Encode create a packet.Packet from the raw bytes slice and then encode to network bytes slice Protocol refs: https://github.com/NetEase/pomelo/wiki/Communication-Protocol -<type>-|--------<length>--------|-<data>- --------|------------------------|-------- 1 byte packet type, 3 bytes packet data length(big end), and data segment.

NewDecoder -- returns a new decoder that used for decode network bytes slice.

Codec constants.

Codec constants.

ErrPacketSizeExcced is the error used for encode/decode.

Decoder -- reads and decodes network data slice.