nim-libp2p-experimental/libp2p/stream/chronosstream.nim

87 lines
2.4 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.
import chronos, chronicles
import lpstream, ../utility
logScope:
topic = "ChronosStream"
type ChronosStream* = ref object of LPStream
client: StreamTransport
proc newChronosStream*(client: StreamTransport): ChronosStream =
new result
result.client = client
result.closeEvent = newAsyncEvent()
template withExceptions(body: untyped) =
try:
body
except TransportIncompleteError:
raise newLPStreamIncompleteError()
except TransportLimitError:
raise newLPStreamLimitError()
except TransportUseClosedError:
raise newLPStreamEOFError()
except TransportError:
# TODO https://github.com/status-im/nim-chronos/pull/99
raise newLPStreamEOFError()
# raise (ref LPStreamError)(msg: exc.msg, parent: exc)
method readExactly*(s: ChronosStream,
pbytes: pointer,
nbytes: int): Future[void] {.async.} =
if s.atEof:
raise newLPStreamEOFError()
withExceptions:
await s.client.readExactly(pbytes, nbytes)
method readOnce*(s: ChronosStream, pbytes: pointer, nbytes: int): Future[int] {.async.} =
if s.atEof:
raise newLPStreamEOFError()
withExceptions:
result = await s.client.readOnce(pbytes, nbytes)
method write*(s: ChronosStream, msg: seq[byte]) {.async.} =
if s.closed:
raise newLPStreamClosedError()
if msg.len == 0:
return
withExceptions:
# Returns 0 sometimes when write fails - but there's not much we can do here?
if (await s.client.write(msg)) != msg.len:
raise (ref LPStreamError)(msg: "Write couldn't finish writing")
method closed*(s: ChronosStream): bool {.inline.} =
result = s.client.closed
method atEof*(s: ChronosStream): bool {.inline.} =
s.client.atEof()
method close*(s: ChronosStream) {.async.} =
if not s.isClosed:
s.isClosed = true
trace "shutting chronos stream", address = $s.client.remoteAddress()
if not s.client.closed():
try:
await s.client.closeWait()
except CancelledError as exc:
raise exc
except CatchableError as exc:
# Shouldn't happen, but we can't be sure
warn "error while closing connection", msg = exc.msg
s.closeEvent.fire()