Re-work connections and relay stats

packages/net/src/ConnectionSender.ts

@@ -0,0 +1,53 @@
+import {Worker} from '@welshman/lib'
+import {AUTH_JOIN} from '@welshman/util'
+import {SocketStatus} from './Socket'
+import type {Message} from './Socket'
+import type {Connection} from './Connection'
+import {AuthStatus} from './ConnectionAuth'
+
+export class ConnectionSender {
+  worker: Worker<Message>
+
+  constructor(readonly cxn: Connection) {
+    this.worker = new Worker({
+      shouldDefer: ([verb, ...extra]: Message) => {
+        // If we're not connected, nothing we can do
+        if (this.cxn.socket.status !== SocketStatus.Open) return true
+
+        // Always allow sending AUTH
+        if (verb === 'AUTH') return false
+
+        // Only close reqs that have been sent
+        if (verb === 'CLOSE') return !this.cxn.state.pendingRequests.has(extra[0])
+
+        // Always allow sending join requests
+        if (verb === 'EVENT' && extra[0].kind === AUTH_JOIN) return false
+
+        // Wait for auth
+        if (![AuthStatus.None, AuthStatus.Ok].includes(this.cxn.auth.status)) return true
+
+        // Limit concurrent requests
+        if (verb === 'REQ') return this.cxn.state.pendingRequests.size >= 8
+
+        return false
+      },
+    })
+
+    this.worker.addGlobalHandler(([verb, ...extra]: Message) => {
+      // If we ended up handling a CLOSE before we handled the REQ, don't send the REQ
+      if (verb === 'CLOSE') {
+        this.worker.buffer = this.worker.buffer.filter(m => !(m[0] === 'REQ' && m[1] === extra[0]))
+      }
+
+      this.cxn.socket.send([verb, ...extra])
+    })
+  }
+
+  push = (message: Message) => {
+    this.worker.push(message)
+  }
+
+  close = async () => {
+    this.worker.pause()
+  }
+}