bjoernager/rust
bjoernager/rust
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implement review suggestions

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This commit is contained in:
DrMeepster 2021-10-20 20:57:28 -07:00
parent bd8e088bd8
commit 0d8fd23a31
4 changed files with 31 additions and 9 deletions
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16
library/std/src/io/mod.rs
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@ -371,8 +371,9 @@ pub(crate) fn default_read_to_end<R: Read + ?Sized>(r: &mut R, buf: &mut Vec<u8>
}
let mut read_buf = ReadBuf::uninit(buf.spare_capacity_mut());
// SAFETY: These bytes were initalized but not filled in the previous loop
unsafe {
// add back extra initalized bytes, we don't want to reinitalize initalized bytes
read_buf.assume_init(initialized);
}
@ -389,6 +390,8 @@ pub(crate) fn default_read_to_end<R: Read + ?Sized>(r: &mut R, buf: &mut Vec<u8>
// store how much was initialized but not filled
initialized = read_buf.initialized_len() - read_buf.filled_len();
let new_len = read_buf.filled_len() + buf.len();
// SAFETY: ReadBuf's invariants mean this much memory is init
unsafe {
buf.set_len(new_len);
}
@ -2558,11 +2561,17 @@ impl<T: Read> Read for Take<T> {
let prev_filled = buf.filled_len();
if self.limit <= buf.remaining() as u64 {
let extra_init = buf.initialized_len() - buf.filled_len();
let ibuf = unsafe { &mut buf.unfilled_mut()[..self.limit as usize] };
// 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;
let extra_init = cmp::min(limit as usize, buf.initialized_len() - buf.filled_len());
// SAFETY: no uninit data is written to ibuf
let ibuf = unsafe { &mut buf.unfilled_mut()[..limit] };
let mut sliced_buf = ReadBuf::uninit(ibuf);
// SAFETY: extra_init bytes of ibuf are known to be initialized
unsafe {
sliced_buf.assume_init(extra_init);
}
@ -2574,6 +2583,7 @@ impl<T: Read> Read for Take<T> {
// sliced_buf / ibuf must drop here
// SAFETY: new_init bytes of buf's unfilled buffer have been initialized
unsafe {
buf.assume_init(new_init);
}