import related code from micro repo

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

util.go

@@ -0,0 +1,57 @@
+package grpc
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ServiceMethod converts a gRPC method to a Go method
+// Input:
+// Foo.Bar, /Foo/Bar, /package.Foo/Bar, /a.package.Foo/Bar
+// Output:
+// [Foo, Bar]
+func serviceMethod(m string) (string, string, error) {
+	if len(m) == 0 {
+		return "", "", fmt.Errorf("malformed method name: %q", m)
+	}
+
+	// grpc method
+	if m[0] == '/' {
+		// [ , Foo, Bar]
+		// [ , package.Foo, Bar]
+		// [ , a.package.Foo, Bar]
+		parts := strings.Split(m, "/")
+		if len(parts) != 3 || len(parts[1]) == 0 || len(parts[2]) == 0 {
+			return "", "", fmt.Errorf("malformed method name: %q", m)
+		}
+		service := strings.Split(parts[1], ".")
+		return service[len(service)-1], parts[2], nil
+	}
+
+	// non grpc method
+	parts := strings.Split(m, ".")
+
+	// expect [Foo, Bar]
+	if len(parts) != 2 {
+		return "", "", fmt.Errorf("malformed method name: %q", m)
+	}
+
+	return parts[0], parts[1], nil
+}
+
+// ServiceFromMethod returns the service
+// /service.Foo/Bar => service
+func serviceFromMethod(m string) string {
+	if len(m) == 0 {
+		return m
+	}
+	if m[0] != '/' {
+		return m
+	}
+	parts := strings.Split(m, "/")
+	if len(parts) < 3 {
+		return m
+	}
+	parts = strings.Split(parts[1], ".")
+	return strings.Join(parts[:len(parts)-1], ".")
+}