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1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 use std::env;
12 use std::io::{self, Error, ErrorKind};
13 use std::fs;
14 use std::path::{self, PathBuf, Path};
15 use std::__rand::{thread_rng, Rng};
16
17 /// A wrapper for a path to temporary directory implementing automatic
18 /// scope-based deletion.
19 pub struct TempDir {
20 path: Option<PathBuf>,
21 }
22
23 // How many times should we (re)try finding an unused random name? It should be
24 // enough that an attacker will run out of luck before we run out of patience.
25 const NUM_RETRIES: u32 = 1 << 31;
26 // How many characters should we include in a random file name? It needs to
27 // be enough to dissuade an attacker from trying to preemptively create names
28 // of that length, but not so huge that we unnecessarily drain the random number
29 // generator of entropy.
30 const NUM_RAND_CHARS: usize = 12;
31
32 impl TempDir {
33 /// Attempts to make a temporary directory inside of `tmpdir` whose name
34 /// will have the prefix `prefix`. The directory will be automatically
35 /// deleted once the returned wrapper is destroyed.
36 ///
37 /// If no directory can be created, `Err` is returned.
38 #[allow(deprecated)] // rand usage
39 pub fn new_in<P: AsRef<Path>>(tmpdir: P, prefix: &str)
40 -> io::Result<TempDir> {
41 Self::_new_in(tmpdir.as_ref(), prefix)
42 }
43
44 fn _new_in(tmpdir: &Path, prefix: &str) -> io::Result<TempDir> {
45 let storage;
46 let mut tmpdir = tmpdir;
47 if !tmpdir.is_absolute() {
48 let cur_dir = env::current_dir()?;
49 storage = cur_dir.join(tmpdir);
50 tmpdir = &storage;
51 // return TempDir::new_in(&cur_dir.join(tmpdir), prefix);
52 }
53
54 let mut rng = thread_rng();
55 for _ in 0..NUM_RETRIES {
56 let suffix: String = rng.gen_ascii_chars().take(NUM_RAND_CHARS).collect();
57 let leaf = if !prefix.is_empty() {
58 format!("{}.{}", prefix, suffix)
59 } else {
60 // If we're given an empty string for a prefix, then creating a
61 // directory starting with "." would lead to it being
62 // semi-invisible on some systems.
63 suffix
64 };
65 let path = tmpdir.join(&leaf);
66 match fs::create_dir(&path) {
67 Ok(_) => return Ok(TempDir { path: Some(path) }),
68 Err(ref e) if e.kind() == ErrorKind::AlreadyExists => {}
69 Err(e) => return Err(e)
70 }
71 }
72
73 Err(Error::new(ErrorKind::AlreadyExists,
74 "too many temporary directories already exist"))
75 }
76
77 /// Attempts to make a temporary directory inside of `env::temp_dir()` whose
78 /// name will have the prefix `prefix`. The directory will be automatically
79 /// deleted once the returned wrapper is destroyed.
80 ///
81 /// If no directory can be created, `Err` is returned.
82 pub fn new(prefix: &str) -> io::Result<TempDir> {
83 TempDir::new_in(&env::temp_dir(), prefix)
84 }
85
86 /// Unwrap the wrapped `std::path::Path` from the `TempDir` wrapper.
87 /// This discards the wrapper so that the automatic deletion of the
88 /// temporary directory is prevented.
89 pub fn into_path(mut self) -> PathBuf {
90 self.path.take().unwrap()
91 }
92
93 /// Access the wrapped `std::path::Path` to the temporary directory.
94 pub fn path(&self) -> &path::Path {
95 self.path.as_ref().unwrap()
96 }
97
98 /// Close and remove the temporary directory
99 ///
100 /// Although `TempDir` removes the directory on drop, in the destructor
101 /// any errors are ignored. To detect errors cleaning up the temporary
102 /// directory, call `close` instead.
103 pub fn close(mut self) -> io::Result<()> {
104 self.cleanup_dir()
105 }
106
107 fn cleanup_dir(&mut self) -> io::Result<()> {
108 match self.path {
109 Some(ref p) => fs::remove_dir_all(p),
110 None => Ok(())
111 }
112 }
113 }
114
115 impl Drop for TempDir {
116 fn drop(&mut self) {
117 let _ = self.cleanup_dir();
118 }
119 }
120
121 // the tests for this module need to change the path using change_dir,
122 // and this doesn't play nicely with other tests so these unit tests are located
123 // in src/test/run-pass/tempfile.rs