1 files changed, 60 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/frequency.rb b/actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/frequency.rb
new file mode 100644
index 0000000000..671258f807
--- /dev/null
+++ b/actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/frequency.rb
@@ -0,0 +1,60 @@
+require 'rack/mount/utils'
+
+module Rack::Mount
+  module Analysis
+    class Frequency #:nodoc:
+      def initialize(*keys)
+        clear
+        keys.each { |key| self << key }
+      end
+
+      def clear
+        @raw_keys = []
+        @key_frequency = Analysis::Histogram.new
+        self
+      end
+
+      def <<(key)
+        raise ArgumentError unless key.is_a?(Hash)
+        @raw_keys << key
+        nil
+      end
+
+      def possible_keys
+        @possible_keys ||= begin
+          @raw_keys.map do |key|
+            key.inject({}) { |requirements, (method, requirement)|
+              process_key(requirements, method, requirement)
+              requirements
+            }
+          end
+        end
+      end
+
+      def process_key(requirements, method, requirement)
+        if requirement.is_a?(Regexp)
+          expression = Utils.parse_regexp(requirement)
+
+          if expression.is_a?(Regin::Expression) && expression.anchored_to_line?
+            expression = Regin::Expression.new(expression.reject { |e| e.is_a?(Regin::Anchor) })
+            return requirements[method] = expression.to_s if expression.literal?
+          end
+        end
+
+        requirements[method] = requirement
+      end
+
+      def report
+        @report ||= begin
+          possible_keys.each { |keys| keys.each_pair { |key, _| @key_frequency << key } }
+          return [] if @key_frequency.count <= 1
+          @key_frequency.keys_in_upper_quartile
+        end
+      end
+
+      def expire!
+        @possible_keys = @report = nil
+      end
+    end
+  end
+end