relay: get rid of the message queue, because js is single-threaded.

abstract-relay.ts

@@ -3,9 +3,8 @@
 import type { Event, EventTemplate, VerifiedEvent, Nostr, NostrEvent } from './core.ts'
 import { matchFilters, type Filter } from './filter.ts'
 import { getHex64, getSubscriptionId } from './fakejson.ts'
-import { Queue, normalizeURL } from './utils.ts'
+import { normalizeURL } from './utils.ts'
 import { makeAuthEvent } from './nip42.ts'
-import { yieldThread } from './helpers.ts'
 
 type RelayWebSocket = WebSocket & {
   ping?(): void
@@ -51,8 +50,6 @@ export class AbstractRelay {
   private openCountRequests = new Map<string, CountResolver>()
   private openEventPublishes = new Map<string, EventPublishResolver>()
   private ws: RelayWebSocket | undefined
-  private incomingMessageQueue = new Queue<string>()
-  private queueRunning = false
   private challenge: string | undefined
   private authPromise: Promise<string> | undefined
   private serial: number = 0
@@ -269,122 +266,6 @@ export class AbstractRelay {
     }
   }
 
-  private async runQueue() {
-    this.queueRunning = true
-    while (true) {
-      if (false === this.handleNext()) {
-        break
-      }
-      await yieldThread()
-    }
-    this.queueRunning = false
-  }
-
-  private handleNext(): undefined | false {
-    const json = this.incomingMessageQueue.dequeue()
-    if (!json) {
-      return false
-    }
-
-    // shortcut EVENT sub
-    const subid = getSubscriptionId(json)
-    if (subid) {
-      const so = this.openSubs.get(subid as string)
-      if (!so) {
-        // this is an EVENT message, but for a subscription we don't have, so just stop here
-        return
-      }
-
-      // this will be called only when this message is a EVENT message for a subscription we have
-      // we do this before parsing the JSON to not have to do that for duplicate events
-      //   since JSON parsing is slow
-      const id = getHex64(json, 'id')
-      const alreadyHave = so.alreadyHaveEvent?.(id)
-
-      // notify any interested client that the relay has this event
-      // (do this after alreadyHaveEvent() because the client may rely on this to answer that)
-      so.receivedEvent?.(this, id)
-
-      if (alreadyHave) {
-        // if we had already seen this event we can just stop here
-        return
-      }
-    }
-
-    try {
-      let data = JSON.parse(json)
-      // we won't do any checks against the data since all failures (i.e. invalid messages from relays)
-      // will naturally be caught by the encompassing try..catch block
-
-      switch (data[0]) {
-        case 'EVENT': {
-          const so = this.openSubs.get(data[1] as string) as Subscription
-          const event = data[2] as NostrEvent
-          if (this.verifyEvent(event) && matchFilters(so.filters, event)) {
-            so.onevent(event)
-          }
-          if (!so.lastEmitted || so.lastEmitted < event.created_at) so.lastEmitted = event.created_at
-          return
-        }
-        case 'COUNT': {
-          const id: string = data[1]
-          const payload = data[2] as { count: number }
-          const cr = this.openCountRequests.get(id) as CountResolver
-          if (cr) {
-            cr.resolve(payload.count)
-            this.openCountRequests.delete(id)
-          }
-          return
-        }
-        case 'EOSE': {
-          const so = this.openSubs.get(data[1] as string)
-          if (!so) return
-          so.receivedEose()
-          return
-        }
-        case 'OK': {
-          const id: string = data[1]
-          const ok: boolean = data[2]
-          const reason: string = data[3]
-          const ep = this.openEventPublishes.get(id) as EventPublishResolver
-          if (ep) {
-            clearTimeout(ep.timeout)
-            if (ok) ep.resolve(reason)
-            else ep.reject(new Error(reason))
-            this.openEventPublishes.delete(id)
-          }
-          return
-        }
-        case 'CLOSED': {
-          const id: string = data[1]
-          const so = this.openSubs.get(id)
-          if (!so) return
-          so.closed = true
-          so.close(data[2] as string)
-          return
-        }
-        case 'NOTICE': {
-          this.onnotice(data[1] as string)
-          return
-        }
-        case 'AUTH': {
-          this.challenge = data[1] as string
-          if (this.onauth) {
-            this.auth(this.onauth)
-          }
-          return
-        }
-        default: {
-          const so = this.openSubs.get(data[1])
-          so?.oncustom?.(data)
-          return
-        }
-      }
-    } catch (err) {
-      return
-    }
-  }
-
   public async send(message: string) {
     if (!this.connectionPromise) throw new SendingOnClosedConnection(message, this.url)
 
@@ -488,9 +369,109 @@ export class AbstractRelay {
   // this is the function assigned to this.ws.onmessage
   // it's exposed for testing and debugging purposes
   public _onmessage(ev: MessageEvent<any>) {
-    this.incomingMessageQueue.enqueue(ev.data as string)
+    const json = ev.data
-    if (!this.queueRunning) {
+    if (!json) {
-      this.runQueue()
+      return false
+    }
+
+    // shortcut EVENT sub
+    const subid = getSubscriptionId(json)
+    if (subid) {
+      const so = this.openSubs.get(subid as string)
+      if (!so) {
+        // this is an EVENT message, but for a subscription we don't have, so just stop here
+        return
+      }
+
+      // this will be called only when this message is a EVENT message for a subscription we have
+      // we do this before parsing the JSON to not have to do that for duplicate events
+      //   since JSON parsing is slow
+      const id = getHex64(json, 'id')
+      const alreadyHave = so.alreadyHaveEvent?.(id)
+
+      // notify any interested client that the relay has this event
+      // (do this after alreadyHaveEvent() because the client may rely on this to answer that)
+      so.receivedEvent?.(this, id)
+
+      if (alreadyHave) {
+        // if we had already seen this event we can just stop here
+        return
+      }
+    }
+
+    try {
+      let data = JSON.parse(json)
+      // we won't do any checks against the data since all failures (i.e. invalid messages from relays)
+      // will naturally be caught by the encompassing try..catch block
+
+      switch (data[0]) {
+        case 'EVENT': {
+          const so = this.openSubs.get(data[1] as string) as Subscription
+          const event = data[2] as NostrEvent
+          if (this.verifyEvent(event) && matchFilters(so.filters, event)) {
+            so.onevent(event)
+          }
+          if (!so.lastEmitted || so.lastEmitted < event.created_at) so.lastEmitted = event.created_at
+          return
+        }
+        case 'COUNT': {
+          const id: string = data[1]
+          const payload = data[2] as { count: number }
+          const cr = this.openCountRequests.get(id) as CountResolver
+          if (cr) {
+            cr.resolve(payload.count)
+            this.openCountRequests.delete(id)
+          }
+          return
+        }
+        case 'EOSE': {
+          const so = this.openSubs.get(data[1] as string)
+          if (!so) return
+          so.receivedEose()
+          return
+        }
+        case 'OK': {
+          const id: string = data[1]
+          const ok: boolean = data[2]
+          const reason: string = data[3]
+          const ep = this.openEventPublishes.get(id) as EventPublishResolver
+          if (ep) {
+            clearTimeout(ep.timeout)
+            if (ok) ep.resolve(reason)
+            else ep.reject(new Error(reason))
+            this.openEventPublishes.delete(id)
+          }
+          return
+        }
+        case 'CLOSED': {
+          const id: string = data[1]
+          const so = this.openSubs.get(id)
+          if (!so) return
+          so.closed = true
+          so.close(data[2] as string)
+          return
+        }
+        case 'NOTICE': {
+          this.onnotice(data[1] as string)
+          return
+        }
+        case 'AUTH': {
+          this.challenge = data[1] as string
+          if (this.onauth) {
+            this.auth(this.onauth)
+          }
+          return
+        }
+        default: {
+          const so = this.openSubs.get(data[1])
+          so?.oncustom?.(data)
+          return
+        }
+      }
+    } catch (err) {
+      const [_, __, event] = JSON.parse(json)
+      ;(window as any).printer.maybe(event.pubkey, ':: caught err', event, this.url, err)
+      return
     }
   }
 }

helpers.ts

@@ -1,37 +1,5 @@
 import { verifiedSymbol, type Event, type Nostr, VerifiedEvent } from './core.ts'
 
-export async function yieldThread() {
-  return new Promise<void>((resolve, reject) => {
-    try {
-      // Check if MessageChannel is available
-      if (typeof MessageChannel !== 'undefined') {
-        const ch = new MessageChannel()
-        const handler = () => {
-          // @ts-ignore (typescript thinks this property should be called `removeListener`, but in fact it's `removeEventListener`)
-          ch.port1.removeEventListener('message', handler)
-          resolve()
-        }
-        // @ts-ignore (typescript thinks this property should be called `addListener`, but in fact it's `addEventListener`)
-        ch.port1.addEventListener('message', handler)
-        ch.port2.postMessage(0)
-        ch.port1.start()
-      } else {
-        if (typeof setImmediate !== 'undefined') {
-          setImmediate(resolve)
-        } else if (typeof setTimeout !== 'undefined') {
-          setTimeout(resolve, 0)
-        } else {
-          // Last resort - resolve immediately
-          resolve()
-        }
-      }
-    } catch (e) {
-      console.error('during yield: ', e)
-      reject(e)
-    }
-  })
-}
-
 export const alwaysTrue: Nostr['verifyEvent'] = (t: Event): t is VerifiedEvent => {
   t[verifiedSymbol] = true
   return true

utils.ts

@@ -123,62 +123,3 @@ export function mergeReverseSortedLists(list1: NostrEvent[], list2: NostrEvent[]
 
   return result
 }
-
-export class QueueNode<V> {
-  public value: V
-  public next: QueueNode<V> | null = null
-  public prev: QueueNode<V> | null = null
-
-  constructor(message: V) {
-    this.value = message
-  }
-}
-
-export class Queue<V> {
-  public first: QueueNode<V> | null
-  public last: QueueNode<V> | null
-
-  constructor() {
-    this.first = null
-    this.last = null
-  }
-
-  enqueue(value: V): boolean {
-    const newNode = new QueueNode(value)
-    if (!this.last) {
-      // list is empty
-      this.first = newNode
-      this.last = newNode
-    } else if (this.last === this.first) {
-      // list has a single element
-      this.last = newNode
-      this.last.prev = this.first
-      this.first.next = newNode
-    } else {
-      // list has elements, add as last
-      newNode.prev = this.last
-      this.last.next = newNode
-      this.last = newNode
-    }
-    return true
-  }
-
-  dequeue(): V | null {
-    if (!this.first) return null
-
-    if (this.first === this.last) {
-      const target = this.first
-      this.first = null
-      this.last = null
-      return target.value
-    }
-
-    const target = this.first
-    this.first = target.next
-    if (this.first) {
-      this.first.prev = null // fix: clean up prev pointer
-    }
-
-    return target.value
-  }
-}