when not(compileOption("threads")): {.fatal: "Please, compile this program with the --threads:on option!".} import strformat, strutils, stew/byteutils, chronos, ../libp2p const DefaultAddr = "/ip4/127.0.0.1/tcp/0" const Help = """ Commands: /[?|help|connect|disconnect|exit] help: Prints this help connect: dials a remote peer disconnect: ends current session exit: closes the chat """ type Chat = ref object switch: Switch # a single entry point for dialing and listening to peer stdinReader: StreamTransport # transport streams between read & write file descriptor conn: Connection # connection to the other peer connected: bool # if the node is connected to another peer ## # Stdout helpers, to write the prompt ## proc writePrompt(c: Chat) = if c.connected: stdout.write '\r' & $c.switch.peerInfo.peerId & ": " stdout.flushFile() proc writeStdout(c: Chat, str: string) = echo '\r' & str c.writePrompt() ## # Chat Protocol ## const ChatCodec = "/nim-libp2p/chat/1.0.0" type ChatProto = ref object of LPProtocol proc new(T: typedesc[ChatProto], c: Chat): T = let chatproto = T() # create handler for incoming connection proc handle(stream: Connection, proto: string) {.async.} = if c.connected and not c.conn.closed: c.writeStdout "a chat session is already in progress - refusing incoming peer!" await stream.close() else: await c.handlePeer(stream) await stream.close() # assign the new handler chatproto.handler = handle chatproto.codec = ChatCodec return chatproto ## # Chat application ## proc handlePeer(c: Chat, conn: Connection) {.async.} = # Handle a peer (incoming or outgoing) try: c.conn = conn c.connected = true c.writeStdout $conn.peerId & " connected" # Read loop while true: let strData = await conn.readLp(1024) str = string.fromBytes(strData) c.writeStdout $conn.peerId & ": " & $str except LPStreamEOFError: defer: c.writeStdout $conn.peerId & " disconnected" await c.conn.close() c.connected = false proc dialPeer(c: Chat, address: string) {.async.} = # Parse and dial address let multiAddr = MultiAddress.init(address).tryGet() # split the peerId part /p2p/... peerIdBytes = multiAddr[multiCodec("p2p")] .tryGet() .protoAddress() .tryGet() remotePeer = PeerId.init(peerIdBytes).tryGet() # split the wire address ip4Addr = multiAddr[multiCodec("ip4")].tryGet() tcpAddr = multiAddr[multiCodec("tcp")].tryGet() wireAddr = ip4Addr & tcpAddr echo &"dialing peer: {multiAddr}" asyncSpawn c.handlePeer(await c.switch.dial(remotePeer, @[wireAddr], ChatCodec)) proc readLoop(c: Chat) {.async.} = while true: if not c.connected: echo "type an address or wait for a connection:" echo "type /[help|?] for help" c.writePrompt() let line = await c.stdinReader.readLine() if line.startsWith("/help") or line.startsWith("/?"): echo Help continue if line.startsWith("/disconnect"): c.writeStdout "Ending current session" if c.connected and c.conn.closed.not: await c.conn.close() c.connected = false elif line.startsWith("/connect"): c.writeStdout "enter address of remote peer" let address = await c.stdinReader.readLine() if address.len > 0: await c.dialPeer(address) elif line.startsWith("/exit"): if c.connected and c.conn.closed.not: await c.conn.close() c.connected = false await c.switch.stop() c.writeStdout "quitting..." return else: if c.connected: await c.conn.writeLp(line) else: try: if line.startsWith("/") and "p2p" in line: await c.dialPeer(line) except CatchableError as exc: echo &"unable to dial remote peer {line}" echo exc.msg proc readInput(wfd: AsyncFD) {.thread.} = ## This thread performs reading from `stdin` and sends data over ## pipe to main thread. let transp = fromPipe(wfd) while true: let line = stdin.readLine() discard waitFor transp.write(line & "\r\n") proc main() {.async.} = let rng = newRng() # Single random number source for the whole application # Pipe to read stdin from main thread (rfd, wfd) = createAsyncPipe() stdinReader = fromPipe(rfd) var thread: Thread[AsyncFD] try: thread.createThread(readInput, wfd) except Exception as exc: quit("Failed to create thread: " & exc.msg) var localAddress = MultiAddress.init(DefaultAddr).tryGet() var switch = SwitchBuilder .new() .withRng(rng) # Give the application RNG .withAddress(localAddress) .withTcpTransport() # Use TCP as transport .withMplex() # Use Mplex as muxer .withNoise() # Use Noise as secure manager .build() let chat = Chat( switch: switch, stdinReader: stdinReader) switch.mount(ChatProto.new(chat)) await switch.start() let id = $switch.peerInfo.peerId echo "PeerId: " & id echo "listening on: " for a in switch.peerInfo.addrs: echo &"{a}/p2p/{id}" await chat.readLoop() quit(0) waitFor(main())