nim-libp2p/libp2p/utils/future.nim

51 lines
1.5 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.
{.push raises: [].}
import sequtils
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)
proc raceAndCancelPending*(
futs: seq[SomeFuture]
): Future[void] {.async: (raises: [ValueError, CancelledError]).} =
## Executes a race between the provided sequence of futures.
## Cancels any remaining futures that have not yet completed.
##
## - `futs`: A sequence of futures to race.
##
## Raises:
## - `ValueError` if the sequence of futures is empty.
## - `CancelledError` if the operation is canceled.
try:
discard await race(futs)
finally:
await noCancel allFutures(futs.filterIt(not it.finished).mapIt(it.cancelAndWait))