Golang Strings.Size方法代碼示例

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")
}

// Helper methods for the tests.
func AssertValues(c *gc.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, gc.DeepEquals, expected)
	c.Assert(s.Size(), gc.Equals, len(expected))
	// Check the sorted values too.
	sorted := s.SortedValues()
	c.Assert(sorted, gc.DeepEquals, expected)
}

// commonServiceInstances returns instances with
// services in common with the specified machine.
func commonServiceInstances(st *state.State, m *state.Machine) ([]instance.Id, error) {
	units, err := m.Units()
	if err != nil {
		return nil, err
	}
	var instanceIdSet set.Strings
	for _, unit := range units {
		if !unit.IsPrincipal() {
			continue
		}
		service, err := unit.Service()
		if err != nil {
			return nil, err
		}
		allUnits, err := service.AllUnits()
		if err != nil {
			return nil, err
		}
		for _, unit := range allUnits {
			machineId, err := unit.AssignedMachineId()
			if state.IsNotAssigned(err) {
				continue
			} else if err != nil {
				return nil, err
			}
			machine, err := st.Machine(machineId)
			if err != nil {
				return nil, err
			}
			instanceId, err := machine.InstanceId()
			if err == nil {
				instanceIdSet.Add(string(instanceId))
			} else if state.IsNotProvisionedError(err) {
				continue
			} else {
				return nil, err
			}
		}
	}
	instanceIds := make([]instance.Id, instanceIdSet.Size())
	// Sort values to simplify testing.
	for i, instanceId := range instanceIdSet.SortedValues() {
		instanceIds[i] = instance.Id(instanceId)
	}
	return instanceIds, nil
}