Golang set.Strings類代碼示例

func (*statusContext) processRelations(service *state.Service) (related map[string][]string, subord []string, err error) {
	// TODO(mue) This way the same relation is read twice (for each service).
	// Maybe add Relations() to state, read them only once and pass them to each
	// call of this function.
	relations, err := service.Relations()
	if err != nil {
		return nil, nil, err
	}
	var subordSet set.Strings
	related = make(map[string][]string)
	for _, relation := range relations {
		ep, err := relation.Endpoint(service.Name())
		if err != nil {
			return nil, nil, err
		}
		relationName := ep.Relation.Name
		eps, err := relation.RelatedEndpoints(service.Name())
		if err != nil {
			return nil, nil, err
		}
		for _, ep := range eps {
			if ep.Scope == charm.ScopeContainer && !service.IsPrincipal() {
				subordSet.Add(ep.ServiceName)
			}
			related[relationName] = append(related[relationName], ep.ServiceName)
		}
	}
	for relationName, serviceNames := range related {
		sn := set.NewStrings(serviceNames...)
		related[relationName] = sn.SortedValues()
	}
	return related, subordSet.SortedValues(), nil
}

// collect calls f on all values in src and returns an alphabetically
// ordered list of the returned results without duplicates.
func (src List) collect(f func(*Tools) string) []string {
	var seen set.Strings
	for _, tools := range src {
		seen.Add(f(tools))
	}
	return seen.SortedValues()
}

// fetchMachines returns a map from top level machine id to machines, where machines[0] is the host
// machine and machines[1..n] are any containers (including nested ones).
//
// If machineIds is non-nil, only machines whose IDs are in the set are returned.
func fetchMachines(st *state.State, machineIds *set.Strings) (map[string][]*state.Machine, error) {
	v := make(map[string][]*state.Machine)
	machines, err := st.AllMachines()
	if err != nil {
		return nil, err
	}
	// AllMachines gives us machines sorted by id.
	for _, m := range machines {
		if machineIds != nil && !machineIds.Contains(m.Id()) {
			continue
		}
		parentId, ok := m.ParentId()
		if !ok {
			// Only top level host machines go directly into the machine map.
			v[m.Id()] = []*state.Machine{m}
		} else {
			topParentId := state.TopParentId(m.Id())
			machines, ok := v[topParentId]
			if !ok {
				panic(fmt.Errorf("unexpected machine id %q", parentId))
			}
			machines = append(machines, m)
			v[topParentId] = machines
		}
	}
	return v, nil
}

func (w *minUnitsWatcher) initial() (*set.Strings, error) {
	serviceNames := new(set.Strings)
	doc := &minUnitsDoc{}
	iter := w.st.minUnits.Find(nil).Iter()
	for iter.Next(doc) {
		w.known[doc.ServiceName] = doc.Revno
		serviceNames.Add(doc.ServiceName)
	}
	return serviceNames, iter.Err()
}

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
}

// fetchUnitMachineIds returns a set of IDs for machines that
// the specified units reside on, and those machines' ancestors.
func fetchUnitMachineIds(units map[string]map[string]*state.Unit) (*set.Strings, error) {
	machineIds := new(set.Strings)
	for _, svcUnitMap := range units {
		for _, unit := range svcUnitMap {
			if !unit.IsPrincipal() {
				continue
			}
			mid, err := unit.AssignedMachineId()
			if err != nil {
				return nil, err
			}
			for mid != "" {
				machineIds.Add(mid)
				mid = state.ParentId(mid)
			}
		}
	}
	return machineIds, nil
}

// Helper methods for the tests.
func AssertValues(c *C, s set.Strings, expected ...string) {
	values := s.Values()
	// Expect an empty slice, not a nil slice for values.
	if expected == nil {
		expected = []string{}
	}
	sort.Strings(expected)
	sort.Strings(values)
	c.Assert(values, DeepEquals, expected)
	c.Assert(s.Size(), Equals, len(expected))
	// Check the sorted values too.
	sorted := s.SortedValues()
	c.Assert(sorted, DeepEquals, expected)
}

func (stringSetSuite) TestUninitialized(c *C) {
	var uninitialized set.Strings
	c.Assert(uninitialized.Size(), Equals, 0)
	c.Assert(uninitialized.IsEmpty(), 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"), 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), DeepEquals, set.NewStrings())
	c.Assert(uninitialized.Intersection(other), DeepEquals, set.NewStrings())
	c.Assert(uninitialized.Difference(other), DeepEquals, set.NewStrings())

	other = set.NewStrings("foo", "bar")
	c.Assert(uninitialized.Union(other), DeepEquals, other)
	c.Assert(uninitialized.Intersection(other), DeepEquals, set.NewStrings())
	c.Assert(uninitialized.Difference(other), DeepEquals, set.NewStrings())
	c.Assert(other.Union(uninitialized), DeepEquals, other)
	c.Assert(other.Intersection(uninitialized), DeepEquals, set.NewStrings())
	c.Assert(other.Difference(uninitialized), DeepEquals, other)

	// Once something is added, the set becomes initialized.
	uninitialized.Add("foo")
	AssertValues(c, uninitialized, "foo")
}