package collection import ( "fmt" "math/rand" "reflect" "strconv" "testing" "time" "github.com/tidwall/geojson" "github.com/tidwall/geojson/geometry" "github.com/tidwall/gjson" ) func PO(x, y float64) *geojson.Point { return geojson.NewPoint(geometry.Point{X: x, Y: y}) } func init() { seed := time.Now().UnixNano() println(seed) rand.Seed(seed) } func expect(t testing.TB, expect bool) { t.Helper() if !expect { t.Fatal("not what you expected") } } func bounds(c *Collection) geometry.Rect { minX, minY, maxX, maxY := c.Bounds() return geometry.Rect{ Min: geometry.Point{X: minX, Y: minY}, Max: geometry.Point{X: maxX, Y: maxY}, } } func TestCollectionNewCollection(t *testing.T) { const numItems = 10000 objs := make(map[string]geojson.Object) c := New() for i := 0; i < numItems; i++ { id := strconv.FormatInt(int64(i), 10) var obj geojson.Object obj = PO(rand.Float64()*360-180, rand.Float64()*180-90) objs[id] = obj c.Set(id, obj, nil, nil) } count := 0 bbox := geometry.Rect{ Min: geometry.Point{X: -180, Y: -90}, Max: geometry.Point{X: 180, Y: 90}, } c.geoSearch(bbox, func(id string, obj geojson.Object, field []float64) bool { count++ return true }) if count != len(objs) { t.Fatalf("count = %d, expect %d", count, len(objs)) } count = c.Count() if count != len(objs) { t.Fatalf("c.Count() = %d, expect %d", count, len(objs)) } testCollectionVerifyContents(t, c, objs) } func TestCollectionSet(t *testing.T) { t.Run("AddString", func(t *testing.T) { c := New() str1 := String("hello") oldObject, oldFields, newFields := c.Set("str", str1, nil, nil) expect(t, oldObject == nil) expect(t, len(oldFields) == 0) expect(t, len(newFields) == 0) }) t.Run("UpdateString", func(t *testing.T) { c := New() str1 := String("hello") str2 := String("world") oldObject, oldFields, newFields := c.Set("str", str1, nil, nil) expect(t, oldObject == nil) expect(t, len(oldFields) == 0) expect(t, len(newFields) == 0) oldObject, oldFields, newFields = c.Set("str", str2, nil, nil) expect(t, oldObject == str1) expect(t, len(oldFields) == 0) expect(t, len(newFields) == 0) }) t.Run("AddPoint", func(t *testing.T) { c := New() point1 := PO(-112.1, 33.1) oldObject, oldFields, newFields := c.Set("point", point1, nil, nil) expect(t, oldObject == nil) expect(t, len(oldFields) == 0) expect(t, len(newFields) == 0) }) t.Run("UpdatePoint", func(t *testing.T) { c := New() point1 := PO(-112.1, 33.1) point2 := PO(-112.2, 33.2) oldObject, oldFields, newFields := c.Set("point", point1, nil, nil) expect(t, oldObject == nil) expect(t, len(oldFields) == 0) expect(t, len(newFields) == 0) oldObject, oldFields, newFields = c.Set("point", point2, nil, nil) expect(t, oldObject == point1) expect(t, len(oldFields) == 0) expect(t, len(newFields) == 0) }) t.Run("Fields", func(t *testing.T) { c := New() str1 := String("hello") fNames := []string{"a", "b", "c"} fValues := []float64{1, 2, 3} oldObj, oldFlds, newFlds := c.Set("str", str1, fNames, fValues) expect(t, oldObj == nil) expect(t, len(oldFlds) == 0) expect(t, reflect.DeepEqual(newFlds, fValues)) str2 := String("hello") fNames = []string{"d", "e", "f"} fValues = []float64{4, 5, 6} oldObj, oldFlds, newFlds = c.Set("str", str2, fNames, fValues) expect(t, oldObj == str1) expect(t, reflect.DeepEqual(oldFlds, []float64{1, 2, 3})) expect(t, reflect.DeepEqual(newFlds, []float64{1, 2, 3, 4, 5, 6})) fValues = []float64{7, 8, 9, 10, 11, 12} oldObj, oldFlds, newFlds = c.Set("str", str1, nil, fValues) expect(t, oldObj == str2) expect(t, reflect.DeepEqual(oldFlds, []float64{1, 2, 3, 4, 5, 6})) expect(t, reflect.DeepEqual(newFlds, []float64{7, 8, 9, 10, 11, 12})) }) t.Run("Delete", func(t *testing.T) { c := New() c.Set("1", String("1"), nil, nil) c.Set("2", String("2"), nil, nil) c.Set("3", PO(1, 2), nil, nil) expect(t, c.Count() == 3) expect(t, c.StringCount() == 2) expect(t, c.PointCount() == 1) expect(t, bounds(c) == geometry.Rect{ Min: geometry.Point{X: 1, Y: 2}, Max: geometry.Point{X: 1, Y: 2}}) var v geojson.Object var ok bool var flds []float64 var updated bool var updateCount int v, _, ok = c.Delete("2") expect(t, v.String() == "2") expect(t, ok) expect(t, c.Count() == 2) expect(t, c.StringCount() == 1) expect(t, c.PointCount() == 1) v, _, ok = c.Delete("1") expect(t, v.String() == "1") expect(t, ok) expect(t, c.Count() == 1) expect(t, c.StringCount() == 0) expect(t, c.PointCount() == 1) expect(t, len(c.FieldMap()) == 0) v, flds, updated, ok = c.SetField("3", "hello", 123) expect(t, ok) expect(t, reflect.DeepEqual(flds, []float64{123})) expect(t, updated) expect(t, c.FieldMap()["hello"] == 0) v, flds, updated, ok = c.SetField("3", "hello", 1234) expect(t, ok) expect(t, reflect.DeepEqual(flds, []float64{1234})) expect(t, updated) v, flds, updated, ok = c.SetField("3", "hello", 1234) expect(t, ok) expect(t, reflect.DeepEqual(flds, []float64{1234})) expect(t, !updated) v, flds, updateCount, ok = c.SetFields("3", []string{"planet", "world"}, []float64{55, 66}) expect(t, ok) expect(t, reflect.DeepEqual(flds, []float64{1234, 55, 66})) expect(t, updateCount == 2) expect(t, c.FieldMap()["hello"] == 0) expect(t, c.FieldMap()["planet"] == 1) expect(t, c.FieldMap()["world"] == 2) v, _, ok = c.Delete("3") expect(t, v.String() == `{"type":"Point","coordinates":[1,2]}`) expect(t, ok) expect(t, c.Count() == 0) expect(t, c.StringCount() == 0) expect(t, c.PointCount() == 0) v, _, ok = c.Delete("3") expect(t, v == nil) expect(t, !ok) expect(t, c.Count() == 0) expect(t, bounds(c) == geometry.Rect{}) v, _, ok = c.Get("3") expect(t, v == nil) expect(t, !ok) _, _, _, ok = c.SetField("3", "hello", 123) expect(t, !ok) _, _, _, ok = c.SetFields("3", []string{"hello"}, []float64{123}) expect(t, !ok) expect(t, c.TotalWeight() == 0) expect(t, c.FieldMap()["hello"] == 0) expect(t, c.FieldMap()["planet"] == 1) expect(t, c.FieldMap()["world"] == 2) expect(t, reflect.DeepEqual( c.FieldArr(), []string{"hello", "planet", "world"}), ) }) } func TestCollectionScan(t *testing.T) { N := 256 c := New() for _, i := range rand.Perm(N) { id := fmt.Sprintf("%04d", i) c.Set(id, String(id), []string{"ex"}, []float64{float64(i)}) } var n int var prevID string c.Scan(false, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, id > prevID) } expect(t, id == fmt.Sprintf("%04d", int(fields[0]))) n++ prevID = id return true }) expect(t, n == c.Count()) n = 0 c.Scan(true, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, id < prevID) } expect(t, id == fmt.Sprintf("%04d", int(fields[0]))) n++ prevID = id return true }) expect(t, n == c.Count()) n = 0 c.ScanRange("0060", "0070", false, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, id > prevID) } expect(t, id == fmt.Sprintf("%04d", int(fields[0]))) n++ prevID = id return true }) expect(t, n == 10) n = 0 c.ScanRange("0070", "0060", true, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, id < prevID) } expect(t, id == fmt.Sprintf("%04d", int(fields[0]))) n++ prevID = id return true }) expect(t, n == 10) n = 0 c.ScanGreaterOrEqual("0070", true, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, id < prevID) } expect(t, id == fmt.Sprintf("%04d", int(fields[0]))) n++ prevID = id return true }) expect(t, n == 71) n = 0 c.ScanGreaterOrEqual("0070", false, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, id > prevID) } expect(t, id == fmt.Sprintf("%04d", int(fields[0]))) n++ prevID = id return true }) expect(t, n == c.Count()-70) } func TestCollectionSearch(t *testing.T) { N := 256 c := New() for i, j := range rand.Perm(N) { id := fmt.Sprintf("%04d", j) ex := fmt.Sprintf("%04d", i) c.Set(id, String(ex), []string{"i", "j"}, []float64{float64(i), float64(j)}) } var n int var prevValue string c.SearchValues(false, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, obj.String() > prevValue) } expect(t, id == fmt.Sprintf("%04d", int(fields[1]))) n++ prevValue = obj.String() return true }) expect(t, n == c.Count()) n = 0 c.SearchValues(true, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, obj.String() < prevValue) } expect(t, id == fmt.Sprintf("%04d", int(fields[1]))) n++ prevValue = obj.String() return true }) expect(t, n == c.Count()) n = 0 c.SearchValuesRange("0060", "0070", false, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, obj.String() > prevValue) } expect(t, id == fmt.Sprintf("%04d", int(fields[1]))) n++ prevValue = obj.String() return true }) expect(t, n == 10) n = 0 c.SearchValuesRange("0070", "0060", true, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { if n > 0 { expect(t, obj.String() < prevValue) } expect(t, id == fmt.Sprintf("%04d", int(fields[1]))) n++ prevValue = obj.String() return true }) expect(t, n == 10) } func TestCollectionWeight(t *testing.T) { c := New() c.Set("1", String("1"), nil, nil) expect(t, c.TotalWeight() > 0) c.Delete("1") expect(t, c.TotalWeight() == 0) c.Set("1", String("1"), []string{"a", "b", "c"}, []float64{1, 2, 3}, ) expect(t, c.TotalWeight() > 0) c.Delete("1") expect(t, c.TotalWeight() == 0) c.Set("1", String("1"), []string{"a", "b", "c"}, []float64{1, 2, 3}, ) c.Set("2", String("2"), []string{"d", "e", "f"}, []float64{4, 5, 6}, ) c.Set("1", String("1"), []string{"d", "e", "f"}, []float64{4, 5, 6}, ) c.Delete("1") c.Delete("2") expect(t, c.TotalWeight() == 0) } func TestSpatialSearch(t *testing.T) { json := ` {"type":"FeatureCollection","features":[ {"type":"Feature","id":"p1","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Point","coordinates":[-71.4743041992187,42.51867517417283]}}, {"type":"Feature","id":"p2","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Point","coordinates":[-71.4056396484375,42.50197174319114]}}, {"type":"Feature","id":"p3","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Point","coordinates":[-71.4619445800781,42.49437779897246]}}, {"type":"Feature","id":"p4","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Point","coordinates":[-71.4337921142578,42.53891577257117]}}, {"type":"Feature","id":"r1","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Polygon","coordinates":[[[-71.4279556274414,42.48804880765346],[-71.37439727783203,42.48804880765346],[-71.37439727783203,42.52322988064187],[-71.4279556274414,42.52322988064187],[-71.4279556274414,42.48804880765346]]]}}, {"type":"Feature","id":"r2","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Polygon","coordinates":[[[-71.4825439453125,42.53588010092859],[-71.45027160644531,42.53588010092859],[-71.45027160644531,42.55839115400447],[-71.4825439453125,42.55839115400447],[-71.4825439453125,42.53588010092859]]]}}, {"type":"Feature","id":"r3","properties":{"marker-color":"#962d28","stroke":"#962d28","fill":"#962d28"},"geometry":{"type":"Polygon","coordinates": [[[-71.4111328125,42.53512115995963],[-71.3833236694336,42.53512115995963],[-71.3833236694336,42.54953946116446],[-71.4111328125,42.54953946116446],[-71.4111328125,42.53512115995963]]]}}, {"type":"Feature","id":"q1","properties":{},"geometry":{"type":"Polygon","coordinates":[[[-71.55258178710938,42.51361399979923],[-71.42074584960938,42.51361399979923],[-71.42074584960938,42.59100512331456],[-71.55258178710938,42.59100512331456],[-71.55258178710938,42.51361399979923]]]}}, {"type":"Feature","id":"q2","properties":{},"geometry":{"type":"Polygon","coordinates":[[[-71.52992248535156,42.48121277771616],[-71.36375427246092,42.48121277771616],[-71.36375427246092,42.57786045892046],[-71.52992248535156,42.57786045892046],[-71.52992248535156,42.48121277771616]]]}}, {"type":"Feature","id":"q3","properties":{},"geometry":{"type":"Polygon","coordinates":[[[-71.49490356445312,42.56673588590953],[-71.52236938476562,42.47462922809497],[-71.42898559570312,42.464499337722344],[-71.43241882324219,42.522217752342236],[-71.37954711914061,42.56420729713456],[-71.49490356445312,42.56673588590953]]]}}, {"type":"Feature","id":"q4","properties":{},"geometry":{"type":"Point","coordinates": [-71.46366119384766,42.54043355305221]}} ]} ` p1, _ := geojson.Parse(gjson.Get(json, `features.#[id=="p1"]`).Raw, nil) p2, _ := geojson.Parse(gjson.Get(json, `features.#[id=="p2"]`).Raw, nil) p3, _ := geojson.Parse(gjson.Get(json, `features.#[id=="p3"]`).Raw, nil) p4, _ := geojson.Parse(gjson.Get(json, `features.#[id=="p4"]`).Raw, nil) r1, _ := geojson.Parse(gjson.Get(json, `features.#[id=="r1"]`).Raw, nil) r2, _ := geojson.Parse(gjson.Get(json, `features.#[id=="r2"]`).Raw, nil) r3, _ := geojson.Parse(gjson.Get(json, `features.#[id=="r3"]`).Raw, nil) q1, _ := geojson.Parse(gjson.Get(json, `features.#[id=="q1"]`).Raw, nil) q2, _ := geojson.Parse(gjson.Get(json, `features.#[id=="q2"]`).Raw, nil) q3, _ := geojson.Parse(gjson.Get(json, `features.#[id=="q3"]`).Raw, nil) q4, _ := geojson.Parse(gjson.Get(json, `features.#[id=="q4"]`).Raw, nil) c := New() c.Set("p1", p1, nil, nil) c.Set("p2", p2, nil, nil) c.Set("p3", p3, nil, nil) c.Set("p4", p4, nil, nil) c.Set("r1", r1, nil, nil) c.Set("r2", r2, nil, nil) c.Set("r3", r3, nil, nil) var n int n = 0 c.Within(q1, 0, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return true }, ) expect(t, n == 3) n = 0 c.Within(q2, 0, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return true }, ) expect(t, n == 7) n = 0 c.Within(q3, 0, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return true }, ) expect(t, n == 4) n = 0 c.Intersects(q1, 0, nil, nil, func(_ string, _ geojson.Object, _ []float64) bool { n++ return true }, ) expect(t, n == 4) n = 0 c.Intersects(q2, 0, nil, nil, func(_ string, _ geojson.Object, _ []float64) bool { n++ return true }, ) expect(t, n == 7) n = 0 c.Intersects(q3, 0, nil, nil, func(_ string, _ geojson.Object, _ []float64) bool { n++ return true }, ) expect(t, n == 5) n = 0 c.Intersects(q3, 0, nil, nil, func(_ string, _ geojson.Object, _ []float64) bool { n++ return n <= 1 }, ) expect(t, n == 2) var items []geojson.Object exitems := []geojson.Object{ r2, p1, p4, r1, p3, r3, p2, } c.Nearby(q4, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { items = append(items, obj) return true }, ) expect(t, len(items) == 7) expect(t, reflect.DeepEqual(items, exitems)) } func TestCollectionSparse(t *testing.T) { rect := geojson.NewRect(geometry.Rect{ Min: geometry.Point{X: -71.598930, Y: 42.4586739}, Max: geometry.Point{X: -71.37302, Y: 42.607937}, }) N := 10000 c := New() r := rect.Rect() for i := 0; i < N; i++ { x := (r.Max.X-r.Min.X)*rand.Float64() + r.Min.X y := (r.Max.Y-r.Min.Y)*rand.Float64() + r.Min.Y point := PO(x, y) c.Set(fmt.Sprintf("%d", i), point, nil, nil) } var n int n = 0 c.Within(rect, 1, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return true }, ) expect(t, n == 4) n = 0 c.Within(rect, 2, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return true }, ) expect(t, n == 16) n = 0 c.Within(rect, 3, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return true }, ) expect(t, n == 64) n = 0 c.Within(rect, 3, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { n++ return n <= 30 }, ) expect(t, n == 31) n = 0 c.Intersects(rect, 3, nil, nil, func(id string, _ geojson.Object, _ []float64) bool { n++ return true }, ) expect(t, n == 64) n = 0 c.Intersects(rect, 3, nil, nil, func(id string, _ geojson.Object, _ []float64) bool { n++ return n <= 30 }, ) expect(t, n == 31) } func testCollectionVerifyContents(t *testing.T, c *Collection, objs map[string]geojson.Object) { for id, o2 := range objs { o1, _, ok := c.Get(id) if !ok { t.Fatalf("ok[%s] = false, expect true", id) } j1 := string(o1.AppendJSON(nil)) j2 := string(o2.AppendJSON(nil)) if j1 != j2 { t.Fatalf("j1 == %s, expect %s", j1, j2) } } } func TestManyCollections(t *testing.T) { colsM := make(map[string]*Collection) cols := 100 objs := 1000 k := 0 for i := 0; i < cols; i++ { key := strconv.FormatInt(int64(i), 10) for j := 0; j < objs; j++ { id := strconv.FormatInt(int64(j), 10) p := geometry.Point{ X: rand.Float64()*360 - 180, Y: rand.Float64()*180 - 90, } obj := geojson.Object(PO(p.X, p.Y)) col, ok := colsM[key] if !ok { col = New() colsM[key] = col } col.Set(id, obj, nil, nil) k++ } } col := colsM["13"] //println(col.Count()) bbox := geometry.Rect{ Min: geometry.Point{X: -180, Y: 30}, Max: geometry.Point{X: 34, Y: 100}, } col.geoSearch(bbox, func(id string, obj geojson.Object, fields []float64) bool { //println(id) return true }) } type testPointItem struct { id string object geojson.Object fields []float64 } func makeBenchFields(nFields int) []float64 { if nFields == 0 { return nil } return make([]float64, nFields) } func BenchmarkInsert_Fields(t *testing.B) { benchmarkInsert(t, 1) } func BenchmarkInsert_NoFields(t *testing.B) { benchmarkInsert(t, 0) } func benchmarkInsert(t *testing.B, nFields int) { rand.Seed(time.Now().UnixNano()) items := make([]testPointItem, t.N) for i := 0; i < t.N; i++ { items[i] = testPointItem{ fmt.Sprintf("%d", i), PO(rand.Float64()*360-180, rand.Float64()*180-90), makeBenchFields(nFields), } } col := New() t.ResetTimer() for i := 0; i < t.N; i++ { col.Set(items[i].id, items[i].object, nil, items[i].fields) } } func BenchmarkReplace_Fields(t *testing.B) { benchmarkReplace(t, 1) } func BenchmarkReplace_NoFields(t *testing.B) { benchmarkReplace(t, 0) } func benchmarkReplace(t *testing.B, nFields int) { rand.Seed(time.Now().UnixNano()) items := make([]testPointItem, t.N) for i := 0; i < t.N; i++ { items[i] = testPointItem{ fmt.Sprintf("%d", i), PO(rand.Float64()*360-180, rand.Float64()*180-90), makeBenchFields(nFields), } } col := New() for i := 0; i < t.N; i++ { col.Set(items[i].id, items[i].object, nil, items[i].fields) } t.ResetTimer() for _, i := range rand.Perm(t.N) { o, _, _ := col.Set(items[i].id, items[i].object, nil, nil) if o != items[i].object { t.Fatal("shoot!") } } } func BenchmarkGet_Fields(t *testing.B) { benchmarkGet(t, 1) } func BenchmarkGet_NoFields(t *testing.B) { benchmarkGet(t, 0) } func benchmarkGet(t *testing.B, nFields int) { rand.Seed(time.Now().UnixNano()) items := make([]testPointItem, t.N) for i := 0; i < t.N; i++ { items[i] = testPointItem{ fmt.Sprintf("%d", i), PO(rand.Float64()*360-180, rand.Float64()*180-90), makeBenchFields(nFields), } } col := New() for i := 0; i < t.N; i++ { col.Set(items[i].id, items[i].object, nil, items[i].fields) } t.ResetTimer() for _, i := range rand.Perm(t.N) { o, _, _ := col.Get(items[i].id) if o != items[i].object { t.Fatal("shoot!") } } } func BenchmarkRemove_Fields(t *testing.B) { benchmarkRemove(t, 1) } func BenchmarkRemove_NoFields(t *testing.B) { benchmarkRemove(t, 0) } func benchmarkRemove(t *testing.B, nFields int) { rand.Seed(time.Now().UnixNano()) items := make([]testPointItem, t.N) for i := 0; i < t.N; i++ { items[i] = testPointItem{ fmt.Sprintf("%d", i), PO(rand.Float64()*360-180, rand.Float64()*180-90), makeBenchFields(nFields), } } col := New() for i := 0; i < t.N; i++ { col.Set(items[i].id, items[i].object, nil, items[i].fields) } t.ResetTimer() for _, i := range rand.Perm(t.N) { o, _, _ := col.Delete(items[i].id) if o != items[i].object { t.Fatal("shoot!") } } } func BenchmarkScan_Fields(t *testing.B) { benchmarkScan(t, 1) } func BenchmarkScan_NoFields(t *testing.B) { benchmarkScan(t, 0) } func benchmarkScan(t *testing.B, nFields int) { rand.Seed(time.Now().UnixNano()) items := make([]testPointItem, t.N) for i := 0; i < t.N; i++ { items[i] = testPointItem{ fmt.Sprintf("%d", i), PO(rand.Float64()*360-180, rand.Float64()*180-90), makeBenchFields(nFields), } } col := New() for i := 0; i < t.N; i++ { col.Set(items[i].id, items[i].object, nil, items[i].fields) } t.ResetTimer() for i := 0; i < t.N; i++ { var scanIteration int col.Scan(true, nil, nil, func(id string, obj geojson.Object, fields []float64) bool { scanIteration++ return scanIteration <= 500 }) } }