Remove fallback implementation of mask_xor.

Author: ioquatix

lib/protocol/websocket/frame.rb

@@ -90,28 +90,15 @@ def continued?
 			attr_accessor :length
 			attr_accessor :payload
 
-			if IO.const_defined?(:Buffer) && IO::Buffer.respond_to?(:for) && IO::Buffer.method_defined?(:xor!)
-				private def mask_xor(data, mask)
-					buffer = data.dup
-					mask_buffer = IO::Buffer.for(mask)
-					
-					IO::Buffer.for(buffer) do |buffer|
-						buffer.xor!(mask_buffer)
-					end
-					
-					return buffer
-				end
-			else
-				warn "IO::Buffer not available, falling back to slow implementation of mask_xor!"
-				private def mask_xor(data, mask)
-					result = String.new(encoding: Encoding::BINARY)
-						
-					for i in 0...data.bytesize do
-						result << (data.getbyte(i) ^ mask.getbyte(i % 4))
-					end
-					
-					return result
+			private def mask_xor(data, mask)
+				buffer = data.dup
+				mask_buffer = IO::Buffer.for(mask)
+				
+				IO::Buffer.for(buffer) do |buffer|
+					buffer.xor!(mask_buffer)
 				end
+				
+				return buffer
 			end
 
 			def pack(data = "")