fix: Fixes the response body streaming for GetObject, implementing a chunk streamer

s3api/utils/utils.go

@@ -196,6 +196,30 @@ func SetResponseHeaders(ctx *fiber.Ctx, headers []CustomHeader) {
 	}
 }
 
+// Streams the response body by chunks
+func StreamResponseBody(ctx *fiber.Ctx, rdr io.ReadCloser) error {
+	buf := make([]byte, 4096) // 4KB chunks
+	defer rdr.Close()
+	for {
+		n, err := rdr.Read(buf)
+		if n > 0 {
+			_, writeErr := ctx.Write(buf[:n])
+			if writeErr != nil {
+				return fmt.Errorf("write chunk: %w", writeErr)
+			}
+		}
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+
+			return fmt.Errorf("read chunk: %w", err)
+		}
+	}
+
+	return nil
+}
+
 func IsValidBucketName(bucket string) bool {
 	if len(bucket) < 3 || len(bucket) > 63 {
 		return false