only prefetch if necessary

mholt · Jun 28, 2024 · 36cd8fe · 36cd8fe
1 parent 1349d38
commit 36cd8fe
Showing 1 changed file with 12 additions and 8 deletions.
diff --git a/layer4/routes.go b/layer4/routes.go
@@ -123,15 +123,19 @@ func (routes RouteList) Compile(logger *zap.Logger, matchingTimeout time.Duratio
 			return err
 		}
 		for {
-			err = cx.prefetch()
-			if err != nil {
-				logFunc := logger.Error
-				if errors.Is(err, os.ErrDeadlineExceeded) {
-					err = ErrMatchingTimeout
-					logFunc = logger.Warn
+			// only prefetch is needed, it's useful in case a RouteList in another RouteList cases
+			// if some matchers returned ErrConsumedAllPrefetchedBytes, it's true anyway
+			if len(cx.buf) == 0 || len(cx.buf) == cx.offset {
+				err = cx.prefetch()
+				if err != nil {
+					logFunc := logger.Error
+					if errors.Is(err, os.ErrDeadlineExceeded) {
+						err = ErrMatchingTimeout
+						logFunc = logger.Warn
+					}
+					logFunc("matching connection", zap.String("remote", cx.RemoteAddr().String()), zap.Error(err))
+					return nil // return nil so the error does not get logged again
 				}
-				logFunc("matching connection", zap.String("remote", cx.RemoteAddr().String()), zap.Error(err))
-				return nil // return nil so the error does not get logged again
 			}
 
 			for i, route := range routes {