Add more accessors for AioCb

CHANGELOG.md

@@ -30,6 +30,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Added socket option variant that enables the timestamp socket
   control message: `nix::sys::socket::sockopt::ReceiveTimestamp`
   ([#663](https://github.com/nix-rust/nix/pull/663))
+- Added more accessor methods for `AioCb`
+  ([#773](https://github.com/nix-rust/nix/pull/773))
 
 ### Changed
 - Renamed existing `ptrace` wrappers to encourage namespacing ([#692](https://github.com/nix-rust/nix/pull/692))

src/sys/aio.rs

@@ -84,6 +84,11 @@ pub struct AioCb<'a> {
 }
 
 impl<'a> AioCb<'a> {
+    /// Returns the underlying file descriptor associated with the `AioCb`
+    pub fn fd(&self) -> RawFd {
+        self.aiocb.aio_fildes
+    }
+
     /// Constructs a new `AioCb` with no associated buffer.
     ///
     /// The resulting `AioCb` structure is suitable for use with `AioCb::fsync`.
@@ -239,6 +244,38 @@ impl<'a> AioCb<'a> {
         })
     }
 
+    /// Returns the `aiocb`'s `LioOpcode` field
+    ///
+    /// If the value cannot be represented as an `LioOpcode`, returns `None`
+    /// instead.
+    pub fn lio_opcode(&self) -> Option<LioOpcode> {
+        match self.aiocb.aio_lio_opcode {
+            libc::LIO_READ => Some(LioOpcode::LIO_READ),
+            libc::LIO_WRITE => Some(LioOpcode::LIO_WRITE),
+            libc::LIO_NOP => Some(LioOpcode::LIO_NOP),
+            _ => None
+        }
+    }
+
+    /// Returns the requested length of the aio operation in bytes
+    ///
+    /// This method returns the *requested* length of the operation.  To get the
+    /// number of bytes actually read or written by a completed operation, use
+    /// `aio_return` instead.
+    pub fn nbytes(&self) -> usize {
+        self.aiocb.aio_nbytes
+    }
+
+    /// Returns the file offset stored in the `AioCb`
+    pub fn offset(&self) -> off_t {
+        self.aiocb.aio_offset
+    }
+
+    /// Returns the priority of the `AioCb`
+    pub fn priority(&self) -> libc::c_int {
+        self.aiocb.aio_reqprio
+    }
+
     /// Asynchronously reads from a file descriptor into a buffer
     pub fn read(&mut self) -> Result<()> {
         assert!(self.mutable, "Can't read into an immutable buffer");
@@ -250,6 +287,11 @@ impl<'a> AioCb<'a> {
         })
     }
 
+    /// Returns the `SigEvent` stored in the `AioCb`
+    pub fn sigevent(&self) -> SigEvent {
+        SigEvent::from(&self.aiocb.aio_sigevent)
+    }
+
     /// Retrieve return status of an asynchronous operation.  Should only be
     /// called once for each `AioCb`, after `AioCb::error` indicates that it has
     /// completed.  The result is the same as for `read`, `write`, of `fsync`.

test/sys/test_aio.rs

@@ -21,6 +21,28 @@ fn poll_aio(mut aiocb: &mut AioCb) -> Result<()> {
     }
 }
 
+#[test]
+fn test_accessors() {
+    let mut rbuf = vec![0; 4];
+    let aiocb = AioCb::from_mut_slice( 1001,
+                           2,   //offset
+                           &mut rbuf,
+                           42,   //priority
+                           SigevNotify::SigevSignal {
+                               signal: Signal::SIGUSR2,
+                               si_value: 99
+                           },
+                           LioOpcode::LIO_NOP);
+    assert_eq!(1001, aiocb.fd());
+    assert_eq!(Some(LioOpcode::LIO_NOP), aiocb.lio_opcode());
+    assert_eq!(4, aiocb.nbytes());
+    assert_eq!(2, aiocb.offset());
+    assert_eq!(42, aiocb.priority());
+    let sev = aiocb.sigevent().sigevent();
+    assert_eq!(Signal::SIGUSR2 as i32, sev.sigev_signo);
+    assert_eq!(99, sev.sigev_value.sival_ptr as i64);
+}
+
 // Tests AioCb.cancel.  We aren't trying to test the OS's implementation, only our
 // bindings.  So it's sufficient to check that AioCb.cancel returned any
 // AioCancelStat value.