github.com/gdamore/mangos@v1.4.0/examples/pair/pair.go (about)

     1  // Copyright 2018 The Mangos Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use file except in compliance with the License.
     5  // You may obtain a copy of the license at
     6  //
     7  //    http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // pair implements a pair example.  node0 is a listening
    16  // pair socket, and node1 is a dialing pair socket.
    17  //
    18  // To use:
    19  //
    20  //   $ go build .
    21  //   $ url=tcp://127.0.0.1:40899
    22  //   $ ./pair node0 $url & node0=$!
    23  //   $ ./pair node1 $url & node1=$!
    24  //   $ sleep 3
    25  //   $ kill $node0 $node1
    26  //
    27  package main
    28  
    29  import (
    30  	"fmt"
    31  	"os"
    32  	"time"
    33  
    34  	"nanomsg.org/go-mangos"
    35  	"nanomsg.org/go-mangos/protocol/pair"
    36  	"nanomsg.org/go-mangos/transport/ipc"
    37  	"nanomsg.org/go-mangos/transport/tcp"
    38  )
    39  
    40  func die(format string, v ...interface{}) {
    41  	fmt.Fprintln(os.Stderr, fmt.Sprintf(format, v...))
    42  	os.Exit(1)
    43  }
    44  
    45  func sendName(sock mangos.Socket, name string) {
    46  	fmt.Printf("%s: SENDING \"%s\"\n", name, name)
    47  	if err := sock.Send([]byte(name)); err != nil {
    48  		die("failed sending: %s", err)
    49  	}
    50  }
    51  
    52  func recvName(sock mangos.Socket, name string) {
    53  	var msg []byte
    54  	var err error
    55  	if msg, err = sock.Recv(); err == nil {
    56  		fmt.Printf("%s: RECEIVED: \"%s\"\n", name, string(msg))
    57  	}
    58  }
    59  
    60  func sendRecv(sock mangos.Socket, name string) {
    61  	for {
    62  		sock.SetOption(mangos.OptionRecvDeadline, 100*time.Millisecond)
    63  		recvName(sock, name)
    64  		time.Sleep(time.Second)
    65  		sendName(sock, name)
    66  	}
    67  }
    68  
    69  func node0(url string) {
    70  	var sock mangos.Socket
    71  	var err error
    72  	if sock, err = pair.NewSocket(); err != nil {
    73  		die("can't get new pair socket: %s", err)
    74  	}
    75  	sock.AddTransport(ipc.NewTransport())
    76  	sock.AddTransport(tcp.NewTransport())
    77  	if err = sock.Listen(url); err != nil {
    78  		die("can't listen on pair socket: %s", err.Error())
    79  	}
    80  	sendRecv(sock, "node0")
    81  }
    82  
    83  func node1(url string) {
    84  	var sock mangos.Socket
    85  	var err error
    86  
    87  	if sock, err = pair.NewSocket(); err != nil {
    88  		die("can't get new pair socket: %s", err.Error())
    89  	}
    90  	sock.AddTransport(ipc.NewTransport())
    91  	sock.AddTransport(tcp.NewTransport())
    92  	if err = sock.Dial(url); err != nil {
    93  		die("can't dial on pair socket: %s", err.Error())
    94  	}
    95  	sendRecv(sock, "node1")
    96  }
    97  
    98  func main() {
    99  	if len(os.Args) > 2 && os.Args[1] == "node0" {
   100  		node0(os.Args[2])
   101  		os.Exit(0)
   102  	}
   103  	if len(os.Args) > 2 && os.Args[1] == "node1" {
   104  		node1(os.Args[2])
   105  		os.Exit(0)
   106  	}
   107  	fmt.Fprintf(os.Stderr, "Usage: pair node0|node1 <URL>\n")
   108  	os.Exit(1)
   109  }