perf(es/parser): Remove Rc<RefCell<T>> in Capturing (#11058)

**Description:**

Similar to #11002

**BREAKING CHANGE:**

This is a breaking change, but the `Capturing` feature is marked as unstable.

Author: CPunisher

.changeset/mighty-buckets-walk.md

@@ -0,0 +1,5 @@
+---
+swc_ecma_parser: major
+---
+
+perf: remove `Rc<RefCell<T>>` in `Capturing`

Cargo.lock

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, mem, rc::Rc};
+use std::mem;
 
 use swc_ecma_lexer::common::syntax::SyntaxFlags;
 
@@ -7,7 +7,12 @@ use crate::{input::Tokens, lexer::token::TokenAndSpan};
 #[derive(Debug)]
 pub struct Capturing<I> {
     inner: I,
-    captured: Rc<RefCell<Vec<TokenAndSpan>>>,
+    captured: Vec<TokenAndSpan>,
+}
+
+pub struct CapturingCheckpoint<I: swc_ecma_lexer::common::input::Tokens<TokenAndSpan>> {
+    pos: usize,
+    inner: I::Checkpoint,
 }
 
 impl<I: Clone> Clone for Capturing<I> {
@@ -27,13 +32,13 @@ impl<I> Capturing<I> {
         }
     }
 
-    pub fn tokens(&self) -> Rc<RefCell<Vec<TokenAndSpan>>> {
-        self.captured.clone()
+    pub fn tokens(&self) -> &[TokenAndSpan] {
+        &self.captured
     }
 
     /// Take captured tokens
     pub fn take(&mut self) -> Vec<TokenAndSpan> {
-        mem::take(&mut *self.captured.borrow_mut())
+        mem::take(&mut self.captured)
     }
 }
 
@@ -45,19 +50,8 @@ impl<I: Iterator<Item = TokenAndSpan>> Iterator for Capturing<I> {
 
         match next {
             Some(ts) => {
-                let mut v = self.captured.borrow_mut();
-
-                // remove tokens that could change due to backtracing
-                while let Some(last) = v.last() {
-                    if last.span.lo >= ts.span.lo {
-                        v.pop();
-                    } else {
-                        break;
-                    }
-                }
-
+                let v = &mut self.captured;
                 v.push(ts);
-
                 Some(ts)
             }
             None => None,
@@ -68,14 +62,18 @@ impl<I: Iterator<Item = TokenAndSpan>> Iterator for Capturing<I> {
 impl<I: swc_ecma_lexer::common::input::Tokens<TokenAndSpan>>
     swc_ecma_lexer::common::input::Tokens<TokenAndSpan> for Capturing<I>
 {
-    type Checkpoint = I::Checkpoint;
+    type Checkpoint = CapturingCheckpoint<I>;
 
     fn checkpoint_save(&self) -> Self::Checkpoint {
-        self.inner.checkpoint_save()
+        Self::Checkpoint {
+            pos: self.captured.len(),
+            inner: self.inner.checkpoint_save(),
+        }
     }
 
     fn checkpoint_load(&mut self, checkpoint: Self::Checkpoint) {
-        self.inner.checkpoint_load(checkpoint);
+        self.captured.truncate(checkpoint.pos);
+        self.inner.checkpoint_load(checkpoint.inner);
     }
 
     fn set_ctx(&mut self, ctx: swc_ecma_lexer::common::context::Context) {

crates/swc_ecma_parser/src/lexer/capturing.rs

@@ -15,16 +15,16 @@ default = []
 nightly = []
 
 [dependencies]
-anyhow       = { workspace = true }
-bytes-str    = { workspace = true }
-serde        = { workspace = true, features = ["derive"] }
-wasm-bindgen = { workspace = true, optional = true }
+anyhow = { workspace = true }
+bytes-str = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
 swc_atoms = { version = "7.0.0", path = "../swc_atoms" }
 swc_common = { version = "14.0.3", path = "../swc_common", features = [
   "sourcemap",
 ] }
 swc_ecma_ast = { version = "15.0.0", path = "../swc_ecma_ast" }
 swc_ecma_codegen = { version = "17.0.0", path = "../swc_ecma_codegen" }
+swc_ecma_lexer = { version = "23.0.0", path = "../swc_ecma_lexer" }
 swc_ecma_parser = { version = "23.0.0", path = "../swc_ecma_parser", default-features = false, features = [
   "typescript",
   "unstable",
@@ -33,6 +33,7 @@ swc_ecma_transforms_base = { version = "25.0.0", path = "../swc_ecma_transforms_
 swc_ecma_transforms_react = { version = "28.0.0", path = "../swc_ecma_transforms_react" }
 swc_ecma_transforms_typescript = { version = "28.0.0", path = "../swc_ecma_transforms_typescript" }
 swc_ecma_visit = { version = "15.0.0", path = "../swc_ecma_visit" }
+wasm-bindgen = { workspace = true, optional = true }
 
 [dev-dependencies]
 codspeed-criterion-compat = { workspace = true }

crates/swc_ts_fast_strip/Cargo.toml

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, fmt::Display, rc::Rc};
+use std::fmt::Display;
 
 use anyhow::Context;
 use bytes_str::BytesStr;
@@ -21,6 +21,7 @@ use swc_ecma_ast::{
     TsSatisfiesExpr, TsTypeAliasDecl, TsTypeAnn, TsTypeAssertion, TsTypeParamDecl,
     TsTypeParamInstantiation, VarDeclarator, WhileStmt, YieldExpr,
 };
+use swc_ecma_lexer::common::parser::{buffer::Buffer, Parser as _};
 use swc_ecma_parser::{
     lexer::Lexer,
     unstable::{Capturing, Token, TokenAndSpan, TokenFactory},
@@ -251,8 +252,6 @@ pub fn operate(
         StringInput::from(&*fm),
         Some(&comments),
     ));
-    let tokens = lexer.tokens().clone();
-
     let mut parser = Parser::new_from(lexer);
 
     let program = match options.module {
@@ -261,6 +260,7 @@ pub fn operate(
         None => parser.parse_program(),
     };
     let errors = parser.take_errors();
+    let mut tokens = parser.input_mut().iter_mut().take();
 
     let mut program = match program {
         Ok(program) => program,
@@ -301,8 +301,6 @@ pub fn operate(
 
     match options.mode {
         Mode::StripOnly => {
-            let mut tokens = RefCell::into_inner(Rc::try_unwrap(tokens).unwrap());
-
             tokens.sort_by_key(|t| t.span);
 
             if deprecated_ts_module_as_error {
@@ -418,8 +416,6 @@ pub fn operate(
                 program.mutate(&mut resolver(unresolved_mark, top_level_mark, true));
 
                 if deprecated_ts_module_as_error {
-                    let mut tokens = RefCell::into_inner(Rc::try_unwrap(tokens).unwrap());
-
                     tokens.sort_by_key(|t| t.span);
 
                     program.visit_with(&mut ErrorOnTsModule {