More perf work:

  * Move #set_cookie and #delete_cookie inline to optimize. These optimizations should
    almost certainly be sent back upstream to Rack. The optimization involves using
    an ivar for cookies instead of indexing into the headers each time.
  * Was able to use a bare Hash for headers now that cookies have their own joining
    semantics (some code assumed that the raw cookies were an Array).
  * Cache blankness of body on body=
  * Improve expand_cache_key for Arrays of a single element (common in our case)
  * Use a simple layout condition check unless conditions are used
  * Cache visible actions
  * Lazily load the UrlRewriter
  * Make etag an ivar that is set on prepare!

1 files changed, 15 insertions, 7 deletions

diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 448db538ab..e28df8efa5 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -62,19 +62,27 @@ module ActiveSupport
       end
     end
 
+    RAILS_CACHE_ID   = ENV["RAILS_CACHE_ID"]
+    RAILS_APP_VERION = ENV["RAILS_APP_VERION"]
+    EXPANDED_CACHE   = RAILS_CACHE_ID || RAILS_APP_VERION
+
     def self.expand_cache_key(key, namespace = nil)
       expanded_cache_key = namespace ? "#{namespace}/" : ""
 
-      if ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]
-        expanded_cache_key << "#{ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]}/"
+      if EXPANDED_CACHE
+        expanded_cache_key << "#{RAILS_CACHE_ID || RAILS_APP_VERION}/"
       end
 
-      expanded_cache_key << case
-        when key.respond_to?(:cache_key)
+      expanded_cache_key <<
+        if key.respond_to?(:cache_key)
           key.cache_key
-        when key.is_a?(Array)
-          key.collect { |element| expand_cache_key(element) }.to_param
-        when key
+        elsif key.is_a?(Array)
+          if key.size > 1
+            key.collect { |element| expand_cache_key(element) }.to_param
+          else
+            key.first.to_param
+          end
+        elsif key
           key.to_param
         end.to_s