feat: integrate pre-generated connectivity data with OASIS service (#339

)

* feat: integrate station connectivity finder with service
issue: #242

* fix: add filter in node_graph to avoid visiting unreachable stations
issue: #338

CHANGELOG-FORK.md

@@ -25,12 +25,14 @@ Changes from v10.2.0
   - CHANGED for internal refactoring, rename `cmd/osrm-ranking` to `cmd/osrm-rankd` [#317](https://github.com/Telenav/osrm-backend/pull/317)
   - ADDED versioning on golang binaries [#320](https://github.com/Telenav/osrm-backend/pull/320)
   - ADDED package `util/appversion` to share versioning among many golang binaries [#328](https://github.com/Telenav/osrm-backend/pull/328)
-  - ADDED package `stationconnquerier` which builds station connectivity graph based on pre-build data [#323](https://github.com/Telenav/osrm-backend/pull/323)
+  - ADDED package `oasis/stationconnquerier` which builds station connectivity graph based on pre-build data [#323](https://github.com/Telenav/osrm-backend/pull/323)
   - ADDED `Duration` for pre-generated charge station connectivity data [#326](https://github.com/Telenav/osrm-backend/issues/326)
   - CHANGED for internal refactoring, use `osrm.xxx` to invoke OSRM APIs, e.g. `osrm.Coordinate` instead of `coordinate.Coordinate` [#327](https://github.com/Telenav/osrm-backend/pull/327)
   - CHANGED for epsilon of util/floatequals, use different epsilon for float32 compare and float64 compare [#332](https://github.com/Telenav/osrm-backend/issues/332)
   - ADDED interface test for `trafficapplyingmodel` implementation(both `appendspeedonly` and `preferlivetraffic`) [#330](https://github.com/Telenav/osrm-backend/pull/330) 
   - CHANGED for mock objects, hide them in internal/mock package for OASIS service [#334](https://github.com/Telenav/osrm-backend/issues/334)
+  - ADDED package `oasis/selectionstrategy`, move logic related with how to select optimum charge stations into this package [#339](https://github.com/Telenav/osrm-backend/pull/339)
+  - CHANGED for integration of pre-generated connectivity data with OASIS service [#339](https://github.com/Telenav/osrm-backend/pull/339)
 
 - Bugfix:    
   - CHANGED `osrm-ranking` parsing of OSRM route response to compatible with `string` array `annotation/nodes` [#296](https://github.com/Telenav/osrm-backend/pull/296)     

integration/cmd/place-connectivity-gen/main.go

@@ -37,7 +37,7 @@ func main() {
 	}
 	indexer.Dump(flags.outputFolder)
 
-	connectivitymap.NewConnectivityMap(flags.maxRange).
+	connectivitymap.New(flags.maxRange).
 		Build(indexer, indexer, rankerStrategy, flags.numberOfWorkers).
 		Dump(flags.outputFolder)
 

integration/service/oasis/connectivitymap/builder.go

@@ -84,6 +84,11 @@ func (builder *connectivityMapBuilder) work(workerID int, source <-chan spatiali
 
 		ids := make([]IDAndWeight, 0, len(rankedResults))
 		for _, r := range rankedResults {
+			// skip connectivity to itself
+			if r.ID == p.ID {
+				continue
+			}
+
 			ids = append(ids, IDAndWeight{
 				ID: r.ID,
 				Weight: Weight{

integration/service/oasis/connectivitymap/connectivity_map.go

@@ -27,8 +27,8 @@ type ConnectivityMap struct {
 	statistic    *statistic
 }
 
-// NewConnectivityMap creates ConnectivityMap
-func NewConnectivityMap(maxRange float64) *ConnectivityMap {
+// New creates ConnectivityMap
+func New(maxRange float64) *ConnectivityMap {
 	return &ConnectivityMap{
 		maxRange:  maxRange,
 		statistic: newStatistic(),

integration/service/oasis/connectivitymap/dumper_test.go

@@ -36,7 +36,7 @@ func TestDumpGivenObjectThenLoadAndThenCompareWithOriginalObject(t *testing.T) {
 			t.Errorf("During running serializeConnectivityMap for case %v, met error %v", c, err)
 		}
 
-		actual := NewConnectivityMap(0.0)
+		actual := New(0.0)
 		if err := deSerializeConnectivityMap(actual, path); err != nil {
 			t.Errorf("During running deSerializeConnectivityMap for case %v, met error %v", c, err)
 		}

integration/service/oasis/handler.go

@@ -6,36 +6,26 @@ import (
 	"net/http"
 
 	"github.com/Telenav/osrm-backend/integration/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/stationfinder"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/selectionstrategy"
 	"github.com/golang/glog"
 )
 
 // Handler handles oasis request and provide response
 type Handler struct {
-	osrmConnector *osrmconnector.OSRMConnector
-	finder        stationfinder.StationFinder
+	resourceMgr *selectionstrategy.ResourceMgr
 }
 
 // New creates new Handler object
 func New(osrmBackend, finderType, searchEndpoint, apiKey, apiSignature, dataFolderPath string) (*Handler, error) {
-	// @todo: need make sure connectivity is on and continues available
-	//        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, dataFolderPath)
+	resourceMgr, err := selectionstrategy.NewResourceMgr(osrmBackend, finderType, searchEndpoint, apiKey, apiSignature, dataFolderPath)
 	if err != nil {
-		glog.Errorf("Failed in Handler's New() when try to call CreateStationsFinder(), met error = %+v\n", err)
+		glog.Errorf("Failed to create Handler due to error %+v.\n", err)
 		return nil, err
 	}
 
 	return &Handler{
-		osrmConnector: osrmconnector.NewOSRMConnector(osrmBackend),
-		finder:        finder,
+		resourceMgr: resourceMgr,
 	}, nil
 }
 
@@ -52,7 +42,7 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 
 	// generate route response based on given oasis's orig/destination
-	routeResp, err := osrmhelper.RequestRoute4InputOrigDest(oasisReq, h.osrmConnector)
+	routeResp, err := osrmhelper.RequestRoute4InputOrigDest(oasisReq, h.resourceMgr.OSRMConnector())
 	if err != nil {
 		glog.Error(err)
 		w.WriteHeader(http.StatusOK)
@@ -70,27 +60,27 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 
 	// check whether has enough energy
-	b, remainRange, err := hasEnoughEnergy(oasisReq.CurrRange, oasisReq.SafeLevel, routeResp)
+	b, remainRange, err := selectionstrategy.HasEnoughEnergy(oasisReq.CurrRange, oasisReq.SafeLevel, routeResp)
 	if err != nil {
 		glog.Error(err)
 		w.WriteHeader(http.StatusOK)
 		fmt.Fprintf(w, "%v", err)
 		return
 	}
 	if b {
-		generateOASISResponse4NoChargeNeeded(w, routeResp, remainRange)
+		selectionstrategy.GenerateOASISResponse4NoChargeNeeded(w, routeResp, remainRange)
 		return
 	}
 
 	// check whether could achieve by single charge
-	overlap := getOverlapChargeStations4OrigDest(oasisReq, routeResp.Routes[0].Distance, h.osrmConnector, h.finder)
+	overlap := selectionstrategy.GetOverlapChargeStations4OrigDest(oasisReq, routeResp.Routes[0].Distance, h.resourceMgr)
 	if len(overlap) > 0 {
-		generateResponse4SingleChargeStation(w, oasisReq, overlap, h.osrmConnector)
+		selectionstrategy.GenerateResponse4SingleChargeStation(w, oasisReq, overlap, h.resourceMgr)
 		return
 	}
 
 	// generate result for multiple charge
-	generateSolutions4MultipleCharge(w, oasisReq, routeResp, h.osrmConnector, h.finder)
+	selectionstrategy.GenerateSolutions4MultipleCharge(w, oasisReq, routeResp, h.resourceMgr)
 	return
 }
 

integration/service/oasis/selectionstrategy/doc.go

@@ -0,0 +1,11 @@
+/*
+Package selectionstrategy contains logic related with charge station selection related logic.
+It contains logic of:
+- detect wether destination is reachable or not
+- detect whether charge is needed or not
+- if charge for one time could reach destination, find best solution
+- best solution for multiple charge
+   + SearchAlongRoute(comment temporarily)
+   + ChargeStationBasedStrategy
+*/
+package selectionstrategy

integration/service/oasis/has_enough_energy.go → integration/service/oasis/selectionstrategy/has_enough_energy.go

@@ -1,4 +1,4 @@
-package oasis
+package selectionstrategy
 
 import (
 	"encoding/json"
@@ -13,7 +13,7 @@ import (
 // currRange: current energy level, represent by distance(unit: meters)
 // destRange: energy level required to destination
 // currRange - routeDistance > destRange means no charge station is needed
-func hasEnoughEnergy(currRange, destRange float64, routeResp *route.Response) (bool, float64, error) {
+func HasEnoughEnergy(currRange, destRange float64, routeResp *route.Response) (bool, float64, error) {
 	if len(routeResp.Routes) == 0 {
 		err := fmt.Errorf("route response contains no route result")
 		return false, 0, err
@@ -42,7 +42,8 @@ func hasEnoughEnergy(currRange, destRange float64, routeResp *route.Response) (b
 	return false, remainRange, nil
 }
 
-func generateOASISResponse4NoChargeNeeded(w http.ResponseWriter, routeResp *route.Response, remainRange float64) {
+// GenerateOASISResponse4NoChargeNeeded generates response for no charge needed
+func GenerateOASISResponse4NoChargeNeeded(w http.ResponseWriter, routeResp *route.Response, remainRange float64) {
 	w.WriteHeader(http.StatusOK)
 
 	solution := new(oasis.Solution)

integration/service/oasis/has_enough_energy_test.go → integration/service/oasis/selectionstrategy/has_enough_energy_test.go

@@ -1,4 +1,4 @@
-package oasis
+package selectionstrategy
 
 import (
 	"strconv"
@@ -10,12 +10,12 @@ import (
 
 func TestHasEnoughEnergyPositive1(t *testing.T) {
 	response := &route.Response{
-		Routes: []*route.Route{&route.Route{Distance: 10000.0}},
+		Routes: []*route.Route{{Distance: 10000.0}},
 	}
 
 	currRange := 20000.0
 	destRange := 5000.0
-	b, remainRange, err := hasEnoughEnergy(currRange, destRange, response)
+	b, remainRange, err := HasEnoughEnergy(currRange, destRange, response)
 	if !b || err != nil {
 		t.Errorf("Incorrect result generated for TesthasEnoughEnergyPositive1, return value is (%t, %v)", b, err)
 	}
@@ -29,12 +29,12 @@ func TestHasEnoughEnergyPositive1(t *testing.T) {
 
 func TestHasEnoughEnergyPositive2(t *testing.T) {
 	response := &route.Response{
-		Routes: []*route.Route{&route.Route{Distance: 10000.0}},
+		Routes: []*route.Route{{Distance: 10000.0}},
 	}
 
 	currRange := 10000.0
 	destRange := 5000.0
-	b, remainRange, err := hasEnoughEnergy(currRange, destRange, response)
+	b, remainRange, err := HasEnoughEnergy(currRange, destRange, response)
 	if b || err != nil {
 		t.Errorf("Incorrect result generated for TesthasEnoughEnergyPositive1, return value is (%t, %v)", b, err)
 	}

integration/service/oasis/reachable_by_multiple_charge.go → integration/service/oasis/selectionstrategy/reachable_by_multiple_charge.go

@@ -1,4 +1,4 @@
-package oasis
+package selectionstrategy
 
 import (
 	"encoding/json"
@@ -10,6 +10,8 @@ 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/spatialindexer/ranker"
+	"github.com/Telenav/osrm-backend/integration/service/oasis/stationconnquerier"
 	"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"
@@ -18,21 +20,43 @@ import (
 	"github.com/twpayne/go-polyline"
 )
 
+// GenerateSolutions4MultipleCharge generates solutions for multiple charge stations needed from orig to dest based on current energy status
 // @todo: handle negative situation
-func generateSolutions4MultipleCharge(w http.ResponseWriter, oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, finder stationfinder.StationFinder) {
-	solutions := generateSolutionsWithEarlistArrival(oasisReq, routeResp, oc, finder)
+func GenerateSolutions4MultipleCharge(w http.ResponseWriter, oasisReq *oasis.Request, routeResp *route.Response, resourceMgr *ResourceMgr) {
+	//solutions := generateSolutions4SearchAlongRoute(oasisReq, routeResp, resourceMgr.osrmConnector, resourceMgr.stationFinder)
+	solutions := generateSolutions4ChargeStationBasedRoute(oasisReq, resourceMgr)
 
 	w.WriteHeader(http.StatusOK)
 	r := new(oasis.Response)
 	r.Code = "200"
 	r.Message = "Success."
-	for _, sol := range solutions {
-		r.Solutions = append(r.Solutions, sol)
-	}
+	r.Solutions = append(r.Solutions, solutions...)
 	json.NewEncoder(w).Encode(r)
 }
 
-func generateSolutionsWithEarlistArrival(oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, finder stationfinder.StationFinder) []*oasis.Solution {
+func generateSolutions4ChargeStationBasedRoute(oasisReq *oasis.Request, resourceMgr *ResourceMgr) []*oasis.Solution {
+	targetSolutions := make([]*oasis.Solution, 0, 10)
+	querier := stationconnquerier.New(resourceMgr.spatialIndexerFinder,
+		ranker.CreateRanker(ranker.SimpleRanker, resourceMgr.osrmConnector),
+		resourceMgr.stationLocationQuerier,
+		resourceMgr.connectivityMap,
+		&nav.Location{Lat: oasisReq.Coordinates[0].Lat, Lon: oasisReq.Coordinates[0].Lon},
+		&nav.Location{Lat: oasisReq.Coordinates[1].Lat, Lon: oasisReq.Coordinates[1].Lon},
+		oasisReq.CurrRange,
+		oasisReq.MaxRange)
+	internalSolutions := stationgraph.NewStationGraph(oasisReq.CurrRange, oasisReq.MaxRange,
+		chargingstrategy.NewFakeChargingStrategy(oasisReq.MaxRange),
+		querier).GenerateChargeSolutions()
+
+	for _, sol := range internalSolutions {
+		targetSolution := sol.Convert2ExternalSolution()
+		targetSolutions = append(targetSolutions, targetSolution)
+	}
+
+	return targetSolutions
+}
+
+func generateSolutions4SearchAlongRoute(oasisReq *oasis.Request, routeResp *route.Response, oc *osrmconnector.OSRMConnector, finder stationfinder.StationFinder) []*oasis.Solution {
 	targetSolutions := make([]*oasis.Solution, 0)
 
 	chargeLocations := chargeLocationSelection(oasisReq, routeResp)

integration/service/oasis/reachable_by_multiple_charge_test.go → integration/service/oasis/selectionstrategy/reachable_by_multiple_charge_test.go

@@ -1,4 +1,4 @@
-package oasis
+package selectionstrategy
 
 import (
 	"testing"
@@ -9,42 +9,42 @@ import (
 
 var fakeRoute1 route.Route = route.Route{
 	Legs: []*route.Leg{
-		&route.Leg{
+		{
 			Distance: 37386.2,
 			Steps: []*route.Step{
-				&route.Step{
+				{
 					Distance: 449.5,
 					Geometry: "y~ecF|_qgVm@@kAJw@RqAf@a@PmBzAqA|Ae@v@a@|@aAzC",
 				},
-				&route.Step{
+				{
 					Distance: 243,
 					Geometry: "irfcFdqqgVEp@Ib@MZe@x@k@j@c@R_@Fm@DiBA",
 				},
-				&route.Step{
+				{
 					Distance: 207.7,
 					Geometry: "u|fcF|xqgV?zA?xA?h@?j@@tA?hA?h@",
 				},
-				&route.Step{
+				{
 					Distance: 344.6,
 					Geometry: "s|fcFrgrgV@h@tKHdA@t@@v@@",
 				},
-				&route.Step{
+				{
 					Distance: 28988.5,
 					Geometry: "gjfcFlirgVb@PZHZHj@PRJTJVRRTNXNd@DZ@\\A\\C`@Ih@Ih@Mn@Ot@OfA_@dDShAgA|FQ~@e@bCa@xBq@pDqB|K{@zEw@|Eq@vEO~@ANKr@EZGh@G`@[|Bm@hE_@fCIn@E^EZYpBw@bGM|@_AdHgBzN_@rCa@`CETCPIn@yAxKq@bFy@hGIh@e@fDKx@UbBCRId@Id@G`@}@dHy@tGKp@Kv@UdBIl@k@bEgAnIIt@Ih@Ip@If@YjBa@tCGf@Il@q@zEKv@g@rDuAfKg@xDsA~JyAxKOlAIp@QrAObAOjAKt@Kz@_@tCm@bEYpBUpA_@xBg@xCWtAa@|BYxAIb@AJMx@UtAa@~BUdBQjA_AdHqBhOYvBq@dFc@hDwAdKMz@Ir@Ib@Kt@QvAKp@]xBS~@g@nBIVIZYdAMb@q@bCK^k@jBcA`DcAbDaA`D{@jCQl@KXy@rC_A`Dc@|AOh@g@`Bw@fCK^cAxDSr@cAnDQj@Sn@w@dCu@jBGNiAzB[j@[j@aAdBINGJgAdBc@p@s@bAiAdBeAbBuB`DMPkDpFsCjEe@t@aCpD_@l@Yb@aBdCoAnBOR_AnASVOTGHMPu@jAiAdBm@`A_FzH_CnDqAlBaAvAy@bA_AjAGF_CtCcFlFeBjBkCrC[ZUVu@v@_@^mArAg@h@oCvC_@`@{C~CoArAqArASTqBtBgAjA}@`A{A~Ag@h@YZq@r@gCjCwB|BkDtDcBfBuHdIyA|AkAnAOPsAtAqAtA]^WXWX}@`Ae@f@QPcGnGoApAoCxCeHtHeJrJg@h@qAvA{FdGONMLoDvDs@v@oCzCg@l@w@~@cArAeAzA[f@]l@QXcB|Ci@hAs@zAm@lAs@xAs@xAaBjDeChFiD`HaDjGUb@qBhEsAtC_@t@iBpD[n@wArCwAtCwCjGS`@oCpFoCrFgAxBc@|@cAlBu@vA}@pBs@xAuEjJyAxCgG`MmBzDaAnBc@z@q@rAo@rAsAjCy@`BKXITIPkA|BkAbCeBjD_AjBe@~@y@dBk@fAmBzDqEdJcKpSWh@Sb@kA~BINGLs@vAq@tAwDvHeBlD{@dBmBzDe@`AKRo@tA_@v@Yh@cAnBcApBi@fA_CvEyA|Cm@pAuBlEm@tAu@lBo@|AkAlDABOh@CJCJCHGPADITSr@CJGTENe@dBi@zBw@|D[hBG\\[bB{@dFO~@G`@c@zDUhBQdBO`B]bEC^OxBcAzOiBbZIjAc@bH}@lN{@~MMtBw@bMUxCKpAY~Ck@|EGh@a@xCOfAIf@Id@Ib@Mx@Kn@Q`AG\\G\\Mh@I^Qv@Ml@i@tBW`AYfAQn@i@fBm@pBk@nB_@hAk@fBOd@eArCwBlGo@hBOb@Qf@}@jC_AlCs@tBs@~Bs@zBe@bBUx@U`AW`AU`AUdAU`A[vA[xA]hBId@Id@I`@UdAIl@]jBqC~Ne@bCKh@Kj@Q~@Mj@Kj@a@nBYtAMr@Mh@Oj@e@~Aw@`Cg@pAo@vAgAvBgAlBg@p@s@~@cBrBeE~EmAvAcAjAsA|AwChDiBvB{AhBuFvG{CpDaAhAcF`GeJrKyJhLu@|@ePnR]`@WZoAvAsEpFyFxGg@l@}@dAoAvA_BlByAdBqAzAcE|EoAzAcAjAqEjFyEtF{@bAe@h@",
 				},
-				&route.Step{
+				{
 					Distance: 467.2,
 					Geometry: "mx_dFbfgiVcAv@s@j@WV[\\eA`Am@h@]V[R[JYF_@D]@yAG[?W@UDUFSHSLQLc@`@",
 				},
-				&route.Step{
+				{
 					Distance: 6035.5,
 					Geometry: "so`dF`sgiVGf@NVR\\RZv@jAZf@LTV^RXl@~@b@r@`@n@TXRV~@dA^^d@b@VRFFTPf@\\BB^VXN`@TRJ\\R`Ah@`@TRJ`@NVLTLd@b@\\`@HJVXNJVLLPNPX^X^RVTVRVTVLPNPNPLPX\\RRLNNRZ^XZd@n@LPZ^DFBDRVr@z@RPZRJDPHXHj@JnATF@h@Jd@PPHd@ZPRPVR^LXNl@@HHr@Bb@Bb@@^B\\JbCBb@D`ADl@Dp@Dn@@XDf@DTHTLZV^JNPRVR\\VFDf@ZLHXNVXb@|@Rx@@DLp@Ln@ZbBXxADPRfAb@zBNv@Jj@FZR~@RpA`@bCLx@Nx@FVP~@^rBZ|AJh@DRf@fCJf@BNJd@RdA?P?DDRDVF`@Jf@FZJf@FZFZLn@FVFXX~AHb@Hb@Pz@Pz@Jd@PbARbALz@BNFd@B`@@f@@z@?~B?R?\\?x@?p@?lC?Z@l@Dz@Dx@?l@A|@Et@Kv@Kh@Md@Ob@MXEHMTQZ]n@KRKROZEHABQf@I\\GVETCNG^En@A`@Ad@@b@Dx@D|@@\\@b@@^@^?j@@dA?\\@f@Ax@A^Cj@Iz@APE`@E`@Gj@Gh@I`AEj@Cj@AnABdAFfAFz@Fl@Fp@BRH|@L~AFl@BVFl@BXDb@HbA^`FHjAz@hKDh@Fr@Ht@Hv@P~AFv@Hx@HfADj@B`@Dr@F|@Bl@Bj@@f@@`A?bAAx@Ez@IhAIx@UfBKx@Gr@UxCUxCCXEl@Eb@C^E`@C`@Gl@KdAGn@",
 				},
-				&route.Step{
+				{
 					Distance: 650.3,
 					Geometry: "aq}cFfesiVK^OXQLQDy@@O?OBYLeAr@[N_@Fa@DUAu@IcAOSCe@Em@Ei@?mA@u@Bo@Dg@Jk@Vw@PcAZcA`@KF",
 				},
-				&route.Step{
+				{
 					Distance: 0,
 					Geometry: "os~cFvmsiV",
 				},

integration/service/oasis/reachable_by_single_charge.go → integration/service/oasis/selectionstrategy/reachable_by_single_charge.go

@@ -1,4 +1,4 @@
-package oasis
+package selectionstrategy
 
 import (
 	"encoding/json"
@@ -12,7 +12,6 @@ import (
 	"github.com/Telenav/osrm-backend/integration/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/stationfinder"
 	"github.com/Telenav/osrm-backend/integration/service/oasis/stationfinder/stationfinderalg"
 	"github.com/golang/glog"
 )
@@ -25,14 +24,14 @@ 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, finder stationfinder.StationFinder) osrm.Coordinates {
+func GetOverlapChargeStations4OrigDest(req *oasis.Request, routedistance float64, resourceMgr *ResourceMgr) osrm.Coordinates {
 	// only possible when currRange + maxRange > distance + safeRange
 	if req.CurrRange+req.MaxRange < routedistance+req.SafeLevel {
 		return nil
 	}
 
-	origStations := finder.NewOrigStationFinder(req)
-	destStations := finder.NewDestStationFinder(req)
+	origStations := resourceMgr.stationFinder.NewOrigStationFinder(req)
+	destStations := resourceMgr.stationFinder.NewDestStationFinder(req)
 	overlap := stationfinderalg.FindOverlapBetweenStations(origStations, destStations)
 
 	if len(overlap) == 0 {
@@ -61,9 +60,9 @@ type singleChargeStationCandidate struct {
 	durationToDest   float64
 }
 
-// @todo these logic might refactored later: charge station status calculation should be moved away
-func generateResponse4SingleChargeStation(w http.ResponseWriter, req *oasis.Request, overlapPoints osrm.Coordinates, osrmConnector *osrmconnector.OSRMConnector) bool {
-	candidate, err := pickChargeStationWithEarlistArrival(req, overlapPoints, osrmConnector)
+// GenerateResponse4SingleChargeStation generates response for only single charge station needed from orig to dest based on current energy status
+func GenerateResponse4SingleChargeStation(w http.ResponseWriter, req *oasis.Request, overlapPoints osrm.Coordinates, resourceMgr *ResourceMgr) bool {
+	candidate, err := pickChargeStationWithEarlistArrival(req, overlapPoints, resourceMgr.osrmConnector)
 
 	if err != nil {
 		w.WriteHeader(http.StatusOK)

integration/service/oasis/reachable_by_single_charge_test.go → integration/service/oasis/selectionstrategy/reachable_by_single_charge_test.go

@@ -1,4 +1,4 @@
-package oasis
+package selectionstrategy
 
 import (
 	"testing"