mirror of
https://github.com/status-im/nim-dagger.git
synced 2025-02-25 12:55:34 +00:00
87590f43ce
* fix(statemachine): do not raise from state.run * fix rebase * fix exception handling in SaleProvingSimulated.prove - re-raise CancelledError - don't return State on CatchableError - expect the Proofs_InvalidProof custom error instead of checking a string * asyncSpawn salesagent.onCancelled This was swallowing a KeyError in one of the tests (fixed in the previous commit) * remove error handling states in asyncstatemachine * revert unneeded changes * formatting * PR feedback, logging updates
104 lines
2.7 KiB
Nim
104 lines
2.7 KiB
Nim
import pkg/questionable
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import pkg/chronos
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import ../logutils
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import ./trackedfutures
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import ./exceptions
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{.push raises: [].}
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type
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Machine* = ref object of RootObj
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state: State
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running: Future[void]
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scheduled: AsyncQueue[Event]
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started: bool
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trackedFutures: TrackedFutures
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State* = ref object of RootObj
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Query*[T] = proc(state: State): T
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Event* = proc(state: State): ?State {.gcsafe, raises: [].}
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logScope:
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topics = "statemachine"
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proc new*[T: Machine](_: type T): T =
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T(trackedFutures: TrackedFutures.new())
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method `$`*(state: State): string {.base, gcsafe.} =
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raiseAssert "not implemented"
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proc transition(_: type Event, previous, next: State): Event =
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return proc(state: State): ?State =
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if state == previous:
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return some next
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proc query*[T](machine: Machine, query: Query[T]): ?T =
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if machine.state.isNil:
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none T
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else:
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some query(machine.state)
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proc schedule*(machine: Machine, event: Event) =
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if not machine.started:
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return
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try:
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machine.scheduled.putNoWait(event)
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except AsyncQueueFullError:
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raiseAssert "unlimited queue is full?!"
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method run*(
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state: State, machine: Machine
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): Future[?State] {.base, async: (raises: []).} =
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discard
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proc run(machine: Machine, state: State) {.async: (raises: []).} =
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if next =? await state.run(machine):
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machine.schedule(Event.transition(state, next))
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proc scheduler(machine: Machine) {.async: (raises: []).} =
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var running: Future[void].Raising([])
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while machine.started:
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try:
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let event = await machine.scheduled.get()
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if next =? event(machine.state):
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if not running.isNil and not running.finished:
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trace "cancelling current state", state = $machine.state
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await running.cancelAndWait()
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let fromState =
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if machine.state.isNil:
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"<none>"
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else:
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$machine.state
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machine.state = next
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debug "enter state", state = fromState & " => " & $machine.state
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running = machine.run(machine.state)
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machine.trackedFutures.track(running)
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asyncSpawn running
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except CancelledError:
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break # do not propagate bc it is asyncSpawned
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proc start*(machine: Machine, initialState: State) =
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if machine.started:
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return
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if machine.scheduled.isNil:
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machine.scheduled = newAsyncQueue[Event]()
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machine.started = true
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let fut = machine.scheduler()
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machine.trackedFutures.track(fut)
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asyncSpawn fut
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machine.schedule(Event.transition(machine.state, initialState))
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proc stop*(machine: Machine) {.async.} =
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if not machine.started:
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return
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trace "stopping state machine"
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machine.started = false
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await machine.trackedFutures.cancelTracked()
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machine.state = nil
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