test.rb

require 'Benchmark'
require 'java'    
require 'jruby/profiler'

java_import java.util.TreeMap

# data to mess with
values = (0..10000).map { (0..8).map{ ('a'..'z').to_a[rand(26)] }.join }

cmp = Proc.new {|a,b|a <=> b }

class Compare
  java_implements java.util.Comparator
  
  java_signature 'int compare(java.lang.Object,java.lang.Object)'
  def compare(a, b)
    a <=> b
  end
end

class DelegatingCompare
  java_implements java.util.Comparator
  def initialize &block
    @proc = block.to_proc
  end                    
  
  java_signature 'int compare(java.lang.Object,java.lang.Object)'
  def compare(a, b)
    @proc.call(a, b)
  end
end

                  

Benchmark.bmbm do |x|
  def load_and_clear_map(map,values)
    100.times do 
      values.each { |v| map.put(v,v) }
      map.clear()
    end
  end
  
  x.report("with Proc") do
    map = TreeMap.java_class.constructor(java::util::Comparator).new_instance(cmp).to_java
    load_and_clear_map(map,values)
  end
  x.report("class Compare") do
    map = TreeMap.java_class.constructor(java::util::Comparator).new_instance(Compare.new).to_java
    load_and_clear_map(map,values)
  end
  x.report("class DelegatingCompare") do
    map = TreeMap.java_class.constructor(java::util::Comparator).new_instance(DelegatingCompare.new {|a,b| a <=> b}).to_java
    load_and_clear_map(map,values)
  end
  
end