bench.rb

require 'benchmark/ips'

# For comparison
class TransientArray < Array
  def add(x)
    self << x
  end
end

class PersistentArray < Array
  def add(x)
    self.dup << x
  end
end

classes_to_test = []

begin
  require 'persistent_data_structure'
  classes_to_test << Persistent::Vector
rescue LoadError => e
  $stderr.puts "Skipping Persistent::Vector, #{e}"
end

begin
  require 'hamster'
  classes_to_test << Hamster::Vector
rescue LoadError => e
  $stderr.puts "Skipping Hamster::Vector, #{e}"
end

classes_to_test << TransientArray
classes_to_test << PersistentArray

classes_to_test.each do |klass|
  Benchmark.ips do |x|
    ary = [*1..100000]

    x.report "#{klass} from Array" do
      vector = klass[*ary]
    end

    x.report "#{klass}#add" do
      v = klass[*ary]
      100000.times { |i| v = v.add(i) }
    end
  end
end

result.txt

Compares Persistent::Vector, Hamster::Vector, arrays with transient semantics and arrays with persistent (copy before update) semantics. Requires a modified Hamster for Hamster::Vector[].

$ jruby --version
jruby 9000.dev-SNAPSHOT (2.1.2) 2014-05-01 ae5ad64 on OpenJDK 64-Bit Server VM 1.7.0_55-b14 [linux-amd64]

$ java -version
java version "1.7.0_55"
OpenJDK Runtime Environment (IcedTea 2.4.7) (7u55-2.4.7-1ubuntu1)
OpenJDK 64-Bit Server VM (build 24.51-b03, mixed mode)

$ RUBYOPT='-I../persistent_data_structures/lib -I../hamster/lib' ruby bench/bench.rb

Calculating -------------------------------------
Persistent::Vector from Array
                            18 i/100ms
Persistent::Vector#add
                             2 i/100ms
-------------------------------------------------
Persistent::Vector from Array
                          289.7 (±4.5%) i/s -       1458 in   5.044000s
Persistent::Vector#add
                           25.7 (±11.7%) i/s -        128 in   5.072000s
Calculating -------------------------------------
Hamster::Vector from Array
                             1 i/100ms
 Hamster::Vector#add         1 i/100ms
-------------------------------------------------
Hamster::Vector from Array
                            0.6 (±0.0%) i/s -          3 in   5.414000s
 Hamster::Vector#add        0.3 (±0.0%) i/s -          2 in   7.016000s
Calculating -------------------------------------
TransientArray from Array
                           865 i/100ms
  TransientArray#add         6 i/100ms
-------------------------------------------------
TransientArray from Array
                         9543.7 (±5.8%) i/s -      47575 in   5.002000s
  TransientArray#add       69.7 (±7.2%) i/s -        348 in   5.026000s
Calculating -------------------------------------
PersistentArray from Array
                           878 i/100ms
 PersistentArray#add         1 i/100ms
-------------------------------------------------
PersistentArray from Array
                         9611.0 (±3.6%) i/s -      48290 in   5.031000s
 PersistentArray#add        0.0 (±0.0%) i/s -          1 in  42.951000s