gistfile1.rb

require 'benchmark'

A = 'a'
B = 'b'
C = 'c'
D = 'd'
E = 'e'
F = 'f'
G = 'g'
H = 'h'
I = 'i'
NOPE = 'nope'

def literal
  {
    A => rand,
    B => rand,
    C => rand,
    D => rand,
    E => rand,
    F => rand,
    G => rand,
    H => rand,
    I => rand
  }
end

class Key < String
  attr_reader :hash

  def initialize(string)
    super(string)
    @hash = string.hash
    freeze
  end
end

def k(str)
  Key.new(str)
end

KA = k('a')
KB = k('b')
KC = k('c')
KD = k('d')
KE = k('e')
KF = k('f')
KG = k('g')
KH = k('h')
KI = k('i')
KNOPE = k('nope')

def literal2
  {
    KA => rand,
    KB => rand,
    KC => rand,
    KD => rand,
    KE => rand,
    KF => rand,
    KG => rand,
    KH => rand,
    KI => rand
  }
end

n = 500000
Benchmark.bmbm(7) do |x|
  x.report("literal:") { n.times { h = literal; h[KF]; h[NOPE] } }
  x.report("literal2:") { n.times { h = literal2; h[KF]; h[KNOPE] } }
end

gistfile2.txt

jruby 1.7.1 (1.9.3p327) 2012-12-03 30a153b on Java HotSpot(TM) 64-Bit Server VM 1.6.0_35-b10-428-10M3811 [darwin-x86_64]
Rehearsal ---------------------------------------------
literal:    2.600000   0.060000   2.660000 (  1.304000)
literal2:   1.380000   0.050000   1.430000 (  0.745000)
------------------------------------ total: 4.090000sec

                user     system      total        real
literal:    0.740000   0.030000   0.770000 (  0.740000)
literal2:   0.610000   0.020000   0.630000 (  0.598000)