(PECL event >= 1.2.6-beta)
EventBuffer::copyout — Copies out specified number of bytes from the front of the buffer
&$data
   
   , 
    int
     $max_bytes
   
   )
   Behaves just like
   EventBuffer::read()
   , but does not drain any data from the buffer. I.e. it copies the first
   max_bytes
   bytes from the front of the buffer into
   data
   . If there are fewer than
   max_bytes
   bytes available, the function copies all the bytes there are.
  
data
    Output string.
max_bytes
    The number of bytes to copy.
   Returns the number of bytes copied, or
   -1
   on failure.