Clean up discrete event replaying (#26558)

sebmarkbage · web-flow · commit 9cfba0f6ecc1 · 2023-04-05T19:38:20.000-04:00
We no longer replay and discrete events.

I might re-add a form of this but it'll look a little different.
diff --git a/packages/react-dom-bindings/src/events/ReactDOMEventListener.js b/packages/react-dom-bindings/src/events/ReactDOMEventListener.js
@@ -57,7 +57,7 @@ import {isRootDehydrated} from 'react-reconciler/src/ReactFiberShellHydration';
 const {ReactCurrentBatchConfig} = ReactSharedInternals;
 
 // TODO: can we stop exporting these?
-export let _enabled: boolean = true;
+let _enabled: boolean = true;
 
 // This is exported in FB builds for use by legacy FB layer infra.
 // We'd like to remove this but it's not clear if this is safe.
diff --git a/packages/react-dom-bindings/src/events/ReactDOMEventReplaying.js b/packages/react-dom-bindings/src/events/ReactDOMEventReplaying.js
@@ -60,11 +60,6 @@ type QueuedReplayableEvent = {
 
 let hasScheduledReplayAttempt = false;
 
-// The queue of discrete events to be replayed.
-const queuedDiscreteEvents: Array<QueuedReplayableEvent> = [];
-
-// Indicates if any continuous event targets are non-null for early bailout.
-const hasAnyQueuedContinuousEvents: boolean = false;
 // The last of each continuous event type. We only need to replay the last one
 // if the last target was dehydrated.
 let queuedFocus: null | QueuedReplayableEvent = null;
@@ -82,14 +77,6 @@ type QueuedHydrationTarget = {
 };
 const queuedExplicitHydrationTargets: Array<QueuedHydrationTarget> = [];
 
-export function hasQueuedDiscreteEvents(): boolean {
-  return queuedDiscreteEvents.length > 0;
-}
-
-export function hasQueuedContinuousEvents(): boolean {
-  return hasAnyQueuedContinuousEvents;
-}
-
 const discreteReplayableEvents: Array<DOMEventName> = [
   'mousedown',
   'mouseup',
@@ -446,21 +433,6 @@ function scheduleCallbackIfUnblocked(
 export function retryIfBlockedOn(
   unblocked: Container | SuspenseInstance,
 ): void {
-  // Mark anything that was blocked on this as no longer blocked
-  // and eligible for a replay.
-  if (queuedDiscreteEvents.length > 0) {
-    scheduleCallbackIfUnblocked(queuedDiscreteEvents[0], unblocked);
-    // This is a exponential search for each boundary that commits. I think it's
-    // worth it because we expect very few discrete events to queue up and once
-    // we are actually fully unblocked it will be fast to replay them.
-    for (let i = 1; i < queuedDiscreteEvents.length; i++) {
-      const queuedEvent = queuedDiscreteEvents[i];
-      if (queuedEvent.blockedOn === unblocked) {
-        queuedEvent.blockedOn = null;
-      }
-    }
-  }
-
   if (queuedFocus !== null) {
     scheduleCallbackIfUnblocked(queuedFocus, unblocked);
   }
