Transaction Calculation
The math behind gas fee calculation on the VechainThor blockchain.
Blockchain networks often refer to transaction fees as gas. Gas refers to the unit that measures the amount of computation effort required to execute operations on the blockchain network. This is a fee that is paid by the transaction sender and received by the blockchain network validator.
The intrinsic gas for a transaction is the amount of the transaction used before any code runs. In other words, it is a constant "transaction fee" plus a fee for every byte of data supplied with the transaction.The gas in the transaction needs to be greater than or equal to the intrinsic gas used by the transaction.
- is the constant transaction fee 5,000
- There are two types of
- Regular transaction : 16,000
- Contract creation : 48,000
-
- is the number of bytes equal to zero within the data in theclause andthe number of bytes not equal to zero
The VechainThor blockchain transaction model is capable of containing clauses which allows a single transaction to carry out multiple tasks. Therefore, the total gas cost of the transaction needs to include all the clauses gas costs in the transaction.
The total gas,
, required for a transaction can be computed as:
- where
- There are two types of
- Regular transaction : 16,000
- Contract creation : 48,000
-
- is the number of bytes equal to zero within the data in theclause andthe number of bytes not equal to zero
- is the gas cost returned by the virtual machine for executing theclause.
The VechainThor blockchain allows for transaction-level proof of work (PoW) and converts the proved work into extra gas price that will be used by the system to generate more reward to the block generator, the Authority Masternode, that validates the transaction. In other words, users can utilize their local computational power to make their transactions more likely to be included in a new block.
In particular, the computational work can be proved through fields
Nonce
and BlockRef
in the transaction model. Let and
represent the values of the transaction fields
Nonce
and Gas
, respectively. We use to denote the number of the block indexed by transaction field
BlockRef
and the number of the block that includes the transaction. Let
denote the transaction without fields
Nonce
and Signature
, the transaction sender's account address,
the base gas price,
the hash function and
the recursive length prefix (RLP) encoding function.
The PoW,
, is defined as:
The extra gas price,
, is computed as:
with the following constraint
The VTHO reward for packing the transaction into a new block is computed as:
where
is the gas price coefficient and
the actual amount of gas used for executing the transaction.
From the above equations, we know that
- 1.Sinceis a valid block number,
BlockRef
must refer to an existing block, that is, it's value must equal the first four bytes of an existing block ID; - 2.The transaction must be packed into a block within the period of 30 blocks after block, or otherwise, the PoW would not be recognized by the system;
- 3.The extra gas pricecan not be greater than base gas price P.
The total gas price for the transaction sender is computed as:
and the total price for block generators as
Where
is the gas used by the transaction and
is the value of field
GasPriceCoef
(a value between 0-255) and the extra gas price converted from the proven local computational work.
It can be seen that the gas price used to calculate the transaction cost depends solely on the input gas-price coefficient while the reward for packing the transaction into a block varies due to the transaction-level proof-of-work mechanism.
Last modified 19d ago