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use crate::pristine::{ChangeId, Edge, Vertex};
mod debug;
mod dfs;
mod output;
pub mod retrieve;
mod tarjan;
pub(crate) use output::*;
pub(crate) use retrieve::*;
#[derive(Debug, Clone)]
pub(crate) struct AliveVertex {
pub vertex: Vertex<ChangeId>,
flags: Flags,
children: usize,
n_children: usize,
index: usize,
lowlink: usize,
pub scc: usize,
}
bitflags! {
struct Flags: u8 {
const ZOMBIE = 4;
const VISITED = 2;
const ONSTACK = 1;
}
}
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
pub(crate) struct VertexId(pub(crate) usize);
impl VertexId {
const DUMMY: VertexId = VertexId(0);
}
impl AliveVertex {
const DUMMY: AliveVertex = AliveVertex {
vertex: Vertex::BOTTOM,
flags: Flags::empty(),
children: 0,
n_children: 0,
index: 0,
lowlink: 0,
scc: 0,
};
}
#[derive(Debug)]
pub struct Graph {
pub(crate) lines: Vec<AliveVertex>,
children: Vec<(Option<Edge>, VertexId)>,
total_bytes: usize,
}
impl Graph {
pub fn len_vertices(&self) -> usize {
self.lines.len()
}
pub fn len_bytes(&self) -> usize {
self.total_bytes
}
}
impl std::ops::Index<VertexId> for Graph {
type Output = AliveVertex;
fn index(&self, idx: VertexId) -> &Self::Output {
self.lines.index(idx.0)
}
}
impl std::ops::IndexMut<VertexId> for Graph {
fn index_mut(&mut self, idx: VertexId) -> &mut Self::Output {
self.lines.index_mut(idx.0)
}
}
impl Graph {
pub(crate) fn children(&self, i: VertexId) -> &[(Option<Edge>, VertexId)] {
let ref line = self[i];
&self.children[line.children..line.children + line.n_children]
}
fn child(&self, i: VertexId, j: usize) -> &(Option<Edge>, VertexId) {
&self.children[self[i].children + j]
}
}
use std::collections::{HashMap, HashSet};
pub(crate) fn remove_redundant_children(
graph: &Graph,
vids: &HashMap<Vertex<ChangeId>, crate::alive::VertexId>,
vertices: &mut HashSet<Vertex<ChangeId>>,
target: Vertex<ChangeId>,
) {
let mut min = std::usize::MAX;
let mut stack = Vec::new();
for p in vertices.iter() {
let vid = if let Some(vid) = vids.get(p) {
*vid
} else {
continue;
};
min = min.min(graph[vid].scc);
stack.push(vid);
}
let target_scc = if let Some(&target) = vids.get(&target) {
graph[target].scc
} else {
std::usize::MAX
};
let mut visited = HashSet::new();
while let Some(p) = stack.pop() {
if !visited.insert(p) {
continue;
}
for (_, child) in graph.children(p) {
if graph[p].scc < target_scc && graph[p].scc != graph[*child].scc {
assert!(graph[p].scc > graph[*child].scc);
vertices.remove(&graph[*child].vertex);
}
if graph[*child].scc >= min {
stack.push(*child);
}
}
}
}
pub(crate) fn remove_redundant_parents(
graph: &Graph,
vids: &HashMap<Vertex<ChangeId>, crate::alive::VertexId>,
vertices: &mut HashSet<Vertex<ChangeId>>,
covered: &mut HashSet<(Vertex<ChangeId>, Vertex<ChangeId>)>,
target: Vertex<ChangeId>,
) {
let mut min = std::usize::MAX;
let mut stack = Vec::new();
for p in vertices.iter() {
let vid = if let Some(vid) = vids.get(p) {
*vid
} else {
continue;
};
min = min.min(graph[vid].scc);
stack.push((vid, false));
}
stack.sort_by(|(a, _), (b, _)| graph[*a].scc.cmp(&graph[*b].scc));
let target_scc = if let Some(&target) = vids.get(&target) {
graph[target].scc
} else {
0
};
let mut visited = HashSet::new();
while let Some((p, _)) = stack.pop() {
if !visited.insert(p) {
continue;
}
if graph[p].scc > target_scc
&& (vertices.contains(&graph[p].vertex) || covered.contains(&(graph[p].vertex, target)))
{
for (pp, pp_on_path) in stack.iter() {
if graph[*pp].scc != graph[p].scc && *pp_on_path {
vertices.remove(&graph[*pp].vertex);
covered.insert((graph[*pp].vertex, target));
}
}
}
stack.push((p, true));
for (_, child) in graph.children(p) {
if graph[*child].scc >= min {
stack.push((*child, false));
}
if graph[p].scc > target_scc
&& graph[*child].scc != graph[p].scc
&& covered.contains(&(graph[*child].vertex, target))
{
assert!(graph[*child].scc < graph[p].scc);
vertices.remove(&graph[p].vertex);
covered.insert((graph[p].vertex, target));
}
}
}
}