reduce number of calls to redis by using more pipelining where possib…

…le and hmget in place of hget when it makes sense

  - add method members_data_for and members_data_for_in which use hmget to get the metadata for multiple members in a single call to redis
  - add method rankings_for_members_having_scores and rankings_for_members_having_scores_in to pipeline gathering a list of ranks for members
  - make use of those methods in the methods that would benefit

lib/competition_ranking_leaderboard.rb

@@ -67,29 +67,36 @@ def ranked_in_list_in(leaderboard_name, members, options = {})
       end
     end unless leaderboard_options[:members_only]
 
+    included_members = []
+    scores = []
+
     members.each_with_index do |member, index|
       data = {}
       data[@member_key] = member
       unless leaderboard_options[:members_only]
         data[@score_key] = responses[index * 2 + 1].to_f if responses[index * 2 + 1]
+
         if data[@score_key] == nil
           next unless leaderboard_options[:include_missing]
         end
-
-        if @reverse
-          data[@rank_key] = @redis_connection.zcount(leaderboard_name, '-inf', "(#{data[@score_key]}") + 1 rescue nil
-        else
-          data[@rank_key] = @redis_connection.zcount(leaderboard_name, "(#{data[@score_key]}", '+inf') + 1 rescue nil
-        end
       end
 
-      if leaderboard_options[:with_member_data]
-        data[@member_data_key] = member_data_for_in(leaderboard_name, member)
-      end
+      included_members << member
+      scores << data[@score_key]
 
       ranks_for_members << data
     end
 
+    if leaderboard_options[:with_member_data]
+      members_data_for_in(leaderboard_name, included_members).each_with_index do |member_data, index|
+        ranks_for_members[index][@member_data_key] = member_data
+      end
+    end
+
+    rankings_for_members_having_scores_in(leaderboard_name, included_members, scores).each_with_index do |rank, index|
+      ranks_for_members[index][@rank_key] = rank
+    end
+
     case leaderboard_options[:sort_by]
     when :rank
       ranks_for_members = ranks_for_members.sort_by { |member| member[@rank_key] }
@@ -99,4 +106,36 @@ def ranked_in_list_in(leaderboard_name, members, options = {})
 
     ranks_for_members
   end
-end
+
+  # Retrieve a list of the rankings of leaders given their member names and scores
+  #
+  # @param members [Array] Member names.
+  # @param scores [Array] a list of scores for the members, aligned with the member names
+  #
+  # @return a list of the rankings for the passed in members and scores
+
+  def rankings_for_members_having_scores(members, scores)
+    rankings_for_members_in(@leaderboard_name, members, scores)
+  end
+
+  # Retrieve a list of the rankings of leaders given their member names and scores
+  #
+  # @param leaderboard_name [String] Name of the leaderboard.
+  # @param members [Array] Member names.
+  # @param scores [Array] a list of scores for the members, aligned with the member names
+  #
+  # @return a list of the rankings for the passed in members and scores
+
+  def rankings_for_members_having_scores_in(leaderboard_name, members, scores)
+    @redis_connection.multi do |transaction|
+      members.each_with_index do |member, index|
+        if @reverse
+          transaction.zcount(leaderboard_name, '-inf', "(#{scores[index]}")
+        else
+          transaction.zcount(leaderboard_name, "(#{scores[index]}", '+inf')
+        end
+      end
+    end.map{|rank| rank ? rank + 1 : rank}
+  end
+
+end

lib/leaderboard.rb

@@ -219,6 +219,25 @@ def member_data_for_in(leaderboard_name, member)
     @redis_connection.hget(member_data_key(leaderboard_name), member)
   end
 
+  # Retrieve the optional member data for a given member in the named leaderboard.
+  #
+  # @param leaderboard_name [String] Name of the leaderboard.
+  # @param members [Array] Member names.
+  #
+  # @return array of strings of optional member data.
+  def members_data_for_in(leaderboard_name, members)
+    @redis_connection.hmget(member_data_key(leaderboard_name), *members)
+  end
+
+  # Retrieve the optional member data for the given members in the leaderboard.
+  #
+  # @param members [Array] Member names.
+  #
+  # @return array of strings of optional member data.
+  def members_data_for(members)
+    members_data_for_in(@leaderboard_name, members)
+  end
+
   # Update the optional member data for a given member in the leaderboard.
   #
   # @param member [String] Member name.
@@ -964,13 +983,15 @@ def ranked_in_list_in(leaderboard_name, members, options = {})
         data[@score_key] = responses[index * 2 + 1].to_f if responses[index * 2 + 1]
       end
 
-      if leaderboard_options[:with_member_data]
-        data[@member_data_key] = member_data_for_in(leaderboard_name, member)
-      end
-
       ranks_for_members << data
     end
 
+    if leaderboard_options[:with_member_data]
+      members_data_for_in(leaderboard_name, members).each_with_index do |member_data, index|
+        ranks_for_members[index][@member_data_key] = member_data
+      end
+    end
+
     case leaderboard_options[:sort_by]
     when :rank
       ranks_for_members = ranks_for_members.sort_by { |member| member[@rank_key] }

lib/tie_ranking_leaderboard.rb

@@ -249,13 +249,15 @@ def ranked_in_list_in(leaderboard_name, members, options = {})
         end
       end
 
-      if leaderboard_options[:with_member_data]
-        data[@member_data_key] = member_data_for_in(leaderboard_name, member)
-      end
-
       ranks_for_members << data
     end
 
+    if leaderboard_options[:with_member_data]
+      members_data_for_in(leaderboard_name, members).each_with_index do |member_data, index|
+        ranks_for_members[index][@member_data_key] = member_data
+      end
+    end
+
     case leaderboard_options[:sort_by]
     when :rank
       ranks_for_members = ranks_for_members.sort_by { |member| member[@rank_key] }