tempfile/
util.rs

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 = 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
22pub 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}
tempfile/util.rs

tempfile/
util.rs
