Add a class for retrieving server flag values

Also adding two flags for previously hardcoded timeout values to test
out the new flag system.

The reason for adding a util class is to avoid calling DeviceConfig and
passing in the same strings every time a flag value is retrieved.

Bug: 210083465
Test: atest BackupAndRestoreFeatureFlagsTest.java
  Manual:
    adb shell device_config put backup_and_restore backup_transport_callback_timeout_millis 1
      Observe that transport status callbacks fail with a timeout error
    adb shell device_config put backup_and_restore backup_transport_future_timeout_millis 1
      Observe that many transport futures timeout
  Note that the timeouts that turned into flags are not unit-testable since
  they use the system clock to keep track of time. AFAIU this can't be
  mocked.
Change-Id: I6953fd480ec217a854a57e3c369cadb0947bd55c

5 files changed, 135 insertions, 4 deletions

diff --git a/services/backup/java/com/android/server/backup/BackupAndRestoreFeatureFlags.java b/services/backup/java/com/android/server/backup/BackupAndRestoreFeatureFlags.java
new file mode 100644
index 000000000000..042bcbd0a0bb
--- /dev/null
+++ b/services/backup/java/com/android/server/backup/BackupAndRestoreFeatureFlags.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2022 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.backup;
+
+import android.Manifest;
+import android.annotation.RequiresPermission;
+import android.provider.DeviceConfig;
+
+/**
+ * Retrieves values of feature flags.
+ *
+ * <p>These flags are intended to be configured server-side and their values should be set in {@link
+ * DeviceConfig} by a service that periodically syncs with the server.
+ *
+ * <p>This class must ensure that the namespace, flag name, and default value passed into {@link
+ * DeviceConfig} matches what's declared on the server. The namespace is shared for all backup and
+ * restore flags.
+ */
+public class BackupAndRestoreFeatureFlags {
+    private static final String NAMESPACE = "backup_and_restore";
+
+    private BackupAndRestoreFeatureFlags() {}
+
+    /** Retrieves the value of the flag "backup_transport_future_timeout_millis". */
+    @RequiresPermission(Manifest.permission.READ_DEVICE_CONFIG)
+    public static long getBackupTransportFutureTimeoutMillis() {
+        return DeviceConfig.getLong(
+                NAMESPACE,
+                /* name= */ "backup_transport_future_timeout_millis",
+                /* defaultValue= */ 600000); // 10 minutes
+    }
+
+    /** Retrieves the value of the flag "backup_transport_callback_timeout_millis". */
+    @RequiresPermission(Manifest.permission.READ_DEVICE_CONFIG)
+    public static long getBackupTransportCallbackTimeoutMillis() {
+        return DeviceConfig.getLong(
+                NAMESPACE,
+                /* name= */ "backup_transport_callback_timeout_millis",
+                /* defaultValue= */ 300000); // 5 minutes
+    }
+}
diff --git a/services/backup/java/com/android/server/backup/transport/BackupTransportClient.java b/services/backup/java/com/android/server/backup/transport/BackupTransportClient.java
index 40d7cad9405a..21005bbf8af9 100644
--- a/services/backup/java/com/android/server/backup/transport/BackupTransportClient.java
+++ b/services/backup/java/com/android/server/backup/transport/BackupTransportClient.java
@@ -30,6 +30,7 @@ import android.util.Slog;
 
 import com.android.internal.backup.IBackupTransport;
 import com.android.internal.infra.AndroidFuture;
+import com.android.server.backup.BackupAndRestoreFeatureFlags;
 
 import java.util.ArrayDeque;
 import java.util.HashSet;
@@ -385,7 +386,8 @@ public class BackupTransportClient {
 
     private <T> T getFutureResult(AndroidFuture<T> future) {
         try {
-            return future.get(600, TimeUnit.SECONDS);
+            return future.get(BackupAndRestoreFeatureFlags.getBackupTransportFutureTimeoutMillis(),
+                    TimeUnit.MILLISECONDS);
         } catch (InterruptedException | ExecutionException | TimeoutException
                  | CancellationException e) {
             Slog.w(TAG, "Failed to get result from transport:", e);
diff --git a/services/backup/java/com/android/server/backup/transport/TransportStatusCallback.java b/services/backup/java/com/android/server/backup/transport/TransportStatusCallback.java
index fb98825f1343..deaa86c09b36 100644
--- a/services/backup/java/com/android/server/backup/transport/TransportStatusCallback.java
+++ b/services/backup/java/com/android/server/backup/transport/TransportStatusCallback.java
@@ -23,13 +23,13 @@ import android.util.Slog;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.backup.ITransportStatusCallback;
+import com.android.server.backup.BackupAndRestoreFeatureFlags;
 
 public class TransportStatusCallback extends ITransportStatusCallback.Stub {
     private static final String TAG = "TransportStatusCallback";
-    private static final int TIMEOUT_MILLIS = 300 * 1000; // 5 minutes.
     private static final int OPERATION_STATUS_DEFAULT = 0;
 
-    private final int mOperationTimeout;
+    private final long mOperationTimeout;
 
     @GuardedBy("this")
     private int mOperationStatus = OPERATION_STATUS_DEFAULT;
@@ -37,7 +37,7 @@ public class TransportStatusCallback extends ITransportStatusCallback.Stub {
     private boolean mHasCompletedOperation = false;
 
     public TransportStatusCallback() {
-        mOperationTimeout = TIMEOUT_MILLIS;
+        mOperationTimeout = BackupAndRestoreFeatureFlags.getBackupTransportCallbackTimeoutMillis();
     }
 
     @VisibleForTesting
diff --git a/services/tests/mockingservicestests/Android.bp b/services/tests/mockingservicestests/Android.bp
index 73b1907c9f42..681bfcf68cc3 100644
--- a/services/tests/mockingservicestests/Android.bp
+++ b/services/tests/mockingservicestests/Android.bp
@@ -56,6 +56,7 @@ android_test {
         "service-jobscheduler",
         "service-permission.impl",
         "service-sdksandbox.impl",
+        "services.backup",
         "services.companion",
         "services.core",
         "services.devicepolicy",
diff --git a/services/tests/mockingservicestests/src/com/android/server/backup/BackupAndRestoreFeatureFlagsTest.java b/services/tests/mockingservicestests/src/com/android/server/backup/BackupAndRestoreFeatureFlagsTest.java
new file mode 100644
index 000000000000..f53599731e10
--- /dev/null
+++ b/services/tests/mockingservicestests/src/com/android/server/backup/BackupAndRestoreFeatureFlagsTest.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2022 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.backup;
+
+import android.platform.test.annotations.Presubmit;
+import android.provider.DeviceConfig;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import com.android.modules.utils.testing.TestableDeviceConfig;
+
+import static com.google.common.truth.Truth.assertThat;
+
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@Presubmit
+@RunWith(AndroidJUnit4.class)
+public class BackupAndRestoreFeatureFlagsTest {
+    @Rule
+    public TestableDeviceConfig.TestableDeviceConfigRule
+            mDeviceConfigRule = new TestableDeviceConfig.TestableDeviceConfigRule();
+
+    @Test
+    public void getBackupTransportFutureTimeoutMillis_notSet_returnsDefault() {
+        assertThat(
+                BackupAndRestoreFeatureFlags.getBackupTransportFutureTimeoutMillis()).isEqualTo(
+                600000);
+    }
+
+    @Test
+    public void getBackupTransportFutureTimeoutMillis_set_returnsSetValue() {
+        DeviceConfig.setProperty("backup_and_restore", "backup_transport_future_timeout_millis",
+                "1234", false);
+
+        assertThat(
+                BackupAndRestoreFeatureFlags.getBackupTransportFutureTimeoutMillis()).isEqualTo(
+                1234);
+    }
+
+    @Test
+    public void getBackupTransportCallbackTimeoutMillis_notSet_returnsDefault() {
+        assertThat(
+                BackupAndRestoreFeatureFlags.getBackupTransportCallbackTimeoutMillis()).isEqualTo(
+                300000);
+    }
+
+    @Test
+    public void getBackupTransportCallbackTimeoutMillis_set_returnsSetValue() {
+        DeviceConfig.setProperty("backup_and_restore", "backup_transport_callback_timeout_millis",
+                "5678", false);
+
+        assertThat(
+                BackupAndRestoreFeatureFlags.getBackupTransportCallbackTimeoutMillis()).isEqualTo(
+                5678);
+    }
+}