From 6a726a8c56b6c33f6b5cb77cedfd9a4a6ed394ad Mon Sep 17 00:00:00 2001
From: Sergey Matvienko <smatvienko@thingsboard.io>
Date: Tue, 17 Sep 2024 14:11:07 +0200
Subject: [PATCH] cache hashcode for UUIDBased and TbSubscription

---
 .../server/service/subscription/TbSubscription.java |  8 +++++++-
 .../server/common/data/id/UUIDBased.java            | 13 +++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/application/src/main/java/org/thingsboard/server/service/subscription/TbSubscription.java b/application/src/main/java/org/thingsboard/server/service/subscription/TbSubscription.java
index 4324a3514a..23b7591727 100644
--- a/application/src/main/java/org/thingsboard/server/service/subscription/TbSubscription.java
+++ b/application/src/main/java/org/thingsboard/server/service/subscription/TbSubscription.java
@@ -27,6 +27,9 @@ import java.util.function.BiConsumer;
 @AllArgsConstructor
 public abstract class TbSubscription<T> {
 
+    /** Cache the hash code */
+    private transient int hash; // Default to 0. The hash code calculated for this object likely never be zero
+
     private final String serviceId;
     private final String sessionId;
     private final int subscriptionId;
@@ -49,7 +52,10 @@ public abstract class TbSubscription<T> {
 
     @Override
     public int hashCode() {
-        return Objects.hash(sessionId, subscriptionId, tenantId, entityId, type);
+        if (hash == 0) {
+            hash = Objects.hash(sessionId, subscriptionId, tenantId, entityId, type);
+        }
+        return hash;
     }
 
 }
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/id/UUIDBased.java b/common/data/src/main/java/org/thingsboard/server/common/data/id/UUIDBased.java
index e0a1abf9ff..6cf310f7b3 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/id/UUIDBased.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/id/UUIDBased.java
@@ -25,6 +25,9 @@ public abstract class UUIDBased implements HasUUID, Serializable {
 
     private static final long serialVersionUID = 1L;
 
+    /** Cache the hash code */
+    private transient int hash; // Default to 0. The hash code calculated for this object likely never be zero
+
     private final UUID id;
 
     public UUIDBased() {
@@ -43,10 +46,12 @@ public abstract class UUIDBased implements HasUUID, Serializable {
 
     @Override
     public int hashCode() {
-        final int prime = 31;
-        int result = 1;
-        result = prime * result + ((id == null) ? 0 : id.hashCode());
-        return result;
+        if (hash == 0) {
+            final int prime = 31;
+            int result = 1;
+            hash = prime * result + ((id == null) ? 0 : id.hashCode());
+        }
+        return hash;
     }
 
     @Override