(PECL eio >= 0.0.1dev)
eio_readahead — Perform file readahead into page cache
$fd
, int $offset
, int $length
[, int $pri = EIO_PRI_DEFAULT
[, callable $callback = NULL
[, mixed $data = NULL
]]] )eio_readahead() populates the page cache with data from a file so that subsequent reads from that file will not block on disk I/O. See READAHEAD(2) man page for details.
fd
Stream, Socket resource, or numeric file descriptor
offset
Starting point from which data is to be read.
length
Number of bytes to be read.
pri
The request priority: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or NULL.
If NULL passed, pri internally is set to
EIO_PRI_DEFAULT.
callback
callback function is called when the request is done.
It should match the following prototype:
void callback(mixed $data, int $result[, resource $req]);
data
is custom data passed to the request.
result
request-specific result value; basically, the value returned by corresponding system call.
req
is optional request resource which can be used with functions like eio_get_last_error()
data
Arbitrary variable passed to callback.
eio_readahead() returns request resource on success or FALSE on error.