Jukebox queue length and minimum

[greku]

I feel like the Jukebox queue minimum length is too small compared to its maximum value.
While listening to music, I saw the Jukebox emptying, 20, 15... and wondering whether there is a problem as I will soon run out of music...
Ideally, the Jukebox could remain filled to a constant level.
Maybe there is a good reason to refill only when it becomes almost empty ?

myMPD/src/compile_time.h.in

Lines 349 to 352 in fc17269

	#define JUKEBOX_INTERNAL_SONG_QUEUE_LENGTH 100 // length of the internal jukebox queue for songs
	#define JUKEBOX_INTERNAL_ALBUM_QUEUE_LENGTH 25 // length of the internal jukebox queue for albums
	#define JUKEBOX_INTERNAL_SONG_QUEUE_LENGTH_MIN 10 // length of the internal jukebox queue for songs
	#define JUKEBOX_INTERNAL_ALBUM_QUEUE_LENGTH_MIN 5 // length of the internal jukebox queue for albums

I have tested with the min set to 99 first, I didn't see any particular issue, it refills two songs at a time.
I have also tested with the min set to 100, it is a bit more scary, but seems to work fine too. (edit: actually not, see below discussion)

[jcorporation]

This is done for performance reasons. Filling the jukebox queue is resource intensive, that's the reason why it exists at all. It could be an option to make this setting configurable.

[greku]

OK, that makes sense then. I suppose that adding 90 songs to the jukebox is more efficient than adding 45 times 2 songs.
I'm not running on an embedded platform here.

Related to this, the Jukebox also doesn't fill until the queue would become empty. So I cannot see the Jukebox content before 10 seconds before it starts playing the Jukebox. I would also prefer that Jukebox is always filled as soon as mympd is launched ( if enabled).
But I also have some other start-up issues, that I still don't understand. I will recheck the manual and github history.

[john-]

As far as seeing the upcoming jukebox songs in advance of what you see in the queue: Have you seen Queue|Select view (upper left icon)|Jukebox? Those are the songs that are planned for the jukebox.

[greku]

Yes, of course, I'm checking there.
To reproduce this: if you have MPD + myMPD running, if I restart myMPD, the jukebox is empty and remains like that until the queue becomes empty ( I set Jukebox to keep queue length 1 song). ( but it also happens when I start the MPD and myMPD on boot of my system.)

[jcorporation]

This is the intended behavior.

[greku]

Could it be an idea to save the jukebox list and restore on start up ? It would not be empty then, and it will avoid having to regenerate it ?

[greku]

I have tested further, and with JUKEBOX_INTERNAL_SONG_QUEUE_LENGTH_MIN set to 100, there is an issue, when it refills the jukebox, the first song in the list is replaced by another one. I guess it is a side effect from the logic that updates the jukebox.
With 99, it works correctly.

[jcorporation]

The jukebox can maintain a fixed length of the MPD queue. This could be that what you try to achieve.

[greku]

Yes, that would be an alternative, but not yet ideal.
We prefer to keep only one item in the queue so that it is possible to add "priority" songs in the queue at any time.
I know it is possible to insert after the current playing one, but then they would not add after each other, but in reverse order.
Another idea would be to have a button to refill the jukebox on request.

[jcorporation]

Another idea would be to have a button to refill the jukebox on request.

This is a good idea #1483. I can also make the min. and max. jukebox queue length settings configurable #1484.

I am thinking also about the option to keep the jukebox queue between restarts.

[greku]

Now that we can manually request a refill of the jukebox, it can happen that someone requests a refill when the jukebox is filled to maximum - 1. In that case, the issue I mentioned earlier is happening (the first item is overwritten, and the added item is a constant same song).
I think to fix it it, this line needs to be corrected, replacing 0 by initial_length

myMPD/src/mympd_client/random_select.c

Line 282 in fc17269

: 0;

[jcorporation]

Yes, this fixes this.

It seems you use the jukebox feature more intense than most myMPD users.