Eliminate excess Regexp creation due to capture counting

2 files changed, 26 insertions, 4 deletions

diff --git a/actionpack/lib/action_controller/routing/route.rb b/actionpack/lib/action_controller/routing/route.rb
index 3b2cb28545..a610ec7e84 100644
--- a/actionpack/lib/action_controller/routing/route.rb
+++ b/actionpack/lib/action_controller/routing/route.rb
@@ -219,7 +219,7 @@ module ActionController
           next_capture = 1
           extraction = segments.collect do |segment|
             x = segment.match_extraction(next_capture)
-            next_capture += Regexp.new(segment.regexp_chunk).number_of_captures
+            next_capture += segment.number_of_captures
             x
           end
           extraction.compact
diff --git a/actionpack/lib/action_controller/routing/segments.rb b/actionpack/lib/action_controller/routing/segments.rb
index e5f174ae2c..f6b03edcca 100644
--- a/actionpack/lib/action_controller/routing/segments.rb
+++ b/actionpack/lib/action_controller/routing/segments.rb
@@ -13,6 +13,10 @@ module ActionController
         @is_optional = false
       end
 
+      def number_of_captures
+        Regexp.new(regexp_chunk).number_of_captures
+      end
+
       def extraction_code
         nil
       end
@@ -84,6 +88,10 @@ module ActionController
         optional? ? Regexp.optionalize(chunk) : chunk
       end
 
+      def number_of_captures
+        0
+      end
+
       def build_pattern(pattern)
         escaped = Regexp.escape(value)
         if optional? && ! pattern.empty?
@@ -194,10 +202,16 @@ module ActionController
         end
       end
 
+      def number_of_captures
+        if regexp
+          regexp.number_of_captures + 1
+        else
+          1
+        end
+      end
+
       def build_pattern(pattern)
-        chunk = regexp_chunk
-        chunk = "(#{chunk})" if Regexp.new(chunk).number_of_captures == 0
-        pattern = "#{chunk}#{pattern}"
+        pattern = "#{regexp_chunk}#{pattern}"
         optional? ? Regexp.optionalize(pattern) : pattern
       end
 
@@ -230,6 +244,10 @@ module ActionController
         "(?i-:(#{(regexp || Regexp.union(*possible_names)).source}))"
       end
 
+      def number_of_captures
+        1
+      end
+
       # Don't URI.escape the controller name since it may contain slashes.
       def interpolation_chunk(value_code = local_name)
         "\#{#{value_code}.to_s}"
@@ -275,6 +293,10 @@ module ActionController
         regexp || "(.*)"
       end
 
+      def number_of_captures
+        regexp ? regexp.number_of_captures : 1
+      end
+
       def optionality_implied?
         true
       end