benchmarks/hash_functions.rb
require 'benchmark/ips'
require 'digest/md5'
MAX_32_BIT = 4294967295
def jenkins_iterative(string)
hash = 0
string.each_byte do |byte|
hash += byte
hash &= MAX_32_BIT
hash += ((hash << 10) & MAX_32_BIT)
hash &= MAX_32_BIT
hash ^= hash >> 6
end
hash += (hash << 3 & MAX_32_BIT)
hash &= MAX_32_BIT
hash ^= hash >> 11
hash += (hash << 15 & MAX_32_BIT)
hash &= MAX_32_BIT
hash
end
def jenkins_inject(string)
hash = string.each_byte.inject(0) do |byte, hash|
hash += byte
hash &= MAX_32_BIT
hash += ((hash << 10) & MAX_32_BIT)
hash &= MAX_32_BIT
hash ^= hash >> 6
end
hash += (hash << 3 & MAX_32_BIT)
hash &= MAX_32_BIT
hash ^= hash >> 11
hash += (hash << 15 & MAX_32_BIT)
hash &= MAX_32_BIT
hash
end
require 'benchmark/ips'
Benchmark.ips do |x|
x.report("md5") do
Digest::MD5.digest("string")
end
x.report("jenkins iterative") do
jenkins_iterative("string")
end
x.report("jenkins inject") do
jenkins_inject("string")
end
x.compare!
end
__END__
Calculating -------------------------------------
md5 39.416k i/100ms
jenkins iterative 22.646k i/100ms
jenkins inject 18.271k i/100ms
-------------------------------------------------
md5 654.294k (±15.7%) i/s - 3.193M
jenkins iterative 349.669k (±10.3%) i/s - 1.744M
jenkins inject 286.774k (± 5.5%) i/s - 1.443M
Comparison:
md5: 654293.8 i/s
jenkins iterative: 349668.8 i/s - 1.87x slower
jenkins inject: 286774.4 i/s - 2.28x slower