52 lines
1.3 KiB
Nim
52 lines
1.3 KiB
Nim
import std/sugar
|
|
import std/tables
|
|
import pkg/chronicles
|
|
import pkg/chronos
|
|
import ../utils/then
|
|
|
|
type
|
|
TrackedFutures* = ref object
|
|
futures: Table[uint, FutureBase]
|
|
cancelling: bool
|
|
|
|
logScope:
|
|
topics = "trackable futures"
|
|
|
|
proc len*(self: TrackedFutures): int = self.futures.len
|
|
|
|
proc removeFuture(self: TrackedFutures, future: FutureBase) =
|
|
if not self.cancelling and not future.isNil:
|
|
self.futures.del(future.id)
|
|
|
|
proc track*[T](self: TrackedFutures, fut: Future[T]): Future[T] =
|
|
if self.cancelling:
|
|
return fut
|
|
|
|
self.futures[fut.id] = FutureBase(fut)
|
|
|
|
fut
|
|
.then((val: T) => self.removeFuture(fut))
|
|
.cancelled(() => self.removeFuture(fut))
|
|
.catch((e: ref CatchableError) => self.removeFuture(fut))
|
|
|
|
return fut
|
|
|
|
proc track*[T, U](future: Future[T], self: U): Future[T] =
|
|
## Convenience method that allows chaining future, eg:
|
|
## `await someFut().track(sales)`, where `sales` has declared a
|
|
## `trackedFutures` property.
|
|
self.trackedFutures.track(future)
|
|
|
|
proc cancelTracked*(self: TrackedFutures) {.async.} =
|
|
self.cancelling = true
|
|
|
|
trace "cancelling tracked futures"
|
|
|
|
for future in self.futures.values:
|
|
if not future.isNil and not future.finished:
|
|
trace "cancelling tracked future", id = future.id
|
|
await future.cancelAndWait()
|
|
|
|
self.futures.clear()
|
|
self.cancelling = false
|