wasi-common 0.9.0

use std::fs;
use std::ops::{Deref, DerefMut};
use std::os::unix::prelude::{AsRawFd, RawFd};
use std::sync::Mutex;
use yanix::dir::Dir;

#[derive(Debug)]
pub(crate) struct OsHandle {
    pub(crate) file: fs::File,
    // In case that this `OsHandle` actually refers to a directory,
    // when the client makes a `fd_readdir` syscall on this descriptor,
    // we will need to cache the `libc::DIR` pointer manually in order
    // to be able to seek on it later. While on Linux, this is handled
    // by the OS, BSD Unixes require the client to do this caching.
    //
    // This comes directly from the BSD man pages on `readdir`:
    //   > Values returned by telldir() are good only for the lifetime
    //   > of the DIR pointer, dirp, from which they are derived.
    //   > If the directory is closed and then reopened, prior values
    //   > returned by telldir() will no longer be valid.
    pub(crate) dir: Option<Mutex<Dir>>,
}

impl From<fs::File> for OsHandle {
    fn from(file: fs::File) -> Self {
        Self { file, dir: None }
    }
}

impl AsRawFd for OsHandle {
    fn as_raw_fd(&self) -> RawFd {
        self.file.as_raw_fd()
    }
}

impl Deref for OsHandle {
    type Target = fs::File;

    fn deref(&self) -> &Self::Target {
        &self.file
    }
}

impl DerefMut for OsHandle {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.file
    }
}