Merge "Add WakeupLock."
diff --git a/service/java/com/android/server/wifi/WakeupLock.java b/service/java/com/android/server/wifi/WakeupLock.java
new file mode 100644
index 0000000..73cda91
--- /dev/null
+++ b/service/java/com/android/server/wifi/WakeupLock.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2017 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.wifi;
+
+import android.util.ArrayMap;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * A lock to determine whether Auto Wifi can re-enable Wifi.
+ *
+ * <p>Wakeuplock manages a list of networks to determine whether the device's location has changed.
+ */
+public class WakeupLock {
+
+    @VisibleForTesting
+    static final int CONSECUTIVE_MISSED_SCANS_REQUIRED_TO_EVICT = 3;
+
+    private Map<ScanResultMatchInfo, Integer> mLockedNetworks = new ArrayMap<>();
+
+    // TODO(easchwar) read initial value of mLockedNetworks from file
+    public WakeupLock() {
+    }
+
+    /**
+     * Initializes the WakeupLock with the given {@link ScanResultMatchInfo} list.
+     *
+     * @param scanResultList list of ScanResultMatchInfos to start the lock with
+     */
+    public void initialize(Collection<ScanResultMatchInfo> scanResultList) {
+        mLockedNetworks.clear();
+        for (ScanResultMatchInfo scanResultMatchInfo : scanResultList) {
+            mLockedNetworks.put(scanResultMatchInfo, CONSECUTIVE_MISSED_SCANS_REQUIRED_TO_EVICT);
+        }
+    }
+
+    /**
+     * Updates the lock with the given {@link ScanResultMatchInfo} list.
+     *
+     * <p>If a network in the lock is not present in the list, reduce the number of scans
+     * required to evict by one. Remove any entries in the list with 0 scans required to evict.
+     *
+     * @param scanResultList list of present ScanResultMatchInfos to update the lock with
+     */
+    public void update(Collection<ScanResultMatchInfo> scanResultList) {
+        Iterator<Map.Entry<ScanResultMatchInfo, Integer>> it =
+                mLockedNetworks.entrySet().iterator();
+        while (it.hasNext()) {
+            Map.Entry<ScanResultMatchInfo, Integer> entry = it.next();
+
+            // if present in scan list, reset to max
+            if (scanResultList.contains(entry.getKey())) {
+                entry.setValue(CONSECUTIVE_MISSED_SCANS_REQUIRED_TO_EVICT);
+                continue;
+            }
+
+            // decrement and remove if necessary
+            entry.setValue(entry.getValue() - 1);
+            if (entry.getValue() <= 0) {
+                it.remove();
+            }
+        }
+        // TODO(easchwar) write the updated list to file
+    }
+
+    /**
+     * Returns whether the internal network set is empty.
+     */
+    public boolean isEmpty() {
+        return mLockedNetworks.isEmpty();
+    }
+}
diff --git a/tests/wifitests/src/com/android/server/wifi/WakeupLockTest.java b/tests/wifitests/src/com/android/server/wifi/WakeupLockTest.java
new file mode 100644
index 0000000..bad9e3a
--- /dev/null
+++ b/tests/wifitests/src/com/android/server/wifi/WakeupLockTest.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2017 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.wifi;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Unit tests for {@link WakeupLock}.
+ */
+public class WakeupLockTest {
+
+    private static final String SSID_1 = "ssid1";
+    private static final String SSID_2 = "ssid2";
+
+    private ScanResultMatchInfo mNetwork1;
+    private ScanResultMatchInfo mNetwork2;
+    private WakeupLock mWakeupLock;
+
+    /**
+     * Initialize objects before each test run.
+     */
+    @Before
+    public void setUp() {
+        mNetwork1 = new ScanResultMatchInfo();
+        mNetwork1.networkSsid = SSID_1;
+        mNetwork1.networkType = ScanResultMatchInfo.NETWORK_TYPE_OPEN;
+
+        mNetwork2 = new ScanResultMatchInfo();
+        mNetwork2.networkSsid = SSID_2;
+        mNetwork2.networkType = ScanResultMatchInfo.NETWORK_TYPE_EAP;
+
+        mWakeupLock = new WakeupLock();
+    }
+
+    /**
+     * Updates the lock enough times to evict any networks not passed in.
+     *
+     * <p>It calls update {@link WakeupLock#CONSECUTIVE_MISSED_SCANS_REQUIRED_TO_EVICT} times with
+     * the given network list. It asserts that the lock isn't empty prior to each call to update.
+     */
+    private void updateEnoughTimesToEvictWithAsserts(Collection<ScanResultMatchInfo> networks) {
+        for (int i = 0; i < WakeupLock.CONSECUTIVE_MISSED_SCANS_REQUIRED_TO_EVICT; i++) {
+            assertFalse("Lock empty after " + i + " scans", mWakeupLock.isEmpty());
+            mWakeupLock.update(networks);
+        }
+    }
+
+    /**
+     * Verify that the WakeupLock is not empty immediately after being initialized with networks.
+     */
+    @Test
+    public void verifyNotEmptyWhenInitializedWithNetworkList() {
+        mWakeupLock.initialize(Arrays.asList(mNetwork1, mNetwork2));
+        assertFalse(mWakeupLock.isEmpty());
+    }
+
+    /**
+     * Verify that the WakeupLock is empty when initialized with an empty list.
+     */
+    @Test
+    public void isEmptyWhenInitializedWithEmptyList() {
+        mWakeupLock.initialize(Collections.emptyList());
+        assertTrue(mWakeupLock.isEmpty());
+    }
+
+    /**
+     * Verify that initializing the WakeupLock clears out previous entries.
+     */
+    @Test
+    public void initializingLockClearsPreviousNetworks() {
+        mWakeupLock.initialize(Collections.singletonList(mNetwork1));
+        assertFalse(mWakeupLock.isEmpty());
+
+        mWakeupLock.initialize(Collections.emptyList());
+        assertTrue(mWakeupLock.isEmpty());
+    }
+
+    /**
+     * Updating the lock should evict scan results that haven't been seen in
+     * {@link WakeupLock#CONSECUTIVE_MISSED_SCANS_REQUIRED_TO_EVICT} scans.
+     */
+    @Test
+    public void updateShouldRemoveNetworksAfterConsecutiveMissedScans() {
+        mWakeupLock.initialize(Collections.singletonList(mNetwork1));
+
+        updateEnoughTimesToEvictWithAsserts(Collections.singletonList(mNetwork2));
+
+        assertTrue(mWakeupLock.isEmpty());
+    }
+
+    /**
+     * Ensure that missed scans must be consecutive in order to evict networks from lock.
+     */
+    @Test
+    public void updateWithLockedNetworkShouldResetRequiredNumberOfScans() {
+        List<ScanResultMatchInfo> lockedNetworks = Collections.singletonList(mNetwork1);
+        List<ScanResultMatchInfo> updateNetworks = Collections.singletonList(mNetwork2);
+
+        mWakeupLock.initialize(lockedNetworks);
+
+        // one update without network
+        mWakeupLock.update(updateNetworks);
+        // one update with network
+        mWakeupLock.update(lockedNetworks);
+
+        updateEnoughTimesToEvictWithAsserts(updateNetworks);
+
+        assertTrue(mWakeupLock.isEmpty());
+    }
+
+    /**
+     * Once a network is removed from the lock, it should not be reset even if it's seen again.
+     */
+    @Test
+    public void updateWithLockedNetworkAfterItIsRemovedDoesNotReset() {
+        List<ScanResultMatchInfo> lockedNetworks = Collections.singletonList(mNetwork1);
+        mWakeupLock.initialize(lockedNetworks);
+
+        updateEnoughTimesToEvictWithAsserts(Collections.emptyList());
+
+        assertTrue(mWakeupLock.isEmpty());
+        mWakeupLock.update(lockedNetworks);
+        assertTrue(mWakeupLock.isEmpty());
+    }
+
+    /**
+     * Verify that networks can be incrementally removed from the lock. Their counters should be
+     * independent.
+     */
+    @Test
+    public void networksCanBeRemovedIncrementallyFromLock() {
+        List<ScanResultMatchInfo> lockedNetworks = Arrays.asList(mNetwork1, mNetwork2);
+        mWakeupLock.initialize(lockedNetworks);
+
+        updateEnoughTimesToEvictWithAsserts(Collections.singletonList(mNetwork1));
+        assertFalse(mWakeupLock.isEmpty());
+
+        updateEnoughTimesToEvictWithAsserts(Collections.singletonList(mNetwork2));
+        assertTrue(mWakeupLock.isEmpty());
+    }
+}