Optimize syntax update to only do partial updates

Signed-off-by: Hanif Bin Ariffin <[email protected]>

lapce-core/src/syntax/edit.rs

@@ -3,7 +3,7 @@ use tree_sitter::Point;
 
 use crate::buffer::rope_text::{RopeText, RopeTextRef};
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct SyntaxEdit(pub(crate) Vec<tree_sitter::InputEdit>);
 
 impl SyntaxEdit {

lapce-core/src/syntax/mod.rs

@@ -590,14 +590,33 @@ impl Syntax {
  let _ = layers.update(self.rev, new_rev, &new_text, edits);
  let tree = layers.try_tree();
 
- let styles = if tree.is_some() {
+ let (start_offset, end_offset) = match edits {
+ Some(edits) => (
+ edits
+ .iter()
+ .flat_map(|e| e.0.iter())
+ .flat_map(|e| [e.start_byte, e.old_end_byte, e.new_end_byte])
+ .min()
+ .unwrap_or(0),
+ edits
+ .iter()
+ .flat_map(|e| e.0.iter())
+ .flat_map(|e| [e.start_byte, e.old_end_byte, e.new_end_byte])
+ .max()
+ .unwrap_or(new_text.len()),
+ ),
+ None => (0usize, new_text.len()),
+ };
+
+ let new_styles = if tree.is_some() {
  let mut current_hl: Option<Highlight> = None;
  let mut highlights: SpansBuilder<Style> =
  SpansBuilder::new(new_text.len());
 
  // TODO: Should we be ignoring highlight errors via flattening them?
- for highlight in layers
- .highlight_iter(&new_text, Some(0..new_text.len()), None)
+ for highlight in self
+ .layers
+ .highlight_iter(&new_text, Some(start_offset..end_offset), None)
  .flatten()
  {
  match highlight {
@@ -644,7 +663,19 @@ impl Syntax {
  self.rev = new_rev;
  self.lens = lens;
  self.normal_lines = normal_lines;
- self.styles = styles;
+ self.styles = match (self.styles.as_mut(), new_styles) {
+ (Some(styles), Some(new_styles)) => {
+ Some(Arc::new(styles.merge(&new_styles, |a, b| {
+ if let Some(b) = b {
+ return b.clone();
+ }
+ a.clone()
+ })))
+ }
+ (None, Some(new_styles)) => Some(new_styles),
+ (Some(styles), None) => Some(styles.clone()),
+ _ => None,
+ };
  self.text = new_text
  }