eio_fallocate

(PECL eio >= 0.0.1dev)

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

说明

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

参数

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

请求的优先级：EIO_PRI_DEFAULT，EIO_PRI_MIN，EIO_PRI_MAX 或 null。如果是 null，pri 将设为 EIO_PRI_DEFAULT。

callback

callback 函数在请求完成时被调用。其应匹配一下原型：

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

data: 传递给请求的用户数据。
result: 针对请求的结果的值。通常是相应的系统调用返回的值。
req: 可选的请求资源，可被 eio_get_last_error() 之类的函数使用。

data

Arbitrary variable passed to callback.

返回值

eio_fallocate() returns request resource on success, 或者在失败时返回 false.