gRPC 框架入门

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syntax = "proto3";

option go_package = "./protos";

package routeguide;

// Interface exported by the server.
service RouteGuide {
  // A simple RPC.
  //
  // Obtains the feature at a given position.
  //
  // A feature with an empty name is returned if there's no feature at the given
  // position.
  rpc GetFeature(Point) returns (Feature) {}

  // A server-to-client streaming RPC.
  //
  // Obtains the Features available within the given Rectangle.  Results are
  // streamed rather than returned at once (e.g. in a response message with a
  // repeated field), as the rectangle may cover a large area and contain a
  // huge number of features.
  rpc ListFeatures(Rectangle) returns (stream Feature) {}

  // A client-to-server streaming RPC.
  //
  // Accepts a stream of Points on a route being traversed, returning a
  // RouteSummary when traversal is completed.
  rpc RecordRoute(stream Point) returns (RouteSummary) {}

  // A Bidirectional streaming RPC.
  //
  // Accepts a stream of RouteNotes sent while a route is being traversed,
  // while receiving other RouteNotes (e.g. from other users).
  rpc RouteChat(stream RouteNote) returns (stream RouteNote) {}
}

// Points are represented as latitude-longitude pairs in the E7 representation
// (degrees multiplied by 10**7 and rounded to the nearest integer).
// Latitudes should be in the range +/- 90 degrees and longitude should be in
// the range +/- 180 degrees (inclusive).
message Point {
  int32 latitude = 1;
  int32 longitude = 2;
}

// A latitude-longitude rectangle, represented as two diagonally opposite
// points "lo" and "hi".
message Rectangle {
  // One corner of the rectangle.
  Point lo = 1;

  // The other corner of the rectangle.
  Point hi = 2;
}

// A feature names something at a given point.
//
// If a feature could not be named, the name is empty.
message Feature {
  // The name of the feature.
  string name = 1;

  // The point where the feature is detected.
  Point location = 2;
}

// A RouteNote is a message sent while at a given point.
message RouteNote {
  // The location from which the message is sent.
  Point location = 1;

  // The message to be sent.
  string message = 2;
}

// A RouteSummary is received in response to a RecordRoute rpc.
//
// It contains the number of individual points received, the number of
// detected features, and the total distance covered as the cumulative sum of
// the distance between each point.
message RouteSummary {
  // The number of points received.
  int32 point_count = 1;

  // The number of known features passed while traversing the route.
  int32 feature_count = 2;

  // The distance covered in metres.
  int32 distance = 3;

  // The duration of the traversal in seconds.
  int32 elapsed_time = 4;
}

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$ python -m pip install grpcio

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$ python -m pip install grpcio-tools

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$ python -m grpc_tools.protoc -I. --python_out=. --grpc_python_out=. route_guide.proto

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"""The Python implementation of the gRPC route guide server."""

from concurrent import futures
import logging
import math
import time

import grpc
import route_guide_pb2
import route_guide_pb2_grpc
import route_guide_resources


def get_feature(feature_db, point):
    """Returns Feature at given location or None."""
    for feature in feature_db:
        if feature.location == point:
            return feature
    return None


def get_distance(start, end):
    """Distance between two points."""
    coord_factor = 10000000.0
    lat_1 = start.latitude / coord_factor
    lat_2 = end.latitude / coord_factor
    lon_1 = start.longitude / coord_factor
    lon_2 = end.longitude / coord_factor
    lat_rad_1 = math.radians(lat_1)
    lat_rad_2 = math.radians(lat_2)
    delta_lat_rad = math.radians(lat_2 - lat_1)
    delta_lon_rad = math.radians(lon_2 - lon_1)

    # Formula is based on http://mathforum.org/library/drmath/view/51879.html
    a = (pow(math.sin(delta_lat_rad / 2), 2) +
         (math.cos(lat_rad_1) * math.cos(lat_rad_2) *
          pow(math.sin(delta_lon_rad / 2), 2)))
    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
    R = 6371000
    # metres
    return R * c


class RouteGuideServicer(route_guide_pb2_grpc.RouteGuideServicer):
    """Provides methods that implement functionality of route guide server."""

    def __init__(self):
        self.db = route_guide_resources.read_route_guide_database()

    def GetFeature(self, request, context):
        feature = get_feature(self.db, request)
        if feature is None:
            return route_guide_pb2.Feature(name="", location=request)
        else:
            return feature

    def ListFeatures(self, request, context):
        left = min(request.lo.longitude, request.hi.longitude)
        right = max(request.lo.longitude, request.hi.longitude)
        top = max(request.lo.latitude, request.hi.latitude)
        bottom = min(request.lo.latitude, request.hi.latitude)
        for feature in self.db:
            if (feature.location.longitude>= left and
                    feature.location.longitude <= right and
                    feature.location.latitude >= bottom and
                    feature.location.latitude <= top):
                yield feature

    def RecordRoute(self, request_iterator, context):
        point_count = 0
        feature_count = 0
        distance = 0.0
        prev_point = None

        start_time = time.time()
        for point in request_iterator:
            point_count += 1
            if get_feature(self.db, point):
                feature_count += 1
            if prev_point:
                distance += get_distance(prev_point, point)
            prev_point = point

        elapsed_time = time.time() - start_time
        return route_guide_pb2.RouteSummary(point_count=point_count,
                                            feature_count=feature_count,
                                            distance=int(distance),
                                            elapsed_time=int(elapsed_time))

    def RouteChat(self, request_iterator, context):
        prev_notes = []
        for new_note in request_iterator:
            for prev_note in prev_notes:
                if prev_note.location == new_note.location:
                    yield prev_note
            prev_notes.append(new_note)


def serve():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    route_guide_pb2_grpc.add_RouteGuideServicer_to_server(
        RouteGuideServicer(), server)
    server.add_insecure_port('[::]:50051')
    server.start()
    server.wait_for_termination()


if __name__ == '__main__':
    logging.basicConfig()
    serve()

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"""The Python implementation of the gRPC route guide client."""

from __future__ import print_function

import logging
import random

import grpc
import route_guide_pb2
import route_guide_pb2_grpc
import route_guide_resources


def make_route_note(message, latitude, longitude):
    return route_guide_pb2.RouteNote(
        message=message,
        location=route_guide_pb2.Point(latitude=latitude, longitude=longitude))


def guide_get_one_feature(stub, point):
    feature = stub.GetFeature(point)
    if not feature.location:
        print("Server returned incomplete feature")
        return

    if feature.name:
        print("Feature called %s at %s" % (feature.name, feature.location))
    else:
        print("Found no feature at %s" % feature.location)


def guide_get_feature(stub):
    guide_get_one_feature(
        stub, route_guide_pb2.Point(latitude=409146138, longitude=-746188906))
    guide_get_one_feature(stub, route_guide_pb2.Point(latitude=0, longitude=0))


def guide_list_features(stub):
    rectangle = route_guide_pb2.Rectangle(
        lo=route_guide_pb2.Point(latitude=400000000, longitude=-750000000),
        hi=route_guide_pb2.Point(latitude=420000000, longitude=-730000000))
    print("Looking for features between 40, -75 and 42, -73")

    features = stub.ListFeatures(rectangle)

    for feature in features:
        print("Feature called %s at %s" % (feature.name, feature.location))


def generate_route(feature_list):
    for _ in range(0, 10):
        random_feature = feature_list[random.randint(0, len(feature_list) - 1)]
        print("Visiting point %s" % random_feature.location)
        yield random_feature.location


def guide_record_route(stub):
    feature_list = route_guide_resources.read_route_guide_database()

    route_iterator = generate_route(feature_list)
    route_summary = stub.RecordRoute(route_iterator)
    print("Finished trip with %s points" % route_summary.point_count)
    print("Passed %s features" % route_summary.feature_count)
    print("Travelled %s meters" % route_summary.distance)
    print("It took %s seconds" % route_summary.elapsed_time)


def generate_messages():
    messages = [
        make_route_note("First message", 0, 0),
        make_route_note("Second message", 0, 1),
        make_route_note("Third message", 1, 0),
        make_route_note("Fourth message", 0, 0),
        make_route_note("Fifth message", 1, 0),
    ]
    for msg in messages:
        print("Sending %s at %s" % (msg.message, msg.location))
        yield msg


def guide_route_chat(stub):
    responses = stub.RouteChat(generate_messages())
    for response in responses:
        print("Received message %s at %s" %
              (response.message, response.location))


def run():
    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
    # used in circumstances in which the with statement does not fit the needs
    # of the code.
    with grpc.insecure_channel('localhost:50051') as channel:
        stub = route_guide_pb2_grpc.RouteGuideStub(channel)
        print("-------------- GetFeature --------------")
        guide_get_feature(stub)
        print("-------------- ListFeatures --------------")
        guide_list_features(stub)
        print("-------------- RecordRoute --------------")
        guide_record_route(stub)
        print("-------------- RouteChat --------------")
        guide_route_chat(stub)


if __name__ == '__main__':
    logging.basicConfig()
    run()

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$ go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.28
$ go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.2

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$ protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative route_guide.proto

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// 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 (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"math"
	"net"
	"sync"
	"time"

	"google.golang.org/grpc"

	"google.golang.org/grpc/credentials"
	"google.golang.org/grpc/examples/data"

	"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", "","A json file containing a list of features")
	port       = flag.Int("port", 50051, "The server port")
)

type routeGuideServer struct {
	pb.UnimplementedRouteGuideServer
	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) {
	var data []byte
	if filePath != "" {
		var err error
		data, err = ioutil.ReadFile(filePath)
		if err != nil {
			log.Fatalf("Failed to load default features: %v", err)
		}
	} else {
		data = exampleData
	}
	if err := json.Unmarshal(data, &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(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 = data.Path("x509/server_cert.pem")
		}
		if *keyFile == "" {
			*keyFile = data.Path("x509/server_key.pem")
		}
		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)
}

// exampleData is a copy of testdata/route_guide_db.json. It's to avoid
// specifying file path with `go run`.
var exampleData = []byte(`[{
    "location": {
        "latitude": 407838351,
        "longitude": -746143763
    },
    "name": "Patriots Path, Mendham, NJ 07945, USA"
})

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// Package main implements a simple gRPC client that demonstrates how to use gRPC-Go libraries
// to perform unary, client streaming, server streaming and full duplex RPCs.
//
// It interacts with the route guide service whose definition can be found in routeguide/route_guide.proto.
package main

import (
	"context"
	"flag"
	"io"
	"log"
	"math/rand"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/grpc/examples/data"
	pb "google.golang.org/grpc/examples/route_guide/routeguide"
)

var (
	tls                = flag.Bool("tls", false, "Connection uses TLS if true, else plain TCP")
	caFile             = flag.String("ca_file", "","The file containing the CA root cert file")
	serverAddr         = flag.String("addr", "localhost:50051", "The server address in the format of host:port")
	serverHostOverride = flag.String("server_host_override", "x.test.example.com", "The server name used to verify the hostname returned by the TLS handshake")
)

// printFeature gets the feature for the given point.
func printFeature(client pb.RouteGuideClient, point *pb.Point) {
	log.Printf("Getting feature for point (%d, %d)", point.Latitude, point.Longitude)
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	feature, err := client.GetFeature(ctx, point)
	if err != nil {
		log.Fatalf("client.GetFeature failed: %v", err)
	}
	log.Println(feature)
}

// printFeatures lists all the features within the given bounding Rectangle.
func printFeatures(client pb.RouteGuideClient, rect *pb.Rectangle) {
	log.Printf("Looking for features within %v", rect)
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	stream, err := client.ListFeatures(ctx, rect)
	if err != nil {
		log.Fatalf("client.ListFeatures failed: %v", err)
	}
	for {
		feature, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Fatalf("client.ListFeatures failed: %v", err)
		}
		log.Printf("Feature: name: %q, point:(%v, %v)", feature.GetName(),
			feature.GetLocation().GetLatitude(), feature.GetLocation().GetLongitude())
	}
}

// runRecordRoute sends a sequence of points to server and expects to get a RouteSummary from server.
func runRecordRoute(client pb.RouteGuideClient) {
	// Create a random number of random points
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	pointCount := int(r.Int31n(100)) + 2 // Traverse at least two points
	var points []*pb.Point
	for i := 0; i < pointCount; i++ {
		points = append(points, randomPoint(r))
	}
	log.Printf("Traversing %d points.", len(points))
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	stream, err := client.RecordRoute(ctx)
	if err != nil {
		log.Fatalf("client.RecordRoute failed: %v", err)
	}
	for _, point := range points {
		if err := stream.Send(point); err != nil {
			log.Fatalf("client.RecordRoute: stream.Send(%v) failed: %v", point, err)
		}
	}
	reply, err := stream.CloseAndRecv()
	if err != nil {
		log.Fatalf("client.RecordRoute failed: %v", err)
	}
	log.Printf("Route summary: %v", reply)
}

// runRouteChat receives a sequence of route notes, while sending notes for various locations.
func runRouteChat(client pb.RouteGuideClient) {
	notes := []*pb.RouteNote{
		{Location: &pb.Point{Latitude: 0, Longitude: 1}, Message: "First message"},
		{Location: &pb.Point{Latitude: 0, Longitude: 2}, Message: "Second message"},
		{Location: &pb.Point{Latitude: 0, Longitude: 3}, Message: "Third message"},
		{Location: &pb.Point{Latitude: 0, Longitude: 1}, Message: "Fourth message"},
		{Location: &pb.Point{Latitude: 0, Longitude: 2}, Message: "Fifth message"},
		{Location: &pb.Point{Latitude: 0, Longitude: 3}, Message: "Sixth message"},
	}
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	stream, err := client.RouteChat(ctx)
	if err != nil {
		log.Fatalf("client.RouteChat failed: %v", err)
	}
	waitc := make(chan struct{})
	go func() {
		for {
			in, err := stream.Recv()
			if err == io.EOF {
				// read done.
				close(waitc)
				return
			}
			if err != nil {
				log.Fatalf("client.RouteChat failed: %v", err)
			}
			log.Printf("Got message %s at point(%d, %d)", in.Message, in.Location.Latitude, in.Location.Longitude)
		}
	}()
	for _, note := range notes {
		if err := stream.Send(note); err != nil {
			log.Fatalf("client.RouteChat: stream.Send(%v) failed: %v", note, err)
		}
	}
	stream.CloseSend()
	<-waitc
}

func randomPoint(r *rand.Rand) *pb.Point {
	lat := (r.Int31n(180) - 90) * 1e7
	long := (r.Int31n(360) - 180) * 1e7
	return &pb.Point{Latitude: lat, Longitude: long}
}

func main() {
	flag.Parse()
	var opts []grpc.DialOption
	if *tls {
		if *caFile == "" {
			*caFile = data.Path("x509/ca_cert.pem")
		}
		creds, err := credentials.NewClientTLSFromFile(*caFile, *serverHostOverride)
		if err != nil {
			log.Fatalf("Failed to create TLS credentials %v", err)
		}
		opts = append(opts, grpc.WithTransportCredentials(creds))
	} else {
		opts = append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()))
	}

	conn, err := grpc.Dial(*serverAddr, opts...)
	if err != nil {
		log.Fatalf("fail to dial: %v", err)
	}
	defer conn.Close()
	client := pb.NewRouteGuideClient(conn)

	// Looking for a valid feature
	printFeature(client, &pb.Point{Latitude: 409146138, Longitude: -746188906})

	// Feature missing.
	printFeature(client, &pb.Point{Latitude: 0, Longitude: 0})

	// Looking for features between 40, -75 and 42, -73.
	printFeatures(client, &pb.Rectangle{
		Lo: &pb.Point{Latitude: 400000000, Longitude: -400000000},
		Hi: &pb.Point{Latitude: 420000000, Longitude: -730000000},
	})

	// RecordRoute
	runRecordRoute(client)

	// RouteChat
	runRouteChat(client)
}