From: Matt Armstrong <matt@...>
Date: 2002-02-06T02:04:33+09:00
Subject: A case where 1.7 is slower than 1.6

It seems that File#readlines (and similar operations) got
significantly slower in ruby 1.7.

My test results:

    % ruby huge.rb
    This is 1.6.5 2001-11-28 i386-linux
    read huge file into an array: 3.210000 sec

    % ruby-cvs huge.rb
    This is 1.7.2 2002-02-04 i686-linux
    read huge file into an array: 5.733333 sec

And the test program:

if Process.respond_to? :times then
  TIMES_MODULE = Process
else
  TIMES_MODULE = Time
end

def benchmark( label, times, &block )
  begtime = TIMES_MODULE.times.utime
  times.times( &block )
  endtime = TIMES_MODULE.times.utime
  puts "%s: %f sec" % [ label, endtime - begtime ]
end

File.open("huge_file", "w") do |f|
  s = 'a' * 80
  0.upto(100000) do
    f.puts s
  end
end

puts "This is %s %s %s" % [ RUBY_VERSION, RUBY_RELEASE_DATE, RUBY_PLATFORM ]

benchmark("read huge file into an array", 1) do
  data = []
  File.open("huge_file") do |f|
    f.each_line do |line|
      data << line
    end
  end
end

File.delete("huge_file")


-- 
matt