[PATCH 3/3] http_response: reduce bytecode size

[Eric Wong <e@80x24.org>]

This saves around 200 bytes on x86-64 and potentially improves
CPU cache performance.  This does not reduce inline method
cache overhead as String#<< already has optimized dispatch
support (opt_ltlt in insns.def in Ruby 1.9+)
---
 lib/yahns/http_response.rb | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/yahns/http_response.rb b/lib/yahns/http_response.rb
index f50c9a1..19075bb 100644
--- a/lib/yahns/http_response.rb
+++ b/lib/yahns/http_response.rb
@@ -108,12 +108,12 @@ module Yahns::HttpResponse # :nodoc:
     end
   end
 
-  def kv_str(key, value)
+  def kv_str(buf, key, value)
     if value.include?("\n".freeze)
       # avoiding blank, key-only cookies with /\n+/
-      value.split(/\n+/).map! { |v| "#{key}: #{v}\r\n" }.join
+      value.split(/\n+/).each { |v| buf << "#{key}: #{v}\r\n" }
     else
-      "#{key}: #{value}\r\n"
+      buf << "#{key}: #{value}\r\n"
     end
   end
 
@@ -144,17 +144,17 @@ module Yahns::HttpResponse # :nodoc:
             offset = $1.to_i
             count = $2.to_i - offset + 1
           end
-          buf << kv_str(key, value)
+          kv_str(buf, key, value)
         when %r{\AConnection\z}i
           # allow Rack apps to tell us they want to drop the client
           alive = false if value =~ /\bclose\b/i
         when %r{\AContent-Length\z}i
           flags |= MSG_MORE if have_more?(value)
-          buf << kv_str(key, value)
+          kv_str(buf, key, value)
         when "rack.hijack"
           hijack = value
         else
-          buf << kv_str(key, value)
+          kv_str(buf, key, value)
         end
       end
       buf << (alive ? "Connection: keep-alive\r\n\r\n".freeze
-- 
EW