Golang Iterator.Next方法代码示例

func iterated(it graph.Iterator) []int {
	var res []int
	for it.Next() {
		res = append(res, int(it.Result().(Int64Node)))
	}
	return res
}

func IteratedQuads(t testing.TB, qs graph.QuadStore, it graph.Iterator) []quad.Quad {
	var res quad.ByQuadString
	for it.Next() {
		res = append(res, qs.Quad(it.Result()))
	}
	require.Nil(t, it.Err())
	sort.Sort(res)
	return res
}

func IteratedValues(t testing.TB, qs graph.QuadStore, it graph.Iterator) []quad.Value {
	var res []quad.Value
	for it.Next() {
		res = append(res, qs.NameOf(it.Result()))
	}
	require.Nil(t, it.Err())
	sort.Sort(quad.ByValueString(res))
	return res
}

func IteratedRawStrings(t testing.TB, qs graph.QuadStore, it graph.Iterator) []string {
	var res []string
	for it.Next() {
		res = append(res, qs.NameOf(it.Result()).String())
	}
	require.Nil(t, it.Err())
	sort.Strings(res)
	return res
}

func (s *queryShape) MakeNode(it graph.Iterator) *Node {
	n := Node{ID: s.nodeID}
	for _, tag := range it.Tagger().Tags() {
		n.Tags = append(n.Tags, tag)
	}
	for k := range it.Tagger().Fixed() {
		n.Tags = append(n.Tags, k)
	}

	switch it.Type() {
	case graph.And:
		for _, sub := range it.SubIterators() {
			s.nodeID++
			newNode := s.MakeNode(sub)
			if sub.Type() != graph.Or {
				s.StealNode(&n, newNode)
			} else {
				s.AddNode(newNode)
				s.AddLink(&Link{n.ID, newNode.ID, 0, 0})
			}
		}
	case graph.Fixed:
		n.IsFixed = true
		for it.Next() {
			n.Values = append(n.Values, s.qs.NameOf(it.Result()).String())
		}
	case graph.HasA:
		hasa := it.(*HasA)
		s.PushHasa(n.ID, hasa.dir)
		s.nodeID++
		newNode := s.MakeNode(hasa.primaryIt)
		s.AddNode(newNode)
		s.RemoveHasa()
	case graph.Or:
		for _, sub := range it.SubIterators() {
			s.nodeID++
			newNode := s.MakeNode(sub)
			if sub.Type() == graph.Or {
				s.StealNode(&n, newNode)
			} else {
				s.AddNode(newNode)
				s.AddLink(&Link{n.ID, newNode.ID, 0, 0})
			}
		}
	case graph.LinksTo:
		n.IsLinkNode = true
		lto := it.(*LinksTo)
		s.nodeID++
		newNode := s.MakeNode(lto.primaryIt)
		hasaID, hasaDir := s.LastHasa()
		if (hasaDir == quad.Subject && lto.dir == quad.Object) ||
			(hasaDir == quad.Object && lto.dir == quad.Subject) {
			s.AddNode(newNode)
			if hasaDir == quad.Subject {
				s.AddLink(&Link{hasaID, newNode.ID, 0, n.ID})
			} else {
				s.AddLink(&Link{newNode.ID, hasaID, 0, n.ID})
			}
		} else if lto.primaryIt.Type() == graph.Fixed {
			s.StealNode(&n, newNode)
		} else {
			s.AddNode(newNode)
		}
	case graph.Optional:
		// Unsupported, for the moment
		fallthrough
	case graph.All:
	}
	return &n
}

func TestIterator(t testing.TB, gen DatabaseFunc) {
	qs, opts, closer := gen(t)
	defer closer()

	MakeWriter(t, qs, opts, MakeQuadSet()...)

	var it graph.Iterator

	it = qs.NodesAllIterator()
	require.NotNil(t, it)

	size, _ := it.Size()
	require.True(t, size > 0 && size < 20, "Unexpected size")
	// TODO: leveldb had this test
	//if exact {
	//	t.Errorf("Got unexpected exact result.")
	//}
	require.Equal(t, graph.All, it.Type(), "Unexpected iterator type")

	optIt, changed := it.Optimize()
	require.True(t, !changed && optIt == it, "Optimize unexpectedly changed iterator: %v, %T", changed, optIt)

	expect := []string{
		"A",
		"B",
		"C",
		"D",
		"E",
		"F",
		"G",
		"follows",
		"status",
		"cool",
		"status_graph",
	}
	sort.Strings(expect)
	for i := 0; i < 2; i++ {
		got := IteratedRawStrings(t, qs, it)
		sort.Strings(got)
		require.Equal(t, expect, got, "Unexpected iterated result on repeat %d", i)
		it.Reset()
	}

	for _, pq := range expect {
		require.True(t, it.Contains(qs.ValueOf(quad.Raw(pq))), "Failed to find and check %q correctly", pq)

	}
	// FIXME(kortschak) Why does this fail?
	/*
		for _, pq := range []string{"baller"} {
			if it.Contains(qs.ValueOf(pq)) {
				t.Errorf("Failed to check %q correctly", pq)
			}
		}
	*/
	it.Reset()

	it = qs.QuadsAllIterator()
	optIt, changed = it.Optimize()
	require.True(t, !changed && optIt == it, "Optimize unexpectedly changed iterator: %v, %T", changed, optIt)

	require.True(t, it.Next())

	q := qs.Quad(it.Result())
	require.Nil(t, it.Err())
	require.True(t, q.IsValid(), "Invalid quad returned: %q", q)
	set := MakeQuadSet()
	var ok bool
	for _, e := range set {
		if e.String() == q.String() {
			ok = true
			break
		}
	}
	require.True(t, ok, "Failed to find %q during iteration, got:%q", q, set)
}