JSI & Reactive Options

[swabbass]

Motivation

Today, our API uses ReactNative "Bridge" in order to process RNN commands, and that is a 2 part topic that can be described as follow:

• Native Thread and JS thread asynchronous messaging system.
• Options, mainly about parsing from RN maps, and memory usage.

We had a discussion about these topics and to move our library forward to be more modern, clean, and more importantly fast.

Feel free to comment, share your thoughts, maybe suggestions, changes.

JSI

Consider using JavaScriptInterface in order to make RNN commands synchronous, hence, "immediate" access from JS thread to Native threads.

There are a couple of examples of how it might being done.

Inspired by Reanimated 2.0 SharedValue,
which is in a simplified way, holds the JS Object to Native object parsing and caching, providing worklets that acts as a wrapper to run a function in the native side and running a native function in the js thread, synchronously, and using the parsing part to manage the arguments and more cool stuff, thx to C++;

That enables us on android to access native code faster via JSI & NDK code, and on iOS just to call functions and declare options natively.

Reactive Options

Options can be reactive in a way when calling mergeOptions, or any other command that has options, we should change the only attributes without any unused extra objects, aside from those needed in the process, and aggregate the changes to subscribed views.

concepts:

• Each view controller subscribe to a set of options that it needs once.
• Using SharedValue for fast access.
• Keep options logic in C++, and share updates with the android/iOS ViewController once changes take place.

Added Value

Such change should have a clear goal on how this awesome lib should go, and it should be:

• Faster.
• More Memory friendly.
• Easly extendable/upgradable.

Workplan

• Intgerating JSI dependencies.
• Test JSI integrability.
• Add JSI ready inner JS API, as an opt-in, feature.
• Add platform tests that dictate the wanted synchronous reactive options behaviour.
• Define options logic and cache on the native side (JSI).
• Intercommunicate between [Android, iOS] and C++, define reactive behaviour.
• Get the lib ready for devs preview, alpha, beta, or snapshot.
• Check for feedback and issues.
• Improve until no major issues.
• Bump next major.

CC: @yogevbd