BSON::Document + symbols VS #to_h + strings

bson_symbols_vs_hash_strings.rb

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"
  gem "bson"
  gem "benchmark-ips"
end

SYMBOLS = [:a, :b, :c, :d, :e, :f, :g, :h, :i].freeze
STRINGS = ["a", "b", "c", "d", "e", "f", "g", "h", "i"].freeze
STRINGS.each(&:freeze)
DOC = BSON::Document.new(
  "a" => 1,
  "b" => 2,
  "c" => 3,
  "d" => 4,
  "e" => 5,
  "f" => 6,
  "g" => 7,
  "h" => 8,
  "i" => 9
).freeze


GC.start
GC.disable
Benchmark.ips do |x|
  x.report("BSON document") do
    SYMBOLS.each do |s|
      DOC[s]
    end
  end
  x.report("Hash") do
    doc = DOC.to_h
    STRINGS.each do |s|
      doc[s]
    end
  end
  x.compare!
end
__END__
Warming up --------------------------------------
       BSON document    45.712k i/100ms
                Hash    62.576k i/100ms
Calculating -------------------------------------
       BSON document    580.713k (± 3.6%) i/s -      2.926M in   5.044795s
                Hash    845.759k (± 4.3%) i/s -      4.255M in   5.041228s

Comparison:
                Hash:   845759.2 i/s
       BSON document:   580713.4 i/s - 1.46x slower