Use Set for users and groups, for better lookup performance

* Set provides constant over Array's linear lookup time

lib/rollout.rb

@@ -1,6 +1,7 @@
 require "rollout/version"
 require "rollout/legacy"
 require "zlib"
+require 'set'
 
 class Rollout
   class Feature
@@ -14,15 +15,15 @@ def initialize(name, string = nil, opts = {})
       if string
         raw_percentage,raw_users,raw_groups = string.split("|")
         @percentage = raw_percentage.to_i
-        @users = (raw_users || "").split(",").map(&:to_s)
-        @groups = (raw_groups || "").split(",").map(&:to_sym)
+        @users = (raw_users || "").split(",").map(&:to_s).to_set
+        @groups = (raw_groups || "").split(",").map(&:to_sym).to_set
       else
         clear
       end
     end
 
     def serialize
-      "#{@percentage}|#{@users.join(",")}|#{@groups.join(",")}"
+      "#{@percentage}|#{@users.to_a.join(",")}|#{@groups.to_a.join(",")}"
     end
 
     def add_user(user)
@@ -43,8 +44,8 @@ def remove_group(group)
     end
 
     def clear
-      @groups = []
-      @users = []
+      @groups = Set.new
+      @users = Set.new
       @percentage = 0
     end
 

spec/rollout_spec.rb

@@ -51,7 +51,7 @@
     end
 
     it "leaves the other groups active" do
-      expect(@rollout.get(:chat).groups).to eq([:fivesonly])
+      expect(@rollout.get(:chat).groups).to eq [:fivesonly].to_set
     end
   end
 
@@ -169,7 +169,7 @@
     end
 
     it "remains active for other active users" do
-      expect(@rollout.get(:chat).users).to eq(%w(24))
+      expect(@rollout.get(:chat).users).to eq %w(24).to_set
     end
   end
 
@@ -377,14 +377,14 @@
 
     it "returns the feature object" do
       feature = @rollout.get(:chat)
-      expect(feature.groups).to eq([:caretakers, :greeters])
-      expect(feature.percentage).to eq(10)
-      expect(feature.users).to eq(%w(42))
-      expect(feature.to_hash).to eq({
-        :groups => [:caretakers, :greeters],
+      expect(feature.groups).to eq [:caretakers, :greeters].to_set
+      expect(feature.percentage).to eq 10
+      expect(feature.users).to eq %w(42).to_set
+      expect(feature.to_hash).to eq(
+        :groups => [:caretakers, :greeters].to_set,
         :percentage => 10,
-        :users => %w(42)
-      })
+        :users => %w(42).to_set
+      )
 
       feature = @rollout.get(:signup)
       expect(feature.groups).to be_empty
@@ -404,11 +404,11 @@
 
     it "each feature is cleared" do
       features.each do |feature|
-        expect(@rollout.get(feature).to_hash).to eq({
+        expect(@rollout.get(feature).to_hash).to eq(
           :percentage => 0,
-          :users => [],
-          :groups => []
-        })
+          :users => Set.new,
+          :groups => Set.new
+        )
       end
     end
 
@@ -436,8 +436,8 @@
       @legacy.deactivate_all(:chat)
       expect(@rollout.get(:chat).to_hash).to eq({
         :percentage => 12,
-        :users => %w(24 42),
-        :groups => [:dope_people]
+        :users => %w(24 42).to_set,
+        :groups => [:dope_people].to_set
       })
       expect(@redis.get("feature:chat")).not_to be_nil
     end