nim-libp2p-experimental/libp2p/muxers/muxer.nim

93 lines
2.8 KiB
Nim

# Nim-LibP2P
# Copyright (c) 2022 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
# * MIT license ([LICENSE-MIT](LICENSE-MIT))
# at your option.
# This file may not be copied, modified, or distributed except according to
# those terms.
when (NimMajor, NimMinor) < (1, 4):
{.push raises: [Defect].}
else:
{.push raises: [].}
import chronos, chronicles
import ../protocols/protocol,
../stream/connection,
../errors
logScope:
topics = "libp2p muxer"
const
DefaultChanTimeout* = 5.minutes
type
MuxerError* = object of LPError
TooManyChannels* = object of MuxerError
StreamHandler* = proc(conn: Connection): Future[void] {.gcsafe, raises: [Defect].}
MuxerHandler* = proc(muxer: Muxer): Future[void] {.gcsafe, raises: [Defect].}
Muxer* = ref object of RootObj
streamHandler*: StreamHandler
connection*: Connection
# user provider proc that returns a constructed Muxer
MuxerConstructor* = proc(conn: Connection): Muxer {.gcsafe, closure, raises: [Defect].}
# this wraps a creator proc that knows how to make muxers
MuxerProvider* = ref object of LPProtocol
newMuxer*: MuxerConstructor
streamHandler*: StreamHandler # triggered every time there is a new stream, called for any muxer instance
muxerHandler*: MuxerHandler # triggered every time there is a new muxed connection created
func shortLog*(m: Muxer): auto = shortLog(m.connection)
chronicles.formatIt(Muxer): shortLog(it)
# muxer interface
method newStream*(m: Muxer, name: string = "", lazy: bool = false):
Future[Connection] {.base, async, gcsafe.} = discard
method close*(m: Muxer) {.base, async, gcsafe.} = discard
method handle*(m: Muxer): Future[void] {.base, async, gcsafe.} = discard
proc new*(
T: typedesc[MuxerProvider],
creator: MuxerConstructor,
codec: string): T {.gcsafe.} =
let muxerProvider = T(newMuxer: creator)
muxerProvider.codec = codec
muxerProvider.init()
muxerProvider
method init(c: MuxerProvider) =
proc handler(conn: Connection, proto: string) {.async, gcsafe, closure.} =
trace "starting muxer handler", proto=proto, conn
try:
let
muxer = c.newMuxer(conn)
if not isNil(c.streamHandler):
muxer.streamHandler = c.streamHandler
var futs = newSeq[Future[void]]()
futs &= muxer.handle()
# finally await both the futures
if not isNil(c.muxerHandler):
await c.muxerHandler(muxer)
when defined(libp2p_agents_metrics):
conn.shortAgent = muxer.connection.shortAgent
checkFutures(await allFinished(futs))
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "exception in muxer handler", exc = exc.msg, conn, proto
finally:
await conn.close()
c.handler = handler