socket.io got EIO=4 update!
I thought socket.io has completed its mission, who could have imagined the underlying engine.io could received a v4 update somewhere in June? (EIO=4)
In v4, the standard WebSocket has become the primary transport. One needs not to use polling at all but directly connect with WebSocket, all without those complicated upgrade handshaking. Under v4+WebSocket transport, socket.io effectively becomes an WebSocket wrapper+customized ping/pong mechanism (and wasting one byte in every message dedicated to control frame type).
在v4版，就變成以標準WebSocket為主要連線方式了，可以不經polling而直接用WebSocket連接，不再需要轉折的connection upgrade握手程序。在v4+WebSocket之下socket.io就只是一個封裝了WebSocket+一個自定義的ping/pong機制 (以及每個message浪費1個byte做control frame type)，僅此而已。
And…Some servers upgraded to v4, and somewhat broke my client — the server would refuse the reconnect request in a strange way upon disconnection. I finally couldn’t stand this and fire up the debugger/Visual Studio, and found upgrading to v4 fixes the issue.
And hence, I am also publishing the changes to the C# client library which I thought won’t receive any update.
所以也順道更新了一下還以為不會再更新的C# client library。