py-libp2p/tests_interop/go_pkgs/examples/echo/main.go
2020-02-28 15:50:01 +08:00

139 lines
3.4 KiB
Go

package main
import (
"bufio"
"context"
"flag"
"fmt"
"io/ioutil"
"log"
utils "interop/utils"
"github.com/libp2p/go-libp2p-core/network"
"github.com/libp2p/go-libp2p-core/peer"
"github.com/libp2p/go-libp2p-core/peerstore"
golog "github.com/ipfs/go-log"
ma "github.com/multiformats/go-multiaddr"
gologging "github.com/whyrusleeping/go-logging"
)
func main() {
// LibP2P code uses golog to log messages. They log with different
// string IDs (i.e. "swarm"). We can control the verbosity level for
// all loggers with:
golog.SetAllLoggers(gologging.DEBUG) // Change to DEBUG for extra info
// Parse options from the command line
listenF := flag.Int("l", 0, "wait for incoming connections")
target := flag.String("d", "", "target peer to dial")
protocolID := flag.String("security", "", "security protocol used for secure channel")
seed := flag.Int64("seed", 0, "set random seed for id generation")
flag.Parse()
if *listenF == 0 {
log.Fatal("Please provide a port to bind on with -l")
}
// Make a host that listens on the given multiaddress
ha, err := utils.MakeBasicHost(*listenF, *protocolID, *seed)
if err != nil {
log.Fatal(err)
}
// Set a stream handler on host A. /echo/1.0.0 is
// a user-defined protocol name.
ha.SetStreamHandler("/echo/1.0.0", func(s network.Stream) {
log.Println("Got a new stream!")
if err := doEcho(s); err != nil {
log.Println(err)
s.Reset()
} else {
s.Close()
}
})
if *target == "" {
log.Println("listening for connections")
select {} // hang forever
}
/**** This is where the listener code ends ****/
// The following code extracts target's the peer ID from the
// given multiaddress
ipfsaddr, err := ma.NewMultiaddr(*target)
if err != nil {
log.Fatalln(err)
}
pid, err := ipfsaddr.ValueForProtocol(ma.P_IPFS)
if err != nil {
log.Fatalln(err)
}
peerid, err := peer.IDB58Decode(pid)
if err != nil {
log.Fatalln(err)
}
// Decapsulate the /ipfs/<peerID> part from the target
// /ip4/<a.b.c.d>/ipfs/<peer> becomes /ip4/<a.b.c.d>
targetPeerAddr, _ := ma.NewMultiaddr(
fmt.Sprintf("/ipfs/%s", peer.IDB58Encode(peerid)))
targetAddr := ipfsaddr.Decapsulate(targetPeerAddr)
log.Println("!@# targetAddr=", targetAddr)
// We have a peer ID and a targetAddr so we add it to the peerstore
// so LibP2P knows how to contact it
ha.Peerstore().AddAddr(peerid, targetAddr, peerstore.PermanentAddrTTL)
log.Println("!@# ipfsaddr=", ipfsaddr)
pinfo, err := peer.AddrInfoFromP2pAddr(ipfsaddr)
if err != nil {
log.Fatalf("failed to parse %v to pinfo\n", ipfsaddr)
}
err = ha.Connect(context.Background(), *pinfo)
if err != nil {
panic(err)
}
log.Println("connect with peer", *pinfo)
// make a new stream from host B to host A
// it should be handled on host A by the handler we set above because
// we use the same /echo/1.0.0 protocol
s, err := ha.NewStream(context.Background(), peerid, "/echo/1.0.0")
if err != nil {
log.Fatalln(err)
}
log.Println("opened stream")
_, err = s.Write([]byte("Hello, world!\n"))
if err != nil {
log.Fatalln(err)
}
out, err := ioutil.ReadAll(s)
if err != nil {
log.Fatalln(err)
}
log.Printf("read reply: %q\n", out)
}
// doEcho reads a line of data a stream and writes it back
func doEcho(s network.Stream) error {
buf := bufio.NewReader(s)
str, err := buf.ReadString('\n')
if err != nil {
return err
}
log.Printf("read: %s\n", str)
_, err = s.Write([]byte(str))
return err
}