Improve issue search (#2387)

* Improve issue indexer

* Fix new issue sqlite bug

* Different test indexer paths for each db

* Add integration indexer paths to make clean

vendor/github.com/blevesearch/bleve/geo/geo.go

@@ -0,0 +1,170 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package geo
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/blevesearch/bleve/numeric"
+)
+
+// GeoBits is the number of bits used for a single geo point
+// Currently this is 32bits for lon and 32bits for lat
+var GeoBits uint = 32
+
+var minLon = -180.0
+var minLat = -90.0
+var maxLon = 180.0
+var maxLat = 90.0
+var minLonRad = minLon * degreesToRadian
+var minLatRad = minLat * degreesToRadian
+var maxLonRad = maxLon * degreesToRadian
+var maxLatRad = maxLat * degreesToRadian
+var geoTolerance = 1E-6
+var lonScale = float64((uint64(0x1)<<GeoBits)-1) / 360.0
+var latScale = float64((uint64(0x1)<<GeoBits)-1) / 180.0
+
+// MortonHash computes the morton hash value for the provided geo point
+// This point is ordered as lon, lat.
+func MortonHash(lon, lat float64) uint64 {
+	return numeric.Interleave(scaleLon(lon), scaleLat(lat))
+}
+
+func scaleLon(lon float64) uint64 {
+	rv := uint64((lon - minLon) * lonScale)
+	return rv
+}
+
+func scaleLat(lat float64) uint64 {
+	rv := uint64((lat - minLat) * latScale)
+	return rv
+}
+
+// MortonUnhashLon extracts the longitude value from the provided morton hash.
+func MortonUnhashLon(hash uint64) float64 {
+	return unscaleLon(numeric.Deinterleave(hash))
+}
+
+// MortonUnhashLat extracts the latitude value from the provided morton hash.
+func MortonUnhashLat(hash uint64) float64 {
+	return unscaleLat(numeric.Deinterleave(hash >> 1))
+}
+
+func unscaleLon(lon uint64) float64 {
+	return (float64(lon) / lonScale) + minLon
+}
+
+func unscaleLat(lat uint64) float64 {
+	return (float64(lat) / latScale) + minLat
+}
+
+// compareGeo will compare two float values and see if they are the same
+// taking into consideration a known geo tolerance.
+func compareGeo(a, b float64) float64 {
+	compare := a - b
+	if math.Abs(compare) <= geoTolerance {
+		return 0
+	}
+	return compare
+}
+
+// RectIntersects checks whether rectangles a and b intersect
+func RectIntersects(aMinX, aMinY, aMaxX, aMaxY, bMinX, bMinY, bMaxX, bMaxY float64) bool {
+	return !(aMaxX < bMinX || aMinX > bMaxX || aMaxY < bMinY || aMinY > bMaxY)
+}
+
+// RectWithin checks whether box a is within box b
+func RectWithin(aMinX, aMinY, aMaxX, aMaxY, bMinX, bMinY, bMaxX, bMaxY float64) bool {
+	rv := !(aMinX < bMinX || aMinY < bMinY || aMaxX > bMaxX || aMaxY > bMaxY)
+	return rv
+}
+
+// BoundingBoxContains checks whether the lon/lat point is within the box
+func BoundingBoxContains(lon, lat, minLon, minLat, maxLon, maxLat float64) bool {
+	return compareGeo(lon, minLon) >= 0 && compareGeo(lon, maxLon) <= 0 &&
+		compareGeo(lat, minLat) >= 0 && compareGeo(lat, maxLat) <= 0
+}
+
+const degreesToRadian = math.Pi / 180
+const radiansToDegrees = 180 / math.Pi
+
+// DegreesToRadians converts an angle in degrees to radians
+func DegreesToRadians(d float64) float64 {
+	return d * degreesToRadian
+}
+
+// RadiansToDegrees converts an angle in radians to degress
+func RadiansToDegrees(r float64) float64 {
+	return r * radiansToDegrees
+}
+
+var earthMeanRadiusMeters = 6371008.7714
+
+func RectFromPointDistance(lon, lat, dist float64) (float64, float64, float64, float64, error) {
+	err := checkLongitude(lon)
+	if err != nil {
+		return 0, 0, 0, 0, err
+	}
+	err = checkLatitude(lat)
+	if err != nil {
+		return 0, 0, 0, 0, err
+	}
+	radLon := DegreesToRadians(lon)
+	radLat := DegreesToRadians(lat)
+	radDistance := (dist + 7e-2) / earthMeanRadiusMeters
+
+	minLatL := radLat - radDistance
+	maxLatL := radLat + radDistance
+
+	var minLonL, maxLonL float64
+	if minLatL > minLatRad && maxLatL < maxLatRad {
+		deltaLon := asin(sin(radDistance) / cos(radLat))
+		minLonL = radLon - deltaLon
+		if minLonL < minLonRad {
+			minLonL += 2 * math.Pi
+		}
+		maxLonL = radLon + deltaLon
+		if maxLonL > maxLonRad {
+			maxLonL -= 2 * math.Pi
+		}
+	} else {
+		// pole is inside distance
+		minLatL = math.Max(minLatL, minLatRad)
+		maxLatL = math.Min(maxLatL, maxLatRad)
+		minLonL = minLonRad
+		maxLonL = maxLonRad
+	}
+
+	return RadiansToDegrees(minLonL),
+		RadiansToDegrees(maxLatL),
+		RadiansToDegrees(maxLonL),
+		RadiansToDegrees(minLatL),
+		nil
+}
+
+func checkLatitude(latitude float64) error {
+	if math.IsNaN(latitude) || latitude < minLat || latitude > maxLat {
+		return fmt.Errorf("invalid latitude %f; must be between %f and %f", latitude, minLat, maxLat)
+	}
+	return nil
+}
+
+func checkLongitude(longitude float64) error {
+	if math.IsNaN(longitude) || longitude < minLon || longitude > maxLon {
+		return fmt.Errorf("invalid longitude %f; must be between %f and %f", longitude, minLon, maxLon)
+	}
+	return nil
+}