(PECL event >= 1.2.6-beta)
EventBuffer::expand — Reserves space in buffer
Alters the last chunk of memory in the buffer, or adds a new chunk, such
that the buffer is now large enough to contain
len
bytes without any further allocations.
len
The number of bytes to reserve for the buffer
成功时返回 true
, 或者在失败时返回 false
。