diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/storage/database.py | 10 | ||||
| -rw-r--r-- | synapse/storage/engines/_base.py | 19 | ||||
| -rw-r--r-- | synapse/storage/engines/postgres.py | 29 | ||||
| -rw-r--r-- | synapse/storage/engines/sqlite.py | 7 |
4 files changed, 60 insertions, 5 deletions
diff --git a/synapse/storage/database.py b/synapse/storage/database.py index 57cc1d76e0..7455326ed3 100644 --- a/synapse/storage/database.py +++ b/synapse/storage/database.py @@ -702,6 +702,7 @@ class DatabasePool: func: Callable[..., R], *args: Any, db_autocommit: bool = False, + isolation_level: Optional[int] = None, **kwargs: Any, ) -> R: """Starts a transaction on the database and runs a given function @@ -724,6 +725,7 @@ class DatabasePool: called multiple times if the transaction is retried, so must correctly handle that case. + isolation_level: Set the server isolation level for this transaction. args: positional args to pass to `func` kwargs: named args to pass to `func` @@ -763,6 +765,7 @@ class DatabasePool: func: Callable[..., R], *args: Any, db_autocommit: bool = False, + isolation_level: Optional[int] = None, **kwargs: Any, ) -> R: """Wraps the .runWithConnection() method on the underlying db_pool. @@ -775,6 +778,7 @@ class DatabasePool: db_autocommit: Whether to run the function in "autocommit" mode, i.e. outside of a transaction. This is useful for transaction that are only a single query. Currently only affects postgres. + isolation_level: Set the server isolation level for this transaction. kwargs: named args to pass to `func` Returns: @@ -834,6 +838,10 @@ class DatabasePool: try: if db_autocommit: self.engine.attempt_to_set_autocommit(conn, True) + if isolation_level is not None: + self.engine.attempt_to_set_isolation_level( + conn, isolation_level + ) db_conn = LoggingDatabaseConnection( conn, self.engine, "runWithConnection" @@ -842,6 +850,8 @@ class DatabasePool: finally: if db_autocommit: self.engine.attempt_to_set_autocommit(conn, False) + if isolation_level: + self.engine.attempt_to_set_isolation_level(conn, None) return await make_deferred_yieldable( self._db_pool.runWithConnection(inner_func, *args, **kwargs) diff --git a/synapse/storage/engines/_base.py b/synapse/storage/engines/_base.py index 20cd63c330..143cd98ca2 100644 --- a/synapse/storage/engines/_base.py +++ b/synapse/storage/engines/_base.py @@ -12,11 +12,18 @@ # See the License for the specific language governing permissions and # limitations under the License. import abc -from typing import Generic, TypeVar +from enum import IntEnum +from typing import Generic, Optional, TypeVar from synapse.storage.types import Connection +class IsolationLevel(IntEnum): + READ_COMMITTED: int = 1 + REPEATABLE_READ: int = 2 + SERIALIZABLE: int = 3 + + class IncorrectDatabaseSetup(RuntimeError): pass @@ -109,3 +116,13 @@ class BaseDatabaseEngine(Generic[ConnectionType], metaclass=abc.ABCMeta): commit/rollback the connections. """ ... + + @abc.abstractmethod + def attempt_to_set_isolation_level( + self, conn: Connection, isolation_level: Optional[int] + ): + """Attempt to set the connections isolation level. + + Note: This has no effect on SQLite3, as transactions are SERIALIZABLE by default. + """ + ... diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py index b3d71f661c..808342fafb 100644 --- a/synapse/storage/engines/postgres.py +++ b/synapse/storage/engines/postgres.py @@ -13,8 +13,13 @@ # limitations under the License. import logging +from typing import Mapping, Optional -from synapse.storage.engines._base import BaseDatabaseEngine, IncorrectDatabaseSetup +from synapse.storage.engines._base import ( + BaseDatabaseEngine, + IncorrectDatabaseSetup, + IsolationLevel, +) from synapse.storage.types import Connection logger = logging.getLogger(__name__) @@ -34,6 +39,15 @@ class PostgresEngine(BaseDatabaseEngine): self.synchronous_commit = database_config.get("synchronous_commit", True) self._version = None # unknown as yet + self.isolation_level_map: Mapping[int, int] = { + IsolationLevel.READ_COMMITTED: self.module.extensions.ISOLATION_LEVEL_READ_COMMITTED, + IsolationLevel.REPEATABLE_READ: self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ, + IsolationLevel.SERIALIZABLE: self.module.extensions.ISOLATION_LEVEL_SERIALIZABLE, + } + self.default_isolation_level = ( + self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ + ) + @property def single_threaded(self) -> bool: return False @@ -104,9 +118,7 @@ class PostgresEngine(BaseDatabaseEngine): return sql.replace("?", "%s") def on_new_connection(self, db_conn): - db_conn.set_isolation_level( - self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ - ) + db_conn.set_isolation_level(self.default_isolation_level) # Set the bytea output to escape, vs the default of hex cursor = db_conn.cursor() @@ -175,3 +187,12 @@ class PostgresEngine(BaseDatabaseEngine): def attempt_to_set_autocommit(self, conn: Connection, autocommit: bool): return conn.set_session(autocommit=autocommit) # type: ignore + + def attempt_to_set_isolation_level( + self, conn: Connection, isolation_level: Optional[int] + ): + if isolation_level is None: + isolation_level = self.default_isolation_level + else: + isolation_level = self.isolation_level_map[isolation_level] + return conn.set_isolation_level(isolation_level) # type: ignore diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py index 70d17d4f2c..6c19e55999 100644 --- a/synapse/storage/engines/sqlite.py +++ b/synapse/storage/engines/sqlite.py @@ -15,6 +15,7 @@ import platform import struct import threading import typing +from typing import Optional from synapse.storage.engines import BaseDatabaseEngine from synapse.storage.types import Connection @@ -122,6 +123,12 @@ class Sqlite3Engine(BaseDatabaseEngine["sqlite3.Connection"]): # set the connection to autocommit mode. pass + def attempt_to_set_isolation_level( + self, conn: Connection, isolation_level: Optional[int] + ): + # All transactions are SERIALIZABLE by default in sqllite + pass + # Following functions taken from: https://github.com/coleifer/peewee |