rack utils optimizations

rack_utils_optimizations.rb

require 'benchmark'
require 'rack'

include Rack::Utils

# This illustrates the little optimizations to Rack::Utils that you might
# consider.  The parse_query optimization prevents the regeneration of the
# default separator regexp:
#
#   /[#{d}] */n
#
# While the build_query optimization works because:
#
#   "#{a}=#{b}"
#
# is apparently faster than:
#
#   a + "=" + b
#
# Of course benchmarks can lie, but I thought you might be interested.
# 
# - Simon
#
# 
#
# == commit d221938a6401d956ac6cfdc892f9b1c11b1fa31a (original)
#
# % ruby -Ilib test/benchmark/rack_utils_benchmark.rb 
#                                user     system      total        real
# 20k x parse_query (a)      0.990000   0.000000   0.990000 (  1.000777)
# 20k x parse_query (b)      1.010000   0.010000   1.020000 (  1.021451)
# 30k x build_query          1.000000   0.000000   1.000000 (  1.006995)
#
# == commit 9e4a325ff2e39e056918d32cf2216fb902cb675d (optimized)
#
# ruby -Ilib test/benchmark/rack_utils_benchmark.rb 
#                                user     system      total        real
# 20k x parse_query (a)      0.870000   0.000000   0.870000 (  0.880443)
# 20k x parse_query (b)      0.890000   0.010000   0.900000 (  0.903522)
# 30k x build_query          0.960000   0.000000   0.960000 (  0.969581)
#
# ~ 10% speedup for parse_query
# ~ 4% speedup for build_query
#
Benchmark.bm(25) do |x|
  
  str = "foo=bar&foo=quux&foo=baz&foo=quud&a=b"
  x.report("20k x parse_query (a)") do
    20000.times do
      parse_query(str)
    end
  end
  
  str = "my+weird+field=q1%212%22%27w%245%267%2Fz8%29%3F"
  x.report("20k x parse_query (b)") do
    20000.times do
      parse_query(str)
    end
  end

  query = {"foo" => "1", "bar" => "2", "baz" => "3", "quux" => "4"}
  x.report("30k x build_query") do
    30000.times do
      build_query(query)
    end
  end
end