openharmony/third_party_rust_nix
1
0
Fork 0
mirror of https://gitee.com/openharmony/third_party_rust_nix synced 2024-10-06 21:23:38 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

30X performance improvement in with_nix_path by not initializing memory

Browse Source 
Signed-off-by: Alex Saveau <saveau.alexandre@gmail.com>
This commit is contained in:
Alex Saveau 2022-02-02 19:40:50 -08:00
parent 2143ffe90d
commit bb54af538d
No known key found for this signature in database
GPG Key ID: 3F8D5B16EB169D48
2 changed files with 16 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
.gitignore vendored
View File

@ -1,6 +1,7 @@
syntax: glob
Cargo.lock
target
.idea
*.diff
*.rej
*.orig

22
src/lib.rs
View File

@ -163,8 +163,9 @@ pub mod unistd;
use libc::PATH_MAX;
use std::result;
use std::{ptr, result, slice};
use std::ffi::{CStr, OsStr};
use std::mem::MaybeUninit;
use std::os::unix::ffi::OsStrExt;
use std::path::{Path, PathBuf};
@ -260,15 +261,22 @@ impl NixPath for [u8] {
}
fn with_nix_path<T, F>(&self, f: F) -> Result<T>
where F: FnOnce(&CStr) -> T {
let mut buf = [0u8; PATH_MAX as usize];
where
F: FnOnce(&CStr) -> T,
{
if self.len() >= PATH_MAX as usize {
return Err(Errno::ENAMETOOLONG)
return Err(Errno::ENAMETOOLONG);
}
buf[..self.len()].copy_from_slice(self);
match CStr::from_bytes_with_nul(&buf[..=self.len()]) {
let mut buf = MaybeUninit::<[u8; PATH_MAX as usize]>::uninit();
let buf_ptr = buf.as_mut_ptr() as *mut u8;
unsafe {
ptr::copy_nonoverlapping(self.as_ptr(), buf_ptr, self.len());
buf_ptr.add(self.len()).write(0);
}
match CStr::from_bytes_with_nul(unsafe { slice::from_raw_parts(buf_ptr, self.len() + 1) }) {
Ok(s) => Ok(f(s)),
Err(_) => Err(Errno::EINVAL),
}