use std::fs::{File, OpenOptions};
use std::hash::{Hash, Hasher};
use std::io;
use std::os::unix::fs::MetadataExt;
use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
use std::path::Path;
#[derive(Debug)]
pub struct Handle {
file: Option<File>,
// If is_std is true, then we don't drop the corresponding File since it
// will close the handle.
is_std: bool,
dev: u64,
ino: u64,
}
impl Drop for Handle {
fn drop(&mut self) {
if self.is_std {
// unwrap() will not panic. Since we were able to open an
// std stream successfully, then `file` is guaranteed to be Some()
self.file.take().unwrap().into_raw_fd();
}
}
}
impl Eq for Handle {}
impl PartialEq for Handle {
fn eq(&self, other: &Handle) -> bool {
(self.dev, self.ino) == (other.dev, other.ino)
}
}
impl AsRawFd for crate::Handle {
fn as_raw_fd(&self) -> RawFd {
// unwrap() will not panic. Since we were able to open the
// file successfully, then `file` is guaranteed to be Some()
self.0.file.as_ref().take().unwrap().as_raw_fd()
}
}
impl IntoRawFd for crate::Handle {
fn into_raw_fd(mut self) -> RawFd {
// unwrap() will not panic. Since we were able to open the
// file successfully, then `file` is guaranteed to be Some()
self.0.file.take().unwrap().into_raw_fd()
}
}
impl Hash for Handle {
fn hash<H: Hasher>(&self, state: &mut H) {
self.dev.hash(state);
self.ino.hash(state);
}
}
impl Handle {
pub fn from_path<P: AsRef<Path>>(p: P) -> io::Result<Handle> {
Handle::from_file(OpenOptions::new().read(true).open(p)?)
}
pub fn from_file(file: File) -> io::Result<Handle> {
let md = file.metadata()?;
Ok(Handle {
file: Some(file),
is_std: false,
dev: md.dev(),
ino: md.ino(),
})
}
pub fn from_std(file: File) -> io::Result<Handle> {
Handle::from_file(file).map(|mut h| {
h.is_std = true;
h
})
}
pub fn stdin() -> io::Result<Handle> {
Handle::from_std(unsafe { File::from_raw_fd(0) })
}
pub fn stdout() -> io::Result<Handle> {
Handle::from_std(unsafe { File::from_raw_fd(1) })
}
pub fn stderr() -> io::Result<Handle> {
Handle::from_std(unsafe { File::from_raw_fd(2) })
}
pub fn as_file(&self) -> &File {
// unwrap() will not panic. Since we were able to open the
// file successfully, then `file` is guaranteed to be Some()
self.file.as_ref().take().unwrap()
}
pub fn as_file_mut(&mut self) -> &mut File {
// unwrap() will not panic. Since we were able to open the
// file successfully, then `file` is guaranteed to be Some()
self.file.as_mut().take().unwrap()
}
pub fn dev(&self) -> u64 {
self.dev
}
pub fn ino(&self) -> u64 {
self.ino
}
}
