diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sqlalchemy/engine/__init__.py | 6 | ||||
| -rw-r--r-- | lib/sqlalchemy/engine/strategies.py | 3 | ||||
| -rw-r--r-- | lib/sqlalchemy/pool.py | 55 |
3 files changed, 56 insertions, 8 deletions
diff --git a/lib/sqlalchemy/engine/__init__.py b/lib/sqlalchemy/engine/__init__.py index 4fac3e532..23b4b0b3b 100644 --- a/lib/sqlalchemy/engine/__init__.py +++ b/lib/sqlalchemy/engine/__init__.py @@ -306,6 +306,12 @@ def create_engine(*args, **kwargs): this is configurable with the MySQLDB connection itself and the server configuration as well). + :param pool_reset_on_return='rollback': set the "reset on return" + behavior of the pool, which is whether ``rollback()``, + ``commit()``, or nothing is called upon connections + being returned to the pool. See the docstring for + ``reset_on_return`` at :class:`.Pool`. (new as of 0.7.6) + :param pool_timeout=30: number of seconds to wait before giving up on getting a connection from the pool. This is only used with :class:`~sqlalchemy.pool.QueuePool`. diff --git a/lib/sqlalchemy/engine/strategies.py b/lib/sqlalchemy/engine/strategies.py index 7b2da68c4..e3a6c5026 100644 --- a/lib/sqlalchemy/engine/strategies.py +++ b/lib/sqlalchemy/engine/strategies.py @@ -108,7 +108,8 @@ class DefaultEngineStrategy(EngineStrategy): 'timeout': 'pool_timeout', 'recycle': 'pool_recycle', 'events':'pool_events', - 'use_threadlocal':'pool_threadlocal'} + 'use_threadlocal':'pool_threadlocal', + 'reset_on_return':'pool_reset_on_return'} for k in util.get_cls_kwargs(poolclass): tk = translate.get(k, k) if tk in kwargs: diff --git a/lib/sqlalchemy/pool.py b/lib/sqlalchemy/pool.py index a615e8c60..cd935d4ae 100644 --- a/lib/sqlalchemy/pool.py +++ b/lib/sqlalchemy/pool.py @@ -57,6 +57,10 @@ def clear_managers(): manager.close() proxies.clear() +reset_rollback = util.symbol('reset_rollback') +reset_commit = util.symbol('reset_commit') +reset_none = util.symbol('reset_none') + class Pool(log.Identified): """Abstract base class for connection pools.""" @@ -130,7 +134,16 @@ class Pool(log.Identified): self._creator = creator self._recycle = recycle self._use_threadlocal = use_threadlocal - self._reset_on_return = reset_on_return + if reset_on_return in ('rollback', True): + self._reset_on_return = reset_rollback + elif reset_on_return in (None, False): + self._reset_on_return = reset_none + elif reset_on_return == 'commit': + self._reset_on_return = reset_commit + else: + raise exc.ArgumentError("Invalid value for 'reset_on_return': %r" + % reset_on_return) + self.echo = echo if _dispatch: self.dispatch._update(_dispatch, only_propagate=False) @@ -330,8 +343,10 @@ def _finalize_fairy(connection, connection_record, pool, ref, echo): if connection is not None: try: - if pool._reset_on_return: + if pool._reset_on_return is reset_rollback: connection.rollback() + elif pool._reset_on_return is reset_commit: + connection.commit() # Immediately close detached instances if connection_record is None: connection.close() @@ -624,11 +639,37 @@ class QueuePool(Pool): :meth:`unique_connection` method is provided to bypass the threadlocal behavior installed into :meth:`connect`. - :param reset_on_return: If true, reset the database state of - connections returned to the pool. This is typically a - ROLLBACK to release locks and transaction resources. - Disable at your own peril. Defaults to True. - + :param reset_on_return: Determine steps to take on + connections as they are returned to the pool. + As of SQLAlchemy 0.7.6, reset_on_return can have any + of these values: + + * 'rollback' - call rollback() on the connection, + to release locks and transaction resources. + This is the default value. The vast majority + of use cases should leave this value set. + * True - same as 'rollback', this is here for + backwards compatibility. + * 'commit' - call commit() on the connection, + to release locks and transaction resources. + A commit here may be desirable for databases that + cache query plans if a commit is emitted, + such as Microsoft SQL Server. However, this + value is more dangerous than 'rollback' because + any data changes present on the transaction + are committed unconditionally. + * None - don't do anything on the connection. + This setting should only be made on a database + that has no transaction support at all, + namely MySQL MyISAM. By not doing anything, + performance can be improved. This + setting should **never be selected** for a + database that supports transactions, + as it will lead to deadlocks and stale + state. + * False - same as None, this is here for + backwards compatibility. + :param listeners: A list of :class:`~sqlalchemy.interfaces.PoolListener`-like objects or dictionaries of callables that receive events when DB-API |