sendfile middleware: various style cleanups

Favor constants over literal strings for a small garbage
reduction.

1 files changed, 11 insertions, 13 deletions

diff --git a/lib/rainbows/sendfile.rb b/lib/rainbows/sendfile.rb
index 8d9b46e..c2e63be 100644
--- a/lib/rainbows/sendfile.rb
+++ b/lib/rainbows/sendfile.rb
@@ -1,6 +1,4 @@
 # -*- encoding: binary -*-
-module Rainbows
-
 # This middleware handles X-\Sendfile headers generated by applications
 # or middlewares down the stack.  It should be placed at the top
 # (outermost layer) of the middleware stack to avoid having its
@@ -48,42 +46,42 @@ module Rainbows
 #      ]
 #    }
 
-class Sendfile < Struct.new(:app)
-
-  # :stopdoc:
-  HH = Rack::Utils::HeaderHash
-  # :startdoc:
+class Rainbows::Sendfile < Struct.new(:app)
 
   # Body wrapper, this allows us to fall back gracefully to
   # +each+ in case a given concurrency model does not optimize
   # +to_path+ calls.
   class Body < Struct.new(:to_path) # :nodoc: all
+    CONTENT_LENGTH = 'Content-Length'.freeze
 
     def self.new(path, headers)
-      unless headers['Content-Length']
+      unless headers[CONTENT_LENGTH]
         stat = File.stat(path)
-        headers['Content-Length'] = stat.size.to_s if stat.file?
+        headers[CONTENT_LENGTH] = stat.size.to_s if stat.file?
       end
       super(path)
     end
 
     # fallback in case our +to_path+ doesn't get handled for whatever reason
     def each(&block)
+      buf = ''
       File.open(to_path, 'rb') do |fp|
-        buf = ''
         yield buf while fp.read(0x4000, buf)
       end
     end
   end
 
+  # :stopdoc:
+  HH = Rack::Utils::HeaderHash
+  X_SENDFILE = 'X-Sendfile'
+  # :startdoc:
+
   def call(env) # :nodoc:
     status, headers, body = app.call(env)
     headers = HH.new(headers)
-    if path = headers.delete('X-Sendfile')
+    if path = headers.delete(X_SENDFILE)
       body = Body.new(path, headers) unless body.respond_to?(:to_path)
     end
     [ status, headers, body ]
   end
 end
-
-end