예제 #1
0
파일: storage.py 프로젝트: veox/py-evm
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)
예제 #2
0
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 = JournalDB(self._storage_cache)
        self._journal_storage = JournalDB(self._locked_changes)

        # Track how many times we have cleared the storage. This is journaled
        # in lockstep with other storage changes. That way, we can detect if a revert
        # causes use to revert past the previous storage deletion. The clear count is used
        # as an index to find the base trie from before the revert.
        self._clear_count = JournalDB(
            MemoryDB({CLEAR_COUNT_KEY_NAME: to_bytes(0)}))

    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:
            try:
                current_val = self._journal_storage[key]
            except KeyError:
                # deleting an empty key has no effect
                return
            else:
                if current_val != b'':
                    # only try to delete the value if it's present
                    del self._journal_storage[key]

    def delete(self) -> None:
        self.logger.debug2(
            "Deleting all storage in account 0x%s",
            self._address.hex(),
        )
        self._journal_storage.clear()
        self._storage_cache.reset_cache()

        # Empty out the storage lookup trie (keeping history, in case of a revert)
        new_clear_count = self._storage_lookup.new_trie()

        # Look up the previous count of how many times the account has been deleted.
        # This can happen multiple times in one block, via CREATE2.
        old_clear_count = to_int(self._clear_count[CLEAR_COUNT_KEY_NAME])

        # Gut check that we have incremented correctly
        if new_clear_count != old_clear_count + 1:
            raise ValidationError(
                f"Must increase clear count by one on each delete. Instead, went from"
                f" {old_clear_count} -> {new_clear_count} in account 0x{self._address.hex()}"
            )

        # Save the new count, ie~ the index used for a future revert.
        self._clear_count[CLEAR_COUNT_KEY_NAME] = to_bytes(new_clear_count)

    def record(self, checkpoint: JournalDBCheckpoint) -> None:
        self._journal_storage.record(checkpoint)
        self._clear_count.record(checkpoint)

    def discard(self, checkpoint: JournalDBCheckpoint) -> None:
        self.logger.debug2('discard checkpoint %r', checkpoint)
        latest_clear_count = to_int(self._clear_count[CLEAR_COUNT_KEY_NAME])

        if self._journal_storage.has_checkpoint(checkpoint):
            self._journal_storage.discard(checkpoint)
            self._clear_count.discard(checkpoint)
        else:
            # if the checkpoint comes before this account started tracking,
            #    then simply reset to the beginning
            self._journal_storage.reset()
            self._clear_count.reset()
        self._storage_cache.reset_cache()

        reverted_clear_count = to_int(self._clear_count[CLEAR_COUNT_KEY_NAME])

        if reverted_clear_count == latest_clear_count - 1:
            # This revert rewinds past a trie deletion, so roll back to the trie at
            #   that point. We use the clear count as an index to get back to the
            #   old base trie.
            self._storage_lookup.rollback_trie(reverted_clear_count)
        elif reverted_clear_count == latest_clear_count:
            # No change in the base trie, take no action
            pass
        else:
            # Although CREATE2 permits multiple creates and deletes in a single block,
            #   you can still only revert across a single delete. That's because delete
            #   is only triggered at the end of the transaction.
            raise ValidationError(
                f"This revert has changed the clear count in an invalid way, from"
                f" {latest_clear_count} to {reverted_clear_count}, in 0x{self._address.hex()}"
            )

    def commit(self, checkpoint: JournalDBCheckpoint) -> None:
        if self._journal_storage.has_checkpoint(checkpoint):
            self._journal_storage.commit(checkpoint)
            self._clear_count.commit(checkpoint)
        else:
            # if the checkpoint comes before this account started tracking,
            #    then flatten all changes, without persisting
            self._journal_storage.flatten()
            self._clear_count.flatten()

    def lock_changes(self) -> None:
        if self._journal_storage.has_clear():
            self._locked_changes.clear()
        self._journal_storage.persist()

    def make_storage_root(self) -> None:
        self.lock_changes()
        self._locked_changes.persist()

    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)
class JournalComparison(RuleBasedStateMachine):
    """
    Compare an older version of JournalDB against a newer, optimized one.
    """
    def __init__(self):
        super().__init__()
        self.slow_wrapped = {}
        self.slow_journal = SlowJournalDB(self.slow_wrapped)
        self.fast_wrapped = {}
        self.fast_journal = JournalDB(self.fast_wrapped)

    keys = Bundle('keys')
    values = Bundle('values')
    checkpoints = Bundle('checkpoints')

    @rule(target=keys, k=st.binary())
    def add_key(self, k):
        return k

    @rule(target=values, v=st.binary())
    def add_value(self, v):
        return v

    @rule(target=checkpoints)
    def record(self):
        slow_checkpoint = self.slow_journal.record()
        fast_checkpoint = self.fast_journal.record()
        assert self.slow_journal.diff() == self.fast_journal.diff()
        return slow_checkpoint, fast_checkpoint

    @rule(k=keys, v=values)
    def set(self, k, v):
        self.slow_journal[k] = v
        self.fast_journal[k] = v
        assert self.slow_journal.diff() == self.fast_journal.diff()

    @rule(k=keys)
    def delete(self, k):
        if k not in self.slow_journal:
            assert k not in self.fast_journal
            return
        else:
            del self.slow_journal[k]
            del self.fast_journal[k]
            assert self.slow_journal.diff() == self.fast_journal.diff()

    @rule(c=checkpoints)
    def commit(self, c):
        slow_checkpoint, fast_checkpoint = c
        if not self.slow_journal.has_changeset(slow_checkpoint):
            assert not self.fast_journal.has_checkpoint(fast_checkpoint)
            return
        else:
            self.slow_journal.commit(slow_checkpoint)
            self.fast_journal.commit(fast_checkpoint)
            assert self.slow_journal.diff() == self.fast_journal.diff()

    @rule(c=checkpoints)
    def discard(self, c):
        slow_checkpoint, fast_checkpoint = c
        if not self.slow_journal.has_changeset(slow_checkpoint):
            assert not self.fast_journal.has_checkpoint(fast_checkpoint)
        else:
            self.slow_journal.discard(slow_checkpoint)
            self.fast_journal.discard(fast_checkpoint)
            assert self.slow_journal.diff() == self.fast_journal.diff()

    @rule()
    def flatten(self):
        self.slow_journal.flatten()
        self.fast_journal.flatten()
        assert self.slow_journal.diff() == self.fast_journal.diff()

    @rule()
    def persist(self):
        self.slow_journal.persist()
        self.fast_journal.persist()
        assert self.slow_wrapped == self.fast_wrapped