firefly_meta/
meta.rs

1use serde::{Deserialize, Serialize};
2
3#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
4#[allow(clippy::module_name_repetitions)]
5pub struct Meta<'a> {
6    pub app_id:      &'a str,
7    /// App name is shown in the launcher in the list of apps.
8    pub app_name:    &'a str,
9    pub author_id:   &'a str,
10    pub author_name: &'a str,
11    /// Launcher is the app that starts first when runtime is launched.
12    pub launcher:    bool,
13    /// Let the app to use privileged and dangerous runtime API.
14    pub sudo:        bool,
15    /// The ever-incrementing version number of the app build.
16    /// Used by netplay to ensure both devices running the same version.
17    pub version:     u32,
18}
19
20impl<'a> Meta<'a> {
21    /// Load metadata from bytes generated by [`Meta::encode`].
22    ///
23    /// # Errors
24    ///
25    /// May return an error if the buffer does not contain valid metadata.
26    pub fn decode(s: &'a [u8]) -> Result<Self, postcard::Error> {
27        postcard::from_bytes(s)
28    }
29
30    /// Encode the matadata using the buffer.
31    ///
32    /// The buffer is required to avoid allocations on the crate side.
33    /// Use [`Meta::size`] to calculate the required buffer size.
34    ///
35    /// # Errors
36    ///
37    /// May return an error if the buffer is no big enough.
38    pub fn encode<'b>(&self, buf: &'b mut [u8]) -> Result<&'b mut [u8], postcard::Error> {
39        postcard::to_slice(self, buf)
40    }
41
42    /// Calculate the buffer size required to encode the meta.
43    #[must_use]
44    #[allow(clippy::missing_panics_doc)]
45    pub fn size(&self) -> usize {
46        let flavor = postcard::ser_flavors::Size::default();
47        postcard::serialize_with_flavor(self, flavor).unwrap()
48    }
49}
50
51/// A struct with only a few safe fields from Meta.
52///
53/// It is used to serialize information about an app outside of the app dir.
54/// Since it is outside, it escapes the hash and signature checks
55/// and so it must not store any information that must be verified before use.
56#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
57#[allow(clippy::module_name_repetitions)]
58pub struct ShortMeta<'a> {
59    pub app_id:    &'a str,
60    pub author_id: &'a str,
61}
62
63impl<'a> ShortMeta<'a> {
64    /// Load metadata from bytes generated by [`ShortMeta::encode`].
65    ///
66    /// # Errors
67    ///
68    /// May return an error if the buffer does not contain valid metadata.
69    pub fn decode(s: &'a [u8]) -> Result<Self, postcard::Error> {
70        postcard::from_bytes(s)
71    }
72
73    /// Encode the matadata using the buffer.
74    ///
75    /// The buffer is required to avoid allocations on the crate side.
76    /// Use [`ShortMeta::size`] to calculate the required buffer size.
77    ///
78    /// # Errors
79    ///
80    /// May return an error if the buffer is no big enough.
81    pub fn encode<'b>(&self, buf: &'b mut [u8]) -> Result<&'b mut [u8], postcard::Error> {
82        postcard::to_slice(self, buf)
83    }
84
85    /// Calculate the buffer size required to encode the meta.
86    #[must_use]
87    #[allow(clippy::missing_panics_doc)]
88    pub fn size(&self) -> usize {
89        let flavor = postcard::ser_flavors::Size::default();
90        postcard::serialize_with_flavor(self, flavor).unwrap()
91    }
92}
93
94#[cfg(test)]
95mod tests {
96    use super::*;
97
98    #[test]
99    fn test_roundtrip() {
100        let given = Meta {
101            app_id:      "some-app-id",
102            app_name:    "Some App Name",
103            author_id:   "some-author-id",
104            author_name: "Some Author Name",
105            launcher:    false,
106            sudo:        false,
107            version:     12,
108        };
109        let mut buf = vec![0; given.size()];
110        let raw = given.encode(&mut buf).unwrap();
111        let actual = Meta::decode(raw).unwrap();
112        assert_eq!(given, actual);
113    }
114}
firefly_meta/meta.rs

firefly_meta/
meta.rs
