mirror of https://github.com/status-im/nim-eth.git
48 lines
1.5 KiB
Nim
48 lines
1.5 KiB
Nim
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import
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common/eth_types
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const
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EIP1559_BASE_FEE_CHANGE_DENOMINATOR* = ##\
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## Bounds the amount the base fee can change between blocks.
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8
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EIP1559_ELASTICITY_MULTIPLIER* = ##\
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## Bounds the maximum gas limit an EIP-1559 block may have.
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2
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EIP1559_INITIAL_BASE_FEE* = ##\
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## Initial base fee for Eip1559 blocks.
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1000000000.u256
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proc calcEip1599BaseFee*(parentGasLimit, parentGasUsed: GasInt;
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parentBaseFee: UInt256): UInt256 =
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## calculates the basefee of the header.
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let parentGasTarget = parentGasLimit div EIP1559_ELASTICITY_MULTIPLIER
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# If the parent gasUsed is the same as the target, the baseFee remains
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# unchanged.
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if parentGasUsed == parentGasTarget:
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return parentBaseFee
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let parentGasDenom = parentGasTarget.u256 *
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EIP1559_BASE_FEE_CHANGE_DENOMINATOR.u256
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if parentGasTarget < parentGasUsed:
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# If the parent block used more gas than its target, the baseFee should
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# increase.
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let
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gasUsedDelta = (parentGasUsed - parentGasTarget).u256
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baseFeeDelta = (parentBaseFee * gasUsedDelta) div parentGasDenom
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return parentBaseFee + max(baseFeeDelta, 1.u256)
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else:
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# Otherwise if the parent block used less gas than its target, the
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# baseFee should decrease.
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let
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gasUsedDelta = (parentGasTarget - parentGasUsed).u256
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baseFeeDelta = (parentBaseFee * gasUsedDelta) div parentGasDenom
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return max(parentBaseFee - baseFeeDelta, 0.u256)
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