Merge pull request #238 from NIC619/account_abstraction_ENTRY_POINT

Sharding[VM,Block,Transaction,Message] and sharding transaction/message execution logic

evm/constants.py

@@ -171,3 +171,9 @@
 BALANCE_TRIE_PREFIX = b'\x01'
 CODE_TRIE_PREFIX = b'\x02'
 STORAGE_TRIE_PREFIX = b'\x03'
+
+
+#
+# Account Abstraction
+#
+ENTRY_POINT = 20 * b'\xff'

evm/rlp/transactions.py

@@ -46,11 +46,11 @@ def sender(self):
         return self.get_sender()
 
     @property
-    def intrensic_gas(self):
+    def intrinsic_gas(self):
         """
-        Convenience property for the return value of `get_intrensic_gas`
+        Convenience property for the return value of `get_intrinsic_gas`
         """
-        return self.get_intrensic_gas()
+        return self.get_intrinsic_gas()
 
     # +-------------------------------------------------------------+
     # | API that must be implemented by all Transaction subclasses. |
@@ -64,7 +64,7 @@ def validate(self):
         Hook called during instantiation to ensure that all transaction
         parameters pass validation rules.
         """
-        if self.intrensic_gas > self.gas:
+        if self.intrinsic_gas > self.gas:
             raise ValidationError("Insufficient gas")
         self.check_signature_validity()
 
@@ -96,7 +96,7 @@ def get_sender(self):
     #
     # Base gas costs
     #
-    def get_intrensic_gas(self):
+    def get_intrinsic_gas(self):
         """
         Compute the baseline gas cost for this transaction.  This is the amount
         of gas needed to send this transaction (but that is not actually used
@@ -153,9 +153,9 @@ class BaseShardingTransaction(rlp.Serializable):
     fields = [
         ('chain_id', big_endian_int),
         ('shard_id', big_endian_int),
-        ('target', address),
+        ('to', address),
         ('data', binary),
-        ('start_gas', big_endian_int),
+        ('gas', big_endian_int),
         ('gas_price', big_endian_int),
         ('access_list', access_list_sedes),
         ('code', binary),
@@ -164,3 +164,32 @@ class BaseShardingTransaction(rlp.Serializable):
     @property
     def hash(self):
         return keccak(rlp.encode(self))
+
+    #
+    # Validation
+    #
+    def validate(self):
+        """
+        Hook called during instantiation to ensure that all transaction
+        parameters pass validation rules.
+        """
+        if self.intrinsic_gas > self.gas:
+            raise ValidationError("Insufficient gas")
+
+    @property
+    def intrinsic_gas(self):
+        """
+        Convenience property for the return value of `get_intrinsic_gas`
+        """
+        return self.get_intrinsic_gas()
+
+    #
+    # Base gas costs
+    #
+    def get_intrinsic_gas(self):
+        """
+        Compute the baseline gas cost for this transaction.  This is the amount
+        of gas needed to send this transaction (but that is not actually used
+        for computation).
+        """
+        raise NotImplementedError("Must be implemented by subclasses")

evm/utils/address.py

@@ -1,5 +1,9 @@
 import rlp
 
+from evm.validation import (
+    validate_is_bytes,
+    validate_length_lte,
+)
 from .keccak import (
     keccak,
 )
@@ -16,3 +20,15 @@ def force_bytes_to_address(value):
 
 def generate_contract_address(address, nonce):
     return keccak(rlp.encode([address, nonce]))[-20:]
+
+
+def generate_create2_contract_address(salt, code):
+    """
+    If contract is created by transaction, `salt` should be empty.
+    If contract is created by contract, `salt` is set by the creator contract.
+    """
+    validate_length_lte(salt, 32, title="Salt")
+    validate_is_bytes(salt)
+    validate_is_bytes(code)
+
+    return keccak(pad_left(salt, 32, b'\x00') + code)[-20:]

evm/vm/forks/__init__.py

@@ -13,3 +13,6 @@
 from .byzantium import (  # noqa: F401
     ByzantiumVM,
 )
+from .sharding import (  # noqa: F401
+    ShardingVM,
+)

evm/vm/forks/frontier/__init__.py

@@ -64,7 +64,7 @@ def _execute_frontier_transaction(vm, transaction):
         state_db.increment_nonce(transaction.sender)
 
         # Setup VM Message
-        message_gas = transaction.gas - transaction.intrensic_gas
+        message_gas = transaction.gas - transaction.intrinsic_gas
 
         if transaction.to == constants.CREATE_CONTRACT_ADDRESS:
             contract_address = generate_contract_address(

evm/vm/forks/frontier/transactions.py

@@ -59,8 +59,8 @@ def check_signature_validity(self):
     def get_sender(self):
         return extract_transaction_sender(self)
 
-    def get_intrensic_gas(self):
-        return _get_frontier_intrensic_gas(self.data)
+    def get_intrinsic_gas(self):
+        return _get_frontier_intrinsic_gas(self.data)
 
     def get_message_for_signing(self):
         return rlp.encode(FrontierUnsignedTransaction(
@@ -104,7 +104,7 @@ def as_signed_transaction(self, private_key):
         )
 
 
-def _get_frontier_intrensic_gas(transaction_data):
+def _get_frontier_intrinsic_gas(transaction_data):
     num_zero_bytes = transaction_data.count(b'\x00')
     num_non_zero_bytes = len(transaction_data) - num_zero_bytes
     return (

evm/vm/forks/homestead/transactions.py

@@ -26,8 +26,8 @@ def validate(self):
         super(HomesteadTransaction, self).validate()
         validate_lt_secpk1n2(self.s, title="Transaction.s")
 
-    def get_intrensic_gas(self):
-        return _get_homestead_intrensic_gas(self)
+    def get_intrinsic_gas(self):
+        return _get_homestead_intrinsic_gas(self)
 
     def get_message_for_signing(self):
         return rlp.encode(HomesteadUnsignedTransaction(
@@ -60,7 +60,7 @@ def as_signed_transaction(self, private_key):
         )
 
 
-def _get_homestead_intrensic_gas(transaction):
+def _get_homestead_intrinsic_gas(transaction):
     num_zero_bytes = transaction.data.count(b'\x00')
     num_non_zero_bytes = len(transaction.data) - num_zero_bytes
     if transaction.to == CREATE_CONTRACT_ADDRESS:

evm/vm/forks/sharding/__init__.py

@@ -0,0 +1,173 @@
+from evm.constants import (
+    ENTRY_POINT,
+)
+
+from evm.exceptions import (
+    ContractCreationCollision,
+)
+
+from evm.vm.message import (
+    ShardingMessage,
+)
+from evm.vm.vm_state import (
+    VMState,
+)
+
+from evm.utils.address import (
+    generate_create2_contract_address,
+)
+from evm.utils.hexadecimal import (
+    encode_hex,
+)
+from evm.utils.keccak import (
+    keccak,
+)
+
+from ..byzantium import ByzantiumVM
+from ..frontier.constants import (
+    REFUND_SELFDESTRUCT,
+)
+from .computation import ShardingComputation
+from .validation import validate_sharding_transaction
+from .blocks import ShardingBlock
+
+
+def _execute_sharding_transaction(vm, transaction):
+    #
+    # 1) Pre Computation
+    #
+
+    # Validate the transaction
+    transaction.validate()
+
+    vm.validate_transaction(transaction)
+
+    gas_fee = transaction.gas * transaction.gas_price
+    with vm.state.state_db() as state_db:
+        # Buy Gas
+        state_db.delta_balance(transaction.to, -1 * gas_fee)
+
+        # Setup VM Message
+        message_gas = transaction.gas - transaction.intrinsic_gas
+
+        if transaction.code:
+            contract_address = generate_create2_contract_address(
+                b'',
+                transaction.code,
+            )
+            data = b''
+            code = transaction.code
+            is_create = True
+        else:
+            contract_address = None
+            data = transaction.data
+            code = state_db.get_code(transaction.to)
+            is_create = False
+
+    vm.logger.info(
+        (
+            "TRANSACTION: to: %s | gas: %s | "
+            "gas-price: %s | data-hash: %s | code-hash: %s"
+        ),
+        encode_hex(transaction.to),
+        transaction.gas,
+        transaction.gas_price,
+        encode_hex(keccak(transaction.data)),
+        encode_hex(keccak(transaction.code)),
+    )
+
+    message = ShardingMessage(
+        gas=message_gas,
+        gas_price=transaction.gas_price,
+        to=transaction.to,
+        sender=ENTRY_POINT,
+        value=0,
+        data=data,
+        code=code,
+        is_create=is_create,
+    )
+
+    #
+    # 2) Apply the message to the VM.
+    #
+    if message.is_create:
+        with vm.state.state_db(read_only=True) as state_db:
+            is_collision = state_db.account_has_code_or_nonce(contract_address)
+
+        if is_collision:
+            # The address of the newly created contract has collided
+            # with an existing contract address.
+            computation = vm.get_computation(message)
+            computation._error = ContractCreationCollision(
+                "Address collision while creating contract: {0}".format(
+                    encode_hex(contract_address),
+                )
+            )
+            vm.logger.debug(
+                "Address collision while creating contract: %s",
+                encode_hex(contract_address),
+            )
+        else:
+            computation = vm.get_computation(message).apply_create_message()
+    else:
+        computation = vm.get_computation(message).apply_message()
+
+    #
+    # 2) Post Computation
+    #
+    # Self Destruct Refunds
+    num_deletions = len(computation.get_accounts_for_deletion())
+    if num_deletions:
+        computation.gas_meter.refund_gas(REFUND_SELFDESTRUCT * num_deletions)
+
+    # Gas Refunds
+    gas_remaining = computation.get_gas_remaining()
+    gas_refunded = computation.get_gas_refund()
+    gas_used = transaction.gas - gas_remaining
+    gas_refund = min(gas_refunded, gas_used // 2)
+    gas_refund_amount = (gas_refund + gas_remaining) * transaction.gas_price
+
+    if gas_refund_amount:
+        vm.logger.debug(
+            'TRANSACTION REFUND: %s -> %s',
+            gas_refund_amount,
+            encode_hex(message.to),
+        )
+
+        with vm.state.state_db() as state_db:
+            state_db.delta_balance(message.to, gas_refund_amount)
+
+    # Miner Fees
+    transaction_fee = (transaction.gas - gas_remaining - gas_refund) * transaction.gas_price
+    vm.logger.debug(
+        'TRANSACTION FEE: %s -> %s',
+        transaction_fee,
+        encode_hex(vm.block.header.coinbase),
+    )
+    with vm.state.state_db() as state_db:
+        state_db.delta_balance(vm.block.header.coinbase, transaction_fee)
+
+    # Process Self Destructs
+    with vm.state.state_db() as state_db:
+        for account, beneficiary in computation.get_accounts_for_deletion():
+            # TODO: need to figure out how we prevent multiple selfdestructs from
+            # the same account and if this is the right place to put this.
+            vm.logger.debug('DELETING ACCOUNT: %s', encode_hex(account))
+
+            # TODO: this balance setting is likely superflous and can be
+            # removed since `delete_account` does this.
+            state_db.set_balance(account, 0)
+            state_db.delete_account(account)
+
+    return computation
+
+
+ShardingVM = ByzantiumVM.configure(
+    name='ShardingVM',
+    _computation_class=ShardingComputation,
+    _block_class=ShardingBlock,
+    _state_class=VMState,
+    # Method overrides
+    validate_transaction=validate_sharding_transaction,
+    execute_transaction=_execute_sharding_transaction,
+)

evm/vm/forks/sharding/blocks.py

@@ -0,0 +1,21 @@
+from rlp.sedes import (
+    CountableList,
+)
+from evm.rlp.headers import (
+    BlockHeader,
+)
+from evm.vm.forks.homestead.blocks import (
+    HomesteadBlock,
+)
+from .transactions import (
+    ShardingTransaction,
+)
+
+
+class ShardingBlock(HomesteadBlock):
+    transaction_class = ShardingTransaction
+    fields = [
+        ('header', BlockHeader),
+        ('transactions', CountableList(transaction_class)),
+        ('uncles', CountableList(BlockHeader))
+    ]