[ruby/irb] Add measure command

You can use "measure" command to check performance in IRB like below:

  irb(main):001:0> 3
  => 3
  irb(main):002:0> measure
  TIME is added.
  => nil
  irb(main):003:0> 3
  processing time: 0.000058s
  => 3
  irb(main):004:0> measure :off
  => nil
  irb(main):005:0> 3
  => 3

You can set "measure :on" by "IRB.conf[:MEASURE] = true" in .irbrc, and, also,
set custom performance check method:

  IRB.conf[:MEASURE_PROC][:CUSTOM] = proc { |context, code, line_no, &block|
    time = Time.now
    result = block.()
    now = Time.now
    puts 'custom processing time: %fs' % (Time.now - time) if IRB.conf[:MEASURE]
    result
  }

https://github.com/ruby/irb/commit/3899eaf2e2

1 files changed, 17 insertions, 1 deletions

diff --git a/lib/irb.rb b/lib/irb.rb
index 579fd67c67..26c5d2ebe9 100644
--- a/lib/irb.rb
+++ b/lib/irb.rb
@@ -538,7 +538,23 @@ module IRB
         signal_status(:IN_EVAL) do
           begin
             line.untaint if RUBY_VERSION < '2.7'
-            @context.evaluate(line, line_no, exception: exc)
+            if IRB.conf[:MEASURE] && IRB.conf[:MEASURE_CALLBACKS].empty?
+              IRB.set_measure_callback
+            end
+            if IRB.conf[:MEASURE] && !IRB.conf[:MEASURE_CALLBACKS].empty?
+              result = nil
+              last_proc = proc{ result = @context.evaluate(line, line_no, exception: exc) }
+              IRB.conf[:MEASURE_CALLBACKS].map{ |s| s.last }.inject(last_proc) { |chain, item|
+                proc {
+                  item.(@context, line, line_no, exception: exc) do
+                    chain.call
+                  end
+                }
+              }.call
+              @context.set_last_value(result)
+            else
+              @context.evaluate(line, line_no, exception: exc)
+            end
             if @context.echo?
               if assignment_expression?(line)
                 if @context.echo_on_assignment?