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 *minUnitsWatcher) merge(serviceNames *set.Strings, change watcher.Change) error {
serviceName := change.Id.(string)
if change.Revno == -1 {
delete(w.known, serviceName)
serviceNames.Remove(serviceName)
return nil
}
doc := minUnitsDoc{}
if err := w.st.minUnits.FindId(serviceName).One(&doc); err != nil {
return err
}
revno, known := w.known[serviceName]
w.known[serviceName] = doc.Revno
if !known || doc.Revno > revno {
serviceNames.Add(serviceName)
}
return nil
}