leaderboard

Leaderboards backed by Redis in Ruby, http://redis.io.

Builds off ideas proposed in http://blog.agoragames.com/2011/01/01/creating-high-score-tables-leaderboards-using-redis/.

Installation

gem install leaderboard

or in your Gemfile

gem 'leaderboard'

Make sure your redis server is running! Redis configuration is outside the scope of this README, but check out the Redis documentation, http://redis.io/documentation.

Compatibility

The gem has been built and tested under Ruby 1.8.7, Ruby 1.9.2 and Ruby 1.9.3.

The gem is compatible with Redis 2.4.x and Redis 2.6.x.

Usage

Creating a leaderboard

Create a new leaderboard or attach to an existing leaderboard named 'highscores':

  highscore_lb = Leaderboard.new('highscores')
   => #<Leaderboard:0x0000010307b530 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://localhost:6379/0 (Redis v2.2.5)>>

If you need to pass in options for Redis, you can do this in the initializer:

  redis_options = {:host => 'localhost', :port => 6379, :db => 1}
   => {:host=>"localhost", :port=>6379, :db=>1} 
  highscore_lb = Leaderboard.new('highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)
   => #<Leaderboard:0x00000103095200 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://localhost:6379/1 (Redis v2.2.5)>> 

Defining leaderboard options

The Leaderboard::DEFAULT_OPTIONS are as follows:

DEFAULT_OPTIONS = {
  :page_size => DEFAULT_PAGE_SIZE,
  :reverse => false
}

The DEFAULT_PAGE_SIZE is 25.

You would use the option, :reverse => true, if you wanted a leaderboard sorted from lowest-to-highest score. You may also set the reverse option on a leaderboard after you have created a new instance of a leaderboard.

You can pass in an existing connection to Redis using :redis_connection in the Redis options hash:

  redis = Redis.new
   => #<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)> 
  redis_options = {:redis_connection => redis}
   => {:redis_connection=>#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>} 
  highscore_lb = Leaderboard.new('highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)
   => #<Leaderboard:0x000001028791e8 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>> 

To use the same connection for multiple leaderboards, reset the options hash before instantiating more leaderboards:

redis = Redis.new
 => #<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)> 
redis_options = {:redis_connection => redis}
 => {:redis_connection=>#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>} 
highscore_lb = Leaderboard.new('highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)
redis_options = {:redis_connection => redis}
other_highscore_lb = Leaderboard.new('other_highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)

You can set the page size to something other than the default page size (25):

  highscore_lb.page_size = 5
   => 5 
  highscore_lb
   => #<Leaderboard:0x000001028791e8 @leaderboard_name="highscores", @page_size=5, @redis_connection=#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>> 

Ranking members in the leaderboard

Add members to your leaderboard using rank_member:

  1.upto(10) do |index|
    highscore_lb.rank_member("member_#{index}", index)
  end
   => 1 

You can call rank_member with the same member and the leaderboard will be updated automatically.

Get some information about your leaderboard:

  highscore_lb.total_members
   => 10 
  highscore_lb.total_pages
   => 1 

The rank_member call will also accept an optional hash of member data that could be used to store other information about a given member in the leaderboard. This may be useful in situations where you are storing member IDs in the leaderboard and you want to be able to store a member name for display. Example:

highscore_lb.rank_member('84849292', 1, {'username' => 'member_name'})

You can retrieve, update and remove the optional member data using the member_data_for, update_member_data and remove_member_data calls. Example:

highscore_lb.member_data_for('84849292')
 => {"username"=>"member_name"}

highscore_lb.update_member_data('84849292', {'last_updated' => Time.now, 'username' => 'updated_member_name'})
 => "OK" 
highscore_lb.member_data_for('84849292')
 => {"username"=>"updated_member_name", "last_updated"=>"2012-06-09 09:11:06 -0400"}

highscore_lb.remove_member_data('84849292')

Get some information about a specific member(s) in the leaderboard:

  highscore_lb.score_for('member_4')
   => 4.0 
  highscore_lb.rank_for('member_4')
   => 7 
  highscore_lb.rank_for('member_10')
   => 1 

Retrieving members from the leaderboard

Get page 1 in the leaderboard:

  highscore_lb.leaders(1)
   => [{:member=>"member_10", :rank=>1, :score=>10.0}, {:member=>"member_9", :rank=>2, :score=>9.0}, {:member=>"member_8", :rank=>3, :score=>8.0}, {:member=>"member_7", :rank=>4, :score=>7.0}, {:member=>"member_6", :rank=>5, :score=>6.0}, {:member=>"member_5", :rank=>6, :score=>5.0}, {:member=>"member_4", :rank=>7, :score=>4.0}, {:member=>"member_3", :rank=>8, :score=>3.0}, {:member=>"member_2", :rank=>9, :score=>2.0}, {:member=>"member_1", :rank=>10, :score=>1.0}] 

You can pass various options to the calls leaders, around_me and ranked_in_list. Valid options are :with_scores, :with_rank, :with_member_data, :use_zero_index_for_rank and :page_size. Below is an example of retrieving the first page in the leaderboard without ranks:

  highscore_lb.leaders(1, :with_rank => false)
   => [{:member=>"member_10", :score=>9.0}, {:member=>"member_9", :score=>7.0}, {:member=>"member_8", :score=>5.0}, {:member=>"member_7", :score=>3.0}, {:member=>"member_6", :score=>1.0}, {:member=>"member_5", :score=>0.0}, {:member=>"member_4", :score=>0.0}, {:member=>"member_3", :score=>0.0}, {:member=>"member_2", :score=>0.0}, {:member=>"member_1", :score=>0.0}] 

Below is an example of retrieving the first page in the leaderboard without scores or ranks:

  highscore_lb.leaders(1, :with_scores => false, :with_rank => false)
   => [{:member=>"member_10"}, {:member=>"member_9"}, {:member=>"member_8"}, {:member=>"member_7"}, {:member=>"member_6"}, {:member=>"member_5"}, {:member=>"member_4"}, {:member=>"member_3"}, {:member=>"member_2"}, {:member=>"member_1"}] 

Add more members to your leaderboard:

  50.upto(95) do |index|
    highscore_lb.rank_member("member_#{index}", index)
  end
   => 50 
  highscore_lb.total_pages
   => 3 

Get an "Around Me" leaderboard page for a given member, which pulls members above and below the given member:

  highscore_lb.around_me('member_53')
   => [{:member=>"member_65", :rank=>31, :score=>65.0}, {:member=>"member_64", :rank=>32, :score=>64.0}, {:member=>"member_63", :rank=>33, :score=>63.0}, {:member=>"member_62", :rank=>34, :score=>62.0}, {:member=>"member_61", :rank=>35, :score=>61.0}, {:member=>"member_60", :rank=>36, :score=>60.0}, {:member=>"member_59", :rank=>37, :score=>59.0}, {:member=>"member_58", :rank=>38, :score=>58.0}, {:member=>"member_57", :rank=>39, :score=>57.0}, {:member=>"member_56", :rank=>40, :score=>56.0}, {:member=>"member_55", :rank=>41, :score=>55.0}, {:member=>"member_54", :rank=>42, :score=>54.0}, {:member=>"member_53", :rank=>43, :score=>53.0}, {:member=>"member_52", :rank=>44, :score=>52.0}, {:member=>"member_51", :rank=>45, :score=>51.0}, {:member=>"member_50", :rank=>46, :score=>50.0}, {:member=>"member_10", :rank=>47, :score=>10.0}, {:member=>"member_9", :rank=>48, :score=>9.0}, {:member=>"member_8", :rank=>49, :score=>8.0}, {:member=>"member_7", :rank=>50, :score=>7.0}, {:member=>"member_6", :rank=>51, :score=>6.0}, {:member=>"member_5", :rank=>52, :score=>5.0}, {:member=>"member_4", :rank=>53, :score=>4.0}, {:member=>"member_3", :rank=>54, :score=>3.0}, {:member=>"member_2", :rank=>55, :score=>2.0}] 

Get rank and score for an arbitrary list of members (e.g. friends) from the leaderboard:

  highscore_lb.ranked_in_list(['member_1', 'member_62', 'member_67'])
   => [{:member=>"member_1", :rank=>56, :score=>1.0}, {:member=>"member_62", :rank=>34, :score=>62.0}, {:member=>"member_67", :rank=>29, :score=>67.0}]

Ranking multiple members in a leaderboard at once

Insert multiple data items for members and their associated scores:

As a splat:

highscore_lb.rank_members('member_1', 1, 'member_5', 5, 'member_10', 10)

Or as an array:

highscore_lb.rank_members(['member_1', 1, 'member_5', 5, 'member_10', 10])

Use this method to do bulk insert of data, but be mindful of the amount of data you are inserting since a single transaction can get quite large.

Other useful methods

  delete_leaderboard: Delete the current leaderboard
  member_data_for(member): Retrieve the optional member data for a given member in the leaderboard
  update_member_data(member, member_data): Update the optional member data for a given member in the leaderboard
  remove_member_data(member): Remove the optional member data for a given member in the leaderboard
  remove_member(member): Remove a member from the leaderboard
  total_members: Total # of members in the leaderboard
  total_pages: Total # of pages in the leaderboard given the leaderboard's page_size    
  total_members_in_score_range(min_score, max_score): Count the number of members within a score range in the leaderboard
  change_score_for(member, delta): Change the score for a member by some amount delta (delta could be positive or negative)
  rank_for(member): Retrieve the rank for a given member in the leaderboard
  score_for(member): Retrieve the score for a given member in the leaderboard
  check_member?(member): Check to see whether member is in the leaderboard
  score_and_rank_for(member): Retrieve the score and rank for a member in a single call
  remove_members_in_score_range(min_score, max_score): Remove members from the leaderboard within a score range
  percentile_for(member): Calculate the percentile for a given member
  page_for(member, page_size): Determine the page where a member falls in the leaderboard
  rank_members(members_and_scores): Rank an array of members in the leaderboard where you can call via (member_name, score) or pass in an array of [member_name, score]
  merge_leaderboards(destination, keys, options = {:aggregate => :min}): Merge leaderboards given by keys with this leaderboard into destination
  intersect_leaderboards(destination, keys, options = {:aggregate => :min}): Intersect leaderboards given by keys with this leaderboard into destination

Check the online documentation for more detail on each method.

Performance Metrics

10 million sequential scores insert:

  highscore_lb = Leaderboard.new('highscores')
   => #<Leaderboard:0x0000010205fc50 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://localhost:6379/0 (Redis v2.2.5)>> 

  insert_time = Benchmark.measure do
    1.upto(10000000) do |index|
      highscore_lb.rank_member("member_#{index}", index)
    end
  end
   => 323.070000 148.560000 471.630000 (942.068307)

Average time to request an arbitrary page from the leaderboard:

  requests_to_make = 50000
   => 50000 
  lb_request_time = 0
   => 0 
  1.upto(requests_to_make) do
    lb_request_time += Benchmark.measure do
      highscore_lb.leaders(rand(highscore_lb.total_pages))
    end.total
  end
   => 1 
  p lb_request_time / requests_to_make
  0.001513999999999998
   => 0.001513999999999998 

10 million random scores insert:

  insert_time = Benchmark.measure do
    1.upto(10000000) do |index|
      highscore_lb.rank_member("member_#{index}", rand(50000000))
    end
  end
   => 338.480000 155.200000 493.680000 (2188.702475)

Average time to request an arbitrary page from the leaderboard:

  1.upto(requests_to_make) do
    lb_request_time += Benchmark.measure do
      highscore_lb.leaders(rand(highscore_lb.total_pages))
    end.total
  end
   => 1 
  p lb_request_time / requests_to_make
  0.0014615999999999531
   => 0.0014615999999999531 

Bulk insert performance

Ranking individual members:

insert_time = Benchmark.measure do
  1.upto(1000000) do |index|
    highscore_lb.rank_member("member_#{index}", index)
  end
end
 =>  29.340000  15.050000  44.390000 ( 81.673507)

Ranking multiple members at once:

member_data = []
 => [] 
1.upto(1000000) do |index|
  member_data << "member_#{index}"
  member_data << index
end
 => 1 
insert_time = Benchmark.measure do
  highscore_lb.rank_members(member_data)
end
 =>  22.390000   6.380000  28.770000 ( 31.144027)

Ports

The following ports have been made of the leaderboard gem.

Contributing to leaderboard

  • Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
  • Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
  • Fork the project
  • Start a feature/bugfix branch
  • Commit and push until you are happy with your contribution
  • Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright (c) 2011-2012 David Czarnecki. See LICENSE.txt for further details.