Class: Dommy::Scheduler

Inherits:
Object
  • Object
show all
Defined in:
lib/dommy/scheduler.rb

Overview

Deterministic host-side scheduler for timers, rAF, and microtasks. Time advances only when the host explicitly calls ‘advance_time`.

Defined Under Namespace

Classes: Timer

Constant Summary collapse

FRAME_MS = 
16

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Scheduler

Returns a new instance of Scheduler.



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# File 'lib/dommy/scheduler.rb', line 11

def initialize
  @now_ms = 0
  @next_id = 1
  @timers = {}
  @microtasks = []
end

Instance Attribute Details

#now_ms ⇒ Object (readonly)

Returns the value of attribute now_ms.



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# File 'lib/dommy/scheduler.rb', line 18

def now_ms
  @now_ms
end

Instance Method Details

#advance_time(delta_ms) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 62

def advance_time(delta_ms)
  target = @now_ms + [delta_ms.to_i, 0].max
  while next_due_timer_at && next_due_timer_at <= target
    @now_ms = next_due_timer_at
    run_due_timers
    drain_microtasks
  end

  @now_ms = target
  drain_microtasks
  nil
end

#cancel_animation_frame(id) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 44

def cancel_animation_frame(id)
  cancel_timer(id)
end

#clear_interval(id) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 33

def clear_interval(id)
  cancel_timer(id)
end

#clear_timeout(id) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 24

def clear_timeout(id)
  cancel_timer(id)
end

#drain_microtasks ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 53

def drain_microtasks
  until @microtasks.empty?
    callback = @microtasks.shift
    invoke_callback(callback, [@now_ms])
  end

  nil
end

#drain_timers(advance: 0) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 75

def drain_timers(advance: 0)
  advance_time(advance)
end

#next_due_timer_at ⇒ Object

Public accessor for eval-time auto-drain: keep advancing the clock until no timers remain (or a safety budget runs out).



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# File 'lib/dommy/scheduler.rb', line 81

def next_due_timer_at
  @timers.values.select(&:active).map(&:due_at).min
end

#queue_microtask(callback) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 48

def queue_microtask(callback)
  @microtasks << callback
  nil
end

#request_animation_frame(callback) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 37

def request_animation_frame(callback)
  frames = ((@now_ms / FRAME_MS) + 1) * FRAME_MS
  id = next_id
  @timers[id] = Timer.new(id, :raf, callback, frames, nil, true)
  id
end

#set_interval(callback, interval_ms) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 28

def set_interval(callback, interval_ms)
  ms = [interval_ms.to_i, 0].max
  register_timer(:interval, callback, ms, ms)
end

#set_timeout(callback, delay_ms) ⇒ Object 



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# File 'lib/dommy/scheduler.rb', line 20

def set_timeout(callback, delay_ms)
  register_timer(:timeout, callback, delay_ms.to_i, nil)
end