editor: Use less memory when replacing literal strings (#46092)

Marco Mihai Condrache created 6 days ago

Found while profiling #38927

When the query is not a regex, the same replacement can be applied to
all matches. Previously, `replacement_for` allocated a new String on
every call, while `replacement` returns a reference.

Release Notes:

- N/A

---------

Signed-off-by: Marco Mihai Condrache <[e-mail]>

Change summary

crates/editor/src/items.rs | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)

Detailed changes

crates/editor/src/items.rs

@@ -1682,19 +1682,27 @@ impl SearchableItem for Editor {
         let text = text.snapshot(cx);
         let mut edits = vec![];
 
-        for m in matches {
-            let text = text.text_for_range(m.clone()).collect::<Vec<_>>();
-
-            let text: Cow<_> = if text.len() == 1 {
-                text.first().cloned().unwrap().into()
-            } else {
-                let joined_chunks = text.join("");
-                joined_chunks.into()
-            };
+        // A regex might have replacement variables so we cannot apply
+        // the same replacement to all matches
+        if query.is_regex() {
+            edits = matches
+                .filter_map(|m| {
+                    let text = text.text_for_range(m.clone()).collect::<Vec<_>>();
+
+                    let text: Cow<_> = if text.len() == 1 {
+                        text.first().cloned().unwrap().into()
+                    } else {
+                        let joined_chunks = text.join("");
+                        joined_chunks.into()
+                    };
 
-            if let Some(replacement) = query.replacement_for(&text) {
-                edits.push((m.clone(), Arc::from(&*replacement)));
-            }
+                    query
+                        .replacement_for(&text)
+                        .map(|replacement| (m.clone(), Arc::from(&*replacement)))
+                })
+                .collect();
+        } else if let Some(replacement) = query.replacement().map(Arc::<str>::from) {
+            edits = matches.map(|m| (m.clone(), replacement.clone())).collect();
         }
 
         if !edits.is_empty() {