eio_sync_file_range

(PECL eio >= 0.0.1dev)

eio_sync_file_range — Sync a file segment with disk

說(shuō)明

eio_sync_file_range(
    mixed $fd,
    int $offset,
    int $nbytes,
    int $flags,
    int $pri = EIO_PRI_DEFAULT,
    callable $callback = NULL,
    mixed $data = NULL
): resource

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

參數(shù)

fd

File descriptor

offset

The starting byte of the file range to be synchronized

nbytes

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.

flags

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).

pri

請(qǐng)求的優(yōu)先級(jí)：EIO_PRI_DEFAULT，EIO_PRI_MIN，EIO_PRI_MAX 或 null。如果是 null，pri 將設(shè)為 EIO_PRI_DEFAULT。

callback

callback 函數(shù)在請(qǐng)求完成時(shí)被調(diào)用。其應(yīng)匹配一下原型：

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

傳遞給請(qǐng)求的用戶數(shù)據(jù)。

result

針對(duì)請(qǐng)求的結(jié)果的值。通常是相應(yīng)的系統(tǒng)調(diào)用返回的值。

req

可選的請(qǐng)求資源，可被 eio_get_last_error() 之類的函數(shù)使用。

data

Arbitrary variable passed to callback.

返回值

eio_sync_file_range() returns request resource on success, 或者在失敗時(shí)返回 false.