Fix sporadic kNN results when TTL is used

fixes #326

pkg/controller/search.go

@@ -87,6 +87,7 @@ func (c *Controller) cmdSearchArgs(cmd string, vs []resp.Value, types []string)
 		err = errInvalidArgument(typ)
 		return
 	}
+	s.meters = -1 // this will become non-negative if search is within a circle
 	switch ltyp {
 	case "point":
 		var slat, slon, smeters string
@@ -127,6 +128,41 @@ func (c *Controller) cmdSearchArgs(cmd string, vs []resp.Value, types []string)
 				err = errInvalidArgument(smeters)
 				return
 			}
+			if s.meters < 0 {
+				err = errInvalidArgument(smeters)
+				return
+			}
+		}
+	case "circle":
+		var slat, slon, smeters string
+		if vs, slat, ok = tokenval(vs); !ok || slat == "" {
+			err = errInvalidNumberOfArguments
+			return
+		}
+		if vs, slon, ok = tokenval(vs); !ok || slon == "" {
+			err = errInvalidNumberOfArguments
+			return
+		}
+		if vs, smeters, ok = tokenval(vs); !ok || smeters == "" {
+			err = errInvalidArgument(slat)
+			return
+		}
+
+		if s.lat, err = strconv.ParseFloat(slat, 64); err != nil {
+			err = errInvalidArgument(slat)
+			return
+		}
+		if s.lon, err = strconv.ParseFloat(slon, 64); err != nil {
+			err = errInvalidArgument(slon)
+			return
+		}
+		if s.meters, err = strconv.ParseFloat(smeters, 64); err != nil {
+			err = errInvalidArgument(smeters)
+			return
+		}
+		if s.meters < 0 {
+			err = errInvalidArgument(smeters)
+			return
 		}
 	case "object":
 		var obj string
@@ -292,7 +328,8 @@ func (c *Controller) cmdSearchArgs(cmd string, vs []resp.Value, types []string)
 }
 
 var nearbyTypes = []string{"point"}
-var withinOrIntersectsTypes = []string{"geo", "bounds", "hash", "tile", "quadkey", "get", "object"}
+var withinOrIntersectsTypes = []string{
+	"geo", "bounds", "hash", "tile", "quadkey", "get", "object", "circle"}
 
 func (c *Controller) cmdNearby(msg *server.Message) (res resp.Value, err error) {
 	start := time.Now()
@@ -376,32 +413,28 @@ type iterItem struct {
 	dist   float64
 }
 
-func (c *Controller) nearestNeighbors(
-	s *liveFenceSwitches, sw *scanWriter, lat, lon float64, matched *uint32,
-	iter func(id string, o geojson.Object, fields []float64, dist *float64) bool,
-) {
+func (c *Controller) nearestNeighbors(s *liveFenceSwitches, sw *scanWriter, lat, lon float64, matched *uint32,
+	iter func(id string, o geojson.Object, fields []float64, dist *float64) bool) {
 	limit := int(sw.cursor + sw.limit)
 	var items []iterItem
-	sw.col.NearestNeighbors(lat, lon,
-		func(id string, o geojson.Object, fields []float64) bool {
-			if c.hasExpired(s.key, id) {
-				return true
-			}
-			if _, ok := sw.fieldMatch(fields, o); !ok {
-				return true
-			}
-			match, keepGoing := sw.globMatch(id, o)
-			if !match {
-				return true
-			}
-			dist := o.CalculatedPoint().DistanceTo(geojson.Position{X: lon, Y: lat, Z: 0})
-			items = append(items, iterItem{id: id, o: o, fields: fields, dist: dist})
-			if !keepGoing {
-				return false
-			}
-			return len(items) < limit
-		},
-	)
+	sw.col.NearestNeighbors(lat, lon, func(id string, o geojson.Object, fields []float64) bool {
+		if c.hasExpired(s.key, id) {
+			return true
+		}
+		if _, ok := sw.fieldMatch(fields, o); !ok {
+			return true
+		}
+		match, keepGoing := sw.globMatch(id, o)
+		if !match {
+			return true
+		}
+		dist := o.CalculatedPoint().DistanceTo(geojson.Position{X: lon, Y: lat, Z: 0})
+		items = append(items, iterItem{id: id, o: o, fields: fields, dist: dist})
+		if !keepGoing {
+			return false
+		}
+		return len(items) < limit
+	})
 	sort.Slice(items, func(i, j int) bool {
 		return items[i].dist < items[j].dist
 	})
@@ -456,7 +489,11 @@ func (c *Controller) cmdWithinOrIntersects(cmd string, msg *server.Message) (res
 	if sw.col != nil {
 		minZ, maxZ := zMinMaxFromWheres(s.wheres)
 		if cmd == "within" {
-			sw.col.Within(s.sparse, s.o, s.minLat, s.minLon, s.maxLat, s.maxLon, minZ, maxZ,
+			sw.col.Within(s.sparse,
+				s.o,
+				s.minLat, s.minLon, s.maxLat, s.maxLon,
+				s.lat, s.lon, s.meters,
+				minZ, maxZ,
 				func(id string, o geojson.Object, fields []float64) bool {
 					if c.hasExpired(s.key, id) {
 						return true
@@ -470,7 +507,11 @@ func (c *Controller) cmdWithinOrIntersects(cmd string, msg *server.Message) (res
 				},
 			)
 		} else if cmd == "intersects" {
-			sw.col.Intersects(s.sparse, s.o, s.minLat, s.minLon, s.maxLat, s.maxLon, minZ, maxZ,
+			sw.col.Intersects(s.sparse,
+				s.o,
+				s.minLat, s.minLon, s.maxLat, s.maxLon,
+				s.lat, s.lon, s.meters,
+				minZ, maxZ,
 				func(id string, o geojson.Object, fields []float64) bool {
 					if c.hasExpired(s.key, id) {
 						return true