delta/python-packages/sqlalchemy.git/lib/sqlalchemy/pool/base.py, branch review/mike_bayer/tutorial20 github.com: zzzeek/sqlalchemy.git generalize scoped_session proxying and apply to asyncio elements 2020-10-10T05:17:25+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-10-08T19:20:48+00:00 2665a0c4cb3e94e6545d0b9bbcbcc39ccffebaba Reworked the proxy creation used by scoped_session() to be based on fully copied code with augmented docstrings and moved it into langhelpers. asyncio session, engine, connection can now take advantage of it so that all non-async methods are availble. Overall implementation of most important accessors / methods on AsyncConnection, etc. , including awaitable versions of invalidate, execution_options, etc. In order to support an event dispatcher on the async classes while still allowing them to hold __slots__, make some adjustments to the event system to allow that to be present, at least rudimentally. Fixes: #5628 Change-Id: I5eb6929fc1e4fdac99e4b767dcfd49672d56e2b2 
Reworked the proxy creation used by scoped_session() to be
based on fully copied code with augmented docstrings and
moved it into langhelpers.  asyncio session, engine,
connection can now take
advantage of it so that all non-async methods are availble.

Overall implementation of most important accessors / methods
on AsyncConnection, etc. , including awaitable versions
of invalidate, execution_options, etc.

In order to support an event dispatcher on the async
classes while still allowing them to hold __slots__,
make some adjustments to the event system to allow
that to be present, at least rudimentally.

Fixes: #5628
Change-Id: I5eb6929fc1e4fdac99e4b767dcfd49672d56e2b2
Revert "Use monotonic time for pool age measurement" 2020-10-07T14:09:41+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-10-07T14:09:41+00:00 3ca8b453088ac6fb815e2f39c9a705b49bfb188c This reverts commit 0220b58917b5a979891b5765f6ac5095e0368489. I completely misread https://www.python.org/dev/peps/pep-0418/#rationale and the accuracy of monotonic() is *worse* on windows than time.time(), which is bizarre. Change-Id: I2d571e268a2051bea68736507773d3904403af9e 
This reverts commit 0220b58917b5a979891b5765f6ac5095e0368489.

I completely misread https://www.python.org/dev/peps/pep-0418/#rationale
and the accuracy of monotonic() is *worse* on windows than time.time(),
which is bizarre.

Change-Id: I2d571e268a2051bea68736507773d3904403af9e
Use monotonic time for pool age measurement 2020-10-07T13:14:13+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-10-07T12:42:48+00:00 0220b58917b5a979891b5765f6ac5095e0368489 The internal clock used by the :class:`_pool.Pool` object is now time.monotonic_time() under Python 3. Under Python 2, time.time() is still used, which is legacy. This clock is used to measure the age of a connection against its starttime, and used in comparisons against the pool_timeout setting as well as the last time the pool was marked as invalid to determine if the connection should be recycled. Previously, time.time() was used which was subject to inaccuracies as a result of system clock changes as well as poor time resolution on windows. Change-Id: I94f90044c1809508e26a5a00134981c2a00d0405 
The internal clock used by the :class:`_pool.Pool` object is now
time.monotonic_time() under Python 3.  Under Python 2, time.time() is still
used, which is legacy. This clock is used to measure the age of a
connection against its starttime, and used in comparisons against the
pool_timeout setting as well as the last time the pool was marked as
invalid to determine if the connection should be recycled. Previously,
time.time() was used which was subject to inaccuracies as a result of
system clock changes as well as poor time resolution on windows.

Change-Id: I94f90044c1809508e26a5a00134981c2a00d0405
Adapt event exec_once_mutex to asyncio 2020-09-14T12:04:09+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-09-14T12:04:09+00:00 4d17fe4063adef50c1d529993e0b047f503940e2 The pool makes use of a threading.Lock() for the "first_connect" event. if the pool is async make sure this is a greenlet-adapted asyncio lock. Fixes: #5581 Change-Id: If52415839c7ed82135465f1fe93b95d86c305820 
The pool makes use of a threading.Lock() for the
"first_connect" event.  if the pool is async make sure this
is a greenlet-adapted asyncio lock.

Fixes: #5581
Change-Id: If52415839c7ed82135465f1fe93b95d86c305820
Assert reset agent always set correctly and is active 2020-05-13T20:12:42+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-05-13T16:42:08+00:00 916e1fea25afcd07fa1d1d2f72043b372cd02223 Fixed fairly critical issue where the DBAPI connection could be returned to the connection pool while still in an un-rolled-back state. The reset agent responsible for rolling back the connection could be corrupted in the case that the transaction was "closed" without being rolled back or committed, which can occur in some scenarios when using ORM sessions and emitting .close() in a certain pattern involving savepoints. The fix ensures that the reset agent is always active. note that the reset agent will go away in 2.0 and the only real purpose of it is for logging of ROLLBACK. Apparently with the SQLite singleton engine in the test suite, there are some strucutral mismatches in the test fixtures where the reset agent is getting set differently than the transaction likely due to the same connection being shared in multiple context, though it's unclear. Fixes: #5326 Change-Id: If056870ea70a2d9a1749768988d5e023f3061b31 
Fixed fairly critical issue where the DBAPI connection could be returned to
the connection pool while still in an un-rolled-back state. The reset agent
responsible for rolling back the connection could be corrupted in the case
that the transaction was "closed" without being rolled back or committed,
which can occur in some scenarios when using ORM sessions and emitting
.close() in a certain pattern involving savepoints.   The fix ensures that
the reset agent is always active.

note that the reset agent will go away in 2.0 and the only real
purpose of it is for logging of ROLLBACK.   Apparently with the
SQLite singleton engine in the test suite, there are some strucutral
mismatches in the test fixtures where the reset agent is getting
set differently than the transaction likely due to the same connection
being shared in multiple context, though it's unclear.

Fixes: #5326
Change-Id: If056870ea70a2d9a1749768988d5e023f3061b31
Set up absolute references for create_engine and related 2020-04-14T20:39:42+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-04-14T20:39:42+00:00 447c0750e1f739c4db1d0d20de182c297dc86e36 includes more replacements for create_engine(), Connection, disambiguation of Result from future/baked Change-Id: Icb60a79ee7a6c45ea9056c211ffd1be110da3b5e 
includes more replacements for create_engine(), Connection,
disambiguation of Result from future/baked

Change-Id: Icb60a79ee7a6c45ea9056c211ffd1be110da3b5e
Run search and replace of symbolic module names 2020-04-14T17:15:21+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-04-14T17:15:21+00:00 cea03be855514d592b6671fa6dbc074a19a795fb Replaces a wide array of Sphinx-relative doc references with an abbreviated absolute form now supported by zzzeeksphinx. Change-Id: I94bffcc3f37885ffdde6238767224296339698a2 
Replaces a wide array of Sphinx-relative doc references
with an abbreviated absolute form now supported by
zzzeeksphinx.

Change-Id: I94bffcc3f37885ffdde6238767224296339698a2
Ensure all nested exception throws have a cause 2020-03-02T22:24:19+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-02-29T19:40:45+00:00 57dc36a01b2b334a996f73f6a78b3bfbe4d9f2ec Applied an explicit "cause" to most if not all internally raised exceptions that are raised from within an internal exception catch, to avoid misleading stacktraces that suggest an error within the handling of an exception. While it would be preferable to suppress the internally caught exception in the way that the ``__suppress_context__`` attribute would, there does not as yet seem to be a way to do this without suppressing an enclosing user constructed context, so for now it exposes the internally caught exception as the cause so that full information about the context of the error is maintained. Fixes: #4849 Change-Id: I55a86b29023675d9e5e49bc7edc5a2dc0bcd4751 
Applied an explicit "cause" to most if not all internally raised exceptions
that are raised from within an internal exception catch, to avoid
misleading stacktraces that suggest an error within the handling of an
exception.  While it would be preferable to suppress the internally caught
exception in the way that the ``__suppress_context__`` attribute would,
there does not as yet seem to be a way to do this without suppressing an
enclosing user constructed context, so for now it exposes the internally
caught exception as the cause so that full information about the context
of the error is maintained.

Fixes: #4849
Change-Id: I55a86b29023675d9e5e49bc7edc5a2dc0bcd4751
Don't call pre_ping for fresh connection 2020-02-26T17:04:11+00:00 Mike Bayer mike_mp@zzzcomputing.com 2019-03-05T20:37:00+00:00 f78db5e1f68d6b2fb6a7acc04036f682d9a22974 The pool "pre-ping" feature has been refined to not invoke for a DBAPI connection that was just opened in the same checkout operation. pre ping only applies to a DBAPI connection that's been checked into the pool and is being checked out again. Fixes: #4524 Change-Id: Ibe3dfb709dbdc24aa94e96513cfbea456c33b895 
The pool "pre-ping" feature has been refined to not invoke for a DBAPI
connection that was just opened in the same checkout operation.  pre ping
only applies to a DBAPI connection that's been checked into the pool
and is being checked out again.

Fixes: #4524
Change-Id: Ibe3dfb709dbdc24aa94e96513cfbea456c33b895
Do away with pool._refs 2020-02-01T18:12:57+00:00 Mike Bayer mike_mp@zzzcomputing.com 2020-02-01T17:27:09+00:00 c797056413230cc5c11bc458e5f7760063c2682e This collection was added only for the benefit of unit tests and is unnecessary for the pool to function. As SQLAlchemy 2.0 will be removing the automatic handling of connections that are garbage collection, remove this collection so that we ultimately don't need a weakref handler to do anything within the pool. The handler will do nothing other than emit a warning that a connection was dereferenced without being explicitly returned to the pool, invalidated, or detached. Change-Id: I4ca196270d5714efbac44dbf6f034e8c7f0af58a 
This collection was added only for the benefit of unit tests
and is unnecessary for the pool to function.  As SQLAlchemy 2.0
will be removing the automatic handling of connections that are
garbage collection, remove this collection so that we ultimately
don't need a weakref handler to do anything within the pool.
The handler will do nothing other than emit a warning that
a connection was dereferenced without being explicitly returned
to the pool, invalidated, or detached.

Change-Id: I4ca196270d5714efbac44dbf6f034e8c7f0af58a