record_accessor: Make code simple and bit faster

[repeatedly]

Signed-off-by: Masahiro Nakagawa repeatedly@gmail.com

Which issue(s) this PR fixes:
None

What this PR does / why we need it:
Make record_accessor code simple by moving call_index to default implementation.
New implementation is bit faster.

Warming up --------------------------------------
                base   317.029k i/100ms
                test   327.406k i/100ms
Calculating -------------------------------------
                base     10.600M (± 6.1%) i/s -     52.944M in   5.019043s
                test     10.797M (± 4.2%) i/s -     54.022M in   5.013882s

Docs Changes:
No need

Release Note:
Same as title.

[ganmacs]

Code is good.
But I have a question. what made code a bit faster? what kind of benchmark script did you use?

[repeatedly]

Ah, I forgot to paste the code.

require 'benchmark/ips'

class Base
  def initialize
    @keys = 'k'
    mcall = method(:call_index)
    singleton_class.module_eval do
      define_method(:call, mcall)
    end
  end

  def call(r)
  end

  def call_dig(r)
    r.dig(*@keys)
  end

  def call_index(r)
    r[@keys]
  end
end

class Test
  def initialize
    @keys = 'k'
  end

  def call(r)
    r[@keys]
  end

  def call_dig(r)
    r.dig(*@keys)
  end
end

record = {'k' => 'foo'}
base = Base.new
test = Test.new

Benchmark.ips do |x|
  x.report "base" do
    base.call(record)
  end

  x.report "test" do
    test.call(record)
  end
end

[ganmacs]

I see. made it faster when using a default implementation 👍