github.com/gdamore/mangos@v1.4.0/examples/bus/bus.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  // bus implements a bus example.
    16  //
    17  // To use:
    18  //
    19  //   $ go build .
    20  //   $ url0=tcp://127.0.0.1:40890
    21  //   $ url1=tcp://127.0.0.1:40891
    22  //   $ url2=tcp://127.0.0.1:40892
    23  //   $ url3=tcp://127.0.0.1:40893
    24  //   $ ./bus node0 $url0 $url1 $url2 & node0=$!
    25  //   $ ./bus node1 $url1 $url2 $url3 & node1=$!
    26  //   $ ./bus node2 $url2 $url3 & node2=$!
    27  //   $ ./bus node3 $url3 $url0 & node3=$!
    28  //   $ sleep 5
    29  //   $ kill $node0 $node1 $node2 $node3
    30  //
    31  package main
    32  
    33  import (
    34  	"fmt"
    35  	"os"
    36  	"time"
    37  
    38  	"nanomsg.org/go-mangos"
    39  	"nanomsg.org/go-mangos/protocol/bus"
    40  	"nanomsg.org/go-mangos/transport/ipc"
    41  	"nanomsg.org/go-mangos/transport/tcp"
    42  )
    43  
    44  func die(format string, v ...interface{}) {
    45  	fmt.Fprintln(os.Stderr, fmt.Sprintf(format, v...))
    46  	os.Exit(1)
    47  }
    48  
    49  func node(args []string) {
    50  	var sock mangos.Socket
    51  	var err error
    52  	var msg []byte
    53  	var x int
    54  
    55  	if sock, err = bus.NewSocket(); err != nil {
    56  		die("bus.NewSocket: %s", err)
    57  	}
    58  	sock.AddTransport(ipc.NewTransport())
    59  	sock.AddTransport(tcp.NewTransport())
    60  	if err = sock.Listen(args[2]); err != nil {
    61  		die("sock.Listen: %s", err.Error())
    62  	}
    63  
    64  	// wait for everyone to start listening
    65  	time.Sleep(time.Second)
    66  	for x = 3; x < len(args); x++ {
    67  		if err = sock.Dial(args[x]); err != nil {
    68  			die("socket.Dial: %s", err.Error())
    69  		}
    70  	}
    71  
    72  	// wait for everyone to join
    73  	time.Sleep(time.Second)
    74  
    75  	fmt.Printf("%s: SENDING '%s' ONTO BUS\n", args[1], args[1])
    76  	if err = sock.Send([]byte(args[1])); err != nil {
    77  		die("sock.Send: %s", err.Error())
    78  	}
    79  	for {
    80  		if msg, err = sock.Recv(); err != nil {
    81  			die("sock.Recv: %s", err.Error())
    82  		}
    83  		fmt.Printf("%s: RECEIVED \"%s\" FROM BUS\n", args[1],
    84  			string(msg))
    85  
    86  	}
    87  }
    88  
    89  func main() {
    90  	if len(os.Args) > 3 {
    91  		node(os.Args)
    92  		os.Exit(0)
    93  	}
    94  	fmt.Fprintf(os.Stderr, "Usage: bus <NODENAME> <URL> <URL>... \n")
    95  	os.Exit(1)
    96  }