honeycomb_core/cmap/components/
betas.rs

1use std::ops::{Index, IndexMut};
2
3use crate::cmap::{LinkError, NULL_DART_ID};
4use crate::stm::{TVar, Transaction, TransactionClosureResult, abort};
5
6use super::identifiers::DartIdType;
7
8/// Beta functions storage.
9///
10/// `N` is the number of beta function stored, including `B0`. This means that, for example,
11/// a 2-map will have a `BetaFunctions<3>` object field.
12pub struct BetaFunctions<const N: usize>(Vec<[TVar<DartIdType>; N]>);
13
14/// Generate beta functions default value for a new dart.
15fn new_beta_entry<const N: usize>() -> [TVar<DartIdType>; N] {
16    (0..N)
17        .map(|_| TVar::new(NULL_DART_ID))
18        .collect::<Vec<_>>()
19        .try_into()
20        .unwrap()
21}
22
23#[allow(unused)]
24impl<const N: usize> BetaFunctions<N> {
25    /// Constructor
26    pub fn new(n_darts: usize) -> Self {
27        Self((0..n_darts).map(|_| new_beta_entry()).collect())
28    }
29
30    /// Extend internal storage capacity
31    pub fn extend(&mut self, len: usize) {
32        self.0.extend((0..len).map(|_| new_beta_entry()));
33    }
34
35    /// Return internal storage capacity
36    pub fn capacity(&self) -> usize {
37        self.0.capacity()
38    }
39}
40
41impl<const N: usize> Index<(u8, DartIdType)> for BetaFunctions<N> {
42    type Output = TVar<DartIdType>;
43
44    fn index(&self, (beta_id, dart_id): (u8, DartIdType)) -> &Self::Output {
45        &self.0[dart_id as usize][beta_id as usize]
46    }
47}
48
49impl<const N: usize> IndexMut<(u8, DartIdType)> for BetaFunctions<N> {
50    fn index_mut(&mut self, (beta_id, dart_id): (u8, DartIdType)) -> &mut Self::Output {
51        &mut self.0[dart_id as usize][beta_id as usize]
52    }
53}
54
55// link methods
56
57// unlink methods
58
59impl<const N: usize> BetaFunctions<N> {
60    /// 1-link operation.
61    ///
62    ///
63    /// This operation corresponds to linking two darts via the *β<sub>1</sub>* function. Unlike
64    /// its sewing counterpart, this method does not contain any code to update the attributes or
65    /// geometrical data of the affected cell(s). The *β<sub>0</sub>* function is also updated.
66    ///
67    /// # Arguments
68    ///
69    /// - `lhs_dart_id: DartIdentifier` -- ID of the first dart to be linked.
70    /// - `rhs_dart_id: DartIdentifier` -- ID of the second dart to be linked.
71    ///
72    /// # Panics
73    ///
74    /// This method may panic if `lhs_dart_id` isn't 1-free or `rhs_dart_id` isn't 0-free.
75    ///
76    pub fn one_link_core(
77        &self,
78        trans: &mut Transaction,
79        lhs_dart_id: DartIdType,
80        rhs_dart_id: DartIdType,
81    ) -> TransactionClosureResult<(), LinkError> {
82        if self[(1, lhs_dart_id)].read(trans)? != NULL_DART_ID {
83            return abort(LinkError::NonFreeBase(1, lhs_dart_id, rhs_dart_id));
84        }
85        if self[(0, rhs_dart_id)].read(trans)? != NULL_DART_ID {
86            return abort(LinkError::NonFreeImage(0, lhs_dart_id, rhs_dart_id));
87        }
88        // set beta_1(lhs_dart) to rhs_dart
89        self[(1, lhs_dart_id)].write(trans, rhs_dart_id)?;
90        // set beta_0(rhs_dart) to lhs_dart
91        self[(0, rhs_dart_id)].write(trans, lhs_dart_id)?;
92        Ok(())
93    }
94
95    /// 2-link operation.
96    ///
97    /// This operation corresponds to linking two darts via the *β<sub>2</sub>* function. Unlike
98    /// its sewing counterpart, this method does not contain any code to update the attributes or
99    /// geometrical data of the affected cell(s).
100    ///
101    /// # Arguments
102    ///
103    /// - `lhs_dart_id: DartIdentifier` -- ID of the first dart to be linked.
104    /// - `rhs_dart_id: DartIdentifier` -- ID of the second dart to be linked.
105    ///
106    /// # Panics
107    ///
108    /// This method may panic if one of `lhs_dart_id` or `rhs_dart_id` isn't 2-free.
109    pub fn two_link_core(
110        &self,
111        trans: &mut Transaction,
112        lhs_dart_id: DartIdType,
113        rhs_dart_id: DartIdType,
114    ) -> TransactionClosureResult<(), LinkError> {
115        if self[(2, lhs_dart_id)].read(trans)? != NULL_DART_ID {
116            return abort(LinkError::NonFreeBase(2, lhs_dart_id, rhs_dart_id));
117        }
118        if self[(2, rhs_dart_id)].read(trans)? != NULL_DART_ID {
119            return abort(LinkError::NonFreeImage(2, lhs_dart_id, rhs_dart_id));
120        }
121        // set beta_2(lhs_dart) to rhs_dart
122        self[(2, lhs_dart_id)].write(trans, rhs_dart_id)?;
123        // set beta_2(rhs_dart) to lhs_dart
124        self[(2, rhs_dart_id)].write(trans, lhs_dart_id)?;
125        Ok(())
126    }
127
128    pub fn three_link_core(
129        &self,
130        trans: &mut Transaction,
131        lhs_dart_id: DartIdType,
132        rhs_dart_id: DartIdType,
133    ) -> TransactionClosureResult<(), LinkError> {
134        if self[(3, lhs_dart_id)].read(trans)? != NULL_DART_ID {
135            return abort(LinkError::NonFreeBase(3, lhs_dart_id, rhs_dart_id));
136        }
137        if self[(3, rhs_dart_id)].read(trans)? != NULL_DART_ID {
138            return abort(LinkError::NonFreeImage(3, lhs_dart_id, rhs_dart_id));
139        }
140        self[(3, lhs_dart_id)].write(trans, rhs_dart_id)?;
141        self[(3, rhs_dart_id)].write(trans, lhs_dart_id)?;
142        Ok(())
143    }
144
145    /// 1-unlink operation.
146    ///
147    /// This operation corresponds to unlinking two darts that are linked via the *β<sub>1</sub>*
148    /// function. Unlike its sewing counterpart, this method does not contain any code to update
149    /// the attributes or geometrical data of the affected cell(s). The *β<sub>0</sub>* function is
150    /// also updated.
151    ///
152    /// # Arguments
153    ///
154    /// - `lhs_dart_id: DartIdentifier` -- ID of the dart to unlink.
155    ///
156    /// # Panics
157    ///
158    /// This method may panic if one of `lhs_dart_id` is already 1-free.
159    pub fn one_unlink_core(
160        &self,
161        trans: &mut Transaction,
162        lhs_dart_id: DartIdType,
163    ) -> TransactionClosureResult<(), LinkError> {
164        // set beta_1(lhs_dart) to NullDart
165        let rhs_dart_id = self[(1, lhs_dart_id)].replace(trans, NULL_DART_ID)?;
166        if rhs_dart_id == NULL_DART_ID {
167            return abort(LinkError::AlreadyFree(1, lhs_dart_id));
168        }
169        // set beta_0(rhs_dart) to NullDart
170        self[(0, rhs_dart_id)].write(trans, NULL_DART_ID)?;
171        Ok(())
172    }
173
174    /// 2-unlink operation.
175    ///
176    /// This operation corresponds to unlinking two darts that are linked via the *β<sub>2</sub>*
177    /// function. Unlike its sewing counterpart, this method does not contain any code to update
178    /// the attributes or geometrical data of the affected cell(s).
179    ///
180    /// # Arguments
181    ///
182    /// - `lhs_dart_id: DartIdentifier` -- ID of the dart to unlink.
183    ///
184    /// # Panics
185    ///
186    /// This method may panic if one of `lhs_dart_id` is already 2-free.
187    pub fn two_unlink_core(
188        &self,
189        trans: &mut Transaction,
190        lhs_dart_id: DartIdType,
191    ) -> TransactionClosureResult<(), LinkError> {
192        // set beta_2(dart) to NullDart
193        let rhs_dart_id = self[(2, lhs_dart_id)].replace(trans, NULL_DART_ID)?;
194        if rhs_dart_id == NULL_DART_ID {
195            return abort(LinkError::AlreadyFree(2, lhs_dart_id));
196        }
197        // set beta_2(beta_2(dart)) to NullDart
198        self[(2, rhs_dart_id)].write(trans, NULL_DART_ID)?;
199        Ok(())
200    }
201
202    pub fn three_unlink_core(
203        &self,
204        trans: &mut Transaction,
205        lhs_dart_id: DartIdType,
206    ) -> TransactionClosureResult<(), LinkError> {
207        // set beta_3(lhs_dart) to NullDart
208        let rhs_dart_id = self[(3, lhs_dart_id)].replace(trans, NULL_DART_ID)?;
209        if rhs_dart_id == NULL_DART_ID {
210            return abort(LinkError::AlreadyFree(3, lhs_dart_id));
211        }
212        // set beta_3(rhs_dart) to NullDart
213        self[(3, rhs_dart_id)].write(trans, NULL_DART_ID)?;
214        Ok(())
215    }
216}
honeycomb_core/cmap/components/betas.rs

honeycomb_core/cmap/components/
betas.rs
