configuration store

[jaytaph]

I want to be able to configure all settings through an cobfiguration store at gosub://config

This setup should show all configration parameters that are available in the engine, useragent en other components.

User should be able to see which config values have changed (bold) and should be able to reset

A quick filter should be available

Maybe import/export to json

Each config setting should consist of a clear helptext with what it is for.

[jaytaph]

There are multiple components in the system that can rely on configuration settings.

For instance, the user-agent itself can be customized with settings (think about user-agent CSS settings)... but components like the network/dns resolver would like to know if it needs to use a local resolver, doh, dnssect etc..

we can pass these options manually, but it would become a bit like prop-drilling in my opinion. Instead, we could have the store as a global dependency which all components can use.

Since this is behind an interface, the implementation of the component store is not important right now. A simple text file will suffice for the time being.

This setup will also allow to easily test different integration tests as we simply need to define a store with the correct settings in-memory and pass this to the given components.

[jaytaph]

Another thing is where we actually add settings.

Do we have a configuration store that holds settings for all components available (so if we want to use a setting: dns.foobar.enabled in the dns component, do we need to add this setting to the configuration store, or does the dns component somehow publish this setting back to the configuration store?

I'd reckon the first option. This means that there is a large store of settings at a single point. It also means that it would be harder to get rid of obsolete settings, as we must check each component to see if the setting is still used.

(we might internally keep track on when a setting has been called by the configuration store, this could provide a way to detect unused configuration settings, but it's a bit of overhead that we add (we might be able to add this to a configuration flag as well).

[emwalker]

It also means that it would be harder to get rid of obsolete settings, as we must check each component to see if the setting is still used.

This might be easier if each setting is assigned to a constant in the code rather than referencing a string literal. That way rust-analyzer could detect whether the constant is in use.