Documentation
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Overview ¶
Package watch contains a generic watchable interface, and a fake for testing code that uses the watch interface.
Index ¶
- type Broadcaster
- type Decoder
- type Event
- type EventType
- type FakeWatcher
- func (f *FakeWatcher) Action(action EventType, obj runtime.Object)
- func (f *FakeWatcher) Add(obj runtime.Object)
- func (f *FakeWatcher) Delete(lastValue runtime.Object)
- func (f *FakeWatcher) Error(errValue runtime.Object)
- func (f *FakeWatcher) Modify(obj runtime.Object)
- func (f *FakeWatcher) ResultChan() <-chan Event
- func (f *FakeWatcher) Stop()
- type FilterFunc
- type FullChannelBehavior
- type Interface
- type StreamWatcher
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Broadcaster ¶ added in v0.7.0
type Broadcaster struct {
// contains filtered or unexported fields
}
Broadcaster distributes event notifications among any number of watchers. Every event is delivered to every watcher.
func NewBroadcaster ¶ added in v0.7.0
func NewBroadcaster(queueLength int, fullChannelBehavior FullChannelBehavior) *Broadcaster
NewBroadcaster creates a new Broadcaster. queueLength is the maximum number of events to queue per watcher. It is guaranteed that events will be distibuted in the order in which they ocur, but the order in which a single event is distributed among all of the watchers is unspecified.
func (*Broadcaster) Action ¶ added in v0.7.0
func (m *Broadcaster) Action(action EventType, obj runtime.Object)
Action distributes the given event among all watchers.
func (*Broadcaster) Shutdown ¶ added in v0.7.0
func (m *Broadcaster) Shutdown()
Shutdown disconnects all watchers (but any queued events will still be distributed). You must not call Action after calling Shutdown.
func (*Broadcaster) Watch ¶ added in v0.7.0
func (m *Broadcaster) Watch() Interface
Watch adds a new watcher to the list and returns an Interface for it. Note: new watchers will only receive new events. They won't get an entire history of previous events.
type Decoder ¶
type Decoder interface { // Decode should return the type of event, the decoded object, or an error. // An error will cause StreamWatcher to call Close(). Decode should block until // it has data or an error occurs. Decode() (action EventType, object runtime.Object, err error) // Close should close the underlying io.Reader, signalling to the source of // the stream that it is no longer being watched. Close() must cause any // outstanding call to Decode() to return with an error of some sort. Close() }
Decoder allows StreamWatcher to watch any stream for which a Decoder can be written.
type Event ¶
type Event struct { Type EventType // Object is: // * If Type is Added or Modified: the new state of the object. // * If Type is Deleted: the state of the object immediately before deletion. // * If Type is Error: *api.Status is recommended; other types may make sense // depending on context. Object runtime.Object }
Event represents a single event to a watched resource.
type FakeWatcher ¶
FakeWatcher lets you test anything that consumes a watch.Interface; threadsafe.
func NewFake ¶
func NewFake() *FakeWatcher
func (*FakeWatcher) Action ¶
func (f *FakeWatcher) Action(action EventType, obj runtime.Object)
Action sends an event of the requested type, for table-based testing.
func (*FakeWatcher) Delete ¶
func (f *FakeWatcher) Delete(lastValue runtime.Object)
Delete sends a delete event.
func (*FakeWatcher) Error ¶
func (f *FakeWatcher) Error(errValue runtime.Object)
Error sends an Error event.
func (*FakeWatcher) Modify ¶
func (f *FakeWatcher) Modify(obj runtime.Object)
Modify sends a modify event.
func (*FakeWatcher) ResultChan ¶
func (f *FakeWatcher) ResultChan() <-chan Event
type FilterFunc ¶
FilterFunc should take an event, possibly modify it in some way, and return the modified event. If the event should be ignored, then return keep=false.
type FullChannelBehavior ¶ added in v0.9.0
type FullChannelBehavior int
FullChannelBehavior controls how the Broadcaster reacts if a watcher's watch channel is full.
const ( WaitIfChannelFull FullChannelBehavior = iota DropIfChannelFull )
type Interface ¶
type Interface interface { // Stops watching. Will close the channel returned by ResultChan(). Releases // any resources used by the watch. Stop() // Returns a chan which will receive all the events. If an error occurs // or Stop() is called, this channel will be closed, in which case the // watch should be completely cleaned up. ResultChan() <-chan Event }
Interface can be implemented by anything that knows how to watch and report changes.
func Filter ¶
func Filter(w Interface, f FilterFunc) Interface
Filter passes all events through f before allowing them to pass on. Putting a filter on a watch, as an unavoidable side-effect due to the way go channels work, effectively causes the watch's event channel to have its queue length increased by one.
WARNING: filter has a fatal flaw, in that it can't properly update the Type field (Add/Modified/Deleted) to reflect items beginning to pass the filter when they previously didn't.
func NewEmptyWatch ¶ added in v0.8.2
func NewEmptyWatch() Interface
NewEmptyWatch returns a watch interface that returns no results and is closed. May be used in certain error conditions where no information is available but an error is not warranted.
type StreamWatcher ¶
StreamWatcher turns any stream for which you can write a Decoder interface into a watch.Interface.
func NewStreamWatcher ¶
func NewStreamWatcher(d Decoder) *StreamWatcher
NewStreamWatcher creates a StreamWatcher from the given decoder.
func (*StreamWatcher) ResultChan ¶
func (sw *StreamWatcher) ResultChan() <-chan Event
ResultChan implements Interface.