Add utils for converting Maps and ParcelUuid to/from PersistableBundle (296c895e) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/vcn/util/PersistableBundleUtils.java

+183 −3

Original line number	Diff line number	Diff line
		@@ -17,15 +17,31 @@
		package com.android.server.vcn.util;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.os.ParcelUuid;
		import android.os.PersistableBundle;

		import java.io.File;
		import java.io.FileInputStream;
		import java.io.FileOutputStream;
		import java.io.IOException;
		import java.util.ArrayList;
		import java.util.LinkedHashMap;
		import java.util.List;
		import java.util.Map;
		import java.util.Map.Entry;
		import java.util.Objects;
		import java.util.concurrent.locks.ReadWriteLock;
		import java.util.concurrent.locks.ReentrantReadWriteLock;

		/** @hide */
		public class PersistableBundleUtils {
		private static final String LIST_KEY_FORMAT = "LIST_ITEM_%d";
		private static final String LIST_LENGTH_KEY = "LIST_LENGTH";
		private static final String COLLECTION_SIZE_KEY = "COLLECTION_LENGTH";
		private static final String MAP_KEY_FORMAT = "MAP_KEY_%d";
		private static final String MAP_VALUE_FORMAT = "MAP_VALUE_%d";

		private static final String PARCEL_UUID_KEY = "PARCEL_UUID";

		/**
		* Functional interface to convert an object of the specified type to a PersistableBundle.
		@@ -56,6 +72,33 @@ public class PersistableBundleUtils {
		T fromPersistableBundle(PersistableBundle in);
		}

		/**
		* Converts a ParcelUuid to a PersistableBundle.
		*
		* <p>To avoid key collisions, NO additional key/value pairs should be added to the returned
		* PersistableBundle object.
		*
		* @param uuid a ParcelUuid instance to persist
		* @return the PersistableBundle instance
		*/
		public static PersistableBundle fromParcelUuid(ParcelUuid uuid) {
		final PersistableBundle result = new PersistableBundle();

		result.putString(PARCEL_UUID_KEY, uuid.toString());

		return result;
		}

		/**
		* Converts from a PersistableBundle to a ParcelUuid.
		*
		* @param bundle the PersistableBundle containing the ParcelUuid
		* @return the ParcelUuid instance
		*/
		public static ParcelUuid toParcelUuid(PersistableBundle bundle) {
		return ParcelUuid.fromString(bundle.getString(PARCEL_UUID_KEY));
		}

		/**
		* Converts from a list of Persistable objects to a single PersistableBundle.
		*
		@@ -72,7 +115,7 @@ public class PersistableBundleUtils {
		@NonNull List<T> in, @NonNull Serializer<T> serializer) {
		final PersistableBundle result = new PersistableBundle();

		result.putInt(LIST_LENGTH_KEY, in.size());
		result.putInt(COLLECTION_SIZE_KEY, in.size());
		for (int i = 0; i < in.size(); i++) {
		final String key = String.format(LIST_KEY_FORMAT, i);
		result.putPersistableBundle(key, serializer.toPersistableBundle(in.get(i)));
		@@ -91,7 +134,7 @@ public class PersistableBundleUtils {
		@NonNull
		public static <T> List<T> toList(
		@NonNull PersistableBundle in, @NonNull Deserializer<T> deserializer) {
		final int listLength = in.getInt(LIST_LENGTH_KEY);
		final int listLength = in.getInt(COLLECTION_SIZE_KEY);
		final ArrayList<T> result = new ArrayList<>(listLength);

		for (int i = 0; i < listLength; i++) {
		@@ -102,4 +145,141 @@ public class PersistableBundleUtils {
		}
		return result;
		}

		/**
		* Converts from a Map of Persistable objects to a single PersistableBundle.
		*
		* <p>To avoid key collisions, NO additional key/value pairs should be added to the returned
		* PersistableBundle object.
		*
		* @param <K> the type of the map-key to convert to the PersistableBundle
		* @param <V> the type of the map-value to convert to the PersistableBundle
		* @param in the Map of objects implementing the {@link Persistable} interface
		* @param keySerializer an implementation of the {@link Serializer} functional interface that
		* converts a map-key of type T to a PersistableBundle
		* @param valueSerializer an implementation of the {@link Serializer} functional interface that
		* converts a map-value of type E to a PersistableBundle
		*/
		@NonNull
		public static <K, V> PersistableBundle fromMap(
		@NonNull Map<K, V> in,
		@NonNull Serializer<K> keySerializer,
		@NonNull Serializer<V> valueSerializer) {
		final PersistableBundle result = new PersistableBundle();

		result.putInt(COLLECTION_SIZE_KEY, in.size());
		int i = 0;
		for (Entry<K, V> entry : in.entrySet()) {
		final String keyKey = String.format(MAP_KEY_FORMAT, i);
		final String valueKey = String.format(MAP_VALUE_FORMAT, i);
		result.putPersistableBundle(keyKey, keySerializer.toPersistableBundle(entry.getKey()));
		result.putPersistableBundle(
		valueKey, valueSerializer.toPersistableBundle(entry.getValue()));

		i++;
		}

		return result;
		}

		/**
		* Converts from a PersistableBundle to a Map of objects.
		*
		* <p>In an attempt to preserve ordering, the returned map will be a LinkedHashMap. However, the
		* guarantees on the ordering can only ever be as strong as the map that was serialized in
		* {@link fromMap()}. If the initial map that was serialized had no ordering guarantees, the
		* deserialized map similarly may be of a non-deterministic order.
		*
		* @param <K> the type of the map-key to convert from a PersistableBundle
		* @param <V> the type of the map-value to convert from a PersistableBundle
		* @param in the PersistableBundle containing the persisted Map
		* @param keyDeserializer an implementation of the {@link Deserializer} functional interface
		* that builds the relevant type of map-key.
		* @param valueDeserializer an implementation of the {@link Deserializer} functional interface
		* that builds the relevant type of map-value.
		* @return An instance of the parsed map as a LinkedHashMap (in an attempt to preserve
		* ordering).
		*/
		@NonNull
		public static <K, V> LinkedHashMap<K, V> toMap(
		@NonNull PersistableBundle in,
		@NonNull Deserializer<K> keyDeserializer,
		@NonNull Deserializer<V> valueDeserializer) {
		final int mapSize = in.getInt(COLLECTION_SIZE_KEY);
		final LinkedHashMap<K, V> result = new LinkedHashMap<>(mapSize);

		for (int i = 0; i < mapSize; i++) {
		final String keyKey = String.format(MAP_KEY_FORMAT, i);
		final String valueKey = String.format(MAP_VALUE_FORMAT, i);
		final PersistableBundle keyBundle = in.getPersistableBundle(keyKey);
		final PersistableBundle valueBundle = in.getPersistableBundle(valueKey);

		final K key = keyDeserializer.fromPersistableBundle(keyBundle);
		final V value = valueDeserializer.fromPersistableBundle(valueBundle);
		result.put(key, value);
		}
		return result;
		}

		/**
		* Ensures safe reading and writing of {@link PersistableBundle}s to and from disk.
		*
		* <p>This class will enforce exclusion between reads and writes using the standard semantics of
		* a ReadWriteLock. Specifically, concurrent readers ARE allowed, but reads/writes from/to the
		* file are mutually exclusive. In other words, for an unbounded number n, the acceptable states
		* are n readers, OR 1 writer (but not both).
		*/
		public static class LockingReadWriteHelper {
		private final ReadWriteLock mDiskLock = new ReentrantReadWriteLock();
		private final String mPath;

		public LockingReadWriteHelper(@NonNull String path) {
		mPath = Objects.requireNonNull(path, "fileName was null");
		}

		/**
		* Reads the {@link PersistableBundle} from the disk.
		*
		* @return the PersistableBundle, if the file existed, or null otherwise
		*/
		@Nullable
		public PersistableBundle readFromDisk() throws IOException {
		try {
		mDiskLock.readLock().lock();
		final File file = new File(mPath);
		if (!file.exists()) {
		return null;
		}

		try (FileInputStream fis = new FileInputStream(file)) {
		return PersistableBundle.readFromStream(fis);
		}
		} finally {
		mDiskLock.readLock().unlock();
		}
		}

		/**
		* Writes a {@link PersistableBundle} to disk.
		*
		* @param bundle the {@link PersistableBundle} to write to disk
		*/
		public void writeToDisk(@NonNull PersistableBundle bundle) throws IOException {
		Objects.requireNonNull(bundle, "bundle was null");

		try {
		mDiskLock.writeLock().lock();
		final File file = new File(mPath);
		if (!file.exists()) {
		file.getParentFile().mkdirs();
		}

		try (FileOutputStream fos = new FileOutputStream(file)) {
		bundle.writeToStream(fos);
		}
		} finally {
		mDiskLock.writeLock().unlock();
		}
		}
		}
		}

tests/vcn/java/com/android/server/vcn/util/PersistableBundleUtilsTest.java

+62 −1

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@ import org.junit.runner.RunWith;

		import java.util.ArrayList;
		import java.util.Arrays;
		import java.util.LinkedHashMap;
		import java.util.List;
		import java.util.Objects;

		@@ -40,6 +41,43 @@ public class PersistableBundleUtilsTest {

		private static final int NUM_COLLECTION_ENTRIES = 10;

		private static class TestKey {
		private static final String TEST_INTEGER_KEY =
		"mTestInteger"; // Purposely colliding with keys of test class to ensure namespacing
		private final int mTestInteger;

		TestKey(int testInteger) {
		mTestInteger = testInteger;
		}

		TestKey(PersistableBundle in) {
		mTestInteger = in.getInt(TEST_INTEGER_KEY);
		}

		public PersistableBundle toPersistableBundle() {
		final PersistableBundle result = new PersistableBundle();

		result.putInt(TEST_INTEGER_KEY, mTestInteger);

		return result;
		}

		@Override
		public int hashCode() {
		return Objects.hash(mTestInteger);
		}

		@Override
		public boolean equals(Object o) {
		if (!(o instanceof TestKey)) {
		return false;
		}

		final TestKey other = (TestKey) o;
		return mTestInteger == other.mTestInteger;
		}
		}

		private static class TestClass {
		private static final String TEST_INTEGER_KEY = "mTestInteger";
		private final int mTestInteger;
		@@ -113,7 +151,7 @@ public class PersistableBundleUtilsTest {
		}

		@Test
		public void testConversionLossless() throws Exception {
		public void testListConversionLossless() throws Exception {
		final List<TestClass> sourceList = new ArrayList<>();
		for (int i = 0; i < NUM_COLLECTION_ENTRIES; i++) {
		final PersistableBundle innerBundle = new PersistableBundle();
		@@ -128,4 +166,27 @@ public class PersistableBundleUtilsTest {

		assertEquals(sourceList, resultList);
		}

		@Test
		public void testMapConversionLossless() throws Exception {
		final LinkedHashMap<TestKey, TestClass> sourceMap = new LinkedHashMap<>();
		for (int i = 0; i < NUM_COLLECTION_ENTRIES; i++) {
		final TestKey key = new TestKey(i * i);

		final PersistableBundle innerBundle = new PersistableBundle();
		innerBundle.putInt(TEST_KEY, i);
		final TestClass value =
		new TestClass(i, TEST_INT_ARRAY, TEST_STRING_PREFIX + i, innerBundle);

		sourceMap.put(key, value);
		}

		final PersistableBundle bundled =
		PersistableBundleUtils.fromMap(
		sourceMap, TestKey::toPersistableBundle, TestClass::toPersistableBundle);
		final LinkedHashMap<TestKey, TestClass> resultList =
		PersistableBundleUtils.toMap(bundled, TestKey::new, TestClass::new);

		assertEquals(sourceMap, resultList);
		}
		}