From e47e041c4b5fc95b2d845039395af132f390b6a3 Mon Sep 17 00:00:00 2001
From: Nazar Hussain <nazarhussain@gmail.com>
Date: Thu, 21 Sep 2023 12:37:44 +0200
Subject: [PATCH] Update the listner

---
 packages/transport-tcp/src/listener.ts | 75 +++++++++++++-------------
 1 file changed, 37 insertions(+), 38 deletions(-)

diff --git a/packages/transport-tcp/src/listener.ts b/packages/transport-tcp/src/listener.ts
index a92e944d77..1cae6ea50e 100644
--- a/packages/transport-tcp/src/listener.ts
+++ b/packages/transport-tcp/src/listener.ts
@@ -46,9 +46,6 @@ interface Context extends TCPCreateListenerOptions {
   closeServerOnMaxConnections?: CloseServerOnMaxConnectionsOpts
 }
 
-const SERVER_STATUS_UP = 1
-const SERVER_STATUS_DOWN = 0
-
 export interface TCPListenerMetrics {
   status: MetricGroup
   errors: CounterGroup
@@ -60,16 +57,14 @@ enum TCPListenerStatusCode {
    * When server object is initialized but we don't know the listening address yet or 
    * the server object is stopped manually, can be resumed only by calling listen()
    **/
-  INERT = 'inert',
-  /* When listener is aware of the address but the server is not started listening */
-  INITIALIZED = 'initializing',
-  LISTENING = 'listening',
+  DOWN = 0,
+  UP = 1,
   /* During the connection limits */
-  PAUSED = 'paused',
+  PAUSED = 2,
 }
 
-type Status = { code: TCPListenerStatusCode.INERT } | {
-  code: Exclude<TCPListenerStatusCode, TCPListenerStatusCode.INERT>
+type Status = { code: TCPListenerStatusCode.DOWN } | {
+  code: Exclude<TCPListenerStatusCode, TCPListenerStatusCode.DOWN>
   listeningAddr: Multiaddr
   peerId: string | null
   netConfig: NetConfig
@@ -79,7 +74,7 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
   private readonly server: net.Server
   /** Keep track of open connections to destroy in case of timeout */
   private readonly connections = new Set<MultiaddrConnection>()
-  private status: Status = { code: TCPListenerStatusCode.INERT }
+  private status: Status = { code: TCPListenerStatusCode.DOWN }
   private metrics?: TCPListenerMetrics
   private addr: string
 
@@ -146,7 +141,7 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
           }
 
           this.metrics?.status.update({
-            [this.addr]: SERVER_STATUS_UP
+            [this.addr]: TCPListenerStatusCode.UP
           })
         }
 
@@ -157,17 +152,21 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
         this.dispatchEvent(new CustomEvent<Error>('error', { detail: err }))
       })
       .on('close', () => {
-        if(this.status.code === TCPListenerStatusCode.PAUSED) return
-
         this.metrics?.status.update({
-          [this.addr]: SERVER_STATUS_DOWN
+          [this.addr]: this.status.code
         })
-        this.dispatchEvent(new CustomEvent('close'))
+
+        // If this event is emitted, the transport manager will remove the listener from it's cache
+        // in the meanwhile if the connections are dropped then listener will start listening again
+        // and the transport manager will not be able to close the server
+        if(this.status.code !== TCPListenerStatusCode.PAUSED){
+          this.dispatchEvent(new CustomEvent('close'))
+        }
       })
   }
 
   private onSocket (socket: net.Socket): void {
-    if(this.status.code === TCPListenerStatusCode.INERT) {
+    if(this.status.code === TCPListenerStatusCode.DOWN) {
       throw new Error('Server is is not listening yet')
     }
     // Avoid uncaught errors caused by unstable connections
@@ -252,7 +251,7 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
   }
 
   getAddrs (): Multiaddr[] {
-    if (this.status.code === TCPListenerStatusCode.INERT) {
+    if (this.status.code === TCPListenerStatusCode.DOWN) {
       return []
     }
 
@@ -284,7 +283,7 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
   }
 
   async listen (ma: Multiaddr): Promise<void> {
-    if (this.status.code === TCPListenerStatusCode.LISTENING || this.status.code === TCPListenerStatusCode.PAUSED ) {
+    if (this.status.code === TCPListenerStatusCode.UP || this.status.code === TCPListenerStatusCode.PAUSED ) {
       throw Error('server is already listening')
     }
 
@@ -292,14 +291,19 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
     const listeningAddr = peerId == null ? ma.decapsulateCode(CODE_P2P) : ma
     const { backlog } = this.context
 
-    this.status = {
-      code: TCPListenerStatusCode.INITIALIZED,
-      listeningAddr,
-      peerId,
-      netConfig: multiaddrToNetConfig(listeningAddr, { backlog })
+    try {
+      this.status = {
+        code: TCPListenerStatusCode.UP,
+        listeningAddr,
+        peerId,
+        netConfig: multiaddrToNetConfig(listeningAddr, { backlog })
+      }
+  
+      await this.resume()
+    } catch(err) {
+      this.status = {code: TCPListenerStatusCode.DOWN}
+      throw err
     }
-
-    await this.resume()
   }
 
   async close (): Promise<void> {
@@ -314,10 +318,7 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
    * Can resume a stopped or start an inert server
    */
   private async resume (): Promise<void> {
-    if (
-      !(this.status.code === TCPListenerStatusCode.INITIALIZED || 
-        this.status.code === TCPListenerStatusCode.PAUSED) || 
-      this.server.listening) {
+    if (this.server.listening || this.status.code === TCPListenerStatusCode.DOWN) {
       return
     }
 
@@ -328,20 +329,18 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
       this.server.once('error', reject)
       this.server.listen(netConfig, resolve)
     })
-    this.status = { ...this.status, code: TCPListenerStatusCode.LISTENING }
+
+    this.status = { ...this.status, code: TCPListenerStatusCode.UP }
     log('Listening on %s', this.server.address())
   }
 
   private async pause (permanent: boolean): Promise<void> {
-    if(this.status.code === TCPListenerStatusCode.PAUSED && permanent) {
-      this.status = { code: TCPListenerStatusCode.INERT }
+    if(!this.server.listening && this.status.code === TCPListenerStatusCode.PAUSED && permanent) {
+      this.status = { code: TCPListenerStatusCode.DOWN }
       return 
     }
 
-    if (
-      !(this.status.code === TCPListenerStatusCode.INITIALIZED || 
-        this.status.code === TCPListenerStatusCode.LISTENING) || 
-      !this.server.listening) {
+    if (!this.server.listening || this.status.code !== TCPListenerStatusCode.UP){
       return
     }
 
@@ -362,7 +361,7 @@ export class TCPListener extends EventEmitter<ListenerEvents> implements Listene
     
     // We need to set this status before closing server, so other procedures are aware
     // during the time the server is closing
-    this.status = permanent ? { code: TCPListenerStatusCode.INERT } : { ...this.status, code: TCPListenerStatusCode.PAUSED }
+    this.status = permanent ? { code: TCPListenerStatusCode.DOWN } : { ...this.status, code: TCPListenerStatusCode.PAUSED }
     await new Promise<void>((resolve, reject) => {
       this.server.close( err => { err ? reject(err) : resolve() })
     })