nim-libp2p/docs/tutorial/directchat/second.nim

150 lines
4.7 KiB
Nim

when not(compileOption("threads")):
{.fatal: "Please, compile this program with the --threads:on option!".}
import tables, strformat, strutils
import chronos
import ../libp2p/[switch,
multistream,
crypto/crypto,
protocols/identify,
connection,
transports/transport,
transports/tcptransport,
multiaddress,
peerinfo,
peerid,
protocols/protocol,
protocols/secure/secure,
protocols/secure/secio,
muxers/muxer,
muxers/mplex/mplex]
const ChatCodec = "/nim-libp2p/chat/1.0.0"
const DefaultAddr = "/ip4/127.0.0.1/tcp/55505"
const Help = """
Commands: /[?|hep|connect|disconnect|exit]
help: Prints this help
connect: dials a remote peer
disconnect: ends current session
exit: closes the chat
"""
type ChatProto = ref object of LPProtocol
switch: Switch # a single entry point for dialing and listening to peer
transp: StreamTransport # transport streams between read & write file descriptor
conn: Connection # create and close read & write stream
connected: bool # if the node is connected to another peer
started: bool # if the node has started
# copied from https://github.com/status-im/nim-beacon-chain/blob/0ed657e953740a92458f23033d47483ffa17ccb0/beacon_chain/eth2_network.nim#L109-L115
proc initAddress(T: type MultiAddress, str: string): T =
let address = MultiAddress.init(str)
if IPFS.match(address) and matchPartial(multiaddress.TCP, address):
result = address
else:
raise newException(MultiAddressError,
"Invalid bootstrap node multi-address")
proc dialPeer(p: ChatProto, address: string) {.async.} =
let multiAddr = MultiAddress.initAddress(address);
let parts = address.split("/")
let remotePeer = PeerInfo.init(parts[^1],
[multiAddr])
echo &"dialing peer: {multiAddr}"
p.conn = await p.switch.dial(remotePeer, ChatCodec)
p.connected = true
proc readAndPrint(p: ChatProto) {.async.} =
while true:
while p.connected:
echo cast[string](await p.conn.readLp(1024))
await sleepAsync(100.millis)
proc writeAndPrint(p: ChatProto) {.async.} =
while true:
if not p.connected:
echo "type an address or wait for a connection:"
echo "type /[help|?] for help"
let line = await p.transp.readLine()
if line.startsWith("/help") or line.startsWith("/?") or not p.started:
echo Help
continue
if line.startsWith("/disconnect"):
echo "Ending current session"
if p.connected and p.conn.closed.not:
await p.conn.close()
p.connected = false
elif line.startsWith("/connect"):
if p.connected:
var yesno = "N"
echo "a session is already in progress, do you want end it [y/N]?"
yesno = await p.transp.readLine()
if yesno.cmpIgnoreCase("y") == 0:
await p.conn.close()
p.connected = false
elif yesno.cmpIgnoreCase("n") == 0:
continue
else:
echo "unrecognized response"
continue
echo "enter address of remote peer"
let address = await p.transp.readLine()
if address.len > 0:
await p.dialPeer(address)
elif line.startsWith("/exit"):
if p.connected and p.conn.closed.not:
await p.conn.close()
p.connected = false
await p.switch.stop()
echo "quitting..."
quit(0)
else:
if p.connected:
await p.conn.writeLp(line)
else:
try:
if line.startsWith("/") and "ipfs" in line:
await p.dialPeer(line)
except:
echo &"unable to dial remote peer {line}"
echo getCurrentExceptionMsg()
proc readWriteLoop(p: ChatProto) {.async.} =
asyncCheck p.writeAndPrint() # execute the async function but does not block
asyncCheck p.readAndPrint()
proc processInput(rfd: AsyncFD) {.async.} =
let transp = fromPipe(rfd)
while true:
let a = await transp.readLine()
echo "You just entered: " & a
proc readInput(wfd: AsyncFD) {.thread.} =
## This procedure 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 (rfd, wfd) = createAsyncPipe()
if rfd == asyncInvalidPipe or wfd == asyncInvalidPipe:
raise newException(ValueError, "Could not initialize pipe!")
var thread: Thread[AsyncFD]
thread.createThread(readInput, wfd)
await processInput(rfd)
when isMainModule: # isMainModule = true when the module is compiled as the main file
waitFor(main())