Bridge Substrate Pallet

Overview

The Bridge Pallet represents the bridge in XP.network blockchain. It is responsible for communicating the bridge-related events and transactions to the bridge relay validators and submitting the transactions on the XP.network blockchain. It uses the ERC-1155 compatible pallet for operating fungible and non-fungible tokens.

Executing transactions in XP.network

The LocalAction enum contains the definitions for the local transactions.

#[derive(Encode, Decode, RuntimeDebug, Clone, PartialEq)]
pub enum LocalAction<T: Config> {
    ...
}

Available local transactions

1. Unfreezing the locked fungible & non-fungible tokens to a designated account in XP.network

2. Transfering wrapped foreign fungible & non-fungible tokens

3. Calling the functions of other smart contracts

Validators related actions

1.Checks whether the transaction was signed by a validator and otherwise returns an error.

    #[inline]
    fn ensure_validator(acc: &T::AccountId) -> Result<(), Error<T>> {
        if !Validators::<T>::contains_key(acc.clone()) {
            return Err(Error::<T>::Unauthorized)
        }
        Ok(())
    }

2.Collects the validators' signatures

action.validators.insert(validator);

3.Calculates the BFT threshold

let validator_cnt = ValidatorCnt::<T>::get().unwrap();
        if action.validators.len() == ((2./3.)*(validator_cnt as f64)) as usize + 1 {
            ret = Ok(true);
}

4.Keeps track of executed transactions by assigning them a number incremented by one to the last executed transactions.

fn action_inc() -> ActionId {
        let action = <LastActionId<T>>::get().unwrap();
        <LastActionId<T>>::put(action+1);
        return action;
    }