feat: add memory to app.getAppMetrics() (#18831)

lib/browser/api/app.ts

@@ -1,3 +1,4 @@
+import * as fs from 'fs'
 import * as path from 'path'
 
 import { deprecate, Menu } from 'electron'
@@ -66,6 +67,43 @@ if (process.platform === 'darwin') {
   app.dock!.getMenu = () => dockMenu
 }
 
+if (process.platform === 'linux') {
+  const patternVmRSS = /^VmRSS:\s*(\d+) kB$/m
+  const patternVmHWM = /^VmHWM:\s*(\d+) kB$/m
+
+  const getStatus = (pid: number) => {
+    try {
+      return fs.readFileSync(`/proc/${pid}/status`, 'utf8')
+    } catch {
+      return ''
+    }
+  }
+
+  const getEntry = (file: string, pattern: RegExp) => {
+    const match = file.match(pattern)
+    return match ? parseInt(match[1], 10) : 0
+  }
+
+  const getProcessMemoryInfo = (pid: number) => {
+    const file = getStatus(pid)
+
+    return {
+      workingSetSize: getEntry(file, patternVmRSS),
+      peakWorkingSetSize: getEntry(file, patternVmHWM)
+    }
+  }
+
+  const nativeFn = app.getAppMetrics
+  app.getAppMetrics = () => {
+    const metrics = nativeFn.call(app)
+    for (const metric of metrics) {
+      metric.memory = getProcessMemoryInfo(metric.pid)
+    }
+
+    return metrics
+  }
+}
+
 // Routes the events to webContents.
 const events = ['login', 'certificate-error', 'select-client-certificate']
 for (const name of events) {