Improve async cluster connection initialization

Author: gerzse

redis/asyncio/cluster.py

@@ -1317,37 +1317,35 @@ async def initialize(self) -> None:
                 port = int(primary_node[1])
                 host, port = self.remap_host_port(host, port)
 
+                nodes_for_slot = []
+
                 target_node = tmp_nodes_cache.get(get_node_name(host, port))
                 if not target_node:
                     target_node = ClusterNode(
                         host, port, PRIMARY, **self.connection_kwargs
                     )
                 # add this node to the nodes cache
                 tmp_nodes_cache[target_node.name] = target_node
+                nodes_for_slot.append(target_node)
+
+                replica_nodes = [slot[j] for j in range(3, len(slot))]
+                for replica_node in replica_nodes:
+                    host = replica_node[0]
+                    port = replica_node[1]
+                    host, port = self.remap_host_port(host, port)
+
+                    target_replica_node = tmp_nodes_cache.get(get_node_name(host, port))
+                    if not target_replica_node:
+                        target_replica_node = ClusterNode(
+                            host, port, REPLICA, **self.connection_kwargs
+                        )
+                    nodes_for_slot.append(target_replica_node)
+                    # add this node to the nodes cache
+                    tmp_nodes_cache[target_replica_node.name] = target_replica_node
 
                 for i in range(int(slot[0]), int(slot[1]) + 1):
                     if i not in tmp_slots:
-                        tmp_slots[i] = []
-                        tmp_slots[i].append(target_node)
-                        replica_nodes = [slot[j] for j in range(3, len(slot))]
-
-                        for replica_node in replica_nodes:
-                            host = replica_node[0]
-                            port = replica_node[1]
-                            host, port = self.remap_host_port(host, port)
-
-                            target_replica_node = tmp_nodes_cache.get(
-                                get_node_name(host, port)
-                            )
-                            if not target_replica_node:
-                                target_replica_node = ClusterNode(
-                                    host, port, REPLICA, **self.connection_kwargs
-                                )
-                            tmp_slots[i].append(target_replica_node)
-                            # add this node to the nodes cache
-                            tmp_nodes_cache[target_replica_node.name] = (
-                                target_replica_node
-                            )
+                        tmp_slots[i] = nodes_for_slot
                     else:
                         # Validate that 2 nodes want to use the same slot cache
                         # setup