blob: 92ec6ae84c4e1cf9a7bb3782885dbcaa81180649 [file] [log] [blame]
// +build ignore,OMIT
// The backend command runs a Google server that returns fake results.
package main
import (
"flag"
"fmt"
"log"
"math/rand"
"net"
"net/http"
_ "net/http/pprof"
"time"
"golang.org/x/net/context"
"golang.org/x/net/trace"
pb "golang.org/x/talks/content/2015/gotham-grpc/search"
"google.golang.org/grpc"
)
var (
index = flag.Int("index", 0, "RPC port is 36061+index; debug port is 36661+index")
)
type server struct{}
// randomDuration returns a random duration up to max, at intervals of max/10.
func randomDuration(max time.Duration) time.Duration {
return time.Duration(1+int64(rand.Intn(10))) * (max / 10)
}
// Search sleeps for a random interval then returns a string
// identifying the query and this backend.
func (s *server) Search(ctx context.Context, req *pb.Request) (*pb.Result, error) { // HL
d := randomDuration(100 * time.Millisecond)
logSleep(ctx, d) // HL
select {
case <-time.After(d):
return &pb.Result{ // HL
Title: fmt.Sprintf("result for [%s] from backend %d", req.Query, *index), // HL
}, nil // HL
case <-ctx.Done():
return nil, ctx.Err()
}
}
func logSleep(ctx context.Context, d time.Duration) {
if tr, ok := trace.FromContext(ctx); ok { // HL
tr.LazyPrintf("sleeping for %s", d) // HL
}
}
// Watch returns a stream of results identifying the query and this
// backend, sleeping a random interval between each send.
func (s *server) Watch(req *pb.Request, stream pb.Google_WatchServer) error { // HL
ctx := stream.Context()
for i := 0; ; i++ {
d := randomDuration(1 * time.Second)
logSleep(ctx, d) // HL
select {
case <-time.After(d):
err := stream.Send(&pb.Result{ // HL
Title: fmt.Sprintf("result %d for [%s] from backend %d", i, req.Query, *index), // HL
}) // HL
if err != nil {
return err
}
case <-ctx.Done():
return ctx.Err()
}
}
}
func main() {
flag.Parse()
rand.Seed(time.Now().UnixNano())
go http.ListenAndServe(fmt.Sprintf(":%d", 36661+*index), nil) // HTTP debugging
lis, err := net.Listen("tcp", fmt.Sprintf(":%d", 36061+*index)) // RPC port // HL
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
g := grpc.NewServer() // HL
pb.RegisterGoogleServer(g, new(server)) // HL
g.Serve(lis) // HL
}