fix: CGO Memory leak issue (#40)

Co-authored-by: Bhargav Dodla <[email protected]>

go/internal/feast/server/http_server.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/feast-dev/feast/go/internal/feast"
 	"github.com/feast-dev/feast/go/internal/feast/model"
+	"github.com/feast-dev/feast/go/internal/feast/onlineserving"
 	"github.com/feast-dev/feast/go/internal/feast/server/logging"
 	"github.com/feast-dev/feast/go/protos/feast/serving"
 	prototypes "github.com/feast-dev/feast/go/protos/feast/types"
@@ -269,6 +270,14 @@ func (s *httpServer) getOnlineFeatures(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 	}
+
+	go releaseCGOMemory(featureVectors)
+}
+
+func releaseCGOMemory(featureVectors []*onlineserving.FeatureVector) {
+    for _, vector := range featureVectors {
+        vector.Values.Release()
+    }
 }
 
 func (s *httpServer) Serve(host string, port int) error {

go/internal/feast/transformation/transformation.go

@@ -74,6 +74,11 @@ func AugmentResponseWithOnDemandTransforms(
 			return nil, err
 		}
 		result = append(result, onDemandFeatures...)
+
+		// Release memory used by requestContextArrow
+		for _, arrowArray := range requestContextArrow {
+			arrowArray.Release()
+		}
 	}
 
 	return result, nil

sdk/python/feast/ui_server.py

@@ -53,7 +53,7 @@ def shutdown_event():
 
     ui_dir = importlib_resources.files(__name__) / "ui/build/"
     # Initialize with the projects-list.json file
-    with open(ui_dir + "projects-list.json", mode="w") as f:
+    with open(str(ui_dir) + "projects-list.json", mode="w") as f:
         projects_dict = {
             "projects": [
                 {