Class: Charming::Internal::EventLoop

Inherits:
Object
  • Object
show all
Defined in:
lib/charming/internal/event_loop.rb

Overview

EventLoop pumps events for a Charming runtime: it delivers the next due event — completed background tasks first, then due timers, then terminal input (with optional held-key coalescing) — to the block passed to #run, until the block returns :quit, the interrupt check trips, or a test backend runs out of events. It knows nothing about controllers, routes, or rendering; deciding what an event means belongs to its caller.

Constant Summary collapse

DEFAULT_READ_TIMEOUT = 
0.05

Instance Method Summary collapse

Constructor Details

#initialize(backend:, clock:, task_queue:, timer_bindings: [], coalesce_input: false, interrupted: -> { false }) ⇒ EventLoop

timer_bindings is the list of controller timer bindings (each responding to name and interval) to schedule. interrupted is a callable checked every iteration so a signal handler can stop the loop.



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# File 'lib/charming/internal/event_loop.rb', line 17

def initialize(backend:, clock:, task_queue:, timer_bindings: [], coalesce_input: false, interrupted: -> { false })
  @backend = backend
  @clock = clock
  @task_queue = task_queue
  @coalesce_input = coalesce_input
  @interrupted = interrupted
  @timers = build_timers(timer_bindings)
  @pending_event = nil
end

Instance Method Details

#reset_timers(timer_bindings) ⇒ Object

Replaces the scheduled timers — called when navigation lands on a controller with different timer bindings.



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# File 'lib/charming/internal/event_loop.rb', line 50

def reset_timers(timer_bindings)
  @timers = build_timers(timer_bindings)
end

#run ⇒ Object

Pumps events, yielding each to the caller together with a flag saying whether another event is already due (letting the caller coalesce a burst into one repaint). Stops when the block returns :quit, when the interrupt check returns true, or when a test backend is exhausted. Closes the task queue on the way out so producer threads can't block on a loop that is no longer draining them.



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# File 'lib/charming/internal/event_loop.rb', line 33

def run
  loop do
    break if @interrupted.call

    event = next_event
    unless event
      break if backend_exhausted?
      next
    end
    break if yield(event, more_ready?) == :quit
  end
ensure
  @task_queue.close
end

#start_timer(binding) ⇒ Object

Schedules binding one interval from now. Idempotent: starting a timer that is already running keeps its current deadline (no phase reset).



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# File 'lib/charming/internal/event_loop.rb', line 56

def start_timer(binding)
  return if timer_running?(binding.name)

  @timers << {binding: binding, next_at: clock_now + binding.interval}
end

#stop_timer(name) ⇒ Object

Removes the named timer from the schedule. Idempotent for unknown names.



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# File 'lib/charming/internal/event_loop.rb', line 63

def stop_timer(name)
  @timers.reject! { |timer| timer.fetch(:binding).name == name }
end

#timer_running?(name) ⇒ Boolean

True while the named timer is scheduled.

Returns:

  • (Boolean) 


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# File 'lib/charming/internal/event_loop.rb', line 68

def timer_running?(name)
  @timers.any? { |timer| timer.fetch(:binding).name == name }
end