badguardhome/internal/aghnet/ipmut.go

44 lines
988 B
Go

package aghnet
import (
"net"
"sync/atomic"
)
// IPMutFunc is the signature of a function which modifies the IP address
// instance. It should be safe for concurrent use.
type IPMutFunc func(ip net.IP)
// nopIPMutFunc is the IPMutFunc that does nothing.
func nopIPMutFunc(net.IP) {}
// IPMut is a type-safe wrapper of atomic.Value to store the IPMutFunc.
type IPMut struct {
f atomic.Value
}
// NewIPMut returns the new properly initialized *IPMut. The m is guaranteed to
// always store non-nil IPMutFunc which is safe to call.
func NewIPMut(f IPMutFunc) (m *IPMut) {
m = &IPMut{
f: atomic.Value{},
}
m.Store(f)
return m
}
// Store sets the IPMutFunc to return from Func. It's safe for concurrent use.
// If f is nil, the stored function is the no-op one.
func (m *IPMut) Store(f IPMutFunc) {
if f == nil {
f = nopIPMutFunc
}
m.f.Store(f)
}
// Load returns the previously stored IPMutFunc.
func (m *IPMut) Load() (f IPMutFunc) {
return m.f.Load().(IPMutFunc)
}