[PATCH] socket/pure_ruby: use `:exception=>false' on Ruby 2.1+

[PATCH] socket/pure_ruby: use `:exception=>false' on Ruby 2.1+

[Eric Wong]

This feature allows us to avoid expensive exceptions when doing
non-blocking I/O without relying on horrible hacks like kgio.
---
 lib/mogilefs/socket/pure_ruby.rb | 87 +++++++++++++++++++++++++++-------------
 1 file changed, 60 insertions(+), 27 deletions(-)

diff --git a/lib/mogilefs/socket/pure_ruby.rb b/lib/mogilefs/socket/pure_ruby.rb
index e74bbef..d57a7c0 100644
--- a/lib/mogilefs/socket/pure_ruby.rb
+++ b/lib/mogilefs/socket/pure_ruby.rb
@@ -27,16 +27,6 @@ class MogileFS::Socket < Socket
     IO.select(nil, [ self ], nil, timeout)
   end unless self.instance_methods.include?(:wait_writable) # Ruby <2.0.0
 
-  def timed_read(len, dst = "", timeout = 5)
-    begin
-      return read_nonblock(len, dst)
-    rescue Errno::EAGAIN
-      wait(timeout) or unreadable_socket!(timeout)
-    rescue EOFError
-      return
-    end while true
-  end
-
   def timed_peek(len, dst, timeout = 5)
     begin
       rc = recv_nonblock(len, Socket::MSG_PEEK)
@@ -47,26 +37,69 @@ class MogileFS::Socket < Socket
       dst.replace("")
       return
     end while true
+  rescue EOFError
+    nil
   end
 
-  def timed_write(buf, timeout = 5)
-    written = 0
-    expect = buf.bytesize
-    begin
-      rc = write_nonblock(buf)
-      return expect if rc == buf.bytesize
-      written += rc
+  # write_nonblock and read_nonblock support `exception: false`
+  if RUBY_VERSION.to_f >= 2.1
+    def timed_read(len, dst = "", timeout = 5)
+      case rc = read_nonblock(len, dst, :exception => false)
+      when String
+        return rc
+      when :wait_readable
+        wait(timeout) or unreadable_socket!(timeout)
+      when nil
+        return
+      end while true
+    rescue EOFError
+      nil
+    end
+
+    def timed_write(buf, timeout = 5)
+      written = 0
+      expect = buf.bytesize
+      case rc = write_nonblock(buf, :exception => false)
+      when Integer
+        return expect if rc == buf.bytesize
+        written += rc
+        buf = buf.byteslice(rc, buf.bytesize) # Ruby 1.9.3+
+      when :wait_writable
+        wait_writable(timeout) or request_truncated!(written, expect, timeout)
+      end while true
+    end
+  else # Ruby 1.8.7 - 2.0.0
+    def timed_read(len, dst = "", timeout = 5)
+      begin
+        return read_nonblock(len, dst)
+      rescue Errno::EAGAIN
+        wait(timeout) or unreadable_socket!(timeout)
+      rescue EOFError
+        return
+      end while true
+    rescue EOFError
+      nil
+    end
 
-      if buf.respond_to?(:byteslice)
-        buf = buf.byteslice(rc, buf.bytesize)
-      else
-        if buf.respond_to?(:encoding) && buf.encoding != Encoding::BINARY
-          buf = buf.dup.force_encoding(Encoding::BINARY)
+    def timed_write(buf, timeout = 5)
+      written = 0
+      expect = buf.bytesize
+      begin
+        rc = write_nonblock(buf)
+        return expect if rc == buf.bytesize
+        written += rc
+
+        if buf.respond_to?(:byteslice) # Ruby 1.9.3+
+          buf = buf.byteslice(rc, buf.bytesize)
+        else
+          if buf.respond_to?(:encoding) && buf.encoding != Encoding::BINARY
+            buf = buf.dup.force_encoding(Encoding::BINARY)
+          end
+          buf = buf.slice(rc, buf.bytesize)
         end
-        buf = buf.slice(rc, buf.bytesize)
-      end
-    rescue Errno::EAGAIN
-      wait_writable(timeout) or request_truncated!(written, expect, timeout)
-    end while true
+      rescue Errno::EAGAIN
+        wait_writable(timeout) or request_truncated!(written, expect, timeout)
+      end while true
+    end
   end
 end
-- 
EW