Add instrumentation for slow response processing

Author: Thibaut

lib/docs/core/requester.rb

@@ -1,5 +1,7 @@
 module Docs
   class Requester < Typhoeus::Hydra
+    include Instrumentable
+
     attr_reader :request_options
 
     def self.run(urls, options = {}, &block)
@@ -52,9 +54,11 @@ def build_and_queue_request(url, options, &block)
     end
 
     def handle_response(response)
-      on_response.each do |callback|
-        result = callback.call(response)
-        result.each { |url| request(url) } if result.is_a? Array
+      instrument 'handle_response.requester', url: response.url do
+        on_response.each do |callback|
+          result = callback.call(response)
+          result.each { |url| request(url) } if result.is_a?(Array)
+        end
       end
     end
   end

lib/docs/subscribers/requester_subscriber.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Docs
+  class RequesterSubscriber < Subscriber
+    self.namespace = 'requester'
+
+    def handle_response(event)
+      if event.duration > 10_000
+        log "WARN: #{format_url event.payload[:url]} was slow to process (#{(event.duration / 1000).round}s)"
+      end
+    end
+  end
+end

lib/tasks/docs.thor

@@ -62,7 +62,7 @@ class DocsCLI < Thor
     Docs.rescue_errors = true
     Docs.install_report :store if options[:verbose]
     Docs.install_report :scraper if options[:debug]
-    Docs.install_report :progress_bar, :doc, :image if $stdout.tty?
+    Docs.install_report :progress_bar, :doc, :image, :requester if $stdout.tty?
 
     require 'unix_utils' if options[:package]