Add Inner Ring code

pkg/core/container/acl/basic/util.go

@@ -0,0 +1,64 @@
+package basic
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+// Size is a size of ACL
+// in a binary form.
+const Size = 4
+
+// FromUint32 converts builtin
+// uint32 value to ACL.
+//
+// Try to avoid direct cast for
+// better portability.
+func FromUint32(v uint32) ACL {
+	return ACL(v)
+}
+
+// ToUint32 converts ACL value
+// to builtin uint32.
+//
+// Try to avoid direct cast for
+// better portability.
+func ToUint32(v ACL) uint32 {
+	return uint32(v)
+}
+
+// Equal reports whether e and e2 are the same ACL.
+//
+// Function defines the relation of equality
+// between two ACL. Try to avoid comparison through
+// "==" operator for better portability.
+func Equal(a, b ACL) bool {
+	return ToUint32(a) == ToUint32(b)
+}
+
+// Marshal encodes ACL into a
+// binary form and returns the result.
+//
+// Result slice has Size length.
+func Marshal(a ACL) []byte {
+	d := make([]byte, Size)
+
+	binary.BigEndian.PutUint32(d, ToUint32(a))
+
+	return d
+}
+
+// UnmarshalBinary unmarshals ACL from
+// a binary representation.
+//
+// If buffer size is insufficient,
+// io.ErrUnexpectedEOF is returned.
+func (a *ACL) UnmarshalBinary(data []byte) error {
+	if len(data) < Size {
+		return io.ErrUnexpectedEOF
+	}
+
+	*a = FromUint32(binary.BigEndian.Uint32(data))
+
+	return nil
+}