If you're like me, you love Darktable but find it quite slow to use for navigating images. Darktable comes with a built-in caching system, but it seems to not want to generate useful thumbnail caches at import time (like the manual says it's supposed to). This LUA plugin is designed to bridge this gap by automatically generating high-quality image thumbnail cache for all images at the time they're imported.

Use the "Install/Update" action in the "script manager" tab of the lighttable view to enter the path to this repository - "https://github.com/lily-mara/darktable-autocache", and write "autocache" as the category name (this is not significant from a technical perspective, but it is useful for your own organization). Next, click the "install additional scripts" button.

After this, you should be taken to a view showing your newly installed script with a box that says "autocache stopped". By default, Darktable does not run plugins immediately after install, you need to manually enable them. Click this box and the text should change to "autocache started" and you should see a toast message reading "Loaded autocache/autocache".

You also need to make sure that your settings are compatible with this plugin. You must enable the "processing > cpu / gpu / memory > enable disk backend for full preview cache" setting for this plugin to have its full effect. Enabling this plugin without enabling that toggle could have unintended performance issues.

At this point, you're all set!

Once enabled, the plugin should all but disappear into the background. As you import new images, the plugin will automatically run in the background, caching image previews and showing you a progress bar of the process.

Enabling this plugin has very clear benefits and costs.

You should notice that newly imported images are much faster to navigate in the lighttable view after the autocache process has completed.

Importing images will now burn more compute resources (CPU or maybe GPU depending on your setup) because in addition to the normal import flow, you will also be running the intensive preview generation step ahead of time.

The "full" import process (actual import + autocache) will now take longer than before, for the same reason as above. You should be able to browse your newly imported images while autocache is running, but you will not see the same performance gains as you will once it's completed.

Disk usage from caching will increase significantly. Storing high-quality image previews is not free from a storage perspective. For my library of ~8k RAW images, the full cache takes about 15GiB of disk space. If storage is at a premium for you, this plugin may not be ideal.

This plugin doesn't invent anything. All of the functionality that this plugin performs is built-in to Darktable, it's just not done automatically. There are a few ways to accomplish what this plugin does without installing it.

1. After importing images, page through every image you've imported. This forces Darktable to generate and store preview files.
2. Run darktable-generate-cache -m 6 after each import. This generates the same quality preview files that this plugin does, but it doesn't allow you to use Darktable while the generation is happening and it's not automatic.