processorLineString

Author: amyasnikov

geojson.go

@@ -3,6 +3,7 @@ package srtm
 import (
 	geojson "github.com/paulmach/go.geojson"
 	"github.com/rs/zerolog/log"
+	"sync"
 )
 
 // AddElevation returns point with 3 coordinates: [longitude, latitude, elevation]
@@ -26,11 +27,26 @@ func AddElevation(point []float64) ([]float64, error) {
 	return append(point[:2], float64(elevation)), nil
 }
 
+func processorLineString(wg *sync.WaitGroup, geoJson *geojson.Geometry, i int, skipErrors bool) {
+	point, err := AddElevation(geoJson.LineString[i])
+	if err != nil && !skipErrors {
+		log.Error().Caller().Err(err).Msg("")
+	}
+	geoJson.LineString[i] = point
+	if wg != nil {
+		wg.Done()
+	}
+}
+
 // AddElevations returns geojson with added third coordinate (elevation)
 // Param tileDir - directory of hgt-tiles
 // Param geoJson - geojson for processing
 // Param skipErrors - if false AddElevations use premature exit (on first bad point in geojson). if true all points will be process but bad point will not to be contains elevation coordinate
 func AddElevations(geoJson *geojson.Geometry, skipErrors bool) (*geojson.Geometry, error) {
+	var wg *sync.WaitGroup
+	if parallel {
+		wg = &sync.WaitGroup{}
+	}
 	switch geoJson.Type {
 	case geojson.GeometryPoint:
 		point, err := AddElevation(geoJson.Point)
@@ -40,14 +56,16 @@ func AddElevations(geoJson *geojson.Geometry, skipErrors bool) (*geojson.Geometr
 		geoJson.Point = point
 		return geoJson, nil
 	case geojson.GeometryLineString:
+		if parallel {
+			wg.Add(len(geoJson.LineString))
+		}
 		for i := range geoJson.LineString {
-			point, err := AddElevation(geoJson.LineString[i])
-			if err != nil && !skipErrors {
-				log.Error().Caller().Err(err).Msg("")
+			if parallel {
+				go processorLineString(wg, geoJson, i, skipErrors)
+			} else {
+				processorLineString(nil, geoJson, i, skipErrors)
 			}
-			geoJson.LineString[i] = point
 		}
-		return geoJson, nil
 	case geojson.GeometryMultiPoint:
 		for i := range geoJson.MultiPoint {
 			point, err := AddElevation(geoJson.MultiPoint[i])
@@ -56,7 +74,6 @@ func AddElevations(geoJson *geojson.Geometry, skipErrors bool) (*geojson.Geometr
 			}
 			geoJson.MultiPoint[i] = point
 		}
-		return geoJson, nil
 	case geojson.GeometryPolygon:
 		for i := range geoJson.Polygon {
 			for j := range geoJson.Polygon[i] {
@@ -67,7 +84,6 @@ func AddElevations(geoJson *geojson.Geometry, skipErrors bool) (*geojson.Geometr
 				geoJson.Polygon[i][j] = point
 			}
 		}
-		return geoJson, nil
 	case geojson.GeometryMultiLineString:
 		for i := range geoJson.MultiLineString {
 			for j := range geoJson.MultiLineString[i] {
@@ -78,8 +94,9 @@ func AddElevations(geoJson *geojson.Geometry, skipErrors bool) (*geojson.Geometr
 				geoJson.MultiLineString[i][j] = point
 			}
 		}
-		return geoJson, nil
-	default:
-		return geoJson, nil
 	}
+	if parallel {
+		wg.Wait()
+	}
+	return geoJson, nil
 }