eio_fallocate

(PECL eio >= 0.0.1dev)

eio_fallocate — Allows the caller to directly manipulate the allocated disk space for a file

說(shuō)明

eio_fallocate(
    mixed $fd,
    int $mode,
    int $offset,
    int $length,
    int $pri = EIO_PRI_DEFAULT,
    callable $callback = NULL,
    mixed $data = NULL
): resource

eio_fallocate() allows the caller to directly manipulate the allocated disk space for the file specified by fd file descriptor for the byte range starting at offset and continuing for length bytes.

注意: File should be opened for writing

EIO_O_CREAT should be logically OR'd with EIO_O_WRONLY, or EIO_O_RDWR

參數(shù)

fd

Stream, Socket resource, or numeric file descriptor, e.g. returned by eio_open().

mode

Currently only one flag is supported for mode: EIO_FALLOC_FL_KEEP_SIZE (the same as POSIX constant FALLOC_FL_KEEP_SIZE).

offset

Specifies start of the byte range.

length

Specifies length the byte range.

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