1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278
|
package rtree
import (
"math"
"sync"
"github.com/tidwall/rtree/base"
)
type Iterator func(item Item) bool
type Item interface {
Rect(ctx interface{}) (min []float64, max []float64)
}
type RTree struct {
dims int
maxEntries int
ctx interface{}
trs []*base.RTree
used int
}
func New(ctx interface{}) *RTree {
tr := &RTree{
ctx: ctx,
dims: 20,
maxEntries: 13,
}
tr.trs = make([]*base.RTree, 20)
return tr
}
func (tr *RTree) Insert(item Item) {
if item == nil {
panic("nil item")
}
min, max := item.Rect(tr.ctx)
if len(min) != len(max) {
return // just return
panic("invalid item rectangle")
}
if len(min) < 1 || len(min) > len(tr.trs) {
return // just return
panic("invalid dimension")
}
btr := tr.trs[len(min)-1]
if btr == nil {
btr = base.New(len(min), tr.maxEntries)
tr.trs[len(min)-1] = btr
tr.used++
}
amin := make([]float64, len(min))
amax := make([]float64, len(max))
for i := 0; i < len(min); i++ {
amin[i], amax[i] = min[i], max[i]
}
btr.Insert(amin, amax, item)
}
func (tr *RTree) Remove(item Item) {
if item == nil {
panic("nil item")
}
min, max := item.Rect(tr.ctx)
if len(min) != len(max) {
return // just return
panic("invalid item rectangle")
}
if len(min) < 1 || len(min) > len(tr.trs) {
return // just return
panic("invalid dimension")
}
btr := tr.trs[len(min)-1]
if btr == nil {
return
}
amin := make([]float64, len(min))
amax := make([]float64, len(max))
for i := 0; i < len(min); i++ {
amin[i], amax[i] = min[i], max[i]
}
btr.Remove(amin, amax, item)
if btr.IsEmpty() {
tr.trs[len(min)-1] = nil
tr.used--
}
}
func (tr *RTree) Reset() {
for i := 0; i < len(tr.trs); i++ {
tr.trs[i] = nil
}
tr.used = 0
}
func (tr *RTree) Count() int {
var count int
for _, btr := range tr.trs {
if btr != nil {
count += btr.Count()
}
}
return count
}
func (tr *RTree) Search(bounds Item, iter Iterator) {
if bounds == nil {
panic("nil bounds being used for search")
}
min, max := bounds.Rect(tr.ctx)
if len(min) != len(max) {
return // just return
panic("invalid item rectangle")
}
if len(min) < 1 || len(min) > len(tr.trs) {
return // just return
panic("invalid dimension")
}
used := tr.used
for i, btr := range tr.trs {
if used == 0 {
break
}
if btr != nil {
if !search(btr, min, max, i+1, iter) {
return
}
used--
}
}
}
func search(btr *base.RTree, min, max []float64, dims int, iter Iterator) bool {
amin := make([]float64, dims)
amax := make([]float64, dims)
for i := 0; i < dims; i++ {
if i < len(min) {
amin[i] = min[i]
amax[i] = max[i]
} else {
amin[i] = math.Inf(-1)
amax[i] = math.Inf(+1)
}
}
var ended bool
btr.Search(amin, amax, func(item interface{}) bool {
if !iter(item.(Item)) {
ended = true
return false
}
return true
})
return !ended
}
func (tr *RTree) KNN(bounds Item, center bool, iter func(item Item, dist float64) bool) {
if bounds == nil {
panic("nil bounds being used for search")
}
min, max := bounds.Rect(tr.ctx)
if len(min) != len(max) {
return // just return
panic("invalid item rectangle")
}
if len(min) < 1 || len(min) > len(tr.trs) {
return // just return
panic("invalid dimension")
}
if tr.used == 0 {
return
}
if tr.used == 1 {
for i, btr := range tr.trs {
if btr != nil {
knn(btr, min, max, center, i+1, func(item interface{}, dist float64) bool {
return iter(item.(Item), dist)
})
break
}
}
return
}
type queueT struct {
done bool
step int
item Item
dist float64
}
var mu sync.Mutex
var ended bool
queues := make(map[int][]queueT)
cond := sync.NewCond(&mu)
for i, btr := range tr.trs {
if btr != nil {
dims := i + 1
mu.Lock()
queues[dims] = []queueT{}
cond.Signal()
mu.Unlock()
go func(dims int, btr *base.RTree) {
knn(btr, min, max, center, dims, func(item interface{}, dist float64) bool {
mu.Lock()
if ended {
mu.Unlock()
return false
}
queues[dims] = append(queues[dims], queueT{item: item.(Item), dist: dist})
cond.Signal()
mu.Unlock()
return true
})
mu.Lock()
queues[dims] = append(queues[dims], queueT{done: true})
cond.Signal()
mu.Unlock()
}(dims, btr)
}
}
mu.Lock()
for {
ready := true
for i := range queues {
if len(queues[i]) == 0 {
ready = false
break
}
if queues[i][0].done {
delete(queues, i)
}
}
if len(queues) == 0 {
break
}
if ready {
var j int
var minDist float64
var minItem Item
var minQueue int
for i := range queues {
if j == 0 || queues[i][0].dist < minDist {
minDist = queues[i][0].dist
minItem = queues[i][0].item
minQueue = i
}
}
queues[minQueue] = queues[minQueue][1:]
if !iter(minItem, minDist) {
ended = true
break
}
continue
}
cond.Wait()
}
mu.Unlock()
}
func knn(btr *base.RTree, min, max []float64, center bool, dims int, iter func(item interface{}, dist float64) bool) bool {
amin := make([]float64, dims)
amax := make([]float64, dims)
for i := 0; i < dims; i++ {
if i < len(min) {
amin[i] = min[i]
amax[i] = max[i]
} else {
amin[i] = math.Inf(-1)
amax[i] = math.Inf(+1)
}
}
var ended bool
btr.KNN(amin, amax, center, func(item interface{}, dist float64) bool {
if !iter(item.(Item), dist) {
ended = true
return false
}
return true
})
return !ended
}
|