Beispiel #1
0
class StorageLookup(BaseDB):
    """
    This lookup converts lookups of storage slot integers into the appropriate trie lookup.
    Similarly, it persists changes to the appropriate trie at write time.

    StorageLookup also tracks the state roots changed since the last persist.
    """
    logger = get_extended_debug_logger("eth.db.storage.StorageLookup")

    # The trie that is modified in-place, used to calculate storage root on-demand
    _write_trie: HexaryTrie

    # These are the new trie nodes, waiting to be committed to disk
    _trie_nodes_batch: BatchDB

    # When deleting an account, push the pending write info onto this stack.
    # This stack can get as big as the number of transactions per block: one for each delete.
    _historical_write_tries: List[PendingWrites]

    def __init__(self, db: DatabaseAPI, storage_root: Hash32,
                 address: Address) -> None:
        self._db = db

        # Set the starting root hash, to be used for on-disk storage read lookups
        self._initialize_to_root_hash(storage_root)

        self._address = address

    def _get_write_trie(self) -> HexaryTrie:
        if self._trie_nodes_batch is None:
            self._trie_nodes_batch = BatchDB(self._db,
                                             read_through_deletes=True)

        if self._write_trie is None:
            batch_db = self._trie_nodes_batch
            self._write_trie = HexaryTrie(batch_db,
                                          root_hash=self._starting_root_hash,
                                          prune=True)

        return self._write_trie

    def _get_read_trie(self) -> HexaryTrie:
        if self._write_trie is not None:
            return self._write_trie
        else:
            # Creating "HexaryTrie" is a pretty light operation, so not a huge cost
            # to create a new one at every read, but we could
            # cache the read trie, if this becomes a bottleneck.
            return HexaryTrie(self._db, root_hash=self._starting_root_hash)

    def _decode_key(self, key: bytes) -> bytes:
        padded_slot = pad32(key)
        return keccak(padded_slot)

    def __getitem__(self, key: bytes) -> bytes:
        hashed_slot = self._decode_key(key)
        read_trie = self._get_read_trie()
        try:
            return read_trie[hashed_slot]
        except trie_exceptions.MissingTrieNode as exc:
            raise MissingStorageTrieNode(
                exc.missing_node_hash,
                self._starting_root_hash,
                exc.requested_key,
                self._address,
            ) from exc

    def __setitem__(self, key: bytes, value: bytes) -> None:
        hashed_slot = self._decode_key(key)
        write_trie = self._get_write_trie()
        write_trie[hashed_slot] = value

    def _exists(self, key: bytes) -> bool:
        # used by BaseDB for __contains__ checks
        hashed_slot = self._decode_key(key)
        read_trie = self._get_read_trie()
        return hashed_slot in read_trie

    def __delitem__(self, key: bytes) -> None:
        hashed_slot = self._decode_key(key)
        write_trie = self._get_write_trie()
        try:
            del write_trie[hashed_slot]
        except trie_exceptions.MissingTrieNode as exc:
            raise MissingStorageTrieNode(
                exc.missing_node_hash,
                self._starting_root_hash,
                exc.requested_key,
                self._address,
            ) from exc

    @property
    def has_changed_root(self) -> bool:
        return self._write_trie is not None

    def get_changed_root(self) -> Hash32:
        if self._write_trie is not None:
            return self._write_trie.root_hash
        else:
            raise ValidationError(
                "Asked for changed root when no writes have been made")

    def _initialize_to_root_hash(self, root_hash: Hash32) -> None:
        self._starting_root_hash = root_hash
        self._write_trie = None
        self._trie_nodes_batch = None

        # Reset the historical writes, which can't be reverted after committing
        self._historical_write_tries = []

    def commit_to(self, db: DatabaseAPI) -> None:
        """
        Trying to commit changes when nothing has been written will raise a
        ValidationError
        """
        self.logger.debug2('persist storage root to data store')
        if self._trie_nodes_batch is None:
            raise ValidationError(
                "It is invalid to commit an account's storage if it has no pending changes. "
                "Always check storage_lookup.has_changed_root before attempting to commit. "
                f"Write tries on stack = {len(self._historical_write_tries)}; Root hash = "
                f"{encode_hex(self._starting_root_hash)}")
        self._trie_nodes_batch.commit_to(db, apply_deletes=False)

        # Mark the trie as having been all written out to the database.
        # It removes the 'dirty' flag and clears out any pending writes.
        self._initialize_to_root_hash(self._write_trie.root_hash)

    def new_trie(self) -> int:
        """
        Switch to an empty trie. Save the old trie, and pending writes, in
        case of a revert.

        :return: index for reviving the previous trie
        """
        write_trie = self._get_write_trie()

        # Write the previous trie into a historical stack
        self._historical_write_tries.append(
            PendingWrites(
                write_trie,
                self._trie_nodes_batch,
                self._starting_root_hash,
            ))

        new_idx = len(self._historical_write_tries)
        self._starting_root_hash = BLANK_ROOT_HASH
        self._write_trie = None
        self._trie_nodes_batch = None

        return new_idx

    def rollback_trie(self, trie_index: int) -> None:
        """
        Revert back to the previous trie, using the index returned by a
        :meth:`~new_trie` call. The index returned by that call returns you
        to the trie in place *before* the call.

        :param trie_index: index for reviving the previous trie
        """

        if trie_index >= len(self._historical_write_tries):
            raise ValidationError(
                f"Trying to roll back a delete to index {trie_index}, but there are only"
                f" {len(self._historical_write_tries)} indices available.")

        (
            self._write_trie,
            self._trie_nodes_batch,
            self._starting_root_hash,
        ) = self._historical_write_tries[trie_index]

        # Cannot roll forward after a rollback, so remove created/ignored tries.
        # This also deletes the trie that you just reverted to. It will be re-added
        # to the stack when the next new_trie() is called.
        del self._historical_write_tries[trie_index:]
Beispiel #2
0
class AccountDB(BaseAccountDB):

    logger = cast(ExtendedDebugLogger,
                  logging.getLogger('eth.db.account.AccountDB'))

    def __init__(self,
                 db: BaseAtomicDB,
                 state_root: Hash32 = BLANK_ROOT_HASH) -> None:
        r"""
        Internal implementation details (subject to rapid change):
        Database entries go through several pipes, like so...

        .. code::

            db > _batchdb ---------------------------> _journaldb ----------------> code lookups
             \
              -> _batchtrie -> _trie -> _trie_cache -> _journaltrie --------------> account lookups

        Journaling sequesters writes at the _journal* attrs ^, until persist is called.

        _batchtrie enables us to prune all trie changes while building
        state,  without deleting old trie roots.

        _batchdb and _batchtrie together enable us to make the state root,
        without saving everything to the database.

        _journaldb is a journaling of the keys and values used to store
        code and account storage.

        _trie is a hash-trie, used to generate the state root

        _trie_cache is a cache tied to the state root of the trie. It
        is important that this cache is checked *after* looking for
        the key in _journaltrie, because the cache is only invalidated
        after a state root change.

        _journaltrie is a journaling of the accounts (an address->rlp mapping,
        rather than the nodes stored by the trie). This enables
        a squashing of all account changes before pushing them into the trie.

        .. NOTE:: StorageDB works similarly

        AccountDB synchronizes the snapshot/revert/persist of both of the
        journals.
        """
        self._raw_store_db = db
        self._batchdb = BatchDB(db)
        self._batchtrie = BatchDB(db, read_through_deletes=True)
        self._journaldb = JournalDB(self._batchdb)
        self._trie = HashTrie(
            HexaryTrie(self._batchtrie, state_root, prune=True))
        self._trie_cache = CacheDB(self._trie)
        self._journaltrie = JournalDB(self._trie_cache)
        self._account_cache = LRU(2048)
        self._account_stores = {}  # type: Dict[Address, AccountStorageDB]
        self._dirty_accounts = set()  # type: Set[Address]
        self._root_hash_at_last_persist = state_root

    @property
    def state_root(self) -> Hash32:
        return self._trie.root_hash

    @state_root.setter
    def state_root(self, value: Hash32) -> None:
        if self._trie.root_hash != value:
            self._trie_cache.reset_cache()
            self._trie.root_hash = value

    def has_root(self, state_root: bytes) -> bool:
        return state_root in self._batchtrie

    #
    # Storage
    #
    def get_storage(self,
                    address: Address,
                    slot: int,
                    from_journal: bool = True) -> int:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(slot, title="Storage Slot")

        account_store = self._get_address_store(address)
        return account_store.get(slot, from_journal)

    def set_storage(self, address: Address, slot: int, value: int) -> None:
        validate_uint256(value, title="Storage Value")
        validate_uint256(slot, title="Storage Slot")
        validate_canonical_address(address, title="Storage Address")

        account_store = self._get_address_store(address)
        self._dirty_accounts.add(address)
        account_store.set(slot, value)

    def delete_storage(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        self._set_storage_root(address, BLANK_ROOT_HASH)
        self._wipe_storage(address)

    def _wipe_storage(self, address: Address) -> None:
        """
        Wipe out the storage, without explicitly handling the storage root update
        """
        account_store = self._get_address_store(address)
        self._dirty_accounts.add(address)
        account_store.delete()

    def _get_address_store(self, address: Address) -> AccountStorageDB:
        if address in self._account_stores:
            store = self._account_stores[address]
        else:
            storage_root = self._get_storage_root(address)
            store = AccountStorageDB(self._raw_store_db, storage_root, address)
            self._account_stores[address] = store
        return store

    def _dirty_account_stores(
            self) -> Iterable[Tuple[Address, AccountStorageDB]]:
        for address in self._dirty_accounts:
            store = self._account_stores[address]
            yield address, store

    @to_tuple
    def _get_changed_roots(self) -> Iterable[Tuple[Address, Hash32]]:
        # list all the accounts that were changed, and their new storage roots
        for address, store in self._dirty_account_stores():
            if store.has_changed_root:
                yield address, store.get_changed_root()

    def _get_storage_root(self, address: Address) -> Hash32:
        account = self._get_account(address)
        return account.storage_root

    def _set_storage_root(self, address: Address,
                          new_storage_root: Hash32) -> None:
        account = self._get_account(address)
        self._set_account(address, account.copy(storage_root=new_storage_root))

    def _validate_flushed_storage(self, address: Address,
                                  store: AccountStorageDB) -> None:
        if store.has_changed_root:
            actual_storage_root = self._get_storage_root(address)
            expected_storage_root = store.get_changed_root()
            if expected_storage_root != actual_storage_root:
                raise ValidationError(
                    "Storage root was not saved to account before trying to persist roots. "
                    "Account %r had storage %r, but should be %r." % (
                        address,
                        actual_storage_root,
                        expected_storage_root,
                    ))

    #
    # Balance
    #
    def get_balance(self, address: Address) -> int:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.balance

    def set_balance(self, address: Address, balance: int) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(balance, title="Account Balance")

        account = self._get_account(address)
        self._set_account(address, account.copy(balance=balance))

    #
    # Nonce
    #
    def get_nonce(self, address: Address) -> int:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.nonce

    def set_nonce(self, address: Address, nonce: int) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(nonce, title="Nonce")

        account = self._get_account(address)
        self._set_account(address, account.copy(nonce=nonce))

    def increment_nonce(self, address: Address) -> None:
        current_nonce = self.get_nonce(address)
        self.set_nonce(address, current_nonce + 1)

    #
    # Code
    #
    def get_code(self, address: Address) -> bytes:
        validate_canonical_address(address, title="Storage Address")

        code_hash = self.get_code_hash(address)
        if code_hash == EMPTY_SHA3:
            return b''
        else:
            try:
                return self._journaldb[code_hash]
            except KeyError:
                raise MissingBytecode(code_hash) from KeyError

    def set_code(self, address: Address, code: bytes) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_is_bytes(code, title="Code")

        account = self._get_account(address)

        code_hash = keccak(code)
        self._journaldb[code_hash] = code
        self._set_account(address, account.copy(code_hash=code_hash))

    def get_code_hash(self, address: Address) -> Hash32:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.code_hash

    def delete_code(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        self._set_account(address, account.copy(code_hash=EMPTY_SHA3))

    #
    # Account Methods
    #
    def account_has_code_or_nonce(self, address: Address) -> bool:
        return self.get_nonce(address) != 0 or self.get_code_hash(
            address) != EMPTY_SHA3

    def delete_account(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        if address in self._account_cache:
            del self._account_cache[address]
        del self._journaltrie[address]

        self._wipe_storage(address)

    def account_exists(self, address: Address) -> bool:
        validate_canonical_address(address, title="Storage Address")
        account_rlp = self._get_encoded_account(address, from_journal=True)
        return account_rlp != b''

    def touch_account(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        self._set_account(address, account)

    def account_is_empty(self, address: Address) -> bool:
        return not self.account_has_code_or_nonce(
            address) and self.get_balance(address) == 0

    #
    # Internal
    #
    def _get_encoded_account(self,
                             address: Address,
                             from_journal: bool = True) -> bytes:
        lookup_trie = self._journaltrie if from_journal else self._trie_cache

        try:
            return lookup_trie[address]
        except trie_exceptions.MissingTrieNode as exc:
            raise MissingAccountTrieNode(*exc.args) from exc
        except KeyError:
            # In case the account is deleted in the JournalDB
            return b''

    def _get_account(self,
                     address: Address,
                     from_journal: bool = True) -> Account:
        if from_journal and address in self._account_cache:
            return self._account_cache[address]

        rlp_account = self._get_encoded_account(address, from_journal)

        if rlp_account:
            account = rlp.decode(rlp_account, sedes=Account)
        else:
            account = Account()
        if from_journal:
            self._account_cache[address] = account
        return account

    def _set_account(self, address: Address, account: Account) -> None:
        self._account_cache[address] = account
        rlp_account = rlp.encode(account, sedes=Account)
        self._journaltrie[address] = rlp_account

    #
    # Record and discard API
    #
    def record(self) -> JournalDBCheckpoint:
        checkpoint = self._journaldb.record()
        self._journaltrie.record(checkpoint)

        for _, store in self._dirty_account_stores():
            store.record(checkpoint)
        return checkpoint

    def discard(self, checkpoint: JournalDBCheckpoint) -> None:
        self._journaldb.discard(checkpoint)
        self._journaltrie.discard(checkpoint)
        self._account_cache.clear()
        for _, store in self._dirty_account_stores():
            store.discard(checkpoint)

    def commit(self, checkpoint: JournalDBCheckpoint) -> None:
        self._journaldb.commit(checkpoint)
        self._journaltrie.commit(checkpoint)
        for _, store in self._dirty_account_stores():
            store.commit(checkpoint)

    def make_state_root(self) -> Hash32:
        for _, store in self._dirty_account_stores():
            store.make_storage_root()

        for address, storage_root in self._get_changed_roots():
            self.logger.debug2(
                "Updating account 0x%s to storage root 0x%s",
                address.hex(),
                storage_root.hex(),
            )
            self._set_storage_root(address, storage_root)

        self._journaldb.persist()

        diff = self._journaltrie.diff()
        # In addition to squashing (which is redundant here), this context manager causes
        # an atomic commit of the changes, so exceptions will revert the trie
        with self._trie.squash_changes() as memory_trie:
            self._apply_account_diff_without_proof(diff, memory_trie)

        self._journaltrie.reset()
        self._trie_cache.reset_cache()

        return self.state_root

    def persist(self) -> None:
        self.make_state_root()

        # persist storage
        with self._raw_store_db.atomic_batch() as write_batch:
            for address, store in self._dirty_account_stores():
                self._validate_flushed_storage(address, store)
                store.persist(write_batch)

        for address, new_root in self._get_changed_roots():
            if new_root not in self._raw_store_db and new_root != BLANK_ROOT_HASH:
                raise ValidationError(
                    "After persisting storage trie, a root node was not found. "
                    "State root for account 0x%s is missing for hash 0x%s." % (
                        address.hex(),
                        new_root.hex(),
                    ))

        # reset local storage trackers
        self._account_stores = {}
        self._dirty_accounts = set()

        # persist accounts
        self._validate_generated_root()
        new_root_hash = self.state_root
        self.logger.debug2("Persisting new state root: 0x%s",
                           new_root_hash.hex())
        with self._raw_store_db.atomic_batch() as write_batch:
            self._batchtrie.commit_to(write_batch, apply_deletes=False)
            self._batchdb.commit_to(write_batch, apply_deletes=False)
        self._root_hash_at_last_persist = new_root_hash

    def _validate_generated_root(self) -> None:
        db_diff = self._journaldb.diff()
        if len(db_diff):
            raise ValidationError(
                "AccountDB had a dirty db when it needed to be clean: %r" %
                db_diff)
        trie_diff = self._journaltrie.diff()
        if len(trie_diff):
            raise ValidationError(
                "AccountDB had a dirty trie when it needed to be clean: %r" %
                trie_diff)

    def _log_pending_accounts(self) -> None:
        diff = self._journaltrie.diff()
        for address in sorted(diff.pending_keys()):
            account = self._get_account(Address(address))
            self.logger.debug2(
                "Pending Account %s: balance %d, nonce %d, storage root %s, code hash %s",
                to_checksum_address(address),
                account.balance,
                account.nonce,
                encode_hex(account.storage_root),
                encode_hex(account.code_hash),
            )
        for deleted_address in sorted(diff.deleted_keys()):
            cast_deleted_address = Address(deleted_address)
            self.logger.debug2(
                "Deleted Account %s, empty? %s, exists? %s",
                to_checksum_address(deleted_address),
                self.account_is_empty(cast_deleted_address),
                self.account_exists(cast_deleted_address),
            )

    def _apply_account_diff_without_proof(self, diff: DBDiff,
                                          trie: BaseDB) -> None:
        """
        Apply diff of trie updates, when original nodes might be missing.
        Note that doing this naively will raise exceptions about missing nodes
        from *intermediate* trie roots. This captures exceptions and uses the previous
        trie root hash that will be recognized by other nodes.
        """
        # It's fairly common that when an account is deleted, we need to retrieve nodes
        # for accounts that were not needed during normal execution. We only need these
        # nodes to refactor the trie.
        for delete_key in diff.deleted_keys():
            try:
                del trie[delete_key]
            except trie_exceptions.MissingTrieNode as exc:
                self.logger.debug(
                    "Missing node while deleting account with key %s: %s",
                    encode_hex(delete_key),
                    exc,
                )
                raise MissingAccountTrieNode(
                    exc.missing_node_hash,
                    self._root_hash_at_last_persist,
                    exc.requested_key,
                ) from exc

        # It's fairly unusual, but possible, that setting an account will need unknown
        # nodes during a trie refactor. Here is an example that seems to cause it:
        #
        # Setup:
        #   - Root node is a branch, with 0 pointing to a leaf
        #   - The complete leaf key is (0, 1, 2), so (1, 2) is in the leaf node
        #   - We know the leaf node hash but not the leaf node body
        # Refactor that triggers missing node:
        #   - Add value with key (0, 3, 4)
        #   - We need to replace the current leaf node with a branch that points leaves at 1 and 3
        #   - The leaf for key (0, 1, 2) now contains only the (2) part, so needs to be rebuilt
        #   - We need the full body of the old (1, 2) leaf node, to rebuild

        for key, val in diff.pending_items():
            try:
                trie[key] = val
            except trie_exceptions.MissingTrieNode as exc:
                self.logger.debug(
                    "Missing node on account update key %s to %s: %s",
                    encode_hex(key),
                    encode_hex(val),
                    exc,
                )
                raise MissingAccountTrieNode(
                    exc.missing_node_hash,
                    self._root_hash_at_last_persist,
                    exc.requested_key,
                ) from exc
Beispiel #3
0
class AccountDB(AccountDatabaseAPI):
    logger = get_extended_debug_logger('eth.db.account.AccountDB')

    def __init__(self,
                 db: AtomicDatabaseAPI,
                 state_root: Hash32 = BLANK_ROOT_HASH) -> None:
        r"""
        Internal implementation details (subject to rapid change):
        Database entries go through several pipes, like so...

        .. code::

            db > _batchdb ---------------------------> _journaldb ----------------> code lookups
             \
              -> _batchtrie -> _trie -> _trie_cache -> _journaltrie --------------> account lookups

        Journaling sequesters writes at the _journal* attrs ^, until persist is called.

        _batchtrie enables us to prune all trie changes while building
        state,  without deleting old trie roots.

        _batchdb and _batchtrie together enable us to make the state root,
        without saving everything to the database.

        _journaldb is a journaling of the keys and values used to store
        code and account storage.

        _trie is a hash-trie, used to generate the state root

        _trie_cache is a cache tied to the state root of the trie. It
        is important that this cache is checked *after* looking for
        the key in _journaltrie, because the cache is only invalidated
        after a state root change.

        _journaltrie is a journaling of the accounts (an address->rlp mapping,
        rather than the nodes stored by the trie). This enables
        a squashing of all account changes before pushing them into the trie.

        .. NOTE:: StorageDB works similarly

        AccountDB synchronizes the snapshot/revert/persist of both of the
        journals.
        """
        self._raw_store_db = KeyAccessLoggerAtomicDB(db,
                                                     log_missing_keys=False)
        self._batchdb = BatchDB(self._raw_store_db)
        self._batchtrie = BatchDB(self._raw_store_db,
                                  read_through_deletes=True)
        self._journaldb = JournalDB(self._batchdb)
        self._trie = HashTrie(
            HexaryTrie(self._batchtrie, state_root, prune=True))
        self._trie_logger = KeyAccessLoggerDB(self._trie,
                                              log_missing_keys=False)
        self._trie_cache = CacheDB(self._trie_logger)
        self._journaltrie = JournalDB(self._trie_cache)
        self._account_cache = LRU(2048)
        self._account_stores: Dict[Address, AccountStorageDatabaseAPI] = {}
        self._dirty_accounts: Set[Address] = set()
        self._root_hash_at_last_persist = state_root
        self._accessed_accounts: Set[Address] = set()
        self._accessed_bytecodes: Set[Address] = set()
        # Track whether an account or slot have been accessed during a given transaction:
        self._reset_access_counters()

    @property
    def state_root(self) -> Hash32:
        return self._trie.root_hash

    @state_root.setter
    def state_root(self, value: Hash32) -> None:
        if self._trie.root_hash != value:
            self._trie_cache.reset_cache()
            self._trie.root_hash = value

    def has_root(self, state_root: bytes) -> bool:
        return state_root in self._batchtrie

    #
    # Storage
    #
    def get_storage(self,
                    address: Address,
                    slot: int,
                    from_journal: bool = True) -> int:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(slot, title="Storage Slot")

        account_store = self._get_address_store(address)
        return account_store.get(slot, from_journal)

    def set_storage(self, address: Address, slot: int, value: int) -> None:
        validate_uint256(value, title="Storage Value")
        validate_uint256(slot, title="Storage Slot")
        validate_canonical_address(address, title="Storage Address")

        account_store = self._get_address_store(address)
        self._dirty_accounts.add(address)
        account_store.set(slot, value)

    def delete_storage(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        self._set_storage_root(address, BLANK_ROOT_HASH)
        self._wipe_storage(address)

    def is_storage_warm(self, address: Address, slot: int) -> bool:
        key = self._get_storage_tracker_key(address, slot)
        return key in self._journal_accessed_state

    def mark_storage_warm(self, address: Address, slot: int) -> None:
        key = self._get_storage_tracker_key(address, slot)
        if key not in self._journal_accessed_state:
            self._journal_accessed_state[key] = IS_PRESENT_VALUE

    def _get_storage_tracker_key(self, address: Address, slot: int) -> bytes:
        """
        Get the key used to track whether a storage slot has been accessed
        during this transaction.
        """
        return address + int_to_big_endian(slot)

    def _wipe_storage(self, address: Address) -> None:
        """
        Wipe out the storage, without explicitly handling the storage root update
        """
        account_store = self._get_address_store(address)
        self._dirty_accounts.add(address)
        account_store.delete()

    def _get_address_store(self,
                           address: Address) -> AccountStorageDatabaseAPI:
        if address in self._account_stores:
            store = self._account_stores[address]
        else:
            storage_root = self._get_storage_root(address)
            store = AccountStorageDB(self._raw_store_db, storage_root, address)
            self._account_stores[address] = store
        return store

    def _dirty_account_stores(
            self) -> Iterable[Tuple[Address, AccountStorageDatabaseAPI]]:
        for address in self._dirty_accounts:
            store = self._account_stores[address]
            yield address, store

    @to_tuple
    def _get_changed_roots(self) -> Iterable[Tuple[Address, Hash32]]:
        # list all the accounts that were changed, and their new storage roots
        for address, store in self._dirty_account_stores():
            if store.has_changed_root:
                yield address, store.get_changed_root()

    def _get_storage_root(self, address: Address) -> Hash32:
        account = self._get_account(address)
        return account.storage_root

    def _set_storage_root(self, address: Address,
                          new_storage_root: Hash32) -> None:
        account = self._get_account(address)
        self._set_account(address, account.copy(storage_root=new_storage_root))

    def _validate_flushed_storage(self, address: Address,
                                  store: AccountStorageDatabaseAPI) -> None:
        if store.has_changed_root:
            actual_storage_root = self._get_storage_root(address)
            expected_storage_root = store.get_changed_root()
            if expected_storage_root != actual_storage_root:
                raise ValidationError(
                    "Storage root was not saved to account before trying to persist roots. "
                    f"Account {address!r} had storage {actual_storage_root!r}, "
                    f"but should be {expected_storage_root!r}.")

    #
    # Balance
    #
    def get_balance(self, address: Address) -> int:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.balance

    def set_balance(self, address: Address, balance: int) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(balance, title="Account Balance")

        account = self._get_account(address)
        self._set_account(address, account.copy(balance=balance))

    #
    # Nonce
    #
    def get_nonce(self, address: Address) -> int:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.nonce

    def set_nonce(self, address: Address, nonce: int) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(nonce, title="Nonce")

        account = self._get_account(address)
        self._set_account(address, account.copy(nonce=nonce))

    def increment_nonce(self, address: Address) -> None:
        current_nonce = self.get_nonce(address)
        self.set_nonce(address, current_nonce + 1)

    #
    # Code
    #
    def get_code(self, address: Address) -> bytes:
        validate_canonical_address(address, title="Storage Address")

        code_hash = self.get_code_hash(address)
        if code_hash == EMPTY_SHA3:
            return b''
        else:
            try:
                return self._journaldb[code_hash]
            except KeyError:
                raise MissingBytecode(code_hash) from KeyError
            finally:
                if code_hash in self._get_accessed_node_hashes():
                    self._accessed_bytecodes.add(address)

    def set_code(self, address: Address, code: bytes) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_is_bytes(code, title="Code")

        account = self._get_account(address)

        code_hash = keccak(code)
        self._journaldb[code_hash] = code
        self._set_account(address, account.copy(code_hash=code_hash))

    def get_code_hash(self, address: Address) -> Hash32:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.code_hash

    def delete_code(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        self._set_account(address, account.copy(code_hash=EMPTY_SHA3))

    #
    # Account Methods
    #
    def account_has_code_or_nonce(self, address: Address) -> bool:
        return self.get_nonce(address) != 0 or self.get_code_hash(
            address) != EMPTY_SHA3

    def delete_account(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        # We must wipe the storage first, because if it's the first time we load it,
        #   then we want to load it with the original storage root hash, not the
        #   empty one. (in case of a later revert, we don't want to poison the storage cache)
        self._wipe_storage(address)

        if address in self._account_cache:
            del self._account_cache[address]
        del self._journaltrie[address]

    def account_exists(self, address: Address) -> bool:
        validate_canonical_address(address, title="Storage Address")
        account_rlp = self._get_encoded_account(address, from_journal=True)
        return account_rlp != b''

    def touch_account(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        self._set_account(address, account)

    def account_is_empty(self, address: Address) -> bool:
        return not self.account_has_code_or_nonce(
            address) and self.get_balance(address) == 0

    def is_address_warm(self, address: Address) -> bool:
        return address in self._journal_accessed_state

    def mark_address_warm(self, address: Address) -> None:
        if address not in self._journal_accessed_state:
            self._journal_accessed_state[address] = IS_PRESENT_VALUE

    #
    # Internal
    #
    def _get_encoded_account(self,
                             address: Address,
                             from_journal: bool = True) -> bytes:
        self._accessed_accounts.add(address)
        lookup_trie = self._journaltrie if from_journal else self._trie_cache

        try:
            return lookup_trie[address]
        except trie_exceptions.MissingTrieNode as exc:
            raise MissingAccountTrieNode(*exc.args) from exc
        except KeyError:
            # In case the account is deleted in the JournalDB
            return b''

    def _get_account(self,
                     address: Address,
                     from_journal: bool = True) -> Account:
        if from_journal and address in self._account_cache:
            return self._account_cache[address]

        rlp_account = self._get_encoded_account(address, from_journal)

        if rlp_account:
            account = rlp.decode(rlp_account, sedes=Account)
        else:
            account = Account()
        if from_journal:
            self._account_cache[address] = account
        return account

    def _set_account(self, address: Address, account: Account) -> None:
        self._account_cache[address] = account
        rlp_account = rlp.encode(account, sedes=Account)
        self._journaltrie[address] = rlp_account

    def _reset_access_counters(self) -> None:
        # Account accesses and storage accesses recorded in the same journal
        # Accounts just use the address as the key (and an empty value as a flag)
        # Storage use a concatenation of address and slot converted to bytes (and empty value)
        self._journal_accessed_state = JournalDB(MemoryDB())

    #
    # Record and discard API
    #
    def record(self) -> JournalDBCheckpoint:
        checkpoint = self._journaldb.record()
        self._journaltrie.record(checkpoint)
        self._journal_accessed_state.record(checkpoint)

        for _, store in self._dirty_account_stores():
            store.record(checkpoint)
        return checkpoint

    def discard(self, checkpoint: JournalDBCheckpoint) -> None:
        self._journaldb.discard(checkpoint)
        self._journaltrie.discard(checkpoint)
        self._journal_accessed_state.discard(checkpoint)
        self._account_cache.clear()
        for _, store in self._dirty_account_stores():
            store.discard(checkpoint)

    def commit(self, checkpoint: JournalDBCheckpoint) -> None:
        self._journaldb.commit(checkpoint)
        self._journaltrie.commit(checkpoint)
        self._journal_accessed_state.commit(checkpoint)
        for _, store in self._dirty_account_stores():
            store.commit(checkpoint)

    def lock_changes(self) -> None:
        for _, store in self._dirty_account_stores():
            store.lock_changes()
        self._reset_access_counters()

    def make_state_root(self) -> Hash32:
        for _, store in self._dirty_account_stores():
            store.make_storage_root()

        for address, storage_root in self._get_changed_roots():
            self.logger.debug2(
                "Updating account 0x%s to storage root 0x%s",
                address.hex(),
                storage_root.hex(),
            )
            if self.account_exists(address) or storage_root != BLANK_ROOT_HASH:
                self._set_storage_root(address, storage_root)

        self._journaldb.persist()

        diff = self._journaltrie.diff()
        if diff.deleted_keys() or diff.pending_items():
            # In addition to squashing (which is redundant here), this context manager causes
            # an atomic commit of the changes, so exceptions will revert the trie
            with self._trie.squash_changes() as memory_trie:
                self._apply_account_diff_without_proof(diff, memory_trie)

        self._journaltrie.reset()
        self._trie_cache.reset_cache()

        return self.state_root

    def persist(self) -> MetaWitnessAPI:
        self.make_state_root()

        # persist storage
        with self._raw_store_db.atomic_batch() as write_batch:
            for address, store in self._dirty_account_stores():
                self._validate_flushed_storage(address, store)
                store.persist(write_batch)

        for address, new_root in self._get_changed_roots():
            if new_root is None:
                raise ValidationError(
                    f"Cannot validate new root of account 0x{address.hex()} "
                    f"which has a new root hash of None")
            elif new_root not in self._raw_store_db and new_root != BLANK_ROOT_HASH:
                raise ValidationError(
                    "After persisting storage trie, a root node was not found. "
                    f"State root for account 0x{address.hex()} "
                    f"is missing for hash 0x{new_root.hex()}.")

        # generate witness (copy) before clearing the underlying data
        meta_witness = self._get_meta_witness()

        # reset local storage trackers
        self._account_stores = {}
        self._dirty_accounts = set()
        self._accessed_accounts = set()
        self._accessed_bytecodes = set()
        # We have to clear the account cache here so that future account accesses
        #   will get added to _accessed_accounts correctly. Account accesses that
        #   are cached do not add the address to the list of accessed accounts.
        self._account_cache.clear()

        # persist accounts
        self._validate_generated_root()
        new_root_hash = self.state_root
        self.logger.debug2("Persisting new state root: 0x%s",
                           new_root_hash.hex())
        with self._raw_store_db.atomic_batch() as write_batch:
            self._batchtrie.commit_to(write_batch, apply_deletes=False)
            self._batchdb.commit_to(write_batch, apply_deletes=False)
        self._root_hash_at_last_persist = new_root_hash

        return meta_witness

    def _get_accessed_node_hashes(self) -> Set[Hash32]:
        return cast(Set[Hash32], self._raw_store_db.keys_read)

    @to_dict
    def _get_access_list(
            self) -> Iterable[Tuple[Address, AccountQueryTracker]]:
        """
        Get the list of addresses that were accessed, whether the bytecode was accessed, and
        which storage slots were accessed.
        """
        for address in self._accessed_accounts:
            did_access_bytecode = address in self._accessed_bytecodes
            if address in self._account_stores:
                accessed_storage_slots = self._account_stores[
                    address].get_accessed_slots()
            else:
                accessed_storage_slots = frozenset()
            yield address, AccountQueryTracker(did_access_bytecode,
                                               accessed_storage_slots)

    def _get_meta_witness(self) -> MetaWitness:
        """
        Get a variety of metadata about the state witness needed to execute the block.

        This creates a copy, so that underlying changes do not affect the returned MetaWitness.
        """
        return MetaWitness(self._get_accessed_node_hashes(),
                           self._get_access_list())

    def _validate_generated_root(self) -> None:
        db_diff = self._journaldb.diff()
        if len(db_diff):
            raise ValidationError(
                f"AccountDB had a dirty db when it needed to be clean: {db_diff!r}"
            )
        trie_diff = self._journaltrie.diff()
        if len(trie_diff):
            raise ValidationError(
                f"AccountDB had a dirty trie when it needed to be clean: {trie_diff!r}"
            )

    def _log_pending_accounts(self) -> None:
        # This entire method is about debug2 logging, so skip it if debug2 is disabled
        if not self.logger.show_debug2:
            return

        diff = self._journaltrie.diff()
        for address in sorted(diff.pending_keys()):
            account = self._get_account(Address(address))
            self.logger.debug2(
                "Pending Account %s: balance %d, nonce %d, storage root %s, code hash %s",
                to_checksum_address(address),
                account.balance,
                account.nonce,
                encode_hex(account.storage_root),
                encode_hex(account.code_hash),
            )
        for deleted_address in sorted(diff.deleted_keys()):
            # Check if the account was accessed before accessing/logging info about the address
            was_account_accessed = deleted_address in self._accessed_accounts
            cast_deleted_address = Address(deleted_address)
            self.logger.debug2(
                "Deleted Account %s, empty? %s, exists? %s",
                to_checksum_address(deleted_address),
                self.account_is_empty(cast_deleted_address),
                self.account_exists(cast_deleted_address),
            )
            # If the account was not accessed previous to the log, (re)mark it as not accessed
            if not was_account_accessed:
                self._accessed_accounts.remove(cast_deleted_address)

    def _apply_account_diff_without_proof(self, diff: DBDiff,
                                          trie: DatabaseAPI) -> None:
        """
        Apply diff of trie updates, when original nodes might be missing.
        Note that doing this naively will raise exceptions about missing nodes
        from *intermediate* trie roots. This captures exceptions and uses the previous
        trie root hash that will be recognized by other nodes.
        """
        # It's fairly common that when an account is deleted, we need to retrieve nodes
        # for accounts that were not needed during normal execution. We only need these
        # nodes to refactor the trie.
        for delete_key in diff.deleted_keys():
            try:
                del trie[delete_key]
            except trie_exceptions.MissingTrieNode as exc:
                self.logger.debug(
                    "Missing node while deleting account with key %s: %s",
                    encode_hex(delete_key),
                    exc,
                )
                raise MissingAccountTrieNode(
                    exc.missing_node_hash,
                    self._root_hash_at_last_persist,
                    exc.requested_key,
                ) from exc

        # It's fairly unusual, but possible, that setting an account will need unknown
        # nodes during a trie refactor. Here is an example that seems to cause it:
        #
        # Setup:
        #   - Root node is a branch, with 0 pointing to a leaf
        #   - The complete leaf key is (0, 1, 2), so (1, 2) is in the leaf node
        #   - We know the leaf node hash but not the leaf node body
        # Refactor that triggers missing node:
        #   - Add value with key (0, 3, 4)
        #   - We need to replace the current leaf node with a branch that points leaves at 1 and 3
        #   - The leaf for key (0, 1, 2) now contains only the (2) part, so needs to be rebuilt
        #   - We need the full body of the old (1, 2) leaf node, to rebuild

        for key, val in diff.pending_items():
            try:
                trie[key] = val
            except trie_exceptions.MissingTrieNode as exc:
                self.logger.debug(
                    "Missing node on account update key %s to %s: %s",
                    encode_hex(key),
                    encode_hex(val),
                    exc,
                )
                raise MissingAccountTrieNode(
                    exc.missing_node_hash,
                    self._root_hash_at_last_persist,
                    exc.requested_key,
                ) from exc
Beispiel #4
0
class StorageLookup(BaseDB):
    """
    This lookup converts lookups of storage slot integers into the appropriate trie lookup.
    Similarly, it persists changes to the appropriate trie at write time.

    StorageLookup also tracks the state roots changed since the last persist.
    """
    logger = get_extended_debug_logger("eth.db.storage.StorageLookup")

    def __init__(self, db: DatabaseAPI, storage_root: Hash32, address: Address) -> None:
        self._db = db
        self._starting_root_hash = storage_root
        self._address = address
        self._write_trie = None
        self._trie_nodes_batch: BatchDB = None

    def _get_write_trie(self) -> HexaryTrie:
        if self._trie_nodes_batch is None:
            self._trie_nodes_batch = BatchDB(self._db, read_through_deletes=True)

        if self._write_trie is None:
            batch_db = self._trie_nodes_batch
            self._write_trie = HexaryTrie(batch_db, root_hash=self._starting_root_hash, prune=True)

        return self._write_trie

    def _get_read_trie(self) -> HexaryTrie:
        if self._write_trie is not None:
            return self._write_trie
        else:
            # Creating "HexaryTrie" is a pretty light operation, so not a huge cost
            # to create a new one at every read, but we could
            # cache the read trie, if this becomes a bottleneck.
            return HexaryTrie(self._db, root_hash=self._starting_root_hash)

    def _decode_key(self, key: bytes) -> bytes:
        padded_slot = pad32(key)
        return keccak(padded_slot)

    def __getitem__(self, key: bytes) -> bytes:
        hashed_slot = self._decode_key(key)
        read_trie = self._get_read_trie()
        try:
            return read_trie[hashed_slot]
        except trie_exceptions.MissingTrieNode as exc:
            raise MissingStorageTrieNode(
                exc.missing_node_hash,
                self._starting_root_hash,
                exc.requested_key,
                self._address,
            ) from exc

    def __setitem__(self, key: bytes, value: bytes) -> None:
        hashed_slot = self._decode_key(key)
        write_trie = self._get_write_trie()
        write_trie[hashed_slot] = value

    def _exists(self, key: bytes) -> bool:
        # used by BaseDB for __contains__ checks
        hashed_slot = self._decode_key(key)
        read_trie = self._get_read_trie()
        return hashed_slot in read_trie

    def __delitem__(self, key: bytes) -> None:
        hashed_slot = self._decode_key(key)
        write_trie = self._get_write_trie()
        try:
            del write_trie[hashed_slot]
        except trie_exceptions.MissingTrieNode as exc:
            raise MissingStorageTrieNode(
                exc.missing_node_hash,
                self._starting_root_hash,
                exc.requested_key,
                self._address,
            ) from exc

    @property
    def has_changed_root(self) -> bool:
        return self._write_trie and self._write_trie.root_hash != self._starting_root_hash

    def get_changed_root(self) -> Hash32:
        if self._write_trie is not None:
            return self._write_trie.root_hash
        else:
            raise ValidationError("Asked for changed root when no writes have been made")

    def _clear_changed_root(self) -> None:
        self._write_trie = None
        self._trie_nodes_batch = None
        self._starting_root_hash = None

    def commit_to(self, db: DatabaseAPI) -> None:
        """
        Trying to commit changes when nothing has been written will raise a
        ValidationError
        """
        self.logger.debug2('persist storage root to data store')
        if self._trie_nodes_batch is None:
            raise ValidationError(
                "It is invalid to commit an account's storage if it has no pending changes. "
                "Always check storage_lookup.has_changed_root before attempting to commit."
            )
        self._trie_nodes_batch.commit_to(db, apply_deletes=False)
        self._clear_changed_root()
Beispiel #5
0
class AccountDB(BaseAccountDB):

    logger = cast(ExtendedDebugLogger, logging.getLogger('eth.db.account.AccountDB'))

    def __init__(self, db: BaseAtomicDB, state_root: Hash32=BLANK_ROOT_HASH) -> None:
        r"""
        Internal implementation details (subject to rapid change):
        Database entries go through several pipes, like so...

        .. code::

            db > _batchdb ---------------------------> _journaldb ----------------> code lookups
             \
              -> _batchtrie -> _trie -> _trie_cache -> _journaltrie --------------> account lookups

        Journaling sequesters writes at the _journal* attrs ^, until persist is called.

        _batchtrie enables us to prune all trie changes while building
        state,  without deleting old trie roots.

        _batchdb and _batchtrie together enable us to make the state root,
        without saving everything to the database.

        _journaldb is a journaling of the keys and values used to store
        code and account storage.

        _trie is a hash-trie, used to generate the state root

        _trie_cache is a cache tied to the state root of the trie. It
        is important that this cache is checked *after* looking for
        the key in _journaltrie, because the cache is only invalidated
        after a state root change.

        _journaltrie is a journaling of the accounts (an address->rlp mapping,
        rather than the nodes stored by the trie). This enables
        a squashing of all account changes before pushing them into the trie.

        .. NOTE:: StorageDB works similarly

        AccountDB synchronizes the snapshot/revert/persist of both of the
        journals.
        """
        self._raw_store_db = db
        self._batchdb = BatchDB(db)
        self._batchtrie = BatchDB(db)
        self._journaldb = JournalDB(self._batchdb)
        self._trie = HashTrie(HexaryTrie(self._batchtrie, state_root, prune=True))
        self._trie_cache = CacheDB(self._trie)
        self._journaltrie = JournalDB(self._trie_cache)
        self._account_cache = LRU(2048)
        self._account_stores = {}  # type: Dict[Address, AccountStorageDB]
        self._dirty_accounts = set()  # type: Set[Address]

    @property
    def state_root(self) -> Hash32:
        return self._trie.root_hash

    @state_root.setter
    def state_root(self, value: Hash32) -> None:
        if self._trie.root_hash != value:
            self._trie_cache.reset_cache()
            self._trie.root_hash = value

    def has_root(self, state_root: bytes) -> bool:
        return state_root in self._batchtrie

    #
    # Storage
    #
    def get_storage(self, address: Address, slot: int, from_journal: bool=True) -> int:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(slot, title="Storage Slot")

        account_store = self._get_address_store(address)
        return account_store.get(slot, from_journal)

    def set_storage(self, address: Address, slot: int, value: int) -> None:
        validate_uint256(value, title="Storage Value")
        validate_uint256(slot, title="Storage Slot")
        validate_canonical_address(address, title="Storage Address")

        account_store = self._get_address_store(address)
        self._dirty_accounts.add(address)
        account_store.set(slot, value)

    def delete_storage(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        self._set_storage_root(address, BLANK_ROOT_HASH)
        self._wipe_storage(address)

    def _wipe_storage(self, address: Address) -> None:
        """
        Wipe out the storage, without explicitly handling the storage root update
        """
        account_store = self._get_address_store(address)
        self._dirty_accounts.add(address)
        account_store.delete()

    def _get_address_store(self, address: Address) -> AccountStorageDB:
        if address in self._account_stores:
            store = self._account_stores[address]
        else:
            storage_root = self._get_storage_root(address)
            store = AccountStorageDB(self._raw_store_db, storage_root, address)
            self._account_stores[address] = store
        return store

    def _dirty_account_stores(self) -> Iterable[Tuple[Address, AccountStorageDB]]:
        for address in self._dirty_accounts:
            store = self._account_stores[address]
            yield address, store

    @to_tuple
    def _get_changed_roots(self) -> Iterable[Tuple[Address, Hash32]]:
        # list all the accounts that were changed, and their new storage roots
        for address, store in self._dirty_account_stores():
            if store.has_changed_root:
                yield address, store.get_changed_root()

    def _get_storage_root(self, address: Address) -> Hash32:
        account = self._get_account(address)
        return account.storage_root

    def _set_storage_root(self, address: Address, new_storage_root: Hash32) -> None:
        account = self._get_account(address)
        self._set_account(address, account.copy(storage_root=new_storage_root))

    def _validate_flushed_storage(self, address: Address, store: AccountStorageDB) -> None:
        if store.has_changed_root:
            actual_storage_root = self._get_storage_root(address)
            expected_storage_root = store.get_changed_root()
            if expected_storage_root != actual_storage_root:
                raise ValidationError(
                    "Storage root was not saved to account before trying to persist roots. "
                    "Account %r had storage %r, but should be %r." % (
                        address,
                        actual_storage_root,
                        expected_storage_root,
                    )
                )

    #
    # Balance
    #
    def get_balance(self, address: Address) -> int:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.balance

    def set_balance(self, address: Address, balance: int) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(balance, title="Account Balance")

        account = self._get_account(address)
        self._set_account(address, account.copy(balance=balance))

    #
    # Nonce
    #
    def get_nonce(self, address: Address) -> int:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.nonce

    def set_nonce(self, address: Address, nonce: int) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_uint256(nonce, title="Nonce")

        account = self._get_account(address)
        self._set_account(address, account.copy(nonce=nonce))

    def increment_nonce(self, address: Address) -> None:
        current_nonce = self.get_nonce(address)
        self.set_nonce(address, current_nonce + 1)

    #
    # Code
    #
    def get_code(self, address: Address) -> bytes:
        validate_canonical_address(address, title="Storage Address")

        try:
            return self._journaldb[self.get_code_hash(address)]
        except KeyError:
            return b""

    def set_code(self, address: Address, code: bytes) -> None:
        validate_canonical_address(address, title="Storage Address")
        validate_is_bytes(code, title="Code")

        account = self._get_account(address)

        code_hash = keccak(code)
        self._journaldb[code_hash] = code
        self._set_account(address, account.copy(code_hash=code_hash))

    def get_code_hash(self, address: Address) -> Hash32:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        return account.code_hash

    def delete_code(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        self._set_account(address, account.copy(code_hash=EMPTY_SHA3))

    #
    # Account Methods
    #
    def account_has_code_or_nonce(self, address: Address) -> bool:
        return self.get_nonce(address) != 0 or self.get_code_hash(address) != EMPTY_SHA3

    def delete_account(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        if address in self._account_cache:
            del self._account_cache[address]
        del self._journaltrie[address]

        self._wipe_storage(address)

    def account_exists(self, address: Address) -> bool:
        validate_canonical_address(address, title="Storage Address")
        return self._journaltrie.get(address, b'') != b''

    def touch_account(self, address: Address) -> None:
        validate_canonical_address(address, title="Storage Address")

        account = self._get_account(address)
        self._set_account(address, account)

    def account_is_empty(self, address: Address) -> bool:
        return not self.account_has_code_or_nonce(address) and self.get_balance(address) == 0

    #
    # Internal
    #
    def _get_account(self, address: Address, from_journal: bool=True) -> Account:
        if from_journal and address in self._account_cache:
            return self._account_cache[address]
        rlp_account = (self._journaltrie if from_journal else self._trie_cache).get(address, b'')
        if rlp_account:
            account = rlp.decode(rlp_account, sedes=Account)
        else:
            account = Account()
        if from_journal:
            self._account_cache[address] = account
        return account

    def _set_account(self, address: Address, account: Account) -> None:
        self._account_cache[address] = account
        rlp_account = rlp.encode(account, sedes=Account)
        self._journaltrie[address] = rlp_account

    #
    # Record and discard API
    #
    def record(self) -> UUID:
        changeset_id = self._journaldb.record()
        self._journaltrie.record(changeset_id)

        for _, store in self._dirty_account_stores():
            store.record(changeset_id)
        return changeset_id

    def discard(self, changeset: UUID) -> None:
        self._journaldb.discard(changeset)
        self._journaltrie.discard(changeset)
        self._account_cache.clear()
        for _, store in self._dirty_account_stores():
            store.discard(changeset)

    def commit(self, changeset: UUID) -> None:
        self._journaldb.commit(changeset)
        self._journaltrie.commit(changeset)
        for _, store in self._dirty_account_stores():
            store.commit(changeset)

    def make_state_root(self) -> Hash32:
        for _, store in self._dirty_account_stores():
            store.make_storage_root()

        for address, storage_root in self._get_changed_roots():
            self.logger.debug2(
                "Updating account 0x%s to storage root 0x%s",
                address.hex(),
                storage_root.hex(),
            )
            self._set_storage_root(address, storage_root)

        self._journaldb.persist()
        self._journaltrie.persist()
        return self.state_root

    def persist(self) -> None:
        self.make_state_root()

        # persist storage
        with self._raw_store_db.atomic_batch() as write_batch:
            for address, store in self._dirty_account_stores():
                self._validate_flushed_storage(address, store)
                store.persist(write_batch)

        for address, new_root in self._get_changed_roots():
            if new_root not in self._raw_store_db and new_root != BLANK_ROOT_HASH:
                raise ValidationError(
                    "After persisting storage trie, a root node was not found. "
                    "State root for account 0x%s is missing for hash 0x%s." % (
                        address.hex(),
                        new_root.hex(),
                    )
                )

        # reset local storage trackers
        self._account_stores = {}
        self._dirty_accounts = set()

        # persist accounts
        self._validate_generated_root()
        with self._raw_store_db.atomic_batch() as write_batch:
            self._batchtrie.commit_to(write_batch, apply_deletes=False)
            self._batchdb.commit_to(write_batch, apply_deletes=False)

    def _validate_generated_root(self) -> None:
        db_diff = self._journaldb.diff()
        if len(db_diff):
            raise ValidationError(
                "AccountDB had a dirty db when it needed to be clean: %r" % db_diff
            )
        trie_diff = self._journaltrie.diff()
        if len(trie_diff):
            raise ValidationError(
                "AccountDB had a dirty trie when it needed to be clean: %r" % trie_diff
            )

    def _log_pending_accounts(self) -> None:
        accounts_displayed = set()  # type: Set[bytes]
        queued_changes = self._journaltrie.journal.journal_data.items()
        # mypy bug for ordered dict reversibility: https://github.com/python/typeshed/issues/2078
        for _, accounts in reversed(queued_changes):
            for address in accounts:
                if address in accounts_displayed:
                    continue
                else:
                    accounts_displayed.add(address)
                    account = self._get_account(Address(address))
                    self.logger.debug2(
                        "Account %s: balance %d, nonce %d, storage root %s, code hash %s",
                        encode_hex(address),
                        account.balance,
                        account.nonce,
                        encode_hex(account.storage_root),
                        encode_hex(account.code_hash),
                    )