Prevent file not closed on error in avro checkpoint

pkg/metricstore/avroCheckpoint.go

@@ -203,6 +203,7 @@ func (l *AvroLevel) toCheckpoint(dir string, from int64, dumpAll bool) error {
 		if err != nil {
 			return fmt.Errorf("failed to open existing avro file: %v", err)
 		}
+		defer f.Close()
 
 		br := bufio.NewReader(f)
 
@@ -212,8 +213,6 @@ func (l *AvroLevel) toCheckpoint(dir string, from int64, dumpAll bool) error {
 		}
 		codec = reader.Codec()
 		schema = codec.Schema()
-
-		f.Close()
 	}
 
 	timeRef := time.Now().Add(time.Duration(-CheckpointBufferMinutes+1) * time.Minute).Unix()
@@ -249,15 +248,15 @@ func (l *AvroLevel) toCheckpoint(dir string, from int64, dumpAll bool) error {
 				return fmt.Errorf("failed to compare read and generated schema: %v", err)
 			}
 			if flag && readFlag && !errors.Is(err_, os.ErrNotExist) {
-
-				f.Close()
-
-				f, err = os.Open(filePath)
+				// Use closure to ensure file is closed even on error
+				err := func() error {
+					f2, err := os.Open(filePath)
 					if err != nil {
 						return fmt.Errorf("failed to open Avro file: %v", err)
 					}
+					defer f2.Close()
 
-				br := bufio.NewReader(f)
+					br := bufio.NewReader(f2)
 
 					ocfReader, err := goavro.NewOCFReader(br)
 					if err != nil {
@@ -273,7 +272,11 @@ func (l *AvroLevel) toCheckpoint(dir string, from int64, dumpAll bool) error {
 						recordList = append(recordList, record.(map[string]any))
 					}
 
-				f.Close()
+					return nil
+				}()
+				if err != nil {
+					return err
+				}
 
 				err = os.Remove(filePath)
 				if err != nil {
@@ -300,6 +303,7 @@ func (l *AvroLevel) toCheckpoint(dir string, from int64, dumpAll bool) error {
 	if err != nil {
 		return fmt.Errorf("failed to append new avro file: %v", err)
 	}
+	defer f.Close()
 
 	// fmt.Printf("Codec : %#v\n", codec)
 
@@ -317,8 +321,6 @@ func (l *AvroLevel) toCheckpoint(dir string, from int64, dumpAll bool) error {
 		return fmt.Errorf("failed to append record: %v", err)
 	}
 
-	f.Close()
-
 	return nil
 }