op env's get_by_path return value different from root_state_accessor_stub's get_object_by_path

[weiqiushi]

path op env's get_by_path has return value BuckyResult<Option>
it shows when path not exists, it may return Ok(None)

but root_state_accessor_stub's get_object_by_path function has return value BuckyResult

I think when path not exists, it will return BuckyErrorCode::NotFound?

Is there a need to make the return values of these two functions same?

[lurenpluto]

This should be formed by some historical reasons, in the rpc interface, if the target does not exist, either return None, or NotFound error

get_object_by_path

For accessor.get_object_by_path method, this internal is integrated with the root-state and non interfaces, so at the beginning of the design, the counterpart is non.get_object (because the semantics are closer), and non.get_object is a very old interface, at the beginning of the design is designed to return NotFound when the target object does not exist

get_object_by_path's target does not exist, but also contains two layers of meaning

• The corresponding path does not exist on the root-state
• The object_id corresponding to root-state/{path}, but the corresponding object does not exist

op-env's get relate methods

op-env is designed to add, delete, check and change global-state (root-state + local-cache), so if the path does not exist, it is more friendly to return None directly, against the interface of some common data structures, such as the get interface of rust's HashMap

https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.get