compile.rb in nanoc-4.2.4

- old
+ new

@@ -12,10 +12,11 @@
 IDENTICAL - The item was deemed outdated and has been recompiled, but the compiled version turned out to be identical to the already existing version
 
 SKIP - The item was deemed not outdated and was therefore not recompiled
 
 EOS
+flag nil, :profile, 'profile compilation' if Nanoc::Feature.enabled?('PROFILER')
 
 module Nanoc::CLI::Commands
   class Compile < ::Nanoc::CLI::CommandRunner
     # Listens to compilation events and reacts to them. This abstract class
     # does not have a real implementation; subclasses should override {#start}
@@ -47,10 +48,22 @@
       # Stops the listener. The default implementation removes self from all notification center observers.
       #
       # @return [void]
       def stop
       end
+
+      # @api private
+      def start_safely
+        start
+        @_started = true
+      end
+
+      # @api private
+      def stop_safely
+        stop if @_started
+        @_started = false
+      end
     end
 
     # Generates diffs for every output file written
     class DiffGenerator < Listener
       # @see Listener#enable_for?
@@ -61,14 +74,14 @@
       # @see Listener#start
       def start
         require 'tempfile'
         setup_diffs
         old_contents = {}
-        Nanoc::Int::NotificationCenter.on(:will_write_rep) do |rep, path|
+        Nanoc::Int::NotificationCenter.on(:will_write_rep, self) do |rep, path|
           old_contents[rep] = File.file?(path) ? File.read(path) : nil
         end
-        Nanoc::Int::NotificationCenter.on(:rep_written) do |rep, path, _is_created, _is_modified|
+        Nanoc::Int::NotificationCenter.on(:rep_written, self) do |rep, path, _is_created, _is_modified|
           unless rep.binary?
             new_contents = File.file?(path) ? File.read(path) : nil
             if old_contents[rep] && new_contents
               generate_diff_for(path, old_contents[rep], new_contents)
             end
@@ -78,10 +91,14 @@
       end
 
       # @see Listener#stop
       def stop
         super
+
+        Nanoc::Int::NotificationCenter.remove(:will_write_rep, self)
+        Nanoc::Int::NotificationCenter.remove(:rep_written, self)
+
         teardown_diffs
       end
 
       protected
 
@@ -348,10 +365,32 @@
       def log(level, action, path, duration)
         Nanoc::CLI::Logger.instance.file(level, action, path, duration)
       end
     end
 
+    # Records a profile using StackProf
+    class StackProfProfiler < Listener
+      PROFILE_FILE = 'tmp/stackprof_profile'.freeze
+
+      # @see Listener#enable_for?
+      def self.enable_for?(command_runner)
+        command_runner.options.fetch(:profile, false)
+      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)
       super
       @listener_classes = default_listener_classes
@@ -386,20 +425,21 @@
         Nanoc::CLI::Commands::Compile::DiffGenerator,
         Nanoc::CLI::Commands::Compile::DebugPrinter,
         Nanoc::CLI::Commands::Compile::TimingRecorder,
         Nanoc::CLI::Commands::Compile::GCController,
         Nanoc::CLI::Commands::Compile::FileActionPrinter,
+        Nanoc::CLI::Commands::Compile::StackProfProfiler,
       ]
     end
 
     def setup_listeners
       @listeners =
         @listener_classes
         .select { |klass| klass.enable_for?(self) }
         .map    { |klass| klass.new(reps: reps) }
 
-      @listeners.each(&:start)
+      @listeners.each(&:start_safely)
     end
 
     def listeners
       @listeners
     end
@@ -410,10 +450,10 @@
     ensure
       teardown_listeners
     end
 
     def teardown_listeners
-      @listeners.each(&:stop)
+      @listeners.each(&:stop_safely)
     end
 
     def reps
       site.compiler.reps
     end