Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5
Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/vendor/k8s.io/apimachinery/pkg/watch/filter.go b/vendor/k8s.io/apimachinery/pkg/watch/filter.go
new file mode 100644
index 0000000..22c9449
--- /dev/null
+++ b/vendor/k8s.io/apimachinery/pkg/watch/filter.go
@@ -0,0 +1,105 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package watch
+
+import (
+ "sync"
+)
+
+// 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 FilterFunc func(in Event) (out Event, keep bool)
+
+// 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 Filter(w Interface, f FilterFunc) Interface {
+ fw := &filteredWatch{
+ incoming: w,
+ result: make(chan Event),
+ f: f,
+ }
+ go fw.loop()
+ return fw
+}
+
+type filteredWatch struct {
+ incoming Interface
+ result chan Event
+ f FilterFunc
+}
+
+// ResultChan returns a channel which will receive filtered events.
+func (fw *filteredWatch) ResultChan() <-chan Event {
+ return fw.result
+}
+
+// Stop stops the upstream watch, which will eventually stop this watch.
+func (fw *filteredWatch) Stop() {
+ fw.incoming.Stop()
+}
+
+// loop waits for new values, filters them, and resends them.
+func (fw *filteredWatch) loop() {
+ defer close(fw.result)
+ for event := range fw.incoming.ResultChan() {
+ filtered, keep := fw.f(event)
+ if keep {
+ fw.result <- filtered
+ }
+ }
+}
+
+// Recorder records all events that are sent from the watch until it is closed.
+type Recorder struct {
+ Interface
+
+ lock sync.Mutex
+ events []Event
+}
+
+var _ Interface = &Recorder{}
+
+// NewRecorder wraps an Interface and records any changes sent across it.
+func NewRecorder(w Interface) *Recorder {
+ r := &Recorder{}
+ r.Interface = Filter(w, r.record)
+ return r
+}
+
+// record is a FilterFunc and tracks each received event.
+func (r *Recorder) record(in Event) (Event, bool) {
+ r.lock.Lock()
+ defer r.lock.Unlock()
+ r.events = append(r.events, in)
+ return in, true
+}
+
+// Events returns a copy of the events sent across this recorder.
+func (r *Recorder) Events() []Event {
+ r.lock.Lock()
+ defer r.lock.Unlock()
+ copied := make([]Event, len(r.events))
+ copy(copied, r.events)
+ return copied
+}