use crate::{backend, io};

use backend::fd::AsFd;

use backend::fs::types::Advice;

use core::num::NonZeroU64;

/// `posix_fadvise(fd, offset, len, advice)`—Declares an expected access

/// pattern for a file.

///

/// If `len` is `None`, the advice extends to the end of the file.

///

/// # References

///  - [POSIX]

///  - [Linux]

///  - [FreeBSD]

///

/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/posix_fadvise.html

/// [Linux]: https://man7.org/linux/man-pages/man2/posix_fadvise.2.html

/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=posix_fadvise&sektion=2

#[inline]

#[doc(alias = "posix_fadvise")]

pub fn fadvise<Fd: AsFd>(

    fd: Fd,

    offset: u64,

    len: Option<NonZeroU64>,

    advice: Advice,

) -> io::Result<()> {

    backend::fs::syscalls::fadvise(fd.as_fd(), offset, len, advice)

}