class ElasticAPM::Metrics::VM

def collect
  return if disabled?
  stat = GC.stat
  thread_count = Thread.list.count
  sample = {
    'ruby.gc.count': stat[:count],
    'ruby.threads': thread_count
  }
  (live_slots = stat[:heap_live_slots]) &&
    sample[:'ruby.heap.slots.live'] = live_slots
  (heap_slots = stat[:heap_free_slots]) &&
    sample[:'ruby.heap.slots.free'] = heap_slots
  (allocated = stat[:total_allocated_objects]) &&
    sample[:'ruby.heap.allocations.total'] = allocated
  return sample unless GC::Profiler.enabled?
  @total_time += GC::Profiler.total_time
  GC::Profiler.clear
  sample[:'ruby.gc.time'] = @total_time
  sample
rescue TypeError => e
  error 'VM metrics encountered error: %s', e
  debug('Backtrace:') { e.backtrace.join("\n") }
  @disabled = true
  nil
end

def disabled?
  @disabled
end

def initialize(config)
  @config = config
  @total_time = 0
  @disabled = false
end