refactor: Refactor station finder to support via Telenav search and v…

…ia local search (#271)

issue: #270

integration/cmd/oasis/flags.go

@@ -7,6 +7,7 @@ import (
 var flags struct {
 	listenPort           int
 	osrmBackendEndpoint  string
+	finderType           string
 	tnSearchEndpoint     string
 	tnSearchAPIKey       string
 	tnSearchAPISignature string
@@ -15,6 +16,7 @@ var flags struct {
 func init() {
 	flag.IntVar(&flags.listenPort, "p", 8090, "Listen port.")
 	flag.StringVar(&flags.osrmBackendEndpoint, "osrm", "", "OSRM-backend endpoint")
+	flag.StringVar(&flags.finderType, "finder", "", "Specify search finder to search for nearby charge stations for given location, use TNSearchFinder or LocalIndexerFinder")
 	flag.StringVar(&flags.tnSearchEndpoint, "search", "", "TN-Search-backend endpoint")
 	flag.StringVar(&flags.tnSearchAPIKey, "searchApiKey", "", "API key for TN-Search-backend")
 	flag.StringVar(&flags.tnSearchAPISignature, "searchApiSignature", "", "API Signature for  TN-Search-backend")

integration/cmd/oasis/main.go

@@ -14,7 +14,12 @@ func main() {
 	defer glog.Flush()
 	mux := http.NewServeMux()
 
-	oasisService := oasis.New(flags.osrmBackendEndpoint, flags.tnSearchEndpoint, flags.tnSearchAPIKey, flags.tnSearchAPISignature)
+	oasisService, err := oasis.New(flags.osrmBackendEndpoint, flags.finderType, flags.tnSearchEndpoint, flags.tnSearchAPIKey, flags.tnSearchAPISignature)
+	if err != nil {
+		glog.Errorf("Failed to create oasis handler due to err %+v.\n", err)
+		return
+	}
+
 	mux.Handle("/oasis/v1/earliest/", oasisService)
 
 	// listen

integration/service/oasis/handler.go

@@ -8,23 +8,35 @@ import (
 	"github.com/Telenav/osrm-backend/integration/pkg/api/oasis"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/osrmconnector"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/osrmhelper"
-	"github.com/Telenav/osrm-backend/integration/service/oasis/searchconnector"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder"
 	"github.com/golang/glog"
 )
 
 // Handler handles oasis request and provide response
 type Handler struct {
-	osrmConnector     *osrmconnector.OSRMConnector
-	tnSearchConnector *searchconnector.TNSearchConnector
+	osrmConnector *osrmconnector.OSRMConnector
+	finder        stationfinder.StationFinder
 }
 
 // New creates new Handler object
-func New(osrmBackend, searchEndpoint, apiKey, apiSignature string) *Handler {
+func New(osrmBackend, finderType, searchEndpoint, apiKey, apiSignature string) (*Handler, error) {
 	// @todo: need make sure connectivity is on and continues available
-	return &Handler{
-		osrmConnector:     osrmconnector.NewOSRMConnector(osrmBackend),
-		tnSearchConnector: searchconnector.NewTNSearchConnector(searchEndpoint, apiKey, apiSignature),
+	//        simple request to guarantee server is alive after init
+	if len(osrmBackend) == 0 {
+		err := fmt.Errorf("empty osrmBackend end point")
+		return nil, err
+	}
+
+	finder, err := stationfinder.CreateStationsFinder(finderType, searchEndpoint, apiKey, apiSignature)
+	if err != nil {
+		glog.Errorf("Failed in Handler's New() when try to call CreateStationsFinder(), met error = %+v\n", err)
+		return nil, err
 	}
+
+	return &Handler{
+		osrmConnector: osrmconnector.NewOSRMConnector(osrmBackend),
+		finder:        finder,
+	}, nil
 }
 
 func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
@@ -71,14 +83,14 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 
 	// check whether could achieve by single charge
-	overlap := getOverlapChargeStations4OrigDest(oasisReq, routeResp.Routes[0].Distance, h.osrmConnector, h.tnSearchConnector)
+	overlap := getOverlapChargeStations4OrigDest(oasisReq, routeResp.Routes[0].Distance, h.osrmConnector, h.finder)
 	if len(overlap) > 0 {
 		generateResponse4SingleChargeStation(w, oasisReq, overlap, h.osrmConnector)
 		return
 	}
 
 	// generate result for multiple charge
-	generateSolutions4MultipleCharge(w, oasisReq, routeResp, h.osrmConnector, h.tnSearchConnector)
+	generateSolutions4MultipleCharge(w, oasisReq, routeResp, h.osrmConnector, h.finder)
 	return
 }
 

integration/service/oasis/reachable_by_multiple_charge.go

@@ -10,17 +10,17 @@ import (
 	"github.com/Telenav/osrm-backend/integration/service/oasis/chargingstrategy"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/haversine"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/osrmconnector"
-	"github.com/Telenav/osrm-backend/integration/service/oasis/searchconnector"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder/stationfinderalg"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/stationgraph"
 	"github.com/golang/glog"
 
 	"github.com/twpayne/go-polyline"
 )
 
 // @todo: handle negative situation
-func generateSolutions4MultipleCharge(w http.ResponseWriter, oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, sc *searchconnector.TNSearchConnector) {
-	solutions := generateSolutionsWithEarlistArrival(oasisReq, routeResp, oc, sc)
+func generateSolutions4MultipleCharge(w http.ResponseWriter, oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, finder stationfinder.StationFinder) {
+	solutions := generateSolutionsWithEarlistArrival(oasisReq, routeResp, oc, finder)
 
 	w.WriteHeader(http.StatusOK)
 	r := new(oasis.Response)
@@ -32,12 +32,12 @@ func generateSolutions4MultipleCharge(w http.ResponseWriter, oasisReq *oasis.Req
 	json.NewEncoder(w).Encode(r)
 }
 
-func generateSolutionsWithEarlistArrival(oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, sc *searchconnector.TNSearchConnector) []*oasis.Solution {
+func generateSolutionsWithEarlistArrival(oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, finder stationfinder.StationFinder) []*oasis.Solution {
 	targetSolutions := make([]*oasis.Solution, 0)
 
 	chargeLocations := chargeLocationSelection(oasisReq, routeResp)
 	for _, locations := range chargeLocations {
-		c := stationfinder.CalculateWeightBetweenNeighbors(locations, oc, sc)
+		c := stationfinderalg.CalculateWeightBetweenNeighbors(locations, oc, finder)
 		internalSolutions := stationgraph.NewStationGraph(c, oasisReq.CurrRange, oasisReq.MaxRange,
 			chargingstrategy.NewFakeChargingStrategy(oasisReq.MaxRange)).GenerateChargeSolutions()
 

integration/service/oasis/reachable_by_single_charge.go

@@ -12,8 +12,8 @@ import (
 	"github.com/Telenav/osrm-backend/integration/pkg/api/search/nearbychargestation"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/osrmconnector"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/osrmhelper"
-	"github.com/Telenav/osrm-backend/integration/service/oasis/searchconnector"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder/stationfinderalg"
 	"github.com/golang/glog"
 )
 
@@ -25,15 +25,15 @@ const maxOverlapPointsNum = 500
 // The energy level is safeRange + nearest charge station's distance to destination
 // If there is one or several charge stations could be found in both origStationsResp and destStationsResp
 // We think the result is reachable by single charge station
-func getOverlapChargeStations4OrigDest(req *oasis.Request, routedistance float64, osrmConnector *osrmconnector.OSRMConnector, tnSearchConnector *searchconnector.TNSearchConnector) coordinate.Coordinates {
+func getOverlapChargeStations4OrigDest(req *oasis.Request, routedistance float64, osrmConnector *osrmconnector.OSRMConnector, finder stationfinder.StationFinder) coordinate.Coordinates {
 	// only possible when currRange + maxRange > distance + safeRange
 	if req.CurrRange+req.MaxRange < routedistance+req.SafeLevel {
 		return nil
 	}
 
-	origStations := stationfinder.NewOrigStationFinder(tnSearchConnector, req)
-	destStations := stationfinder.NewDestStationFinder(tnSearchConnector, req)
-	overlap := stationfinder.FindOverlapBetweenStations(origStations, destStations)
+	origStations := finder.NewOrigStationFinder(req)
+	destStations := finder.NewDestStationFinder(req)
+	overlap := stationfinderalg.FindOverlapBetweenStations(origStations, destStations)
 
 	if len(overlap) == 0 {
 		return nil

integration/service/oasis/stationfinder/doc.go

@@ -1,21 +1,36 @@
-// Package stationfinder provide functionality to find nearby charge stations and
-// related algorithm.
-// Finders:
-// - origStationFinder holds logic for how to find reachable charge stations
-//   based on current energy level.
-// - destStationFinder holds logic for how to find reachable charge stations
-//   based on safe energy level and distance to nearest charge station(todo).
-// - lowEnergyLocationStationFinder holds logic for how to find reachable
-//   charge station near certain location.
-// - orig_iterator and dest_iterator wraps single point of orig/dest which could
-//   be used for algorithms
+/*
 
-// Algorithm:
-// - Each finder provide iterator to iterate charge station candidates.
-// - The choice of channel as response makes algorithm could be asynchronous func.
-// - FindOverlapBetweenStations provide functionality to find overlap
-//   between two iterator.
-// - CalcWeightBetweenChargeStationsPair provide functionality to calculate
-//   cost between two group of charge stations which could construct a new
-//   graph as edges.
+Package stationfinder provide functionality to find nearby charge stations and
+related algorithm.
+It's find functionality could be achieved by:
+- TNSearchFinder, which is implemented by Telenav's search web service.
+  + The data source is from professional data
+  + Based on Lucence and hilbert value
+  + Could potentially supports dynamic information
+
+- LocalIndexerFinder
+  + Support any kind of data sources as long as following format defined in https://github.com/Telenav/osrm-backend/issues/237#issue-585201041
+  + For Telenav usage, uses the same source with Telenav search service
+  + Spatial index is build based on google s2
+
+Finders:
+- origStationFinder holds logic for how to find reachable charge stations
+  based on current energy level.
+- destStationFinder holds logic for how to find reachable charge stations
+  based on safe energy level and distance to nearest charge station(todo).
+- lowEnergyLocationStationFinder holds logic for how to find reachable
+  charge station near certain location.
+- orig_iterator and dest_iterator wraps single point of orig/dest which could
+  be used for algorithms
+
+Algorithm:
+- Each finder provide iterator to iterate charge station candidates.
+- The choice of channel as response makes algorithm could be asynchronous func.
+- FindOverlapBetweenStations provide functionality to find overlap
+  between two iterator.
+- CalcWeightBetweenChargeStationsPair provide functionality to calculate
+  cost between two group of charge stations which could construct a new
+  graph as edges.
+
+*/
 package stationfinder

integration/service/oasis/stationfinder/interface.go

@@ -0,0 +1,39 @@
+package stationfinder
+
+import (
+	"github.com/Telenav/osrm-backend/integration/pkg/api/nav"
+	"github.com/Telenav/osrm-backend/integration/pkg/api/oasis"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/osrmconnector"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder/stationfindertype"
+)
+
+// StationFinder creates finders for different purpose, all finders must implement NearbyStationsIterator interface
+type StationFinder interface {
+	// NewOrigStationFinder creates finder to search for nearby charge stations near orig
+	NewOrigStationFinder(oasisReq *oasis.Request) stationfindertype.NearbyStationsIterator
+
+	// NewDestStationFinder creates finder to search for nearby charge stations near destination
+	NewDestStationFinder(oasisReq *oasis.Request) stationfindertype.NearbyStationsIterator
+
+	// NewLowEnergyLocationStationFinder creates finder to search for nearby charge stations when energy is low
+	NewLowEnergyLocationStationFinder(location *nav.Location) stationfindertype.NearbyStationsIterator
+}
+
+// Algorithm contains algorithm implemented based on NearbyStationsIterator
+type Algorithm interface {
+	// FindOverlapBetweenStations finds overlap charge stations based on two iterator
+	FindOverlapBetweenStations(iterF stationfindertype.NearbyStationsIterator,
+		iterS stationfindertype.NearbyStationsIterator) []stationfindertype.ChargeStationInfo
+
+	// CalcWeightBetweenChargeStationsPair accepts two iterators and calculates weights between each pair of iterators
+	CalcWeightBetweenChargeStationsPair(from stationfindertype.NearbyStationsIterator,
+		to stationfindertype.NearbyStationsIterator,
+		table osrmconnector.TableRequster) ([]stationfindertype.NeighborInfo, error)
+
+	// CalculateWeightBetweenNeighbors accepts locations array, which will search for nearby
+	// charge stations and then calculate weight between stations, the result is used to
+	// construct graph.
+	CalculateWeightBetweenNeighbors(locations []*nav.Location,
+		oc *osrmconnector.OSRMConnector,
+		finder StationFinder) chan stationfindertype.WeightBetweenNeighbors
+}