class Appsignal::Probes::MriProbe

def self.dependencies_present?
  defined?(::RubyVM) && ::RubyVM.respond_to?(:stat)
end

def call
  stat = RubyVM.stat
  constant_cache_invalidations = stat[:constant_cache_invalidations]
  if constant_cache_invalidations
    set_gauge_with_hostname(
      "ruby_vm",
      constant_cache_invalidations,
      :metric => :constant_cache_invalidations
    )
  end
  constant_cache_misses = stat[:constant_cache_misses]
  if constant_cache_misses
    set_gauge_with_hostname(
      "ruby_vm",
      constant_cache_misses,
      :metric => :constant_cache_misses
    )
  end
  class_serial = stat[:class_serial]
  set_gauge_with_hostname("ruby_vm", class_serial, :metric => :class_serial) if class_serial
  global_constant_state =
    stat[:constant_cache] ? stat[:constant_cache].values.sum : stat[:global_constant_state]
  if global_constant_state
    set_gauge_with_hostname(
      "ruby_vm",
      global_constant_state,
      :metric => :global_constant_state
    )
  end
  set_gauge_with_hostname("thread_count", Thread.list.size)
  if Appsignal::GarbageCollection.enabled?
    gauge_delta(:gc_time, @gc_profiler.total_time) do |gc_time|
      set_gauge_with_hostname("gc_time", gc_time) if gc_time > 0
    end
  end
  gc_stats = GC.stat
  gauge_delta(
    :allocated_objects,
    gc_stats[:total_allocated_objects] || gc_stats[:total_allocated_object]
  ) do |allocated_objects|
    set_gauge_with_hostname("allocated_objects", allocated_objects)
  end
  gauge_delta(:gc_count, GC.count) do |gc_count|
    set_gauge_with_hostname("gc_count", gc_count, :metric => :gc_count)
  end
  gauge_delta(:minor_gc_count, gc_stats[:minor_gc_count]) do |minor_gc_count|
    set_gauge_with_hostname("gc_count", minor_gc_count, :metric => :minor_gc_count)
  end
  gauge_delta(:major_gc_count, gc_stats[:major_gc_count]) do |major_gc_count|
    set_gauge_with_hostname("gc_count", major_gc_count, :metric => :major_gc_count)
  end
  set_gauge_with_hostname("heap_slots",
    gc_stats[:heap_live_slots] || gc_stats[:heap_live_slot], :metric => :heap_live)
  set_gauge_with_hostname("heap_slots",
    gc_stats[:heap_free_slots] || gc_stats[:heap_free_slot], :metric => :heap_free)
end

def initialize(appsignal: Appsignal, gc_profiler: Appsignal::GarbageCollection.profiler)
  Appsignal.internal_logger.debug("Initializing VM probe")
  @appsignal = appsignal
  @gc_profiler = gc_profiler
end