mas_config/
util.rs

1// Copyright 2024, 2025 New Vector Ltd.
2// Copyright 2021-2024 The Matrix.org Foundation C.I.C.
3//
4// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
5// Please see LICENSE files in the repository root for full details.
6
7use figment::Figment;
8use serde::de::DeserializeOwned;
9
10/// Trait implemented by all configuration section to help loading specific part
11/// of the config and generate the sample config.
12pub trait ConfigurationSection: Sized + DeserializeOwned {
13    /// Specify where this section should live relative to the root.
14    const PATH: Option<&'static str> = None;
15
16    /// Validate the configuration section
17    ///
18    /// # Errors
19    ///
20    /// Returns an error if the configuration is invalid
21    fn validate(
22        &self,
23        _figment: &Figment,
24    ) -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
25        Ok(())
26    }
27
28    /// Extract configuration from a Figment instance.
29    ///
30    /// # Errors
31    ///
32    /// Returns an error if the configuration could not be loaded
33    fn extract(
34        figment: &Figment,
35    ) -> Result<Self, Box<dyn std::error::Error + Send + Sync + 'static>> {
36        let this: Self = if let Some(path) = Self::PATH {
37            figment.extract_inner(path)?
38        } else {
39            figment.extract()?
40        };
41
42        this.validate(figment)?;
43        Ok(this)
44    }
45}
46
47/// Extension trait for [`ConfigurationSection`] to allow extracting the
48/// configuration section from a [`Figment`] or return the default value if the
49/// section is not present.
50pub trait ConfigurationSectionExt: ConfigurationSection + Default {
51    /// Extract the configuration section from the given [`Figment`], or return
52    /// the default value if the section is not present.
53    ///
54    /// # Errors
55    ///
56    /// Returns an error if the configuration section is invalid.
57    fn extract_or_default(
58        figment: &Figment,
59    ) -> Result<Self, Box<dyn std::error::Error + Send + Sync + 'static>> {
60        let this: Self = if let Some(path) = Self::PATH {
61            // If the configuration section is not present, we return the default value
62            if !figment.contains(path) {
63                return Ok(Self::default());
64            }
65
66            figment.extract_inner(path)?
67        } else {
68            figment.extract()?
69        };
70
71        this.validate(figment)?;
72        Ok(this)
73    }
74}
75
76impl<T: ConfigurationSection + Default> ConfigurationSectionExt for T {}
mas_config/util.rs

mas_config/
util.rs
