nim-libp2p/libp2p/muxers/mplex/mplex.nim

123 lines
4.4 KiB
Nim

## Nim-LibP2P
## Copyright (c) 2019 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.
## TODO:
## Timeouts and message limits are still missing
## they need to be added ASAP
import tables, sequtils, options, strformat
import chronos, chronicles
import coder, types, lpchannel,
../muxer,
../../varint,
../../connection,
../../vbuffer,
../../protocols/protocol,
../../stream/bufferstream,
../../stream/lpstream
logScope:
topic = "Mplex"
type
Mplex* = ref object of Muxer
remote*: Table[uint, LPChannel]
local*: Table[uint, LPChannel]
currentId*: uint
maxChannels*: uint
proc newMplexUnknownMsgError(): ref MplexUnknownMsgError =
result = newException(MplexUnknownMsgError, "Unknown mplex message type")
proc getChannelList(m: Mplex, initiator: bool): var Table[uint, LPChannel] =
if initiator:
result = m.remote
else:
result = m.local
proc newStreamInternal*(m: Mplex,
initiator: bool = true,
chanId: uint = 0,
name: string = ""):
Future[LPChannel] {.async, gcsafe.} =
## create new channel/stream
let id = if initiator: m.currentId.inc(); m.currentId else: chanId
result = newChannel(id, m.connection, initiator, name)
m.getChannelList(initiator)[id] = result
method handle*(m: Mplex) {.async, gcsafe.} =
trace "starting mplex main loop"
try:
while not m.connection.closed:
let (id, msgType, data) = (await m.connection.readMsg()).get()
let initiator = bool(ord(msgType) and 1)
var channel: LPChannel
if MessageType(msgType) != MessageType.New:
let channels = m.getChannelList(initiator)
if not channels.contains(id):
trace "handle: Channel with id and msg type ", id = id, msg = msgType
continue
channel = channels[id]
case msgType:
of MessageType.New:
let name = cast[string](data)
channel = await m.newStreamInternal(false, id, name)
trace "handle: created channel ", id = id, name = name
if not isNil(m.streamHandler):
let stream = newConnection(channel)
stream.peerInfo = m.connection.peerInfo
let handlerFut = m.streamHandler(stream)
# channel cleanup routine
proc cleanUpChan(udata: pointer) {.gcsafe.} =
if handlerFut.finished:
channel.close().addCallback(
proc(udata: pointer) =
channel.cleanUp()
.addCallback(proc(udata: pointer) =
trace "handle: cleaned up channel ", id = id))
handlerFut.addCallback(cleanUpChan)
continue
of MessageType.MsgIn, MessageType.MsgOut:
trace "handle: pushing data to channel ", id = id, msgType = msgType
await channel.pushTo(data)
of MessageType.CloseIn, MessageType.CloseOut:
trace "handle: closing channel ", id = id, msgType = msgType
await channel.closedByRemote()
m.getChannelList(initiator).del(id)
of MessageType.ResetIn, MessageType.ResetOut:
trace "handle: resetting channel ", id = id
await channel.resetByRemote()
break
else: raise newMplexUnknownMsgError()
except:
error "exception occurred", exception = getCurrentExceptionMsg()
finally:
await m.connection.close()
proc newMplex*(conn: Connection,
maxChanns: uint = MaxChannels): Mplex =
new result
result.connection = conn
result.maxChannels = maxChanns
result.remote = initTable[uint, LPChannel]()
result.local = initTable[uint, LPChannel]()
method newStream*(m: Mplex, name: string = ""): Future[Connection] {.async, gcsafe.} =
let channel = await m.newStreamInternal()
await m.connection.writeMsg(channel.id, MessageType.New, name)
result = newConnection(channel)
result.peerInfo = m.connection.peerInfo
method close*(m: Mplex) {.async, gcsafe.} =
await allFutures(@[allFutures(toSeq(m.remote.values).mapIt(it.close())),
allFutures(toSeq(m.local.values).mapIt(it.close()))])
m.connection.reset()