diff --git a/src/undirected_graph.rs b/src/undirected_graph.rs
index 437b1bc3cb9dff1abc2eed942e9066dc08e7ac69..fd8f81e238d2facedc1ee246a6b936019572740a 100644
--- a/src/undirected_graph.rs
+++ b/src/undirected_graph.rs
@@ -1,4 +1,5 @@
use std::collections::{HashMap, HashSet};
+use union_find::{QuickUnionUf, UnionByRank, UnionFind};
#[derive(Debug, Eq, Hash, PartialEq, Clone)]
pub struct UndirectedGraph {
@@ -6,7 +7,30 @@ pub struct UndirectedGraph {
edges: Vec<(usize, usize)>,
}
+struct EdgeOrbitData {
+ graph: UndirectedGraph,
+ graph_is_odd: bool,
+ compute_edge_orbits: bool,
+ // Union-Find for edge orbits.
+ edge_orbits_uf: QuickUnionUf<UnionByRank>,
+}
+
+impl EdgeOrbitData {
+ pub fn new() -> Self {
+ EdgeOrbitData {
+ graph: UndirectedGraph::new(0, vec![]),
+ graph_is_odd: false,
+ compute_edge_orbits: false,
+ edge_orbits_uf: QuickUnionUf::<UnionByRank>::new(0),
+ }
+ }
+}
+
impl UndirectedGraph {
+ thread_local! {
+ static EDGE_ORBIT_DATA: std::cell::RefCell<EdgeOrbitData> = std::cell::RefCell::new(EdgeOrbitData::new());
+ }
+
pub fn new(num_vertices: usize, edges: Vec<(usize, usize)>) -> Self {
let mut edges_seen: HashSet<(usize, usize)> = HashSet::new();
for (a, b) in &edges {
@@ -78,7 +102,11 @@ impl UndirectedGraph {
fn map_edge(relabel_h_to_g: &[i32], e: &(usize, usize)) -> (usize, usize) {
let a: usize = relabel_h_to_g[e.0] as usize;
let b: usize = relabel_h_to_g[e.1] as usize;
- if a < b { (a, b) } else { (b, a) }
+ if a < b {
+ (a, b)
+ } else {
+ (b, a)
+ }
}
let mapped_edges: Vec<(usize, usize)> = h
.edges
@@ -108,12 +136,8 @@ impl UndirectedGraph {
sign
}
- thread_local! {
- static AUTOMORPHSM_GROUP_GENERATORS: std::cell::RefCell<Vec<Vec<i32>>> = const { std::cell::RefCell::new(vec![]) };
- }
-
#[no_mangle]
- extern "C" fn store_nauty_automorphism(
+ extern "C" fn process_nauty_automorphism(
_count: i32,
perm: *mut i32,
_orbits: *mut i32,
@@ -123,7 +147,37 @@ impl UndirectedGraph {
) {
unsafe {
let automorphism: Vec<i32> = std::slice::from_raw_parts(perm, n as usize).to_vec();
- Self::AUTOMORPHSM_GROUP_GENERATORS.with_borrow_mut(|gens| gens.push(automorphism));
+
+ Self::EDGE_ORBIT_DATA.with_borrow_mut(|edge_orbit_data: &mut EdgeOrbitData| {
+ // NOTE: The automorphisms produced by nauty act on the original graph.
+ let sigma: Vec<i32> = Self::induced_edge_permutation(
+ &edge_orbit_data.graph,
+ &edge_orbit_data.graph,
+ &automorphism,
+ );
+
+ if edge_orbit_data.compute_edge_orbits {
+ // Take powers of sigma and act on edges of graph.
+ let mut tau: Vec<i32> = sigma.clone();
+ let num_edges: i32 = edge_orbit_data.graph.edges.len() as i32;
+ let identity_permutation: Vec<i32> = (0..num_edges).collect();
+ while tau != identity_permutation {
+ for (e, &tau_e) in tau.iter().enumerate() {
+ edge_orbit_data.edge_orbits_uf.union(e, tau_e as usize);
+ }
+ for e in tau.iter_mut() {
+ *e = sigma[*e as usize];
+ }
+ }
+ }
+
+ if Self::permutation_sign(sigma) == -1 {
+ edge_orbit_data.graph_is_odd = true;
+ // NOTE: Giving up computation of edge orbits; we will not use them anyway.
+ edge_orbit_data.compute_edge_orbits = false;
+ // NOTE: There is no way to make nauty cancel the computation here.
+ }
+ });
}
}
@@ -135,7 +189,7 @@ impl UndirectedGraph {
let mut options: nauty_Traces_sys::optionblk = nauty_Traces_sys::optionblk {
getcanon: nauty_Traces_sys::TRUE,
- userautomproc: Some(Self::store_nauty_automorphism),
+ userautomproc: Some(Self::process_nauty_automorphism),
..Default::default()
};
let mut stats: nauty_Traces_sys::statsblk = nauty_Traces_sys::statsblk::default();
@@ -149,7 +203,12 @@ impl UndirectedGraph {
let mut normal_graph: Vec<u64> = vec![0; n];
- Self::AUTOMORPHSM_GROUP_GENERATORS.set(vec![]);
+ Self::EDGE_ORBIT_DATA.set(EdgeOrbitData {
+ graph: self.clone(),
+ graph_is_odd: false,
+ compute_edge_orbits,
+ edge_orbits_uf: QuickUnionUf::<UnionByRank>::new(self.edges.len()),
+ });
unsafe {
nauty_Traces_sys::densenauty(
@@ -186,43 +245,17 @@ impl UndirectedGraph {
let mut sign: i32 = 1;
let mut normal_self_edge_orbits: Vec<usize> = vec![];
- Self::AUTOMORPHSM_GROUP_GENERATORS.with_borrow(|gens| {
- // NOTE: Use Union-Find to compute edge orbits.
- use union_find::{QuickUnionUf, UnionByRank, UnionFind};
- let mut uf: QuickUnionUf<UnionByRank> =
- QuickUnionUf::<UnionByRank>::new(self.edges.len());
-
- for automorphism in gens {
- // NOTE: The automorphisms produced by nauty act on the original graph.
- let sigma: Vec<i32> = Self::induced_edge_permutation(self, self, automorphism);
-
- if compute_edge_orbits {
- // Take powers of sigma and act on edges of self.
- let mut tau: Vec<i32> = sigma.clone();
- let num_edges: i32 = self.edges.len() as i32;
- let identity_permutation: Vec<i32> = (0..num_edges).collect();
- while tau != identity_permutation {
- for (e, &tau_e) in tau.iter().enumerate() {
- uf.union(e, tau_e as usize);
- }
- for e in tau.iter_mut() {
- *e = sigma[*e as usize];
- }
- }
- }
-
- if Self::permutation_sign(sigma) == -1 {
- sign = 0;
- // NOTE: Giving up computation of edge orbits; we will not use them anyway.
- break;
- }
+ Self::EDGE_ORBIT_DATA.with_borrow_mut(|edge_orbit_data: &mut EdgeOrbitData| {
+ if edge_orbit_data.graph_is_odd {
+ sign = 0;
}
-
if sign != 0 {
let edge_permutation: Vec<i32> =
Self::induced_edge_permutation(&normal_self, self, &lab_inv);
- if compute_edge_orbits {
- normal_self_edge_orbits = (0..self.edges.len()).map(|e| uf.find(e)).collect();
+ if edge_orbit_data.compute_edge_orbits {
+ normal_self_edge_orbits = (0..self.edges.len())
+ .map(|e| edge_orbit_data.edge_orbits_uf.find(e))
+ .collect();
// So far these are the edge orbits of self. Finally we apply the isomorphism to get the edge orbits of normal_self.
for e in &mut normal_self_edge_orbits {
*e = edge_permutation[*e] as usize;