perf: move swc transform into another thread

crates/rspack_loader_swc/src/lib.rs

@@ -10,6 +10,7 @@ use compiler::{IntoJsAst, SwcCompiler};
 use options::SwcCompilerOptionsWithAdditional;
 pub use options::SwcLoaderJsOptions;
 use rspack_core::{rspack_sources::SourceMap, Mode, RunnerContext};
+use rspack_error::miette::{Error, IntoDiagnostic};
 use rspack_error::{error, AnyhowError, Diagnostic, Result};
 use rspack_loader_runner::{Identifiable, Identifier, Loader, LoaderContext};
 use rspack_plugin_javascript::ast::{self, SourceMapConfig};
@@ -43,7 +44,7 @@ impl SwcLoader {
  self
  }
 
- fn loader_impl(&self, loader_context: &mut LoaderContext<RunnerContext>) -> Result<()> {
+ async fn loader_impl(&self, loader_context: &mut LoaderContext<RunnerContext>) -> Result<()> {
  let resource_path = loader_context
  .resource_path()
  .map(|p| p.to_path_buf())
@@ -87,56 +88,67 @@ impl SwcLoader {
  };
 
  let source = content.into_string_lossy();
- let c = SwcCompiler::new(
- resource_path.into_std_path_buf(),
- source.clone(),
- swc_options,
- )
- .map_err(AnyhowError::from)?;
-
- let built = c
- .parse(None, |_| {
- transformer::transform(&self.options_with_additional.rspack_experiments)
- })
+ let options_with_additional = self.options_with_additional.clone();
+ let (code, map) = tokio::task::spawn_blocking(move || {
+ let c = SwcCompiler::new(
+ resource_path.into_std_path_buf(),
+ source.clone(),
+ swc_options,
+ )
  .map_err(AnyhowError::from)?;
 
- let input_source_map = c
- .input_source_map(&built.input_source_map)
- .map_err(|e| error!(e.to_string()))?;
- let mut codegen_options = ast::CodegenOptions {
- target: Some(built.target),
- minify: Some(built.minify),
- input_source_map: input_source_map.as_ref(),
- ascii_only: built
- .output
-  .charset
- .as_ref()
- .map(|v| matches!(v, OutputCharset::Ascii)),
- source_map_config: SourceMapConfig {
- enable: source_map_kind.source_map(),
- inline_sources_content: source_map_kind.source_map(),
- emit_columns: !source_map_kind.cheap(),
- names: Default::default(),
- },
- inline_script: Some(false),
- keep_comments: Some(true),
- };
-
- let program = tokio::task::block_in_place(|| c.transform(built).map_err(AnyhowError::from))?;
- if source_map_kind.enabled() {
- let mut v = IdentCollector {
- names: Default::default(),
+  let built = c
+  .parse(None, |_| {
+  transformer::transform(&options_with_additional.rspack_experiments)
+  })
+  .map_err(AnyhowError::from)?;
+
+ let input_source_map = c
+  .input_source_map(&built.input_source_map)
+ .map_err(|e| error!(e.to_string()))?;
+ let mut codegen_options = ast::CodegenOptions {
+ target: Some(built.target),
+ minify: Some(built.minify),
+  input_source_map: input_source_map.as_ref(),
+ ascii_only: built
+  .output
+  .charset
+  .as_ref()
+  .map(|v| matches!(v, OutputCharset::Ascii)),
+  source_map_config: SourceMapConfig {
+  enable: source_map_kind.source_map(),
+  inline_sources_content: source_map_kind.source_map(),
+ emit_columns: !source_map_kind.cheap(),
+  names: Default::default(),
+  },
+  inline_script: Some(false),
+ keep_comments: Some(true),
  };
- program.visit_with(&mut v);
- codegen_options.source_map_config.names = v.names;
- }
- let ast = c.into_js_ast(program);
- let TransformOutput { code, map } = ast::stringify(&ast, codegen_options)?;
+ let program = c.transform(built).map_err(AnyhowError::from)?;
+ if source_map_kind.enabled() {
+ let mut v = IdentCollector {
+ names: Default::default(),
+ };
+ program.visit_with(&mut v);
+ codegen_options.source_map_config.names = v.names;
+ }
+ let ast = c.into_js_ast(program);
+ let TransformOutput { code, map } = ast::stringify(&ast, codegen_options)?;
+ let map = map
+ .map(|m| SourceMap::from_json(&m))
+ .transpose()
+ .map_err(|e| error!(e.to_string()))?;
+ Ok::<
+ (
+ std::string::String,
+ std::option::Option<rspack_core::rspack_sources::SourceMap>,
+ ),
+ Error,
+ >((code, map))
+ })
+ .await
+ .into_diagnostic()??;
 
- let map = map
- .map(|m| SourceMap::from_json(&m))
- .transpose()
- .map_err(|e| error!(e.to_string()))?;
  loader_context.finish_with((code, map));
 
  Ok(())
@@ -148,19 +160,7 @@ pub const SWC_LOADER_IDENTIFIER: &str = "builtin:swc-loader";
 #[async_trait::async_trait]
 impl Loader<RunnerContext> for SwcLoader {
  async fn run(&self, loader_context: &mut LoaderContext<RunnerContext>) -> Result<()> {
- #[allow(unused_mut)]
- let mut inner = || self.loader_impl(loader_context);
- #[cfg(debug_assertions)]
- {
- // Adjust stack to avoid stack overflow.
- stacker::maybe_grow(
- 2 * 1024 * 1024, /* 2mb */
- 4 * 1024 * 1024, /* 4mb */
- inner,
- )
- }
- #[cfg(not(debug_assertions))]
- inner()
+ self.loader_impl(loader_context).await
  }
 }
 

crates/rspack_loader_swc/src/options.rs

@@ -12,7 +12,7 @@ pub struct RawRspackExperiments {
  pub import: Option<Vec<RawImportOptions>>,
 }
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone)]
 pub(crate) struct RspackExperiments {
  pub(crate) import: Option<Vec<ImportOptions>>,
 }
@@ -74,7 +74,7 @@ pub struct SwcLoaderJsOptions {
  pub rspack_experiments: Option<RawRspackExperiments>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub(crate) struct SwcCompilerOptionsWithAdditional {
  pub(crate) swc_options: Options,
  pub(crate) rspack_experiments: RspackExperiments,