From 4a983eb00bc8460f7b221b35282902b83d720669 Mon Sep 17 00:00:00 2001
From: Paul D'Ambra <paul@posthog.com>
Date: Sat, 27 Jan 2024 14:07:28 +0000
Subject: [PATCH] full snapshots 5 minutes apart

---
 .../replay/sessionrecording.test.ts           | 21 ++++++++++++++++++
 src/extensions/replay/sessionrecording.ts     | 22 +++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/src/__tests__/extensions/replay/sessionrecording.test.ts b/src/__tests__/extensions/replay/sessionrecording.test.ts
index 5d6e21c8c..8ba67e05b 100644
--- a/src/__tests__/extensions/replay/sessionrecording.test.ts
+++ b/src/__tests__/extensions/replay/sessionrecording.test.ts
@@ -1484,4 +1484,25 @@ describe('SessionRecording', () => {
             expect(sessionRecording['rrwebRecord']).not.toBeUndefined()
         })
     })
+
+    describe('scheduled full snapshots', () => {
+        it('starts out unscheduled', () => {
+            expect(sessionRecording['_fullSnapshotTimer']).toBe(undefined)
+        })
+
+        it('schedules a snapshot on start', () => {
+            sessionRecording.startRecordingIfEnabled()
+            expect(sessionRecording['_fullSnapshotTimer']).not.toBe(undefined)
+        })
+
+        it('reschedules a snapshot, when we take a full snapshot', () => {
+            sessionRecording.startRecordingIfEnabled()
+            const startTimer = sessionRecording['_fullSnapshotTimer']
+
+            _emit(createFullSnapshot())
+
+            expect(sessionRecording['_fullSnapshotTimer']).not.toBe(undefined)
+            expect(sessionRecording['_fullSnapshotTimer']).not.toBe(startTimer)
+        })
+    })
 })
diff --git a/src/extensions/replay/sessionrecording.ts b/src/extensions/replay/sessionrecording.ts
index 8620bf37d..0c68ff065 100644
--- a/src/extensions/replay/sessionrecording.ts
+++ b/src/extensions/replay/sessionrecording.ts
@@ -119,6 +119,8 @@ export class SessionRecording {
     private _canvasFps: number | null = null
     private _canvasQuality: number | null = null
 
+    private _fullSnapshotTimer?: number
+
     // Util to help developers working on this feature manually override
     _forceAllowLocalhostNetworkCapture = false
 
@@ -575,6 +577,11 @@ export class SessionRecording {
                 },
             })
 
+        // rrweb takes a snapshot on initialization,
+        // but we want to take one in five minutes
+        // if nothing else happens to reset the timer
+        this._scheduleFullSnapshot()
+
         const activePlugins = this._gatherRRWebPlugins()
         this.stopRrweb = this.rrwebRecord({
             emit: (event) => {
@@ -612,6 +619,16 @@ export class SessionRecording {
         })
     }
 
+    private _scheduleFullSnapshot(): void {
+        if (this._fullSnapshotTimer) {
+            clearInterval(this._fullSnapshotTimer)
+        }
+
+        this._fullSnapshotTimer = setInterval(() => {
+            this._tryTakeFullSnapshot()
+        }, 1000 * 60 * 5) // 5 minutes
+    }
+
     private _gatherRRWebPlugins() {
         const plugins: RecordPlugin<unknown>[] = []
 
@@ -651,6 +668,11 @@ export class SessionRecording {
             rawEvent.data.href = href
         }
 
+        if (rawEvent.type === EventType.FullSnapshot) {
+            // we're processing a full snapshot, so we should reset the timer
+            this._scheduleFullSnapshot()
+        }
+
         const throttledEvent = this.mutationRateLimiter
             ? this.mutationRateLimiter.throttleMutations(rawEvent)
             : rawEvent