1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
extern crate random;
use random::Source;
use std::io::{Error, ErrorKind, Result};
use std::ops::Deref;
use std::path::{Path, PathBuf};
use std::{env, fmt, fs};
pub struct Directory {
path: PathBuf,
removed: bool,
}
impl Directory {
#[inline]
pub fn new(prefix: &str) -> Result<Directory> {
Directory::with_parent(env::temp_dir(), prefix)
}
pub fn with_parent<T: AsRef<Path>>(parent: T, prefix: &str) -> Result<Directory> {
const RETRIES: u32 = 1 << 31;
const CHARS: usize = 12;
let parent = parent.as_ref();
if !parent.is_absolute() {
let current = try!(env::current_dir());
return Directory::with_parent(current.join(parent), prefix);
}
let mut source = random::default().seed(random_seed(parent, prefix));
for _ in 0..RETRIES {
let suffix: String = random_string(CHARS, &mut source);
let path = if prefix.is_empty() {
parent.join(&suffix)
} else {
parent.join(&format!("{}.{}", prefix, suffix))
};
match fs::create_dir(&path) {
Ok(_) => return Ok(Directory {
path: path.to_path_buf(),
removed: false,
}),
Err(error) => match error.kind() {
ErrorKind::AlreadyExists => {},
_ => return Err(error),
},
}
}
Err(Error::new(ErrorKind::AlreadyExists, "failed to find a vacant name"))
}
#[inline]
pub fn path(&self) -> &Path {
self.as_ref()
}
#[inline]
pub fn into_path(mut self) -> PathBuf {
self.removed = true;
self.path.clone()
}
#[inline]
pub fn remove(mut self) -> Result<()> {
self.cleanup()
}
fn cleanup(&mut self) -> Result<()> {
if self.removed {
return Ok(());
}
self.removed = true;
fs::remove_dir_all(&self.path)
}
}
impl AsRef<Path> for Directory {
#[inline]
fn as_ref(&self) -> &Path {
&self.path
}
}
impl fmt::Debug for Directory {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
self.path.fmt(formatter)
}
}
impl Deref for Directory {
type Target = Path;
#[inline]
fn deref(&self) -> &Path {
&self.path
}
}
impl Drop for Directory {
#[allow(unused_must_use)]
#[inline]
fn drop(&mut self) {
self.cleanup();
}
}
fn random_seed(_: &Path, _: &str) -> [u64; 2] {
use std::mem::uninitialized as rand;
unsafe { [rand::<u64>() ^ 0x12345678, rand::<u64>() ^ 0x87654321] }
}
fn random_string<S: Source>(length: usize, source: &mut S) -> String {
unsafe { String::from_utf8_unchecked((0..length).map(|_| random_letter(source)).collect()) }
}
fn random_letter<S: Source>(source: &mut S) -> u8 {
b'a' + (source.read::<u64>() % 26) as u8
}
#[cfg(test)]
mod tests {
use std::path::Path;
use super::Directory;
#[test]
fn new() {
use std::fs;
let path = {
let directory = Directory::new("foo").unwrap();
assert!(fs::metadata(directory.path()).is_ok());
directory.path().to_path_buf()
};
assert!(fs::metadata(path).is_err());
}
#[test]
fn deref() {
let directory = Directory::new("bar").unwrap();
work(&directory);
fn work(_: &Path) {
}
}
}