1use std::ffi::{OsStr, OsString};
2use std::path::{Path, PathBuf};
3use std::{io, iter::repeat_with};
4
5use crate::error::IoResultExt;
6
7fn tmpname(prefix: &OsStr, suffix: &OsStr, rand_len: usize) -> OsString {
8 let capacity: usize = prefixusize
9 .len()
10 .saturating_add(suffix.len())
11 .saturating_add(rand_len);
12 let mut buf: OsString = OsString::with_capacity(capacity);
13 buf.push(prefix);
14 let mut char_buf: [u8; 4] = [0u8; 4];
15 for c: char in repeat_with(repeater:fastrand::alphanumeric).take(rand_len) {
16 buf.push(c.encode_utf8(&mut char_buf));
17 }
18 buf.push(suffix);
19 buf
20}
21
22pub fn create_helper<R>(
23 base: &Path,
24 prefix: &OsStr,
25 suffix: &OsStr,
26 random_len: usize,
27 permissions: Option<&std::fs::Permissions>,
28 mut f: impl FnMut(PathBuf, Option<&std::fs::Permissions>) -> io::Result<R>,
29) -> io::Result<R> {
30 let num_retries: u32 = if random_len != 0 {
31 crate::NUM_RETRIES
32 } else {
33 1
34 };
35
36 for _ in 0..num_retries {
37 let path: PathBuf = base.join(path:tmpname(prefix, suffix, rand_len:random_len));
38 return match f(path, permissions) {
39 Err(ref e: &Error) if e.kind() == io::ErrorKind::AlreadyExists && num_retries > 1 => continue,
40 // AddrInUse can happen if we're creating a UNIX domain socket and
41 // the path already exists.
42 Err(ref e: &Error) if e.kind() == io::ErrorKind::AddrInUse && num_retries > 1 => continue,
43 res: Result => res,
44 };
45 }
46
47 ErrResult(io::Error::new(
48 kind:io::ErrorKind::AlreadyExists,
49 error:"too many temporary files exist",
50 ))
51 .with_err_path(|| base)
52}
53