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