bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Rollup merge of #139069 - a1phyr:better_take, r=joboet

Browse source 
`io::Take`: avoid new `BorrowedBuf` creation in some case

If `self.limit == buf.capacity()`, doing the whole `BorrowedBuf` dance is not necessary.
This commit is contained in:
Matthias Krüger 2025-03-28 21:18:31 +01:00 • committed by GitHub
commit 7c0a14f030
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 4 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

8
library/std/src/io/mod.rs
View file

@ -2989,11 +2989,11 @@ impl<T: Read> Read for Take<T> {
return Ok(());
}
if self.limit <= buf.capacity() as u64 {
// if we just use an as cast to convert, limit may wrap around on a 32 bit target
let limit = cmp::min(self.limit, usize::MAX as u64) as usize;
if self.limit < buf.capacity() as u64 {
// The condition above guarantees that `self.limit` fits in `usize`.
let limit = self.limit as usize;
let extra_init = cmp::min(limit as usize, buf.init_ref().len());
let extra_init = cmp::min(limit, buf.init_ref().len());
// SAFETY: no uninit data is written to ibuf
let ibuf = unsafe { &mut buf.as_mut()[..limit] };