Optimize topology refresh

src/main/java/io/lettuce/core/cluster/PartitionsConsensusImpl.java

@@ -1,9 +1,6 @@
 package io.lettuce.core.cluster;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 import io.lettuce.core.RedisURI;
 import io.lettuce.core.cluster.models.partitions.Partitions;
@@ -31,12 +28,16 @@ Partitions getPartitions(Partitions current, Map<RedisURI, Partitions> topologyV
 
             List<VotedPartitions> votedList = new ArrayList<>();
 
+            Map<String, RedisClusterNode> nodes = new HashMap<>(current.size());
+            for (RedisClusterNode knownNode : current) {
+                nodes.put(knownNode.getNodeId(), knownNode);
+            }
+
             for (Partitions partitions : topologyViews.values()) {
 
                 int knownNodes = 0;
-                for (RedisClusterNode knownNode : current) {
-
-                    if (partitions.getPartitionByNodeId(knownNode.getNodeId()) != null) {
+                for (RedisClusterNode node : partitions) {
+                    if (nodes.containsKey(node.getNodeId())) {
                         knownNodes++;
                     }
                 }
@@ -47,6 +48,7 @@ Partitions getPartitions(Partitions current, Map<RedisURI, Partitions> topologyV
             Collections.shuffle(votedList);
             Collections.sort(votedList, (o1, o2) -> Integer.compare(o2.votes, o1.votes));
 
+            votedList.get(0).partitions.updateCache();
             return votedList.get(0).partitions;
         }
 
@@ -87,6 +89,7 @@ Partitions getPartitions(Partitions current, Map<RedisURI, Partitions> topologyV
             Collections.shuffle(votedList);
             Collections.sort(votedList, (o1, o2) -> Integer.compare(o2.votes, o1.votes));
 
+            votedList.get(0).partitions.updateCache();
             return votedList.get(0).partitions;
         }
 

src/main/java/io/lettuce/core/cluster/models/partitions/ClusterPartitionParser.java

@@ -168,11 +168,14 @@ private static RedisClusterNode parseNode(List<Object> kvlist, BitSet slots) {
      * @return the partitions object.
      */
     public static Partitions parse(String nodes) {
+        return parseByCache(nodes, true);
+    }
+
+    public static Partitions parseByCache(String nodes, boolean updateCache) {
 
         Partitions partitions = new Partitions();
 
         try {
-
             String[] lines = nodes.split(Character.toString(TOKEN_NODE_SEPARATOR));
             List<RedisClusterNode> mappedNodes = new ArrayList<>(lines.length);
 
@@ -184,7 +187,13 @@ public static Partitions parse(String nodes) {
                 }
                 mappedNodes.add(ClusterPartitionParser.parseNode(line));
             }
-            partitions.addAll(mappedNodes);
+
+            if (updateCache) {
+                partitions.addAll(mappedNodes);
+            } else {
+                partitions.addAllWithoutCache(mappedNodes);
+            }
+
         } catch (Exception e) {
             throw new RedisException("Cannot parse " + nodes, e);
         }

src/main/java/io/lettuce/core/cluster/models/partitions/Partitions.java

@@ -326,6 +326,18 @@ public boolean addAll(Collection<? extends RedisClusterNode> c) {
         }
     }
 
+    // just used in topology refresh, no race condition and lock is removed
+    public void addAllWithoutCache(Collection<? extends RedisClusterNode> c) {
+
+        LettuceAssert.noNullElements(c, "Partitions must not contain null elements");
+        partitions.addAll(c);
+        this.nodeReadView = Collections.unmodifiableCollection(c);
+    }
+
+    public void updateReadView() {
+        this.nodeReadView = Collections.unmodifiableCollection(partitions);
+    }
+
     /**
      * Remove all {@link RedisClusterNode nodes} from the {@link Partitions} using elements from the given collection and update
      * the read-view/caches.

src/main/java/io/lettuce/core/cluster/topology/DefaultClusterTopologyRefresh.java

@@ -256,7 +256,7 @@ NodeTopologyViews getNodeSpecificViews(Requests requestedTopology, Requests requ
                 allNodes.addAll(nodeWithStats);
 
                 Partitions partitions = new Partitions();
-                partitions.addAll(nodeWithStats);
+                partitions.addAllWithoutCache(nodeWithStats);
 
                 nodeTopologyView.setPartitions(partitions);
 

src/main/java/io/lettuce/core/cluster/topology/NodeTopologyView.java

@@ -73,7 +73,7 @@ private NodeTopologyView(RedisURI redisURI) {
         this.available = true;
         this.redisURI = redisURI;
 
-        this.partitions = ClusterPartitionParser.parse(clusterNodes);
+        this.partitions = ClusterPartitionParser.parseByCache(clusterNodes, false);
         this.connectedClients = getClientCount(info);
         this.replicationOffset = getReplicationOffset(info);
         this.clusterNodes = clusterNodes;
@@ -174,7 +174,7 @@ void postProcessPartitions() {
         TopologyComparators.SortAction sortAction = TopologyComparators.SortAction.getSortAction();
 
         sortAction.sort(getPartitions());
-        getPartitions().updateCache();
+        getPartitions().updateReadView();
     }
 
     public boolean canContribute() {