reset neuron data on dereg

[andreea-popescu-reef]

reviving: #522

Description

On neuron registration the trust, emission, consensus, incentive, dividends values as well as axon info associated with the assigned neuron_uid are inherited from the previous neuron. Thus for the first few blocks after registration these values will be wrong, then reset to zero and then get populated with the correct values for the newly registered neuron. This change resets these values on neuron registration.

[distributedstatemachine]

@andreea-popescu-reef also changed the base against devnet-ready , so you need to resolve conflicts , or fork off devnet-ready

[distributedstatemachine]

Can we optimise this by reducing the number of storage / writes , and number of function calls ?

pub fn clear_neuron(netuid: u16, neuron_uid: u16) {
    let neuron_index: usize = neuron_uid.into();
    let default_value = 0;

    for storage in &mut [
        &mut Emission::<T>::get(netuid),
        &mut Trust::<T>::get(netuid),
        &mut Consensus::<T>::get(netuid),
        &mut Incentive::<T>::get(netuid),
        &mut Dividends::<T>::get(netuid),
    ] {
        set_element_at(storage, neuron_index, default_value);
    }
}

[andreea-popescu-reef]

that does not quite work as the vectors have different int types

[andreea-popescu-reef]

it's the same number of calls to the set_element_at. is there much difference between get vs mutate calls? aren't they compiled to similar things?

[andreea-popescu-reef]

anyway made the change

[andreea-popescu-reef]

reverted - that does not work

[camfairchild]

Can we not just clear the netuid prefix? Or is that the same runtime?

[andreea-popescu-reef]

it does not modify the vector - &mut Emission::::get(netuid) just gives back the value & StorageMap does not have a way to get a mut ref to the value

[andreea-popescu-reef]

rebased this pr