Pre-allocate buffers in File::open_buffered and create_buffered · qinheping/verify-rust-std@15d69c9 (original) (raw)
`@@ -10,7 +10,7 @@
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`//! without encountering any runtime bounds checks.
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`use crate::cmp;
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`-
use crate::io::{self, BorrowedBuf, Read};
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use crate::io::{self, BorrowedBuf, ErrorKind, Read};
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`use crate::mem::MaybeUninit;
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`pub struct Buffer {
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`@@ -36,6 +36,16 @@ impl Buffer {
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`Self { buf, pos: 0, filled: 0, initialized: 0 }
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`}
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#[inline]
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pub fn try_with_capacity(capacity: usize) -> io::Result {
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match Box::try_new_uninit_slice(capacity) {
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Ok(buf) => Ok(Self { buf, pos: 0, filled: 0, initialized: 0 }),
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Err(_) => {
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Err(io::const_io_error!(ErrorKind::OutOfMemory, "failed to allocate read buffer"))
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}
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}
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}
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`#[inline]
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`pub fn buffer(&self) -> &[u8] {
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`// SAFETY: self.pos and self.cap are valid, and self.cap => self.pos, and
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