eio_sync_file_range

eio_sync_file_range() permits fine control when synchronizing the open file referred to by the file descriptor fd with disk.

File descriptor

The starting byte of the file range to be synchronized

Specifies the length of the range to be synchronized, in bytes. If nbytes is zero, then all bytes from offset through to the end of file are synchronized.

A bit-mask. Can include any of the following values: EIO_SYNC_FILE_RANGE_WAIT_BEFORE, EIO_SYNC_FILE_RANGE_WRITE, EIO_SYNC_FILE_RANGE_WAIT_AFTER. These flags have the same meaning as their SYNC_FILE_RANGE_* counterparts(see SYNC_FILE_RANGE(2) man page).

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 function is called when the request is done. It should match the following prototype:

void callback(mixed $data, int $result[, resource $req]);

Arbitrary variable passed to callback.

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