[NS B09] Create NetworkRanker
Bug: 113554781
Test: FrameworksNetTests
Change-Id: Ia534247144f479fe896e1a6e05b906103cd10005
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index feea30f..a06cc95 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -194,6 +194,7 @@
import com.android.server.connectivity.NetworkDiagnostics;
import com.android.server.connectivity.NetworkNotificationManager;
import com.android.server.connectivity.NetworkNotificationManager.NotificationType;
+import com.android.server.connectivity.NetworkRanker;
import com.android.server.connectivity.PermissionMonitor;
import com.android.server.connectivity.ProxyTracker;
import com.android.server.connectivity.Vpn;
@@ -579,6 +580,7 @@
final ConnectivityDiagnosticsHandler mConnectivityDiagnosticsHandler;
private final DnsManager mDnsManager;
+ private final NetworkRanker mNetworkRanker;
private boolean mSystemReady;
private Intent mInitialBroadcast;
@@ -958,6 +960,7 @@
mMetricsLog = logger;
mDefaultRequest = createDefaultInternetRequestForTransport(-1, NetworkRequest.Type.REQUEST);
+ mNetworkRanker = new NetworkRanker();
NetworkRequestInfo defaultNRI = new NetworkRequestInfo(null, mDefaultRequest, new Binder());
mNetworkRequests.put(mDefaultRequest, defaultNRI);
mNetworkRequestInfoLogs.log("REGISTER " + defaultNRI);
@@ -6660,24 +6663,12 @@
changes.addRematchedNetwork(new NetworkReassignment.NetworkBgStatePair(nai,
nai.isBackgroundNetwork()));
}
- Collections.sort(nais);
for (final NetworkRequestInfo nri : mNetworkRequests.values()) {
if (nri.request.isListen()) continue;
- // Find the top scoring network satisfying this request.
- NetworkAgentInfo bestNetwork = null;
- for (final NetworkAgentInfo nai : nais) {
- if (!nai.satisfies(nri.request)) continue;
- bestNetwork = nai;
- // As the nais are sorted by score, this is the top-scoring network that can
- // satisfy this request. The best network for this request has been found,
- // go process the next NRI
- break;
- }
- // If no NAI satisfies this request, bestNetwork is still null. That's fine : it
- // means no network can satisfy the request. If nri.mSatisfier is not null, it just
- // means the network that used to satisfy the request stopped satisfying it.
- if (nri.mSatisfier != bestNetwork) {
+ final NetworkAgentInfo bestNetwork = mNetworkRanker.getBestNetwork(nri.request, nais);
+ if (bestNetwork != nri.mSatisfier) {
+ // bestNetwork may be null if no network can satisfy this request.
changes.addRequestReassignment(new NetworkReassignment.RequestReassignment(
nri, nri.mSatisfier, bestNetwork));
}
diff --git a/services/core/java/com/android/server/connectivity/NetworkRanker.java b/services/core/java/com/android/server/connectivity/NetworkRanker.java
new file mode 100644
index 0000000..d0aabf9
--- /dev/null
+++ b/services/core/java/com/android/server/connectivity/NetworkRanker.java
@@ -0,0 +1,50 @@
+/*
+ * 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.connectivity;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.NetworkRequest;
+
+import java.util.Collection;
+
+/**
+ * A class that knows how to find the best network matching a request out of a list of networks.
+ */
+public class NetworkRanker {
+ public NetworkRanker() { }
+
+ /**
+ * Find the best network satisfying this request among the list of passed networks.
+ */
+ // Almost equivalent to Collections.max(nais), but allows returning null if no network
+ // satisfies the request.
+ @Nullable
+ public NetworkAgentInfo getBestNetwork(@NonNull final NetworkRequest request,
+ @NonNull final Collection<NetworkAgentInfo> nais) {
+ NetworkAgentInfo bestNetwork = null;
+ int bestScore = Integer.MIN_VALUE;
+ for (final NetworkAgentInfo nai : nais) {
+ if (!nai.satisfies(request)) continue;
+ if (nai.getCurrentScore() > bestScore) {
+ bestNetwork = nai;
+ bestScore = nai.getCurrentScore();
+ }
+ }
+ return bestNetwork;
+ }
+}
diff --git a/tests/net/java/com/android/server/connectivity/NetworkRankerTest.kt b/tests/net/java/com/android/server/connectivity/NetworkRankerTest.kt
new file mode 100644
index 0000000..86c9116
--- /dev/null
+++ b/tests/net/java/com/android/server/connectivity/NetworkRankerTest.kt
@@ -0,0 +1,84 @@
+/*
+ * 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.connectivity
+
+import android.net.NetworkRequest
+import androidx.test.filters.SmallTest
+import androidx.test.runner.AndroidJUnit4
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mockito.doReturn
+import org.mockito.Mockito.mock
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+@RunWith(AndroidJUnit4::class)
+@SmallTest
+class NetworkRankerTest {
+ private val ranker = NetworkRanker()
+
+ private fun makeNai(satisfy: Boolean, score: Int) = mock(NetworkAgentInfo::class.java).also {
+ doReturn(satisfy).`when`(it).satisfies(any())
+ doReturn(score).`when`(it).currentScore
+ }
+
+ @Test
+ fun testGetBestNetwork() {
+ val scores = listOf(20, 50, 90, 60, 23, 68)
+ val nais = scores.map { makeNai(true, it) }
+ val bestNetwork = nais[2] // The one with the top score
+ val someRequest = mock(NetworkRequest::class.java)
+ assertEquals(bestNetwork, ranker.getBestNetwork(someRequest, nais))
+ }
+
+ @Test
+ fun testIgnoreNonSatisfying() {
+ val nais = listOf(makeNai(true, 20), makeNai(true, 50), makeNai(false, 90),
+ makeNai(false, 60), makeNai(true, 23), makeNai(false, 68))
+ val bestNetwork = nais[1] // Top score that's satisfying
+ val someRequest = mock(NetworkRequest::class.java)
+ assertEquals(bestNetwork, ranker.getBestNetwork(someRequest, nais))
+ }
+
+ @Test
+ fun testNoMatch() {
+ val nais = listOf(makeNai(false, 20), makeNai(false, 50), makeNai(false, 90))
+ val someRequest = mock(NetworkRequest::class.java)
+ assertNull(ranker.getBestNetwork(someRequest, nais))
+ }
+
+ @Test
+ fun testEmpty() {
+ val someRequest = mock(NetworkRequest::class.java)
+ assertNull(ranker.getBestNetwork(someRequest, emptyList()))
+ }
+
+ // Make sure the ranker is "stable" (as in stable sort), that is, it always returns the FIRST
+ // network satisfying the request if multiple of them have the same score.
+ @Test
+ fun testStable() {
+ val nais1 = listOf(makeNai(true, 30), makeNai(true, 30), makeNai(true, 30),
+ makeNai(true, 30), makeNai(true, 30), makeNai(true, 30))
+ val someRequest = mock(NetworkRequest::class.java)
+ assertEquals(nais1[0], ranker.getBestNetwork(someRequest, nais1))
+
+ val nais2 = listOf(makeNai(true, 30), makeNai(true, 50), makeNai(true, 20),
+ makeNai(true, 50), makeNai(true, 50), makeNai(true, 40))
+ assertEquals(nais2[1], ranker.getBestNetwork(someRequest, nais2))
+ }
+}