⚡ Bolt: optimize nearby issues serialization and fix cache stability

backend/routers/detection.py

@@ -3,6 +3,7 @@
 from PIL import Image
 import logging
 import time
+import hashlib
 
 from backend.utils import process_and_detect, validate_uploaded_file, process_uploaded_image
 from backend.schemas import DetectionResponse, UrgencyAnalysisRequest, UrgencyAnalysisResponse
@@ -68,35 +69,44 @@ async def _get_cached_result(key: str, func, *args, **kwargs):
     return result
 
 async def _cached_detect_severity(image_bytes: bytes):
-    key = f"severity_{hash(image_bytes)}"
+    # Stable cache key using MD5 (hash() is unstable across processes)
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"severity_{image_hash}"
     return await _get_cached_result(key, detect_severity_clip, image_bytes)
 
 async def _cached_detect_smart_scan(image_bytes: bytes):
-    key = f"smart_scan_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"smart_scan_{image_hash}"
     return await _get_cached_result(key, detect_smart_scan_clip, image_bytes)
 
 async def _cached_generate_caption(image_bytes: bytes):
-    key = f"caption_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"caption_{image_hash}"
     return await _get_cached_result(key, generate_image_caption, image_bytes)
 
 async def _cached_detect_waste(image_bytes: bytes):
-    key = f"waste_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"waste_{image_hash}"
     return await _get_cached_result(key, detect_waste_clip, image_bytes)
 
 async def _cached_detect_civic_eye(image_bytes: bytes):
-    key = f"civic_eye_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"civic_eye_{image_hash}"
     return await _get_cached_result(key, detect_civic_eye_clip, image_bytes)
 
 async def _cached_detect_graffiti(image_bytes: bytes):
-    key = f"graffiti_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"graffiti_{image_hash}"
     return await _get_cached_result(key, detect_graffiti_art_clip, image_bytes)
 
 async def _cached_detect_traffic_sign(image_bytes: bytes):
-    key = f"traffic_sign_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"traffic_sign_{image_hash}"
     return await _get_cached_result(key, detect_traffic_sign_clip, image_bytes)
 
 async def _cached_detect_abandoned_vehicle(image_bytes: bytes):
-    key = f"abandoned_vehicle_{hash(image_bytes)}"
+    image_hash = hashlib.md5(image_bytes).hexdigest()
+    key = f"abandoned_vehicle_{image_hash}"
     return await _get_cached_result(key, detect_abandoned_vehicle_clip, image_bytes)
 
 # Endpoints

backend/routers/issues.py

@@ -346,24 +346,27 @@ def get_nearby_issues(
         )
 
         # Convert to response format and limit results
-        nearby_responses = [
-            NearbyIssueResponse(
-                id=issue.id,
-                description=issue.description[:100] + "..." if len(issue.description) > 100 else issue.description,
-                category=issue.category,
-                latitude=issue.latitude,
-                longitude=issue.longitude,
-                distance_meters=distance,
-                upvotes=issue.upvotes or 0,
-                created_at=issue.created_at,
-                status=issue.status
-            )
-            for issue, distance in nearby_issues_with_distance[:limit]
-        ]
+        # Performance Boost: Map directly to dictionaries to avoid Pydantic overhead
+        nearby_data = []
+        for issue, distance in nearby_issues_with_distance[:limit]:
+            desc = issue.description or ""
+            short_desc = desc[:100] + "..." if len(desc) > 100 else desc
+
+            nearby_data.append({
+                "id": issue.id,
+                "description": short_desc,
+                "category": issue.category,
+                "latitude": issue.latitude,
+                "longitude": issue.longitude,
+                "distance_meters": distance,
+                "upvotes": issue.upvotes or 0,
+                "created_at": issue.created_at.isoformat() if issue.created_at else None,
+                "status": issue.status
+            })
 
         # Performance Boost: Cache serialized JSON to bypass redundant Pydantic validation
         # and serialization on cache hits.
-        json_data = json.dumps([r.model_dump(mode='json') for r in nearby_responses])
+        json_data = json.dumps(nearby_data)
         nearby_issues_cache.set(json_data, cache_key)
 
         return Response(content=json_data, media_type="application/json")