tier 0.1.17

Rust configuration library for layered TOML, env, and CLI settings
Documentation 
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

use std::collections::{BTreeMap, BTreeSet};

use serde::Serialize;
use serde_json::Value;

use crate::TierPatch;
use crate::error::ConfigError;
use crate::patch::DeferredPatchLayer;
use crate::path::collect_paths;

use super::merge::ensure_root_object;
use super::path::ensure_path_safe_keys;
use super::{SourceKind, SourceTrace};

#[derive(Debug, Clone)]
/// Custom serializable configuration layer.
pub struct Layer {
    pub(super) trace: SourceTrace,
    pub(super) value: Value,
    pub(super) entries: BTreeMap<String, SourceTrace>,
    pub(super) coercible_string_paths: BTreeSet<String>,
    pub(super) indexed_array_paths: BTreeSet<String>,
    pub(super) indexed_array_base_lengths: BTreeMap<String, usize>,
    pub(super) direct_array_paths: BTreeSet<String>,
}

impl Layer {
    /// Creates a custom layer from a serializable value.
    pub fn custom<T>(name: impl Into<String>, value: T) -> Result<Self, ConfigError>
    where
        T: Serialize,
    {
        Self::from_serializable(SourceTrace::new(SourceKind::Custom, name), value)
    }

    pub(super) fn from_serializable<T>(trace: SourceTrace, value: T) -> Result<Self, ConfigError>
    where
        T: Serialize,
    {
        let value = serde_json::to_value(value)?;
        Self::from_value(trace, value)
    }

    pub(super) fn from_value(trace: SourceTrace, value: Value) -> Result<Self, ConfigError> {
        ensure_root_object(&value)?;
        ensure_path_safe_keys(&value, "")?;

        let mut paths = Vec::new();
        collect_paths(&value, "", &mut paths);
        let entries = paths
            .into_iter()
            .map(|path| (path, trace.clone()))
            .collect::<BTreeMap<_, _>>();

        Ok(Self {
            trace,
            value,
            entries,
            coercible_string_paths: BTreeSet::new(),
            indexed_array_paths: BTreeSet::new(),
            indexed_array_base_lengths: BTreeMap::new(),
            direct_array_paths: BTreeSet::new(),
        })
    }

    pub(crate) fn from_parts(
        trace: SourceTrace,
        value: Value,
        entries: BTreeMap<String, SourceTrace>,
        coercible_string_paths: BTreeSet<String>,
        indexed_array_paths: BTreeSet<String>,
        indexed_array_base_lengths: BTreeMap<String, usize>,
        direct_array_paths: BTreeSet<String>,
    ) -> Self {
        Self {
            trace,
            value,
            entries,
            coercible_string_paths,
            indexed_array_paths,
            indexed_array_base_lengths,
            direct_array_paths,
        }
    }

    /// Creates a custom configuration layer from a typed sparse patch.
    ///
    /// This is the typed alternative to manually building a [`Layer`] from a
    /// serializable shadow struct.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// # #[cfg(feature = "derive")] {
    /// # fn main() -> Result<(), tier::ConfigError> {
    /// use tier::{Layer, TierPatch};
    ///
    /// #[derive(Debug, TierPatch, Default)]
    /// struct CliPatch {
    ///     port: Option<u16>,
    /// }
    ///
    /// let _layer = Layer::from_patch("typed-cli", &CliPatch { port: Some(7000) })?;
    /// # Ok(())
    /// # }
    /// # }
    /// ```
    pub fn from_patch<P>(name: impl Into<String>, patch: &P) -> Result<Self, ConfigError>
    where
        P: TierPatch,
    {
        Self::from_patch_with_trace(
            SourceTrace {
                kind: SourceKind::Custom,
                name: name.into(),
                location: None,
            },
            patch,
        )
    }

    pub(crate) fn from_patch_with_trace<P>(
        trace: SourceTrace,
        patch: &P,
    ) -> Result<Self, ConfigError>
    where
        P: TierPatch,
    {
        let mut builder = crate::patch::PatchLayerBuilder::from_trace(trace);
        patch.write_layer(&mut builder, "")?;
        Ok(builder.finish())
    }
}

pub(super) enum PendingCustomLayer {
    Immediate(Layer),
    DeferredPatch(DeferredPatchLayer),
}