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/*
*
* Copyright 2015 gRPC authors.
*
* 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.
*
*/
//go:generate protoc -I ../routeguide --go_out=plugins=grpc:../routeguide ../routeguide/route_guide.proto
// Package main implements a simple gRPC server that demonstrates how to use gRPC-Go libraries
// to perform unary, client streaming, server streaming and full duplex RPCs.
//
// It implements the route guide service whose definition can be found in routeguide/route_guide.proto.
package main
import (
"encoding/json"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"math"
"net"
"sync"
"time"
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/testdata"
"github.com/golang/protobuf/proto"
pb "google.golang.org/grpc/examples/route_guide/routeguide"
)
var (
tls = flag.Bool("tls", false, "Connection uses TLS if true, else plain TCP")
certFile = flag.String("cert_file", "", "The TLS cert file")
keyFile = flag.String("key_file", "", "The TLS key file")
jsonDBFile = flag.String("json_db_file", "testdata/route_guide_db.json", "A json file containing a list of features")
port = flag.Int("port", 10000, "The server port")
)
type routeGuideServer struct {
savedFeatures []*pb.Feature // read-only after initialized
mu sync.Mutex // protects routeNotes
routeNotes map[string][]*pb.RouteNote
}
// GetFeature returns the feature at the given point.
func (s *routeGuideServer) GetFeature(ctx context.Context, point *pb.Point) (*pb.Feature, error) {
for _, feature := range s.savedFeatures {
if proto.Equal(feature.Location, point) {
return feature, nil
}
}
// No feature was found, return an unnamed feature
return &pb.Feature{Location: point}, nil
}
// ListFeatures lists all features contained within the given bounding Rectangle.
func (s *routeGuideServer) ListFeatures(rect *pb.Rectangle, stream pb.RouteGuide_ListFeaturesServer) error {
for _, feature := range s.savedFeatures {
if inRange(feature.Location, rect) {
if err := stream.Send(feature); err != nil {
return err
}
}
}
return nil
}
// RecordRoute records a route composited of a sequence of points.
//
// It gets a stream of points, and responds with statistics about the "trip":
// number of points, number of known features visited, total distance traveled, and
// total time spent.
func (s *routeGuideServer) RecordRoute(stream pb.RouteGuide_RecordRouteServer) error {
var pointCount, featureCount, distance int32
var lastPoint *pb.Point
startTime := time.Now()
for {
point, err := stream.Recv()
if err == io.EOF {
endTime := time.Now()
return stream.SendAndClose(&pb.RouteSummary{
PointCount: pointCount,
FeatureCount: featureCount,
Distance: distance,
ElapsedTime: int32(endTime.Sub(startTime).Seconds()),
})
}
if err != nil {
return err
}
pointCount++
for _, feature := range s.savedFeatures {
if proto.Equal(feature.Location, point) {
featureCount++
}
}
if lastPoint != nil {
distance += calcDistance(lastPoint, point)
}
lastPoint = point
}
}
// RouteChat receives a stream of message/location pairs, and responds with a stream of all
// previous messages at each of those locations.
func (s *routeGuideServer) RouteChat(stream pb.RouteGuide_RouteChatServer) error {
for {
in, err := stream.Recv()
if err == io.EOF {
return nil
}
if err != nil {
return err
}
key := serialize(in.Location)
s.mu.Lock()
s.routeNotes[key] = append(s.routeNotes[key], in)
// Note: this copy prevents blocking other clients while serving this one.
// We don't need to do a deep copy, because elements in the slice are
// insert-only and never modified.
rn := make([]*pb.RouteNote, len(s.routeNotes[key]))
copy(rn, s.routeNotes[key])
s.mu.Unlock()
for _, note := range rn {
if err := stream.Send(note); err != nil {
return err
}
}
}
}
// loadFeatures loads features from a JSON file.
func (s *routeGuideServer) loadFeatures(filePath string) {
file, err := ioutil.ReadFile(filePath)
if err != nil {
log.Fatalf("Failed to load default features: %v", err)
}
if err := json.Unmarshal(file, &s.savedFeatures); err != nil {
log.Fatalf("Failed to load default features: %v", err)
}
}
func toRadians(num float64) float64 {
return num * math.Pi / float64(180)
}
// calcDistance calculates the distance between two points using the "haversine" formula.
// The formula is based on http://mathforum.org/library/drmath/view/51879.html.
func calcDistance(p1 *pb.Point, p2 *pb.Point) int32 {
const CordFactor float64 = 1e7
const R float64 = float64(6371000) // earth radius in metres
lat1 := toRadians(float64(p1.Latitude) / CordFactor)
lat2 := toRadians(float64(p2.Latitude) / CordFactor)
lng1 := toRadians(float64(p1.Longitude) / CordFactor)
lng2 := toRadians(float64(p2.Longitude) / CordFactor)
dlat := lat2 - lat1
dlng := lng2 - lng1
a := math.Sin(dlat/2)*math.Sin(dlat/2) +
math.Cos(lat1)*math.Cos(lat2)*
math.Sin(dlng/2)*math.Sin(dlng/2)
c := 2 * math.Atan2(math.Sqrt(a), math.Sqrt(1-a))
distance := R * c
return int32(distance)
}
func inRange(point *pb.Point, rect *pb.Rectangle) bool {
left := math.Min(float64(rect.Lo.Longitude), float64(rect.Hi.Longitude))
right := math.Max(float64(rect.Lo.Longitude), float64(rect.Hi.Longitude))
top := math.Max(float64(rect.Lo.Latitude), float64(rect.Hi.Latitude))
bottom := math.Min(float64(rect.Lo.Latitude), float64(rect.Hi.Latitude))
if float64(point.Longitude) >= left &&
float64(point.Longitude) <= right &&
float64(point.Latitude) >= bottom &&
float64(point.Latitude) <= top {
return true
}
return false
}
func serialize(point *pb.Point) string {
return fmt.Sprintf("%d %d", point.Latitude, point.Longitude)
}
func newServer() *routeGuideServer {
s := &routeGuideServer{routeNotes: make(map[string][]*pb.RouteNote)}
s.loadFeatures(*jsonDBFile)
return s
}
func main() {
flag.Parse()
lis, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", *port))
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
var opts []grpc.ServerOption
if *tls {
if *certFile == "" {
*certFile = testdata.Path("server1.pem")
}
if *keyFile == "" {
*keyFile = testdata.Path("server1.key")
}
creds, err := credentials.NewServerTLSFromFile(*certFile, *keyFile)
if err != nil {
log.Fatalf("Failed to generate credentials %v", err)
}
opts = []grpc.ServerOption{grpc.Creds(creds)}
}
grpcServer := grpc.NewServer(opts...)
pb.RegisterRouteGuideServer(grpcServer, newServer())
grpcServer.Serve(lis)
}