Enhance thumbnail downloading / Download all thumbnails in one folder / smart cache size

[tobiasKaminsky]

Download all thumbnails in one folder with one click -> three dots menu.
@jancborchardt should there be a notification for this which displays the progress?

[jancborchardt]

That should be done automatically on entering the folder and not require an extra action. Or which thumbnails do you refer to?

[Spacefish]

No, Thumbnails are only downloaded once you scroll down.. the disk cache has a limited size 8 Mbytes as far as I remember and the purge policy is LRU. There might be folders which contain more than 8 MByte of thumbnails! Even if not, once you reach the 8 mb threshold, thumbs from other folders are evicted from the cache.

[tobiasKaminsky]

This is a tricky one, I think...
As @Spacefish pointed out we have a limited (currently 10mb) cache with LRU.
In the next version it will be possible to resize the cache to any value.

The reason for the idea of downloading all thumbnails is that otherwise one have to scroll slowly through all images in one folder.
@jancborchardt proposal is problematic when you are on a limited network and it takes up all network bandwith.

With these both restrictions (bandwith and cache size) I thought it must be an optional action that the user have to choose (and therefore really want it).

PS: A thumbnail is ~15kb.

[strugee]

We should always download all thumbnails on (non-metered?) WiFi. Otherwise I think the best design would be to download all thumbnails on screen, and a certain number off the bottom and top, in case the user scrolls.

@jancborchardt and others, thoughts?

[AndyScherzinger]

Download behavior

How about making it depend on the connection:

• metered wifi / cellular network: keep the actual download behavior for thumbnails
• unmetered wifi: download them all

Cache size

Could we make this dynamic and choose a cache size during the first start of the app and maybe every once in a while?

• calculate cache size as: 5% of the available space but max 100MB?
• recalculate cache size: If possible check the available space every 4 weeks and recalculate as described above

Just an idea. So.. @ all : Would this be possible? And would this make sense?

[strugee]

@AndyScherzinger sounds similar to what I said; +1

[AndyScherzinger]

yes, I basically summed up the post and comments :)

[jancborchardt]

@strugee @AndyScherzinger sounds good. No options, just automatic and fitting behavior. :)

[Spacefish]

I wouldn't limit the Cachesize to 100mb. I would go with 5% and only if the remaining free storage is <80% of the total device storage limit it to the said 100mb.
If you look at the Google Fotos App, it will take multiple 100mb of Thumbs.

[AndyScherzinger]

@jancborchardt @tobiasKaminsky I think the simpler version as described by @Spacefish by simply going for 5% as long as a certain device storage is still available would be best. I would change it a little though and say:

• >=40% of the total storage available: set cache size to 5% of total storage size of the device
• < 40% of the total storage available: set cache size to 10% of the remaining space available but at least 20MByte (which still gives you space for >1300 image thumbnails)

sounds a bit complicated but should work nicely :) What do you think @tobiasKaminsky ? Hope it is not to over-engineered 😋

[tobiasKaminsky]

Download behaviour is fine for me. But we have to ensure that it does not delay any other task, e.g. downloading a file or fetching a resized image.

Cache size: I would not set any limit, but increase it dynamically.
The cache size will also be adjustable with #144
So the current maximum should be displayed there with an information that it is increasing automatically.
If a user sets a value this will be a hard maximum which has to be respected. If it is too low (according to @AndyScherzinger metric or any else) there should be a warning and a proper proposal.

[AndyScherzinger]

There should imho also be a hard maximun, simply to be a good citizen on the phone. 😃

[tobiasKaminsky]

How are other apps handling this? Dropbox, etc?

[AndyScherzinger]

I don't know since this is an internal implementation, blackbox... :(

[tobiasKaminsky]

Na, I meant just be downloading lots of dropbox content and see the cache size ;)
I do not have a dropbox...

[jancborchardt]

@tobiasKaminsky just create a fakeaccount for testing purposes, that’s always recommended to check what others are doing. :)

[tobiasKaminsky]

I have a new idea:
Initial sync: Based on the timestamp of folder (and its content) we can go from new to old and download all thumbnails. This can stop when cache limit is reached. So we make sure that the most recent images have a thumbnail.

Regular sync: Based on the same logic of above we can do a regular sync. As we have a "least recently used" cache policy all new thumbnails and most often used thumbnails should stay in cache.

Both can be done automatically via a JobScheduler with the limitation "wlan" and "charging".

[strugee]

@tobiasKaminsky that sounds like a wonderful idea. We should still implement the previously discussed behavior though, when actively browsing to a folder.

[jancborchardt]

Good call! So the previously mentioned logic should be used, preferring the generation of previews for recently modified files. :)