Ruby Redis benchmarks for JSON vs Marshal vs String

redis_json_marshal_eval_benchmarks.rb

# http://forrst.com/posts/JSON_vs_Marshal_vs_eval_Which_is_the_fastest_fo-6Qy

require 'benchmark'
require 'json'
require 'redis'

# -----------------

puts "Initialize variables.."

# Initialize connection to Redis via unix socket
redis = Redis.new(path: '/tmp/redis.sock')

# Generate array containing nested hashes with random integers, ex: { 1931 => { 9159 => 9366 }, 'stringkey' => 'stringvalue' }
hashes = []
100000.times do |i|
  hashes[i] = { Random.rand(1..100) => { Random.rand(1..100) => Random.rand(1..100) }, 'stringkey' => 'stringvalue' }
end

puts '-----------------'

puts "Benchmark converting and inserting to Redis\n\n"

# Benchmark converting all the generated hashes into Redis
Benchmark.bm(20) do |x|
  # Convert to json
  x.report('to_json:') {  hashes.each { |h| redis.set 'hash:j', h.to_json }  }
  # "{\"1931\":{\"9159\":9366},\"stringkey\":\"stringvalue\"}"

  # Convert to bytestream
  x.report('Marshal.dump:') {  hashes.each { |h| redis.set 'hash:m', Marshal.dump(h) }  }
  # "\x04\b{\ai\x02\x8B\a{\x06i\x02\xC7#i\x02\x96$I\"\x0Estringkey\x06:\x06EFI\"\x10stringvalue\x06;\x00F"

  # Convert to string
  x.report('hash.to_s:') {  hashes.each { |h| redis.set 'hash:s', h } }
  # "{1931=>{9159=>9366}, \"stringkey\"=>\"stringvalue\"}"
end

puts '-----------------'

puts "Retrieve from Redis to compare\n\n"

# Retrieve from Redis
rawjson = redis.get 'hash:j'
rawbytestream = redis.get 'hash:m'
rawstring = redis.get 'hash:s'

# Convert back to a hash object
json = JSON.parse(rawjson)
bytestream = Marshal.restore(rawbytestream)
string = eval(rawstring)

puts "json == bytestream: #{json == bytestream}" # FALSE
puts "string == bytestream: #{string == bytestream}" # TRUE

puts '-----------------'

puts "Benchmark retrieving from Redis and converting back to a hash\n\n"

# Benchmark converting the hash 100000 times
Benchmark.bm(20) do |x|
  x.report('JSON.parse') { 100000.times { JSON.parse(redis.get 'hash:j') } }
  x.report('Marshal.restore') { 100000.times { Marshal.restore(redis.get 'hash:m') } }
  x.report('eval(string)') { 100000.times { eval(redis.get 'hash:s') } }
end
# 
# 
# 
# Initialize variables..
# -----------------
# Benchmark converting and inserting to Redis
# 
#                            user     system      total        real
# to_json:               4.380000   1.060000   5.440000 (  6.570592)
# Marshal.dump:          2.870000   1.030000   3.900000 (  5.021693)
# hash.to_s:             2.890000   1.010000   3.900000 (  4.997409)
# -----------------
# Retrieve from Redis to compare
# 
# json == bytestream: false
# string == bytestream: true
# -----------------
# Benchmark retrieving from Redis and converting back to a hash
# 
#                            user     system      total        real
# JSON.parse             3.440000   1.070000   4.510000 (  5.497154)
# Marshal.restore        3.130000   1.050000   4.180000 (  5.163987)
# eval(string)           5.130000   1.140000   6.270000 (  7.270163)