tile38/internal/server/fence.go

438 lines
11 KiB
Go

package server
import (
"math"
"strconv"
"time"
"github.com/tidwall/geojson"
"github.com/tidwall/geojson/geo"
"github.com/tidwall/geojson/geometry"
"github.com/tidwall/gjson"
"github.com/tidwall/tile38/internal/collection"
"github.com/tidwall/tile38/internal/glob"
)
// FenceMatch executes a fence match returns back json messages for fence detection.
func FenceMatch(hookName string, sw *scanWriter, fence *liveFenceSwitches, metas []FenceMeta, details *commandDetails) []string {
msgs := fenceMatch(hookName, sw, fence, metas, details)
if len(fence.accept) == 0 {
return msgs
}
nmsgs := make([]string, 0, len(msgs))
for _, msg := range msgs {
if fence.accept[gjson.Get(msg, "command").String()] {
nmsgs = append(nmsgs, msg)
}
}
return nmsgs
}
func appendHookDetails(b []byte, hookName string, metas []FenceMeta) []byte {
if len(hookName) > 0 {
b = append(b, `,"hook":`...)
b = appendJSONString(b, hookName)
}
if len(metas) > 0 {
b = append(b, `,"meta":{`...)
for i, meta := range metas {
if i > 0 {
b = append(b, ',')
}
b = appendJSONString(b, meta.Name)
b = append(b, ':')
b = appendJSONString(b, meta.Value)
}
b = append(b, '}')
}
return b
}
func objIsSpatial(obj geojson.Object) bool {
_, ok := obj.(geojson.Spatial)
return ok
}
func hookJSONString(hookName string, metas []FenceMeta) string {
return string(appendHookDetails(nil, hookName, metas))
}
func fenceMatch(
hookName string, sw *scanWriter, fence *liveFenceSwitches,
metas []FenceMeta, details *commandDetails,
) []string {
if details.command == "drop" {
return []string{
`{"command":"drop"` + hookJSONString(hookName, metas) +
`,"time":` + jsonTimeFormat(details.timestamp) + `}`,
}
}
if len(fence.glob) > 0 && !(len(fence.glob) == 1 && fence.glob[0] == '*') {
match, _ := glob.Match(fence.glob, details.id)
if !match {
return nil
}
}
if details.obj == nil || !objIsSpatial(details.obj) {
return nil
}
if details.command == "fset" {
sw.mu.Lock()
nofields := sw.nofields
sw.mu.Unlock()
if nofields {
return nil
}
}
if details.command == "del" {
if fence.roam.on {
if fence.roam.nearbys != nil {
delete(fence.roam.nearbys, details.id)
if len(fence.roam.nearbys) == 0 {
fence.roam.nearbys = nil
}
}
}
return []string{
`{"command":"del"` + hookJSONString(hookName, metas) +
`,"id":` + jsonString(details.id) +
`,"time":` + jsonTimeFormat(details.timestamp) + `}`,
}
}
var roamNearbys, roamFaraways []roamMatch
var detect = "outside"
if fence != nil {
if fence.roam.on {
if details.command == "set" {
roamNearbys, roamFaraways =
fenceMatchRoam(sw.c, fence, details.key,
details.id, details.obj)
}
if len(roamNearbys) == 0 && len(roamFaraways) == 0 {
return nil
}
detect = "roam"
} else {
// not using roaming
match1 := fenceMatchObject(fence, details.oldObj)
match2 := fenceMatchObject(fence, details.obj)
if match1 && match2 {
detect = "inside"
} else if match1 && !match2 {
detect = "exit"
} else if !match1 && match2 {
detect = "enter"
if details.command == "fset" {
detect = "inside"
}
} else {
if details.command != "fset" {
// Maybe the old object and new object create a line that crosses the fence.
// Must detect for that possibility.
if details.oldObj != nil {
ls := geojson.NewLineString(geometry.NewLine(
[]geometry.Point{
details.oldObj.Center(),
details.obj.Center(),
}, nil))
temp := false
if fence.cmd == "within" {
// because we are testing if the line croses the area we need to use
// "intersects" instead of "within".
fence.cmd = "intersects"
temp = true
}
if fenceMatchObject(fence, ls) {
detect = "cross"
}
if temp {
fence.cmd = "within"
}
}
}
}
}
}
if details.fmap == nil {
return nil
}
for {
if fence.detect != nil && !fence.detect[detect] {
if detect == "enter" {
detect = "inside"
continue
}
if detect == "exit" {
detect = "outside"
continue
}
return nil
}
break
}
sw.mu.Lock()
var distance float64
if fence.distance {
distance = details.obj.Distance(fence.obj)
}
sw.fmap = details.fmap
sw.fullFields = true
sw.msg.OutputType = JSON
sw.writeObject(ScanWriterParams{
id: details.id,
o: details.obj,
fields: details.fields,
noLock: true,
distance: distance,
})
if sw.wr.Len() == 0 {
sw.mu.Unlock()
return nil
}
res := sw.wr.String()
sw.wr.Reset()
if len(res) > 0 && res[0] == ',' {
res = res[1:]
}
if sw.output == outputIDs {
res = `{"id":` + string(res) + `}`
}
sw.mu.Unlock()
if fence.groups == nil {
fence.groups = make(map[string]string)
}
groupkey := details.key + ":" + details.id
var group string
var ok bool
if detect == "enter" {
group = bsonID()
fence.groups[groupkey] = group
} else if detect == "cross" {
group = bsonID()
delete(fence.groups, groupkey)
} else {
group, ok = fence.groups[groupkey]
if !ok {
group = bsonID()
fence.groups[groupkey] = group
}
}
var msgs []string
if fence.detect == nil || fence.detect[detect] {
if len(res) > 0 && res[0] == '{' {
msgs = append(msgs, makemsg(details.command, group, detect,
hookName, metas, details.key, details.timestamp, res[1:]))
} else {
msgs = append(msgs, string(res))
}
}
switch detect {
case "enter":
if fence.detect == nil || fence.detect["inside"] {
msgs = append(msgs, makemsg(details.command, group, "inside", hookName, metas, details.key, details.timestamp, res[1:]))
}
case "exit", "cross":
if fence.detect == nil || fence.detect["outside"] {
msgs = append(msgs, makemsg(details.command, group, "outside", hookName, metas, details.key, details.timestamp, res[1:]))
}
case "roam":
if len(msgs) > 0 {
var nmsgs []string
for i := range roamNearbys {
nmsg := extendRoamMessage(sw, fence,
"nearby", msgs[0], roamNearbys[i])
nmsgs = append(nmsgs, string(nmsg))
}
for i := range roamFaraways {
nmsg := extendRoamMessage(sw, fence,
"faraway", msgs[0], roamFaraways[i])
nmsgs = append(nmsgs, string(nmsg))
}
msgs = nmsgs
}
}
return msgs
}
func extendRoamMessage(
sw *scanWriter, fence *liveFenceSwitches,
kind string, baseMsg string, match roamMatch,
) string {
// hack off the last '}'
nmsg := []byte(baseMsg[:len(baseMsg)-1])
nmsg = append(nmsg, `,"`+kind+`":{"key":`...)
nmsg = appendJSONString(nmsg, fence.roam.key)
nmsg = append(nmsg, `,"id":`...)
nmsg = appendJSONString(nmsg, match.id)
nmsg = append(nmsg, `,"object":`...)
nmsg = match.obj.AppendJSON(nmsg)
nmsg = append(nmsg, `,"meters":`...)
nmsg = strconv.AppendFloat(nmsg,
math.Floor(match.meters*1000)/1000, 'f', -1, 64)
if fence.roam.scan != "" {
nmsg = append(nmsg, `,"scan":[`...)
col := sw.c.getCol(fence.roam.key)
if col != nil {
obj, _, ok := col.Get(match.id)
if ok {
nmsg = append(nmsg, `{"id":`...)
nmsg = appendJSONString(nmsg, match.id)
nmsg = append(nmsg, `,"self":true,"object":`...)
nmsg = obj.AppendJSON(nmsg)
nmsg = append(nmsg, '}')
}
pattern := match.id + fence.roam.scan
iterator := func(
oid string, o geojson.Object, fields *collection.Fields,
) bool {
if oid == match.id {
return true
}
if matched, _ := glob.Match(pattern, oid); matched {
nmsg = append(nmsg, `,{"id":`...)
nmsg = appendJSONString(nmsg, oid)
nmsg = append(nmsg, `,"object":`...)
nmsg = o.AppendJSON(nmsg)
nmsg = append(nmsg, '}')
}
return true
}
g := glob.Parse(pattern, false)
if g.Limits[0] == "" && g.Limits[1] == "" {
col.Scan(false, nil, iterator)
} else {
col.ScanRange(g.Limits[0], g.Limits[1],
false, nil, iterator)
}
}
nmsg = append(nmsg, ']')
}
nmsg = append(nmsg, '}')
// re-add the last '}'
nmsg = append(nmsg, '}')
return string(nmsg)
}
func makemsg(
command, group, detect, hookName string,
metas []FenceMeta, key string, t time.Time, tail string,
) string {
var buf []byte
buf = append(append(buf, `{"command":"`...), command...)
buf = append(append(buf, `","group":"`...), group...)
buf = append(append(buf, `","detect":"`...), detect...)
buf = append(buf, '"')
buf = appendHookDetails(buf, hookName, metas)
buf = appendJSONString(append(buf, `,"key":`...), key)
buf = appendJSONTimeFormat(append(buf, `,"time":`...), t)
buf = append(append(buf, ','), tail...)
return string(buf)
}
func fenceMatchObject(fence *liveFenceSwitches, obj geojson.Object) bool {
gobj, _ := obj.(geojson.Object)
if gobj == nil {
return false
}
if fence.roam.on {
// we need to check this object against
return false
}
switch fence.cmd {
case "nearby":
// nearby is an INTERSECT on a Circle
return gobj.Intersects(fence.obj)
case "within":
return gobj.Within(fence.obj)
case "intersects":
return gobj.Intersects(fence.obj)
}
return false
}
func fenceMatchRoam(
c *Server, fence *liveFenceSwitches,
tkey, tid string, obj geojson.Object,
) (nearbys, faraways []roamMatch) {
col := c.getCol(fence.roam.key)
if col == nil {
return
}
prevNearbys := fence.roam.nearbys[tid]
var newNearbys map[string]bool
center := obj.Center()
minLat, minLon, maxLat, maxLon :=
geo.RectFromCenter(center.Y, center.X, fence.roam.meters)
rect := geometry.Rect{
Min: geometry.Point{X: minLon, Y: minLat},
Max: geometry.Point{X: maxLon, Y: maxLat},
}
col.Intersects(geojson.NewRect(rect), 0, nil, func(
id string, obj2 geojson.Object, fields *collection.Fields,
) bool {
if c.hasExpired(fence.roam.key, id) {
return true
}
var idMatch bool
if id == tid {
return true // skip self
}
if fence.roam.pattern {
idMatch, _ = glob.Match(fence.roam.id, id)
} else {
idMatch = fence.roam.id == id
}
if !idMatch {
return true
}
if newNearbys == nil {
newNearbys = make(map[string]bool)
}
newNearbys[id] = true
prev := prevNearbys[id]
if prev {
delete(prevNearbys, id)
}
match := roamMatch{
id: id,
obj: obj2,
meters: obj.Distance(obj2),
}
if !prev || !fence.nodwell {
// brand new "nearby"
nearbys = append(nearbys, match)
}
return true
})
for id := range prevNearbys {
obj2, _, ok := col.Get(id)
if ok && !c.hasExpired(fence.roam.key, id) {
faraways = append(faraways, roamMatch{
id: id,
obj: obj2,
meters: obj.Distance(obj2),
})
}
}
if len(newNearbys) == 0 {
if fence.roam.nearbys != nil {
delete(fence.roam.nearbys, tid)
if len(fence.roam.nearbys) == 0 {
fence.roam.nearbys = nil
}
}
} else {
if fence.roam.nearbys == nil {
fence.roam.nearbys = make(map[string]map[string]bool)
}
fence.roam.nearbys[tid] = newNearbys
}
return
}