1 use std::ffi::{OsStr, OsString};
2 use std::path::{Path, PathBuf};
3 use std::{io, iter::repeat_with};
4
5 use crate::error::IoResultExt;
6
tmpname(prefix: &OsStr, suffix: &OsStr, rand_len: usize) -> OsString7 fn tmpname(prefix: &OsStr, suffix: &OsStr, rand_len: usize) -> OsString {
8 let capacity = prefix
9 .len()
10 .saturating_add(suffix.len())
11 .saturating_add(rand_len);
12 let mut buf = OsString::with_capacity(capacity);
13 buf.push(prefix);
14 let mut char_buf = [0u8; 4];
15 for c in repeat_with(fastrand::alphanumeric).take(rand_len) {
16 buf.push(c.encode_utf8(&mut char_buf));
17 }
18 buf.push(suffix);
19 buf
20 }
21
create_helper<R>( base: &Path, prefix: &OsStr, suffix: &OsStr, random_len: usize, mut f: impl FnMut(PathBuf) -> io::Result<R>, ) -> io::Result<R>22 pub fn create_helper<R>(
23 base: &Path,
24 prefix: &OsStr,
25 suffix: &OsStr,
26 random_len: usize,
27 mut f: impl FnMut(PathBuf) -> io::Result<R>,
28 ) -> io::Result<R> {
29 let num_retries = if random_len != 0 {
30 crate::NUM_RETRIES
31 } else {
32 1
33 };
34
35 for _ in 0..num_retries {
36 let path = base.join(tmpname(prefix, suffix, random_len));
37 return match f(path) {
38 Err(ref e) if e.kind() == io::ErrorKind::AlreadyExists && num_retries > 1 => continue,
39 // AddrInUse can happen if we're creating a UNIX domain socket and
40 // the path already exists.
41 Err(ref e) if e.kind() == io::ErrorKind::AddrInUse && num_retries > 1 => continue,
42 res => res,
43 };
44 }
45
46 Err(io::Error::new(
47 io::ErrorKind::AlreadyExists,
48 "too many temporary files exist",
49 ))
50 .with_err_path(|| base)
51 }
52