[ONOS-5945] Initial implementation of MapReferral message type

1. Add skeleton code of LispMapReferral message type
2. Refactor LispLocatorRecord and LispMapRecord

Change-Id: Icbe6243e5892a0bfb784ba3c0daa22ab73c7e977
diff --git a/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/protocols/DefaultLispReferralRecord.java b/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/protocols/DefaultLispReferralRecord.java
new file mode 100644
index 0000000..976fdd7
--- /dev/null
+++ b/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/protocols/DefaultLispReferralRecord.java
@@ -0,0 +1,207 @@
+/*
+ * Copyright 2017-present 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.lisp.msg.protocols;
+
+import com.google.common.base.Objects;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Lists;
+import io.netty.buffer.ByteBuf;
+import org.onlab.packet.DeserializationException;
+import org.onosproject.lisp.msg.exceptions.LispParseError;
+import org.onosproject.lisp.msg.exceptions.LispReaderException;
+import org.onosproject.lisp.msg.exceptions.LispWriterException;
+import org.onosproject.lisp.msg.types.LispAfiAddress;
+
+import java.util.List;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Default LISP referral record class.
+ */
+public final class DefaultLispReferralRecord extends AbstractLispRecord
+                                                implements LispReferralRecord {
+
+    private final boolean incomplete;
+    private final List<LispReferral> referrals;
+    private final List<LispSignature> signatures;
+
+    static final ReferralRecordWriter WRITER;
+    static {
+        WRITER = new ReferralRecordWriter();
+    }
+
+    /**
+     * A private constructor that protects object instantiation from external.
+     *
+     * @param recordTtl        record time-to-live value
+     * @param maskLength       mask length
+     * @param action           lisp map reply action
+     * @param authoritative    authoritative flag
+     * @param mapVersionNumber map version number
+     * @param eidPrefixAfi     EID prefix AFI address
+     * @param incomplete       incomplete flag value
+     * @param referrals        a collection referrals
+     * @param signatures       a collection signatures
+     */
+    private DefaultLispReferralRecord(int recordTtl, byte maskLength,
+                                      LispMapReplyAction action, boolean authoritative,
+                                      short mapVersionNumber, LispAfiAddress eidPrefixAfi,
+                                      boolean incomplete, List<LispReferral> referrals,
+                                      List<LispSignature> signatures) {
+        super(recordTtl, maskLength, action, authoritative, mapVersionNumber, eidPrefixAfi);
+        this.incomplete = incomplete;
+        this.referrals = referrals;
+        this.signatures = signatures;
+    }
+
+    @Override
+    public int getReferralCount() {
+        return referrals.size();
+    }
+
+    @Override
+    public int getSignatureCount() {
+        return signatures.size();
+    }
+
+    @Override
+    public boolean isIncomplete() {
+        return incomplete;
+    }
+
+    @Override
+    public List<LispReferral> getReferrals() {
+        return ImmutableList.copyOf(referrals);
+    }
+
+    @Override
+    public List<LispSignature> getSignatures() {
+        return ImmutableList.copyOf(signatures);
+    }
+
+    @Override
+    public void writeTo(ByteBuf byteBuf) throws LispWriterException {
+        WRITER.writeTo(byteBuf, this);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("record TTL", recordTtl)
+                .add("maskLength", maskLength)
+                .add("action", action)
+                .add("authoritative", authoritative)
+                .add("mapVersionNumber", mapVersionNumber)
+                .add("EID prefix AFI address", eidPrefixAfi)
+                .add("incomplete", incomplete)
+                .add("referrals", referrals)
+                .add("signatures", signatures)
+                .toString();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        DefaultLispReferralRecord that = (DefaultLispReferralRecord) o;
+        return Objects.equal(recordTtl, that.recordTtl) &&
+                Objects.equal(maskLength, that.maskLength) &&
+                Objects.equal(action, that.action) &&
+                Objects.equal(authoritative, that.authoritative) &&
+                Objects.equal(mapVersionNumber, that.mapVersionNumber) &&
+                Objects.equal(eidPrefixAfi, that.eidPrefixAfi) &&
+                Objects.equal(referrals, that.referrals) &&
+                Objects.equal(signatures, that.signatures);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(recordTtl, maskLength, action, authoritative,
+                mapVersionNumber, eidPrefixAfi, incomplete, referrals, signatures);
+    }
+
+    public static final class DefaultReferralRecordBuilder
+                                extends AbstractRecordBuilder<ReferralRecordBuilder>
+                                        implements ReferralRecordBuilder {
+
+        private boolean incomplete;
+        private List<LispReferral> referrals = Lists.newArrayList();
+        private List<LispSignature> signatures = Lists.newArrayList();
+
+        @Override
+        public ReferralRecordBuilder withReferrals(List<LispReferral> referrals) {
+            if (referrals != null) {
+                this.referrals = ImmutableList.copyOf(referrals);
+            }
+            return this;
+        }
+
+        @Override
+        public ReferralRecordBuilder withSignatures(List<LispSignature> signatures) {
+            if (signatures != null) {
+                this.signatures = ImmutableList.copyOf(signatures);
+            }
+            return this;
+        }
+
+        @Override
+        public ReferralRecordBuilder withIsIncomplete(boolean incomplete) {
+            this.incomplete = incomplete;
+            return this;
+        }
+
+        @Override
+        public LispReferralRecord build() {
+
+            checkNotNull(eidPrefixAfi, "Must specify an EID prefix");
+
+            return new DefaultLispReferralRecord(recordTtl, maskLength, action,
+                                authoritative, mapVersionNumber, eidPrefixAfi,
+                                incomplete, referrals, signatures);
+        }
+    }
+
+    public static final class ReferralRecordReader
+                                implements LispMessageReader<LispReferralRecord> {
+
+        @Override
+        public LispReferralRecord readFrom(ByteBuf byteBuf)
+                                            throws LispParseError, LispReaderException,
+                                                        DeserializationException {
+            // TODO: need to implement serialization logic
+            return null;
+        }
+    }
+
+    /**
+     * A LISP message writer for ReferralRecord portion.
+     */
+    public static final class ReferralRecordWriter
+                                implements LispMessageWriter<LispReferralRecord> {
+
+        @Override
+        public void writeTo(ByteBuf byteBuf, LispReferralRecord message)
+                                                    throws LispWriterException {
+            // TODO: need to implement serialization logic
+        }
+    }
+}