perf: ReplaceSource

Author: SyMind

src/helpers.rs

@@ -13,6 +13,7 @@ use crate::{
  encoder::create_encoder,
  linear_map::LinearMap,
  source::{Mapping, OriginalLocation},
+ source_content_lines::SourceContentLines,
  with_indices::WithIndices,
  MapOptions, Rope, SourceMap,
 };
@@ -704,40 +705,6 @@ struct SourceMapLineData<'a> {
 type InnerSourceIndexValueMapping<'a> =
  LinearMap<(Cow<'a, str>, Option<&'a Arc<str>>)>;
 
-type Owner = Arc<str>;
-
-type BorrowedValue<'a> = Vec<WithIndices<'a, &'a str>>;
-
-self_cell::self_cell!(
- struct SourceContentLines {
- owner: Owner,
- #[covariant]
- dependent: BorrowedValue,
- }
-);
-
-impl SourceContentLines {
- pub fn get(&self, line: usize) -> Option<&WithIndices<'_, &str>> {
- self.borrow_dependent().get(line)
- }
-}
-
-impl From<Arc<str>> for SourceContentLines {
- fn from(value: Arc<str>) -> Self {
- SourceContentLines::new(value, |owner| {
- split_into_lines(&owner.as_ref())
- .map(WithIndices::new)
- .collect::<Vec<_>>()
- })
- }
-}
-
-impl From<&Arc<str>> for SourceContentLines {
- fn from(value: &Arc<str>) -> Self {
- Self::from(value.clone())
- }
-}
-
 #[allow(clippy::too_many_arguments)]
 pub fn stream_chunks_of_combined_source_map<'a, S>(
  source: S,
@@ -978,7 +945,7 @@ where
  let end = start + name.len();
  i.substring(start, end)
  });
- if Rope::from(&name) == original_name {
+ if name == original_name {
  let mut name_index_mapping = name_index_mapping.borrow_mut();
  final_name_index =
  name_index_mapping.get(&name_index).copied().unwrap_or(-2);

src/lib.rs

@@ -12,6 +12,7 @@ mod raw_source;
 mod replace_source;
 mod rope;
 mod source;
+mod source_content_lines;
 mod source_map_source;
 mod with_indices;
 

src/replace_source.rs

@@ -2,6 +2,7 @@ use std::{
  borrow::Cow,
  cell::RefCell,
  hash::{Hash, Hasher},
+ sync::Arc,
 };
 
 use rustc_hash::FxHashMap as HashMap;
@@ -12,7 +13,7 @@ use crate::{
  },
  linear_map::LinearMap,
  rope::Rope,
- with_indices::WithIndices,
+ source_content_lines::SourceContentLines,
  BoxSource, MapOptions, Mapping, OriginalLocation, Source, SourceExt,
  SourceMap, SourceValue,
 };
@@ -318,21 +319,22 @@ impl std::fmt::Debug for ReplaceSource {
  }
 }
 
-enum SourceContent<'a> {
- Raw(Rope<'a>),
- Lines(Vec<WithIndices<'a, Rope<'a>>>),
+enum SourceContent {
+ Raw(Arc<str>),
+ Lines(SourceContentLines),
 }
 
-fn check_content_at_position<'a>(
- lines: &[WithIndices<'a, Rope<'a>>],
+fn check_content_at_position(
+ lines: &SourceContentLines,
  line: u32,
  column: u32,
- expected: Rope, // FIXME: memory
+ expected: &Rope,
 ) -> bool {
  if let Some(line) = lines.get(line as usize - 1) {
  line
  .substring(column as usize, usize::MAX)
- .starts_with(&expected)
+ .into_rope()
+ .starts_with(expected)
  } else {
  false
  }
@@ -389,15 +391,13 @@ impl StreamChunks for ReplaceSource {
  // In this case, we can't split this mapping.
  // webpack-sources also have this function, refer https://github.com/webpack/webpack-sources/blob/main/lib/ReplaceSource.js#L158
  let check_original_content =
- |source_index: u32, line: u32, column: u32, expected_chunk: Rope| {
+ |source_index: u32, line: u32, column: u32, expected_chunk: &Rope| {
  if let Some(Some(source_content)) =
  source_content_lines.borrow_mut().get_mut(&source_index)
  {
  match source_content {
  SourceContent::Raw(source) => {
- let lines = split_into_lines(source)
- .map(WithIndices::new)
- .collect::<Vec<_>>();
+ let lines = SourceContentLines::from(&*source);
  let matched =
  check_content_at_position(&lines, line, column, expected_chunk);
  *source_content = SourceContent::Lines(lines);
@@ -451,7 +451,7 @@ impl StreamChunks for ReplaceSource {
  original.source_index,
  original.original_line,
  original.original_column,
- chunk.byte_slice(0..chunk_pos as usize),
+ &chunk.byte_slice(0..chunk_pos as usize),
  )
  }) {
  original.original_column += chunk_pos;
@@ -508,7 +508,7 @@ impl StreamChunks for ReplaceSource {
  original.source_index,
  original.original_line,
  original.original_column,
- chunk_slice.clone(),
+ &chunk_slice,
  )
  })
  {
@@ -628,7 +628,7 @@ impl StreamChunks for ReplaceSource {
  original.source_index,
  original.original_line,
  original.original_column,
- chunk.byte_slice(
+ &chunk.byte_slice(
  chunk_pos as usize..(chunk_pos + offset as u32) as usize,
  ),
  )
@@ -683,9 +683,8 @@ impl StreamChunks for ReplaceSource {
  },
  &mut |source_index, source, source_content| {
  let mut source_content_lines = source_content_lines.borrow_mut();
- let lines = source_content.map(|source_content| {
- SourceContent::Raw(source_content.as_ref().into())
- });
+ let lines = source_content
+ .map(|source_content| SourceContent::Raw(source_content.clone()));
  source_content_lines.insert(source_index, lines);
  on_source(source_index, source, source_content);
  },

src/source_content_lines.rs

@@ -0,0 +1,37 @@
+use std::sync::Arc;
+
+use crate::{helpers::split_into_lines, with_indices::WithIndices};
+
+type Owner = Arc<str>;
+
+type BorrowedValue<'a> = Vec<WithIndices<'a, &'a str>>;
+
+self_cell::self_cell!(
+ pub struct SourceContentLines {
+ owner: Owner,
+ #[covariant]
+ dependent: BorrowedValue,
+ }
+);
+
+impl SourceContentLines {
+ pub fn get(&self, line: usize) -> Option<&WithIndices<'_, &str>> {
+ self.borrow_dependent().get(line)
+ }
+}
+
+impl From<Arc<str>> for SourceContentLines {
+ fn from(value: Arc<str>) -> Self {
+ SourceContentLines::new(value, |owner| {
+ split_into_lines(&owner.as_ref())
+ .map(WithIndices::new)
+ .collect::<Vec<_>>()
+ })
+ }
+}
+
+impl From<&Arc<str>> for SourceContentLines {
+ fn from(value: &Arc<str>) -> Self {
+ Self::from(value.clone())
+ }
+}