From 942ba9f4ffc1b1ee11552717d230dfdcd953a475 Mon Sep 17 00:00:00 2001
From: Albumen Kevin <jhq0812@gmail.com>
Date: Sat, 6 Nov 2021 15:09:56 +0800
Subject: [PATCH] [3.0] Pre-allocate map size in Directory (#9222)

---
 .../registry/client/ServiceDiscoveryRegistryDirectory.java    | 4 ++--
 .../apache/dubbo/registry/integration/RegistryDirectory.java  | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistryDirectory.java b/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistryDirectory.java
index 7f10291b72f..29f07bfa0ce 100644
--- a/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistryDirectory.java
+++ b/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistryDirectory.java
@@ -40,12 +40,12 @@
 
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 import static org.apache.dubbo.common.constants.CommonConstants.DISABLED_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.ENABLED_KEY;
@@ -256,7 +256,7 @@ private void refreshInvoker(List<URL> invokerUrls) {
      * @return invokers
      */
     private Map<String, Invoker<T>> toInvokers(Map<String, Invoker<T>> oldUrlInvokerMap, List<URL> urls) {
-        Map<String, Invoker<T>> newUrlInvokerMap = new HashMap<>();
+        Map<String, Invoker<T>> newUrlInvokerMap = new ConcurrentHashMap<>(urls == null ? 1 : (int) (urls.size() / 0.75f + 1));
         if (urls == null || urls.isEmpty()) {
             return newUrlInvokerMap;
         }
diff --git a/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/RegistryDirectory.java b/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/RegistryDirectory.java
index fe0c8ee58a2..d02823b2686 100644
--- a/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/RegistryDirectory.java
+++ b/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/RegistryDirectory.java
@@ -327,7 +327,7 @@ private Optional<List<Router>> toRouters(List<URL> urls) {
      * @return invokers
      */
     private Map<URL, Invoker<T>> toInvokers(Map<URL, Invoker<T>> oldUrlInvokerMap, List<URL> urls) {
-        Map<URL, Invoker<T>> newUrlInvokerMap = new ConcurrentHashMap<>();
+        Map<URL, Invoker<T>> newUrlInvokerMap = new ConcurrentHashMap<>(urls == null ? 1 : (int) (urls.size() / 0.75f + 1));
         if (urls == null || urls.isEmpty()) {
             return newUrlInvokerMap;
         }