time_source/
lib.rs

1//! Time source abstraction for obtaining the current time in milliseconds.
2//!
3//! This module defines a `TimeSource` trait and two implementations:
4//! - [`SystemTimeSource`]: system-clock based implementation
5//! - [`MockedTimeSource`]: mock implementation for testing purposes
6//!
7//! # Example
8//!
9//! ```
10//! use time_source::*;
11//! let system_time = SystemTimeSource;
12//! let now = system_time.get_current_time_millis();
13//! println!("Current time: {now} ms since epoch");
14//! ```
15
16use std::time::SystemTime;
17
18/// A trait representing a source of time that can provide the current time in milliseconds.
19pub trait TimeSource {
20	/// Returns the current time in milliseconds since Unix epoch.
21	fn get_current_time_millis(&self) -> u64;
22}
23
24/// A system clock based time source
25pub struct SystemTimeSource;
26
27impl TimeSource for SystemTimeSource {
28	fn get_current_time_millis(&self) -> u64 {
29		u64::try_from(
30			SystemTime::now()
31				.duration_since(SystemTime::UNIX_EPOCH)
32				.expect("Current time is always after unix epoch; qed")
33				.as_millis(),
34		)
35		.expect("Current time in millis should fit in 64 bits")
36	}
37}
38
39#[cfg(feature = "mock")]
40/// A mock implementation of `TimeSource` for testing purposes.
41pub struct MockedTimeSource {
42	/// The mocked current time in milliseconds since Unix epoch
43	///
44	/// This value will be returned on all `get_current_time_millis` calls
45	pub current_time_millis: u64,
46}
47#[cfg(feature = "mock")]
48impl TimeSource for MockedTimeSource {
49	fn get_current_time_millis(&self) -> u64 {
50		self.current_time_millis
51	}
52}
time_source/lib.rs

time_source/
lib.rs
