feat(forks): Add EIP-7623 logic to gas calculation

Author: marioevz

src/ethereum_test_forks/base_fork.py

@@ -44,7 +44,7 @@ class CalldataGasCalculator(Protocol):
     A protocol to calculate the transaction gas cost of calldata for a given fork.
     """
 
-    def __call__(self, *, data: BytesConvertible) -> int:
+    def __call__(self, *, data: BytesConvertible, floor: bool = False) -> int:
         """
         Returns the transaction gas cost of calldata given its contents.
         """
@@ -63,9 +63,20 @@ def __call__(
         contract_creation: bool = False,
         access_list: List[AccessList] | None = None,
         authorization_list_or_count: Sized | int | None = None,
+        return_cost_deducted_prior_execution: bool = False,
     ) -> int:
         """
         Returns the intrinsic gas cost of a transaction given its properties.
+
+        The `calldata` parameter is the data of the transaction.
+        The `contract_creation` parameter is whether the transaction creates a contract.
+        The `access_list` parameter is the list of access lists for the transaction.
+        The `authorization_list_or_count` parameter is the list of authorizations or the count of
+        authorizations for the transaction.
+        If `return_cost_deducted_prior_execution` parameter if set to False, the returned value
+        is equal to the minimum gas required for the transaction to be valid. If set to True, the
+        returned value is equal to the cost that is deducted from the gas limit before the
+        transaction starts execution.
         """
         pass
 

src/ethereum_test_forks/forks/forks.py

@@ -140,6 +140,8 @@ def gas_costs(cls, block_number: int = 0, timestamp: int = 0) -> GasCosts:
             G_MEMORY=3,
             G_TX_DATA_ZERO=4,
             G_TX_DATA_NON_ZERO=68,
+            G_TX_DATA_STANDARD_TOKEN_COST=0,
+            G_TX_DATA_FLOOR_TOKEN_COST=0,
             G_TRANSACTION=21_000,
             G_TRANSACTION_CREATE=32_000,
             G_LOG=375,
@@ -184,7 +186,7 @@ def calldata_gas_calculator(
         """
         gas_costs = cls.gas_costs(block_number, timestamp)
 
-        def fn(*, data: BytesConvertible) -> int:
+        def fn(*, data: BytesConvertible, floor: bool = False) -> int:
             cost = 0
             for b in Bytes(data):
                 if b == 0:
@@ -211,6 +213,7 @@ def fn(
             contract_creation: bool = False,
             access_list: List[AccessList] | None = None,
             authorization_list_or_count: Sized | int | None = None,
+            return_cost_deducted_prior_execution: bool = False,
         ) -> int:
             assert access_list is None, f"Access list is not supported in {cls.name()}"
             assert (
@@ -633,6 +636,7 @@ def fn(
             contract_creation: bool = False,
             access_list: List[AccessList] | None = None,
             authorization_list_or_count: Sized | int | None = None,
+            return_cost_deducted_prior_execution: bool = False,
         ) -> int:
             intrinsic_cost: int = super_fn(
                 calldata=calldata,
@@ -764,7 +768,7 @@ def valid_opcodes(
     @classmethod
     def gas_costs(cls, block_number: int = 0, timestamp: int = 0) -> GasCosts:
         """
-        Returns a dataclass with the defined gas costs constants for genesis.
+        On Istanbul, the non-zero transaction data byte cost is reduced to 16 due to EIP-2028.
         """
         return replace(
             super(Istanbul, cls).gas_costs(block_number, timestamp),
@@ -818,6 +822,7 @@ def fn(
             contract_creation: bool = False,
             access_list: List[AccessList] | None = None,
             authorization_list_or_count: Sized | int | None = None,
+            return_cost_deducted_prior_execution: bool = False,
         ) -> int:
             intrinsic_cost: int = super_fn(
                 calldata=calldata,
@@ -1127,6 +1132,17 @@ def precompiles(cls, block_number: int = 0, timestamp: int = 0) -> List[Address]
             block_number, timestamp
         )
 
+    @classmethod
+    def gas_costs(cls, block_number: int = 0, timestamp: int = 0) -> GasCosts:
+        """
+        On Prague, the standard token cost and the floor token costs are introduced due to EIP-7623
+        """
+        return replace(
+            super(Prague, cls).gas_costs(block_number, timestamp),
+            G_TX_DATA_STANDARD_TOKEN_COST=4,  # https://eips.ethereum.org/EIPS/eip-7623
+            G_TX_DATA_FLOOR_TOKEN_COST=10,
+        )
+
     @classmethod
     def system_contracts(cls, block_number: int = 0, timestamp: int = 0) -> List[Address]:
         """
@@ -1146,6 +1162,29 @@ def max_request_type(cls, block_number: int = 0, timestamp: int = 0) -> int:
         """
         return 2
 
+    @classmethod
+    def calldata_gas_calculator(
+        cls, block_number: int = 0, timestamp: int = 0
+    ) -> CalldataGasCalculator:
+        """
+        Returns a callable that calculates the transaction gas cost for its calldata
+        depending on its contents.
+        """
+        gas_costs = cls.gas_costs(block_number, timestamp)
+
+        def fn(*, data: BytesConvertible, floor: bool = False) -> int:
+            tokens = 0
+            for b in Bytes(data):
+                if b == 0:
+                    tokens += 1
+                else:
+                    tokens += 4
+            if floor:
+                return tokens * gas_costs.G_TX_DATA_FLOOR_TOKEN_COST
+            return tokens * gas_costs.G_TX_DATA_STANDARD_TOKEN_COST
+
+        return fn
+
     @classmethod
     def transaction_intrinsic_cost_calculator(
         cls, block_number: int = 0, timestamp: int = 0
@@ -1164,17 +1203,24 @@ def fn(
             contract_creation: bool = False,
             access_list: List[AccessList] | None = None,
             authorization_list_or_count: Sized | int | None = None,
+            return_cost_deducted_prior_execution: bool = False,
         ) -> int:
             intrinsic_cost: int = super_fn(
                 calldata=calldata,
                 contract_creation=contract_creation,
                 access_list=access_list,
+                return_cost_deducted_prior_execution=False,
             )
             if authorization_list_or_count is not None:
                 if isinstance(authorization_list_or_count, Sized):
                     authorization_list_or_count = len(authorization_list_or_count)
                 intrinsic_cost += authorization_list_or_count * gas_costs.G_AUTHORIZATION
-            return intrinsic_cost
+
+            if return_cost_deducted_prior_execution:
+                return intrinsic_cost
+
+            floor_data_cost = cls.calldata_gas_calculator()(data=calldata, floor=True)
+            return max(intrinsic_cost, floor_data_cost + gas_costs.G_TRANSACTION)
 
         return fn
 

src/ethereum_test_forks/gas_costs.py

@@ -45,6 +45,8 @@ class GasCosts:
 
     G_TX_DATA_ZERO: int
     G_TX_DATA_NON_ZERO: int
+    G_TX_DATA_STANDARD_TOKEN_COST: int
+    G_TX_DATA_FLOOR_TOKEN_COST: int
 
     G_TRANSACTION: int
     G_TRANSACTION_CREATE: int