package journal

// Attr represents a key/value pair ("attribute"), several of which comprise a
// journal entry.
type Attr struct {
	Key   AttrKey
	Value []byte
}

// UseTextProto returns true if we can use the text protocol to encode the
// message on the wire. It is heuristic; it will only consider messages of
// ≤ 128 bytes. Following guidance at https://systemd.io/JOURNAL_NATIVE_PROTOCOL/
// it is intended to make for nice strace(1) traces.
func (a Attr) UseTextProto() bool {
	if len(a.Value) > 128 {
		return false
	}
	for _, b := range a.Value {
		if b < 32 || b > 0xFE {
			return false
		}
	}
	return true
}

// StringAttr captures the common paradigm of building an Attr from a string.
func StringAttr(key AttrKey, value string) Attr {
	return Attr{
		Key:   key,
		Value: []byte(value),
	}
}