perf(transformer): memoize rope instance (#5518)

Currently only used in `jsx-source`, so memorize rope in JSXSource enough for now.

close: #5500

crates/oxc_transformer/src/react/jsx.rs

@@ -11,7 +11,7 @@ use oxc_syntax::{
 };
 use oxc_traverse::{Traverse, TraverseCtx};
 
-use super::{diagnostics, utils::get_line_column};
+use super::diagnostics;
 pub use super::{
     jsx_self::ReactJsxSelf,
     jsx_source::ReactJsxSource,
@@ -560,7 +560,7 @@ impl<'a> ReactJsx<'a> {
                 if let Some(span) = source_attr_span {
                     self.jsx_source.report_error(span);
                 } else {
-                    let (line, column) = get_line_column(e.span().start, self.ctx.source_text);
+                    let (line, column) = self.jsx_source.get_line_column(e.span().start);
                     properties.push(
                         self.jsx_source.get_object_property_kind_for_jsx_plugin(line, column, ctx),
                     );
@@ -614,7 +614,7 @@ impl<'a> ReactJsx<'a> {
                     if let Some(span) = source_attr_span {
                         self.jsx_source.report_error(span);
                     } else {
-                        let (line, column) = get_line_column(e.span().start, self.ctx.source_text);
+                        let (line, column) = self.jsx_source.get_line_column(e.span().start);
                         let expr = self.jsx_source.get_source_object(line, column, ctx);
                         arguments.push(Argument::from(expr));
                     }

crates/oxc_transformer/src/react/jsx_source.rs

@@ -3,6 +3,7 @@ use oxc_diagnostics::OxcDiagnostic;
 use oxc_span::{Span, SPAN};
 use oxc_syntax::{number::NumberBase, symbol::SymbolFlags};
 use oxc_traverse::{Traverse, TraverseCtx};
+use ropey::Rope;
 
 use super::utils::get_line_column;
 use crate::{context::Ctx, helpers::bindings::BoundIdentifier};
@@ -19,13 +20,14 @@ const FILE_NAME_VAR: &str = "jsxFileName";
 /// In: `<sometag />`
 /// Out: `<sometag __source={ { fileName: 'this/file.js', lineNumber: 10, columnNumber: 1 } } />`
 pub struct ReactJsxSource<'a> {
-    ctx: Ctx<'a>,
     filename_var: Option<BoundIdentifier<'a>>,
+    source_rope: Option<Rope>,
+    ctx: Ctx<'a>,
 }
 
 impl<'a> ReactJsxSource<'a> {
     pub fn new(ctx: Ctx<'a>) -> Self {
-        Self { ctx, filename_var: None }
+        Self { filename_var: None, source_rope: None, ctx }
     }
 }
 
@@ -40,6 +42,13 @@ impl<'a> Traverse<'a> for ReactJsxSource<'a> {
 }
 
 impl<'a> ReactJsxSource<'a> {
+    pub fn get_line_column(&mut self, offset: u32) -> (usize, usize) {
+        if self.source_rope.is_none() {
+            self.source_rope = Some(Rope::from_str(self.ctx.source_text));
+        }
+        get_line_column(self.source_rope.as_ref().unwrap(), offset, self.ctx.source_text)
+    }
+
     pub fn get_object_property_kind_for_jsx_plugin(
         &mut self,
         line: usize,
@@ -87,7 +96,7 @@ impl<'a> ReactJsxSource<'a> {
         // TODO: We shouldn't calculate line + column from scratch each time as it's expensive.
         // Build a table of byte indexes of each line's start on first usage, and save it.
         // Then calculate line and column from that.
-        let (line, column) = get_line_column(elem.span.start, self.ctx.source_text);
+        let (line, column) = self.get_line_column(elem.span.start);
         let object = self.get_source_object(line, column, ctx);
         let value = self
             .ctx

crates/oxc_transformer/src/react/utils.rs

@@ -6,9 +6,8 @@ use ropey::Rope;
 /// Column number is in UTF-16 characters, and starts at 1.
 ///
 /// This matches Babel's output.
-pub fn get_line_column(offset: u32, source_text: &str) -> (usize, usize) {
+pub fn get_line_column(rope: &Rope, offset: u32, source_text: &str) -> (usize, usize) {
     let offset = offset as usize;
-    let rope = Rope::from_str(source_text);
     // Get line number and byte offset of start of line
     let line_index = rope.byte_to_line(offset);
     let line_offset = rope.line_to_byte(line_index);
@@ -18,74 +17,84 @@ pub fn get_line_column(offset: u32, source_text: &str) -> (usize, usize) {
     (line_index + 1, column_index + 1)
 }
 
-#[test]
-fn empty_file() {
-    assert_eq!(get_line_column(0, ""), (1, 1));
-}
-
-#[test]
-fn first_line_start() {
-    assert_eq!(get_line_column(0, "foo\nbar\n"), (1, 1));
-}
-
-#[test]
-fn first_line_middle() {
-    assert_eq!(get_line_column(5, "blahblahblah\noops\n"), (1, 6));
-}
-
-#[test]
-fn later_line_start() {
-    assert_eq!(get_line_column(8, "foo\nbar\nblahblahblah"), (3, 1));
-}
-
-#[test]
-fn later_line_middle() {
-    assert_eq!(get_line_column(12, "foo\nbar\nblahblahblah"), (3, 5));
-}
-
-#[test]
-fn after_2_byte_unicode() {
-    assert_eq!("£".len(), 2);
-    assert_eq!(utf16_len("£"), 1);
-    assert_eq!(get_line_column(4, "£abc"), (1, 4));
-}
-
-#[test]
-fn after_3_byte_unicode() {
-    assert_eq!("अ".len(), 3);
-    assert_eq!(utf16_len("अ"), 1);
-    assert_eq!(get_line_column(5, "अabc"), (1, 4));
-}
-
-#[test]
-fn after_4_byte_unicode() {
-    assert_eq!("🍄".len(), 4);
-    assert_eq!(utf16_len("🍄"), 2);
-    assert_eq!(get_line_column(6, "🍄abc"), (1, 5));
-}
-
-#[test]
-fn after_2_byte_unicode_on_previous_line() {
-    assert_eq!("£".len(), 2);
-    assert_eq!(utf16_len("£"), 1);
-    assert_eq!(get_line_column(4, "£\nabc"), (2, 2));
-}
-
-#[test]
-fn after_3_byte_unicode_on_previous_line() {
-    assert_eq!("अ".len(), 3);
-    assert_eq!(utf16_len("अ"), 1);
-    assert_eq!(get_line_column(5, "अ\nabc"), (2, 2));
-}
-
-#[test]
-fn after_4_byte_unicode_on_previous_line() {
-    assert_eq!("🍄".len(), 4);
-    assert_eq!(utf16_len("🍄"), 2);
-    assert_eq!(get_line_column(6, "🍄\nabc"), (2, 2));
-}
-
 #[cfg(test)]
-fn utf16_len(s: &str) -> usize {
-    s.encode_utf16().count()
+mod test {
+    use ropey::Rope;
+
+    fn test_line_column(offset: u32, source_text: &str) -> (usize, usize) {
+        let rope = Rope::from_str(source_text);
+        super::get_line_column(&rope, offset, source_text)
+    }
+
+    #[test]
+    fn empty_file() {
+        assert_eq!(test_line_column(0, ""), (1, 1));
+    }
+
+    #[test]
+    fn first_line_start() {
+        assert_eq!(test_line_column(0, "foo\nbar\n"), (1, 1));
+    }
+
+    #[test]
+    fn first_line_middle() {
+        assert_eq!(test_line_column(5, "blahblahblah\noops\n"), (1, 6));
+    }
+
+    #[test]
+    fn later_line_start() {
+        assert_eq!(test_line_column(8, "foo\nbar\nblahblahblah"), (3, 1));
+    }
+
+    #[test]
+    fn later_line_middle() {
+        assert_eq!(test_line_column(12, "foo\nbar\nblahblahblah"), (3, 5));
+    }
+
+    #[test]
+    fn after_2_byte_unicode() {
+        assert_eq!("£".len(), 2);
+        assert_eq!(utf16_len("£"), 1);
+        assert_eq!(test_line_column(4, "£abc"), (1, 4));
+    }
+
+    #[test]
+    fn after_3_byte_unicode() {
+        assert_eq!("अ".len(), 3);
+        assert_eq!(utf16_len("अ"), 1);
+        assert_eq!(test_line_column(5, "अabc"), (1, 4));
+    }
+
+    #[test]
+    fn after_4_byte_unicode() {
+        assert_eq!("🍄".len(), 4);
+        assert_eq!(utf16_len("🍄"), 2);
+        assert_eq!(test_line_column(6, "🍄abc"), (1, 5));
+    }
+
+    #[test]
+    fn after_2_byte_unicode_on_previous_line() {
+        assert_eq!("£".len(), 2);
+        assert_eq!(utf16_len("£"), 1);
+        assert_eq!(test_line_column(4, "£\nabc"), (2, 2));
+    }
+
+    #[test]
+    fn after_3_byte_unicode_on_previous_line() {
+        assert_eq!("अ".len(), 3);
+        assert_eq!(utf16_len("अ"), 1);
+        assert_eq!(test_line_column(5, "अ\nabc"), (2, 2));
+    }
+
+    #[test]
+    fn after_4_byte_unicode_on_previous_line() {
+        assert_eq!("🍄".len(), 4);
+        assert_eq!(utf16_len("🍄"), 2);
+        assert_eq!(test_line_column(6, "🍄\nabc"), (2, 2));
+    }
+
+    #[cfg(test)]
+    fn utf16_len(s: &str) -> usize {
+        s.encode_utf16().count()
+    }
 }