Skip to content

Use memset to initialize readbuf #102811

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
Oct 12, 2022
Merged

Use memset to initialize readbuf #102811

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
9 changes: 6 additions & 3 deletions library/std/src/io/readbuf.rs
View file
Original file line number Diff line number Diff line change
@@ -3,10 +3,10 @@
#[cfg(test)]
mod tests;

use crate::cmp;
use crate::fmt::{self, Debug, Formatter};
use crate::io::{Result, Write};
use crate::mem::{self, MaybeUninit};
use crate::{cmp, ptr};

/// A borrowed byte buffer which is incrementally filled and initialized.
///
@@ -250,8 +250,11 @@ impl<'a> BorrowedCursor<'a> {
/// Initializes all bytes in the cursor.
#[inline]
pub fn ensure_init(&mut self) -> &mut Self {
for byte in self.uninit_mut() {
byte.write(0);
let uninit = self.uninit_mut();
// SAFETY: 0 is a valid value for MaybeUninit<u8> and the length matches the allocation
// since it is comes from a slice reference.
unsafe {
ptr::write_bytes(uninit.as_mut_ptr(), 0, uninit.len());
}
self.buf.init = self.buf.capacity();