3 files changed, 93 insertions, 0 deletions
diff --git a/lib/irb/cmd/measure.rb b/lib/irb/cmd/measure.rb
new file mode 100644
index 0000000000..6161d15bcb
--- /dev/null
+++ b/lib/irb/cmd/measure.rb
@@ -0,0 +1,34 @@
+require_relative "nop"
+
+# :stopdoc:
+module IRB
+  module ExtendCommand
+    class Measure < Nop
+      def initialize(*args)
+        super(*args)
+      end
+
+      def execute(type = nil, arg = nil)
+        case type
+        when :off
+          IRB.conf[:MEASURE] = nil
+          IRB.unset_measure_callback(arg)
+        when :list
+          IRB.conf[:MEASURE_CALLBACKS].each do |type_name, _|
+            puts "- #{type_name}"
+          end
+        when :on
+          IRB.conf[:MEASURE] = true
+          added = IRB.set_measure_callback(type)
+          puts "#{added.first} is added."
+        else
+          IRB.conf[:MEASURE] = true
+          added = IRB.set_measure_callback(type)
+          puts "#{added.first} is added."
+        end
+        nil
+      end
+    end
+  end
+end
+# :startdoc:
diff --git a/lib/irb/extend-command.rb b/lib/irb/extend-command.rb
index 3cd0c515f1..55e7b3e0e6 100644
--- a/lib/irb/extend-command.rb
+++ b/lib/irb/extend-command.rb
@@ -125,6 +125,10 @@ module IRB # :nodoc:
         :irb_info, :Info, "irb/cmd/info"
       ],
 
+      [
+        :measure, :Measure, "irb/cmd/measure"
+      ],
+
     ]
 
     # Installs the default irb commands:
diff --git a/lib/irb/init.rb b/lib/irb/init.rb
index 73ef420e60..f17d316c43 100644
--- a/lib/irb/init.rb
+++ b/lib/irb/init.rb
@@ -111,11 +111,66 @@ module IRB # :nodoc:
     @CONF[:CONTEXT_MODE] = 4 # use a copy of TOPLEVEL_BINDING
     @CONF[:SINGLE_IRB] = false
 
+    @CONF[:MEASURE] = false
+    @CONF[:MEASURE_PROC] = {}
+    @CONF[:MEASURE_PROC][:TIME] = proc { |context, code, line_no, &block|
+      time = Time.now
+      result = block.()
+      now = Time.now
+      puts 'processing time: %fs' % (now - time) if IRB.conf[:MEASURE]
+      result
+    }
+    @CONF[:MEASURE_PROC][:STACKPROF] = proc { |context, code, line_no, &block|
+      success = false
+      begin
+        require 'stackprof'
+        success = true
+      rescue LoadError
+        puts 'Please run "gem install stackprof" before measuring by StackProf.'
+      end
+      if success
+        result = nil
+        stackprof_result = StackProf.run(mode: :cpu) do
+          result = block.()
+        end
+        StackProf::Report.new(stackprof_result).print_text if IRB.conf[:MEASURE]
+        result
+      else
+        block.()
+      end
+    }
+    @CONF[:MEASURE_CALLBACKS] = []
+
     @CONF[:LC_MESSAGES] = Locale.new
 
     @CONF[:AT_EXIT] = []
   end
 
+  def IRB.set_measure_callback(type = nil)
+    added = nil
+    if type
+      type_sym = type.upcase.to_sym
+      if IRB.conf[:MEASURE_PROC][type_sym]
+        added = [type_sym, IRB.conf[:MEASURE_PROC][type_sym]]
+      end
+    elsif IRB.conf[:MEASURE_PROC][:CUSTOM]
+      added = [:CUSTOM, IRB.conf[:MEASURE_PROC][:CUSTOM]]
+    else
+      added = [:TIME, IRB.conf[:MEASURE_PROC][:TIME]]
+    end
+    IRB.conf[:MEASURE_CALLBACKS] << added if added
+    added
+  end
+
+  def IRB.unset_measure_callback(type = nil)
+    if type.nil?
+      IRB.conf[:MEASURE_CALLBACKS].clear
+    else
+      type_sym = type.upcase.to_sym
+      IRB.conf[:MEASURE_CALLBACKS].reject!{ |t, c| t == type_sym }
+    end
+  end
+
   def IRB.init_error
     @CONF[:LC_MESSAGES].load("irb/error.rb")
   end