.hasNext()) {
		DynamicCodeFile fileInfo = it.next();
		if (fileInfo.mUserId == userId) {
		it.remove();
		updated = true;
		}
		}
		return updated;
		}

		private boolean removeFile(String filePath, int userId) {
		DynamicCodeFile fileInfo = mFileUsageMap.get(filePath);
		if (fileInfo == null \|\| fileInfo.mUserId != userId) {
		return false;
		} else {
		mFileUsageMap.remove(filePath);
		return true;
		}
		}

		private void syncData(Map<String, Set<Integer>> packageToUsersMap,
		Set<Integer> owningPackageUsers) {
		Iterator<DynamicCodeFile> fileIt = mFileUsageMap.values().iterator();
		while (fileIt.hasNext()) {
		DynamicCodeFile fileInfo = fileIt.next();
		int fileUserId = fileInfo.mUserId;
		if (!owningPackageUsers.contains(fileUserId)) {
		fileIt.remove();
		} else {
		// Also remove information about any loading packages that are no longer
		// installed for this user.
		Iterator<String> loaderIt = fileInfo.mLoadingPackages.iterator();
		while (loaderIt.hasNext()) {
		String loader = loaderIt.next();
		Set<Integer> loadingPackageUsers = packageToUsersMap.get(loader);
		if (loadingPackageUsers == null
		\|\| !loadingPackageUsers.contains(fileUserId)) {
		loaderIt.remove();
		}
		}
		if (fileInfo.mLoadingPackages.isEmpty()) {
		fileIt.remove();
		}
		}
		}
		}
		}

		/**
		* Represents a single dynamic code file loaded by one or more packages. Note that it is
		* possible for one app to dynamically load code from a different app's home dir, if the
		* owning app:
		* <ul>
		* <li>Targets API 27 or lower and has shared its home dir.
		* <li>Is a system app.
		* <li>Has a shared UID with the loading app.
		* </ul>
		*/
		static class DynamicCodeFile {
		final char mFileType;
		final int mUserId;
		final Set<String> mLoadingPackages;

		private DynamicCodeFile(char type, int user, String... packages) {
		mFileType = type;
		mUserId = user;
		mLoadingPackages = new HashSet<>(Arrays.asList(packages));
		}

		private DynamicCodeFile(DynamicCodeFile original) {
		mFileType = original.mFileType;
		mUserId = original.mUserId;
		mLoadingPackages = new HashSet<>(original.mLoadingPackages);
		}
		}
		}