Refactor criterion codec

The previous implementation was a huge switch statement. These
changes attempt to use polymorphism to avoid all of the branching
inherent in a switch.

Change-Id: If997f028346de02b883356bcde07f62674e319be

@@ -15,6 +15,8 @@
  */
 package org.onosproject.codec.impl;
 
+import java.util.EnumMap;
+
 import org.onosproject.codec.CodecContext;
 import org.onosproject.codec.JsonCodec;
 import org.onosproject.net.flow.criteria.Criteria;
@@ -31,172 +33,295 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 public final class CriterionCodec extends JsonCodec<Criterion> {
 
-    protected static final Logger log = LoggerFactory.getLogger(CriterionCodec.class);
+    protected static final Logger log =
+            LoggerFactory.getLogger(CriterionCodec.class);
+
+    private final EnumMap<Criterion.Type, CriterionTypeFormatter> formatMap;
+
+    public CriterionCodec() {
+        formatMap = new EnumMap<>(Criterion.Type.class);
+
+        formatMap.put(Criterion.Type.IN_PORT, new FormatInPort());
+        formatMap.put(Criterion.Type.IN_PHY_PORT, new FormatInPort());
+        formatMap.put(Criterion.Type.ETH_DST, new FormatEth());
+        formatMap.put(Criterion.Type.ETH_SRC, new FormatEth());
+        formatMap.put(Criterion.Type.IP_PROTO, new FormatIpProto());
+        formatMap.put(Criterion.Type.ETH_TYPE, new FormatEthType());
+        formatMap.put(Criterion.Type.METADATA, new FormatMetadata());
+        formatMap.put(Criterion.Type.VLAN_VID, new FormatVlanVid());
+        formatMap.put(Criterion.Type.VLAN_PCP, new FormatVlanPcp());
+        formatMap.put(Criterion.Type.IP_DSCP, new FormatIpDscp());
+        formatMap.put(Criterion.Type.IP_ECN, new FormatIpEcn());
+        formatMap.put(Criterion.Type.IPV4_SRC, new FormatIp());
+        formatMap.put(Criterion.Type.IPV4_DST, new FormatIp());
+        formatMap.put(Criterion.Type.IPV6_SRC, new FormatIp());
+        formatMap.put(Criterion.Type.IPV6_DST, new FormatIp());
+        formatMap.put(Criterion.Type.TCP_SRC, new FormatTcp());
+        formatMap.put(Criterion.Type.TCP_DST, new FormatTcp());
+        formatMap.put(Criterion.Type.UDP_SRC, new FormatUdp());
+        formatMap.put(Criterion.Type.UDP_DST, new FormatUdp());
+        formatMap.put(Criterion.Type.SCTP_SRC, new FormatSctp());
+        formatMap.put(Criterion.Type.SCTP_DST, new FormatSctp());
+        formatMap.put(Criterion.Type.ICMPV4_TYPE, new FormatIcmpV4Type());
+        formatMap.put(Criterion.Type.ICMPV4_CODE, new FormatIcmpV4Code());
+        formatMap.put(Criterion.Type.IPV6_FLABEL, new FormatIpV6FLabel());
+        formatMap.put(Criterion.Type.ICMPV6_TYPE, new FormatIcmpV6Type());
+        formatMap.put(Criterion.Type.ICMPV6_CODE, new FormatIcmpV6Code());
+        formatMap.put(Criterion.Type.IPV6_ND_TARGET, new FormatV6NDTarget());
+        formatMap.put(Criterion.Type.IPV6_ND_SLL, new FormatV6NDTll());
+        formatMap.put(Criterion.Type.IPV6_ND_TLL, new FormatV6NDTll());
+        formatMap.put(Criterion.Type.MPLS_LABEL, new FormatMplsLabel());
+        formatMap.put(Criterion.Type.OCH_SIGID, new FormatOchSigId());
+        formatMap.put(Criterion.Type.OCH_SIGTYPE, new FormatOchSigType());
+        formatMap.put(Criterion.Type.MPLS_LABEL, new FormatMplsLabel());
+
+        // Currently unimplemented
+        formatMap.put(Criterion.Type.ARP_OP, new FormatUnknown());
+        formatMap.put(Criterion.Type.ARP_SHA, new FormatUnknown());
+        formatMap.put(Criterion.Type.ARP_SPA, new FormatUnknown());
+        formatMap.put(Criterion.Type.ARP_THA, new FormatUnknown());
+        formatMap.put(Criterion.Type.ARP_TPA, new FormatUnknown());
+        formatMap.put(Criterion.Type.MPLS_TC, new FormatUnknown());
+        formatMap.put(Criterion.Type.MPLS_BOS, new FormatUnknown());
+        formatMap.put(Criterion.Type.PBB_ISID, new FormatUnknown());
+        formatMap.put(Criterion.Type.PBB_UCA, new FormatUnknown());
+        formatMap.put(Criterion.Type.TUNNEL_ID, new FormatUnknown());
+        formatMap.put(Criterion.Type.IPV6_EXTHDR, new FormatUnknown());
+        formatMap.put(Criterion.Type.UNASSIGNED_40, new FormatUnknown());
+        formatMap.put(Criterion.Type.TCP_FLAGS, new FormatUnknown());
+        formatMap.put(Criterion.Type.ACTSET_OUTPUT, new FormatUnknown());
+        formatMap.put(Criterion.Type.PACKET_TYPE, new FormatUnknown());
+    }
 
-    @Override
-    public ObjectNode encode(Criterion criterion, CodecContext context) {
-        checkNotNull(criterion, "Criterion cannot be null");
+    private interface CriterionTypeFormatter {
+        ObjectNode formatCriterion(ObjectNode root, Criterion criterion);
+    }
 
-        final ObjectNode result = context.mapper().createObjectNode()
-                .put("type", criterion.type().toString());
+    private static class FormatUnknown implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            return root;
+        }
+    }
 
-        switch (criterion.type()) {
-
-            case IN_PORT:
-            case IN_PHY_PORT:
-                final Criteria.PortCriterion portCriterion = (Criteria.PortCriterion) criterion;
-                result.put("port", portCriterion.port().toLong());
-                break;
-
-            case METADATA:
-                final Criteria.MetadataCriterion metadataCriterion =
-                        (Criteria.MetadataCriterion) criterion;
-                result.put("metadata", metadataCriterion.metadata());
-                break;
-
-            case ETH_DST:
-            case ETH_SRC:
-                final Criteria.EthCriterion ethCriterion = (Criteria.EthCriterion) criterion;
-                result.put("mac", ethCriterion.mac().toString());
-                break;
-
-            case ETH_TYPE:
-                final Criteria.EthTypeCriterion ethTypeCriterion =
-                        (Criteria.EthTypeCriterion) criterion;
-                result.put("ethType", ethTypeCriterion.ethType());
-                break;
-
-            case VLAN_VID:
-                final Criteria.VlanIdCriterion vlanIdCriterion =
-                        (Criteria.VlanIdCriterion) criterion;
-                result.put("vlanId", vlanIdCriterion.vlanId().toShort());
-                break;
-
-            case VLAN_PCP:
+    private static class FormatInPort implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.PortCriterion portCriterion = (Criteria.PortCriterion) criterion;
+            return root.put("port", portCriterion.port().toLong());
+        }
+    }
+
+    private static class FormatEth implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.EthCriterion ethCriterion = (Criteria.EthCriterion) criterion;
+            return root.put("mac", ethCriterion.mac().toString());
+        }
+    }
+
+    private static class FormatIpProto implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.IPProtocolCriterion iPProtocolCriterion =
+                    (Criteria.IPProtocolCriterion) criterion;
+            return root.put("protocol", iPProtocolCriterion.protocol());
+        }
+    }
+
+    private static class FormatEthType implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.EthTypeCriterion ethTypeCriterion =
+                    (Criteria.EthTypeCriterion) criterion;
+            return root.put("ethType", ethTypeCriterion.ethType());
+        }
+    }
+
+    private static class FormatMetadata implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.MetadataCriterion metadataCriterion =
+                    (Criteria.MetadataCriterion) criterion;
+            return root.put("metadata", metadataCriterion.metadata());
+        }
+    }
+
+    private static class FormatVlanVid implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.VlanIdCriterion vlanIdCriterion =
+                    (Criteria.VlanIdCriterion) criterion;
+            return root.put("vlanId", vlanIdCriterion.vlanId().toShort());
+        }
+    }
+
+    private static class FormatVlanPcp implements CriterionTypeFormatter {
+            @Override
+            public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
                 final Criteria.VlanPcpCriterion vlanPcpCriterion =
                         (Criteria.VlanPcpCriterion) criterion;
-                result.put("priority", vlanPcpCriterion.priority());
-                break;
+                return root.put("priority", vlanPcpCriterion.priority());
+            }
+    }
 
-            case IP_DSCP:
+    private static class FormatIpDscp implements CriterionTypeFormatter {
+            @Override
+            public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
                 final Criteria.IPDscpCriterion ipDscpCriterion =
                         (Criteria.IPDscpCriterion) criterion;
-                result.put("ipDscp", ipDscpCriterion.ipDscp());
-                break;
+                return root.put("ipDscp", ipDscpCriterion.ipDscp());
+            }
+    }
 
-            case IP_ECN:
+    private static class FormatIpEcn implements CriterionTypeFormatter {
+            @Override
+            public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
                 final Criteria.IPEcnCriterion ipEcnCriterion =
                         (Criteria.IPEcnCriterion) criterion;
-                result.put("ipEcn", ipEcnCriterion.ipEcn());
-                break;
-
-            case IP_PROTO:
-                final Criteria.IPProtocolCriterion iPProtocolCriterion =
-                        (Criteria.IPProtocolCriterion) criterion;
-                result.put("protocol", iPProtocolCriterion.protocol());
-                break;
-
-            case IPV4_SRC:
-            case IPV4_DST:
-            case IPV6_SRC:
-            case IPV6_DST:
+                return root.put("ipEcn", ipEcnCriterion.ipEcn());
+            }
+    }
+
+    private static class FormatIp implements CriterionTypeFormatter {
+            @Override
+            public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
                 final Criteria.IPCriterion iPCriterion = (Criteria.IPCriterion) criterion;
-                result.put("ip", iPCriterion.ip().toString());
-                break;
+                return root.put("ip", iPCriterion.ip().toString());
+        }
+    }
 
-            case TCP_SRC:
-            case TCP_DST:
+    private static class FormatTcp implements CriterionTypeFormatter {
+            @Override
+            public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
                 final Criteria.TcpPortCriterion tcpPortCriterion =
                         (Criteria.TcpPortCriterion) criterion;
-                result.put("tcpPort", tcpPortCriterion.tcpPort().byteValue());
-                break;
+                return root.put("tcpPort", tcpPortCriterion.tcpPort().byteValue());
+            }
+    }
 
-            case UDP_SRC:
-            case UDP_DST:
+    private static class FormatUdp implements CriterionTypeFormatter {
+            @Override
+            public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
                 final Criteria.UdpPortCriterion udpPortCriterion =
                         (Criteria.UdpPortCriterion) criterion;
-                result.put("udpPort", udpPortCriterion.udpPort().byteValue());
-                break;
-
-            case SCTP_SRC:
-            case SCTP_DST:
-                final Criteria.SctpPortCriterion sctpPortCriterion =
-                        (Criteria.SctpPortCriterion) criterion;
-                result.put("sctpPort",
-                           sctpPortCriterion.sctpPort().byteValue());
-                break;
-
-            case ICMPV4_TYPE:
-                final Criteria.IcmpTypeCriterion icmpTypeCriterion =
-                        (Criteria.IcmpTypeCriterion) criterion;
-                result.put("icmpType", icmpTypeCriterion.icmpType());
-                break;
-
-            case ICMPV4_CODE:
-                final Criteria.IcmpCodeCriterion icmpCodeCriterion =
-                        (Criteria.IcmpCodeCriterion) criterion;
-                result.put("icmpCode", icmpCodeCriterion.icmpCode());
-                break;
-
-            case IPV6_FLABEL:
-                final Criteria.IPv6FlowLabelCriterion ipv6FlowLabelCriterion =
-                        (Criteria.IPv6FlowLabelCriterion) criterion;
-                result.put("flowLabel",
-                           ipv6FlowLabelCriterion.flowLabel());
-                break;
-
-            case ICMPV6_TYPE:
-                final Criteria.Icmpv6TypeCriterion icmpv6TypeCriterion =
-                        (Criteria.Icmpv6TypeCriterion) criterion;
-                result.put("icmpv6Type", icmpv6TypeCriterion.icmpv6Type());
-                break;
-
-            case ICMPV6_CODE:
-                final Criteria.Icmpv6CodeCriterion icmpv6CodeCriterion =
-                        (Criteria.Icmpv6CodeCriterion) criterion;
-                result.put("icmpv6Code", icmpv6CodeCriterion.icmpv6Code());
-                break;
-
-            case IPV6_ND_TARGET:
-                final Criteria.IPv6NDTargetAddressCriterion ipv6NDTargetAddressCriterion
-                    = (Criteria.IPv6NDTargetAddressCriterion) criterion;
-                result.put("targetAddress",
-                           ipv6NDTargetAddressCriterion.targetAddress().toString());
-                break;
-
-            case IPV6_ND_SLL:
-            case IPV6_ND_TLL:
-                final Criteria.IPv6NDLinkLayerAddressCriterion ipv6NDLinkLayerAddressCriterion
-                    = (Criteria.IPv6NDLinkLayerAddressCriterion) criterion;
-                result.put("mac",
-                           ipv6NDLinkLayerAddressCriterion.mac().toString());
-                break;
-
-            case MPLS_LABEL:
-                final Criteria.MplsCriterion mplsCriterion =
-                        (Criteria.MplsCriterion) criterion;
-                result.put("label", mplsCriterion.label());
-                break;
-
-            case OCH_SIGID:
-                final Criteria.LambdaCriterion lambdaCriterion =
-                        (Criteria.LambdaCriterion) criterion;
-                result.put("lambda", lambdaCriterion.lambda());
-                break;
-
-            case OCH_SIGTYPE:
-                final Criteria.OpticalSignalTypeCriterion opticalSignalTypeCriterion =
-                        (Criteria.OpticalSignalTypeCriterion) criterion;
-                result.put("signalType", opticalSignalTypeCriterion.signalType());
-                break;
-
-            default:
-                // Don't know how to format this type
-                log.info("Cannot convert criterion of type {} to JSON",
-                        criterion.type());
-                break;
-        }
-
-        return result;
+                return root.put("udpPort", udpPortCriterion.udpPort().byteValue());
+            }
+    }
+
+    private static class FormatSctp implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.SctpPortCriterion sctpPortCriterion =
+                    (Criteria.SctpPortCriterion) criterion;
+            return root.put("sctpPort",
+                       sctpPortCriterion.sctpPort().byteValue());
+        }
+    }
+
+    private static class FormatIcmpV4Type implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.IcmpTypeCriterion icmpTypeCriterion =
+                    (Criteria.IcmpTypeCriterion) criterion;
+            return root.put("icmpType", icmpTypeCriterion.icmpType());
+        }
+    }
+
+    private static class FormatIcmpV4Code implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.IcmpCodeCriterion icmpCodeCriterion =
+                    (Criteria.IcmpCodeCriterion) criterion;
+            return root.put("icmpCode", icmpCodeCriterion.icmpCode());
+        }
+    }
+
+    private static class FormatIpV6FLabel implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.IPv6FlowLabelCriterion ipv6FlowLabelCriterion =
+                    (Criteria.IPv6FlowLabelCriterion) criterion;
+            return root.put("flowLabel", ipv6FlowLabelCriterion.flowLabel());
+        }
+    }
+
+    private static class FormatIcmpV6Type implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.Icmpv6TypeCriterion icmpv6TypeCriterion =
+                    (Criteria.Icmpv6TypeCriterion) criterion;
+            return root.put("icmpv6Type", icmpv6TypeCriterion.icmpv6Type());
+        }
+    }
+
+    private static class FormatIcmpV6Code implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.Icmpv6CodeCriterion icmpv6CodeCriterion =
+                    (Criteria.Icmpv6CodeCriterion) criterion;
+            return root.put("icmpv6Code", icmpv6CodeCriterion.icmpv6Code());
+        }
+    }
+
+    private static class FormatV6NDTarget implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.IPv6NDTargetAddressCriterion ipv6NDTargetAddressCriterion
+                = (Criteria.IPv6NDTargetAddressCriterion) criterion;
+            return root.put("targetAddress", ipv6NDTargetAddressCriterion.targetAddress().toString());
+        }
+    }
+
+    private static class FormatV6NDTll implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.IPv6NDLinkLayerAddressCriterion ipv6NDLinkLayerAddressCriterion
+                = (Criteria.IPv6NDLinkLayerAddressCriterion) criterion;
+            return root.put("mac", ipv6NDLinkLayerAddressCriterion.mac().toString());
+        }
+    }
+
+    private static class FormatMplsLabel implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.MplsCriterion mplsCriterion =
+                    (Criteria.MplsCriterion) criterion;
+            return root.put("label", mplsCriterion.label());
+        }
+    }
+
+    private static class FormatOchSigId implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.LambdaCriterion lambdaCriterion =
+                    (Criteria.LambdaCriterion) criterion;
+            return root.put("lambda", lambdaCriterion.lambda());
+        }
+    }
+
+    private static class FormatOchSigType implements CriterionTypeFormatter {
+        @Override
+        public ObjectNode formatCriterion(ObjectNode root, Criterion criterion) {
+            final Criteria.OpticalSignalTypeCriterion opticalSignalTypeCriterion =
+                    (Criteria.OpticalSignalTypeCriterion) criterion;
+            return root.put("signalType", opticalSignalTypeCriterion.signalType());
+        }
+    }
+
+    @Override
+    public ObjectNode encode(Criterion criterion, CodecContext context) {
+        checkNotNull(criterion, "Criterion cannot be null");
+
+        final ObjectNode result = context.mapper().createObjectNode()
+                .put("type", criterion.type().toString());
+
+        CriterionTypeFormatter formatter =
+                checkNotNull(
+                        formatMap.get(criterion.type()),
+                        "No formatter found for criterion type "
+                                + criterion.type().toString());
+
+        return formatter.formatCriterion(result, criterion);
     }
 }

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.codec.impl;
+
+import java.util.EnumMap;
+
+import org.junit.Test;
+import org.onosproject.net.flow.criteria.Criterion;
+
+import static org.onlab.junit.TestUtils.getField;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+/**
+ * Unit tests for criterion codec.
+ */
+public class CriterionCodecTest {
+
+    /**
+     * Checks that all criterion types are covered by the codec.
+     */
+    @Test
+    public void checkCriterionTypes() throws Exception {
+        CriterionCodec codec = new CriterionCodec();
+        EnumMap<Criterion.Type, Object> formatMap = getField(codec, "formatMap");
+        assertThat(formatMap, notNullValue());
+
+        for (Criterion.Type type : Criterion.Type.values()) {
+            assertThat("Entry not found for " + type.toString(),
+                    formatMap.get(type), notNullValue());
+        }
+    }
+}