Consolidating the Core and Replica topology differences into one happ…

…y shared difference

enterprise/causal-clustering/src/main/java/org/neo4j/causalclustering/discovery/CoreTopology.java

@@ -72,78 +72,23 @@ public String toString()
         return format( "{clusterId=%s, bootstrappable=%s, coreMembers=%s}", clusterId, canBeBootstrapped(), coreMembers );
     }
 
-    CoreTopologyDifference difference( CoreTopology other )
+    TopologyDifference difference( CoreTopology other )
     {
         Set<MemberId> members = coreMembers.keySet();
         Set<MemberId> otherMembers = other.coreMembers.keySet();
 
         Set<Difference> added = otherMembers.stream().filter( m -> !members.contains( m ) )
-                .map( memberId -> asDifference( other, memberId ) ).collect( toSet() );
+                .map( memberId -> Difference.asDifference( other, memberId ) ).collect( toSet() );
 
         Set<Difference> removed = members.stream().filter( m -> !otherMembers.contains( m ) )
-                .map( memberId -> asDifference( CoreTopology.this, memberId ) ).collect( toSet() );
+                .map( memberId -> Difference.asDifference( CoreTopology.this, memberId ) ).collect( toSet() );
 
-        return new CoreTopologyDifference( added, removed );
-    }
-
-    private Difference asDifference( CoreTopology topology, MemberId memberId )
-    {
-        return new Difference( memberId, topology.find( memberId ).orElse( null ) );
+        return new TopologyDifference( added, removed );
     }
 
     public Optional<MemberId> anyCoreMemberId()
     {
             return coreMembers.keySet().stream().findAny();
     }
 
-    class CoreTopologyDifference
-    {
-        private Set<Difference> added;
-        private Set<Difference> removed;
-
-        CoreTopologyDifference( Set<Difference> added, Set<Difference> removed )
-        {
-            this.added = added;
-            this.removed = removed;
-        }
-
-        Set<Difference> added()
-        {
-            return added;
-        }
-
-        Set<Difference> removed()
-        {
-            return removed;
-        }
-
-        boolean hasChanges()
-        {
-            return added.size() > 0 || removed.size() > 0;
-        }
-
-        @Override
-        public String toString()
-        {
-            return String.format( "{added=%s, removed=%s}", added, removed );
-        }
-    }
-
-    private class Difference
-    {
-        private MemberId memberId;
-        private CoreServerInfo coreServerInfo;
-
-        Difference( MemberId memberId, CoreServerInfo coreServerInfo )
-        {
-            this.memberId = memberId;
-            this.coreServerInfo = coreServerInfo;
-        }
-
-        @Override
-        public String toString()
-        {
-            return String.format( "{memberId=%s, coreServerInfo=%s}", memberId, coreServerInfo );
-        }
-    }
 }

enterprise/causal-clustering/src/main/java/org/neo4j/causalclustering/discovery/Difference.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.causalclustering.discovery;
+
+import org.neo4j.causalclustering.identity.MemberId;
+
+class Difference
+{
+    private MemberId memberId;
+    private CatchupServerAddress server;
+
+    private Difference( MemberId memberId, CatchupServerAddress server )
+    {
+        this.memberId = memberId;
+        this.server = server;
+    }
+
+    static Difference asDifference( CoreTopology topology, MemberId memberId )
+    {
+        return new Difference( memberId, topology.find( memberId ).orElse( null ) );
+    }
+
+    static Difference asDifference( ReadReplicaTopology topology, MemberId memberId )
+    {
+        return new Difference( memberId, topology.find( memberId ).orElse( null ) );
+    }
+
+    @Override
+    public String toString()
+    {
+        return String.format( "{memberId=%s, info=%s}", memberId, server );
+    }
+}

enterprise/causal-clustering/src/main/java/org/neo4j/causalclustering/discovery/HazelcastCoreTopologyService.java

@@ -253,7 +253,7 @@ private void refreshCoreTopology()
     {
         CoreTopology newCoreTopology = getCoreTopology( hazelcastInstance, config, log );
 
-        CoreTopology.CoreTopologyDifference difference = coreTopology.difference( newCoreTopology );
+        TopologyDifference difference = coreTopology.difference( newCoreTopology );
         if ( difference.hasChanges() )
         {
             log.info( "Core topology changed %s", difference );
@@ -267,7 +267,7 @@ private void refreshReadReplicaTopology()
     {
         ReadReplicaTopology newReadReplicaTopology = getReadReplicaTopology( hazelcastInstance, log );
 
-        ReadReplicaTopology.ReadReplicaTopologyDifference difference = readReplicaTopology.difference( newReadReplicaTopology );
+        TopologyDifference difference = readReplicaTopology.difference( newReadReplicaTopology );
         if ( difference.hasChanges() )
         {
             log.info( "Read replica topology changed %s", difference );

enterprise/causal-clustering/src/main/java/org/neo4j/causalclustering/discovery/ReadReplicaTopology.java

@@ -29,6 +29,8 @@
 import static java.util.Collections.emptyMap;
 import static java.util.stream.Collectors.toSet;
 
+import static org.neo4j.causalclustering.discovery.Difference.asDifference;
+
 
 public class ReadReplicaTopology
 {
@@ -74,73 +76,17 @@ public Optional<MemberId> anyReadReplicaMemberId()
         }
     }
 
-    ReadReplicaTopologyDifference difference( ReadReplicaTopology other )
+    TopologyDifference difference( ReadReplicaTopology other )
     {
         Set<MemberId> members = readReplicaMembers.keySet();
         Set<MemberId> otherMembers = other.readReplicaMembers.keySet();
 
-        Set<ReadReplicaTopology.Difference> added = otherMembers.stream().filter( m -> !members.contains( m ) )
+        Set<Difference> added = otherMembers.stream().filter( m -> !members.contains( m ) )
                 .map( memberId -> asDifference( other, memberId ) ).collect( toSet() );
 
-        Set<ReadReplicaTopology.Difference> removed = members.stream().filter( m -> !otherMembers.contains( m ) )
+        Set<Difference> removed = members.stream().filter( m -> !otherMembers.contains( m ) )
                 .map( memberId -> asDifference( ReadReplicaTopology.this, memberId ) ).collect( toSet() );
 
-        return new ReadReplicaTopologyDifference( added, removed );
-    }
-
-    private ReadReplicaTopology.Difference asDifference( ReadReplicaTopology topology, MemberId memberId )
-    {
-        return new ReadReplicaTopology.Difference( memberId, topology.find( memberId ).orElse( null ) );
-    }
-
-    class ReadReplicaTopologyDifference
-    {
-        private Set<ReadReplicaTopology.Difference> added;
-        private Set<ReadReplicaTopology.Difference> removed;
-
-        ReadReplicaTopologyDifference( Set<ReadReplicaTopology.Difference> added, Set<ReadReplicaTopology.Difference> removed )
-        {
-            this.added = added;
-            this.removed = removed;
-        }
-
-        Set<ReadReplicaTopology.Difference> added()
-        {
-            return added;
-        }
-
-        Set<ReadReplicaTopology.Difference> removed()
-        {
-            return removed;
-        }
-
-        boolean hasChanges()
-        {
-            return added.size() > 0 || removed.size() > 0;
-        }
-
-        @Override
-        public String toString()
-        {
-            return String.format( "{added=%s, removed=%s}", added, removed );
-        }
-    }
-
-    private class Difference
-    {
-        private MemberId memberId;
-        private ReadReplicaInfo readReplicaInfo;
-
-        Difference( MemberId memberId, ReadReplicaInfo readReplicaInfo )
-        {
-            this.memberId = memberId;
-            this.readReplicaInfo = readReplicaInfo;
-        }
-
-        @Override
-        public String toString()
-        {
-            return String.format( "{memberId=%s, readReplicaInfo=%s}", memberId, readReplicaInfo );
-        }
+        return new TopologyDifference( added, removed );
     }
 }

enterprise/causal-clustering/src/main/java/org/neo4j/causalclustering/discovery/TopologyDifference.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.causalclustering.discovery;
+
+import java.util.Set;
+
+class TopologyDifference
+{
+    private Set<Difference> added;
+    private Set<Difference> removed;
+
+    TopologyDifference( Set<Difference> added, Set<Difference> removed )
+    {
+        this.added = added;
+        this.removed = removed;
+    }
+
+    Set<Difference> added()
+    {
+        return added;
+    }
+
+    Set<Difference> removed()
+    {
+        return removed;
+    }
+
+    boolean hasChanges()
+    {
+        return added.size() > 0 || removed.size() > 0;
+    }
+
+    @Override
+    public String toString()
+    {
+        return String.format( "{added=%s, removed=%s}", added, removed );
+    }
+}

enterprise/causal-clustering/src/test/java/org/neo4j/causalclustering/discovery/CoreTopologyTest.java

@@ -48,7 +48,7 @@ public void identicalTopologiesShouldHaveNoDifference() throws Exception
         CoreTopology topology = new CoreTopology( new ClusterId( UUID.randomUUID() ), true, coreMembers );
 
         // when
-        CoreTopology.CoreTopologyDifference diff =  topology.difference(topology);
+        TopologyDifference diff =  topology.difference(topology);
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 0 ) );
@@ -74,7 +74,7 @@ public void shouldDetectAddedMembers() throws Exception
         CoreTopology topology = new CoreTopology( new ClusterId( UUID.randomUUID() ), true, initialMembers );
 
         // when
-        CoreTopology.CoreTopologyDifference diff =  topology.difference(new CoreTopology( new ClusterId( UUID.randomUUID() ), true, newMembers ));
+        TopologyDifference diff =  topology.difference(new CoreTopology( new ClusterId( UUID.randomUUID() ), true, newMembers ));
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 1 ) );
@@ -98,7 +98,7 @@ public void shouldDetectRemovedMembers() throws Exception
         CoreTopology topology = new CoreTopology( new ClusterId( UUID.randomUUID() ), true, initialMembers );
 
         // when
-        CoreTopology.CoreTopologyDifference diff =  topology.difference(new CoreTopology( new ClusterId( UUID.randomUUID() ), true, newMembers ));
+        TopologyDifference diff =  topology.difference(new CoreTopology( new ClusterId( UUID.randomUUID() ), true, newMembers ));
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 0 ) );
@@ -121,7 +121,7 @@ public void shouldDetectAddedAndRemovedMembers() throws Exception
         CoreTopology topology = new CoreTopology( new ClusterId( UUID.randomUUID() ), true, initialMembers );
 
         // when
-        CoreTopology.CoreTopologyDifference diff =  topology.difference(new CoreTopology( new ClusterId( UUID.randomUUID() ), true, newMembers ));
+        TopologyDifference diff =  topology.difference(new CoreTopology( new ClusterId( UUID.randomUUID() ), true, newMembers ));
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 2 ) );

enterprise/causal-clustering/src/test/java/org/neo4j/causalclustering/discovery/ReadReplicaTopologyTest.java

@@ -26,7 +26,6 @@
 import org.hamcrest.Matchers;
 import org.junit.Test;
 
-import org.neo4j.causalclustering.identity.ClusterId;
 import org.neo4j.causalclustering.identity.MemberId;
 
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -48,7 +47,7 @@ public void identicalTopologiesShouldHaveNoDifference() throws Exception
         ReadReplicaTopology topology = new ReadReplicaTopology( readReplicaMembers );
 
         // when
-        ReadReplicaTopology.ReadReplicaTopologyDifference diff =  topology.difference(topology);
+        TopologyDifference diff =  topology.difference(topology);
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 0 ) );
@@ -74,7 +73,7 @@ public void shouldDetectAddedMembers() throws Exception
         ReadReplicaTopology topology = new ReadReplicaTopology( initialMembers );
 
         // when
-        ReadReplicaTopology.ReadReplicaTopologyDifference diff =  topology.difference(new ReadReplicaTopology( newMembers ));
+        TopologyDifference diff =  topology.difference(new ReadReplicaTopology( newMembers ));
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 1 ) );
@@ -98,7 +97,7 @@ public void shouldDetectRemovedMembers() throws Exception
         ReadReplicaTopology topology = new ReadReplicaTopology( initialMembers );
 
         // when
-        ReadReplicaTopology.ReadReplicaTopologyDifference diff =  topology.difference(new ReadReplicaTopology( newMembers ));
+        TopologyDifference diff =  topology.difference(new ReadReplicaTopology( newMembers ));
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 0 ) );
@@ -121,7 +120,7 @@ public void shouldDetectAddedAndRemovedMembers() throws Exception
         ReadReplicaTopology topology = new ReadReplicaTopology( initialMembers );
 
         // when
-        ReadReplicaTopology.ReadReplicaTopologyDifference diff =  topology.difference(new ReadReplicaTopology( newMembers ));
+        TopologyDifference diff =  topology.difference(new ReadReplicaTopology( newMembers ));
 
         // then
         assertThat( diff.added().size(), Matchers.equalTo( 2 ) );