add transient storage

eth/abc.py

@@ -2446,6 +2446,22 @@ class AccountAPI(ABC):
     code_hash: Hash32
 
 
+class TransientStorageAPI(ABC):
+    @abstractmethod
+    def get_transient_storage(self, address: Address, slot: int) -> int:
+        """
+        Return the transient storage for ``address`` at slot ``slot``.
+        """
+        ...
+
+    @abstractmethod
+    def set_transient_storage(self, address: Address, slot: int, value: int) -> None:
+        """
+        Return the transient storage for ``address`` at slot ``slot``.
+        """
+        ...
+
+
 class AccountDatabaseAPI(ABC):
     """
     A class representing a database for accounts.
@@ -3114,6 +3130,23 @@ def mark_address_warm(self, address: Address) -> None:
         """
         ...
 
+    #
+    # transient storage
+    #
+    @abstractmethod
+    def get_transient_storage(self, address: Address, slot: int) -> int:
+        """
+        Return the transient storage for ``address`` at slot ``slot``.
+        """
+        ...
+
+    @abstractmethod
+    def set_transient_storage(self, address: Address, slot: int, value: int) -> None:
+        """
+        Return the transient storage for ``address`` at slot ``slot``.
+        """
+        ...
+
     #
     # Access self._chaindb
     #

eth/vm/forks/cancun/state.py

@@ -2,13 +2,21 @@
     Type,
 )
 
+from eth_typing import (
+    Address,
+)
+
 from eth.abc import (
     TransactionExecutorAPI,
+    TransientStorageAPI,
 )
-
-from ..shanghai import (
+from eth.vm.forks.shanghai import (
     ShanghaiState,
 )
+from eth.vm.transient_mapping import (
+    TransientStorage,
+)
+
 from ..shanghai.state import (
     ShanghaiTransactionExecutor,
 )
@@ -18,9 +26,43 @@
 
 
 class CancunTransactionExecutor(ShanghaiTransactionExecutor):
-    pass
+    def build_computation(self, *args, **kwargs):
+        self.vm_state.reset_transient_storage()
+        return super().build_computation(*args, **kwargs)
 
 
 class CancunState(ShanghaiState):
     computation_class = CancunComputation
     transaction_executor_class: Type[TransactionExecutorAPI] = CancunTransactionExecutor
+
+    _transient_storage_class: Type[TransientStorageAPI] = TransientStorage
+    _transient_storage: TransientStorageAPI = None
+
+    @property
+    def transient_storage(self):
+        if self._transient_storage is None:
+            self.reset_transient_storage()
+
+        return self._transient_storage
+
+    def reset_transient_storage(self):
+        self._transient_storage = self._transient_storage_class()
+
+    def get_transient_storage(self, address: Address, slot: int) -> int:
+        return self.transient_storage.get_transient_storage(address, slot)
+
+    def set_transient_storage(self, address: Address, slot: int, value: int) -> None:
+        return self.transient_storage.set_transient_storage(address, slot, value)
+
+    def snapshot(self):
+        state_root, checkpoint = super().snapshot()
+        self.transient_storage.record(checkpoint)
+        return state_root, checkpoint
+
+    def commit(self, snapshot):
+        super().commit(snapshot)
+        self.transient_storage.commit(snapshot)
+
+    def discard(self, snapshot):
+        super().discard(snapshot)
+        self.transient_storage.discard(snapshot)

eth/vm/logic/transient.py

@@ -0,0 +1,14 @@
+def tstore(computation):
+    address = computation.msg.storage_address
+    slot, value = computation.stack_pop_ints(2)
+
+    computation.state.set_transient_storage(address, slot, value)
+
+
+def tload(computation):
+    address = computation.msg.storage_address
+    slot = computation.stack_pop1_int()
+    state = computation.state
+    value = state.get_transient_storage(address, slot)
+
+    computation.push_int(value)

eth/vm/state.py

@@ -203,6 +203,12 @@ def is_address_warm(self, address: Address) -> bool:
     def mark_address_warm(self, address: Address) -> None:
         self._account_db.mark_address_warm(address)
 
+    def get_transient_storage(self, address: Address, slot: int) -> int:
+        raise AttributeError("No transient_storage has been set for this State")
+
+    def set_transient_storage(self, address: Address, slot: int, value: int) -> None:
+        raise AttributeError("No transient_storage has been set for this State")
+
     #
     # Access self._chaindb
     #

eth/vm/transient_mapping.py

@@ -0,0 +1,53 @@
+from eth_utils import (
+    int_to_big_endian,
+)
+
+from eth.abc import (
+    TransientStorageAPI,
+)
+from eth.db.backends.memory import (
+    MemoryDB,
+)
+from eth.db.journal import (
+    JournalDB,
+)
+from eth.typing import (
+    Address,
+)
+from eth.validation import (
+    validate_canonical_address,
+    validate_uint256,
+)
+
+
+class TransientStorage(TransientStorageAPI):
+    def __init__(self):
+        self._transient_storage = JournalDB(MemoryDB())
+
+    @staticmethod
+    def _get_key(address: Address, slot: int) -> bytes:
+        return address + int_to_big_endian(slot)
+
+    def get_transient_storage(self, address: Address, slot: int) -> int:
+        validate_canonical_address(address)
+        validate_uint256(slot)
+
+        key = self._get_key(address, slot)
+        return self._transient_storage.get(key, 0)
+
+    def set_transient_storage(self, address: Address, slot: int, value: int) -> None:
+        validate_canonical_address(address)
+        validate_uint256(slot)
+        validate_uint256(value)
+
+        key = self._get_key(address, slot)
+        self._transient_storage[key] = value
+
+    def record(self, checkpoint):
+        self._transient_storage.record(checkpoint)
+
+    def commit(self, checkpoint):
+        self._transient_storage.commit(checkpoint)
+
+    def discard(self, checkpoint):
+        self._transient_storage.discard(checkpoint)