moniker/
extended_moniker.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::error::MonikerError;
6use crate::moniker::Moniker;
7use cm_rust::{FidlIntoNative, NativeIntoFidl};
8use core::cmp::Ord;
9use std::fmt;
10
11#[cfg(feature = "serde")]
12use serde::{Deserialize, Serialize};
13
14/// One of:
15/// - A moniker
16/// - A marker representing component manager's realm
17#[cfg_attr(feature = "serde", derive(Deserialize, Serialize), serde(rename_all = "snake_case"))]
18#[derive(Eq, Ord, PartialOrd, PartialEq, Debug, Clone, Hash)]
19pub enum ExtendedMoniker {
20    ComponentInstance(Moniker),
21    ComponentManager,
22}
23
24/// The string representation of ExtendedMoniker::ComponentManager
25pub const EXTENDED_MONIKER_COMPONENT_MANAGER_STR: &'static str = "<component_manager>";
26
27impl ExtendedMoniker {
28    pub fn unwrap_instance_moniker_or<E: std::error::Error>(
29        &self,
30        error: E,
31    ) -> Result<&Moniker, E> {
32        match self {
33            Self::ComponentManager => Err(error),
34            Self::ComponentInstance(moniker) => Ok(moniker),
35        }
36    }
37
38    pub fn has_prefix(&self, other: &Self) -> bool {
39        match (self, other) {
40            (_, Self::ComponentManager) => true,
41            (Self::ComponentManager, Self::ComponentInstance(_)) => false,
42            (Self::ComponentInstance(a), Self::ComponentInstance(b)) => a.has_prefix(b),
43        }
44    }
45
46    pub fn parse_str(rep: &str) -> Result<Self, MonikerError> {
47        if rep == EXTENDED_MONIKER_COMPONENT_MANAGER_STR {
48            Ok(ExtendedMoniker::ComponentManager)
49        } else {
50            Ok(ExtendedMoniker::ComponentInstance(Moniker::parse_str(rep)?))
51        }
52    }
53}
54
55impl TryFrom<&str> for ExtendedMoniker {
56    type Error = MonikerError;
57
58    fn try_from(input: &str) -> Result<Self, MonikerError> {
59        Self::parse_str(input)
60    }
61}
62
63impl std::str::FromStr for ExtendedMoniker {
64    type Err = MonikerError;
65    fn from_str(s: &str) -> Result<Self, Self::Err> {
66        Self::parse_str(s)
67    }
68}
69
70impl fmt::Display for ExtendedMoniker {
71    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
72        match self {
73            Self::ComponentInstance(m) => {
74                write!(f, "{}", m)?;
75            }
76            Self::ComponentManager => {
77                write!(f, "{}", EXTENDED_MONIKER_COMPONENT_MANAGER_STR)?;
78            }
79        }
80        Ok(())
81    }
82}
83
84impl AsRef<str> for ExtendedMoniker {
85    fn as_ref(&self) -> &str {
86        match self {
87            Self::ComponentInstance(m) => m.as_ref(),
88            Self::ComponentManager => EXTENDED_MONIKER_COMPONENT_MANAGER_STR,
89        }
90    }
91}
92
93impl From<Moniker> for ExtendedMoniker {
94    fn from(m: Moniker) -> Self {
95        Self::ComponentInstance(m)
96    }
97}
98
99impl FidlIntoNative<ExtendedMoniker> for String {
100    fn fidl_into_native(self) -> ExtendedMoniker {
101        self.parse().unwrap()
102    }
103}
104
105impl NativeIntoFidl<String> for ExtendedMoniker {
106    fn native_into_fidl(self) -> String {
107        self.to_string()
108    }
109}
110
111#[cfg(test)]
112mod tests {
113    use super::*;
114
115    #[test]
116    fn parse() {
117        assert_eq!(
118            ExtendedMoniker::parse_str(EXTENDED_MONIKER_COMPONENT_MANAGER_STR).unwrap(),
119            ExtendedMoniker::ComponentManager
120        );
121        assert_eq!(
122            ExtendedMoniker::parse_str("/foo/bar").unwrap(),
123            ExtendedMoniker::ComponentInstance(Moniker::parse_str("/foo/bar").unwrap())
124        );
125        assert!(ExtendedMoniker::parse_str("").is_err(), "cannot be empty");
126    }
127
128    #[test]
129    fn has_prefix() {
130        let cm = ExtendedMoniker::ComponentManager;
131        let root = ExtendedMoniker::ComponentInstance(Moniker::root());
132        let a = ExtendedMoniker::ComponentInstance(Moniker::parse_str("a").unwrap());
133        let ab = ExtendedMoniker::ComponentInstance(Moniker::parse_str("a/b").unwrap());
134
135        assert!(cm.has_prefix(&cm));
136        assert!(!cm.has_prefix(&root));
137        assert!(!cm.has_prefix(&a));
138        assert!(!cm.has_prefix(&ab));
139
140        assert!(root.has_prefix(&cm));
141        assert!(root.has_prefix(&root));
142        assert!(!root.has_prefix(&a));
143        assert!(!root.has_prefix(&ab));
144
145        assert!(a.has_prefix(&cm));
146        assert!(a.has_prefix(&root));
147        assert!(a.has_prefix(&a));
148        assert!(!a.has_prefix(&ab));
149
150        assert!(ab.has_prefix(&cm));
151        assert!(ab.has_prefix(&root));
152        assert!(ab.has_prefix(&a));
153        assert!(ab.has_prefix(&ab));
154    }
155
156    #[test]
157    fn to_string_functions() {
158        let cm_moniker =
159            ExtendedMoniker::parse_str(EXTENDED_MONIKER_COMPONENT_MANAGER_STR).unwrap();
160        let foobar_moniker = ExtendedMoniker::parse_str("foo/bar").unwrap();
161        let empty_moniker = ExtendedMoniker::parse_str(".").unwrap();
162
163        assert_eq!(format!("{}", cm_moniker), EXTENDED_MONIKER_COMPONENT_MANAGER_STR.to_string());
164        assert_eq!(cm_moniker.to_string(), EXTENDED_MONIKER_COMPONENT_MANAGER_STR.to_string());
165        assert_eq!(format!("{}", foobar_moniker), "foo/bar".to_string());
166        assert_eq!(foobar_moniker.to_string(), "foo/bar".to_string());
167        assert_eq!(format!("{}", empty_moniker), ".".to_string());
168        assert_eq!(empty_moniker.to_string(), ".".to_string());
169    }
170}
moniker/extended_moniker.rs

moniker/
extended_moniker.rs
