Golang Graph.Iterator类代码示例

func (ts *LevelDBTripleStore) OptimizeIterator(it graph.Iterator) (graph.Iterator, bool) {
	switch it.Type() {
	case "linksto":
		return ts.optimizeLinksTo(it.(*graph.LinksToIterator))

	}
	return it, false
}

func (m *MongoIterator) Clone() graph.Iterator {
	var newM graph.Iterator
	if m.isAll {
		newM = NewMongoAllIterator(m.ts, m.collection)
	} else {
		newM = NewMongoIterator(m.ts, m.collection, m.dir, m.hash)
	}
	newM.CopyTagsFrom(m)
	return newM
}

func extractValuesFromIterator(ts graph.TripleStore, it graph.Iterator) []string {
	var output []string
	for {
		val, ok := it.Next()
		if !ok {
			break
		}
		output = append(output, ts.GetNameFor(val))
	}
	return output
}

func extractTripleFromIterator(ts graph.TripleStore, it graph.Iterator) []string {
	var output []string
	for {
		val, ok := it.Next()
		if !ok {
			break
		}
		output = append(output, ts.GetTriple(val).ToString())
	}
	return output
}

func TestOptimize(t *testing.T) {
	var ts *LevelDBTripleStore
	var lto graph.Iterator
	var tmpDir string

	Convey("Given a prepared database", t, func() {
		tmpDir, _ = ioutil.TempDir(os.TempDir(), "cayley_test")
		t.Log(tmpDir)
		defer os.RemoveAll(tmpDir)
		ok := CreateNewLevelDB(tmpDir)
		So(ok, ShouldBeTrue)
		ts = NewDefaultLevelDBTripleStore(tmpDir, nil)
		ts.AddTripleSet(makeTripleSet())

		Convey("With an linksto-fixed pair", func() {
			fixed := ts.MakeFixed()
			fixed.AddValue(ts.GetIdFor("F"))
			fixed.AddTag("internal")
			lto = graph.NewLinksToIterator(ts, fixed, "o")

			Convey("Creates an appropriate iterator", func() {
				oldIt := lto.Clone()
				newIt, ok := lto.Optimize()
				So(ok, ShouldBeTrue)
				So(newIt.Type(), ShouldEqual, "leveldb")

				Convey("Containing the right things", func() {
					afterOp := extractTripleFromIterator(ts, newIt)
					beforeOp := extractTripleFromIterator(ts, oldIt)
					sort.Strings(afterOp)
					sort.Strings(beforeOp)
					So(afterOp, ShouldResemble, beforeOp)
				})

				Convey("With the correct tags", func() {
					oldIt.Next()
					newIt.Next()
					oldResults := make(map[string]graph.TSVal)
					oldIt.TagResults(&oldResults)
					newResults := make(map[string]graph.TSVal)
					oldIt.TagResults(&newResults)
					So(newResults, ShouldResemble, oldResults)
				})

			})

		})

	})

}

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 runIteratorToArrayNoTags(it graph.Iterator, ses *GremlinSession, limit int) []string {
	output := make([]string, 0)
	count := 0
	it, _ = it.Optimize()
	for {
		if ses.doHalt {
			return nil
		}
		val, ok := it.Next()
		if !ok {
			break
		}
		output = append(output, ses.ts.GetNameFor(val))
		count++
		if limit >= 0 && count >= limit {
			break
		}
	}
	it.Close()
	return output
}

func runIteratorOnSession(it graph.Iterator, ses *GremlinSession) {
	if ses.lookingForQueryShape {
		graph.OutputQueryShapeForIterator(it, ses.ts, &(ses.queryShape))
		return
	}
	it, _ = it.Optimize()
	glog.V(2).Infoln(it.DebugString(0))
	for {
		// TODO(barakmich): Better halting.
		if ses.doHalt {
			return
		}
		_, ok := it.Next()
		if !ok {
			break
		}
		tags := make(map[string]graph.TSVal)
		it.TagResults(&tags)
		cont := ses.SendResult(&GremlinResult{metaresult: false, err: "", val: nil, actualResults: &tags})
		if !cont {
			break
		}
		for it.NextResult() == true {
			if ses.doHalt {
				return
			}
			tags := make(map[string]graph.TSVal)
			it.TagResults(&tags)
			cont := ses.SendResult(&GremlinResult{metaresult: false, err: "", val: nil, actualResults: &tags})
			if !cont {
				break
			}
		}
	}
	it.Close()
}

func runIteratorWithCallback(it graph.Iterator, ses *GremlinSession, callback otto.Value, this otto.FunctionCall, limit int) {
	count := 0
	it, _ = it.Optimize()
	for {
		if ses.doHalt {
			return
		}
		_, ok := it.Next()
		if !ok {
			break
		}
		tags := make(map[string]graph.TSVal)
		it.TagResults(&tags)
		val, _ := this.Otto.ToValue(tagsToValueMap(tags, ses))
		val, _ = callback.Call(this.This, val)
		count++
		if limit >= 0 && count >= limit {
			break
		}
		for it.NextResult() == true {
			if ses.doHalt {
				return
			}
			tags := make(map[string]graph.TSVal)
			it.TagResults(&tags)
			val, _ := this.Otto.ToValue(tagsToValueMap(tags, ses))
			val, _ = callback.Call(this.This, val)
			count++
			if limit >= 0 && count >= limit {
				break
			}
		}
	}
	it.Close()
}

func runIteratorToArray(it graph.Iterator, ses *GremlinSession, limit int) []map[string]string {
	output := make([]map[string]string, 0)
	count := 0
	it, _ = it.Optimize()
	for {
		if ses.doHalt {
			return nil
		}
		_, ok := it.Next()
		if !ok {
			break
		}
		tags := make(map[string]graph.TSVal)
		it.TagResults(&tags)
		output = append(output, tagsToValueMap(tags, ses))
		count++
		if limit >= 0 && count >= limit {
			break
		}
		for it.NextResult() == true {
			if ses.doHalt {
				return nil
			}
			tags := make(map[string]graph.TSVal)
			it.TagResults(&tags)
			output = append(output, tagsToValueMap(tags, ses))
			count++
			if limit >= 0 && count >= limit {
				break
			}
		}
	}
	it.Close()
	return output
}

func TestSetIterator(t *testing.T) {
	var ts *LevelDBTripleStore
	var tmpDir string

	Convey("Given a prepared database", t, func() {
		tmpDir, _ = ioutil.TempDir(os.TempDir(), "cayley_test")
		t.Log(tmpDir)
		defer os.RemoveAll(tmpDir)
		ok := CreateNewLevelDB(tmpDir)
		So(ok, ShouldBeTrue)
		ts = NewDefaultLevelDBTripleStore(tmpDir, nil)
		ts.AddTripleSet(makeTripleSet())
		var it graph.Iterator

		Convey("Can create a subject iterator", func() {
			it = ts.GetTripleIterator("s", ts.GetIdFor("C"))

			Convey("Containing the right things", func() {
				expected := []string{
					graph.MakeTriple("C", "follows", "B", "").ToString(),
					graph.MakeTriple("C", "follows", "D", "").ToString(),
				}
				actual := extractTripleFromIterator(ts, it)
				sort.Strings(actual)
				sort.Strings(expected)
				So(actual, ShouldResemble, expected)
			})

			Convey("And checkable", func() {
				and := graph.NewAndIterator()
				and.AddSubIterator(ts.GetTriplesAllIterator())
				and.AddSubIterator(it)

				expected := []string{
					graph.MakeTriple("C", "follows", "B", "").ToString(),
					graph.MakeTriple("C", "follows", "D", "").ToString(),
				}
				actual := extractTripleFromIterator(ts, and)
				sort.Strings(actual)
				sort.Strings(expected)
				So(actual, ShouldResemble, expected)
			})
			Reset(func() {
				it.Reset()
			})

		})

		Convey("Can create an object iterator", func() {
			it = ts.GetTripleIterator("o", ts.GetIdFor("F"))

			Convey("Containing the right things", func() {
				expected := []string{
					graph.MakeTriple("B", "follows", "F", "").ToString(),
					graph.MakeTriple("E", "follows", "F", "").ToString(),
				}
				actual := extractTripleFromIterator(ts, it)
				sort.Strings(actual)
				sort.Strings(expected)
				So(actual, ShouldResemble, expected)
			})

			Convey("Mutually and-checkable", func() {
				and := graph.NewAndIterator()
				and.AddSubIterator(ts.GetTripleIterator("s", ts.GetIdFor("B")))
				and.AddSubIterator(it)

				expected := []string{
					graph.MakeTriple("B", "follows", "F", "").ToString(),
				}
				actual := extractTripleFromIterator(ts, and)
				sort.Strings(actual)
				sort.Strings(expected)
				So(actual, ShouldResemble, expected)
			})

		})

		Convey("Can create a predicate iterator", func() {
			it = ts.GetTripleIterator("p", ts.GetIdFor("status"))

			Convey("Containing the right things", func() {
				expected := []string{
					graph.MakeTriple("B", "status", "cool", "status_graph").ToString(),
					graph.MakeTriple("D", "status", "cool", "status_graph").ToString(),
					graph.MakeTriple("G", "status", "cool", "status_graph").ToString(),
				}
				actual := extractTripleFromIterator(ts, it)
				sort.Strings(actual)
				sort.Strings(expected)
				So(actual, ShouldResemble, expected)
			})

		})

		Convey("Can create a provenance iterator", func() {
			it = ts.GetTripleIterator("c", ts.GetIdFor("status_graph"))

			Convey("Containing the right things", func() {
				expected := []string{
//.........这里部分代码省略.........

func TestAllIterator(t *testing.T) {
	var ts *LevelDBTripleStore

	Convey("Given a prepared database", t, func() {
		tmpDir, _ := ioutil.TempDir(os.TempDir(), "cayley_test")
		t.Log(tmpDir)
		defer os.RemoveAll(tmpDir)
		ok := CreateNewLevelDB(tmpDir)
		So(ok, ShouldBeTrue)
		ts = NewDefaultLevelDBTripleStore(tmpDir, nil)
		ts.AddTripleSet(makeTripleSet())
		var it graph.Iterator

		Convey("Can create an all iterator for nodes", func() {
			it = ts.GetNodesAllIterator()
			So(it, ShouldNotBeNil)

			Convey("Has basics", func() {
				size, accurate := it.Size()
				So(size, ShouldBeBetween, 0, 20)
				So(accurate, ShouldBeFalse)
				So(it.Type(), ShouldEqual, "all")
				re_it, ok := it.Optimize()
				So(ok, ShouldBeFalse)
				So(re_it, ShouldPointTo, it)
			})

			Convey("Iterates all nodes", func() {
				expected := []string{
					"A",
					"B",
					"C",
					"D",
					"E",
					"F",
					"G",
					"follows",
					"status",
					"cool",
					"status_graph",
				}
				sort.Strings(expected)
				actual := extractValuesFromIterator(ts, it)
				sort.Strings(actual)
				So(actual, ShouldResemble, expected)
				it.Reset()
				actual = extractValuesFromIterator(ts, it)
				sort.Strings(actual)
				So(actual, ShouldResemble, expected)

			})

			Convey("Contains a couple nodes", func() {
				So(it.Check(ts.GetIdFor("A")), ShouldBeTrue)
				So(it.Check(ts.GetIdFor("cool")), ShouldBeTrue)
				//So(it.Check(ts.GetIdFor("baller")), ShouldBeFalse)
			})

			Reset(func() {
				it.Reset()
			})
		})

		Convey("Can create an all iterator for edges", func() {
			it := ts.GetTriplesAllIterator()
			So(it, ShouldNotBeNil)
			Convey("Has basics", func() {
				size, accurate := it.Size()
				So(size, ShouldBeBetween, 0, 20)
				So(accurate, ShouldBeFalse)
				So(it.Type(), ShouldEqual, "all")
				re_it, ok := it.Optimize()
				So(ok, ShouldBeFalse)
				So(re_it, ShouldPointTo, it)
			})

			Convey("Iterates an edge", func() {
				edge_val, _ := it.Next()
				triple := ts.GetTriple(edge_val)
				set := makeTripleSet()
				var string_set []string
				for _, t := range set {
					string_set = append(string_set, t.ToString())
				}
				So(triple.ToString(), ShouldBeIn, string_set)
			})

			Reset(func() {
				ts.Close()
			})
		})
	})

}

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()
//.........这里部分代码省略.........