Exemple #1
0
// BuildNodeIterator returns an iterator for retrieving the results of the query, with
// each result being a struct representing the node and the values found outgoing at the
// given predicates.
func (gq GraphQuery) BuildNodeIterator(predicates ...Predicate) NodeIterator {
	if (gq.singleDirection == 1 || gq.singleDirection == -1) && gq.singleStartingValue != nil &&
		gq.singlePredicate != nil && len(predicates) == 0 {

		// Special case: An iterator from a single starting node in a single direction over
		// a single predicate with no custom values.
		return newSimpleDirectionalIterator(gq.layer, gq.singleStartingValue, gq.singlePredicate, gq.singleDirection)
	}

	var updatedPath *path.Path = gq.path

	// Save the predicates the user requested.
	for _, predicate := range predicates {
		fullPredicate := gq.layer.getPrefixedPredicate(predicate)
		updatedPath = updatedPath.Save(fullPredicate, valueToPredicateString(fullPredicate))
	}

	// Save the predicate for the kind of the node as well.
	fullKindPredicate := gq.layer.getPrefixedPredicate(gq.layer.nodeKindPredicate)
	updatedPath = updatedPath.Save(fullKindPredicate, valueToPredicateString(fullKindPredicate))

	it := updatedPath.BuildIterator()
	oit, _ := it.Optimize()

	return &graphNodeIterator{
		layer:    gq.layer,
		iterator: oit,
		tagCount: gq.tagCount + 1 + len(predicates), // +1 for kind.
	}
}
Exemple #2
0
func buildPathFromObject(obj *otto.Object) *path.Path {
	var p *path.Path
	val, _ := obj.Get("_gremlin_type")
	stringArgs := propertiesOf(obj, "string_args")
	gremlinType := val.String()
	if prev, _ := obj.Get("_gremlin_prev"); !prev.IsObject() {
		switch gremlinType {
		case "vertex":
			return path.StartMorphism(stringArgs...)
		case "morphism":
			return path.StartMorphism()
		default:
			panic("No base gremlin path other than 'vertex' or 'morphism'")
		}
	} else {
		p = buildPathFromObject(prev.Object())
	}
	if p == nil {
		return nil
	}
	switch gremlinType {
	case "Is":
		return p.Is(stringArgs...)
	case "In":
		preds, tags, ok := getViaData(obj)
		if !ok {
			return nil
		}
		return p.InWithTags(tags, preds...)
	case "Out":
		preds, tags, ok := getViaData(obj)
		if !ok {
			return nil
		}
		return p.OutWithTags(tags, preds...)
	case "Both":
		preds, _, ok := getViaData(obj)
		if !ok {
			return nil
		}
		return p.Both(preds...)
	case "Follow":
		subobj := getFirstArgAsMorphismChain(obj)
		if subobj == nil {
			return nil
		}
		return p.Follow(buildPathFromObject(subobj))
	case "FollowR":
		subobj := getFirstArgAsMorphismChain(obj)
		if subobj == nil {
			return nil
		}
		return p.FollowReverse(buildPathFromObject(subobj))
	case "And", "Intersect":
		subobj := getFirstArgAsVertexChain(obj)
		if subobj == nil {
			return nil
		}
		return p.And(buildPathFromObject(subobj))
	case "Union", "Or":
		subobj := getFirstArgAsVertexChain(obj)
		if subobj == nil {
			return nil
		}
		return p.Or(buildPathFromObject(subobj))
	case "Back":
		if len(stringArgs) != 1 {
			return nil
		}
		return p.Back(stringArgs[0])
	case "Tag", "As":
		return p.Tag(stringArgs...)
	case "Has":
		if len(stringArgs) < 2 {
			return nil
		}
		return p.Has(stringArgs[0], stringArgs[1:]...)
	case "Save", "SaveR":
		if len(stringArgs) > 2 || len(stringArgs) == 0 {
			return nil
		}
		tag := stringArgs[0]
		if len(stringArgs) == 2 {
			tag = stringArgs[1]
		}
		if gremlinType == "SaveR" {
			return p.SaveReverse(stringArgs[0], tag)
		}
		return p.Save(stringArgs[0], tag)
	case "Except", "Difference":
		subobj := getFirstArgAsVertexChain(obj)
		if subobj == nil {
			return nil
		}
		return p.Except(buildPathFromObject(subobj))
	case "InPredicates":
		return p.InPredicates()
	case "OutPredicates":
		return p.OutPredicates()
	case "LabelContext":
		labels, tags, ok := getViaData(obj)
		if !ok {
			return nil
		}
		return p.LabelContextWithTags(tags, labels...)
	default:
		panic(fmt.Sprint("Unimplemented Gremlin function", gremlinType))
	}
}