eio_readahead

(PECL eio >= 0.0.1dev)

eio_readahead — Perform file readahead into page cache

Beschreibung

eio_readahead ( mixed $fd , int $offset , int $length [, int $pri = EIO_PRI_DEFAULT [, callable $callback = NULL [, mixed $data = NULL ]]] ) : resource

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.

Parameter-Liste

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.

Rückgabewerte

eio_readahead() returns request resource on success or FALSE on error.