Only assign VMState._chaindb in __init__ + Mutable VMState

Author: hwwhww

evm/vm/base.py

@@ -96,26 +96,21 @@ def apply_transaction(self, transaction):
         Apply the transaction to the vm in the current block.
         """
         if self.is_stateless:
-            computation, block, trie_data = self.state.apply_transaction(
+            computation, block, trie_data = self.get_state_class().apply_transaction(
                 self.state,
                 transaction,
                 self.block,
                 is_stateless=True,
-                witness_db=self.chaindb,
             )
             self.block = block
 
-            # Update chaindb
             # TODO: Modify Chain.apply_transaction to update the local vm state before
-            # returning the computation object.
-            self.chaindb.db.wrapped_db.kv_store.update(
-                computation.vm_state.chaindb.db.wrapped_db.kv_store,
-            )
+
             # Persist changed transaction and receipt key-values to self.chaindb.
             for key, value in trie_data.items():
                 self.chaindb.db[key] = value
         else:
-            computation, _, _ = self.state.apply_transaction(
+            computation, _, _ = self.get_state_class().apply_transaction(
                 self.state,
                 transaction,
                 self.block,
@@ -270,7 +265,6 @@ def create_block(
                 transaction=transaction,
                 block=block,
                 is_stateless=True,
-                witness_db=witness_db,
             )
 
             if not computation.is_error:

evm/vm/forks/frontier/headers.py

@@ -90,7 +90,6 @@ def configure_frontier_header(vm, **header_params):
         setattr(vm.block.header, field_name, value)
 
     if 'timestamp' in header_params and vm.block.header.block_number > 0:
-        # TODO: replace vm.chaindb with vm.state.db?
         parent_header = vm.get_parent_header(vm.block.header, vm.chaindb)
         vm.block.header.difficulty = compute_frontier_difficulty(
             parent_header,

evm/vm_state.py

@@ -80,9 +80,9 @@ def gas_limit(self):
     #
     # chaindb
     #
-    @property
-    def chaindb(self):
-        return self._chaindb
+    # @property
+    # def chaindb(self):
+    #     return self._chaindb
 
     def set_chaindb(self, db):
         self._chaindb = db
@@ -205,37 +205,26 @@ def apply_transaction(
             vm_state,
             transaction,
             block,
-            is_stateless=True,
-            witness_db=None):
+            is_stateless=True):
         """
         Apply transaction to the given block
 
         :param vm_state: the VMState object
         :param transaction: the transaction need to be applied
         :param block: the block which the transaction applies on
         :param is_stateless: if is_stateless, call VMState.add_transactionto set block
-        :param witness_db: for stateless mode, use witness_db as chaindb
         :type vm_state: VMState
         :type transaction: Transaction
         :type block: Block
         :type is_stateless: bool
-        :type witness_db: BaseChainDB
 
         :return: the computation, applied block, and the trie_data
         :rtype: (Computation, Block, dict[bytes, bytes])
         """
         if is_stateless:
-            # Update block in this level.
-            assert witness_db is not None
-
-            # Don't change the given vm_state, block, and witness_db
-            vm_state = copy.deepcopy(vm_state)
+            # Don't modify the given block
             block = copy.deepcopy(block)
-            witness_db = copy.deepcopy(witness_db)
-
-            vm_state.set_chaindb(witness_db)
-            cls.block_header = block.header
-
+            vm_state.block_header = block.header
             computation, block_header = cls.execute_transaction(vm_state, transaction)
 
             # Set block.

tests/core/vm/test_vm_state.py

@@ -64,7 +64,6 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
 
     # Don't change these variables
     vm = chain.get_vm()
-    vm._is_stateless = False  # Only for testing
     chaindb = copy.deepcopy(vm.chaindb)
     block0 = copy.deepcopy(vm.block)
     prev_block_hash = chain.get_canonical_block_by_number(0).hash
@@ -74,6 +73,7 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
     # The first transaction
     chain1 = copy.deepcopy(chain)
     vm_example = chain1.get_vm()
+    vm_example._is_stateless = False  # Only for testing
     recipient1 = decode_hex('0x1111111111111111111111111111111111111111')
     amount = 100
     from_ = chain.funded_address
@@ -119,18 +119,16 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
         vm_state1,
         tx1,
         block1,
-        witness_db=chaindb1,
     )
     access_logs1 = computation.vm_state.access_logs
 
     # Check if prev_headers hasn't been changed
     assert parent_header.hash == prev_headers[0].hash
-
-    for key, value in enumerate(access_logs1.writes):
-        chaindb1.db[key] = value
+    # Make sure that block1 hasn't been changed
+    assert block1.header.state_root == initial_state_root
 
     vm_state1 = FrontierVMState(
-        chaindb=BaseChainDB(MemoryDB()),
+        chaindb=chaindb1,
         block_header=block.header,
         prev_headers=prev_headers,
         receipts=computation.vm_state.receipts,
@@ -139,7 +137,6 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
         vm_state1,
         tx2,
         block,
-        witness_db=computation.vm_state.chaindb,
     )
     access_logs2 = computation.vm_state.access_logs
     post_vm_state = computation.vm_state
@@ -158,12 +155,8 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
     assert block.header.transaction_root == result_block.header.transaction_root
     assert block.header.receipt_root == result_block.header.receipt_root
 
-    # Make sure that block1 hasn't been changed
-    assert block1.header.state_root == initial_state_root
-
     # Make sure that vm_state1 hasn't been changed
     assert post_vm_state.block_header.state_root == result_block.header.state_root
-    assert post_vm_state.block_header.state_root != vm_state1.block_header.state_root
 
     # (3) Testing using witness as db data
     # Witness_db
@@ -187,7 +180,6 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
         vm_state2,
         tx1,
         block2,
-        witness_db=witness_db,
     )
 
     # Update witness_db
@@ -196,7 +188,7 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
 
     # Apply the second transaction
     vm_state2 = FrontierVMState(
-        chaindb=BaseChainDB(MemoryDB()),
+        chaindb=witness_db,
         block_header=block.header,
         prev_headers=prev_headers,
         receipts=computation.vm_state.receipts,
@@ -205,7 +197,6 @@ def test_apply_transaction(chain_without_block_validation):  # noqa: F811
         vm_state2,
         tx2,
         block,
-        witness_db=witness_db,
     )
 
     # After applying