perf(turbopack): Use rayon threadpool for minify() (#79261)

kdy1 · web-flow · commit e0c2e2aed75f · 2025-05-16T08:34:52.000-07:00
### What? Run `minify()` on the `rayon` threadpool instead of the `tokio` threadpool. ### Why? ES minification is a very CPU-intensive operation, and more importantly, it calls `rayon` internally anyway. So it's better to run it from the rayon thread pool from the start. It seems like this PR makes the total build ~ 3% faster, at the cost of a small RSS increase. x-ref: Numbers at https://vercel.slack.com/archives/C06PPGZ0FD3/p1747349799503749?thread_ts=1747349784.352809&cid=C06PPGZ0FD3
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/turbopack/crates/turbopack-browser/src/ecmascript/content.rs b/turbopack/crates/turbopack-browser/src/ecmascript/content.rs
@@ -128,7 +128,7 @@ impl EcmascriptBrowserChunkContent {
         let mut code = code.build();
 
         if let MinifyType::Minify { mangle } = this.chunking_context.await?.minify_type() {
-            code = minify(&code, source_maps, mangle)?;
+            code = minify(code, source_maps, mangle).await?;
         }
 
         Ok(code.cell())
diff --git a/turbopack/crates/turbopack-browser/src/ecmascript/evaluate/chunk.rs b/turbopack/crates/turbopack-browser/src/ecmascript/evaluate/chunk.rs
@@ -194,7 +194,7 @@ impl EcmascriptBrowserEvaluateChunk {
         let mut code = code.build();
 
         if let MinifyType::Minify { mangle } = this.chunking_context.await?.minify_type() {
-            code = minify(&code, source_maps, mangle)?;
+            code = minify(code, source_maps, mangle).await?;
         }
 
         Ok(code.cell())
diff --git a/turbopack/crates/turbopack-ecmascript/Cargo.toml b/turbopack/crates/turbopack-ecmascript/Cargo.toml
@@ -44,6 +44,7 @@ turbopack-resolve = { workspace = true }
 turbopack-swc-utils = { workspace = true }
 url = { workspace = true }
 urlencoding = { workspace = true }
+rayon = { workspace = true }
 
 swc_core = { workspace = true, features = [
   "ecma_ast",
diff --git a/turbopack/crates/turbopack-ecmascript/src/minify.rs b/turbopack/crates/turbopack-ecmascript/src/minify.rs
@@ -31,7 +31,18 @@ use turbopack_core::{
 use crate::parse::generate_js_source_map;
 
 #[instrument(level = Level::INFO, skip_all)]
-pub fn minify(code: &Code, source_maps: bool, mangle: Option<MangleType>) -> Result<Code> {
+pub async fn minify(code: Code, source_maps: bool, mangle: Option<MangleType>) -> Result<Code> {
+    let (tx, rx) = tokio::sync::oneshot::channel();
+
+    rayon::spawn(move || {
+        let result = minify_inner(code, source_maps, mangle);
+        tx.send(result).unwrap();
+    });
+
+    rx.await.unwrap()
+}
+
+fn minify_inner(code: Code, source_maps: bool, mangle: Option<MangleType>) -> Result<Code> {
     let source_maps = source_maps
         .then(|| code.generate_source_map_ref())
         .transpose()?;
@@ -139,8 +150,8 @@ pub fn minify(code: &Code, source_maps: bool, mangle: Option<MangleType>) -> Res
                 src_map_buf,
                 Some(original_map),
                 // We do not inline source contents.
-                // We provide a synthesized value to `cm.new_source_file` above, so it cannot be
-                // the value user expect anyway.
+                // We provide a synthesized value to `cm.new_source_file` above, so it cannot
+                // be the value user expect anyway.
                 false,
             )?),
         );
diff --git a/turbopack/crates/turbopack-nodejs/src/ecmascript/node/content.rs b/turbopack/crates/turbopack-nodejs/src/ecmascript/node/content.rs
@@ -78,7 +78,7 @@ impl EcmascriptBuildNodeChunkContent {
         let mut code = code.build();
 
         if let MinifyType::Minify { mangle } = this.chunking_context.await?.minify_type() {
-            code = minify(&code, source_maps, mangle)?;
+            code = minify(code, source_maps, mangle).await?;
         }
 
         Ok(code.cell())

Original file line number	Diff line number	Diff line change
`@@ -128,7 +128,7 @@ impl EcmascriptBrowserChunkContent {`
`128`	`128`	`let mut code = code.build();`
`129`	`129`
`130`	`130`	`if let MinifyType::Minify { mangle } = this.chunking_context.await?.minify_type() {`
`131`		`- code = minify(&code, source_maps, mangle)?;`
	`131`	`+ code = minify(code, source_maps, mangle).await?;`
`132`	`132`	`}`
`133`	`133`
`134`	`134`	`Ok(code.cell())`
Original file line number	Diff line number	Diff line change
`@@ -194,7 +194,7 @@ impl EcmascriptBrowserEvaluateChunk {`
`194`	`194`	`let mut code = code.build();`
`195`	`195`
`196`	`196`	`if let MinifyType::Minify { mangle } = this.chunking_context.await?.minify_type() {`
`197`		`- code = minify(&code, source_maps, mangle)?;`
	`197`	`+ code = minify(code, source_maps, mangle).await?;`
`198`	`198`	`}`
`199`	`199`
`200`	`200`	`Ok(code.cell())`
Original file line number	Diff line number	Diff line change
`@@ -78,7 +78,7 @@ impl EcmascriptBuildNodeChunkContent {`
`78`	`78`	`let mut code = code.build();`
`79`	`79`
`80`	`80`	`if let MinifyType::Minify { mangle } = this.chunking_context.await?.minify_type() {`
`81`		`- code = minify(&code, source_maps, mangle)?;`
	`81`	`+ code = minify(code, source_maps, mangle).await?;`
`82`	`82`	`}`
`83`	`83`
`84`	`84`	`Ok(code.cell())`