Merge changes from topics "PersistableBundleUtils", "bytearray-utils", "integer-utils" am: e9226f999f am: 089a20034d am: 984f6a74ad

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1495099

Change-Id: I526b6098f46ee00ba17b2f3f5c0e679dc57190b5
diff --git a/Android.bp b/Android.bp
index eb1718e..570040f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -744,6 +744,7 @@
         "core/java/com/android/internal/util/IState.java",
         "core/java/com/android/internal/util/State.java",
         "core/java/com/android/internal/util/StateMachine.java",
+        "services/core/java/com/android/server/vcn/util/PersistableBundleUtils.java",
         "telephony/java/android/telephony/Annotation.java",
     ],
 }
diff --git a/services/core/java/com/android/server/vcn/util/PersistableBundleUtils.java b/services/core/java/com/android/server/vcn/util/PersistableBundleUtils.java
new file mode 100644
index 0000000..5c1b5ff
--- /dev/null
+++ b/services/core/java/com/android/server/vcn/util/PersistableBundleUtils.java
@@ -0,0 +1,341 @@
+/*
+ * Copyright (C) 2020 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.vcn.util;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.os.ParcelUuid;
+import android.os.PersistableBundle;
+
+import com.android.internal.util.HexDump;
+
+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 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";
+    private static final String BYTE_ARRAY_KEY = "BYTE_ARRAY_KEY";
+    private static final String INTEGER_KEY = "INTEGER_KEY";
+
+    /**
+     * Functional interface to convert an object of the specified type to a PersistableBundle.
+     *
+     * @param <T> the type of the source object
+     */
+    public interface Serializer<T> {
+        /**
+         * Converts this object to a PersistableBundle.
+         *
+         * @return the PersistableBundle representation of this object
+         */
+        PersistableBundle toPersistableBundle(T obj);
+    }
+
+    /**
+     * Functional interface used to create an object of the specified type from a PersistableBundle.
+     *
+     * @param <T> the type of the resultant object
+     */
+    public interface Deserializer<T> {
+        /**
+         * Creates an instance of specified type from a PersistableBundle representation.
+         *
+         * @param in the PersistableBundle representation
+         * @return an instance of the specified type
+         */
+        T fromPersistableBundle(PersistableBundle in);
+    }
+
+    /** Serializer to convert an integer to a PersistableBundle. */
+    public static final Serializer<Integer> INTEGER_SERIALIZER =
+            (i) -> {
+                final PersistableBundle result = new PersistableBundle();
+                result.putInt(INTEGER_KEY, i);
+                return result;
+            };
+
+    /** Deserializer to convert a PersistableBundle to an integer. */
+    public static final Deserializer<Integer> INTEGER_DESERIALIZER =
+            (bundle) -> {
+                Objects.requireNonNull(bundle, "PersistableBundle is null");
+                return bundle.getInt(INTEGER_KEY);
+            };
+
+    /**
+     * 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.
+     *
+     * <p>To avoid key collisions, NO additional key/value pairs should be added to the returned
+     * PersistableBundle object.
+     *
+     * @param <T> the type of the objects to convert to the PersistableBundle
+     * @param in the list of objects to be serialized into a PersistableBundle
+     * @param serializer an implementation of the {@link Serializer} functional interface that
+     *     converts an object of type T to a PersistableBundle
+     */
+    @NonNull
+    public static <T> PersistableBundle fromList(
+            @NonNull List<T> in, @NonNull Serializer<T> serializer) {
+        final PersistableBundle result = new PersistableBundle();
+
+        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)));
+        }
+        return result;
+    }
+
+    /**
+     * Converts from a PersistableBundle to a list of objects.
+     *
+     * @param <T> the type of the objects to convert from a PersistableBundle
+     * @param in the PersistableBundle containing the persisted list
+     * @param deserializer an implementation of the {@link Deserializer} functional interface that
+     *     builds the relevant type of objects.
+     */
+    @NonNull
+    public static <T> List<T> toList(
+            @NonNull PersistableBundle in, @NonNull Deserializer<T> deserializer) {
+        final int listLength = in.getInt(COLLECTION_SIZE_KEY);
+        final ArrayList<T> result = new ArrayList<>(listLength);
+
+        for (int i = 0; i < listLength; i++) {
+            final String key = String.format(LIST_KEY_FORMAT, i);
+            final PersistableBundle item = in.getPersistableBundle(key);
+
+            result.add(deserializer.fromPersistableBundle(item));
+        }
+        return result;
+    }
+
+    // TODO: b/170513329 Delete #fromByteArray and #toByteArray once BaseBundle#putByteArray and
+    // BaseBundle#getByteArray are exposed.
+
+    /**
+     * Converts a byte array to a PersistableBundle.
+     *
+     * <p>To avoid key collisions, NO additional key/value pairs should be added to the returned
+     * PersistableBundle object.
+     *
+     * @param array a byte array instance to persist
+     * @return the PersistableBundle instance
+     */
+    public static PersistableBundle fromByteArray(byte[] array) {
+        final PersistableBundle result = new PersistableBundle();
+
+        result.putString(BYTE_ARRAY_KEY, HexDump.toHexString(array));
+
+        return result;
+    }
+
+    /**
+     * Converts from a PersistableBundle to a byte array.
+     *
+     * @param bundle the PersistableBundle containing the byte array
+     * @return the byte array instance
+     */
+    public static byte[] toByteArray(PersistableBundle bundle) {
+        Objects.requireNonNull(bundle, "PersistableBundle is null");
+
+        String hex = bundle.getString(BYTE_ARRAY_KEY);
+        if (hex == null || hex.length() % 2 != 0) {
+            throw new IllegalArgumentException("PersistableBundle contains invalid byte array");
+        }
+
+        return HexDump.hexStringToByteArray(hex);
+    }
+
+    /**
+     * 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();
+            }
+        }
+    }
+}
diff --git a/tests/vcn/java/com/android/server/vcn/util/PersistableBundleUtilsTest.java b/tests/vcn/java/com/android/server/vcn/util/PersistableBundleUtilsTest.java
new file mode 100644
index 0000000..a44a734
--- /dev/null
+++ b/tests/vcn/java/com/android/server/vcn/util/PersistableBundleUtilsTest.java
@@ -0,0 +1,214 @@
+/*
+ * Copyright (C) 2020 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.vcn.util;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+import android.os.PersistableBundle;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+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;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class PersistableBundleUtilsTest {
+    private static final String TEST_KEY = "testKey";
+    private static final String TEST_STRING_PREFIX = "testString";
+    private static final int[] TEST_INT_ARRAY = new int[] {0, 1, 2, 3, 4};
+
+    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;
+
+        private static final String TEST_INT_ARRAY_KEY = "mTestIntArray";
+        private final int[] mTestIntArray;
+
+        private static final String TEST_STRING_KEY = "mTestString";
+        private final String mTestString;
+
+        private static final String TEST_PERSISTABLE_BUNDLE_KEY = "mTestPersistableBundle";
+        private final PersistableBundle mTestPersistableBundle;
+
+        TestClass(
+                int testInteger,
+                int[] testIntArray,
+                String testString,
+                PersistableBundle testPersistableBundle) {
+            mTestInteger = testInteger;
+            mTestIntArray = testIntArray;
+            mTestString = testString;
+            mTestPersistableBundle = testPersistableBundle;
+        }
+
+        TestClass(PersistableBundle in) {
+            mTestInteger = in.getInt(TEST_INTEGER_KEY);
+            mTestIntArray = in.getIntArray(TEST_INT_ARRAY_KEY);
+            mTestString = in.getString(TEST_STRING_KEY);
+            mTestPersistableBundle = in.getPersistableBundle(TEST_PERSISTABLE_BUNDLE_KEY);
+        }
+
+        public PersistableBundle toPersistableBundle() {
+            final PersistableBundle result = new PersistableBundle();
+
+            result.putInt(TEST_INTEGER_KEY, mTestInteger);
+            result.putIntArray(TEST_INT_ARRAY_KEY, mTestIntArray);
+            result.putString(TEST_STRING_KEY, mTestString);
+            result.putPersistableBundle(TEST_PERSISTABLE_BUNDLE_KEY, mTestPersistableBundle);
+
+            return result;
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(
+                    mTestInteger,
+                    Arrays.hashCode(mTestIntArray),
+                    mTestString,
+                    mTestPersistableBundle);
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (!(o instanceof TestClass)) {
+                return false;
+            }
+
+            final TestClass other = (TestClass) o;
+
+            // TODO: Add a proper equals() to PersistableBundle. But in the meantime, force
+            // TODO: unparcelling in order to allow test comparison.
+            if (mTestPersistableBundle.size() != other.mTestPersistableBundle.size()) {
+                return false;
+            }
+
+            return mTestInteger == other.mTestInteger
+                    && Arrays.equals(mTestIntArray, other.mTestIntArray)
+                    && mTestString.equals(other.mTestString)
+                    && mTestPersistableBundle.kindofEquals(other.mTestPersistableBundle);
+        }
+    }
+
+    @Test
+    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();
+            innerBundle.putInt(TEST_KEY, i);
+
+            sourceList.add(new TestClass(i, TEST_INT_ARRAY, TEST_STRING_PREFIX + i, innerBundle));
+        }
+
+        final PersistableBundle bundled =
+                PersistableBundleUtils.fromList(sourceList, TestClass::toPersistableBundle);
+        final List<TestClass> resultList = PersistableBundleUtils.toList(bundled, TestClass::new);
+
+        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);
+    }
+
+    @Test
+    public void testByteArrayConversionLossless() {
+        final byte[] byteArray = "testByteArrayConversionLossless".getBytes();
+
+        PersistableBundle bundle = PersistableBundleUtils.fromByteArray(byteArray);
+        byte[] result = PersistableBundleUtils.toByteArray(bundle);
+
+        assertArrayEquals(byteArray, result);
+    }
+
+    @Test
+    public void testIntegerConversionLossless() throws Exception {
+        final int testInt = 1;
+        final PersistableBundle integerBundle =
+                PersistableBundleUtils.INTEGER_SERIALIZER.toPersistableBundle(testInt);
+        final int result =
+                PersistableBundleUtils.INTEGER_DESERIALIZER.fromPersistableBundle(integerBundle);
+
+        assertEquals(testInt, result);
+    }
+}