feat(events): add cursor infinite event feed

backend/jobs/tests/test_api.py

@@ -0,0 +1,43 @@
+from urllib.parse import urlparse
+
+import pytest
+from rest_framework.test import APIClient
+
+from jobs.services import create_job
+
+
+@pytest.mark.django_db
+def test_global_events_use_cursor_pagination():
+    create_job(job_type="demo.success")
+    create_job(job_type="demo.fail")
+    create_job(job_type="demo.slow")
+
+    response = APIClient().get("/api/job-events/?limit=2")
+
+    assert response.status_code == 200
+    body = response.json()
+    assert body["next"] is not None
+    assert body["previous"] is None
+    assert len(body["results"]) == 2
+    assert body["results"][0]["id"] > body["results"][1]["id"]
+
+
+@pytest.mark.django_db
+def test_global_events_next_cursor_returns_older_events():
+    create_job(job_type="demo.success")
+    create_job(job_type="demo.fail")
+    create_job(job_type="demo.slow")
+    client = APIClient()
+    first_response = client.get("/api/job-events/?limit=2")
+    first_body = first_response.json()
+    parsed_next = urlparse(first_body["next"])
+    next_path = f"{parsed_next.path}?{parsed_next.query}"
+
+    next_response = client.get(next_path)
+
+    assert next_response.status_code == 200
+    body = next_response.json()
+    assert body["next"] is None
+    assert body["previous"] is not None
+    assert len(body["results"]) == 1
+    assert body["results"][0]["id"] < first_body["results"][1]["id"]

backend/jobs/views.py

@@ -1,6 +1,7 @@
 from django.db import connection
 from rest_framework import generics, status
 from rest_framework.exceptions import NotFound, ValidationError
+from rest_framework.pagination import CursorPagination
 from rest_framework.response import Response
 from rest_framework.views import APIView
 
@@ -9,6 +10,13 @@ from jobs.serializers import JobCreateSerializer, JobEventSerializer, JobSeriali
 from jobs.services import create_job, job_stats, retry_failed_job
 
 
+class JobEventCursorPagination(CursorPagination):
+    page_size = 50
+    page_size_query_param = "limit"
+    max_page_size = 200
+    ordering = "-id"
+
+
 class HealthAPIView(APIView):
     def get(self, request):
         try:
@@ -63,21 +71,17 @@ class JobEventsAPIView(APIView):
 
 class GlobalJobEventsAPIView(APIView):
     def get(self, request):
-        queryset = JobEvent.objects.order_by("id")
-        after_id = request.query_params.get("after_id")
+        queryset = JobEvent.objects.order_by("-id")
         event_type = request.query_params.get("type")
         job_id = request.query_params.get("job_id")
-        if after_id:
-            queryset = queryset.filter(id__gt=after_id)
         if event_type:
             queryset = queryset.filter(type=event_type)
         if job_id:
             queryset = queryset.filter(job_id=job_id)
-        try:
-            limit = min(int(request.query_params.get("limit", "100")), 500)
-        except ValueError as exc:
-            raise ValidationError({"limit": "Must be an integer."}) from exc
-        return Response(JobEventSerializer(queryset[:limit], many=True).data)
+
+        paginator = JobEventCursorPagination()
+        page = paginator.paginate_queryset(queryset, request, view=self)
+        return paginator.get_paginated_response(JobEventSerializer(page, many=True).data)
 
 
 class JobStatsAPIView(APIView):