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From: Alyssa Ross <hi@alyssa.is>
To: devel@spectrum-os.org
Cc: Cole Helbling <cole.e.helbling@outlook.com>
Subject: [PATCH crosvm 2/2 v2] sys_util: expand on UnixSeqpacket documentation
Date: Mon,  6 Jul 2020 23:14:02 +0000	[thread overview]
Message-ID: <20200706231401.16999-1-hi@alyssa.is> (raw)
In-Reply-To: <20200706155913.18065-1-hi@alyssa.is>

---
Incorporated Cole's feedback.

 sys_util/src/net.rs | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/sys_util/src/net.rs b/sys_util/src/net.rs
index 82b4f5bb0..8df1743b6 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 or not `buf` was large enough to hold all of
+    /// it.
     ///
     /// # Arguments
     /// * `buf` - A mut reference to the data buffer.
@@ -205,8 +207,32 @@ 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 when `libc::recv` failed.
     pub fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
         // Safe since we make sure the input `count` == `buf.len()` and handle the returned error.
         unsafe {
-- 
2.26.2

  parent reply	other threads:[~2020-07-06 23:15 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-06 15:59 [PATCH crosvm 1/2] sys_util: make UnixSeqpacket::recv use libc::recv Alyssa Ross
2020-07-06 15:59 ` [PATCH crosvm 2/2] sys_util: expand on UnixSeqpacket documentation Alyssa Ross
2020-07-06 16:24   ` Cole Helbling
2020-07-06 23:07     ` Alyssa Ross
2020-07-06 23:14 ` Alyssa Ross [this message]
2020-07-06 23:22   ` [PATCH crosvm 2/2 v2] " Cole Helbling
2020-07-08 17:06 ` [PATCH crosvm 1/2] sys_util: make UnixSeqpacket::recv use libc::recv Cole Helbling

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