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prepass: use hash set to avoid duplicate heading ids

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linear lookup becomes problematic for large amount of headings with same
title
This commit is contained in:
Noah Hellman 2023-01-31 22:49:10 +01:00
parent 6a94e694f9
commit 87d4f7c270
1 changed files with 9 additions and 2 deletions
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11
src/lib.rs
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@ -378,6 +378,7 @@ impl<'s> PrePass<'s> {
fn new(src: &'s str, mut tree: block::Tree) -> Self { fn new(src: &'s str, mut tree: block::Tree) -> Self {
let mut link_definitions = std::collections::HashMap::new(); let mut link_definitions = std::collections::HashMap::new();
let mut headings: Vec<Heading> = Vec::new(); let mut headings: Vec<Heading> = Vec::new();
let mut used_ids: std::collections::HashSet<&str> = std::collections::HashSet::new();
let mut inlines = span::InlineSpans::new(src); let mut inlines = span::InlineSpans::new(src);
@ -435,7 +436,7 @@ impl<'s> PrePass<'s> {
id_auto.drain(id_auto.trim_end_matches('-').len()..); id_auto.drain(id_auto.trim_end_matches('-').len()..);
// ensure id unique // ensure id unique
if headings.iter().any(|h| h.id_auto == id_auto) || id_auto.is_empty() { if used_ids.contains::<str>(&id_auto) || id_auto.is_empty() {
if id_auto.is_empty() { if id_auto.is_empty() {
id_auto.push('s'); id_auto.push('s');
} }
@ -443,13 +444,19 @@ impl<'s> PrePass<'s> {
id_auto.push('-'); id_auto.push('-');
let i_num = id_auto.len(); let i_num = id_auto.len();
write!(id_auto, "{}", num).unwrap(); write!(id_auto, "{}", num).unwrap();
while headings.iter().any(|h| h.id_auto == id_auto) { while used_ids.contains::<str>(&id_auto) {
num += 1; num += 1;
id_auto.drain(i_num..); id_auto.drain(i_num..);
write!(id_auto, "{}", num).unwrap(); write!(id_auto, "{}", num).unwrap();
} }
} }
// SAFETY: used_ids is dropped before the id_auto strings in headings. even if
// the strings move due to headings reallocating, the string data on the heap
// will not move
used_ids.insert(unsafe {
std::mem::transmute::<&str, &'static str>(id_auto.as_ref())
});
headings.push(Heading { headings.push(Heading {
location: e.span.start(), location: e.span.start(),
id_auto, id_auto,