129 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2015, 2016 OpenMarket Ltd
 | 
						|
#
 | 
						|
# Licensed under the Apache License, Version 2.0 (the "License");
 | 
						|
# you may not use this file except in compliance with the License.
 | 
						|
# You may obtain a copy of the License at
 | 
						|
#
 | 
						|
#     http://www.apache.org/licenses/LICENSE-2.0
 | 
						|
#
 | 
						|
# Unless required by applicable law or agreed to in writing, software
 | 
						|
# distributed under the License is distributed on an "AS IS" BASIS,
 | 
						|
# 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 abc
 | 
						|
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
 | 
						|
 | 
						|
 | 
						|
ConnectionType = TypeVar("ConnectionType", bound=Connection)
 | 
						|
 | 
						|
 | 
						|
class BaseDatabaseEngine(Generic[ConnectionType], metaclass=abc.ABCMeta):
 | 
						|
    def __init__(self, module, database_config: dict):
 | 
						|
        self.module = module
 | 
						|
 | 
						|
    @property
 | 
						|
    @abc.abstractmethod
 | 
						|
    def single_threaded(self) -> bool:
 | 
						|
        ...
 | 
						|
 | 
						|
    @property
 | 
						|
    @abc.abstractmethod
 | 
						|
    def can_native_upsert(self) -> bool:
 | 
						|
        """
 | 
						|
        Do we support native UPSERTs?
 | 
						|
        """
 | 
						|
        ...
 | 
						|
 | 
						|
    @property
 | 
						|
    @abc.abstractmethod
 | 
						|
    def supports_using_any_list(self) -> bool:
 | 
						|
        """
 | 
						|
        Do we support using `a = ANY(?)` and passing a list
 | 
						|
        """
 | 
						|
        ...
 | 
						|
 | 
						|
    @property
 | 
						|
    @abc.abstractmethod
 | 
						|
    def supports_returning(self) -> bool:
 | 
						|
        """Do we support the `RETURNING` clause in insert/update/delete?"""
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def check_database(
 | 
						|
        self, db_conn: ConnectionType, allow_outdated_version: bool = False
 | 
						|
    ) -> None:
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def check_new_database(self, txn) -> None:
 | 
						|
        """Gets called when setting up a brand new database. This allows us to
 | 
						|
        apply stricter checks on new databases versus existing database.
 | 
						|
        """
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def convert_param_style(self, sql: str) -> str:
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def on_new_connection(self, db_conn: ConnectionType) -> None:
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def is_deadlock(self, error: Exception) -> bool:
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def is_connection_closed(self, conn: ConnectionType) -> bool:
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def lock_table(self, txn, table: str) -> None:
 | 
						|
        ...
 | 
						|
 | 
						|
    @property
 | 
						|
    @abc.abstractmethod
 | 
						|
    def server_version(self) -> str:
 | 
						|
        """Gets a string giving the server version. For example: '3.22.0'"""
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def in_transaction(self, conn: Connection) -> bool:
 | 
						|
        """Whether the connection is currently in a transaction."""
 | 
						|
        ...
 | 
						|
 | 
						|
    @abc.abstractmethod
 | 
						|
    def attempt_to_set_autocommit(self, conn: Connection, autocommit: bool):
 | 
						|
        """Attempt to set the connections autocommit mode.
 | 
						|
 | 
						|
        When True queries are run outside of transactions.
 | 
						|
 | 
						|
        Note: This has no effect on SQLite3, so callers still need to
 | 
						|
        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.
 | 
						|
        """
 | 
						|
        ...
 |