156 lines
4.8 KiB
Python
156 lines
4.8 KiB
Python
# Copyright 2015, 2016 OpenMarket Ltd
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import abc
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from enum import IntEnum
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from typing import TYPE_CHECKING, Any, Generic, Mapping, Optional, TypeVar
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from synapse.storage.types import Connection, Cursor, DBAPI2Module
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if TYPE_CHECKING:
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from synapse.storage.database import LoggingDatabaseConnection
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class IsolationLevel(IntEnum):
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READ_COMMITTED: int = 1
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REPEATABLE_READ: int = 2
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SERIALIZABLE: int = 3
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class IncorrectDatabaseSetup(RuntimeError):
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pass
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ConnectionType = TypeVar("ConnectionType", bound=Connection)
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CursorType = TypeVar("CursorType", bound=Cursor)
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class BaseDatabaseEngine(Generic[ConnectionType, CursorType], metaclass=abc.ABCMeta):
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def __init__(self, module: DBAPI2Module, config: Mapping[str, Any]):
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self.module = module
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@property
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@abc.abstractmethod
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def single_threaded(self) -> bool:
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...
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@property
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@abc.abstractmethod
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def supports_using_any_list(self) -> bool:
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"""
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Do we support using `a = ANY(?)` and passing a list
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"""
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...
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@property
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@abc.abstractmethod
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def supports_returning(self) -> bool:
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"""Do we support the `RETURNING` clause in insert/update/delete?"""
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...
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@abc.abstractmethod
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def check_database(
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self, db_conn: ConnectionType, allow_outdated_version: bool = False
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) -> None:
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...
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@abc.abstractmethod
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def check_new_database(self, txn: CursorType) -> None:
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"""Gets called when setting up a brand new database. This allows us to
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apply stricter checks on new databases versus existing database.
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"""
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...
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@abc.abstractmethod
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def convert_param_style(self, sql: str) -> str:
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...
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# This method would ideally take a plain ConnectionType, but it seems that
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# the Sqlite engine expects to use LoggingDatabaseConnection.cursor
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# instead of sqlite3.Connection.cursor: only the former takes a txn_name.
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@abc.abstractmethod
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def on_new_connection(self, db_conn: "LoggingDatabaseConnection") -> None:
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...
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@abc.abstractmethod
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def is_deadlock(self, error: Exception) -> bool:
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...
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@abc.abstractmethod
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def is_connection_closed(self, conn: ConnectionType) -> bool:
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...
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@abc.abstractmethod
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def lock_table(self, txn: Cursor, table: str) -> None:
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...
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@property
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@abc.abstractmethod
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def server_version(self) -> str:
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"""Gets a string giving the server version. For example: '3.22.0'"""
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...
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@property
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@abc.abstractmethod
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def row_id_name(self) -> str:
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"""Gets the literal name representing a row id for this engine."""
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...
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@abc.abstractmethod
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def in_transaction(self, conn: ConnectionType) -> bool:
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"""Whether the connection is currently in a transaction."""
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...
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@abc.abstractmethod
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def attempt_to_set_autocommit(self, conn: ConnectionType, autocommit: bool) -> None:
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"""Attempt to set the connections autocommit mode.
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When True queries are run outside of transactions.
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Note: This has no effect on SQLite3, so callers still need to
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commit/rollback the connections.
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"""
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...
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@abc.abstractmethod
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def attempt_to_set_isolation_level(
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self, conn: ConnectionType, isolation_level: Optional[int]
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) -> None:
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"""Attempt to set the connections isolation level.
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Note: This has no effect on SQLite3, as transactions are SERIALIZABLE by default.
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"""
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...
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@staticmethod
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@abc.abstractmethod
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def executescript(cursor: CursorType, script: str) -> None:
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"""Execute a chunk of SQL containing multiple semicolon-delimited statements.
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This is not provided by DBAPI2, and so needs engine-specific support.
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Any ongoing transaction is committed before executing the script in its own
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transaction. The script transaction is left open and it is the responsibility of
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the caller to commit it.
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"""
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...
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@classmethod
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def execute_script_file(cls, cursor: CursorType, filepath: str) -> None:
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"""Execute a file containing multiple semicolon-delimited SQL statements.
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This is not provided by DBAPI2, and so needs engine-specific support.
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"""
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with open(filepath) as f:
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cls.executescript(cursor, f.read())
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