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Fix O(n²) complexity in collect_inline_roots_in_range #403

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Fix O(n²) complexity in collect_inline_roots_in_range #403

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9b952e7
Fix O(n²) complexity in collect_inline_roots_in_range using HashSet
lainon1 Apr 27, 2026
2e2e10c
Fix O(n²) complexity in collect_inline_roots_in_range
lainon1 Apr 27, 2026
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104 changes: 43 additions & 61 deletions packages/blitz-dom/src/traversal.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -367,77 +367,59 @@ impl BaseDocument {
};

let mut result = Vec::new();
let mut found_first = false;

// Traverse tree in document order
for node_id in TreeTraverser::new(self) {
if !found_first {
if node_id == first_anchor {
found_first = true;
if let Some(anon_id) = first_anon {
// First is anonymous: collect from this parent starting at anon_id
// Stop at last_anchor if different parent, or last_anon if same parent
let stop_at = if first_anchor == last_anchor {
// Same parent: stop at last_anon
last_anon
} else {
// Different parents: stop at last_anchor (which is a child of first_anchor)
Some(last_anchor)
};
self.collect_layout_children_inline_roots(
node_id,
Some(anon_id),
stop_at,
&mut result,
);
// If we collected up to last, we're done
if result.last() == Some(&last_anchor)
|| last_anon.is_some_and(|la| result.last() == Some(&la))
{
break;
}
continue;
}
}
}

if found_first {
if node_id == last_anchor {
if let Some(anon_id) = last_anon {
// Last is anonymous: collect up to anon_id (exclusive), then include anon_id
self.collect_layout_children_inline_roots(
node_id,
None,
Some(anon_id),
&mut result,
);
// Include the last_anon itself (until is exclusive, so we add it here)
if !result.contains(&anon_id) {
result.push(anon_id);
}
// Start traversal from first_anchor instead of root.
// This ensures we only visit nodes in range [first_anchor, last_anchor] by construction,
// so no duplicate tracking is needed.
for node_id in TreeTraverser::new_with_root(self, first_anchor) {
// Handle first node (anonymous case)
if node_id == first_anchor {
if let Some(anon_id) = first_anon {
let stop_at = if first_anchor == last_anchor {
last_anon
} else {
// Last is regular: include it if it's an inline root and not already collected
let node = &self.nodes[node_id];
if node.flags.is_inline_root() && !result.contains(&node_id) {
result.push(node_id);
}
}
break;
Some(last_anchor)
};
self.collect_layout_children_inline_roots(
node_id,
Some(anon_id),
stop_at,
&mut result,
);
continue;
}
}

let node = &self.nodes[node_id];
if node.flags.is_inline_root() && !result.contains(&node_id) {
result.push(node_id);
} else {
// For non-inline-root nodes, collect any inline roots from their layout_children
// This handles intermediate block containers with anonymous block children
// Check if we've reached the end
if node_id == last_anchor {
if let Some(anon_id) = last_anon {
self.collect_layout_children_inline_roots(
node_id,
None,
Some(last_anchor),
Some(anon_id),
&mut result,
);
result.push(anon_id);
} else {
let node = &self.nodes[node_id];
if node.flags.is_inline_root() {
result.push(node_id);
}
}
break;
}

// Process nodes between first and last (not first_anon handled above)
let node = &self.nodes[node_id];
if node.flags.is_inline_root() {
result.push(node_id);
} else {
self.collect_layout_children_inline_roots(
node_id,
None,
Some(last_anchor),
&mut result,
);
}
}

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