Re: [PATCH crosvm 2/2] sys_util: expand on UnixSeqpacket documentation

Cole Helbling
2020-07-06T16:24:23Z

Alyssa Ross <hi@alyssa.is> writes:

> ---
> sys_util/src/net.rs | 28 +++++++++++++++++++++++++++-
> 1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/sys_util/src/net.rs b/sys_util/src/net.rs
> index 82b4f5bb0..0e1cf6e55 100644
> --- a/sys_util/src/net.rs
> +++ b/sys_util/src/net.rs
> @@ -197,7 +197,9 @@ impl UnixSeqpacket {
> }
> }
>
> - /// Receive data from the socket fd to a given buffer.
> + /// Receive a message from the socket fd to a given buffer. The message will then
> + /// be removed from the socket, whether `buf` was large enough to hold all of it or

"whether or not `buf` was large enough..." sounds better, IMO.

> + /// not.
> ///
> /// # Arguments
> /// * `buf` - A mut reference to the data buffer.
> @@ -205,6 +207,30 @@ impl UnixSeqpacket {
> /// # Returns
> /// * `usize` - The size of bytes read to the buffer.
> ///
> + /// # Examples
> + ///
> + /// ```
> + /// # fn main() -> Result<(), sys_util::Error> {
> + /// # use sys_util::net::UnixSeqpacket;
> + /// let (s1, s2) = UnixSeqpacket::pair()?;
> + /// s1.send(b"First message")?;
> + /// s1.send(b"Second message")?;
> + /// s1.send(b"Third message")?;
> + ///
> + /// let mut buf = [0; 13];
> + /// assert_eq!(s2.recv(&mut buf)?, 13);
> + /// assert_eq!(&buf, b"First message");
> + ///
> + /// // Even reading into a buffer zero bytes long will consume a message.
> + /// assert_eq!(s2.recv(&mut [])?, 0);
> + ///
> + /// let mut buf = [0; 5];
> + /// assert_eq!(s2.recv(&mut buf)?, 5);
> + /// assert_eq!(&buf, b"Third");
> + /// # Ok(())
> + /// # }
> + /// ```
> + ///
> /// # Errors
> /// Returns error when `libc::recv` failed.

Returns *an* error.

> pub fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
> --
> 2.26.2

I love seeing docs expanded :^)

Cole