Skip to content

Avoid writes without any data in Write::write_all_vectored #74088

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 27, 2020
Merged

Avoid writes without any data in Write::write_all_vectored #74088

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 5 additions & 2 deletions src/libstd/io/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -251,7 +251,6 @@

use crate::cmp;
use crate::fmt;
use crate::mem;
use crate::memchr;
use crate::ops::{Deref, DerefMut};
use crate::ptr;
Expand Down Expand Up @@ -1435,12 +1434,15 @@ pub trait Write {
/// ```
#[unstable(feature = "write_all_vectored", issue = "70436")]
fn write_all_vectored(&mut self, mut bufs: &mut [IoSlice<'_>]) -> Result<()> {
// Guarantee that bufs is empty if it contains no data,
// to avoid calling write_vectored if there is no data to be written.
bufs = IoSlice::advance(bufs, 0);
while !bufs.is_empty() {
match self.write_vectored(bufs) {
Ok(0) => {
return Err(Error::new(ErrorKind::WriteZero, "failed to write whole buffer"));
}
Ok(n) => bufs = IoSlice::advance(mem::take(&mut bufs), n),
Copy link
Contributor

@Thomasdezeeuw Thomasdezeeuw Jul 8, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It makes me happy this is possible now :)

Ok(n) => bufs = IoSlice::advance(bufs, n),
Err(ref e) if e.kind() == ErrorKind::Interrupted => {}
Err(e) => return Err(e),
}
Expand Down Expand Up @@ -2958,6 +2960,7 @@ mod tests {
#[rustfmt::skip] // Becomes unreadable otherwise.
let tests: Vec<(_, &'static [u8])> = vec![
(vec![], &[]),
(vec![IoSlice::new(&[]), IoSlice::new(&[])], &[]),
(vec![IoSlice::new(&[1])], &[1]),
(vec![IoSlice::new(&[1, 2])], &[1, 2]),
(vec![IoSlice::new(&[1, 2, 3])], &[1, 2, 3]),
Expand Down