Add StackProf-based profiler

nanoc · Jul 9, 2016 · d0c48dc · d0c48dc
1 parent b22c2d8
commit d0c48dc
Showing 1 changed file with 24 additions and 0 deletions.
diff --git a/lib/nanoc/cli/commands/compile.rb b/lib/nanoc/cli/commands/compile.rb
@@ -350,6 +350,29 @@ def log(level, action, path, duration)
       end
     end
 
+    # Records a profile using StackProf
+    class StackProfProfiler < Listener
+      PROFILE_FILE = 'tmp/profile'
+
+      # @see Listener#enable_for?
+      def self.enable_for?(_command_runner)
+        # TODO: Extract
+        ENV.fetch('NANOC_FEAT_PROFILER', 'false') == 'y'
+      end
+
+      # @see Listener#start
+      def start
+        require 'stackprof'
+        StackProf.start(mode: :cpu)
+      end
+
+      # @see Listener#stop
+      def stop
+        StackProf.stop
+        StackProf.results(PROFILE_FILE)
+      end
+    end
+
     attr_accessor :listener_classes
 
     def initialize(options, arguments, command)
@@ -388,6 +411,7 @@ def default_listener_classes
         Nanoc::CLI::Commands::Compile::TimingRecorder,
         Nanoc::CLI::Commands::Compile::GCController,
         Nanoc::CLI::Commands::Compile::FileActionPrinter,
+        Nanoc::CLI::Commands::Compile::StackProfProfiler,
       ]
     end