sys: reveal std::io representation to sys module

This commit adds a `AsInner` trait to `sys_common` and provides
implementations on many `std::io` types. This is a building block for
exposing platform-specific APIs that hook into `std::io` types.

Author: aturon

src/libstd/io/fs.rs

@@ -88,8 +88,8 @@ pub struct File {
     last_nread: int,
 }
 
-impl sys_common::AsFileDesc for File {
-    fn as_fd(&self) -> &fs_imp::FileDesc {
+impl sys_common::AsInner<fs_imp::FileDesc> for File {
+    fn as_inner(&self) -> &fs_imp::FileDesc {
         &self.fd
     }
 }

src/libstd/io/net/pipe.rs

@@ -33,6 +33,8 @@ use sys::pipe::UnixStream as UnixStreamImp;
 use sys::pipe::UnixListener as UnixListenerImp;
 use sys::pipe::UnixAcceptor as UnixAcceptorImp;
 
+use sys_common;
+
 /// A stream which communicates over a named pipe.
 pub struct UnixStream {
     inner: UnixStreamImp,
@@ -145,6 +147,12 @@ impl Writer for UnixStream {
     }
 }
 
+impl sys_common::AsInner<UnixStreamImp> for UnixStream {
+    fn as_inner(&self) -> &UnixStreamImp {
+        &self.inner
+    }
+}
+
 /// A value that can listen for incoming named pipe connection requests.
 pub struct UnixListener {
     /// The internal, opaque runtime Unix listener.
@@ -186,6 +194,12 @@ impl Listener<UnixStream, UnixAcceptor> for UnixListener {
     }
 }
 
+impl sys_common::AsInner<UnixListenerImp> for UnixListener {
+    fn as_inner(&self) -> &UnixListenerImp {
+        &self.inner
+    }
+}
+
 /// A value that can accept named pipe connections, returned from `listen()`.
 pub struct UnixAcceptor {
     /// The internal, opaque runtime Unix acceptor.
@@ -247,6 +261,12 @@ impl Clone for UnixAcceptor {
     }
 }
 
+impl sys_common::AsInner<UnixAcceptorImp> for UnixAcceptor {
+    fn as_inner(&self) -> &UnixAcceptorImp {
+        &self.inner
+    }
+}
+
 #[cfg(test)]
 #[allow(experimental)]
 mod tests {

src/libstd/io/net/tcp.rs

@@ -31,6 +31,8 @@ use sys::tcp::TcpStream as TcpStreamImp;
 use sys::tcp::TcpListener as TcpListenerImp;
 use sys::tcp::TcpAcceptor as TcpAcceptorImp;
 
+use sys_common;
+
 /// A structure which represents a TCP stream between a local socket and a
 /// remote socket.
 ///
@@ -256,6 +258,12 @@ impl Writer for TcpStream {
     }
 }
 
+impl sys_common::AsInner<TcpStreamImp> for TcpStream {
+    fn as_inner(&self) -> &TcpStreamImp {
+        &self.inner
+    }
+}
+
 /// A structure representing a socket server. This listener is used to create a
 /// `TcpAcceptor` which can be used to accept sockets on a local port.
 ///
@@ -325,6 +333,12 @@ impl Listener<TcpStream, TcpAcceptor> for TcpListener {
     }
 }
 
+impl sys_common::AsInner<TcpListenerImp> for TcpListener {
+    fn as_inner(&self) -> &TcpListenerImp {
+        &self.inner
+    }
+}
+
 /// The accepting half of a TCP socket server. This structure is created through
 /// a `TcpListener`'s `listen` method, and this object can be used to accept new
 /// `TcpStream` instances.
@@ -452,6 +466,12 @@ impl Clone for TcpAcceptor {
     }
 }
 
+impl sys_common::AsInner<TcpAcceptorImp> for TcpAcceptor {
+    fn as_inner(&self) -> &TcpAcceptorImp {
+        &self.inner
+    }
+}
+
 #[cfg(test)]
 #[allow(experimental)]
 mod test {

src/libstd/io/net/udp.rs

@@ -21,6 +21,7 @@ use io::{Reader, Writer, IoResult};
 use option::Option;
 use result::{Ok, Err};
 use sys::udp::UdpSocket as UdpSocketImp;
+use sys_common;
 
 /// A User Datagram Protocol socket.
 ///
@@ -184,6 +185,12 @@ impl Clone for UdpSocket {
     }
 }
 
+impl sys_common::AsInner<UdpSocketImp> for UdpSocket {
+    fn as_inner(&self) -> &UdpSocketImp {
+        &self.inner
+    }
+}
+
 /// A type that allows convenient usage of a UDP stream connected to one
 /// address via the `Reader` and `Writer` traits.
 ///

src/libstd/io/pipe.rs

@@ -86,8 +86,8 @@ impl PipeStream {
     }
 }
 
-impl sys_common::AsFileDesc for PipeStream {
-    fn as_fd(&self) -> &sys::fs::FileDesc {
+impl sys_common::AsInner<sys::fs::FileDesc> for PipeStream {
+    fn as_inner(&self) -> &sys::fs::FileDesc {
         &*self.inner
     }
 }

src/libstd/sys/common/mod.rs

@@ -13,7 +13,7 @@
 
 use io::{mod, IoError, IoResult};
 use prelude::*;
-use sys::{last_error, retry, fs};
+use sys::{last_error, retry};
 use c_str::CString;
 use num::Int;
 use path::BytesContainer;
@@ -83,10 +83,9 @@ pub fn keep_going(data: &[u8], f: |*const u8, uint| -> i64) -> i64 {
     return (origamt - amt) as i64;
 }
 
-// traits for extracting representations from
-
-pub trait AsFileDesc {
-    fn as_fd(&self) -> &fs::FileDesc;
+// A trait for extracting representations from std::io types
+pub trait AsInner<Inner> {
+    fn as_inner(&self) -> &Inner;
 }
 
 pub trait ProcessConfig<K: BytesContainer, V: BytesContainer> {

src/libstd/sys/unix/pipe.rs

@@ -133,7 +133,7 @@ impl UnixStream {
         }
     }
 
-    fn fd(&self) -> fd_t { self.inner.fd }
+    pub fn fd(&self) -> fd_t { self.inner.fd }
 
     #[cfg(target_os = "linux")]
     fn lock_nonblocking(&self) {}
@@ -222,7 +222,7 @@ impl UnixListener {
         })
     }
 
-    fn fd(&self) -> fd_t { self.inner.fd }
+    pub fn fd(&self) -> fd_t { self.inner.fd }
 
     pub fn listen(self) -> IoResult<UnixAcceptor> {
         match unsafe { libc::listen(self.fd(), 128) } {
@@ -260,7 +260,7 @@ struct AcceptorInner {
 }
 
 impl UnixAcceptor {
-    fn fd(&self) -> fd_t { self.inner.listener.fd() }
+    pub fn fd(&self) -> fd_t { self.inner.listener.fd() }
 
     pub fn accept(&mut self) -> IoResult<UnixStream> {
         let deadline = if self.deadline == 0 {None} else {Some(self.deadline)};

src/libstd/sys/unix/process.rs

@@ -24,7 +24,7 @@ use hash::Hash;
 use sys::{mod, retry, c, wouldblock, set_nonblocking, ms_to_timeval};
 use sys::fs::FileDesc;
 use sys_common::helper_thread::Helper;
-use sys_common::{AsFileDesc, mkerr_libc, timeout};
+use sys_common::{AsInner, mkerr_libc, timeout};
 
 pub use sys_common::ProcessConfig;
 
@@ -56,7 +56,7 @@ impl Process {
     pub fn spawn<K, V, C, P>(cfg: &C, in_fd: Option<P>,
                               out_fd: Option<P>, err_fd: Option<P>)
                               -> IoResult<Process>
-        where C: ProcessConfig<K, V>, P: AsFileDesc,
+        where C: ProcessConfig<K, V>, P: AsInner<FileDesc>,
               K: BytesContainer + Eq + Hash, V: BytesContainer
     {
         use libc::funcs::posix88::unistd::{fork, dup2, close, chdir, execvp};
@@ -183,7 +183,7 @@ impl Process {
                             libc::open(devnull.as_ptr(), flags, 0)
                         }
                         Some(obj) => {
-                            let fd = obj.as_fd().fd();
+                            let fd = obj.as_inner().fd();
                             // Leak the memory and the file descriptor. We're in the
                             // child now an all our resources are going to be
                             // cleaned up very soon

src/libstd/sys/windows/pipe.rs

@@ -329,7 +329,7 @@ impl UnixStream {
         }
     }
 
-    fn handle(&self) -> libc::HANDLE { self.inner.handle }
+    pub fn handle(&self) -> libc::HANDLE { self.inner.handle }
 
     fn read_closed(&self) -> bool {
         self.inner.read_closed.load(atomic::SeqCst)
@@ -585,6 +585,10 @@ impl UnixListener {
             }),
         })
     }
+
+    pub fn handle(&self) -> libc::HANDLE {
+        self.handle
+    }
 }
 
 impl Drop for UnixListener {
@@ -729,6 +733,10 @@ impl UnixAcceptor {
             Ok(())
         }
     }
+
+    pub fn handle(&self) -> libc::HANDLE {
+        self.event.ref0
+    }
 }
 
 impl Clone for UnixAcceptor {

src/libstd/sys/windows/process.rs

@@ -26,7 +26,7 @@ use sys::fs;
 use sys::{mod, retry, c, wouldblock, set_nonblocking, ms_to_timeval, timer};
 use sys::fs::FileDesc;
 use sys_common::helper_thread::Helper;
-use sys_common::{AsFileDesc, mkerr_libc, timeout};
+use sys_common::{AsInner, mkerr_libc, timeout};
 
 use io::fs::PathExtensions;
 use string::String;
@@ -105,7 +105,7 @@ impl Process {
     pub fn spawn<K, V, C, P>(cfg: &C, in_fd: Option<P>,
                               out_fd: Option<P>, err_fd: Option<P>)
                               -> IoResult<Process>
-        where C: ProcessConfig<K, V>, P: AsFileDesc,
+        where C: ProcessConfig<K, V>, P: AsInner<FileDesc>,
               K: BytesContainer + Eq + Hash, V: BytesContainer
     {
         use libc::types::os::arch::extra::{DWORD, HANDLE, STARTUPINFO};
@@ -195,7 +195,7 @@ impl Process {
                         }
                     }
                     Some(ref fd) => {
-                        let orig = get_osfhandle(fd.as_fd().fd()) as HANDLE;
+                        let orig = get_osfhandle(fd.as_inner().fd()) as HANDLE;
                         if orig == INVALID_HANDLE_VALUE {
                             return Err(super::last_error())
                         }