func (stringSetSuite) TestUninitialized(c *gc.C) {
var uninitialized set.Strings
c.Assert(uninitialized.Size(), gc.Equals, 0)
c.Assert(uninitialized.IsEmpty(), gc.Equals, true)
// You can get values and sorted values from an unitialized set.
AssertValues(c, uninitialized)
// All contains checks are false
c.Assert(uninitialized.Contains("foo"), gc.Equals, false)
// Remove works on an uninitialized Strings
uninitialized.Remove("foo")
var other set.Strings
// Union returns a new set that is empty but initialized.
c.Assert(uninitialized.Union(other), gc.DeepEquals, set.NewStrings())
c.Assert(uninitialized.Intersection(other), gc.DeepEquals, set.NewStrings())
c.Assert(uninitialized.Difference(other), gc.DeepEquals, set.NewStrings())
other = set.NewStrings("foo", "bar")
c.Assert(uninitialized.Union(other), gc.DeepEquals, other)
c.Assert(uninitialized.Intersection(other), gc.DeepEquals, set.NewStrings())
c.Assert(uninitialized.Difference(other), gc.DeepEquals, set.NewStrings())
c.Assert(other.Union(uninitialized), gc.DeepEquals, other)
c.Assert(other.Intersection(uninitialized), gc.DeepEquals, set.NewStrings())
c.Assert(other.Difference(uninitialized), gc.DeepEquals, other)
// Once something is added, the set becomes initialized.
uninitialized.Add("foo")
AssertValues(c, uninitialized, "foo")
}
func (w *actionWatcher) loop() error {
var (
changes set.Strings
in <-chan watcher.Change = w.source
out chan<- []string = w.sink
)
w.st.watcher.WatchCollectionWithFilter(w.st.actions.Name, w.source, w.filterFn)
defer w.st.watcher.UnwatchCollection(w.st.actions.Name, w.source)
initial, err := w.initial()
if err != nil {
return err
}
changes = initial
for {
select {
case <-w.tomb.Dying():
return tomb.ErrDying
case <-w.st.watcher.Dead():
return stateWatcherDeadError(w.st.watcher.Err())
case ch := <-in:
updates, ok := collect(ch, in, w.tomb.Dying())
if !ok {
return tomb.ErrDying
}
if err := w.merge(changes, initial, updates); err != nil {
return err
}
if !changes.IsEmpty() {
out = w.sink
} else {
out = nil
}
case out <- changes.Values():
changes = set.NewStrings()
out = nil
}
}
}