System Pressure Monitor
Get informed about your system compute pressure. Under the hood it utilizes the Compute Pressure API with source "CPU".
Available since EyesonJS v1.9.3
Works currently only in Chromium based browsers (Chrome, Edge, Opera, etc.) since version 125.
See caniuse.com.
import { FeatureDetector, SystemPressureMonitor } from 'eyeson'
FeatureDetector.canMonitorSystemPressure()
const monitor = new SystemPressureMonitor({ sampleInterval })
monitor.onUpdate(state => {
console.log(`cpu pressure: ${state}`)
})
monitor.offUpdate(fn) // specific function
monitor.offUpdate() // clear all
await monitor.start()
monitor.stop() // call stop for a pause and start later again
monitor.destroy()
Pressure states
nominal
The conditions of the target device are at an acceptable level with no noticeable adverse effects on the user.
fair
Target device pressure, temperature and/or energy usage are slightly elevated, potentially resulting in reduced battery-life, as well as fans (or systems with fans) becoming active and audible. Apart from that the target device is running flawlessly and can take on additional work.
serious
Target device pressure, temperature and/or energy usage is consistently highly elevated. The system may be throttling as a countermeasure to reduce thermals.
critical
The temperature of the target device or system is significantly elevated and it requires cooling down to avoid any potential issues.
Source: https://w3c.github.io/compute-pressure/#pressure-states
Sample Interval
The sample interval is the requested sampling interval expressed in milliseconds. It defaults to 1000ms. We recommend setting it to some seconds to avoid many quick switches.
Permission
FeatureDetector.canMonitorSystemPressure() also performs a permission check.
If you're running SystemPressureMonitor inside an IFrame, make sure to add compute-pressure to the allow list.
See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Permissions-Policy/compute-pressure for more information.
Eyeson IFrame API already includes the compute-pressure permission.