perf(sourcemap): search lines count at parallel (#806)

Cargo.toml

@@ -78,6 +78,7 @@ dunce                     = "1.0.4"
 futures                   = "0.3.30"
 index_vec                 = "0.1.3"
 insta                     = "1.38.0"
+memchr                    = "2.7.2"
 mimalloc                  = "0.1.39"
 napi                      = { version = "3.0.0-alpha.0", features = ["async"] }
 napi-build                = { version = "2.1.2" }

crates/rolldown/src/chunk/mod.rs

@@ -117,10 +117,15 @@ impl Chunk {
           rendered_module,
           rendered_content,
           sourcemap,
+          lines_count,
         } = module_render_output;
         concat_source.add_source(Box::new(RawSource::new(format!("// {module_pretty_path}",))));
         if let Some(sourcemap) = sourcemap {
-          concat_source.add_source(Box::new(SourceMapSource::new(rendered_content, sourcemap)));
+          concat_source.add_source(Box::new(SourceMapSource::new(
+            rendered_content,
+            sourcemap,
+            lines_count,
+          )));
         } else {
           concat_source.add_source(Box::new(RawSource::new(rendered_content)));
         }

crates/rolldown/src/types/module_render_output.rs

@@ -7,4 +7,5 @@ pub struct ModuleRenderOutput<'a> {
   pub rendered_module: RenderedModule,
   pub rendered_content: String,
   pub sourcemap: Option<SourceMap>,
+  pub lines_count: u32,
 }

crates/rolldown/src/utils/render_normal_module.rs

@@ -1,6 +1,6 @@
 use rolldown_common::{NormalModule, RenderedModule};
 use rolldown_oxc_utils::{OxcCompiler, OxcProgram};
-use rolldown_sourcemap::collapse_sourcemaps;
+use rolldown_sourcemap::{collapse_sourcemaps, lines_count};
 
 use crate::{types::module_render_output::ModuleRenderOutput, SharedOptions};
 
@@ -25,6 +25,8 @@ pub fn render_normal_module<'a>(
       module_path: module.resource_id.expect_file().as_str(),
       module_pretty_path: &module.pretty_path,
       rendered_module: RenderedModule { code: None },
+      // Search lines count from rendered content has a little overhead, so make it at parallel.
+      lines_count: lines_count(&render_output.source_text),
       rendered_content: render_output.source_text,
       sourcemap: if options.sourcemap.is_hidden() {
         None

crates/rolldown_sourcemap/Cargo.toml

@@ -18,6 +18,6 @@ doctest = false
 test    = false
 
 [dependencies]
+memchr     = { workspace = true }
 oxc        = { workspace = true }
-rustc-hash = { workspace = true }
 sugar_path = { workspace = true }

crates/rolldown_sourcemap/src/concat_sourcemap.rs

@@ -1,9 +1,12 @@
 // cSpell:disable
 use oxc::sourcemap::{ConcatSourceMapBuilder, SourceMap};
 
+use crate::lines_count;
+
 pub trait Source {
   fn sourcemap(&self) -> Option<&SourceMap>;
   fn content(&self) -> &String;
+  fn lines_count(&self) -> u32;
   #[allow(clippy::wrong_self_convention)]
   fn into_concat_source(
     &self,
@@ -32,6 +35,10 @@ impl Source for RawSource {
     &self.content
   }
 
+  fn lines_count(&self) -> u32 {
+    lines_count(&self.content)
+  }
+
   fn into_concat_source(
     &self,
     final_source: &mut String,
@@ -45,11 +52,12 @@ impl Source for RawSource {
 pub struct SourceMapSource {
   content: String,
   sourcemap: SourceMap,
+  lines_count: u32,
 }
 
 impl SourceMapSource {
-  pub fn new(content: String, sourcemap: SourceMap) -> Self {
-    Self { content, sourcemap }
+  pub fn new(content: String, sourcemap: SourceMap, lines_count: u32) -> Self {
+    Self { content, sourcemap, lines_count }
   }
 }
 
@@ -62,6 +70,10 @@ impl Source for SourceMapSource {
     &self.content
   }
 
+  fn lines_count(&self) -> u32 {
+    self.lines_count
+  }
+
   #[allow(clippy::cast_possible_truncation)]
   fn into_concat_source(
     &self,
@@ -110,7 +122,7 @@ impl ConcatSource {
       source.into_concat_source(&mut final_source, &mut sourcemap_builder, line_offset);
       if index < source_len - 1 {
         final_source.push('\n');
-        line_offset += source.content().matches('\n').count() as u32 + 1; // +1 for the newline
+        line_offset += source.lines_count() + 1; // +1 for the newline
       }
     }
 
@@ -141,7 +153,7 @@ mod tests {
           "names":[]
         }"#
     )
-    .unwrap().into(),
+    .unwrap().into(),3
     )));
 
     let (content, map) = {

crates/rolldown_sourcemap/src/lib.rs

@@ -3,7 +3,8 @@ use sugar_path::SugarPath;
 // cSpell:disable
 pub use concat_sourcemap::{ConcatSource, RawSource, SourceMapSource};
 pub use oxc::sourcemap::{SourceMap, SourcemapVisualizer};
-
+mod lines_count;
+pub use lines_count::lines_count;
 use oxc::sourcemap::SourceMapBuilder;
 mod concat_sourcemap;
 

crates/rolldown_sourcemap/src/lines_count.rs

@@ -0,0 +1,14 @@
+use memchr::memmem;
+
+#[allow(clippy::cast_possible_truncation)]
+#[inline]
+pub fn lines_count(str: &str) -> u32 {
+  memmem::find_iter(str.as_bytes(), "\n").count() as u32
+}
+
+#[test]
+fn test() {
+  assert_eq!(lines_count("a\nb\nc"), 2);
+  assert_eq!(lines_count("a\nb\nc\n"), 3);
+  assert_eq!(lines_count("a"), 0);
+}

cspell.json

@@ -113,6 +113,8 @@
     "vitepress",
     "Yinan",
     "Yunfei",
-    "sourcemaps"
+    "sourcemaps",
+    "memmem",
+    "memchr"
   ]
 }