fix(buffer): merge events in queue and get last screen view from buffer instead of cache

apps/worker/src/jobs/events.create-session-end.ts

@@ -79,7 +79,7 @@ export async function createSessionEnd(
   const [lastScreenView, eventsInDb] = await Promise.all([
     eventBuffer.getLastScreenView({
       projectId: payload.projectId,
-      profileId: payload.profileId || payload.deviceId,
+      sessionId: payload.sessionId,
     }),
     getCompleteSessionWithSessionStart({
       projectId: payload.projectId,

apps/worker/src/jobs/events.incoming-event.ts

@@ -7,8 +7,11 @@ import { createSessionEnd, getSessionEnd } from '@/utils/session-handler';
 import { isSameDomain, parsePath } from '@openpanel/common';
 import { parseUserAgent } from '@openpanel/common/server';
 import type { IServiceCreateEventPayload, IServiceEvent } from '@openpanel/db';
-import { checkNotificationRulesForEvent, createEvent } from '@openpanel/db';
-import { getLastScreenViewFromProfileId } from '@openpanel/db';
+import {
+  checkNotificationRulesForEvent,
+  createEvent,
+  eventBuffer,
+} from '@openpanel/db';
 import type { EventsQueuePayloadIncomingEvent } from '@openpanel/queue';
 import * as R from 'ramda';
 
@@ -106,7 +109,7 @@ export async function incomingEvent(job: Job<EventsQueuePayloadIncomingEvent>) {
   // if timestamp is from the past we dont want to create a new session
   if (uaInfo.isServer || isTimestampFromThePast) {
     const event = profileId
-      ? await getLastScreenViewFromProfileId({
+      ? await eventBuffer.getLastScreenView({
           profileId,
           projectId,
         })
@@ -124,13 +127,21 @@ export async function incomingEvent(job: Job<EventsQueuePayloadIncomingEvent>) {
     profileId,
   });
 
+  const lastScreenView = await eventBuffer.getLastScreenView({
+    projectId,
+    sessionId: sessionEnd.payload.sessionId,
+  });
+
   const payload: IServiceCreateEventPayload = merge(baseEvent, {
     deviceId: sessionEnd.payload.deviceId,
     sessionId: sessionEnd.payload.sessionId,
     referrer: sessionEnd.payload?.referrer,
     referrerName: sessionEnd.payload?.referrerName,
     referrerType: sessionEnd.payload?.referrerType,
-  }) as IServiceCreateEventPayload;
+    // if the path is not set, use the last screen view path
+    path: baseEvent.path || lastScreenView?.path || '',
+    origin: baseEvent.origin || lastScreenView?.origin || '',
+  } as Partial<IServiceCreateEventPayload>) as IServiceCreateEventPayload;
 
   if (sessionEnd.notFound) {
     await createSessionEnd({ payload });

packages/db/src/buffers/event-buffer-redis.ts

@@ -386,33 +386,10 @@ return "OK"
       timer.processSessionEvents = performance.now() - now;
       now = performance.now();
 
-      // (C) Sort events by creation time.
-      eventsToClickhouse.sort(
-        (a, b) =>
-          new Date(a.created_at || 0).getTime() -
-          new Date(b.created_at || 0).getTime(),
-      );
-
       // (B) Process no-session events
       for (const eventStr of regularQueueEvents) {
         const event = getSafeJson<IClickhouseEvent>(eventStr);
         if (event) {
-          const sessionEvents = sessions[event.session_id] || [];
-          const screenView = sessionEvents.findLast((sessionEvent) => {
-            const isScreenView = sessionEvent.name === 'screen_view';
-            const isBeforeEvent =
-              new Date(sessionEvent.created_at).getTime() <
-              new Date(event.created_at).getTime();
-
-            return isScreenView && isBeforeEvent;
-          });
-
-          if (screenView) {
-            event.path = screenView.path;
-            event.origin = screenView.origin;
-            event.properties.__inherit_from = screenView.id;
-          }
-
           eventsToClickhouse.push(event);
         }
       }
@@ -584,25 +561,45 @@ return "OK"
   }
 
   /**
-   * Retrieve the latest screen_view event for a given project/profile.
+   * Retrieve the latest screen_view event for a given project/profile or project/session
    */
   public async getLastScreenView({
     projectId,
-    profileId,
-  }: {
-    projectId: string;
-    profileId: string;
-  }): Promise<IServiceEvent | null> {
-    const redis = getRedisCache();
-    const eventStr = await redis.get(
-      this.getLastEventKey({ projectId, profileId }),
-    );
-    if (eventStr) {
-      const parsed = getSafeJson<IClickhouseEvent>(eventStr);
-      if (parsed) {
-        return transformEvent(parsed);
+    ...rest
+  }:
+    | {
+        projectId: string;
+        profileId: string;
+      }
+    | {
+        projectId: string;
+        sessionId: string;
+      }): Promise<IServiceEvent | null> {
+    if ('profileId' in rest) {
+      const redis = getRedisCache();
+      const eventStr = await redis.get(
+        this.getLastEventKey({ projectId, profileId: rest.profileId }),
+      );
+      if (eventStr) {
+        const parsed = getSafeJson<IClickhouseEvent>(eventStr);
+        if (parsed) {
+          return transformEvent(parsed);
+        }
       }
     }
+
+    if ('sessionId' in rest) {
+      const redis = getRedisCache();
+      const sessionKey = this.getSessionKey(rest.sessionId);
+      const lastEvent = await redis.lindex(sessionKey, -1);
+      if (lastEvent) {
+        const parsed = getSafeJson<IClickhouseEvent>(lastEvent);
+        if (parsed) {
+          return transformEvent(parsed);
+        }
+      }
+    }
+
     return null;
   }
 

packages/db/src/services/event.service.ts

@@ -579,35 +579,6 @@ export function getConversionEventNames(projectId: string) {
   });
 }
 
-export async function getLastScreenViewFromProfileId({
-  profileId,
-  projectId,
-}: {
-  profileId: string;
-  projectId: string;
-}) {
-  if (!profileId) {
-    return null;
-  }
-
-  const eventInBuffer = await eventBuffer.getLastScreenView({
-    projectId,
-    profileId,
-  });
-
-  if (eventInBuffer) {
-    return eventInBuffer;
-  }
-
-  const [eventInDb] = profileId
-    ? await getEvents(
-        `SELECT * FROM ${TABLE_NAMES.events} WHERE name = 'screen_view' AND profile_id = ${escape(profileId)} AND project_id = ${escape(projectId)} AND created_at >= now() - INTERVAL 30 MINUTE ORDER BY created_at DESC LIMIT 1`,
-      )
-    : [];
-
-  return eventInDb || null;
-}
-
 export async function getTopPages({
   projectId,
   cursor,