CommonLogger uses HeaderHash to lookup Content-Length

Since HeaderHash is cheaper to use now, encourage its usage
instead of reinventing a way to lookup header values with
an enforced O(n) overhead.

Under best conditions, this can now be done in O(1) time if the
rest of our middleware stack already uses (and passes)
HeaderHash.  This does make things slower if CommonLogger is the
only middleware in the stack, however that's probably not too
common.

Signed-off-by: Joshua Peek <josh@joshpeek.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/lib/rack/commonlogger.rb b/lib/rack/commonlogger.rb
index 880f0fbf..1edc9b83 100644
--- a/lib/rack/commonlogger.rb
+++ b/lib/rack/commonlogger.rb
@@ -16,6 +16,7 @@ module Rack
     def call(env)
       began_at = Time.now
       status, header, body = @app.call(env)
+      header = Utils::HeaderHash.new(header)
       log(env, status, header, began_at)
       [status, header, body]
     end
@@ -41,12 +42,8 @@ module Rack
     end
 
     def extract_content_length(headers)
-      headers.each do |key, value|
-        if key.downcase == 'content-length'
-          return value.to_s == '0' ? '-' : value
-        end
-      end
-      '-'
+      value = headers['Content-Length'] or return '-'
+      value.to_s == '0' ? '-' : value
     end
   end
 end