mapped_file/file/
managed.rs

1//! Represents a managed `RawFd`.
2//! This will `close()` its contained `RawFd` on drop.
3//!
4//! Can be useful for OS operations on file descriptors without leaking open fds.
5use super::*;
6use std::{
7    ops,
8};
9use libc::{
10    dup, dup2,
11    close,
12};
13
14#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
15#[repr(transparent)]
16pub struct ManagedFD(UnmanagedFD);
17
18impl Clone for ManagedFD {
19    fn clone(&self) -> Self {
20	Self(unsafe { UnmanagedFD::new_unchecked( c_try!(dup(self.0.get()) => if |x| x < 0; "dup(): failed to duplicate file descriptor {}", self.0.get()) ) })
21    }
22    fn clone_from(&mut self, source: &Self) {
23	c_try!(dup2(self.0.get(), source.0.get()) => -1; "dup2(): failed to set file descriptor {} to alias {}", self.0.get(), source.0.get());
24    }
25}
26
27impl ManagedFD
28{
29    #[inline] 
30    pub const unsafe fn take_unchecked(fd: RawFd) -> Self
31    {
32	Self(UnmanagedFD::new_unchecked(fd))
33    }
34
35    /// Duplicate a file-descriptor, aliasing the open resource for the lifetime of the returned `ManagedFD`..
36    #[inline]
37    pub fn alias(file: &(impl AsRawFd + ?Sized)) -> io::Result<Self>
38    {
39	let r = unsafe { libc::dup(file.as_raw_fd()) };
40	if let Some(r) = UnmanagedFD::new_raw(r) {
41	    Ok(Self(r))
42	} else {
43	    Err(io::Error::last_os_error())
44	}
45    }
46
47    #[inline] 
48    pub const fn take_raw(fd: RawFd) -> Self
49    {
50	assert!(fd>=0, "Invalid file descriptor");
51	unsafe {
52	    Self::take_unchecked(fd)
53	}
54    }
55
56    #[inline] 
57    pub const fn take(fd: UnmanagedFD) -> Self
58    {
59	Self(fd)
60    }
61
62    #[inline]
63    pub fn detach(self) -> UnmanagedFD
64    {
65	let v = self.0.clone();
66	std::mem::forget(self);
67	v
68    }
69}
70
71impl ops::Drop for ManagedFD
72{
73    fn drop(&mut self) {
74	unsafe {
75	    close(self.0.get());
76	}
77    }
78}
79
80impl AsRawFd for ManagedFD
81{
82    #[inline] 
83    fn as_raw_fd(&self) -> RawFd {
84	self.0.get()
85    }
86}
87
88impl FromRawFd for ManagedFD
89{
90    #[inline] 
91    unsafe fn from_raw_fd(fd: RawFd) -> Self {
92	Self(UnmanagedFD::new_unchecked(fd))
93    }
94}
95
96impl IntoRawFd for ManagedFD
97{
98    #[inline] 
99    fn into_raw_fd(self) -> RawFd {
100	let raw = self.0.get();
101	std::mem::forget(self);
102	raw
103    }
104}
105
106impl From<ManagedFD> for std::fs::File
107{
108    #[inline] 
109    fn from(from: ManagedFD) -> Self
110    {
111	unsafe {
112	    Self::from_raw_fd(from.into_raw_fd())
113	}
114    }
115}
116
117raw::impl_io_for_fd!(ManagedFD => .0.get());
mapped_file/file/managed.rs

mapped_file/file/
managed.rs
