rmrk-team
Improve nesting / recursive calls
Currently there few places utilising unbound recursion ( ie lookup_root_owner ).
In order to follow best practices and implement proper benchmarking we need to bound recursive calls ( ideally avoid them in favour of loops ).
Proposed improvement is to integrate concept of budgets, as seen in Unique Network example
We can check the Budget trait defined here. This will allow for the caller to create a Budget for a call and define a Value for the number of calls allowed for an owner lookup.
Example:
// NESTING_BUDGET could be a configurable runtime trait or a StorageValue
let budget = budget::Value::new(NESTING_BUDGET);
let nft_owner = <pallet_rmrk_core::Pallet<T>>::lookup_root_owner(collection_id, nft_id, &budget).map_err(|_| <Error<T>>::Error)?;
Possible change to lookup_root_owner would move to a loop that calls consume on the Budget every iteration to ensure that the Budget throws an Error on a deeply nested NFT. This can work as a temporary workaround, but I'd be interested in other ideas on how to handle this.
