zbus/
guid.rs

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1use std::{
2    borrow::{Borrow, BorrowMut},
3    convert::{TryFrom, TryInto},
4    fmt,
5    iter::repeat_with,
6    ops::{Deref, DerefMut},
7    str::FromStr,
8    time::{SystemTime, UNIX_EPOCH},
9};
10
11use serde::{Deserialize, Serialize};
12use static_assertions::assert_impl_all;
13use zvariant::Type;
14
15/// A D-Bus server GUID.
16///
17/// See the D-Bus specification [UUIDs chapter] for details.
18///
19/// You can create a `Guid` from an existing string with [`Guid::try_from::<&str>`][TryFrom].
20///
21/// [UUIDs chapter]: https://dbus.freedesktop.org/doc/dbus-specification.html#uuids
22/// [TryFrom]: #impl-TryFrom%3C%26%27_%20str%3E
23#[derive(Clone, Debug, PartialEq, Eq, Hash, Type, Serialize)]
24pub struct Guid(String);
25
26assert_impl_all!(Guid: Send, Sync, Unpin);
27
28impl Guid {
29    /// Generate a D-Bus GUID that can be used with e.g. [`Connection::new_unix_server`].
30    ///
31    /// [`Connection::new_unix_server`]: struct.Connection.html#method.new_unix_server
32    pub fn generate() -> Self {
33        let r: Vec<u32> = repeat_with(rand::random::<u32>).take(3).collect();
34        let r3 = match SystemTime::now().duration_since(UNIX_EPOCH) {
35            Ok(n) => n.as_secs() as u32,
36            Err(_) => rand::random::<u32>(),
37        };
38
39        let s = format!("{:08x}{:08x}{:08x}{:08x}", r[0], r[1], r[2], r3);
40        Self(s)
41    }
42
43    /// Returns a string slice for the GUID.
44    pub fn as_str(&self) -> &str {
45        self.0.as_str()
46    }
47}
48
49impl fmt::Display for Guid {
50    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
51        write!(f, "{}", self.as_str())
52    }
53}
54
55impl TryFrom<&str> for Guid {
56    type Error = crate::Error;
57
58    /// Creates a GUID from a string with 32 hex digits.
59    ///
60    /// Returns `Err(`[`Error::InvalidGUID`]`)` if the provided string is not a well-formed GUID.
61    ///
62    /// [`Error::InvalidGUID`]: enum.Error.html#variant.InvalidGUID
63    fn try_from(value: &str) -> std::result::Result<Self, Self::Error> {
64        if !valid_guid(value) {
65            Err(crate::Error::InvalidGUID)
66        } else {
67            Ok(Guid(value.to_string()))
68        }
69    }
70}
71
72impl TryFrom<String> for Guid {
73    type Error = crate::Error;
74
75    fn try_from(value: String) -> std::result::Result<Self, Self::Error> {
76        if !valid_guid(&value) {
77            Err(crate::Error::InvalidGUID)
78        } else {
79            Ok(Guid(value))
80        }
81    }
82}
83
84impl FromStr for Guid {
85    type Err = crate::Error;
86
87    fn from_str(s: &str) -> Result<Self, Self::Err> {
88        s.try_into()
89    }
90}
91
92impl<'de> Deserialize<'de> for Guid {
93    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
94    where
95        D: serde::Deserializer<'de>,
96    {
97        String::deserialize(deserializer)
98            .and_then(|s| s.try_into().map_err(serde::de::Error::custom))
99    }
100}
101
102fn valid_guid(value: &str) -> bool {
103    value.as_bytes().len() == 32 && value.chars().all(|c| char::is_ascii_hexdigit(&c))
104}
105
106impl From<Guid> for String {
107    fn from(guid: Guid) -> Self {
108        guid.0
109    }
110}
111
112impl Deref for Guid {
113    type Target = str;
114
115    fn deref(&self) -> &Self::Target {
116        self.as_str()
117    }
118}
119
120impl DerefMut for Guid {
121    fn deref_mut(&mut self) -> &mut Self::Target {
122        &mut self.0
123    }
124}
125
126impl AsRef<str> for Guid {
127    fn as_ref(&self) -> &str {
128        self.as_str()
129    }
130}
131
132impl AsMut<str> for Guid {
133    fn as_mut(&mut self) -> &mut str {
134        &mut self.0
135    }
136}
137
138impl Borrow<str> for Guid {
139    fn borrow(&self) -> &str {
140        self.as_str()
141    }
142}
143
144impl BorrowMut<str> for Guid {
145    fn borrow_mut(&mut self) -> &mut str {
146        &mut self.0
147    }
148}
149
150#[cfg(test)]
151mod tests {
152    use crate::Guid;
153    use test_log::test;
154
155    #[test]
156    fn generate() {
157        let u1 = Guid::generate();
158        let u2 = Guid::generate();
159        assert_eq!(u1.as_str().len(), 32);
160        assert_eq!(u2.as_str().len(), 32);
161        assert_ne!(u1, u2);
162        assert_ne!(u1.as_str(), u2.as_str());
163    }
164}
zbus/guid.rs

zbus/
guid.rs
