library/std/src/sys/wasi/ext/io.rs

   1 //! WASI-specific extensions to general I/O primitives
   2
   3 #![deny(unsafe_op_in_unsafe_fn)]
   4 #![unstable(feature = "wasi_ext", issue = "none")]
   5
   6 use crate::fs;
   7 use crate::io;
   8 use crate::net;
   9 use crate::sys;
  10 use crate::sys_common::{AsInner, FromInner, IntoInner};
  11
  12 /// Raw file descriptors.
  13 pub type RawFd = u32;
  14
  15 /// A trait to extract the raw WASI file descriptor from an underlying
  16 /// object.
  17 pub trait AsRawFd {
  18     /// Extracts the raw file descriptor.
  19     ///
  20     /// This method does **not** pass ownership of the raw file descriptor
  21     /// to the caller. The descriptor is only guaranteed to be valid while
  22     /// the original object has not yet been destroyed.
  23     fn as_raw_fd(&self) -> RawFd;
  24 }
  25
  26 /// A trait to express the ability to construct an object from a raw file
  27 /// descriptor.
  28 pub trait FromRawFd {
  29     /// Constructs a new instance of `Self` from the given raw file
  30     /// descriptor.
  31     ///
  32     /// This function **consumes ownership** of the specified file
  33     /// descriptor. The returned object will take responsibility for closing
  34     /// it when the object goes out of scope.
  35     ///
  36     /// This function is also unsafe as the primitives currently returned
  37     /// have the contract that they are the sole owner of the file
  38     /// descriptor they are wrapping. Usage of this function could
  39     /// accidentally allow violating this contract which can cause memory
  40     /// unsafety in code that relies on it being true.
  41     unsafe fn from_raw_fd(fd: RawFd) -> Self;
  42 }
  43
  44 /// A trait to express the ability to consume an object and acquire ownership of
  45 /// its raw file descriptor.
  46 pub trait IntoRawFd {
  47     /// Consumes this object, returning the raw underlying file descriptor.
  48     ///
  49     /// This function **transfers ownership** of the underlying file descriptor
  50     /// to the caller. Callers are then the unique owners of the file descriptor
  51     /// and must close the descriptor once it's no longer needed.
  52     fn into_raw_fd(self) -> RawFd;
  53 }
  54
  55 #[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
  56 impl AsRawFd for RawFd {
  57     fn as_raw_fd(&self) -> RawFd {
  58         *self
  59     }
  60 }
  61 #[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
  62 impl IntoRawFd for RawFd {
  63     fn into_raw_fd(self) -> RawFd {
  64         self
  65     }
  66 }
  67 #[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
  68 impl FromRawFd for RawFd {
  69     unsafe fn from_raw_fd(fd: RawFd) -> RawFd {
  70         fd
  71     }
  72 }
  73
  74 impl AsRawFd for net::TcpStream {
  75     fn as_raw_fd(&self) -> RawFd {
  76         self.as_inner().fd().as_raw()
  77     }
  78 }
  79
  80 impl FromRawFd for net::TcpStream {
  81     unsafe fn from_raw_fd(fd: RawFd) -> net::TcpStream {
  82         net::TcpStream::from_inner(sys::net::TcpStream::from_inner(fd))
  83     }
  84 }
  85
  86 impl IntoRawFd for net::TcpStream {
  87     fn into_raw_fd(self) -> RawFd {
  88         self.into_inner().into_fd().into_raw()
  89     }
  90 }
  91
  92 impl AsRawFd for net::TcpListener {
  93     fn as_raw_fd(&self) -> RawFd {
  94         self.as_inner().fd().as_raw()
  95     }
  96 }
  97
  98 impl FromRawFd for net::TcpListener {
  99     unsafe fn from_raw_fd(fd: RawFd) -> net::TcpListener {
 100         net::TcpListener::from_inner(sys::net::TcpListener::from_inner(fd))
 101     }
 102 }
 103
 104 impl IntoRawFd for net::TcpListener {
 105     fn into_raw_fd(self) -> RawFd {
 106         self.into_inner().into_fd().into_raw()
 107     }
 108 }
 109
 110 impl AsRawFd for net::UdpSocket {
 111     fn as_raw_fd(&self) -> RawFd {
 112         self.as_inner().fd().as_raw()
 113     }
 114 }
 115
 116 impl FromRawFd for net::UdpSocket {
 117     unsafe fn from_raw_fd(fd: RawFd) -> net::UdpSocket {
 118         net::UdpSocket::from_inner(sys::net::UdpSocket::from_inner(fd))
 119     }
 120 }
 121
 122 impl IntoRawFd for net::UdpSocket {
 123     fn into_raw_fd(self) -> RawFd {
 124         self.into_inner().into_fd().into_raw()
 125     }
 126 }
 127
 128 impl AsRawFd for fs::File {
 129     fn as_raw_fd(&self) -> RawFd {
 130         self.as_inner().fd().as_raw()
 131     }
 132 }
 133
 134 impl FromRawFd for fs::File {
 135     unsafe fn from_raw_fd(fd: RawFd) -> fs::File {
 136         fs::File::from_inner(sys::fs::File::from_inner(fd))
 137     }
 138 }
 139
 140 impl IntoRawFd for fs::File {
 141     fn into_raw_fd(self) -> RawFd {
 142         self.into_inner().into_fd().into_raw()
 143     }
 144 }
 145
 146 impl AsRawFd for io::Stdin {
 147     fn as_raw_fd(&self) -> RawFd {
 148         sys::stdio::Stdin.as_raw_fd()
 149     }
 150 }
 151
 152 impl AsRawFd for io::Stdout {
 153     fn as_raw_fd(&self) -> RawFd {
 154         sys::stdio::Stdout.as_raw_fd()
 155     }
 156 }
 157
 158 impl AsRawFd for io::Stderr {
 159     fn as_raw_fd(&self) -> RawFd {
 160         sys::stdio::Stderr.as_raw_fd()
 161     }
 162 }