func (z *zeroconf) removePrinter(name string) error {
z.spMutex.Lock()
defer z.spMutex.Unlock()
r, exists := z.printers[name]
if !exists {
return fmt.Errorf("printer %s cannot be updated for Avahi publishing; it was never added", name)
}
if z.state == C.AVAHI_CLIENT_S_RUNNING && r.group != nil {
C.avahi_threaded_poll_lock(z.threadedPoll)
defer C.avahi_threaded_poll_unlock(z.threadedPoll)
var errstr *C.char
C.removeAvahiGroup(z.threadedPoll, r.group, &errstr)
if errstr != nil {
err := errors.New(C.GoString(errstr))
C.free(unsafe.Pointer(errstr))
return err
}
}
C.free(unsafe.Pointer(r.name))
delete(z.printers, name)
return nil
}
// handleClientStateChange makes clean transitions as the connection with
// avahi-daemon changes.
//export handleClientStateChange
func handleClientStateChange(client *C.AvahiClient, newState C.AvahiClientState, userdata unsafe.Pointer) {
z := instance
z.spMutex.Lock()
defer z.spMutex.Unlock()
// Name conflict.
if newState == C.AVAHI_CLIENT_S_COLLISION {
log.Warning("Avahi reports a host name collision.")
}
// Transition from not connecting to connecting. Warn in logs.
if newState == C.AVAHI_CLIENT_CONNECTING {
log.Warning("Cannot find Avahi daemon. Is it running?")
}
// Transition from running to not running. Free all groups.
if newState != C.AVAHI_CLIENT_S_RUNNING {
log.Info("Local printing disabled (Avahi client is not running).")
for name, r := range z.printers {
if r.group != nil {
if errstr := C.removeAvahiGroup(z.threadedPoll, r.group); errstr != nil {
err := errors.New(C.GoString(errstr))
log.Errorf("Failed to remove Avahi group: %s", err)
}
r.group = nil
z.printers[name] = r
}
}
}
// Transition from not running to running. Recreate all groups.
if newState == C.AVAHI_CLIENT_S_RUNNING {
log.Info("Local printing enabled (Avahi client is running).")
for name, r := range z.printers {
txt := prepareTXT(r.ty, r.url, r.id, r.online)
defer C.avahi_string_list_free(txt)
if errstr := C.addAvahiGroup(z.threadedPoll, z.client, &r.group, r.name, C.ushort(r.port), txt); errstr != nil {
err := errors.New(C.GoString(errstr))
log.Errorf("Failed to add Avahi group: %s", err)
}
z.printers[name] = r
}
}
// Transition from not failure to failure. Recreate thread poll and client.
if newState == C.AVAHI_CLIENT_FAILURE {
z.restart <- struct{}{}
}
z.state = newState
}
// handleClientStateChange makes clean transitions as the connection with
// avahi-daemon changes.
//export handleClientStateChange
func handleClientStateChange(client *C.AvahiClient, newState C.AvahiClientState, userdata unsafe.Pointer) {
z := instance
z.spMutex.Lock()
defer z.spMutex.Unlock()
// Transition from not connecting to connecting. Warn in logs.
if z.state != C.AVAHI_CLIENT_CONNECTING && newState == C.AVAHI_CLIENT_CONNECTING {
glog.Warning("Avahi client is looking for avahi-daemon. Is it running?")
}
// Transition from running to not running. Free all groups.
if z.state == C.AVAHI_CLIENT_S_RUNNING && newState != C.AVAHI_CLIENT_S_RUNNING {
glog.Info("Avahi client stopped running.")
for name, r := range z.printers {
if r.group != nil {
var errstr *C.char
C.removeAvahiGroup(z.threadedPoll, r.group, &errstr)
if errstr != nil {
fmt.Println(C.GoString(errstr))
C.free(unsafe.Pointer(errstr))
}
r.group = nil
z.printers[name] = r
}
}
}
// Transition from not running to running. Recreate all groups.
if z.state != C.AVAHI_CLIENT_S_RUNNING && newState == C.AVAHI_CLIENT_S_RUNNING {
glog.Info("Avahi client running.")
for name, r := range z.printers {
tyC := C.CString(r.ty)
defer C.free(unsafe.Pointer(tyC))
urlC := C.CString(r.url)
defer C.free(unsafe.Pointer(urlC))
idC := C.CString(r.id)
defer C.free(unsafe.Pointer(idC))
var onlineC *C.char
if r.online {
onlineC = C.CString("online")
} else {
onlineC = C.CString("offline")
}
defer C.free(unsafe.Pointer(onlineC))
var errstr *C.char
C.addAvahiGroup(z.threadedPoll, z.client, &r.group, r.name, C.ushort(r.port),
tyC, urlC, idC, onlineC, &errstr)
if errstr != nil {
err := errors.New(C.GoString(errstr))
C.free(unsafe.Pointer(errstr))
glog.Error(err)
}
z.printers[name] = r
}
}
// Transition from not failure to failure. Recreate thread poll and client.
if z.state != C.AVAHI_CLIENT_FAILURE && newState == C.AVAHI_CLIENT_FAILURE {
z.restart <- struct{}{}
}
z.state = newState
}