tempfile/
util.rs

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

tempfile/
util.rs
