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mirror of https://github.com/cwinfo/yggdrasil-go.git synced 2024-12-23 04:05:39 +00:00

only call (net.Interface).Addrs() once per minute per interface

This commit is contained in:
Arceliar 2020-05-03 02:50:04 -05:00
parent 02e1cb180d
commit de79401bb2

View File

@ -37,7 +37,12 @@ type Multicast struct {
monitor *time.Timer
platformhandler *time.Timer
_interfaces map[string]net.Interface
_interfaceAddrs map[string][]net.Addr
_interfaceAddrs map[string]addrInfo
}
type addrInfo struct {
addrs []net.Addr
time time.Time
}
type multicastInterface struct {
@ -176,7 +181,7 @@ func (m *Multicast) _monitorInterfaceChanges() {
for name, intf := range m._interfaces {
if _, ok := m.listeners[name]; !ok {
// Look up interface addresses.
addrs := m._interfaceAddrs[intf.Name]
addrs := m._interfaceAddrs[intf.Name].addrs
// Find the first link-local address.
for _, addr := range addrs {
addrIP, _, _ := net.ParseCIDR(addr.String())
@ -265,7 +270,7 @@ func (m *Multicast) _updateInterfaces() {
panic(err)
}
// Work out which interfaces to announce on
interfaceAddrs := make(map[string][]net.Addr)
interfaceAddrs := make(map[string]addrInfo)
for _, iface := range allifaces {
if iface.Flags&net.FlagUp == 0 {
// Ignore interfaces that are down
@ -279,9 +284,16 @@ func (m *Multicast) _updateInterfaces() {
// Ignore point-to-point interfaces
continue
}
addrs, _ := iface.Addrs()
var aInfo addrInfo
var isIn bool
if aInfo, isIn = m._interfaceAddrs[iface.Name]; isIn && time.Since(aInfo.time) < time.Minute {
// don't call iface.Addrs, it's unlikely things have changed
} else {
aInfo.addrs, _ = iface.Addrs()
aInfo.time = time.Now()
}
hasLLAddr := false
for _, addr := range addrs {
for _, addr := range aInfo.addrs {
addrIP, _, _ := net.ParseCIDR(addr.String())
if addrIP.To4() == nil && addrIP.IsLinkLocalUnicast() {
hasLLAddr = true
@ -301,7 +313,7 @@ func (m *Multicast) _updateInterfaces() {
// Does the interface match the regular expression? Store it if so
if e.MatchString(iface.Name) {
interfaces[iface.Name] = iface
interfaceAddrs[iface.Name] = addrs
interfaceAddrs[iface.Name] = aInfo
}
}
}