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Fix accidently quadratic syntax rewriter

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Switching from SyntaxNode to GreenNode is a costly operation (b/c
dereferencing a synax ptr in `with_green` is linear), so we should
avoid that.
This commit is contained in:
Aleksey Kladov 2020-12-10 20:07:37 +03:00
parent 78de7f0d4a
commit 3d5be5ba5b
1 changed files with 14 additions and 8 deletions
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22
crates/syntax/src/algo.rs
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@ -476,7 +476,8 @@ pub fn rewrite(&self, node: &SyntaxNode) -> SyntaxNode {
if self.f.is_none() && self.replacements.is_empty() && self.insertions.is_empty() {
return node.clone();
}
self.rewrite_children(node)
let green = self.rewrite_children(node);
with_green(node, green)
}
pub fn rewrite_ast<N: AstNode>(self, node: &N) -> N {
@ -523,7 +524,7 @@ fn insertions(&self, pos: &InsertPos) -> Option<impl Iterator<Item = SyntaxEleme
self.insertions.get(pos).map(|insertions| insertions.iter().cloned())
}
fn rewrite_children(&self, node: &SyntaxNode) -> SyntaxNode {
fn rewrite_children(&self, node: &SyntaxNode) -> rowan::GreenNode {
let _p = profile::span("rewrite_children");
// FIXME: this could be made much faster.
@ -534,7 +535,8 @@ fn rewrite_children(&self, node: &SyntaxNode) -> SyntaxNode {
for child in node.children_with_tokens() {
self.rewrite_self(&mut new_children, &child);
}
with_children(node, new_children)
rowan::GreenNode::new(rowan::SyntaxKind(node.kind() as u16), new_children)
}
fn rewrite_self(
@ -556,7 +558,7 @@ fn rewrite_self(
match element {
NodeOrToken::Token(it) => acc.push(NodeOrToken::Token(it.green().clone())),
NodeOrToken::Node(it) => {
acc.push(NodeOrToken::Node(self.rewrite_children(it).green().clone()));
acc.push(NodeOrToken::Node(self.rewrite_children(it)));
}
}
}
@ -601,14 +603,18 @@ fn with_children(
) -> SyntaxNode {
let _p = profile::span("with_children");
let len = new_children.iter().map(|it| it.text_len()).sum::<TextSize>();
let new_node = rowan::GreenNode::new(rowan::SyntaxKind(parent.kind() as u16), new_children);
let new_root_node = parent.replace_with(new_node);
let new_green = rowan::GreenNode::new(rowan::SyntaxKind(parent.kind() as u16), new_children);
with_green(parent, new_green)
}
fn with_green(syntax_node: &SyntaxNode, green: rowan::GreenNode) -> SyntaxNode {
let len = green.children().map(|it| it.text_len()).sum::<TextSize>();
let new_root_node = syntax_node.replace_with(green);
let new_root_node = SyntaxNode::new_root(new_root_node);
// FIXME: use a more elegant way to re-fetch the node (#1185), make
// `range` private afterwards
let mut ptr = SyntaxNodePtr::new(parent);
let mut ptr = SyntaxNodePtr::new(syntax_node);
ptr.range = TextRange::at(ptr.range.start(), len);
ptr.to_node(&new_root_node)
}