Webradio - High CPU usage by web browser

andfor

HI,

I have just noticed a strange issue when running Rune UI through a web-browser. If I am listening to a radio station the web browser will sometimes show nearly 25% CPU utilization. This happens when the browser is open on the Playback page. For most stations, If I refresh the UI this drops to around 2%.

There are some stations that won't display the radio 'album art', just the place-holder Rune symbol. Refreshing the UI on these stations does nothing, CPU still 25%.

I am using Firefox. I am using a modified version of Rune 0.4b on an Rpi3. I have altered the UI files to my own liking, mostly cosmetic, but I did change the behaviour of selecting radio stations to a single-click 'Add, Replace and Play' (see: #5746

Any help tracking down the cause of this would be appreciated.

Many thanks.

hondagx35

Hi andfor,

please open the developer console on your Firefox browser and check for errors.

Frank

andfor

***EDIT: I have edited this question to include more information.

Hi Frank,

I have had a look at the developer console and have some more information about how this error occurs. Here's the sequence:

1) Select webradio stream and this error warning occurs:

Empty string passed to getElementById().
jquery-2.1.0.min.1424619780.js:2:23965[/quote]

2) Navigate to 'Playback' screen. Again:

Empty string passed to getElementById().
jquery-2.1.0.min.1424619780.js:2:23965

3) I have noticed that high CPU usage occurs when the track progress wheel starts filling up as in the image below:

4) BUT.... If I click anywhere on the blue progress wheel the CPU usage drops to nothing and i get the following error:

4) If I select another radio station, CPU usage shoots back up again on navigating to the 'Playback' screen.

5) Reloading the webpage causes the CPU to return to normal and the progress wheel is now greyed out as below:

...and I get this error:

Source map error: SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data
Resource URL: http://192.168.0.6/js/vendor/hammer.min.1518951835.js
Source Map URL: hammer.min.js.map

I hope that's enough information to reproduce the problem or at least to help me try and fix it on my installation.

Thanks for the help!

andfor

Hi,

I was just wondering if there was any opinion as to what is happening here? The problem seems to be with navigating to the Playback screen using the 'Playback' button along the bottom bar. This doesn't reload the page (like selecting 'Playback' from the dropdown menu does) so my best guess is that it's something to do with the progress wheel attempting to treat an infinite radio stream like a music file that has a finite length.

Anyway, I don't have the technical proficiency to follow the errors and debug this so any help or insight would be welcome.

Many thanks

andfor

No ideas?

I realise nobody wants to chase rabbits down holes on my behalf, but any pointers as to what might be happening would be appreciated. Where do I start? And does anyone else see the same behaviour? Is it present on a stock install? (I have modified mine).

It's not a huge deal because I can just reload the page every time I select a radio stream to bring down the CPU usage, but that is a bit annoying.

Thanks again.

hondagx35

Hi andfor,

i can reproduce your issue.

I will take a look at it as soon as possible.

Frank

andfor

Thanks Frank. Good to know it's not just me.

irishwill2008

I just had similar issue but pointing to: bootstrap-select.min

I fixed this by removing both

//# sourceMappingURL=bootstrap-select.js.map

/*! etc code

which is the commented out code in the file. This fixed my issue.

Perhaps there is comments in the hammer file? My version of rune doesnt have a hammer file to check for you