From 48d697eb4504b50b9dcb844ed2d9d4ec10a94a10 Mon Sep 17 00:00:00 2001
From: SylvainJuge <sylvain.juge@elastic.co>
Date: Wed, 30 Jun 2021 13:39:04 +0200
Subject: [PATCH] avoid allocation for legacy servers (#1891)

---
 .../apm/agent/report/serialize/DslJsonSerializer.java      | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/report/serialize/DslJsonSerializer.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/report/serialize/DslJsonSerializer.java
index 16c24eaa5e..8115457b90 100644
--- a/apm-agent-core/src/main/java/co/elastic/apm/agent/report/serialize/DslJsonSerializer.java
+++ b/apm-agent-core/src/main/java/co/elastic/apm/agent/report/serialize/DslJsonSerializer.java
@@ -1184,7 +1184,12 @@ private void serializeUrl(final Url url) {
             writeField("port", port);
         } else {
             // serialize as a string for compatibility
-            writeField("port", Integer.toString(port));
+            // doing it in low-level to avoid allocation
+            writeFieldName("port", jw);
+            jw.writeByte(QUOTE);
+            NumberConverter.serialize(port, jw);
+            jw.writeByte(QUOTE);
+            jw.writeByte(COMMA);
         }
         writeField("pathname", url.getPathname());
         writeField("search", url.getSearch());