1 files changed, 36 insertions, 0 deletions
diff --git a/pkg/binstruct/size.go b/pkg/binstruct/size.go
new file mode 100644
index 0000000..519c2fe
--- /dev/null
+++ b/pkg/binstruct/size.go
@@ -0,0 +1,36 @@
+package binstruct
+
+import (
+	"fmt"
+	"reflect"
+)
+
+type StaticSizer interface {
+	BinaryStaticSize() int
+}
+
+func StaticSize(obj any) int {
+	return staticSize(reflect.TypeOf(obj))
+}
+
+var staticSizerType = reflect.TypeOf((*StaticSizer)(nil)).Elem()
+
+func staticSize(typ reflect.Type) int {
+	if typ.Implements(staticSizerType) {
+		return reflect.New(typ).Elem().Interface().(StaticSizer).BinaryStaticSize()
+	}
+	if szer, ok := obj.(StaticSizer); ok {
+		return szer.BinaryStaticSize()
+	}
+	switch typ.Kind() {
+	case reflect.Ptr:
+		return StaticSize(typ.Elem())
+	case reflect.Array:
+		return StaticSize(typ.Elem()) * typ.Len()
+	case reflect.Struct:
+		// TODO
+	default:
+		panic(fmt.Errorf("type=%v does not implement binfmt.StaticSizer and kind=%v is not a supported statically-sized kind",
+			typ, typ.Kind()))
+	}
+}