54 lines
2.1 KiB
Markdown
54 lines
2.1 KiB
Markdown
|
<!--
|
||
|
|
order: 3
|
||
|
|
-->
|
||
|
|
|
||
|
|
# Begin block
|
||
|
|
|
||
|
|
The base fee is calculated at the beginning of each block.
|
||
|
|
|
||
|
|
## Base Fee
|
||
|
|
|
||
|
|
### Disabling base fee
|
||
|
|
|
||
|
|
We introduce two parameters : `NoBaseFee`and `EnableHeight`
|
||
|
|
|
||
|
|
`NoBaseFee` controls the feemarket base fee value. If set to true, no calculation is done and the base fee returned by the keeper is zero.
|
||
|
|
|
||
|
|
`EnableHeight` controls the height we start the calculation.
|
||
|
|
- If `NoBaseFee = false` and `height < EnableHeight`, the base fee value will be equal to `base_fee` defined in the genesis and the `BeginBlock` will return without further computation.
|
||
|
|
- If `NoBaseFee = false` and `height >= EnableHeight`, the base fee is dynamically calculated upon each block at `BeginBlock`.
|
||
|
|
|
||
|
|
Those parameters allow us to introduce a static base fee or activate the base fee at a later stage.
|
||
|
|
|
||
|
|
### Enabling base fee
|
||
|
|
|
||
|
|
To enable EIP1559 with the EVM, the following parameters should be set :
|
||
|
|
|
||
|
|
- NoBaseFee should be false
|
||
|
|
- EnableHeight should be set to a positive integer >= upgrade height. It defines at which height the chain starts the base fee adjustment
|
||
|
|
- LondonBlock evm's param should be set to a positive integer >= upgrade height. It defines at which height the chain start to accept EIP1559 transactions
|
||
|
|
|
||
|
|
|
||
|
|
### Calculation
|
||
|
|
|
||
|
|
The base fee is initialized at `EnableHeight` to the `InitialBaseFee` value defined in the genesis file.
|
||
|
|
|
||
|
|
The base fee is after adjusted according to the total gas used in the previous block.
|
||
|
|
|
||
|
|
```golang
|
||
|
|
parent_gas_target = parent_gas_limit / ELASTICITY_MULTIPLIER
|
||
|
|
|
||
|
|
if EnableHeight == block.number
|
||
|
|
base_fee = INITIAL_BASE_FEE
|
||
|
|
else if parent_gas_used == parent_gas_target:
|
||
|
|
base_fee = parent_base_fee
|
||
|
|
else if parent_gas_used > parent_gas_target:
|
||
|
|
gas_used_delta = parent_gas_used - parent_gas_target
|
||
|
|
base_fee_delta = max(parent_base_fee * gas_used_delta / parent_gas_target / BASE_FEE_MAX_CHANGE_DENOMINATOR, 1)
|
||
|
|
base_fee = parent_base_fee + base_fee_delta
|
||
|
|
else:
|
||
|
|
gas_used_delta = parent_gas_target - parent_gas_used
|
||
|
|
base_fee_delta = parent_base_fee * gas_used_delta / parent_gas_target / BASE_FEE_MAX_CHANGE_DENOMINATOR
|
||
|
|
base_fee = parent_base_fee - base_fee_delta
|
||
|
|
|
||
|
|
```
|