Class: DeadBro::ViewRenderingSubscriber

Inherits:
Object
  • Object
show all
Defined in:
lib/dead_bro/view_rendering_subscriber.rb

Constant Summary collapse

RENDER_TEMPLATE_EVENT = 
"render_template.action_view"
RENDER_PARTIAL_EVENT = 
"render_partial.action_view"
RENDER_COLLECTION_EVENT = 
"render_collection.action_view"
THREAD_LOCAL_KEY = 
:dead_bro_view_events
THREAD_LOCAL_AGGREGATES_KEY = 
:dead_bro_view_aggregates
MAX_TRACKED_EVENTS = 
500

Class Method Summary collapse

Class Method Details

.add_view_event(view_info) ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 51

def self.add_view_event(view_info)
  return unless Thread.current[THREAD_LOCAL_KEY]
  aggregates = Thread.current[THREAD_LOCAL_AGGREGATES_KEY]
  return unless aggregates

  key = view_info[:identifier].to_s
  dur = view_info[:duration_ms].to_f
  rendered_at = view_info[:rendered_at]

  if (agg = aggregates[key])
    agg[:count]                   += 1
    agg[:total_duration_ms]        = (agg[:total_duration_ms] + dur).round(2)
    agg[:max_duration_ms]          = [agg[:max_duration_ms], dur].max
    agg[:min_duration_ms]          = [agg[:min_duration_ms], dur].min
    agg[:rendered_at_min]          = [agg[:rendered_at_min], rendered_at].compact.min if rendered_at
    agg[:rendered_at_max]          = [agg[:rendered_at_max], rendered_at].compact.max if rendered_at
    agg[:cache_hit_count]         += 1 if view_info[:cache_key]
    agg[:collection_count]        += view_info[:collection_count].to_i
    agg[:collection_cached_count] += view_info[:collection_cached_count].to_i
  else
    return if aggregates.size >= MAX_TRACKED_EVENTS
    aggregates[key] = {
      identifier:              key,
      type:                    view_info[:type],
      count:                   1,
      total_duration_ms:       dur,
      max_duration_ms:         dur,
      min_duration_ms:         dur,
      rendered_at_min:         rendered_at,
      rendered_at_max:         rendered_at,
      cache_hit_count:         (view_info[:cache_key] ? 1 : 0),
      collection_count:        view_info[:collection_count].to_i,
      collection_cached_count: view_info[:collection_cached_count].to_i
    }
  end
end

.analyze_view_performance(view_events) ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 95

def self.analyze_view_performance(view_events)
  return {} if view_events.empty?

  total_renders  = view_events.sum { |e| e_int(e, :count, 1) }
  total_duration = view_events.sum { |e| e_flt(e, :total_duration_ms) }

  by_type = Hash.new(0)
  view_events.each { |e| by_type[e_str(e, :type)] += e_int(e, :count, 1) }

  slowest = view_events.sort_by { |e| -e_flt(e, :max_duration_ms) }.first(5).map do |e|
    { identifier: e_str(e, :identifier), duration_ms: e_flt(e, :max_duration_ms), type: e_str(e, :type) }
  end

  most_frequent = view_events.sort_by { |e| -e_int(e, :count, 1) }.first(5).map do |e|
    { identifier: e_str(e, :identifier), count: e_int(e, :count, 1) }
  end

  partials                = view_events.select { |e| e_str(e, :type) == "partial" }
  total_partial_renders   = partials.sum { |e| e_int(e, :count, 1) }
  total_cache_hits        = partials.sum { |e| e_int(e, :cache_hit_count) }
  partial_cache_hit_rate  = total_partial_renders > 0 ? (total_cache_hits.to_f / total_partial_renders * 100).round(2) : 0

  collections            = view_events.select { |e| e_str(e, :type) == "collection" }
  total_collection_items = collections.sum { |e| e_int(e, :collection_count) }
  total_cached_items     = collections.sum { |e| e_int(e, :collection_cached_count) }
  collection_cache_hit_rate = total_collection_items > 0 ? (total_cached_items.to_f / total_collection_items * 100).round(2) : 0

  {
    total_views_rendered:           total_renders,
    total_view_duration_ms:         total_duration.round(2),
    average_view_duration_ms:       total_renders > 0 ? (total_duration / total_renders).round(2) : 0,
    by_type:                        by_type,
    slowest_views:                  slowest,
    most_frequent_views:            most_frequent,
    partial_cache_hit_rate:         partial_cache_hit_rate,
    collection_cache_hit_rate:      collection_cache_hit_rate,
    total_collection_items:         total_collection_items,
    total_cached_collection_items:  total_cached_items
  }
end

.e_flt(e, key, default = 0.0) ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 142

def self.e_flt(e, key, default = 0.0)
  (e[key] || e[key.to_s] || default).to_f
end

.e_int(e, key, default = 0) ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 138

def self.e_int(e, key, default = 0)
  (e[key] || e[key.to_s] || default).to_i
end

.e_str(e, key, default = "") ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 146

def self.e_str(e, key, default = "")
  (e[key] || e[key.to_s] || default).to_s
end

.safe_identifier(identifier) ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 88

def self.safe_identifier(identifier)
  return "" unless identifier.is_a?(String)
  identifier.split("/").last(3).join("/")
rescue
  identifier.to_s
end

.start_request_tracking ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 39

def self.start_request_tracking
  Thread.current[THREAD_LOCAL_KEY]            = true
  Thread.current[THREAD_LOCAL_AGGREGATES_KEY] = {}
end

.stop_request_tracking ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 44

def self.stop_request_tracking
  Thread.current[THREAD_LOCAL_KEY] = nil
  aggregates = Thread.current[THREAD_LOCAL_AGGREGATES_KEY] || {}
  Thread.current[THREAD_LOCAL_AGGREGATES_KEY] = nil
  aggregates.values.sort_by { |a| [-a[:count], -a[:total_duration_ms]] }
end

.subscribe!(client: Client.new) ⇒ Object 



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# File 'lib/dead_bro/view_rendering_subscriber.rb', line 15

def self.subscribe!(client: Client.new)
  ActiveSupport::Notifications.subscribe(RENDER_TEMPLATE_EVENT) do |_name, started, finished, _uid, data|
    add_view_event(type: "template", identifier: safe_identifier(data[:identifier]),
                   duration_ms: ((finished - started) * 1000.0).round(2),
                   rendered_at: Time.now.utc.to_i)
  end

  ActiveSupport::Notifications.subscribe(RENDER_PARTIAL_EVENT) do |_name, started, finished, _uid, data|
    add_view_event(type: "partial", identifier: safe_identifier(data[:identifier]),
                   duration_ms: ((finished - started) * 1000.0).round(2),
                   cache_key: data[:cache_key],
                   rendered_at: Time.now.utc.to_i)
  end

  ActiveSupport::Notifications.subscribe(RENDER_COLLECTION_EVENT) do |_name, started, finished, _uid, data|
    add_view_event(type: "collection", identifier: safe_identifier(data[:identifier]),
                   duration_ms: ((finished - started) * 1000.0).round(2),
                   collection_count: (data[:count] || 0).to_i,
                   collection_cached_count: (data[:cached_count] || 0).to_i,
                   rendered_at: Time.now.utc.to_i)
  end
rescue
end