From 131248c257cadb68bd5192ebd5d4ddc3dbdab9b0 Mon Sep 17 00:00:00 2001
From: Ben Adams <thundercat@illyriad.co.uk>
Date: Thu, 21 Nov 2024 12:31:38 +0000
Subject: [PATCH] Switch off Response Compression for loopback

---
 .../Nethermind.Runner/JsonRpc/Startup.cs          | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/Nethermind/Nethermind.Runner/JsonRpc/Startup.cs b/src/Nethermind/Nethermind.Runner/JsonRpc/Startup.cs
index 351a301f935..5eb8d057040 100644
--- a/src/Nethermind/Nethermind.Runner/JsonRpc/Startup.cs
+++ b/src/Nethermind/Nethermind.Runner/JsonRpc/Startup.cs
@@ -6,6 +6,7 @@
 using System.Diagnostics;
 using System.IO;
 using System.IO.Pipelines;
+using System.Net;
 using System.Security.Authentication;
 using System.Threading;
 using System.Threading.Tasks;
@@ -82,7 +83,6 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IJsonRpc
 
         app.UseRouting();
         app.UseCors();
-        app.UseResponseCompression();
 
         IConfigProvider? configProvider = app.ApplicationServices.GetService<IConfigProvider>();
         IRpcAuthentication? rpcAuthentication = app.ApplicationServices.GetService<IRpcAuthentication>();
@@ -99,6 +99,12 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IJsonRpc
         IJsonRpcUrlCollection jsonRpcUrlCollection = app.ApplicationServices.GetRequiredService<IJsonRpcUrlCollection>();
         IHealthChecksConfig healthChecksConfig = configProvider.GetConfig<IHealthChecksConfig>();
 
+        // If request is local, don't use response compression,
+        // as it allocates a lot, but doesn't improve much for loopback
+        app.UseWhen(ctx =>
+            !IsLocalhost(ctx.Connection.RemoteIpAddress),
+            builder => builder.UseResponseCompression());
+
         if (initConfig.WebSocketsEnabled)
         {
             app.UseWebSockets(new WebSocketOptions());
@@ -285,6 +291,13 @@ async Task PushErrorResponse(int statusCode, int errorCode, string message)
         });
     }
 
+    /// <summary>
+    /// Check for IPv4 localhost (127.0.0.1) and IPv6 localhost (::1) 
+    /// </summary>
+    /// <param name="remoteIp">Request source</param>
+    private static bool IsLocalhost(IPAddress remoteIp)
+        => IPAddress.IsLoopback(remoteIp) || remoteIp.Equals(IPAddress.IPv6Loopback);
+
     private static int GetStatusCode(JsonRpcResult result)
     {
         if (result.IsCollection)