Remove StringIO usage in HeaderOut

It's more GC-friendly to just use an array than to repeatedly
append short strings on top of each other.  I also find StringIO
confusing...

3 files changed, 22 insertions, 13 deletions

diff --git a/lib/unicorn/const.rb b/lib/unicorn/const.rb
index 56c3bb4..8cefd2b 100644
--- a/lib/unicorn/const.rb
+++ b/lib/unicorn/const.rb
@@ -101,7 +101,6 @@ module Unicorn
     HEAD="HEAD".freeze
     # ETag is based on the apache standard of hex mtime-size-inode (inode is 0 on win32)
     ETAG_FORMAT="\"%x-%x-%x\"".freeze
-    HEADER_FORMAT="%s: %s\r\n".freeze
     LINE_END="\r\n".freeze
     REMOTE_ADDR="REMOTE_ADDR".freeze
     HTTP_X_FORWARDED_FOR="HTTP_X_FORWARDED_FOR".freeze
diff --git a/lib/unicorn/header_out.rb b/lib/unicorn/header_out.rb
index a4d987c..b0f66b9 100644
--- a/lib/unicorn/header_out.rb
+++ b/lib/unicorn/header_out.rb
@@ -7,14 +7,21 @@ module Unicorn
   # by just doing them twice (which is sometimes needed in HTTP), but that the normal
   # semantics for Hash (where doing an insert replaces) is not there.
   class HeaderOut
-    attr_reader :out
-    attr_accessor :allowed_duplicates
+    ALLOWED_DUPLICATES = {
+      'Set-Cookie' => true,
+      'Set-Cookie2' => true,
+      'Warning' => true,
+      'WWW-Authenticate' => true,
+    }.freeze
 
-    def initialize(out = StringIO.new)
+    def initialize
       @sent = {}
-      @allowed_duplicates = {"Set-Cookie" => true, "Set-Cookie2" => true,
-        "Warning" => true, "WWW-Authenticate" => true}
-      @out = out
+      @out = []
+    end
+
+    def reset!
+      @sent.clear
+      @out.clear
     end
 
     def merge!(hash)
@@ -25,10 +32,15 @@ module Unicorn
 
     # Simply writes "#{key}: #{value}" to an output buffer.
     def[]=(key,value)
-      if not @sent.has_key?(key) or @allowed_duplicates.has_key?(key)
+      if not @sent.has_key?(key) or ALLOWED_DUPLICATES.has_key?(key)
         @sent[key] = true
-        @out.write(Const::HEADER_FORMAT % [key, value])
+        @out << "#{key}: #{value}\r\n"
       end
     end
+
+    def to_s
+      @out.join
+    end
+
   end
 end
diff --git a/lib/unicorn/http_response.rb b/lib/unicorn/http_response.rb
index 5fbc990..c3094cf 100644
--- a/lib/unicorn/http_response.rb
+++ b/lib/unicorn/http_response.rb
@@ -77,8 +77,7 @@ module Unicorn
         raise "You have already sent the request headers."
       else
         # XXX Dubious ( http://mongrel.rubyforge.org/ticket/19 )
-        @header.out.close
-        @header = HeaderOut.new(StringIO.new) 
+        @header.reset!
 
         @body.close
         @body = StringIO.new
@@ -95,8 +94,7 @@ module Unicorn
 
     def send_header
       if not @header_sent
-        @header.out.rewind
-        write(@header.out.read + Const::LINE_END)
+        write("#{@header.to_s}#{Const::LINE_END}")
         @header_sent = true
       end
     end