<?php
Swoole\WebSocket\Server->pack (string $data, int $opcode = 1, bool $finish = true, bool $mask = false)
Pack data into a WebSocket Frame.
WebSocket Frame OpCode
WEBSOCKET_OPCODE_TEXT
= 1 : string
WEBSOCKET_OPCODE_BINARY
= 2 : binary
WEBSOCKET_OPCODE_PING
= 3 : ping