// NewPinger returns an object that can be pinged by calling its Ping method.
// If this method is not called frequently enough, the connection will be
// dropped.
func NewPinger(
st *state.State, resources *common.Resources, authorizer common.Authorizer,
) (
pinger, error,
) {
pingTimeout, ok := resources.Get("pingTimeout").(*pingTimeout)
if !ok {
return nullPinger{}, nil
}
return pingTimeout, nil
}
func newNotifyWatcher(st *state.State, resources *common.Resources, auth common.Authorizer, id string) (interface{}, error) {
if !isAgent(auth) {
return nil, common.ErrPerm
}
watcher, ok := resources.Get(id).(state.NotifyWatcher)
if !ok {
return nil, common.ErrUnknownWatcher
}
return &srvNotifyWatcher{
watcher: watcher,
id: id,
resources: resources,
}, nil
}
func newClientAllWatcher(st *state.State, resources *common.Resources, auth common.Authorizer, id string) (interface{}, error) {
if !auth.AuthClient() {
return nil, common.ErrPerm
}
watcher, ok := resources.Get(id).(*multiwatcher.Watcher)
if !ok {
return nil, common.ErrUnknownWatcher
}
return &srvClientAllWatcher{
watcher: watcher,
id: id,
resources: resources,
}, nil
}