// moveTagsTo() gets the tags for all of the src's subiterators and the
// src itself, and moves them to dst.
func moveTagsTo(dst graph.Iterator, src *And) {
	tags := src.getSubTags()
	for _, tag := range dst.Tagger().Tags() {
		if _, ok := tags[tag]; ok {
			delete(tags, tag)
		}
	}
	dt := dst.Tagger()
	for k := range tags {
		dt.Add(k)
	}
}
Exemple #2
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func buildInOutIterator(obj *otto.Object, qs graph.QuadStore, base graph.Iterator, isReverse bool) graph.Iterator {
	argList, _ := obj.Get("_gremlin_values")
	if argList.Class() != "GoArray" {
		glog.Errorln("How is arglist not an array? Return nothing.", argList.Class())
		return iterator.NewNull()
	}
	argArray := argList.Object()
	lengthVal, _ := argArray.Get("length")
	length, _ := lengthVal.ToInteger()
	var predicateNodeIterator graph.Iterator
	if length == 0 {
		predicateNodeIterator = qs.NodesAllIterator()
	} else {
		zero, _ := argArray.Get("0")
		predicateNodeIterator = buildIteratorFromValue(zero, qs)
	}
	if length >= 2 {
		var tags []string
		one, _ := argArray.Get("1")
		if one.IsString() {
			tags = append(tags, one.String())
		} else if one.Class() == "Array" {
			tags = stringsFrom(one.Object())
		}
		for _, tag := range tags {
			predicateNodeIterator.Tagger().Add(tag)
		}
	}

	in, out := quad.Subject, quad.Object
	if isReverse {
		in, out = out, in
	}
	lto := iterator.NewLinksTo(qs, base, in)
	and := iterator.NewAnd(qs)
	and.AddSubIterator(iterator.NewLinksTo(qs, predicateNodeIterator, quad.Predicate))
	and.AddSubIterator(lto)
	return iterator.NewHasA(qs, and, out)
}
Exemple #3
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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 graph.Next(it) {
			n.Values = append(n.Values, s.qs.NameOf(it.Result()))
		}
	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
}
Exemple #4
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func buildIteratorTreeHelper(obj *otto.Object, qs graph.QuadStore, base graph.Iterator) graph.Iterator {
	// TODO: Better error handling
	var (
		it    graph.Iterator
		subIt graph.Iterator
	)

	if prev, _ := obj.Get("_gremlin_prev"); !prev.IsObject() {
		subIt = base
	} else {
		subIt = buildIteratorTreeHelper(prev.Object(), qs, base)
	}

	stringArgs := propertiesOf(obj, "string_args")
	val, _ := obj.Get("_gremlin_type")
	switch val.String() {
	case "vertex":
		if len(stringArgs) == 0 {
			it = qs.NodesAllIterator()
		} else {
			fixed := qs.FixedIterator()
			for _, name := range stringArgs {
				fixed.Add(qs.ValueOf(name))
			}
			it = fixed
		}
	case "tag":
		it = subIt
		for _, tag := range stringArgs {
			it.Tagger().Add(tag)
		}
	case "save":
		all := qs.NodesAllIterator()
		if len(stringArgs) > 2 || len(stringArgs) == 0 {
			return iterator.NewNull()
		}
		if len(stringArgs) == 2 {
			all.Tagger().Add(stringArgs[1])
		} else {
			all.Tagger().Add(stringArgs[0])
		}
		predFixed := qs.FixedIterator()
		predFixed.Add(qs.ValueOf(stringArgs[0]))
		subAnd := iterator.NewAnd(qs)
		subAnd.AddSubIterator(iterator.NewLinksTo(qs, predFixed, quad.Predicate))
		subAnd.AddSubIterator(iterator.NewLinksTo(qs, all, quad.Object))
		hasa := iterator.NewHasA(qs, subAnd, quad.Subject)
		and := iterator.NewAnd(qs)
		and.AddSubIterator(hasa)
		and.AddSubIterator(subIt)
		it = and
	case "saver":
		all := qs.NodesAllIterator()
		if len(stringArgs) > 2 || len(stringArgs) == 0 {
			return iterator.NewNull()
		}
		if len(stringArgs) == 2 {
			all.Tagger().Add(stringArgs[1])
		} else {
			all.Tagger().Add(stringArgs[0])
		}
		predFixed := qs.FixedIterator()
		predFixed.Add(qs.ValueOf(stringArgs[0]))
		subAnd := iterator.NewAnd(qs)
		subAnd.AddSubIterator(iterator.NewLinksTo(qs, predFixed, quad.Predicate))
		subAnd.AddSubIterator(iterator.NewLinksTo(qs, all, quad.Subject))
		hasa := iterator.NewHasA(qs, subAnd, quad.Object)
		and := iterator.NewAnd(qs)
		and.AddSubIterator(hasa)
		and.AddSubIterator(subIt)
		it = and
	case "has":
		fixed := qs.FixedIterator()
		if len(stringArgs) < 2 {
			return iterator.NewNull()
		}
		for _, name := range stringArgs[1:] {
			fixed.Add(qs.ValueOf(name))
		}
		predFixed := qs.FixedIterator()
		predFixed.Add(qs.ValueOf(stringArgs[0]))
		subAnd := iterator.NewAnd(qs)
		subAnd.AddSubIterator(iterator.NewLinksTo(qs, predFixed, quad.Predicate))
		subAnd.AddSubIterator(iterator.NewLinksTo(qs, fixed, quad.Object))
		hasa := iterator.NewHasA(qs, subAnd, quad.Subject)
		and := iterator.NewAnd(qs)
		and.AddSubIterator(hasa)
		and.AddSubIterator(subIt)
		it = and
	case "morphism":
		it = base
	case "and":
		arg, _ := obj.Get("_gremlin_values")
		firstArg, _ := arg.Object().Get("0")
		if !isVertexChain(firstArg.Object()) {
			return iterator.NewNull()
		}
		argIt := buildIteratorTree(firstArg.Object(), qs)

		and := iterator.NewAnd(qs)
		and.AddSubIterator(subIt)
		and.AddSubIterator(argIt)
		it = and
	case "back":
		arg, _ := obj.Get("_gremlin_back_chain")
		argIt := buildIteratorTree(arg.Object(), qs)
		and := iterator.NewAnd(qs)
		and.AddSubIterator(subIt)
		and.AddSubIterator(argIt)
		it = and
	case "is":
		fixed := qs.FixedIterator()
		for _, name := range stringArgs {
			fixed.Add(qs.ValueOf(name))
		}
		and := iterator.NewAnd(qs)
		and.AddSubIterator(fixed)
		and.AddSubIterator(subIt)
		it = and
	case "or":
		arg, _ := obj.Get("_gremlin_values")
		firstArg, _ := arg.Object().Get("0")
		if !isVertexChain(firstArg.Object()) {
			return iterator.NewNull()
		}
		argIt := buildIteratorTree(firstArg.Object(), qs)

		or := iterator.NewOr()
		or.AddSubIterator(subIt)
		or.AddSubIterator(argIt)
		it = or
	case "both":
		// Hardly the most efficient pattern, but the most general.
		// Worth looking into an Optimize() optimization here.
		clone := subIt.Clone()
		it1 := buildInOutIterator(obj, qs, subIt, false)
		it2 := buildInOutIterator(obj, qs, clone, true)

		or := iterator.NewOr()
		or.AddSubIterator(it1)
		or.AddSubIterator(it2)
		it = or
	case "out":
		it = buildInOutIterator(obj, qs, subIt, false)
	case "follow":
		// Follow a morphism
		arg, _ := obj.Get("_gremlin_values")
		firstArg, _ := arg.Object().Get("0")
		if isVertexChain(firstArg.Object()) {
			return iterator.NewNull()
		}
		it = buildIteratorTreeHelper(firstArg.Object(), qs, subIt)
	case "followr":
		// Follow a morphism
		arg, _ := obj.Get("_gremlin_followr")
		if isVertexChain(arg.Object()) {
			return iterator.NewNull()
		}
		it = buildIteratorTreeHelper(arg.Object(), qs, subIt)
	case "in":
		it = buildInOutIterator(obj, qs, subIt, true)
	case "except":
		arg, _ := obj.Get("_gremlin_values")
		firstArg, _ := arg.Object().Get("0")
		if !isVertexChain(firstArg.Object()) {
			return iterator.NewNull()
		}

		allIt := qs.NodesAllIterator()
		toComplementIt := buildIteratorTree(firstArg.Object(), qs)
		notIt := iterator.NewNot(toComplementIt, allIt)

		and := iterator.NewAnd(qs)
		and.AddSubIterator(subIt)
		and.AddSubIterator(notIt)
		it = and
	case "in_predicates":
		it = buildInOutPredicateIterator(obj, qs, subIt, true)
	case "out_predicates":
		it = buildInOutPredicateIterator(obj, qs, subIt, false)
	}
	if it == nil {
		panic("Iterator building does not catch the output iterator in some case.")
	}
	return it
}