Exemple #1
0
func (m *MqlQuery) buildIteratorTreeInternal(query interface{}, path MqlPath) (graph.Iterator, error) {
	var it graph.Iterator
	var err error
	err = nil
	switch t := query.(type) {
	case bool:
		// for JSON booleans
		// Treat the bool as a string and call it a day.
		// Things which are really bool-like are special cases and will be dealt with separately.
		if t {
			it = m.buildFixed("true")
		}
		it = m.buildFixed("false")
	case float64:
		// for JSON numbers
		// Damn you, Javascript, and your lack of integer values.
		if math.Floor(t) == t {
			// Treat it like an integer.
			it = m.buildFixed(fmt.Sprintf("%d", t))
		} else {
			it = m.buildFixed(fmt.Sprintf("%f", t))
		}
	case string:
		// for JSON strings
		it = m.buildFixed(t)
	case []interface{}:
		// for JSON arrays
		m.isRepeated[path] = true
		if len(t) == 0 {
			it = m.buildResultIterator(path)
		} else if len(t) == 1 {
			it, err = m.buildIteratorTreeInternal(t[0], path)
		} else {
			err = errors.New(fmt.Sprintf("Multiple fields at location root%s", path.DisplayString()))
		}
	case map[string]interface{}:
		// for JSON objects
		it, err = m.buildIteratorTreeMapInternal(t, path)
	case nil:
		it = m.buildResultIterator(path)
	default:
		log.Fatal("Unknown JSON type?", query)
	}
	if err != nil {
		return nil, err
	}
	it.AddTag(string(path))
	return it, nil
}
func buildInOutIterator(obj *otto.Object, ts graph.TripleStore, 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 graph.NewNullIterator()
	}
	argArray := argList.Object()
	lengthVal, _ := argArray.Get("length")
	length, _ := lengthVal.ToInteger()
	var predicateNodeIterator graph.Iterator
	if length == 0 {
		predicateNodeIterator = ts.GetNodesAllIterator()
	} else {
		zero, _ := argArray.Get("0")
		predicateNodeIterator = buildIteratorFromValue(zero, ts)
	}
	if length >= 2 {
		var tags []string
		one, _ := argArray.Get("1")
		if one.IsString() {
			s, _ := one.ToString()
			tags = append(tags, s)
		} else if one.Class() == "Array" {
			tags = makeListOfStringsFromArrayValue(one.Object())
		}
		for _, tag := range tags {
			predicateNodeIterator.AddTag(tag)
		}
	}

	in, out := "s", "o"
	if isReverse {
		in, out = out, in
	}
	lto := graph.NewLinksToIterator(ts, base, in)
	and := graph.NewAndIterator()
	and.AddSubIterator(graph.NewLinksToIterator(ts, predicateNodeIterator, "p"))
	and.AddSubIterator(lto)
	return graph.NewHasaIterator(ts, and, out)
}
func buildIteratorTreeHelper(obj *otto.Object, ts graph.TripleStore, base graph.Iterator) graph.Iterator {
	var it graph.Iterator
	it = base
	// TODO: Better error handling
	kindVal, _ := obj.Get("_gremlin_type")
	stringArgs := getStringArgs(obj)
	var subIt graph.Iterator
	prevVal, _ := obj.Get("_gremlin_prev")
	if !prevVal.IsObject() {
		subIt = base
	} else {
		subIt = buildIteratorTreeHelper(prevVal.Object(), ts, base)
	}

	kind, _ := kindVal.ToString()
	switch kind {
	case "vertex":
		if len(stringArgs) == 0 {
			it = ts.GetNodesAllIterator()
		} else {
			fixed := ts.MakeFixed()
			for _, name := range stringArgs {
				fixed.AddValue(ts.GetIdFor(name))
			}
			it = fixed
		}
	case "tag":
		it = subIt
		for _, tag := range stringArgs {
			it.AddTag(tag)
		}
	case "save":
		all := ts.GetNodesAllIterator()
		if len(stringArgs) > 2 || len(stringArgs) == 0 {
			return graph.NewNullIterator()
		}
		if len(stringArgs) == 2 {
			all.AddTag(stringArgs[1])
		} else {
			all.AddTag(stringArgs[0])
		}
		predFixed := ts.MakeFixed()
		predFixed.AddValue(ts.GetIdFor(stringArgs[0]))
		subAnd := graph.NewAndIterator()
		subAnd.AddSubIterator(graph.NewLinksToIterator(ts, predFixed, "p"))
		subAnd.AddSubIterator(graph.NewLinksToIterator(ts, all, "o"))
		hasa := graph.NewHasaIterator(ts, subAnd, "s")
		and := graph.NewAndIterator()
		and.AddSubIterator(hasa)
		and.AddSubIterator(subIt)
		it = and
	case "saver":
		all := ts.GetNodesAllIterator()
		if len(stringArgs) > 2 || len(stringArgs) == 0 {
			return graph.NewNullIterator()
		}
		if len(stringArgs) == 2 {
			all.AddTag(stringArgs[1])
		} else {
			all.AddTag(stringArgs[0])
		}
		predFixed := ts.MakeFixed()
		predFixed.AddValue(ts.GetIdFor(stringArgs[0]))
		subAnd := graph.NewAndIterator()
		subAnd.AddSubIterator(graph.NewLinksToIterator(ts, predFixed, "p"))
		subAnd.AddSubIterator(graph.NewLinksToIterator(ts, all, "s"))
		hasa := graph.NewHasaIterator(ts, subAnd, "o")
		and := graph.NewAndIterator()
		and.AddSubIterator(hasa)
		and.AddSubIterator(subIt)
		it = and
	case "has":
		fixed := ts.MakeFixed()
		if len(stringArgs) < 2 {
			return graph.NewNullIterator()
		}
		for _, name := range stringArgs[1:] {
			fixed.AddValue(ts.GetIdFor(name))
		}
		predFixed := ts.MakeFixed()
		predFixed.AddValue(ts.GetIdFor(stringArgs[0]))
		subAnd := graph.NewAndIterator()
		subAnd.AddSubIterator(graph.NewLinksToIterator(ts, predFixed, "p"))
		subAnd.AddSubIterator(graph.NewLinksToIterator(ts, fixed, "o"))
		hasa := graph.NewHasaIterator(ts, subAnd, "s")
		and := graph.NewAndIterator()
		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 graph.NewNullIterator()
		}
		argIt := buildIteratorTree(firstArg.Object(), ts)

		and := graph.NewAndIterator()
		and.AddSubIterator(subIt)
		and.AddSubIterator(argIt)
		it = and
	case "back":
		arg, _ := obj.Get("_gremlin_back_chain")
		argIt := buildIteratorTree(arg.Object(), ts)
		and := graph.NewAndIterator()
		and.AddSubIterator(subIt)
		and.AddSubIterator(argIt)
		it = and
	case "is":
		fixed := ts.MakeFixed()
		for _, name := range stringArgs {
			fixed.AddValue(ts.GetIdFor(name))
		}
		and := graph.NewAndIterator()
		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 graph.NewNullIterator()
		}
		argIt := buildIteratorTree(firstArg.Object(), ts)

		or := graph.NewOrIterator()
		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, ts, subIt, false)
		it2 := buildInOutIterator(obj, ts, clone, true)

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