ceremonyclient/go-libp2p/examples/ipfs-camp-2019/06-Pubsub/protocol.go

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2023-08-21 03:50:38 +00:00
package main
import (
"bufio"
"context"
"fmt"
"io"
"os"
"github.com/libp2p/go-libp2p/core/host"
"github.com/libp2p/go-libp2p/core/network"
)
const chatProtocol = "/libp2p/chat/1.0.0"
// TODO: Replace this handler with a function that handles message from a
// pubsub Subscribe channel.
func chatHandler(s network.Stream) {
data, err := io.ReadAll(s)
if err != nil {
fmt.Fprintln(os.Stderr, err)
}
fmt.Println("Received:", string(data))
}
// TODO: Replace this with a send function that publishes the string messages
// on our pubsub topic.
func chatSend(msg string, s network.Stream) error {
fmt.Println("Sending:", msg)
w := bufio.NewWriter(s)
n, err := w.WriteString(msg)
if n != len(msg) {
return fmt.Errorf("expected to write %d bytes, wrote %d", len(msg), n)
}
if err != nil {
return err
}
if err = w.Flush(); err != nil {
return err
}
s.Close()
data, err := io.ReadAll(s)
if err != nil {
return err
}
if len(data) > 0 {
fmt.Println("Received:", string(data))
}
return nil
}
func chatInputLoop(ctx context.Context, h host.Host, donec chan struct{}) {
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
msg := scanner.Text()
for _, peer := range h.Network().Peers() {
if _, err := h.Peerstore().SupportsProtocols(peer, chatProtocol); err == nil {
s, err := h.NewStream(ctx, peer, chatProtocol)
defer func() {
if err != nil {
fmt.Fprintln(os.Stderr, err)
}
}()
if err != nil {
continue
}
err = chatSend(msg, s)
}
}
}
donec <- struct{}{}
}