Util -> Utils

1 files changed, 59 insertions, 0 deletions

diff --git a/utils/network.go b/utils/network.go
new file mode 100755
index 00000000..fcfc4ace
--- /dev/null
+++ b/utils/network.go
@@ -0,0 +1,59 @@
+// +build linux darwin freebsd
+
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strings"
+	"syscall"
+
+	"github.com/valyala/tcplisten"
+)
+
+// CreateListener crates socket listener based on DSN definition.
+func CreateListener(address string) (net.Listener, error) {
+	dsn := strings.Split(address, "://")
+	if len(dsn) != 2 {
+		return nil, errors.New("invalid DSN (tcp://:6001, unix://file.sock)")
+	}
+
+	if dsn[0] != "unix" && dsn[0] != "tcp" {
+		return nil, errors.New("invalid Protocol (tcp://:6001, unix://file.sock)")
+	}
+
+	// create unix listener
+	if dsn[0] == "unix" {
+		// check if the file exist
+		if fileExists(dsn[1]) {
+			err := syscall.Unlink(dsn[1])
+			if err != nil {
+				return nil, fmt.Errorf("error during the unlink syscall: error %v", err)
+			}
+		}
+		return net.Listen(dsn[0], dsn[1])
+	}
+
+	// configure and create tcp4 listener
+	cfg := tcplisten.Config{
+		ReusePort:   true,
+		DeferAccept: true,
+		FastOpen:    true,
+		Backlog:     0,
+	}
+
+	// only tcp4 is currently supported
+	return cfg.NewListener("tcp4", dsn[1])
+}
+
+// fileExists checks if a file exists and is not a directory before we
+// try using it to prevent further errors.
+func fileExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return !info.IsDir()
+}