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

use std::fmt::{Display, Formatter};

#[derive(Clone, Copy, Debug, Hash, Eq, PartialEq, serde::Serialize, serde::Deserialize)]
/// How many times should a constructor be invoked?
pub enum Lifecycle {
    /// The constructor for a `Singleton` type is invoked at most once.
    ///
    /// As a consequence, there is at most one instance of `Singleton` types,
    /// stored inside the server's global state.  
    Singleton,
    /// The constructor for a `RequestScoped` type is invoked at most once for every incoming request.
    ///
    /// As a consequence, there is at most one instance of `RequestScoped` types for every incoming
    /// request.
    RequestScoped,
    /// The constructor for a `Transient` type is invoked every single time an instance of the type
    /// is required.
    ///
    /// As a consequence, there can be **multiple** instances of `Transient` types for every
    /// incoming request.
    Transient,
}

impl Display for Lifecycle {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        let s = match self {
            Lifecycle::Singleton => "singleton",
            Lifecycle::RequestScoped => "request-scoped",
            Lifecycle::Transient => "transient",
        };
        write!(f, "{s}")
    }
}