Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func RunComponent ¶
func RunComponent(ctx context.Context, componentFactory ComponentFactory, handler OnError) error
RunComponent repeatedly starts components returned from the given ComponentFactory, shutting them down when they encounter irrecoverable errors and passing those errors to the given error handler. If the given context is cancelled, it will wait for the current component instance to shutdown before returning. The returned error is either: - The context error if the context was canceled - The last error handled if the error handler returns ErrorHandlingStop - An error returned from componentFactory while generating an instance of component
Types ¶
type Component ¶
type Component interface {
module.Startable
module.ReadyDoneAware
}
Component represents a component which can be started and stopped, and exposes channels that close when startup and shutdown have completed. Once Start has been called, the channel returned by Done must close eventually, whether that be because of a graceful shutdown or an irrecoverable error.
type ComponentFactory ¶
type ComponentManager ¶
type ComponentManager struct {
// contains filtered or unexported fields
}
ComponentManager is used to manage the worker routines of a Component
func (*ComponentManager) Done ¶
func (c *ComponentManager) Done() <-chan struct{}
Done returns a channel which is closed once the ComponentManager has shut down. This happens when all worker routines have shut down (either gracefully or by throwing an error).
func (*ComponentManager) Ready ¶
func (c *ComponentManager) Ready() <-chan struct{}
Ready returns a channel which is closed once all the worker routines have been launched and are ready. If any worker routines exit before they indicate that they are ready, the channel returned from Ready will never close.
func (*ComponentManager) ShutdownSignal ¶
func (c *ComponentManager) ShutdownSignal() <-chan struct{}
ShutdownSignal returns a channel that is closed when shutdown has commenced. This can happen either if the ComponentManager's context is canceled, or a worker routine encounters an irrecoverable error. If this is called before Start, a nil channel will be returned.
func (*ComponentManager) Start ¶
func (c *ComponentManager) Start(parent irrecoverable.SignalerContext)
Start initiates the ComponentManager by launching all worker routines.
type ComponentManagerBuilder ¶
type ComponentManagerBuilder interface {
// AddWorker adds a worker routine for the ComponentManager
AddWorker(ComponentWorker) ComponentManagerBuilder
// Build builds and returns a new ComponentManager instance
Build() *ComponentManager
}
ComponentManagerBuilder provides a mechanism for building a ComponentManager
func NewComponentManagerBuilder ¶
func NewComponentManagerBuilder() ComponentManagerBuilder
NewComponentManagerBuilder returns a new ComponentManagerBuilder
type ComponentWorker ¶
type ComponentWorker func(ctx irrecoverable.SignalerContext, ready ReadyFunc)
ComponentWorker represents a worker routine of a component. It takes a SignalerContext which can be used to throw any irrecoverable errors it encouters, as well as a ReadyFunc which must be called to signal that it is ready. The ComponentManager waits until all workers have signaled that they are ready before closing its own Ready channel.
type ErrorHandlingResult ¶
type ErrorHandlingResult int
const ( ErrorHandlingRestart ErrorHandlingResult = iota ErrorHandlingStop )
type NoopComponent ¶
type NoopComponent struct{}
func (*NoopComponent) Done ¶
func (c *NoopComponent) Done() <-chan struct{}
func (*NoopComponent) Ready ¶
func (c *NoopComponent) Ready() <-chan struct{}
func (*NoopComponent) Start ¶
func (c *NoopComponent) Start(irrecoverable.SignalerContext)
type OnError ¶
type OnError = func(err error) ErrorHandlingResult
OnError reacts to an irrecoverable error It is meant to inspect the error, determining its type and seeing if e.g. a restart or some other measure is suitable, and then return an ErrorHandlingResult indicating how RunComponent should proceed. Before returning, it could also: - panic (in canary / benchmark) - log in various Error channels and / or send telemetry ...
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