use std::fs::{File, OpenOptions};
use std::io;
use std::os::unix::prelude::*;
use std::path::Path;
#[derive(Debug)]
pub struct Lock {
_file: File,
}
impl Lock {
pub fn new(p: &Path, wait: bool, create: bool, exclusive: bool) -> io::Result<Lock> {
let file = OpenOptions::new().read(true).write(true).create(create).mode(0o600).open(p)?;
let mut operation = if exclusive { libc::LOCK_EX } else { libc::LOCK_SH };
if !wait {
operation |= libc::LOCK_NB
}
let ret = unsafe { libc::flock(file.as_raw_fd(), operation) };
if ret == -1 { Err(io::Error::last_os_error()) } else { Ok(Lock { _file: file }) }
}
pub fn error_unsupported(err: &io::Error) -> bool {
matches!(err.raw_os_error(), Some(libc::ENOTSUP) | Some(libc::ENOSYS))
}
}