(PECL event >= 1.2.6-beta)
EventBuffer::drain — Removes specified number of bytes from the front of the buffer without copying it anywhere
$len
) : boolBehaves as EventBuffer::read() , except that it does not copy the data: it just removes it from the front of the buffer.
len
The number of bytes to remove from the buffer.
成功时返回 true
, 或者在失败时返回 false
。