nim-libp2p-experimental/libp2p/utils/future.nim

36 lines
1.0 KiB
Nim

# Nim-Libp2p
# Copyright (c) 2023 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
type
AllFuturesFailedError* = object of CatchableError
proc anyCompleted*[T](futs: seq[Future[T]]): Future[Future[T]] {.async.} =
## Returns a future that will complete with the first future that completes.
## If all futures fail or futs is empty, the returned future will fail with AllFuturesFailedError.
var requests = futs
while true:
if requests.len == 0:
raise newException(AllFuturesFailedError, "None of the futures completed successfully")
var raceFut = await one(requests)
if raceFut.completed:
return raceFut
let index = requests.find(raceFut)
requests.del(index)