feat: add socket backlog option

src/index.ts

@@ -36,6 +36,12 @@ export interface TCPOptions {
    */
   maxConnections?: number
 
+  /**
+   * Parameter to specify the maximum length of the queue of pending connections
+   * https://nodejs.org/dist/latest-v18.x/docs/api/net.html#serverlisten
+   */
+  backlog?: number
+
   /**
    * Close server (stop listening for new connections) if connections exceed a limit.
    * Open server (start listening for new connections) if connections fall below a limit.
@@ -215,6 +221,7 @@ class TCP implements Transport {
     return new TCPListener({
       ...options,
       maxConnections: this.opts.maxConnections,
+      backlog: this.opts.backlog,
       closeServerOnMaxConnections: this.opts.closeServerOnMaxConnections,
       socketInactivityTimeout: this.opts.inboundSocketInactivityTimeout,
       socketCloseTimeout: this.opts.socketCloseTimeout,

src/listener.ts

@@ -41,6 +41,7 @@ interface Context extends TCPCreateListenerOptions {
   socketInactivityTimeout?: number
   socketCloseTimeout?: number
   maxConnections?: number
+  backlog?: number
   metrics?: Metrics
   closeServerOnMaxConnections?: CloseServerOnMaxConnectionsOpts
 }
@@ -91,6 +92,10 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
       }
     }
 
+    if (context.backlog != null && context.backlog <= 0) {
+      throw Error('backlog must be > 0')
+    }
+
     this.server
       .on('listening', () => {
         if (context.metrics != null) {
@@ -269,12 +274,14 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
 
     const peerId = ma.getPeerId()
     const listeningAddr = peerId == null ? ma.decapsulateCode(CODE_P2P) : ma
+    const netConfig = multiaddrToNetConfig(listeningAddr)
+    const { backlog } = this.context
 
     this.status = {
       started: true,
       listeningAddr,
       peerId,
-      netConfig: multiaddrToNetConfig(listeningAddr)
+      netConfig: backlog ? { ...netConfig, backlog } : netConfig
     }
 
     await this.netListen()