Benchmark Hash#except

benchmark_except.rb

require 'benchmark/ips'
require 'active_support/hash_with_indifferent_access'
require 'active_support/core_ext/hash'

class Hash
  def except_new(*keys)
    slice(*(self.keys - keys))
  end
end

class ActiveSupport::HashWithIndifferentAccess
  def except_new(*keys)
    slice(*(self.keys - keys.map { |key| convert_key(key) } ))
  end

  alias values_at_old values_at

  def values_at(*keys)
    super(*keys.map { |key| convert_key(key) })
  end
end

HASH = { a: 1, b: 2, c: 3, d:4 }
HASH_WITH_INDIFFERENT_ACCESS = ActiveSupport::HashWithIndifferentAccess.new(HASH)

def new_hash
  HASH.except_new(:b, :d)
end

def old_hash
  HASH.except(:b, :d)
end

def new_with_indifferent_access
  HASH_WITH_INDIFFERENT_ACCESS.except_new(:b, :d)
end

def old_with_indifferent_access
  HASH_WITH_INDIFFERENT_ACCESS.except(:b, :d)
end

Benchmark.ips do |x|
  x.report("Hash new") { new_hash }
  x.report("Hash old") { old_hash }
  x.compare!
end

Benchmark.ips do |x|
  x.report("HashWithIndifferentAccess new") { new_with_indifferent_access }
  x.report("HashWithIndifferentAccess old") { old_with_indifferent_access }
  x.compare!
end