leaderboard

Leaderboards backed by Redis in Ruby.

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

Build Status

Installation

gem install leaderboard

or in your Gemfile

ruby gem 'leaderboard'

Make sure your redis server is running! Redis configuration is outside the scope of this README, but check out the Redis 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

Be sure to require the leaderboard library:

ruby require 'leaderboard'

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

ruby 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:

ruby 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:

ruby 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:

ruby 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:

ruby 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):

ruby 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:

ruby 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:

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

The rank_member call will also accept an optional parameter, 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. You could use JSON to encode a Hash of member data. Example:

ruby require 'json' highscore_lb.rank_member('84849292', 1, JSON.generate({'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:

```ruby JSON.parse(highscore_lb.member_data_for(‘84849292’)) => “username”=>”member_name”

highscore_lb.update_member_data(‘84849292’, JSON.generate(=> Time.now, ‘username’ => ‘updated_member_name’)) => “OK” JSON.parse(highscore_lb.member_data_for(‘84849292’)) => “last_updated”=>”2012-06-09 09:11:06 -0400”

highscore_lb.remove_member_data(‘84849292’) ```

If you delete the leaderboard, ALL of the member data is deleted as well.

Optional member data notes

If you use optional member data, the use of the remove_members_in_score_range or remove_members_outside_rank methods will leave data around in the member data hash. This is because the internal Redis method, zremrangebyscore, only returns the number of items removed. It does not return the members that it removed.

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

ruby 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:

ruby 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, all_leaders, around_me, members_from_score_range, members_from_rank_range and ranked_in_list. Valid options are:

  • :with_member_data - true or false (default) to return the optional member data.
  • :page_size - An integer value to change the page size for that call.
  • :members_only - true or false (default) to return only the members without their score and rank.
  • :sort_option - Valid values for :sort_option are :none (default), :score and :rank.

You can also use the members and members_in methods as aliases for the leaders and leaders_in methods.

There are also a few convenience methods to be able to retrieve all leaders from a given leaderboard. They are all_leaders and all_leaders_from. You may also use the aliases all_members or all_members_from. Use any of these methods sparingly as all the information in the leaderboard will be returned.

Add more members to your leaderboard:

ruby 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:

ruby 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:

ruby 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}]

Retrieve members from the leaderboard in a given score range:

ruby members = highscore_lb.members_from_score_range(4, 19) => [{: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}]

Retrieve a single member from the leaderboard at a given position:

ruby members = highscore_lb.member_at(4) => {:member=>"member_92", :rank=>4, :score=>92.0}

Retrieve a range of members from the leaderboard within a given rank range:

ruby members = highscore_lb.members_from_rank_range(1, 5) => [{:member=>"member_95", :rank=>1, :score=>95.0}, {:member=>"member_94", :rank=>2, :score=>94.0}, {:member=>"member_93", :rank=>3, :score=>93.0}, {:member=>"member_92", :rank=>4, :score=>92.0}, {:member=>"member_91", :rank=>5, :score=>91.0}]

The option :sort_option is useful for retrieving an arbitrary list of members from a given leaderboard where you would like the data sorted when returned. The follow examples demonstrate its use:

ruby friends = highscore_lb.ranked_in_list(['member_6', 'member_1', 'member_10'], :sort_by => :rank) => [{:member=>"member_10", :rank=>47, :score=>10.0}, {:member=>"member_6", :rank=>51, :score=>6.0}, {:member=>"member_1", :rank=>56, :score=>1.0}]

ruby friends = highscore_lb.ranked_in_list(['member_6', 'member_1', 'member_10'], :sort_by => :score) => [{:member=>"member_1", :rank=>56, :score=>1.0}, {:member=>"member_6", :rank=>51, :score=>6.0}, {:member=>"member_10", :rank=>47, :score=>10.0}]

Conditionally rank a member in the leaderboard

You can pass a lambda to the rank_member_if method to conditionally rank a member in the leaderboard. The lambda is passed the following 5 parameters:

  • member: Member name.
  • current_score: Current score for the member in the leaderboard. May be nil if the member is not currently ranked in the leaderboard.
  • score: Member score.
  • member_data: Optional member data.
  • leaderboard_options: Leaderboard options, e.g. :reverse => Value of reverse option

```ruby highscore_check = lambda do |member, current_score, score, member_data, leaderboard_options| return true if current_score.nil? return true if score > current_score false end

highscore_lb.rank_member_if(highscore_check, ‘david’, 1337) highscore_lb.score_for(‘david’) => 1337.0 highscore_lb.rank_member_if(highscore_check, ‘david’, 1336) highscore_lb.score_for(‘david’) => 1337.0 highscore_lb.rank_member_if(highscore_check, ‘david’, 1338) highscore_lb.score_for(‘david’) => 1338.0 ```

NOTE: Use a lambda and not a proc, otherwise you will get a LocalJumpError as a return statement in the proc will return from the method enclosing the proc.

Ranking multiple members in a leaderboard at once

Insert multiple data items for members and their associated scores:

As a splat:

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

Or as an array:

ruby 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.

Ranking a member across multiple leaderboards

ruby highscore_lb.rank_member_across(['highscores', 'more_highscores'], 'david', 50000, { :member_name => "david" })

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 remove_members_outside_rank(rank): Remove members from the leaderboard outside a given rank percentile_for(member): Calculate the percentile for a given member score_for_percentile(percentile): Calculate the score for a given percentile value in the leaderboard page_for(member, page_size): Determine the page where a member falls in the leaderboard expire_leaderboard(seconds): Expire the leaderboard in a set number of seconds. expire_leaderboard_at(timestamp): Expire the leaderboard at a specific UNIX timestamp. 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:

```ruby 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:

ruby 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:

ruby 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:

ruby 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:

ruby 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:

ruby 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.

Officially supported:

  • CoffeeScript: https://github.com/agoragames/leaderboard-coffeescript
  • Python: https://github.com/agoragames/leaderboard-python
  • Ruby: https://github.com/agoragames/leaderboard

Unofficially supported (they need some feature parity love):

  • Java: https://github.com/agoragames/java-leaderboard
  • PHP: https://github.com/agoragames/php-leaderboard
  • Scala: https://github.com/agoragames/scala-leaderboard

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) 2011-2013 David Czarnecki. See LICENSE.txt for further details.