rm future_combinators (#6289)

beacon_chain/future_combinators.nim

@@ -1,105 +0,0 @@
-# beacon_chain
-# Copyright (c) 2023 Status Research & Development GmbH
-# Licensed and distributed under either of
-#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
-#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
-# at your option. This file may not be copied, modified, or distributed except according to those terms.
-
-# TODO: These should be added to the Chronos's asyncfutures2 module
-#       See https://github.com/status-im/nim-chronos/pull/339
-
-import
-  chronos
-
-proc firstCompletedFuture*(futs: varargs[FutureBase]): Future[FutureBase] =
-  ## Returns a future which will complete and return completed FutureBase,
-  ## when one of the futures in ``futs`` is completed.
-  ##
-  ## If the argument is empty, the returned future FAILS immediately.
-  ##
-  ## On success, the returned Future will hold the completed FutureBase.
-  ##
-  ## If all futures fail naturally or due to cancellation, the returned
-  ## future will be failed as well.
-  ##
-  ## On cancellation, futures in ``futs`` WILL NOT BE cancelled.
-
-  var retFuture = newFuture[FutureBase]("chronos.firstCompletedFuture()")
-
-  # Because we can't capture varargs[T] in closures we need to create copy.
-  var nfuts = @futs
-
-  # If one of the Future[T] already finished we return it as result
-  for fut in nfuts:
-    if fut.completed():
-      retFuture.complete(fut)
-      return retFuture
-
-  if len(nfuts) == 0:
-    retFuture.fail(newException(ValueError, "Empty Future[T] list"))
-    return
-
-  var failedFutures = 0
-
-  var cb: proc(udata: pointer) {.gcsafe, raises: [].}
-  cb = proc(udata: pointer) {.gcsafe, raises: [].} =
-    if not(retFuture.finished()):
-      var res: FutureBase
-      var rfut = cast[FutureBase](udata)
-      if rfut.completed:
-        for i in 0..<len(nfuts):
-          if nfuts[i] != rfut:
-            nfuts[i].removeCallback(cb)
-          else:
-            res = nfuts[i]
-        retFuture.complete(res)
-      else:
-        inc failedFutures
-        if failedFutures == nfuts.len:
-          retFuture.fail(newException(CatchableError,
-            "None of the operations completed successfully"))
-
-  proc cancellation(udata: pointer) =
-    # On cancel we remove all our callbacks only.
-    for i in 0..<len(nfuts):
-      if not(nfuts[i].finished()):
-        nfuts[i].removeCallback(cb)
-
-  for fut in nfuts:
-    fut.addCallback(cb, cast[pointer](fut))
-
-  retFuture.cancelCallback = cancellation
-  return retFuture
-
-proc firstCompleted*[T](futs: varargs[Future[T]]): Future[T] =
-  ## On success, the returned Future will hold the result of the first
-  ## completed imput Future.
-  ##
-  ## If the varargs list is empty, the returned future FAILS immediately.
-  ##
-  ## If all futures fail naturally or due to cancellation, the returned
-  ## future will be failed as well.
-  ##
-  ## On cancellation, futures in ``futs`` WILL NOT BE cancelled.
-
-  let subFuture = firstCompletedFuture(futs)
-  if subFuture.completed:
-    return Future[T](subFuture.read)
-
-  var retFuture = newFuture[T]("chronos.firstCompleted()")
-
-  if subFuture.finished: # It must be failed ot cancelled
-    retFuture.fail(subFuture.error)
-    return retFuture
-
-  proc cb(udata: pointer) {.gcsafe, raises: [].} =
-    let subFuture = cast[Future[FutureBase]](udata)
-    if subFuture.completed:
-      retFuture.complete(Future[T](subFuture.read).read)
-    else:
-      retFuture.fail(subFuture.error)
-
-  subFuture.addCallback(cb, cast[pointer](subFuture))
-
-  retFuture.cancelCallback = proc (udata: pointer) =
-    subFuture.cancelSoon()