Redo and simplify registry and move to own package

registry/registry_handle.go

@@ -0,0 +1,37 @@
+package registry
+
+type HandleFlag byte
+
+const (
+	HandleFlag_None  HandleFlag = 0
+	HandleFlag_Alive HandleFlag = 1 << (iota - 1)
+)
+
+const (
+	GenerationShiftBits = 64 - 8
+	FlagsShiftBits      = 64 - 16
+	IndexBitMask        = 0x00_00_FFFF_FFFF_FFFF
+)
+
+// Byte 1: Generation; Byte 2: Flags; Bytes 3-8: Index
+type Handle uint64
+
+func (h Handle) HasFlag(ef HandleFlag) bool {
+	return h.Flags()&ef > 0
+}
+
+func (h Handle) Generation() byte {
+	return byte(h >> GenerationShiftBits)
+}
+
+func (h Handle) Flags() HandleFlag {
+	return HandleFlag(h >> FlagsShiftBits)
+}
+
+func (h Handle) Index() uint64 {
+	return uint64(h & IndexBitMask)
+}
+
+func NewHandle(generation byte, flags HandleFlag, index uint64) Handle {
+	return Handle(index | (uint64(generation) << GenerationShiftBits) | (uint64(flags) << FlagsShiftBits))
+}