[PATCH] wbuf: use IO#write directly in Ruby 2.5+ for writev

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

Slowly removing kgio dependencies...
---
 lib/yahns/wbuf.rb | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/yahns/wbuf.rb b/lib/yahns/wbuf.rb
index 3abc5f9..d3552b3 100644
--- a/lib/yahns/wbuf.rb
+++ b/lib/yahns/wbuf.rb
@@ -31,6 +31,7 @@
 class Yahns::Wbuf # :nodoc:
   include Yahns::WbufCommon
   attr_reader :busy
+  IO_WRITEV = RUBY_VERSION.to_r >= 2.5 # IO#write uses writev
 
   def initialize(body, persist)
     @tmpio = nil
@@ -40,9 +41,15 @@ def initialize(body, persist)
     @busy = false
   end
 
-  def wbuf_writev(buf)
-    @tmpio.kgio_writev(buf)
-    buf.inject(0) { |n, s| n += s.size }
+  if IO_WRITEV
+    def wbuf_writev(buf)
+      @tmpio.write(*buf)
+    end
+  else
+    def wbuf_writev(buf)
+      @tmpio.kgio_writev(buf)
+      buf.inject(0) { |n, s| n += s.size }
+    end
   end
 
   def wbuf_write(c, buf)
-- 
EW