mirror of https://github.com/tidwall/tile38.git
762 lines
18 KiB
Go
762 lines
18 KiB
Go
package collection
|
|
|
|
import (
|
|
"runtime"
|
|
|
|
"github.com/tidwall/btree"
|
|
"github.com/tidwall/geoindex"
|
|
"github.com/tidwall/geojson"
|
|
"github.com/tidwall/geojson/geo"
|
|
"github.com/tidwall/geojson/geometry"
|
|
"github.com/tidwall/rbang"
|
|
"github.com/tidwall/tile38/internal/deadline"
|
|
"github.com/tidwall/tinybtree"
|
|
)
|
|
|
|
// yieldStep forces the iterator to yield goroutine every 255 steps.
|
|
const yieldStep = 255
|
|
|
|
// Cursor allows for quickly paging through Scan, Within, Intersects, and Nearby
|
|
type Cursor interface {
|
|
Offset() uint64
|
|
Step(count uint64)
|
|
}
|
|
|
|
type itemT struct {
|
|
id string
|
|
obj geojson.Object
|
|
}
|
|
|
|
func (item *itemT) Less(other btree.Item, ctx interface{}) bool {
|
|
value1 := item.obj.String()
|
|
value2 := other.(*itemT).obj.String()
|
|
if value1 < value2 {
|
|
return true
|
|
}
|
|
if value1 > value2 {
|
|
return false
|
|
}
|
|
// the values match so we'll compare IDs, which are always unique.
|
|
return item.id < other.(*itemT).id
|
|
}
|
|
|
|
// Collection represents a collection of geojson objects.
|
|
type Collection struct {
|
|
items tinybtree.BTree // items sorted by keys
|
|
index *geoindex.Index // items geospatially indexed
|
|
values *btree.BTree // items sorted by value+key
|
|
fieldMap map[string]int
|
|
fieldArr []string
|
|
fieldValues map[string][]float64
|
|
weight int
|
|
points int
|
|
objects int // geometry count
|
|
nobjects int // non-geometry count
|
|
}
|
|
|
|
var counter uint64
|
|
|
|
// New creates an empty collection
|
|
func New() *Collection {
|
|
col := &Collection{
|
|
index: geoindex.Wrap(&rbang.RTree{}),
|
|
values: btree.New(32, nil),
|
|
fieldMap: make(map[string]int),
|
|
fieldArr: make([]string, 0),
|
|
}
|
|
return col
|
|
}
|
|
|
|
func (c *Collection) setFieldValues(id string, values []float64) {
|
|
if c.fieldValues == nil {
|
|
c.fieldValues = make(map[string][]float64)
|
|
}
|
|
c.fieldValues[id] = values
|
|
}
|
|
func (c *Collection) getFieldValues(id string) (values []float64) {
|
|
return c.fieldValues[id]
|
|
}
|
|
func (c *Collection) deleteFieldValues(id string) {
|
|
if c.fieldValues != nil {
|
|
delete(c.fieldValues, id)
|
|
}
|
|
}
|
|
|
|
// Count returns the number of objects in collection.
|
|
func (c *Collection) Count() int {
|
|
return c.objects + c.nobjects
|
|
}
|
|
|
|
// StringCount returns the number of string values.
|
|
func (c *Collection) StringCount() int {
|
|
return c.nobjects
|
|
}
|
|
|
|
// PointCount returns the number of points (lat/lon coordinates) in collection.
|
|
func (c *Collection) PointCount() int {
|
|
return c.points
|
|
}
|
|
|
|
// TotalWeight calculates the in-memory cost of the collection in bytes.
|
|
func (c *Collection) TotalWeight() int {
|
|
return c.weight
|
|
}
|
|
|
|
// Bounds returns the bounds of all the items in the collection.
|
|
func (c *Collection) Bounds() (minX, minY, maxX, maxY float64) {
|
|
min, max := c.index.Bounds()
|
|
if len(min) >= 2 && len(max) >= 2 {
|
|
return min[0], min[1], max[0], max[1]
|
|
}
|
|
return
|
|
}
|
|
|
|
func objIsSpatial(obj geojson.Object) bool {
|
|
_, ok := obj.(geojson.Spatial)
|
|
return ok
|
|
}
|
|
|
|
func (c *Collection) objWeight(item *itemT) int {
|
|
var weight int
|
|
if objIsSpatial(item.obj) {
|
|
weight = item.obj.NumPoints() * 16
|
|
} else {
|
|
weight = len(item.obj.String())
|
|
}
|
|
return weight + len(c.getFieldValues(item.id))*8 + len(item.id)
|
|
}
|
|
|
|
func (c *Collection) indexDelete(item *itemT) {
|
|
if !item.obj.Empty() {
|
|
rect := item.obj.Rect()
|
|
c.index.Delete(
|
|
[2]float64{rect.Min.X, rect.Min.Y},
|
|
[2]float64{rect.Max.X, rect.Max.Y},
|
|
item)
|
|
}
|
|
}
|
|
|
|
func (c *Collection) indexInsert(item *itemT) {
|
|
if !item.obj.Empty() {
|
|
rect := item.obj.Rect()
|
|
c.index.Insert(
|
|
[2]float64{rect.Min.X, rect.Min.Y},
|
|
[2]float64{rect.Max.X, rect.Max.Y},
|
|
item)
|
|
}
|
|
}
|
|
|
|
// Set adds or replaces an object in the collection and returns the fields
|
|
// array. If an item with the same id is already in the collection then the
|
|
// new item will adopt the old item's fields.
|
|
// The fields argument is optional.
|
|
// The return values are the old object, the old fields, and the new fields
|
|
func (c *Collection) Set(
|
|
id string, obj geojson.Object, fields []string, values []float64,
|
|
) (
|
|
oldObject geojson.Object, oldFields []float64, newFields []float64,
|
|
) {
|
|
newItem := &itemT{id: id, obj: obj}
|
|
|
|
// add the new item to main btree and remove the old one if needed
|
|
oldItem, ok := c.items.Set(id, newItem)
|
|
if ok {
|
|
oldItem := oldItem.(*itemT)
|
|
// the old item was removed, now let's remove it from the rtree/btree.
|
|
if objIsSpatial(oldItem.obj) {
|
|
c.indexDelete(oldItem)
|
|
c.objects--
|
|
} else {
|
|
c.values.Delete(oldItem)
|
|
c.nobjects--
|
|
}
|
|
|
|
// decrement the point count
|
|
c.points -= oldItem.obj.NumPoints()
|
|
|
|
// decrement the weights
|
|
c.weight -= c.objWeight(oldItem)
|
|
|
|
// references
|
|
oldObject = oldItem.obj
|
|
oldFields = c.getFieldValues(id)
|
|
newFields = oldFields
|
|
}
|
|
// insert the new item into the rtree or strings tree.
|
|
if objIsSpatial(newItem.obj) {
|
|
c.indexInsert(newItem)
|
|
c.objects++
|
|
} else {
|
|
c.values.ReplaceOrInsert(newItem)
|
|
c.nobjects++
|
|
}
|
|
|
|
// increment the point count
|
|
c.points += newItem.obj.NumPoints()
|
|
|
|
// add the new weights
|
|
c.weight += c.objWeight(newItem)
|
|
|
|
if fields == nil {
|
|
if len(values) > 0 {
|
|
// directly set the field values, update weight
|
|
c.weight -= len(newFields) * 8
|
|
newFields = values
|
|
c.setFieldValues(id, newFields)
|
|
c.weight += len(newFields) * 8
|
|
}
|
|
} else {
|
|
// map field name to value
|
|
for i, field := range fields {
|
|
c.setField(newItem, field, values[i])
|
|
}
|
|
newFields = c.getFieldValues(id)
|
|
}
|
|
return oldObject, oldFields, newFields
|
|
}
|
|
|
|
// Delete removes an object and returns it.
|
|
// If the object does not exist then the 'ok' return value will be false.
|
|
func (c *Collection) Delete(id string) (
|
|
obj geojson.Object, fields []float64, ok bool,
|
|
) {
|
|
oldItemV, ok := c.items.Delete(id)
|
|
if !ok {
|
|
return nil, nil, false
|
|
}
|
|
oldItem := oldItemV.(*itemT)
|
|
if objIsSpatial(oldItem.obj) {
|
|
if !oldItem.obj.Empty() {
|
|
c.indexDelete(oldItem)
|
|
}
|
|
c.objects--
|
|
} else {
|
|
c.values.Delete(oldItem)
|
|
c.nobjects--
|
|
}
|
|
c.weight -= c.objWeight(oldItem)
|
|
c.points -= oldItem.obj.NumPoints()
|
|
|
|
fields = c.getFieldValues(id)
|
|
c.deleteFieldValues(id)
|
|
return oldItem.obj, fields, true
|
|
}
|
|
|
|
// Get returns an object.
|
|
// If the object does not exist then the 'ok' return value will be false.
|
|
func (c *Collection) Get(id string) (
|
|
obj geojson.Object, fields []float64, ok bool,
|
|
) {
|
|
itemV, ok := c.items.Get(id)
|
|
if !ok {
|
|
return nil, nil, false
|
|
}
|
|
item := itemV.(*itemT)
|
|
return item.obj, c.getFieldValues(id), true
|
|
}
|
|
|
|
// SetField set a field value for an object and returns that object.
|
|
// If the object does not exist then the 'ok' return value will be false.
|
|
func (c *Collection) SetField(id, field string, value float64) (
|
|
obj geojson.Object, fields []float64, updated bool, ok bool,
|
|
) {
|
|
itemV, ok := c.items.Get(id)
|
|
if !ok {
|
|
return nil, nil, false, false
|
|
}
|
|
item := itemV.(*itemT)
|
|
updated = c.setField(item, field, value)
|
|
return item.obj, c.getFieldValues(id), updated, true
|
|
}
|
|
|
|
// SetFields is similar to SetField, just setting multiple fields at once
|
|
func (c *Collection) SetFields(
|
|
id string, inFields []string, inValues []float64,
|
|
) (obj geojson.Object, fields []float64, updatedCount int, ok bool) {
|
|
itemV, ok := c.items.Get(id)
|
|
if !ok {
|
|
return nil, nil, 0, false
|
|
}
|
|
item := itemV.(*itemT)
|
|
for idx, field := range inFields {
|
|
if c.setField(item, field, inValues[idx]) {
|
|
updatedCount++
|
|
}
|
|
}
|
|
return item.obj, c.getFieldValues(id), updatedCount, true
|
|
}
|
|
|
|
func (c *Collection) setField(item *itemT, field string, value float64) (
|
|
updated bool,
|
|
) {
|
|
idx, ok := c.fieldMap[field]
|
|
if !ok {
|
|
idx = len(c.fieldMap)
|
|
c.fieldMap[field] = idx
|
|
c.addToFieldArr(field)
|
|
}
|
|
fields := c.getFieldValues(item.id)
|
|
c.weight -= len(fields) * 8
|
|
for idx >= len(fields) {
|
|
fields = append(fields, 0)
|
|
}
|
|
c.weight += len(fields) * 8
|
|
ovalue := fields[idx]
|
|
fields[idx] = value
|
|
c.setFieldValues(item.id, fields)
|
|
return ovalue != value
|
|
}
|
|
|
|
// FieldMap return a maps of the field names.
|
|
func (c *Collection) FieldMap() map[string]int {
|
|
return c.fieldMap
|
|
}
|
|
|
|
// FieldArr return an array representation of the field names.
|
|
func (c *Collection) FieldArr() []string {
|
|
return c.fieldArr
|
|
}
|
|
|
|
// bsearch searches array for value.
|
|
func bsearch(arr []string, val string) (index int, found bool) {
|
|
i, j := 0, len(arr)
|
|
for i < j {
|
|
h := i + (j-i)/2
|
|
if val >= arr[h] {
|
|
i = h + 1
|
|
} else {
|
|
j = h
|
|
}
|
|
}
|
|
if i > 0 && arr[i-1] >= val {
|
|
return i - 1, true
|
|
}
|
|
return i, false
|
|
}
|
|
|
|
func (c *Collection) addToFieldArr(field string) {
|
|
if index, found := bsearch(c.fieldArr, field); !found {
|
|
c.fieldArr = append(c.fieldArr, "")
|
|
copy(c.fieldArr[index+1:], c.fieldArr[index:len(c.fieldArr)-1])
|
|
c.fieldArr[index] = field
|
|
}
|
|
}
|
|
|
|
// Scan iterates though the collection ids.
|
|
func (c *Collection) Scan(
|
|
desc bool,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iterator func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var keepon = true
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
iter := func(key string, value interface{}) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
iitm := value.(*itemT)
|
|
keepon = iterator(iitm.id, iitm.obj, c.getFieldValues(iitm.id))
|
|
return keepon
|
|
}
|
|
if desc {
|
|
c.items.Reverse(iter)
|
|
} else {
|
|
c.items.Scan(iter)
|
|
}
|
|
return keepon
|
|
}
|
|
|
|
// ScanRange iterates though the collection starting with specified id.
|
|
func (c *Collection) ScanRange(
|
|
start, end string,
|
|
desc bool,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iterator func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var keepon = true
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
iter := func(key string, value interface{}) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
if !desc {
|
|
if key >= end {
|
|
return false
|
|
}
|
|
} else {
|
|
if key <= end {
|
|
return false
|
|
}
|
|
}
|
|
iitm := value.(*itemT)
|
|
keepon = iterator(iitm.id, iitm.obj, c.getFieldValues(iitm.id))
|
|
return keepon
|
|
}
|
|
|
|
if desc {
|
|
c.items.Descend(start, iter)
|
|
} else {
|
|
c.items.Ascend(start, iter)
|
|
}
|
|
return keepon
|
|
}
|
|
|
|
// SearchValues iterates though the collection values.
|
|
func (c *Collection) SearchValues(
|
|
desc bool,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iterator func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var keepon = true
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
iter := func(item btree.Item) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
iitm := item.(*itemT)
|
|
keepon = iterator(iitm.id, iitm.obj, c.getFieldValues(iitm.id))
|
|
return keepon
|
|
}
|
|
if desc {
|
|
c.values.Descend(iter)
|
|
} else {
|
|
c.values.Ascend(iter)
|
|
}
|
|
return keepon
|
|
}
|
|
|
|
// SearchValuesRange iterates though the collection values.
|
|
func (c *Collection) SearchValuesRange(start, end string, desc bool,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iterator func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var keepon = true
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
iter := func(item btree.Item) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
iitm := item.(*itemT)
|
|
keepon = iterator(iitm.id, iitm.obj, c.getFieldValues(iitm.id))
|
|
return keepon
|
|
}
|
|
if desc {
|
|
c.values.DescendRange(&itemT{obj: String(start)},
|
|
&itemT{obj: String(end)}, iter)
|
|
} else {
|
|
c.values.AscendRange(&itemT{obj: String(start)},
|
|
&itemT{obj: String(end)}, iter)
|
|
}
|
|
return keepon
|
|
}
|
|
|
|
// ScanGreaterOrEqual iterates though the collection starting with specified id.
|
|
func (c *Collection) ScanGreaterOrEqual(id string, desc bool,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iterator func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var keepon = true
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
iter := func(key string, value interface{}) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
iitm := value.(*itemT)
|
|
keepon = iterator(iitm.id, iitm.obj, c.getFieldValues(iitm.id))
|
|
return keepon
|
|
}
|
|
if desc {
|
|
c.items.Descend(id, iter)
|
|
} else {
|
|
c.items.Ascend(id, iter)
|
|
}
|
|
return keepon
|
|
}
|
|
|
|
func (c *Collection) geoSearch(
|
|
rect geometry.Rect,
|
|
iter func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
alive := true
|
|
c.index.Search(
|
|
[2]float64{rect.Min.X, rect.Min.Y},
|
|
[2]float64{rect.Max.X, rect.Max.Y},
|
|
func(_, _ [2]float64, itemv interface{}) bool {
|
|
item := itemv.(*itemT)
|
|
alive = iter(item.id, item.obj, c.getFieldValues(item.id))
|
|
return alive
|
|
},
|
|
)
|
|
return alive
|
|
}
|
|
|
|
func (c *Collection) geoSparse(
|
|
obj geojson.Object, sparse uint8,
|
|
iter func(id string, obj geojson.Object, fields []float64) (match, ok bool),
|
|
) bool {
|
|
matches := make(map[string]bool)
|
|
alive := true
|
|
c.geoSparseInner(obj.Rect(), sparse,
|
|
func(id string, o geojson.Object, fields []float64) (
|
|
match, ok bool,
|
|
) {
|
|
ok = true
|
|
if !matches[id] {
|
|
match, ok = iter(id, o, fields)
|
|
if match {
|
|
matches[id] = true
|
|
}
|
|
}
|
|
return match, ok
|
|
},
|
|
)
|
|
return alive
|
|
}
|
|
func (c *Collection) geoSparseInner(
|
|
rect geometry.Rect, sparse uint8,
|
|
iter func(id string, obj geojson.Object, fields []float64) (match, ok bool),
|
|
) bool {
|
|
if sparse > 0 {
|
|
w := rect.Max.X - rect.Min.X
|
|
h := rect.Max.Y - rect.Min.Y
|
|
quads := [4]geometry.Rect{
|
|
geometry.Rect{
|
|
Min: geometry.Point{X: rect.Min.X, Y: rect.Min.Y + h/2},
|
|
Max: geometry.Point{X: rect.Min.X + w/2, Y: rect.Max.Y},
|
|
},
|
|
geometry.Rect{
|
|
Min: geometry.Point{X: rect.Min.X + w/2, Y: rect.Min.Y + h/2},
|
|
Max: geometry.Point{X: rect.Max.X, Y: rect.Max.Y},
|
|
},
|
|
geometry.Rect{
|
|
Min: geometry.Point{X: rect.Min.X, Y: rect.Min.Y},
|
|
Max: geometry.Point{X: rect.Min.X + w/2, Y: rect.Min.Y + h/2},
|
|
},
|
|
geometry.Rect{
|
|
Min: geometry.Point{X: rect.Min.X + w/2, Y: rect.Min.Y},
|
|
Max: geometry.Point{X: rect.Max.X, Y: rect.Min.Y + h/2},
|
|
},
|
|
}
|
|
for _, quad := range quads {
|
|
if !c.geoSparseInner(quad, sparse-1, iter) {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
alive := true
|
|
c.geoSearch(rect,
|
|
func(id string, obj geojson.Object, fields []float64) bool {
|
|
match, ok := iter(id, obj, fields)
|
|
if !ok {
|
|
alive = false
|
|
return false
|
|
}
|
|
return !match
|
|
},
|
|
)
|
|
return alive
|
|
}
|
|
|
|
// Within returns all object that are fully contained within an object or
|
|
// bounding box. Set obj to nil in order to use the bounding box.
|
|
func (c *Collection) Within(
|
|
obj geojson.Object,
|
|
sparse uint8,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iter func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
if sparse > 0 {
|
|
return c.geoSparse(obj, sparse,
|
|
func(id string, o geojson.Object, fields []float64) (
|
|
match, ok bool,
|
|
) {
|
|
count++
|
|
if count <= offset {
|
|
return false, true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
if match = o.Within(obj); match {
|
|
ok = iter(id, o, fields)
|
|
}
|
|
return match, ok
|
|
},
|
|
)
|
|
}
|
|
return c.geoSearch(obj.Rect(),
|
|
func(id string, o geojson.Object, fields []float64) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
if o.Within(obj) {
|
|
return iter(id, o, fields)
|
|
}
|
|
return true
|
|
},
|
|
)
|
|
}
|
|
|
|
// Intersects returns all object that are intersect an object or bounding box.
|
|
// Set obj to nil in order to use the bounding box.
|
|
func (c *Collection) Intersects(
|
|
obj geojson.Object,
|
|
sparse uint8,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iter func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
if sparse > 0 {
|
|
return c.geoSparse(obj, sparse,
|
|
func(id string, o geojson.Object, fields []float64) (
|
|
match, ok bool,
|
|
) {
|
|
count++
|
|
if count <= offset {
|
|
return false, true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
if match = o.Intersects(obj); match {
|
|
ok = iter(id, o, fields)
|
|
}
|
|
return match, ok
|
|
},
|
|
)
|
|
}
|
|
return c.geoSearch(obj.Rect(),
|
|
func(id string, o geojson.Object, fields []float64) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
if o.Intersects(obj) {
|
|
return iter(id, o, fields)
|
|
}
|
|
return true
|
|
},
|
|
)
|
|
}
|
|
|
|
// Nearby returns the nearest neighbors
|
|
func (c *Collection) Nearby(
|
|
target geojson.Object,
|
|
cursor Cursor,
|
|
deadline *deadline.Deadline,
|
|
iter func(id string, obj geojson.Object, fields []float64) bool,
|
|
) bool {
|
|
// First look to see if there's at least one candidate in the circle's
|
|
// outer rectangle. This is a fast-fail operation.
|
|
if circle, ok := target.(*geojson.Circle); ok {
|
|
meters := circle.Meters()
|
|
if meters > 0 {
|
|
center := circle.Center()
|
|
minLat, minLon, maxLat, maxLon :=
|
|
geo.RectFromCenter(center.Y, center.X, meters)
|
|
var exists bool
|
|
c.index.Search(
|
|
[2]float64{minLon, minLat},
|
|
[2]float64{maxLon, maxLat},
|
|
func(_, _ [2]float64, itemv interface{}) bool {
|
|
exists = true
|
|
return false
|
|
},
|
|
)
|
|
if !exists {
|
|
// no candidates
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
// do the kNN operation
|
|
alive := true
|
|
center := target.Center()
|
|
var count uint64
|
|
var offset uint64
|
|
if cursor != nil {
|
|
offset = cursor.Offset()
|
|
cursor.Step(offset)
|
|
}
|
|
c.index.Nearby(
|
|
geoindex.SimpleBoxAlgo(
|
|
[2]float64{center.X, center.Y},
|
|
[2]float64{center.X, center.Y},
|
|
),
|
|
func(_, _ [2]float64, itemv interface{}, _ float64) bool {
|
|
count++
|
|
if count <= offset {
|
|
return true
|
|
}
|
|
nextStep(count, cursor, deadline)
|
|
item := itemv.(*itemT)
|
|
alive = iter(item.id, item.obj, c.getFieldValues(item.id))
|
|
return alive
|
|
},
|
|
)
|
|
return alive
|
|
}
|
|
|
|
func nextStep(step uint64, cursor Cursor, deadline *deadline.Deadline) {
|
|
if step&yieldStep == yieldStep {
|
|
runtime.Gosched()
|
|
deadline.Check()
|
|
}
|
|
if cursor != nil {
|
|
cursor.Step(1)
|
|
}
|
|
}
|