Adding emptyTreatment() and emptySelector()

Note: There was a change that adds a DROP action to
a traffic treatment if there are no other actions present.
To get a traffic treatment without the drop rule, use
emptyTreatment()

Change-Id: I1f23ed5e1fa7519eb94fcafa85facbad815d5e9c

@@ -205,8 +205,8 @@ public class DemoInstaller implements DemoAPI {
 
         @Override
         public void run() {
-            TrafficSelector selector = DefaultTrafficSelector.builder().build();
-            TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+            TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+            TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
             List<Constraint> constraint = Lists.newArrayList();
             List<Host> hosts = Lists.newArrayList(hostService.getHosts());
             while (!hosts.isEmpty()) {
@@ -405,8 +405,8 @@ public class DemoInstaller implements DemoAPI {
             private final Host src;
             private final Host dst;
 
-            private final TrafficSelector selector = DefaultTrafficSelector.builder().build();
-            private final TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+            private final TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+            private final TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
             private final List<Constraint> constraint = Lists.newArrayList();
             private final HostToHostIntent intent;
 

@@ -157,8 +157,8 @@ public class IntentReactiveForwarding {
 
     // Install a rule forwarding the packet to the specified port.
     private void setUpConnectivity(PacketContext context, HostId srcId, HostId dstId) {
-        TrafficSelector selector = DefaultTrafficSelector.builder().build();
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         HostToHostIntent intent = new HostToHostIntent(appId, srcId, dstId,
                                                        selector, treatment);

@@ -203,7 +203,7 @@ public class IntentPerfInstaller {
             //FIXME we currently ignore the path length and always use the same device
             TrafficSelector selector = DefaultTrafficSelector.builder()
                     .matchEthDst(MacAddress.valueOf(count)).build();
-            TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+            TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
             ConnectPoint ingress = new ConnectPoint(ingressDevice.id(), PortNumber.portNumber(1));
             ConnectPoint egress = new ConnectPoint(ingressDevice.id(), PortNumber.portNumber(2));
 

@@ -166,8 +166,7 @@ public class PeerConnectivityManager {
             return intents;
         }
 
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder()
-                .build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         TrafficSelector selector;
 

@@ -108,7 +108,7 @@ public class PeerConnectivityManagerTest extends AbstractIntentTest {
             new ConnectPoint(deviceId2, PortNumber.portNumber(1));
 
     private final TrafficTreatment noTreatment =
-            DefaultTrafficTreatment.builder().build();
+            DefaultTrafficTreatment.emptyTreatment();
 
     @Before
     public void setUp() throws Exception {

@@ -50,8 +50,8 @@ public class AddHostToHostIntentCommand extends ConnectivityIntentCommand {
         HostId oneId = HostId.hostId(one);
         HostId twoId = HostId.hostId(two);
 
-        TrafficSelector selector = DefaultTrafficSelector.builder().build();
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
         List<Constraint> constraints = buildConstraints();
 
         HostToHostIntent intent = new HostToHostIntent(appId(), key(),

@@ -68,7 +68,7 @@ public class AddSinglePointToMultiPointIntentCommand extends ConnectivityIntentC
         }
 
         TrafficSelector selector = buildTrafficSelector();
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
         List<Constraint> constraints = buildConstraints();
 
         SinglePointToMultiPointIntent intent =

@@ -120,7 +120,7 @@ public class IntentCycleCommand extends AbstractShellCommand
     private List<Intent> generateIntents(ConnectPoint ingress, ConnectPoint egress) {
         TrafficSelector.Builder selectorBldr = DefaultTrafficSelector.builder()
                 .matchEthType(Ethernet.TYPE_IPV4);
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         List<Intent> intents = Lists.newArrayList();
         for (int i = 0; i < count; i++) {

@@ -129,7 +129,7 @@ public class IntentPushTestCommand extends AbstractShellCommand
     private List<Intent> generateIntents(ConnectPoint ingress, ConnectPoint egress) {
         TrafficSelector.Builder selectorBldr = DefaultTrafficSelector.builder()
                 .matchEthType(Ethernet.TYPE_IPV4);
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         List<Intent> intents = Lists.newArrayList();
         for (int i = 0; i < count; i++) {

@@ -67,8 +67,8 @@ public class RandomIntentCommand extends AbstractShellCommand {
     }
 
     private Collection<Intent> generateIntents() {
-        TrafficSelector selector = DefaultTrafficSelector.builder().build();
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         List<Host> hosts = Lists.newArrayList(hostService.getHosts());
         List<Intent> fullMesh = Lists.newArrayList();

@@ -15,22 +15,22 @@
  */
 package org.onosproject.net.flow;
 
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-
-import org.onosproject.net.PortNumber;
-import org.onosproject.net.flow.criteria.Criteria;
-import org.onosproject.net.flow.criteria.Criterion;
-import org.onlab.packet.IpPrefix;
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableSet;
 import org.onlab.packet.Ip6Address;
+import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.MplsLabel;
 import org.onlab.packet.VlanId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.criteria.Criteria;
+import org.onosproject.net.flow.criteria.Criterion;
 
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.ImmutableSet;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
 
 /**
  * Default traffic selector implementation.
@@ -39,6 +39,9 @@ public final class DefaultTrafficSelector implements TrafficSelector {
 
     private final Set<Criterion> criteria;
 
+    private static final TrafficSelector EMPTY
+            = new DefaultTrafficSelector(Collections.emptySet());
+
     /**
      * Creates a new traffic selector with the specified criteria.
      *
@@ -98,6 +101,15 @@ public final class DefaultTrafficSelector implements TrafficSelector {
     }
 
     /**
+     * Returns an empty traffic selector.
+     *
+     * @return empty traffic selector
+     */
+    public static TrafficSelector emptySelector() {
+        return EMPTY;
+    }
+
+    /**
      * Returns a new traffic selector builder primed to produce entities
      * patterned after the supplied selector.
      *

@@ -27,6 +27,7 @@ import org.onosproject.net.PortNumber;
 import org.onosproject.net.flow.instructions.Instruction;
 import org.onosproject.net.flow.instructions.Instructions;
 
+import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
@@ -41,6 +42,9 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
 
     private final boolean hasClear;
 
+    private static final DefaultTrafficTreatment EMPTY
+            = new DefaultTrafficTreatment(Collections.emptyList());
+
     /**
      * Creates a new traffic treatment from the specified list of instructions.
      *
@@ -99,6 +103,15 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
     }
 
     /**
+     * Returns an empty traffic treatment.
+     *
+     * @return empty traffic treatment
+     */
+    public static TrafficTreatment emptyTreatment() {
+        return EMPTY;
+    }
+
+    /**
      * Returns a new traffic treatment builder primed to produce entities
      * patterned after the supplied treatment.
      *

@@ -273,12 +273,14 @@ public interface TrafficTreatment {
 
         /**
          * Builds an immutable traffic treatment descriptor.
+         * <p>
+         * If the treatment is empty when build() is called, it will add a default
+         * drop rule automatically. For a treatment that is actually empty, use
+         * {@link org.onosproject.net.flow.DefaultTrafficTreatment#emptyTreatment}.
+         * </p>
          *
          * @return traffic treatment
          */
         TrafficTreatment build();
-
-
     }
-
 }

@@ -50,8 +50,8 @@ public final class HostToHostIntent extends ConnectivityIntent {
      */
     public HostToHostIntent(ApplicationId appId, HostId one, HostId two) {
         this(appId, one, two,
-             DefaultTrafficSelector.builder().build(),
-             DefaultTrafficTreatment.builder().build(),
+             DefaultTrafficSelector.emptySelector(),
+             DefaultTrafficTreatment.emptyTreatment(),
              ImmutableList.of(new LinkTypeConstraint(false, Link.Type.OPTICAL)));
     }
 

@@ -51,8 +51,8 @@ public final class TwoWayP2PIntent extends ConnectivityIntent {
      */
     public TwoWayP2PIntent(ApplicationId appId, ConnectPoint one, ConnectPoint two) {
         this(appId, one, two,
-             DefaultTrafficSelector.builder().build(),
-             DefaultTrafficTreatment.builder().build(),
+             DefaultTrafficSelector.emptySelector(),
+             DefaultTrafficTreatment.emptyTreatment(),
              ImmutableList.of(new LinkTypeConstraint(false, Link.Type.OPTICAL)));
     }
 

@@ -35,8 +35,8 @@ public abstract class ConnectivityIntentTest extends IntentTest {
     public static final ApplicationId APPID = new TestApplicationId("foo");
 
     public static final IntentId IID = new IntentId(123);
-    public static final TrafficSelector MATCH = DefaultTrafficSelector.builder().build();
-    public static final TrafficTreatment NOP = DefaultTrafficTreatment.builder().build();
+    public static final TrafficSelector MATCH = DefaultTrafficSelector.emptySelector();
+    public static final TrafficTreatment NOP = DefaultTrafficTreatment.emptyTreatment();
 
     public static final ConnectPoint P1 = new ConnectPoint(DeviceId.deviceId("111"), PortNumber.portNumber(0x1));
     public static final ConnectPoint P2 = new ConnectPoint(DeviceId.deviceId("222"), PortNumber.portNumber(0x2));

@@ -63,8 +63,8 @@ public class CompilingTest {
 
     private final ApplicationId appId = new TestApplicationId("test");
     private final ProviderId pid = new ProviderId("of", "test");
-    private final TrafficSelector selector = DefaultTrafficSelector.builder().build();
-    private final TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+    private final TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+    private final TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
     private final ConnectPoint cp1 = new ConnectPoint(deviceId("1"), portNumber(1));
     private final ConnectPoint cp2 = new ConnectPoint(deviceId("1"), portNumber(2));
     private final ConnectPoint cp3 = new ConnectPoint(deviceId("2"), portNumber(1));

@@ -64,8 +64,8 @@ public class InstallCoordinatingTest {
 
     private final ApplicationId appId = new TestApplicationId("test");
     private final ProviderId pid = new ProviderId("of", "test");
-    private final TrafficSelector selector = DefaultTrafficSelector.builder().build();
-    private final TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+    private final TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+    private final TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
     private final ConnectPoint cp1 = new ConnectPoint(deviceId("1"), portNumber(1));
     private final ConnectPoint cp2 = new ConnectPoint(deviceId("1"), portNumber(2));
     private final ConnectPoint cp3 = new ConnectPoint(deviceId("2"), portNumber(1));

@@ -64,8 +64,8 @@ public class InstallingTest {
 
     private final ApplicationId appId = new TestApplicationId("test");
     private final ProviderId pid = new ProviderId("of", "test");
-    private final TrafficSelector selector = DefaultTrafficSelector.builder().build();
-    private final TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+    private final TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+    private final TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
     private final ConnectPoint cp1 = new ConnectPoint(deviceId("1"), portNumber(1));
     private final ConnectPoint cp2 = new ConnectPoint(deviceId("1"), portNumber(2));
     private final ConnectPoint cp3 = new ConnectPoint(deviceId("2"), portNumber(1));

@@ -65,8 +65,8 @@ public class WithdrawCoordinatingTest {
 
     private final ApplicationId appId = new TestApplicationId("test");
     private final ProviderId pid = new ProviderId("of", "test");
-    private final TrafficSelector selector = DefaultTrafficSelector.builder().build();
-    private final TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+    private final TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+    private final TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
     private final ConnectPoint cp1 = new ConnectPoint(deviceId("1"), portNumber(1));
     private final ConnectPoint cp2 = new ConnectPoint(deviceId("1"), portNumber(2));
     private final ConnectPoint cp3 = new ConnectPoint(deviceId("2"), portNumber(1));

@@ -63,8 +63,8 @@ public class WithdrawingTest {
 
     private final ApplicationId appId = new TestApplicationId("test");
     private final ProviderId pid = new ProviderId("of", "test");
-    private final TrafficSelector selector = DefaultTrafficSelector.builder().build();
-    private final TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+    private final TrafficSelector selector = DefaultTrafficSelector.emptySelector();
+    private final TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
     private final ConnectPoint cp1 = new ConnectPoint(deviceId("1"), portNumber(1));
     private final ConnectPoint cp2 = new ConnectPoint(deviceId("1"), portNumber(2));
     private final ConnectPoint cp3 = new ConnectPoint(deviceId("2"), portNumber(1));

@@ -205,8 +205,8 @@ public class KryoSerializerTest {
     @Test
     public void testFlowRuleBatchEntry() {
         final FlowRule rule1 =
-                new DefaultFlowRule(DID1, DefaultTrafficSelector.builder().build(),
-                        DefaultTrafficTreatment.builder().build(), 0, 0, 0, true);
+                new DefaultFlowRule(DID1, DefaultTrafficSelector.emptySelector(),
+                        DefaultTrafficTreatment.emptyTreatment(), 0, 0, 0, true);
         final FlowRuleBatchEntry entry1 =
                 new FlowRuleBatchEntry(FlowRuleBatchEntry.FlowRuleOperation.ADD, rule1);
         final FlowRuleBatchEntry entry2 =

@@ -67,9 +67,9 @@ public class IntentCodecTest extends AbstractIntentTest {
     private final HostId id2 = hid("12:34:56:78:92:ab/1");
     private final ApplicationId appId = new DefaultApplicationId(3, "test");
     final TrafficSelector emptySelector =
-            DefaultTrafficSelector.builder().build();
+            DefaultTrafficSelector.emptySelector();
     final TrafficTreatment emptyTreatment =
-            DefaultTrafficTreatment.builder().build();
+            DefaultTrafficTreatment.emptyTreatment();
     private final CodecContext context = new MockCodecContext();
 
     /**

@@ -312,8 +312,8 @@ public class TopologyViewMessageHandler extends TopologyViewMessageHandlerBase {
 
         HostToHostIntent intent =
                 new HostToHostIntent(appId, one, two,
-                                     DefaultTrafficSelector.builder().build(),
-                                     DefaultTrafficTreatment.builder().build());
+                                     DefaultTrafficSelector.emptySelector(),
+                                     DefaultTrafficTreatment.emptyTreatment());
 
         intentService.submit(intent);
         startMonitoringIntent(event, intent);
@@ -333,7 +333,7 @@ public class TopologyViewMessageHandler extends TopologyViewMessageHandlerBase {
         // FIXME: clearly, this is not enough
         TrafficSelector selector = DefaultTrafficSelector.builder()
                 .matchEthDst(dstHost.mac()).build();
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         MultiPointToSinglePointIntent intent =
                 new MultiPointToSinglePointIntent(appId, selector, treatment,

@@ -350,8 +350,8 @@ public class TopologyViewWebSocket
 
         HostToHostIntent intent =
                 new HostToHostIntent(appId, one, two,
-                                     DefaultTrafficSelector.builder().build(),
-                                     DefaultTrafficTreatment.builder().build());
+                                     DefaultTrafficSelector.emptySelector(),
+                                     DefaultTrafficTreatment.emptyTreatment());
 
         intentService.submit(intent);
         startMonitoringIntent(event, intent);
@@ -371,7 +371,7 @@ public class TopologyViewWebSocket
         // FIXME: clearly, this is not enough
         TrafficSelector selector = DefaultTrafficSelector.builder()
                 .matchEthDst(dstHost.mac()).build();
-        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.emptyTreatment();
 
         MultiPointToSinglePointIntent intent =
                 new MultiPointToSinglePointIntent(appId, selector, treatment,