def test_batch_db_read_through_should_fail_to_commit_deletes(base_db):
batch_db = BatchDB(base_db, read_through_deletes=True)
# When a batch_db is reading through it's deletes, those deletes
# should never be applied. It's nonsense
with pytest.raises(ValidationError):
batch_db.commit(apply_deletes=True)
def test_batch_db_read_through_delete_after_modify(base_db):
base_db[b'modify-then-delete'] = b'original'
batch_db = BatchDB(base_db, read_through_deletes=True)
batch_db.set(b'modify-then-delete', b'new-val')
assert batch_db[b'modify-then-delete'] == b'new-val'
batch_db.delete(b'modify-then-delete')
assert batch_db[b'modify-then-delete'] == b'original'
batch_db.commit(apply_deletes=False)
assert base_db[b'modify-then-delete'] == b'original'
def test_batch_db_read_through_delete(base_db):
base_db[b'read-through-deleted'] = b'still-here'
batch_db = BatchDB(base_db, read_through_deletes=True)
batch_db.set(b'only-in-batch', b'will-disappear')
batch_db.delete(b'read-through-deleted')
batch_db.delete(b'only-in-batch')
assert b'read-through-deleted' in batch_db
assert batch_db[b'read-through-deleted'] == b'still-here'
assert b'only-in-batch' not in batch_db
with pytest.raises(KeyError):
batch_db[b'only-in-batch']
batch_db.commit(apply_deletes=False)
assert base_db[b'read-through-deleted'] == b'still-here'
# deleted batch data should never get pushed to the underlying
assert b'only-in-batch' not in base_db
class AccountDB(BaseAccountDB):
logger = cast(ExtendedDebugLogger,
logging.getLogger('eth.db.account.AccountDB'))
def __init__(self,
db: BaseDB,
state_root: Hash32 = BLANK_ROOT_HASH) -> None:
r"""
Internal implementation details (subject to rapid change):
Database entries go through several pipes, like so...
.. code::
-> hash-trie -> storage lookups
/
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:: There is an opportunity to do something similar for storage
AccountDB synchronizes the snapshot/revert/persist of both of the
journals.
"""
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)
@property
def state_root(self) -> Hash32:
return self._trie.root_hash
@state_root.setter
def state_root(self, value: Hash32) -> None:
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 = self._get_account(address, from_journal)
storage = HashTrie(HexaryTrie(self._journaldb, account.storage_root))
slot_as_key = pad32(int_to_big_endian(slot))
if slot_as_key in storage:
encoded_value = storage[slot_as_key]
return rlp.decode(encoded_value, sedes=rlp.sedes.big_endian_int)
else:
return 0
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 = self._get_account(address)
storage = HashTrie(HexaryTrie(self._journaldb, account.storage_root))
slot_as_key = pad32(int_to_big_endian(slot))
if value:
encoded_value = rlp.encode(value)
storage[slot_as_key] = encoded_value
else:
del storage[slot_as_key]
self._set_account(address,
account.copy(storage_root=storage.root_hash))
def delete_storage(self, address: Address) -> None:
validate_canonical_address(address, title="Storage Address")
account = self._get_account(address)
self._set_account(address, account.copy(storage_root=BLANK_ROOT_HASH))
#
# 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]
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) -> Tuple[UUID, UUID]:
return (self._journaldb.record(), self._journaltrie.record())
def discard(self, changeset: Tuple[UUID, UUID]) -> None:
db_changeset, trie_changeset = changeset
self._journaldb.discard(db_changeset)
self._journaltrie.discard(trie_changeset)
self._account_cache.clear()
def commit(self, changeset: Tuple[UUID, UUID]) -> None:
db_changeset, trie_changeset = changeset
self._journaldb.commit(db_changeset)
self._journaltrie.commit(trie_changeset)
def make_state_root(self) -> Hash32:
self.logger.debug2("Generating AccountDB trie")
self._journaldb.persist()
self._journaltrie.persist()
return self.state_root
def persist(self) -> None:
self.make_state_root()
self._batchtrie.commit(apply_deletes=False)
self._batchdb.commit(apply_deletes=True)
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),
)
class AccountStorageDB(AccountStorageDatabaseAPI):
logger = get_extended_debug_logger("eth.db.storage.AccountStorageDB")
def __init__(self, db: AtomicDatabaseAPI, storage_root: Hash32, address: Address) -> None:
"""
Database entries go through several pipes, like so...
.. code::
db -> _storage_lookup -> _storage_cache -> _locked_changes -> _journal_storage
db is the raw database, we can assume it hits disk when written to.
Keys are stored as node hashes and rlp-encoded node values.
_storage_lookup is itself a pair of databases: (BatchDB -> HexaryTrie),
writes to storage lookup *are* immeditaely applied to a trie, generating
the appropriate trie nodes and and root hash (via the HexaryTrie). The
writes are *not* persisted to db, until _storage_lookup is explicitly instructed to,
via :meth:`StorageLookup.commit_to`
_storage_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 _journal_storage, because the cache is only invalidated
after a state root change. Otherwise, you will see data since the last
storage root was calculated.
_locked_changes is a batch database that includes only those values that are
un-revertable in the EVM. Currently, that means changes that completed in a
previous transaction.
Journaling batches writes at the _journal_storage layer, until persist is called.
It manages all the checkpointing and rollbacks that happen during EVM execution.
In both _storage_cache and _journal_storage, Keys are set/retrieved as the
big_endian encoding of the slot integer, and the rlp-encoded value.
"""
self._address = address
self._storage_lookup = StorageLookup(db, storage_root, address)
self._storage_cache = CacheDB(self._storage_lookup)
self._locked_changes = BatchDB(self._storage_cache)
self._journal_storage = JournalDB(self._locked_changes)
def get(self, slot: int, from_journal: bool=True) -> int:
key = int_to_big_endian(slot)
lookup_db = self._journal_storage if from_journal else self._locked_changes
try:
encoded_value = lookup_db[key]
except MissingStorageTrieNode:
raise
except KeyError:
return 0
if encoded_value == b'':
return 0
else:
return rlp.decode(encoded_value, sedes=rlp.sedes.big_endian_int)
def set(self, slot: int, value: int) -> None:
key = int_to_big_endian(slot)
if value:
self._journal_storage[key] = rlp.encode(value)
else:
del self._journal_storage[key]
def delete(self) -> None:
self.logger.debug2(
"Deleting all storage in account 0x%s, hashed 0x%s",
self._address.hex(),
keccak(self._address).hex(),
)
self._journal_storage.clear()
self._storage_cache.reset_cache()
def record(self, checkpoint: JournalDBCheckpoint) -> None:
self._journal_storage.record(checkpoint)
def discard(self, checkpoint: JournalDBCheckpoint) -> None:
self.logger.debug2('discard checkpoint %r', checkpoint)
if self._journal_storage.has_checkpoint(checkpoint):
self._journal_storage.discard(checkpoint)
else:
# if the checkpoint comes before this account started tracking,
# then simply reset to the beginning
self._journal_storage.reset()
self._storage_cache.reset_cache()
def commit(self, checkpoint: JournalDBCheckpoint) -> None:
if self._journal_storage.has_checkpoint(checkpoint):
self._journal_storage.commit(checkpoint)
else:
# if the checkpoint comes before this account started tracking,
# then flatten all changes, without persisting
self._journal_storage.flatten()
def lock_changes(self) -> None:
self._journal_storage.persist()
def make_storage_root(self) -> None:
self.lock_changes()
self._locked_changes.commit(apply_deletes=True)
def _validate_flushed(self) -> None:
"""
Will raise an exception if there are some changes made since the last persist.
"""
journal_diff = self._journal_storage.diff()
if len(journal_diff) > 0:
raise ValidationError(
f"StorageDB had a dirty journal when it needed to be clean: {journal_diff!r}"
)
@property
def has_changed_root(self) -> bool:
return self._storage_lookup.has_changed_root
def get_changed_root(self) -> Hash32:
return self._storage_lookup.get_changed_root()
def persist(self, db: DatabaseAPI) -> None:
self._validate_flushed()
if self._storage_lookup.has_changed_root:
self._storage_lookup.commit_to(db)
