coverband-line-usage-with-hash-benchmark.rb

require 'benchmark/ips'
require 'benchmark/memory'
require 'set'

SIZE = 10_000

def get_number
  rand(1000)
end

def array
  a = []
  SIZE.times do
    n = get_number
    a.push(n) unless a.include?(n)
  end
end

def set
  s = Set.new
  SIZE.times do
    n = get_number
    s << n
  end
end

def hash
  h = Hash.new(0)
  SIZE.times do
    n = get_number
    h[n] += 1
  end
end

def benchmark(x)
  x.report("array: ") { array }
  x.report("set: ") { set }
  x.report("hash: ") { hash }

  x.compare!
end

Benchmark.memory(&method(:benchmark))
Benchmark.ips(&method(:benchmark))

# Results
# Memory Comparison:
#             array: :      11840 allocated
#              hash: :      50136 allocated - 4.23x more
#               set: :      50176 allocated - 4.24x more
#
# Speed Comparasion: 
#               set: :      276.3 i/s
#              hash: :      275.7 i/s - same-ish: difference falls within error
#             array: :       34.4 i/s - 8.04x  slower