nim-libp2p/libp2p/connection.nim

201 lines
6.3 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.
import oids
import chronos, chronicles, metrics
import peerinfo,
errors,
multiaddress,
stream/lpstream,
peerinfo,
varint,
vbuffer
export lpstream
logScope:
topic = "Connection"
const
DefaultReadSize* = 1 shl 20
ConnectionTrackerName* = "libp2p.connection"
type
Connection* = ref object of LPStream
peerInfo*: PeerInfo
stream*: LPStream
observedAddrs*: Multiaddress
# notice this is a ugly circular reference collection
# (we got many actually :-))
readLoops*: seq[Future[void]]
InvalidVarintException = object of LPStreamError
InvalidVarintSizeException = object of LPStreamError
ConnectionTracker* = ref object of TrackerBase
opened*: uint64
closed*: uint64
proc setupConnectionTracker(): ConnectionTracker {.gcsafe.}
proc getConnectionTracker*(): ConnectionTracker {.gcsafe.} =
result = cast[ConnectionTracker](getTracker(ConnectionTrackerName))
if isNil(result):
result = setupConnectionTracker()
proc dumpTracking(): string {.gcsafe.} =
var tracker = getConnectionTracker()
result = "Opened conns: " & $tracker.opened & "\n" &
"Closed conns: " & $tracker.closed
proc leakTransport(): bool {.gcsafe.} =
var tracker = getConnectionTracker()
result = (tracker.opened != tracker.closed)
proc setupConnectionTracker(): ConnectionTracker =
result = new ConnectionTracker
result.opened = 0
result.closed = 0
result.dump = dumpTracking
result.isLeaked = leakTransport
addTracker(ConnectionTrackerName, result)
declareGauge libp2p_open_connection, "open Connection instances"
proc newInvalidVarintException*(): ref InvalidVarintException =
newException(InvalidVarintException, "Unable to parse varint")
proc newInvalidVarintSizeException*(): ref InvalidVarintSizeException =
newException(InvalidVarintSizeException, "Wrong varint size")
proc bindStreamClose(conn: Connection) {.async.} =
# bind stream's close event to connection's close
# to ensure correct close propagation
if not isNil(conn.stream.closeEvent):
await conn.stream.closeEvent.wait()
trace "wrapped stream closed, about to close conn", closed = conn.isClosed,
peer = if not isNil(conn.peerInfo):
conn.peerInfo.id else: ""
if not conn.isClosed:
trace "wrapped stream closed, closing conn", closed = conn.isClosed,
peer = if not isNil(conn.peerInfo):
conn.peerInfo.id else: ""
await conn.close()
proc init[T: Connection](self: var T, stream: LPStream): T =
## create a new Connection for the specified async reader/writer
new self
self.stream = stream
self.closeEvent = newAsyncEvent()
when chronicles.enabledLogLevel == LogLevel.TRACE:
self.oid = genOid()
asyncCheck self.bindStreamClose()
inc getConnectionTracker().opened
libp2p_open_connection.inc()
return self
proc newConnection*(stream: LPStream): Connection =
## create a new Connection for the specified async reader/writer
result.init(stream)
method readExactly*(s: Connection,
pbytes: pointer,
nbytes: int):
Future[void] {.gcsafe.} =
s.stream.readExactly(pbytes, nbytes)
method readOnce*(s: Connection,
pbytes: pointer,
nbytes: int):
Future[int] {.gcsafe.} =
s.stream.readOnce(pbytes, nbytes)
method write*(s: Connection,
msg: seq[byte]):
Future[void] {.gcsafe.} =
s.stream.write(msg)
method closed*(s: Connection): bool =
if isNil(s.stream):
return true
result = s.stream.closed
method close*(s: Connection) {.async, gcsafe.} =
trace "about to close connection", closed = s.closed,
peer = if not isNil(s.peerInfo):
s.peerInfo.id else: ""
if not s.isClosed:
s.isClosed = true
inc getConnectionTracker().closed
if not isNil(s.stream) and not s.stream.closed:
trace "closing child stream", closed = s.closed,
peer = if not isNil(s.peerInfo):
s.peerInfo.id else: ""
await s.stream.close()
s.closeEvent.fire()
trace "waiting readloops", count=s.readLoops.len
let loopFuts = await allFinished(s.readLoops)
checkFutures(loopFuts)
s.readLoops = @[]
trace "connection closed", closed = s.closed,
peer = if not isNil(s.peerInfo):
s.peerInfo.id else: ""
libp2p_open_connection.dec()
proc readLp*(s: Connection): Future[seq[byte]] {.async, gcsafe.} =
## read lenght prefixed msg
var
size: uint
length: int
res: VarintStatus
buff = newSeq[byte](10)
try:
for i in 0..<len(buff):
await s.readExactly(addr buff[i], 1)
res = LP.getUVarint(buff.toOpenArray(0, i), length, size)
if res == VarintStatus.Success:
break
if res != VarintStatus.Success:
raise newInvalidVarintException()
if size.int > DefaultReadSize:
raise newInvalidVarintSizeException()
buff.setLen(size)
if size > 0.uint:
trace "reading exact bytes from stream", size = size
await s.readExactly(addr buff[0], int(size))
return buff
except LPStreamIncompleteError as exc:
trace "remote connection ended unexpectedly", exc = exc.msg
raise exc
except LPStreamReadError as exc:
trace "couldn't read from stream", exc = exc.msg
raise exc
proc writeLp*(s: Connection, msg: string | seq[byte]): Future[void] {.gcsafe.} =
## write lenght prefixed
var buf = initVBuffer()
buf.writeSeq(msg)
buf.finish()
s.write(buf.buffer)
method getObservedAddrs*(c: Connection): Future[MultiAddress] {.base, async, gcsafe.} =
## get resolved multiaddresses for the connection
result = c.observedAddrs
proc `$`*(conn: Connection): string =
if not isNil(conn.peerInfo):
result = $(conn.peerInfo)