diff options
Diffstat (limited to 'synapse/storage/database.py')
| -rw-r--r-- | synapse/storage/database.py | 50 |
1 files changed, 46 insertions, 4 deletions
diff --git a/synapse/storage/database.py b/synapse/storage/database.py index 3b44e6469c..a219999f15 100644 --- a/synapse/storage/database.py +++ b/synapse/storage/database.py @@ -13,8 +13,10 @@ # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. +import inspect import logging import time +import types from collections import defaultdict from sys import intern from time import monotonic as monotonic_time @@ -526,6 +528,12 @@ class DatabasePool: the function will correctly handle being aborted and retried half way through its execution. + Similarly, the arguments to `func` (`args`, `kwargs`) should not be generators, + since they could be evaluated multiple times (which would produce an empty + result on the second or subsequent evaluation). Likewise, the closure of `func` + must not reference any generators. This method attempts to detect such usage + and will log an error. + Args: conn desc @@ -536,6 +544,39 @@ class DatabasePool: **kwargs """ + # Robustness check: ensure that none of the arguments are generators, since that + # will fail if we have to repeat the transaction. + # For now, we just log an error, and hope that it works on the first attempt. + # TODO: raise an exception. + for i, arg in enumerate(args): + if inspect.isgenerator(arg): + logger.error( + "Programming error: generator passed to new_transaction as " + "argument %i to function %s", + i, + func, + ) + for name, val in kwargs.items(): + if inspect.isgenerator(val): + logger.error( + "Programming error: generator passed to new_transaction as " + "argument %s to function %s", + name, + func, + ) + # also check variables referenced in func's closure + if inspect.isfunction(func): + f = cast(types.FunctionType, func) + if f.__closure__: + for i, cell in enumerate(f.__closure__): + if inspect.isgenerator(cell.cell_contents): + logger.error( + "Programming error: function %s references generator %s " + "via its closure", + f, + f.__code__.co_freevars[i], + ) + start = monotonic_time() txn_id = self._TXN_ID @@ -1226,9 +1267,9 @@ class DatabasePool: self, table: str, key_names: Collection[str], - key_values: Collection[Iterable[Any]], + key_values: Collection[Collection[Any]], value_names: Collection[str], - value_values: Iterable[Iterable[Any]], + value_values: Collection[Collection[Any]], desc: str, ) -> None: """ @@ -1920,7 +1961,7 @@ class DatabasePool: self, table: str, column: str, - iterable: Iterable[Any], + iterable: Collection[Any], keyvalues: Dict[str, Any], desc: str, ) -> int: @@ -1931,7 +1972,8 @@ class DatabasePool: Args: table: string giving the table name column: column name to test for inclusion against `iterable` - iterable: list + iterable: list of values to match against `column`. NB cannot be a generator + as it may be evaluated multiple times. keyvalues: dict of column names and values to select the rows with desc: description of the transaction, for logging and metrics |