quack_builder/
scc.rs

1#![allow(clippy::too_many_arguments)]
2use crate::types::{FileDescriptor, MessageIndex};
3use std::cmp::min;
4use std::collections::HashMap;
5
6fn scc(
7    vertices: &[MessageIndex],
8    desc: &FileDescriptor,
9    u: usize,
10    count: &mut isize,
11    low: &mut [isize],
12    disc: &mut [isize],
13    stack: &mut Vec<usize>,
14    sccs: &mut Vec<Vec<usize>>,
15    ids: &HashMap<MessageIndex, usize>,
16) {
17    disc[u] = *count;
18    low[u] = *count;
19    *count += 1;
20    stack.push(u);
21
22    for &v in vertices[u]
23        .get_message(desc)
24        .all_fields()
25        .filter(|f| !f.boxed && !f.frequency.is_repeated())
26        .filter_map(|f| f.typ.message())
27        .filter_map(|m| ids.get(m))
28    {
29        if disc[v] == -1 {
30            scc(vertices, desc, v, count, low, disc, stack, sccs, ids);
31            low[u] = min(low[u], low[v]);
32        } else if stack.contains(&v) {
33            low[u] = min(low[u], disc[v]);
34        }
35    }
36
37    if low[u] == disc[u] {
38        let mut scc = Vec::new();
39        while let Some(w) = stack.pop() {
40            scc.push(w);
41            if w == u {
42                break;
43            }
44        }
45        sccs.push(scc);
46    }
47}
48
49impl FileDescriptor {
50    fn flatten_messages(&self) -> Vec<MessageIndex> {
51        let mut all_msgs = self
52            .messages
53            .iter()
54            .map(|m| m.index.clone())
55            .collect::<Vec<_>>();
56        let mut vertices = Vec::with_capacity(all_msgs.len());
57        while let Some(m) = all_msgs.pop() {
58            all_msgs.extend(m.get_message(self).messages.iter().map(|m| m.index.clone()));
59            vertices.push(m);
60        }
61        vertices
62    }
63
64    pub fn sccs(&self) -> Vec<Vec<MessageIndex>> {
65        let vertices = self.flatten_messages();
66        let ids = vertices
67            .iter()
68            .enumerate()
69            .map(|(i, m)| (m.get_message(self).index.clone(), i))
70            .collect::<HashMap<_, _>>();
71        let mut low = vec![-1; vertices.len()];
72        let mut disc = vec![-1; vertices.len()];
73        let mut stack: Vec<usize> = Vec::new();
74        let mut count = 0isize;
75        let mut sccs: Vec<Vec<usize>> = Vec::new();
76        for u in 0..vertices.len() {
77            if disc[u] == -1 {
78                scc(
79                    &vertices, self, u, &mut count, &mut low, &mut disc, &mut stack, &mut sccs,
80                    &ids,
81                );
82            }
83        }
84        sccs.into_iter()
85            .map(|scc| scc.into_iter().map(|i| vertices[i].clone()).collect())
86            .collect()
87    }
88}
quack_builder/scc.rs

quack_builder/
scc.rs
