[macruby-changes] [MacRuby/MacRuby] 6beac7: improve a performance in String#== and String#eql?

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/MacRuby/MacRuby
  Commit: 6beac71eb495bb0592954a5cdd81906347cdfe12
      https://github.com/MacRuby/MacRuby/commit/6beac71eb495bb0592954a5cdd81906347cdfe12
  Author: Watson <watson1978 at gmail.com>
  Date:   2012-12-29 (Sat, 29 Dec 2012)

  Changed paths:
    M string.c

  Log Message:
  -----------
  improve a performance in String#== and String#eql?

When the length of the string does not match, it will not need to invoke a memcmp().

* before
    user     system      total        real
==    0.230000   0.000000   0.230000 (  0.233827)
eql?  0.230000   0.000000   0.230000 (  0.227859)

* after
      user     system      total        real
==     0.020000   0.000000   0.020000 (  0.014583)
eql?   0.010000   0.000000   0.010000 (  0.015350)

Test Code:
----
require 'benchmark'

str = "abc" * 100
str1 = str * 100
str2 = str * 200

Benchmark.bm(4) do |x|
  x.report "==" do
    100000.times do
      str1 == str2
    end
  end

  x.report "eql?" do
    100000.times do
      str1.eql? str2
    end
  end
end