microcad_core/
hash.rs

1// Copyright © 2025-2026 The µcad authors <info@microcad.xyz>
2// SPDX-License-Identifier: AGPL-3.0-or-later
3
4//! Render hash functionality.
5
6use std::hash::Hasher;
7
8use derive_more::Deref;
9
10/// Render hash type.
11pub type HashId = u64;
12
13pub use rustc_hash::FxHashMap as HashMap;
14pub use rustc_hash::FxHashSet as HashSet;
15
16/// Trait to implement for typed that contain a pre-computed hash value.
17pub trait ComputedHash {
18    /// Return computed hash value.
19    fn computed_hash(&self) -> HashId;
20}
21
22/// Generic wrapper that contains the hashed value.
23#[derive(Deref, Debug, Clone)]
24pub struct Hashed<T: std::hash::Hash> {
25    #[deref]
26    inner: T,
27    hash: HashId,
28}
29
30impl<T: std::hash::Hash> Hashed<T> {
31    /// Create a new wrapper with hashed.
32    pub fn new(inner: T) -> Self {
33        let mut hasher = rustc_hash::FxHasher::default();
34        inner.hash(&mut hasher);
35        Self {
36            inner,
37            hash: hasher.finish(),
38        }
39    }
40
41    /// Transforms the inner value and recalculates the hash for the new value.
42    pub fn map<U: std::hash::Hash, F>(self, f: F) -> Hashed<U>
43    where
44        F: FnOnce(T) -> U,
45    {
46        // Transform the value
47        let new_inner = f(self.inner);
48
49        // Re-hash the new value to ensure the HashId stays in sync
50        Hashed::new(new_inner)
51    }
52
53    /// Return inner value.
54    pub fn value(&self) -> &T {
55        &self.inner
56    }
57}
58
59impl<T: std::hash::Hash> ComputedHash for Hashed<T> {
60    fn computed_hash(&self) -> HashId {
61        self.hash
62    }
63}
microcad_core/hash.rs

microcad_core/
hash.rs
