[PATCH] socket_common: improve readability of case statement

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

Due to the release of Ruby 2.4.1 with the necessary fix,
it seems likely that future releases (if any) of the 2.2
and 2.3 series will avoid garbage on IO#write, too.
---
 lib/mogilefs/socket_common.rb | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/lib/mogilefs/socket_common.rb b/lib/mogilefs/socket_common.rb
index ec9249f..53771c8 100644
--- a/lib/mogilefs/socket_common.rb
+++ b/lib/mogilefs/socket_common.rb
@@ -59,16 +59,21 @@ def readpartial(size, buf = "", timeout = 5)
   # Workaround for https://bugs.ruby-lang.org/issues/13085
   # (excessive garbage from IO#write)
   # This regression was introduced in Ruby 2.0 (r34847)
-  # and looks like it will be fixed in Ruby 2.4.1 and Ruby 2.5
+  # and it is fixed in Ruby 2.4.1+
   # backport request: https://bugs.ruby-lang.org/issues/13299
-  rvn = RUBY_VERSION.split('.'.freeze).map(&:to_i) # "2.4.1" => [ 2, 4, 1 ]
   if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ruby' &&
-     rvn[0] >= 2 &&
-     ((rvn[1] == 4 && rvn[2] == 0) || (rvn[1] < 4))
-    def write(buf)
-      # Blocking TCP writes would error out long before one day,
-      # and MogileFS won't allow file creations which take over a day.
-      timed_write(buf, 86400)
+    case RUBY_VERSION
+    when '2.0.0',
+         '2.1.0'..'2.1.9',
+         # we expect 2.2.7 and 2.3.4 to not need this
+         '2.2.0'..'2.2.6',
+         '2.3.0'..'2.3.3',
+         '2.4.0' # 2.4.1 is good!
+      def write(buf)
+        # Blocking TCP writes would error out long before one day,
+        # and MogileFS won't allow file creations which take over a day.
+        timed_write(buf, 86400)
+      end
     end
   end
 end
-- 
EW