Docs : https://pkg.go.dev/github.com/mucz/prependable
Prependable is a buffer that support 'Prepend(data []byte)' method without copying and moving the existing payload inside the buffer.
It is useful when building networking packets, where each protocol adds its own headers to the front of the higher-level protocol header and payload; for example, TCP would prepend its header to the payload, then IP would prepend its own, then ethernet.
The larger the (len(payload)/len(header)), the more Prependable Buffer can show performance benefits.
|- reserved space -|
+-------------------+------------------+------------------+
| prependable bytes | readable bytes | writable bytes |
| | (CONTENT) | |
+-------------------+------------------+------------------+
| | | |
0 <= readerIndex <= writerIndex <= size
