Benchmarks grit's ruby cat-file vs. native (sh) cat-file implementations

bench-string-concat.rb

# Put this in your grit working directory and run with one of these blobs:
#
# large blob:   12044a76034e894c2412aea9c20508b5c8277784
# medium blob:  ab9d58aaebdb25385a21129b16e386fdaeee4b63
# small blob:   be391a3318952a73eaad63fd988ab1e201386965
#
# Like this:
#
# ruby bench-string-concat.rb 12044a76034e894c2412aea9c20508b5c8277784

$: << File.expand_path('lib')
require 'grit'

Grit::Git.git_max_size = 1_000_000_000
git = Grit::Git.new('.git')

blob = ARGV.first
size = git.native(:cat_file, {:s => true}, blob).to_i

puts "blob: #{blob}"
puts "size: #{size}"

require 'benchmark'
include Benchmark

bm(30) do |measure|
  measure.report("native cat_file") {
    100.times {
      data = git.native(:cat_file, {:p => true}, blob)
      fail if data.size != size
    }
  }
  measure.report("ruby cat_file") {
    100.times {
      data = git.cat_file({:p => true}, blob)
      fail if data.size != size
    }
  }
end