benchmark

gistfile1.txt

require 'pry'
require 'benchmark'
require 'benchmark-memory'
class User

  def initialize( args = {} )
    raise 'user_ids needs to be an array' unless args[:user_ids].is_a?(Array)
    @user_ids = args[:user_ids]
  end

  def top_user_ids_0(k)
    results = Hash.new{ |k, v| k[ v ] = 0 }
    @user_ids.each { |id| results[ id ] += 1 }
    results.sort_by{ |k, v| v <=> v}[0, k].map{ |u| u[0]}
  end

  def top_user_ids_3(k)
    results = Hash.new{ |k, v| k[ v ] = 0 }
    @user_ids.each { |id| 
      results[ id ] += 1 
    }.sort_by{ |k, v| 
      v <=> v
    }[0, k].map{ |u| 
      u[0]
    }
  end

  def top_user_ids_1(k)
    @user_ids.group_by{ 
      |k| k 
    }.sort_by{ |k, v| 
      v.count <=> v.count 
    }.first( k ).map{ |d| d[0] }
  end

  def top_user_ids_2(k)
    @user_ids.each_with_object( Hash.new( 0 ) ){ |user_id, counts| 
      counts[user_id] += 1 
    }.sort_by{ |k, v| 
      v <=> v
    }[0, k].map{ |u| 
      u[0] 
    }
  end

  def self.test_a_method(n)
    k = 4
    array = [1,1, 3, 4, 6, 7,3, 1, 6, 8, 8, 8, 8, 8, 2, 1 ] 
    u = User.new( user_ids: array )
    u.send("top_user_ids_#{ n }", k )
  end

  def self.benchmark
    array = [1,1, 3, 4, 6, 7,3, 1, 6, 8, 8, 8, 8, 8, 2, 1 ] * 1000000
    u = User.new( user_ids: array )
    x = 10000
    k = 3
    Benchmark.bm do |x|
      [ 0, 1, 2, 3 ].each do |n|
        start_time = Time.now
        x.report("top_user_ids_#{ n }") { u.send("top_user_ids_#{ n }", k) }
        puts "#{ "top_user_ids_#{ n }" } #{ Time.now - start_time }"
      end
    end
  end
  
  def self.benchmark_mem
    array = [1,1, 3, 4, 6, 7,3, 1, 6, 8, 8, 8, 8, 8, 2, 1 ] * 1000000
    u = User.new( user_ids: array )
    x = 10000
    k = 3
    Benchmark.memory do |x|
      [ 0, 1, 2, 3 ].each do |n|
        x.report("top_user_ids_#{ n }") { u.send("top_user_ids_#{ n }", k) }
      end
      x.compare!
    end
  end

end
# User.benchmark
User.benchmark_mem
# User.test_a_method(3)