Golang Iterator.Next方法代码示例

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 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 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 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()
			})
		})
	})

}