From c10311cc74937b81f48ff2d8508fac41b8c5d249 Mon Sep 17 00:00:00 2001
From: easrng <me@easrng.net>
Date: Mon, 9 Oct 2023 13:02:46 -0600
Subject: [PATCH] feat(terser): use os.availableParallelism if possible

---
 package.json                       |  2 +-
 packages/terser/src/worker-pool.ts | 12 +++++++++---
 pnpm-lock.yaml                     | 22 ++++++++++++++++------
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/package.json b/package.json
index b6203e6d4..4d2580baf 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
     "@ava/babel": "2.0.0",
     "@rollup/plugin-typescript": "^9.0.1",
     "@types/conventional-commits-parser": "^3.0.2",
-    "@types/node": "14.18.30",
+    "@types/node": "20.8.4",
     "@types/semver": "^7.3.7",
     "@types/source-map-support": "^0.5.4",
     "@types/yargs-parser": "^20.2.1",
diff --git a/packages/terser/src/worker-pool.ts b/packages/terser/src/worker-pool.ts
index d061e5d69..afc5e7829 100644
--- a/packages/terser/src/worker-pool.ts
+++ b/packages/terser/src/worker-pool.ts
@@ -1,6 +1,6 @@
 import { AsyncResource } from 'async_hooks';
 import { Worker } from 'worker_threads';
-import { cpus } from 'os';
+import os from 'os';
 import { EventEmitter } from 'events';
 
 import serializeJavascript from 'serialize-javascript';
@@ -40,8 +40,14 @@ export class WorkerPool extends EventEmitter {
   constructor(options: WorkerPoolOptions) {
     super();
 
-    // cpus() can return [] on some platforms, and we always need at least 1 worker
-    this.maxInstances = options.maxWorkers || cpus().length || 1;
+    if (options.maxWorkers) {
+      this.maxInstances = options.maxWorkers;
+    } else if (typeof os.availableParallelism === 'function') {
+      this.maxInstances = os.availableParallelism();
+    } else {
+      // cpus() can return [] on some platforms, and we always need at least 1 worker
+      this.maxInstances = os.cpus().length || 1;
+    }
     this.filePath = options.filePath;
 
     this.on(freeWorker, () => {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 0102b96b7..66ac40dc1 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -18,8 +18,8 @@ importers:
         specifier: ^3.0.2
         version: 3.0.2
       '@types/node':
-        specifier: 14.18.30
-        version: 14.18.30
+        specifier: 20.8.4
+        version: 20.8.4
       '@types/semver':
         specifier: ^7.3.7
         version: 7.3.12
@@ -85,7 +85,7 @@ importers:
         version: 0.5.21
       ts-node:
         specifier: 10.9.1
-        version: 10.9.1(@types/node@14.18.30)(typescript@4.8.4)
+        version: 10.9.1(@types/node@20.8.4)(typescript@4.8.4)
       tsconfig-paths:
         specifier: ^3.9.0
         version: 3.14.1
@@ -2733,6 +2733,12 @@ packages:
     resolution: {integrity: sha512-vQAnaReSQkEDa8uwAyQby8bYGKu84R/deEc6mg5T8fX6gzCn8QW6rziSgsti1fNvsrswKUKPnVTi7uoB+u62Mw==}
     dev: true
 
+  /@types/node@20.8.4:
+    resolution: {integrity: sha512-ZVPnqU58giiCjSxjVUESDtdPk4QR5WQhhINbc9UBrKLU68MX5BF6kbQzTrkwbolyr0X8ChBpXfavr5mZFKZQ5A==}
+    dependencies:
+      undici-types: 5.25.3
+    dev: true
+
   /@types/normalize-package-data@2.4.1:
     resolution: {integrity: sha512-Gj7cI7z+98M282Tqmp2K5EIsoouUEzbBJhQQzDE3jSIRk6r9gsz0oUokqIUR4u1R3dMHo0pDHM7sNOHyhulypw==}
     dev: true
@@ -6413,7 +6419,7 @@ packages:
     dependencies:
       lilconfig: 2.0.6
       postcss: 8.4.17
-      ts-node: 10.9.1(@types/node@14.18.30)(typescript@4.8.4)
+      ts-node: 10.9.1(@types/node@20.8.4)(typescript@4.8.4)
       yaml: 1.10.2
     dev: true
 
@@ -7605,7 +7611,7 @@ packages:
     resolution: {integrity: sha512-Y/arvbn+rrz3JCKl9C4kVNfTfSm2/mEp5FSz5EsZSANGPSlQrpRI5M4PKF+mJnE52jOO90PnPSc3Ur3bTQw0gA==}
     dev: false
 
-  /ts-node@10.9.1(@types/node@14.18.30)(typescript@4.8.4):
+  /ts-node@10.9.1(@types/node@20.8.4)(typescript@4.8.4):
     resolution: {integrity: sha512-NtVysVPkxxrwFGUUxGYhfux8k78pQB3JqYBXlLRZgdGUqTO5wU/UyHop5p70iEbGhB7q5KmiZiU0Y3KlJrScEw==}
     hasBin: true
     peerDependencies:
@@ -7624,7 +7630,7 @@ packages:
       '@tsconfig/node12': 1.0.11
       '@tsconfig/node14': 1.0.3
       '@tsconfig/node16': 1.0.3
-      '@types/node': 14.18.30
+      '@types/node': 20.8.4
       acorn: 8.8.0
       acorn-walk: 8.2.0
       arg: 4.1.3
@@ -7746,6 +7752,10 @@ packages:
       which-boxed-primitive: 1.0.2
     dev: true
 
+  /undici-types@5.25.3:
+    resolution: {integrity: sha512-Ga1jfYwRn7+cP9v8auvEXN1rX3sWqlayd4HP7OKk4mZWylEmu3KzXDUGrQUN6Ol7qo1gPvB2e5gX6udnyEPgdA==}
+    dev: true
+
   /unicode-canonical-property-names-ecmascript@1.0.4:
     resolution: {integrity: sha512-jDrNnXWHd4oHiTZnx/ZG7gtUTVp+gCcTTKr8L0HjlwphROEW3+Him+IpvC+xcJEFegapiMZyZe02CyuOnRmbnQ==}
     engines: {node: '>=4'}