feat: workspace-concurrency based on cores amount (#3574)

.changeset/mean-insects-leave.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/config": minor
+---
+
+Add `workspace-concurrency` based on CPU cores amount, just set `workspace-concurrency` as zero or negative, the concurrency limit is set as `max((amount of cores) - abs(workspace-concurrency), 1)`

packages/config/src/concurrency.ts

@@ -0,0 +1,13 @@
+import { cpus } from 'os'
+
+export function getWorkspaceConcurrency (option: number | undefined): number {
+  if (typeof option !== 'number') return 4
+
+  if (option <= 0) {
+    // If option is <= 0, it uses the amount of cores minus the absolute of the number given
+    // but always returning at least 1
+    return Math.max(1, cpus().length - Math.abs(option))
+  }
+
+  return option
+}

packages/config/src/index.ts

@@ -19,6 +19,7 @@ import {
   ConfigWithDeprecatedSettings,
   UniversalOptions,
 } from './Config'
+import { getWorkspaceConcurrency } from './concurrency'
 
 export { Config, UniversalOptions }
 
@@ -447,6 +448,8 @@ export default async (
     }
   }
 
+  pnpmConfig.workspaceConcurrency = getWorkspaceConcurrency(pnpmConfig.workspaceConcurrency)
+
   return { config: pnpmConfig, warnings }
 }
 

packages/config/test/concurrency.test.ts

@@ -0,0 +1,30 @@
+import { cpus } from 'os'
+import { getWorkspaceConcurrency } from '../lib/concurrency'
+
+const hostCores = cpus().length
+
+test('default workspace concurrency', () => {
+  const n = getWorkspaceConcurrency(undefined)
+
+  expect(n).toBe(4)
+})
+
+test('get back positive amount', () => {
+  expect(getWorkspaceConcurrency(5)).toBe(5)
+})
+
+test('match host cores amount', () => {
+  const n = getWorkspaceConcurrency(0)
+
+  expect(n).toBe(hostCores)
+})
+
+test('host cores minus X', () => {
+  const n1 = getWorkspaceConcurrency(-1)
+
+  expect(n1).toBe(Math.max(1, hostCores - 1))
+
+  const n2 = getWorkspaceConcurrency(-9999)
+
+  expect(n2).toBe(1)
+})