Merge "Create and implement a CacheListener inside WifiNetworkScoreCache."

am: 31a8f712ab

Change-Id: Iba52c9ed85a7e35c46b85a9516a81ac5096a6710

wifi/java/android/net/wifi/WifiNetworkScoreCache.java

@@ -17,13 +17,19 @@
 package android.net.wifi;
 
 import android.Manifest.permission;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.content.Context;
+import android.os.Handler;
 import android.net.INetworkScoreCache;
 import android.net.NetworkKey;
 import android.net.ScoredNetwork;
 import android.util.Log;
 
+import com.android.internal.util.Preconditions;
+import com.android.internal.annotations.GuardedBy;
+
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.util.HashMap;
@@ -43,22 +49,41 @@ public class WifiNetworkScoreCache extends INetworkScoreCache.Stub {
     // We treat the lowest possible score as though there were no score, effectively allowing the
     // scorer to provide an RSSI threshold below which a network should not be used.
     public static final int INVALID_NETWORK_SCORE = Byte.MIN_VALUE;
+
+    // See {@link #CacheListener}.
+    @Nullable
+    @GuardedBy("mCacheLock")
+    private CacheListener mListener;
+
     private final Context mContext;
+    private final Object mCacheLock = new Object();
 
     // The key is of the form "<ssid>"<bssid>
     // TODO: What about SSIDs that can't be encoded as UTF-8?
     private final Map<String, ScoredNetwork> mNetworkCache;
 
+
     public WifiNetworkScoreCache(Context context) {
-        mContext = context;
+        this(context, null /* listener */);
+    }
+
+    /**
+     * Instantiates a WifiNetworkScoreCache.
+     *
+     * @param context Application context
+     * @param listener CacheListener for cache updates
+     */
+    public WifiNetworkScoreCache(Context context, @Nullable CacheListener listener) {
+        mContext = context.getApplicationContext();
+        mListener = listener;
         mNetworkCache = new HashMap<String, ScoredNetwork>();
     }
 
     @Override public final void updateScores(List<ScoredNetwork> networks) {
-      if (networks == null) {
+        if (networks == null || networks.isEmpty()) {
            return;
         }
-       Log.e(TAG, "updateScores list size=" + networks.size());
+        Log.d(TAG, "updateScores list size=" + networks.size());
 
         synchronized(mNetworkCache) {
             for (ScoredNetwork network : networks) {
@@ -67,6 +92,12 @@ public class WifiNetworkScoreCache extends INetworkScoreCache.Stub {
                 mNetworkCache.put(networkKey, network);
             }
         }
+
+        synchronized (mCacheLock) {
+            if (mListener != null) {
+                mListener.post(networks);
+            }
+        }
     }
 
     @Override public final void clearScores() {
@@ -193,4 +224,53 @@ public class WifiNetworkScoreCache extends INetworkScoreCache.Stub {
         }
     }
 
+    /** Registers a CacheListener instance, replacing the previous listener if it existed. */
+    public void registerListener(CacheListener listener) {
+        synchronized (mCacheLock) {
+            mListener = listener;
+        }
+    }
+
+    /** Removes the registered CacheListener. */
+    public void unregisterListener() {
+        synchronized (mCacheLock) {
+            mListener = null;
+        }
+    }
+
+    /** Listener for updates to the cache inside WifiNetworkScoreCache. */
+    public abstract static class CacheListener {
+
+        private Handler mHandler;
+
+        /**
+         * Constructor for CacheListener.
+         *
+         * @param handler the Handler on which to invoke the {@link #networkCacheUpdated} method.
+         *          This cannot be null.
+         */
+        public CacheListener(@NonNull Handler handler) {
+            Preconditions.checkNotNull(handler);
+            mHandler = handler;
+        }
+
+        /** Invokes the {@link #networkCacheUpdated(List<ScoredNetwork>)} method on the handler. */
+        void post(List<ScoredNetwork> updatedNetworks) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    networkCacheUpdated(updatedNetworks);
+                }
+            });
+        }
+
+        /**
+         * Invoked whenever the cache is updated.
+         *
+         * <p>Clearing the cache does not invoke this method.
+         *
+         * @param updatedNetworks the networks that were updated
+         */
+        public abstract void networkCacheUpdated(List<ScoredNetwork> updatedNetworks);
+    }
 }

wifi/tests/src/android/net/wifi/WifiNetworkScoreCacheTest.java

@@ -17,6 +17,8 @@
 package android.net.wifi;
 
 import static org.junit.Assert.*;
+import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.content.Context;
@@ -24,6 +26,9 @@ import android.net.NetworkKey;
 import android.net.RssiCurve;
 import android.net.ScoredNetwork;
 import android.net.WifiKey;
+import android.net.wifi.WifiNetworkScoreCache.CacheListener;
+import android.os.Handler;
+import android.os.HandlerThread;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
 
@@ -33,17 +38,21 @@ import org.junit.Rule;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+
 /** Unit tests for {@link WifiNetworkScoreCache}. */
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public class WifiNetworkScoreCacheTest {
 
-  @Mock public Context mockContext; // isn't used, can be null
-  @Mock private RssiCurve mockRssiCurve;
-
     public static final String SSID = "ssid";
     public static final String FORMATTED_SSID = "\"" + SSID + "\"";
     public static final String BSSID = "AA:AA:AA:AA:AA:AA";
@@ -52,6 +61,15 @@ public class WifiNetworkScoreCacheTest {
 
     public static final ScanResult VALID_SCAN_RESULT = buildScanResult(SSID, BSSID);
 
+    @Mock private Context mockApplicationContext;
+    @Mock private Context mockContext; // isn't used, can be null
+    @Mock private RssiCurve mockRssiCurve;
+
+
+    private CacheListener mCacheListener;
+    private CountDownLatch mLatch;
+    private Handler mHandler;
+    private List<ScoredNetwork> mUpdatedNetworksCaptor;
     private ScoredNetwork mValidScoredNetwork;
     private WifiNetworkScoreCache mScoreCache =
                 new WifiNetworkScoreCache(mockContext);
@@ -80,9 +98,24 @@ public class WifiNetworkScoreCacheTest {
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
+
+        when(mockContext.getApplicationContext()).thenReturn(mockApplicationContext);
+
         mValidScoredNetwork = buildScoredNetwork(VALID_KEY, mockRssiCurve);
         mScoreCache = new WifiNetworkScoreCache(mockContext);
         initializeCacheWithValidScoredNetwork();
+
+        HandlerThread thread = new HandlerThread("WifiNetworkScoreCacheTest Handler Thread");
+        thread.start();
+        mHandler = new Handler(thread.getLooper());
+        mLatch = new CountDownLatch(1);
+        mCacheListener = new CacheListener(mHandler) {
+            @Override
+            public void networkCacheUpdated(List<ScoredNetwork> updatedNetworks) {
+                mUpdatedNetworksCaptor = updatedNetworks;
+                mLatch.countDown();
+            }
+        };
     }
 
 
@@ -148,9 +181,24 @@ public class WifiNetworkScoreCacheTest {
     @Test
     public void getMeteredHintShouldReturnTrue() {
         ScoredNetwork network =
-        new ScoredNetwork(new NetworkKey(VALID_KEY), mockRssiCurve, true /* metered Hint */);
+                new ScoredNetwork(
+                    new NetworkKey(VALID_KEY), mockRssiCurve, true /* metered Hint */);
         mScoreCache.updateScores(ImmutableList.of(network));
 
         assertTrue(mScoreCache.getMeteredHint(VALID_SCAN_RESULT));
     }
+
+    @Test
+    public void updateScoresShouldInvokeCacheListener_networkCacheUpdated() {
+        mScoreCache = new WifiNetworkScoreCache(mockContext, mCacheListener);
+        initializeCacheWithValidScoredNetwork();
+
+        try {
+            mLatch.await(1, TimeUnit.SECONDS); // wait for listener to be executed
+        } catch (InterruptedException e) {
+            fail("Interrupted Exception while waiting for listener to be invoked.");
+        }
+        assertEquals("One network should be updated", 1, mUpdatedNetworksCaptor.size());
+        assertEquals(mValidScoredNetwork, mUpdatedNetworksCaptor.get(0));
+    }
 }