kubernetes/vendor/github.com/coreos/go-systemd/v22/dbus/subscription.go

const cleanIgnoreInterval …

const ignoreInterval …

// Subscribe sets up this connection to subscribe to all systemd dbus events.
// This is required before calling SubscribeUnits. When the connection closes
// systemd will automatically stop sending signals so there is no need to
// explicitly call Unsubscribe().
func (c *Conn) Subscribe() error { … }

// Unsubscribe this connection from systemd dbus events.
func (c *Conn) Unsubscribe() error { … }

func (c *Conn) dispatch() { … }

// SubscribeUnits returns two unbuffered channels which will receive all changed units every
// interval.  Deleted units are sent as nil.
func (c *Conn) SubscribeUnits(interval time.Duration) (<-chan map[string]*UnitStatus, <-chan error) { … }

// SubscribeUnitsCustom is like SubscribeUnits but lets you specify the buffer
// size of the channels, the comparison function for detecting changes and a filter
// function for cutting down on the noise that your channel receives.
func (c *Conn) SubscribeUnitsCustom(interval time.Duration, buffer int, isChanged func(*UnitStatus, *UnitStatus) bool, filterUnit func(string) bool) (<-chan map[string]*UnitStatus, <-chan error) { … }

type SubStateUpdate …

// SetSubStateSubscriber writes to updateCh when any unit's substate changes.
// Although this writes to updateCh on every state change, the reported state
// may be more recent than the change that generated it (due to an unavoidable
// race in the systemd dbus interface).  That is, this method provides a good
// way to keep a current view of all units' states, but is not guaranteed to
// show every state transition they go through.  Furthermore, state changes
// will only be written to the channel with non-blocking writes.  If updateCh
// is full, it attempts to write an error to errCh; if errCh is full, the error
// passes silently.
func (c *Conn) SetSubStateSubscriber(updateCh chan<- *SubStateUpdate, errCh chan<- error) { … }

func (c *Conn) sendSubStateUpdate(unitPath dbus.ObjectPath) { … }

func (c *Conn) shouldIgnore(path dbus.ObjectPath) bool { … }

func (c *Conn) updateIgnore(path dbus.ObjectPath, info map[string]interface{ … }

// without this, ignore would grow unboundedly over time
func (c *Conn) cleanIgnore() { … }

type PropertiesUpdate …

// SetPropertiesSubscriber writes to updateCh when any unit's properties
// change. Every property change reported by systemd will be sent; that is, no
// transitions will be "missed" (as they might be with SetSubStateSubscriber).
// However, state changes will only be written to the channel with non-blocking
// writes.  If updateCh is full, it attempts to write an error to errCh; if
// errCh is full, the error passes silently.
func (c *Conn) SetPropertiesSubscriber(updateCh chan<- *PropertiesUpdate, errCh chan<- error) { … }

// we don't need to worry about shouldIgnore() here because
// sendPropertiesUpdate doesn't call GetProperties()
func (c *Conn) sendPropertiesUpdate(unitPath dbus.ObjectPath, changedProps map[string]dbus.Variant) { … }