Fixhancement: truncate large logs, improve auto-scroll (#11239)

src/documents/views.py

@@ -6,6 +6,7 @@ import re
 import tempfile
 import zipfile
 from collections import defaultdict
+from collections import deque
 from datetime import datetime
 from pathlib import Path
 from time import mktime
@@ -70,6 +71,7 @@ from rest_framework import parsers
 from rest_framework import serializers
 from rest_framework.decorators import action
 from rest_framework.exceptions import NotFound
+from rest_framework.exceptions import ValidationError
 from rest_framework.filters import OrderingFilter
 from rest_framework.filters import SearchFilter
 from rest_framework.generics import GenericAPIView
@@ -1363,6 +1365,13 @@ class UnifiedSearchViewSet(DocumentViewSet):
                 type=OpenApiTypes.STR,
                 location=OpenApiParameter.PATH,
             ),
+            OpenApiParameter(
+                name="limit",
+                type=OpenApiTypes.INT,
+                location=OpenApiParameter.QUERY,
+                description="Return only the last N entries from the log file",
+                required=False,
+            ),
         ],
         responses={
             (200, "application/json"): serializers.ListSerializer(
@@ -1394,8 +1403,22 @@ class LogViewSet(ViewSet):
         if not log_file.is_file():
             raise Http404
 
+        limit_param = request.query_params.get("limit")
+        if limit_param is not None:
+            try:
+                limit = int(limit_param)
+            except (TypeError, ValueError):
+                raise ValidationError({"limit": "Must be a positive integer"})
+            if limit < 1:
+                raise ValidationError({"limit": "Must be a positive integer"})
+        else:
+            limit = None
+
         with log_file.open() as f:
-            lines = [line.rstrip() for line in f.readlines()]
+            if limit is None:
+                lines = [line.rstrip() for line in f.readlines()]
+            else:
+                lines = [line.rstrip() for line in deque(f, maxlen=limit)]
 
         return Response(lines)