From 4801f21a8c5b2592f8ddd44944f4d6521ea35f35 Mon Sep 17 00:00:00 2001
From: Eoghan Murray <eoghan@getthere.ie>
Date: Thu, 15 Sep 2022 16:50:38 +0100
Subject: [PATCH 1/3] Fix that `addAction` wouldn't have any effect without a
 stop and start - noticed during live mode

---
 packages/rrweb/src/replay/timer.ts | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/packages/rrweb/src/replay/timer.ts b/packages/rrweb/src/replay/timer.ts
index 6cfa95e0d6..60689a1422 100644
--- a/packages/rrweb/src/replay/timer.ts
+++ b/packages/rrweb/src/replay/timer.ts
@@ -41,22 +41,21 @@ export class Timer {
   public start() {
     this.timeOffset = 0;
     let lastTimestamp = performance.now();
-    const { actions } = this;
     const check = () => {
       const time = performance.now();
       this.timeOffset += (time - lastTimestamp) * this.speed;
       lastTimestamp = time;
-      while (actions.length) {
-        const action = actions[0];
+      while (this.actions.length) {
+        const action = this.actions[0];
 
         if (this.timeOffset >= action.delay) {
-          actions.shift();
+          this.actions.shift();
           action.doAction();
         } else {
           break;
         }
       }
-      if (actions.length > 0 || this.liveMode) {
+      if (this.actions.length > 0 || this.liveMode) {
         this.raf = requestAnimationFrame(check);
       }
     };

From 9c570b68a784fd57a59af2ca8fec01acca4fe6f6 Mon Sep 17 00:00:00 2001
From: Eoghan Murray <eoghan@getthere.ie>
Date: Fri, 16 Sep 2022 10:44:58 +0100
Subject: [PATCH 2/3] Remove `addActions` as it has a bug-causing replacement
 of `this.actions` - refactor to reuse `addAction` and add a `push` fast-track
 to this function for the common case of adding actions in the correct order

---
 packages/rrweb/src/replay/machine.ts |  4 +---
 packages/rrweb/src/replay/timer.ts   | 14 +++++++-------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/packages/rrweb/src/replay/machine.ts b/packages/rrweb/src/replay/machine.ts
index 4409dd1151..fd4ad7bf68 100644
--- a/packages/rrweb/src/replay/machine.ts
+++ b/packages/rrweb/src/replay/machine.ts
@@ -188,7 +188,6 @@ export function createPlayerService(
           }
 
           const syncEvents = new Array<eventWithTime>();
-          const actions = new Array<actionWithDelay>();
           for (const event of neededEvents) {
             if (
               lastPlayedTimestamp &&
@@ -202,7 +201,7 @@ export function createPlayerService(
               syncEvents.push(event);
             } else {
               const castFn = getCastFn(event, false);
-              actions.push({
+              timer.addAction({
                 doAction: () => {
                   castFn();
                 },
@@ -212,7 +211,6 @@ export function createPlayerService(
           }
           applyEventsSynchronously(syncEvents);
           emitter.emit(ReplayerEvents.Flush);
-          timer.addActions(actions);
           timer.start();
         },
         pause(ctx) {
diff --git a/packages/rrweb/src/replay/timer.ts b/packages/rrweb/src/replay/timer.ts
index 60689a1422..76c08491da 100644
--- a/packages/rrweb/src/replay/timer.ts
+++ b/packages/rrweb/src/replay/timer.ts
@@ -25,18 +25,18 @@ export class Timer {
     this.liveMode = config.liveMode;
   }
   /**
-   * Add an action after the timer starts.
+   * Add an action, possibly after the timer starts.
    */
   public addAction(action: actionWithDelay) {
+    if (!this.actions.length || this.actions[this.actions.length - 1].delay <= action.delay) {
+      // 'fast track'
+      this.actions.push(action);
+      return;
+    }
+    // binary search - events can arrive out of order in a realtime context
     const index = this.findActionIndex(action);
     this.actions.splice(index, 0, action);
   }
-  /**
-   * Add all actions before the timer starts
-   */
-  public addActions(actions: actionWithDelay[]) {
-    this.actions = this.actions.concat(actions);
-  }
 
   public start() {
     this.timeOffset = 0;

From 6b41521030a998b5222a9618f1f38b8839a8dcf9 Mon Sep 17 00:00:00 2001
From: eoghanmurray <eoghanmurray@users.noreply.github.com>
Date: Thu, 22 Sep 2022 09:02:01 +0000
Subject: [PATCH 3/3] Apply formatting changes

---
 packages/rrweb/src/replay/timer.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/rrweb/src/replay/timer.ts b/packages/rrweb/src/replay/timer.ts
index 76c08491da..89d66d4bc3 100644
--- a/packages/rrweb/src/replay/timer.ts
+++ b/packages/rrweb/src/replay/timer.ts
@@ -28,7 +28,10 @@ export class Timer {
    * Add an action, possibly after the timer starts.
    */
   public addAction(action: actionWithDelay) {
-    if (!this.actions.length || this.actions[this.actions.length - 1].delay <= action.delay) {
+    if (
+      !this.actions.length ||
+      this.actions[this.actions.length - 1].delay <= action.delay
+    ) {
       // 'fast track'
       this.actions.push(action);
       return;