qubit_clock/wall/fixed_wall_clock.rs
1// =============================================================================
2// Copyright (c) 2025 - 2026 Haixing Hu.
3//
4// SPDX-License-Identifier: Apache-2.0
5//
6// Licensed under the Apache License, Version 2.0.
7// =============================================================================
8//! Defines an immutable fixed wall clock.
9
10use std::time::SystemTime;
11
12use crate::WallClock;
13
14/// A wall clock that always returns one fixed time.
15#[derive(Debug, Clone, Copy, PartialEq, Eq)]
16pub struct FixedWallClock {
17 /// Immutable wall-clock value returned by every sample.
18 fixed_time: SystemTime,
19}
20
21impl FixedWallClock {
22 /// Creates a clock that always returns `fixed_time`.
23 ///
24 /// # Parameters
25 ///
26 /// * `fixed_time` - Wall-clock value returned by every sample.
27 ///
28 /// # Returns
29 ///
30 /// A wall clock fixed at `fixed_time`.
31 #[must_use]
32 pub const fn new(fixed_time: SystemTime) -> Self {
33 Self { fixed_time }
34 }
35
36 /// Returns the immutable time held by this clock.
37 ///
38 /// # Returns
39 ///
40 /// The configured fixed wall-clock value.
41 #[must_use]
42 pub const fn fixed_time(&self) -> SystemTime {
43 self.fixed_time
44 }
45}
46
47impl WallClock for FixedWallClock {
48 /// Returns the configured fixed wall time.
49 ///
50 /// # Returns
51 ///
52 /// The same fixed value for every call.
53 fn now(&self) -> SystemTime {
54 self.fixed_time
55 }
56}