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diff --git a/_plugins/lib/weightedrandomizer.rb b/_plugins/lib/weightedrandomizer.rb
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+++ b/_plugins/lib/weightedrandomizer.rb
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+# Implements weighted randomization for a group of weighted items.
+# This class expects a hash of key -> value pairs where the value is
+# the weight for the item.
+#
+# @example Usage
+#  wr = WeightedRandomizer.new('queue1' => 25, 'queue2' => 100, 'queue3' => 2)
+#  puts "Using queue #{wr.sample}"
+#
+# @note Mostly adapted from recipe 5.11 from the Ruby Cookbook.
+class WeightedRandomizer
+  VERSION = '0.1.2'
+
+  # Creates a new instance.
+  #
+  # @param [Hash] items the weighted items (key item, value weight)
+  # @return [WeightedRandomizer]
+  def initialize(items)
+    @items = normalize(items)
+  end
+
+  # Returns one or more weighted random values.
+  #
+  # @param [Integer] num the number of samples to return
+  # @return [Object, Array<Object>] one or more sampled items
+  def sample(num = nil)
+    return _sample unless num
+    Array.new(num) { _sample }
+  end
+
+  private
+
+  # Returns a single weighted random value.
+  #
+  # @return [Object] the weighted item
+  def _sample
+    pick = rand
+    @items.each do |key, weight|
+      return key if pick <= weight
+      pick -= weight
+    end
+    nil
+  end
+
+  # Normalizes the weights to float values so that
+  # arbitrary integer/float weights can be specified.
+  #
+  # @param [Hash] items the weighted items (key item, value weight)
+  # @return [Hash] the items with their weights normalized
+  def normalize(items)
+    normalized = {}
+    sum = items.values.inject(0.0, :+)
+    items.each do |key, weight|
+      normalized[key] = weight / sum
+    end
+
+    normalized
+  end
+end
+
+