From 10d18f0788eddeaed660e437e68942d5a3a73c6b Mon Sep 17 00:00:00 2001
From: James Hinshelwood <jameshinshelwood1@gmail.com>
Date: Tue, 29 Apr 2025 17:34:09 +0100
Subject: [PATCH] Cache curl client between HTTP requests

---
 src/eval/StateIPCClient.ml | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/eval/StateIPCClient.ml b/src/eval/StateIPCClient.ml
index ccb396091..467cee32b 100644
--- a/src/eval/StateIPCClient.ml
+++ b/src/eval/StateIPCClient.ml
@@ -54,15 +54,25 @@ let ipcclient_exn_wrapper thunk =
   | e ->
       let e = Exn.to_string e in
       DebugMessage.plog (Printf.sprintf "error making JSON-RPC call: %s" e);
-      fail0 ~kind:"StateIPCClient: Unexpected error making JSON-RPC call"
+      fail0 ~kind:(Printf.sprintf "StateIPCClient: Unexpected error making JSON-RPC call: %s" e)
         ?inst:None
 
+type state = { mutable client : Ezcurl.t option };;
+let current_state = { client = None };;
+
 let http_rpc ~socket_addr (call : Rpc.call) : Rpc.response M.t =
+  let client = match current_state.client with
+    | Some c -> c
+    | None ->
+      let c = Ezcurl.make () in
+      current_state.client <- Some c;
+      c
+  in
   let msg_buf = Jsonrpc.string_of_call ~version:Jsonrpc.V2 call in
   DebugMessage.plog (Printf.sprintf "Sending: %s\n" msg_buf);
   let exception Http_error of string in
   let response =
-    match Ezcurl.post ~headers:["content-type", "application/json"] ~content:(`String msg_buf) ~params:[] ~url:socket_addr () with
+    match Ezcurl.post ~client ~headers:["content-type", "application/json"] ~content:(`String msg_buf) ~params:[] ~url:socket_addr () with
     | Ok response -> response
     | Error (_, err) -> (
       DebugMessage.plog (Printf.sprintf "error calling RPC: %s" err);