logos-storage-nim/codex/utils/asyncstatemachine.nim
Dmitriy Ryajov 1cac3e2a11
Fix/rework async exceptions (#1130)
* cleanup imports and logs

* add BlockHandle type

* revert deps

* refactor: async error handling and future tracking improvements

- Update async procedures to use explicit raises annotation
- Modify TrackedFutures to handle futures with no raised exceptions
- Replace `asyncSpawn` with explicit future tracking
- Update test suites to use `unittest2`
- Standardize error handling across network and async components
- Remove deprecated error handling patterns

This commit introduces a more robust approach to async error handling and future management, improving type safety and reducing potential runtime errors.

* bump nim-serde

* remove asyncSpawn

* rework background downloads and prefetch

* imporove logging

* refactor: enhance async procedures with error handling and raise annotations

* misc cleanup

* misc

* refactor: implement allFinishedFailed to aggregate future results with success and failure tracking

* refactor: update error handling in reader procedures to raise ChunkerError and CancelledError

* refactor: improve error handling in wantListHandler and accountHandler procedures

* refactor: simplify LPStreamReadError creation by consolidating parameters

* refactor: enhance error handling in AsyncStreamWrapper to catch unexpected errors

* refactor: enhance error handling in advertiser and discovery loops to improve resilience

* misc

* refactor: improve code structure and readability

* remove cancellation from addSlotToQueue

* refactor: add assertion for unexpected errors in local store checks

* refactor: prevent tracking of finished futures and improve test assertions

* refactor: improve error handling in local store checks

* remove usage of msgDetail

* feat: add initial implementation of discovery engine and related components

* refactor: improve task scheduling logic by removing unnecessary break statement

* break after scheduling a task

* make taskHandler cancelable

* refactor: update async handlers to raise CancelledError

* refactor(advertiser): streamline error handling and improve task flow in advertise loops

* fix: correct spelling of "divisible" in error messages and comments

* refactor(discovery): simplify discovery task loop and improve error handling

* refactor(engine): filter peers before processing in cancelBlocks procedure
2025-03-13 07:33:15 -07:00

102 lines
2.6 KiB
Nim

import pkg/questionable
import pkg/chronos
import ../logutils
import ./trackedfutures
import ./exceptions
{.push raises: [].}
type
Machine* = ref object of RootObj
state: State
running: Future[void]
scheduled: AsyncQueue[Event]
started: bool
trackedFutures: TrackedFutures
State* = ref object of RootObj
Query*[T] = proc(state: State): T
Event* = proc(state: State): ?State {.gcsafe, raises: [].}
logScope:
topics = "statemachine"
proc new*[T: Machine](_: type T): T =
T(trackedFutures: TrackedFutures.new())
method `$`*(state: State): string {.base, gcsafe.} =
raiseAssert "not implemented"
proc transition(_: type Event, previous, next: State): Event =
return proc(state: State): ?State =
if state == previous:
return some next
proc query*[T](machine: Machine, query: Query[T]): ?T =
if machine.state.isNil:
none T
else:
some query(machine.state)
proc schedule*(machine: Machine, event: Event) =
if not machine.started:
return
try:
machine.scheduled.putNoWait(event)
except AsyncQueueFullError:
raiseAssert "unlimited queue is full?!"
method run*(
state: State, machine: Machine
): Future[?State] {.base, async: (raises: []).} =
discard
proc run(machine: Machine, state: State) {.async: (raises: []).} =
if next =? await state.run(machine):
machine.schedule(Event.transition(state, next))
proc scheduler(machine: Machine) {.async: (raises: []).} =
var running: Future[void].Raising([])
while machine.started:
try:
let event = await machine.scheduled.get()
if next =? event(machine.state):
if not running.isNil and not running.finished:
trace "cancelling current state", state = $machine.state
await running.cancelAndWait()
let fromState =
if machine.state.isNil:
"<none>"
else:
$machine.state
machine.state = next
debug "enter state", state = fromState & " => " & $machine.state
running = machine.run(machine.state)
machine.trackedFutures.track(running)
except CancelledError:
break # do not propagate bc it is asyncSpawned
proc start*(machine: Machine, initialState: State) =
if machine.started:
return
if machine.scheduled.isNil:
machine.scheduled = newAsyncQueue[Event]()
machine.started = true
let fut = machine.scheduler()
machine.trackedFutures.track(fut)
machine.schedule(Event.transition(machine.state, initialState))
proc stop*(machine: Machine) {.async.} =
if not machine.started:
return
trace "stopping state machine"
machine.started = false
await machine.trackedFutures.cancelTracked()
machine.state = nil