Merge "[1/n] Implement SynchedDeviceConfig utility class" into udc-qpr-dev

2 files changed, 384 insertions, 0 deletions

diff --git a/services/core/java/com/android/server/wm/SynchedDeviceConfig.java b/services/core/java/com/android/server/wm/SynchedDeviceConfig.java
new file mode 100644
index 000000000000..c2e819e4c60b
--- /dev/null
+++ b/services/core/java/com/android/server/wm/SynchedDeviceConfig.java
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2023 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.wm;
+
+import android.annotation.NonNull;
+import android.provider.DeviceConfig;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Executor;
+
+/**
+ * Utility class that caches {@link DeviceConfig} flags and listens to updates by implementing
+ * {@link DeviceConfig.OnPropertiesChangedListener}.
+ */
+final class SynchedDeviceConfig implements DeviceConfig.OnPropertiesChangedListener {
+
+    private final String mNamespace;
+    private final Executor mExecutor;
+
+    private final Map<String, SynchedDeviceConfigEntry> mDeviceConfigEntries;
+
+    /**
+     * @param namespace The namespace for the {@link DeviceConfig}
+     * @param executor  The {@link Executor} implementation to use when receiving updates
+     * @return the Builder implementation for the SynchedDeviceConfig
+     */
+    @NonNull
+    static SynchedDeviceConfigBuilder builder(@NonNull String namespace,
+            @NonNull Executor executor) {
+        return new SynchedDeviceConfigBuilder(namespace, executor);
+    }
+
+    private SynchedDeviceConfig(@NonNull String namespace, @NonNull Executor executor,
+            @NonNull Map<String, SynchedDeviceConfigEntry> deviceConfigEntries) {
+        mNamespace = namespace;
+        mExecutor = executor;
+        mDeviceConfigEntries = deviceConfigEntries;
+    }
+
+    @Override
+    public void onPropertiesChanged(@NonNull final DeviceConfig.Properties properties) {
+        for (SynchedDeviceConfigEntry entry : mDeviceConfigEntries.values()) {
+            if (properties.getKeyset().contains(entry.mFlagKey)) {
+                entry.updateValue(properties.getBoolean(entry.mFlagKey, entry.mDefaultValue));
+            }
+        }
+    }
+
+    /**
+     * Builds the {@link SynchedDeviceConfig} and start listening to the {@link DeviceConfig}
+     * updates.
+     *
+     * @return The {@link SynchedDeviceConfig}
+     */
+    @NonNull
+    private SynchedDeviceConfig start() {
+        DeviceConfig.addOnPropertiesChangedListener(mNamespace,
+                mExecutor, /* onPropertiesChangedListener */ this);
+        return this;
+    }
+
+    /**
+     * Requests a {@link DeviceConfig} update for all the flags
+     */
+    @NonNull
+    private SynchedDeviceConfig updateFlags() {
+        mDeviceConfigEntries.forEach((key, entry) -> entry.updateValue(
+                isDeviceConfigFlagEnabled(key, entry.mDefaultValue)));
+        return this;
+    }
+
+    /**
+     * Returns values of the {@code key} flag with the following criteria:
+     *
+     * <ul>
+     *     <li>{@code false} if the build time flag is disabled.
+     *     <li>{@code defaultValue} if the build time flag is enabled and no {@link DeviceConfig}
+     *          updates happened
+     *     <li>Last value from {@link DeviceConfig} in case of updates.
+     * </ul>
+     *
+     * @throws IllegalArgumentException {@code key} isn't recognised.
+     */
+    boolean getFlagValue(@NonNull String key) {
+        return findEntry(key).map(SynchedDeviceConfigEntry::getValue)
+                .orElseThrow(() -> new IllegalArgumentException("Unexpected flag name: " + key));
+    }
+
+    /**
+     * @return {@code true} if the flag for the given {@code key} was enabled at build time.
+     */
+    boolean isBuildTimeFlagEnabled(@NonNull String key) {
+        return findEntry(key).map(SynchedDeviceConfigEntry::isBuildTimeFlagEnabled)
+                .orElseThrow(() -> new IllegalArgumentException("Unexpected flag name: " + key));
+    }
+
+    private boolean isDeviceConfigFlagEnabled(@NonNull String key, boolean defaultValue) {
+        return DeviceConfig.getBoolean(mNamespace, key, defaultValue);
+    }
+
+    @NonNull
+    private Optional<SynchedDeviceConfigEntry> findEntry(@NonNull String key) {
+        return Optional.ofNullable(mDeviceConfigEntries.get(key));
+    }
+
+    static class SynchedDeviceConfigBuilder {
+
+        private final String mNamespace;
+        private final Executor mExecutor;
+
+        private final Map<String, SynchedDeviceConfigEntry> mDeviceConfigEntries =
+                new ConcurrentHashMap<>();
+
+        private SynchedDeviceConfigBuilder(@NonNull String namespace, @NonNull Executor executor) {
+            mNamespace = namespace;
+            mExecutor = executor;
+        }
+
+        @NonNull
+        SynchedDeviceConfigBuilder addDeviceConfigEntry(@NonNull String key,
+                boolean defaultValue, boolean enabled) {
+            if (mDeviceConfigEntries.containsKey(key)) {
+                throw new AssertionError("Key already present: " + key);
+            }
+            mDeviceConfigEntries.put(key,
+                    new SynchedDeviceConfigEntry(key, defaultValue, enabled));
+            return this;
+        }
+
+        @NonNull
+        SynchedDeviceConfig build() {
+            return new SynchedDeviceConfig(mNamespace, mExecutor,
+                    mDeviceConfigEntries).updateFlags().start();
+        }
+    }
+
+    /**
+     * Contains all the information related to an entry to be managed by DeviceConfig
+     */
+    private static class SynchedDeviceConfigEntry {
+
+        // The key of the specific configuration flag
+        private final String mFlagKey;
+
+        // The value of the flag at build time.
+        private final boolean mBuildTimeFlagEnabled;
+
+        // The initial value of the flag when mBuildTimeFlagEnabled is true.
+        private final boolean mDefaultValue;
+
+        // The current value of the flag when mBuildTimeFlagEnabled is true.
+        private volatile boolean mOverrideValue;
+
+        private SynchedDeviceConfigEntry(@NonNull String flagKey, boolean defaultValue,
+                boolean enabled) {
+            mFlagKey = flagKey;
+            mOverrideValue = mDefaultValue = defaultValue;
+            mBuildTimeFlagEnabled = enabled;
+        }
+
+        @NonNull
+        private void updateValue(boolean newValue) {
+            mOverrideValue = newValue;
+        }
+
+        private boolean getValue() {
+            return mBuildTimeFlagEnabled && mOverrideValue;
+        }
+
+        private boolean isBuildTimeFlagEnabled() {
+            return mBuildTimeFlagEnabled;
+        }
+    }
+}
diff --git a/services/tests/wmtests/src/com/android/server/wm/SynchedDeviceConfigTests.java b/services/tests/wmtests/src/com/android/server/wm/SynchedDeviceConfigTests.java
new file mode 100644
index 000000000000..ecab62f72f69
--- /dev/null
+++ b/services/tests/wmtests/src/com/android/server/wm/SynchedDeviceConfigTests.java
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2023 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.wm;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.junit.Assert.assertEquals;
+
+import android.app.ActivityThread;
+import android.platform.test.annotations.Presubmit;
+import android.provider.DeviceConfig;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.modules.utils.testing.TestableDeviceConfig;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.util.Objects;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Test class for {@link SynchedDeviceConfig}.
+ *
+ * atest WmTests:SynchedDeviceConfigTests
+ */
+@SmallTest
+@Presubmit
+public class SynchedDeviceConfigTests {
+
+    private static final long WAIT_FOR_PROPERTY_CHANGE_TIMEOUT_MILLIS = 2000; // 2 sec
+    private static final String NAMESPACE_FOR_TEST = "TestingNameSpace";
+
+    private SynchedDeviceConfig mDeviceConfig;
+
+    private Executor mExecutor;
+
+    @Rule
+    public final TestableDeviceConfig.TestableDeviceConfigRule
+            mDeviceConfigRule = new TestableDeviceConfig.TestableDeviceConfigRule();
+
+    @Before
+    public void setUp() {
+        mExecutor = Objects.requireNonNull(ActivityThread.currentApplication()).getMainExecutor();
+        mDeviceConfig = SynchedDeviceConfig
+                .builder(/* nameSpace */ NAMESPACE_FOR_TEST, /* executor */ mExecutor)
+                .addDeviceConfigEntry(/* key */ "key1", /* default */ true, /* enabled */ true)
+                .addDeviceConfigEntry(/* key */ "key2", /* default */ false, /* enabled */ true)
+                .addDeviceConfigEntry(/* key */ "key3",  /* default */ true, /* enabled */ false)
+                .addDeviceConfigEntry(/* key */ "key4",  /* default */ false, /* enabled */ false)
+                .addDeviceConfigEntry(/* key */ "key5",  /* default */ true, /* enabled */ false)
+                .addDeviceConfigEntry(/* key */ "key6",  /* default */ false, /* enabled */ false)
+                .build();
+    }
+
+    @After
+    public void tearDown() {
+        DeviceConfig.removeOnPropertiesChangedListener(mDeviceConfig);
+    }
+
+    @Test
+    public void testWhenStarted_initialValuesAreDefaultOrFalseIfDisabled() {
+        assertFlagValue(/* key */ "key1", /* expected */ true); // enabled
+        assertFlagValue(/* key */ "key2", /* expected */ false); // enabled
+        assertFlagValue(/* key */ "key3", /* expected */ false); // disabled
+        assertFlagValue(/* key */ "key4", /* expected */ false); // disabled
+        assertFlagValue(/* key */ "key5", /* expected */ false); // disabled
+        assertFlagValue(/* key */ "key6", /* expected */ false); // disabled
+    }
+
+    @Test
+    public void testIsEnabled() {
+        assertFlagEnabled(/* key */ "key1", /* expected */ true);
+        assertFlagEnabled(/* key */ "key2", /* expected */ true);
+        assertFlagEnabled(/* key */ "key3", /* expected */ false);
+        assertFlagEnabled(/* key */ "key4", /* expected */ false);
+        assertFlagEnabled(/* key */ "key5", /* expected */ false);
+        assertFlagEnabled(/* key */ "key6", /* expected */ false);
+    }
+
+    @Test
+    public void testWhenUpdated_onlyEnabledChanges() {
+        final CountDownLatch countDownLatch = new CountDownLatch(4);
+        final DeviceConfig.OnPropertiesChangedListener countDownLatchListener =
+                properties -> countDownLatch.countDown();
+        DeviceConfig.addOnPropertiesChangedListener(NAMESPACE_FOR_TEST, mExecutor,
+                countDownLatchListener);
+
+        try {
+            // We update all the keys
+            updateProperty(/* key */ "key1", /* value */ false);
+            updateProperty(/* key */ "key2", /* value */ true);
+            updateProperty(/* key */ "key3", /* value */ false);
+            updateProperty(/* key */ "key4", /* value */ true);
+
+            assertThat(countDownLatch.await(
+                    WAIT_FOR_PROPERTY_CHANGE_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)).isTrue();
+
+            // We update all the flags but only the enabled ones change
+            assertFlagValue(/* key */ "key1", /* expected */ false); // changes
+            assertFlagValue(/* key */ "key2", /* expected */ true); // changes
+            assertFlagValue(/* key */ "key3", /* expected */ false); // disabled
+            assertFlagValue(/* key */ "key4", /* expected */ false); // disabled
+        } catch (InterruptedException e) {
+            Assert.fail(e.getMessage());
+        } finally {
+            DeviceConfig.removeOnPropertiesChangedListener(countDownLatchListener);
+        }
+    }
+
+    @Test
+    public void testWhenEnabled_updatesAreUsed() {
+        final CountDownLatch countDownLatchBefore = new CountDownLatch(2);
+        final CountDownLatch countDownLatchAfter = new CountDownLatch(2);
+        final DeviceConfig.OnPropertiesChangedListener countDownLatchBeforeListener =
+                properties -> countDownLatchBefore.countDown();
+        final DeviceConfig.OnPropertiesChangedListener countDownLatchAfterListener =
+                properties -> countDownLatchAfter.countDown();
+        DeviceConfig.addOnPropertiesChangedListener(NAMESPACE_FOR_TEST, mExecutor,
+                countDownLatchBeforeListener);
+
+        try {
+            // We update disabled values
+            updateProperty(/* key */ "key3", /* value */ false);
+            updateProperty(/* key */ "key4", /* value */ true);
+
+            assertThat(countDownLatchBefore.await(
+                    WAIT_FOR_PROPERTY_CHANGE_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)).isTrue();
+
+            // We check they haven't been updated
+            assertFlagValue(/* key */ "key3", /* expected */ false);
+            assertFlagValue(/* key */ "key4", /* expected */ false);
+
+
+            DeviceConfig.removeOnPropertiesChangedListener(countDownLatchBeforeListener);
+            DeviceConfig.addOnPropertiesChangedListener(NAMESPACE_FOR_TEST, mExecutor,
+                    countDownLatchAfterListener);
+
+            // We update enabled flags
+            updateProperty(/* key */ "key1", /* value */ false);
+            updateProperty(/* key */ "key2", /* value */ true);
+
+            assertThat(countDownLatchAfter.await(
+                    WAIT_FOR_PROPERTY_CHANGE_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)).isTrue();
+
+            // Value have been updated
+            assertFlagValue(/* key */ "key1", /* expected */ false);
+            assertFlagValue(/* key */ "key2", /* expected */ true);
+
+        } catch (InterruptedException e) {
+            Assert.fail(e.getMessage());
+        } finally {
+            DeviceConfig.removeOnPropertiesChangedListener(countDownLatchAfterListener);
+        }
+    }
+
+
+    private void assertFlagValue(String key, boolean expectedValue) {
+        assertEquals(/* message */"Flag " + key + " value is not " + expectedValue, /* expected */
+                expectedValue, /* actual */ mDeviceConfig.getFlagValue(key));
+    }
+
+
+    private void assertFlagEnabled(String key, boolean expectedValue) {
+        assertEquals(/* message */
+                "Flag " + key + " enabled is not " + expectedValue, /* expected */
+                expectedValue, /* actual */ mDeviceConfig.isBuildTimeFlagEnabled(key));
+    }
+
+    private void updateProperty(String key, Boolean value) {
+        DeviceConfig.setProperty(NAMESPACE_FOR_TEST, key, /* value */
+                value.toString(), /* makeDefault */ false);
+    }
+}