internal

Documentation

Index

• Constants
• type WatcherState
  • func NewWatcherState(l log.Logger) *WatcherState
  • func (s *WatcherState) IsDraining() bool
  • func (s *WatcherState) IsStopping() bool
  • func (s *WatcherState) Transition(next int)
  • func (s *WatcherState) WaitForStopping() <-chan struct{}

Constants

const (
	// StateRunning is the main functioning state of the watcher. It will keep tailing head segments, consuming closed
	// ones, and checking for new ones.
	StateRunning = iota

	// StateDraining is an intermediary state between running and stopping. The watcher will attempt to consume all the data
	// found in the WAL, omitting errors and assuming all segments found are "closed", that is, no longer being written.
	StateDraining

	// StateStopping means the Watcher is being stopped. It should drop all segment read activity, and exit promptly.
	StateStopping
)

Types

type WatcherState

type WatcherState struct {
	// contains filtered or unexported fields
}

WatcherState is a holder for the state the Watcher is in. It provides handy methods for checking it it's stopping, getting the current state, or blocking until it has stopped.

func NewWatcherState

func NewWatcherState(l log.Logger) *WatcherState

func (*WatcherState) IsDraining

func (s *WatcherState) IsDraining() bool

IsDraining evaluates to true if the current state is StateDraining.

func (*WatcherState) IsStopping

func (s *WatcherState) IsStopping() bool

IsStopping evaluates to true if the current state is StateStopping.

func (*WatcherState) Transition

func (s *WatcherState) Transition(next int)

Transition changes the state of WatcherState to next, reacting accordingly.

func (*WatcherState) WaitForStopping

func (s *WatcherState) WaitForStopping() <-chan struct{}

WaitForStopping returns a channel in which the called can read, effectively waiting until the state changes to stopping.