Use commit hook to update props on Fabric

[tomekzaw]

Summary

This draft PR introduces a new approach towards updating layout props on Fabric that uses UIManagerCommitHook. Previously, we would keep a registry of most recent ShadowNodes. Each time RN or Reanimated cloned a ShadowNode, we would retrieve the most recent version of it from the registry as well as store the new copy. Obviously, this required synchronization at the level of each cloneNode call so rendering large trees was slow. The new approach stores all most recent props of animated components in PropsRegistry and applies them on each RN render using ReanimatedCommitHook all at once which improves the performance significantly.

Changes:

• Removed ReanimatedUIManagerBinding
• Added ReanimatedCommitHook
• Converted NewestShadowNodesRegistry into PropsRegistry
• Converted _removeShadowNodeFromRegistry into _removeFromPropsRegistry
• Updated initialization flow

Requires:

• Run commit hooks before layout calculation facebook/react-native#36216 (merged, thanks @sammy-SC, released in 0.72.0-rc.0)

Things to consider:

• Commit an identical tree and let ReanimatedCommitHook handle all updates instead of calling isThereAnyLayoutProp, enqueuing update in operationsInBatch_ and updating lastReanimatedRoot but modifying only necessary ShadowNodes?
• Copy propsRegistry.map_ in ReanimatedCommitHook to prevent locking the UI thread while the background thread runs the commit hook?

Detected problems:

• If calculating layout of RN tree takes more than one frame, Reanimated will skip the commit before RN can commit its own tree and the problem still persists
• If calculating layout of RN tree takes more than one frame, Reanimated will run the animations in the meantime and finally RN will mount outdated tree
• When there's just a few layout props changes and many non-layout props changes (e.g. emoji shower and progress bar), we still apply all changes via commit (this is to enforce UI consistency).
• On each RN render (even if only one component is changed) we need to apply all changes from the whole PropsRegistry (which contains all currently mounted animated components).

Review

Since this PR affects 31 files, it is recommended to review the commits one-by-one.

Test plan

Launch FabricExample and open the following examples: chessboard, width, ref

[kmagiera]

Looks good. Would be even better if you could write 2-3 sentences in the description to explain how this new approach works.

[kmagiera]

Do we need to retain commitHook as a class member here? Looks like it is not being used except from passing it to uimanager. Same applies in NativeProxy implementation for Android

[tomekzaw]

We need to store it because React Native's UIManager keeps a vector of raw pointers (see here).