socket_common: improve readability of case statement

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.

1 files 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 @@ module MogileFS::SocketCommon
   # 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