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Use decorators to replace a few more manual checks of self.keep_history.

This commit is contained in:
Jason Madden 2017-01-27 09:49:10 -06:00
parent b4e68abefe
commit d85c754025
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GPG Key ID: 349F84431A08B99E
6 changed files with 190 additions and 48 deletions
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55
relstorage/adapters/_util.py
View File

@ -15,6 +15,7 @@
from functools import partial
from functools import update_wrapper
from functools import wraps
from relstorage._compat import intern
@ -83,3 +84,57 @@ def query_property(base_name,
return Lazy(prop, base_name + '_query')
formatted_query_property = partial(query_property, formatted=True)
def noop_when_history_free(meth):
"""
Decorator for *meth* that causes it to do nothing when
``self.keep_history`` is False.
*meth* must have no return value (returns None) when it is
history free. When history is preserved it can return anything.
This requires a bit more memory to use the instance dict, but at
runtime it has minimal time overhead (after the first call).
"""
# Python 3.4 (via timeit)
# calling a trivial method ('def t(self, arg): return arg') takes 118ns
# calling a method that does 'if not self.keep_history: return; return arg'
# takes 142 ns
# calling a functools.partial bound to self wrapped around t
# takes 298ns
# calling a generic python function
# def wrap(self, *args, **kwargs):
# if not self.keep_history: return
# return self.t(*args, **kwargs)
# takes 429ns
# So a partial function set into the __dict__ is the fastest way to
# do this.
meth_name = meth.__name__
@wraps(meth)
def no_op(*_args, **_kwargs):
return
@wraps(meth)
def swizzler(self, *args, **kwargs):
if not self.keep_history:
setattr(self, meth_name, no_op)
else:
# NOTE: This creates a reference cycle
bound = partial(meth, self)
update_wrapper(bound, meth)
if not hasattr(bound, '__wrapped__'):
bound.__wrapped__ = meth
setattr(self, meth_name, bound)
return getattr(self, meth_name)(*args, **kwargs)
if not hasattr(swizzler, '__wrapped__'):
# Py2: this was added in 3.2
swizzler.__wrapped__ = meth
no_op.__wrapped__ = meth
return swizzler

29
relstorage/adapters/mover.py
View File

@ -18,20 +18,13 @@ from perfmetrics import Metric
from relstorage.adapters.batch import RowBatcher
from relstorage.adapters.interfaces import IObjectMover
from relstorage.adapters._util import query_property as _query_property
from relstorage.adapters._util import noop_when_history_free
from relstorage.iter import fetchmany
from zope.interface import implementer
from hashlib import md5
from relstorage._compat import db_binary_to_bytes
def compute_md5sum(data):
if data is not None:
return md5(data).hexdigest()
else:
# George Bailey object
return None
metricmethod_sampled = Metric(method=True, rate=0.1)
@implementer(IObjectMover)
@ -48,10 +41,11 @@ class AbstractObjectMover(object):
self.version_detector = version_detector
self.make_batcher = batcher_factory
if self.keep_history:
self._compute_md5sum = compute_md5sum
else:
self._compute_md5sum = lambda arg: None
@noop_when_history_free
def _compute_md5sum(self, data):
if data is None:
return None
return md5(data).hexdigest()
_load_current_queries = (
"""
@ -415,17 +409,14 @@ class AbstractObjectMover(object):
ORDER BY zoid)
"""
@noop_when_history_free
@metricmethod_sampled
def update_current(self, cursor, tid): # pylint:disable=method-hidden
"""Update the current object pointers.
def update_current(self, cursor, tid):
"""
Update the current object pointers.
tid is the integer tid of the transaction being committed.
"""
if not self.keep_history:
# nothing needs to be updated
# Can elide this check in the future.
self.update_current = lambda cursor, tid: None
return
stmt = self._update_current_insert_query
cursor.execute(stmt, (tid,))

11
relstorage/adapters/mysql/mover.py
View File

@ -22,6 +22,7 @@ import os
from ..mover import AbstractObjectMover
from ..mover import metricmethod_sampled
from .._util import query_property
from .._util import noop_when_history_free
def to_prepared_queries(name, queries, extension=''):
@ -100,18 +101,14 @@ class MySQLObjectMover(AbstractObjectMover):
"""
cursor.execute(stmt, (tid,))
@noop_when_history_free
@metricmethod_sampled
def update_current(self, cursor, tid): # pylint:disable=method-hidden
"""Update the current object pointers.
"""
Update the current object pointers.
tid is the integer tid of the transaction being committed.
"""
if not self.keep_history:
# nothing needs to be updated
# Can elide this check in the future.
self.update_current = lambda cursor, tid: None
return
cursor.execute("""
REPLACE INTO current_object (zoid, tid)
SELECT zoid, tid FROM object_state

108
relstorage/adapters/tests/test_util.py Normal file
View File

@ -0,0 +1,108 @@
##############################################################################
#
# Copyright (c) 2017 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
import unittest
from relstorage.adapters._util import noop_when_history_free
from ..mover import metricmethod_sampled
class TestNoOp(unittest.TestCase):
def test_history_free(self):
class Thing(object):
keep_history = False
@noop_when_history_free
@metricmethod_sampled
def thing(self, arg1, arg2=False):
"Docs"
assert arg1
assert arg2
thing = Thing()
# Before calling it has a wrapper
thing_thing = thing.thing
self.assertTrue(hasattr(thing_thing, '__wrapped__'))
self.assertEqual(Thing.thing.__doc__, "Docs")
self.assertEqual(Thing.thing.__doc__, thing_thing.__doc__)
self.assertEqual(Thing.thing.__name__, 'thing')
self.assertEqual(Thing.thing.__name__, thing_thing.__name__)
# call with false args to be sure doesn't run
thing.thing(0) # one argument
thing.thing(0, arg2=0) # kwarg
# It still has a wrapper, but it's not the original
self.assertTrue(hasattr(thing.thing, '__wrapped__'))
self.assertIsNot(thing.thing, thing_thing)
self.assertEqual(Thing.thing.__doc__, thing.thing.__doc__)
self.assertEqual(Thing.thing.__name__, 'thing')
self.assertEqual(Thing.thing.__name__, thing.thing.__name__)
def test_keep_history(self):
class Thing(object):
keep_history = True
ran = False
@noop_when_history_free
def thing(self, arg1, arg2=False):
"Docs"
assert arg1
assert arg2
self.ran = True
return arg1
thing = Thing()
# Before calling it has a wrapper
thing_thing = thing.thing
self.assertTrue(hasattr(thing_thing, '__wrapped__'))
self.assertEqual(Thing.thing.__doc__, "Docs")
self.assertEqual(Thing.thing.__doc__, thing_thing.__doc__)
self.assertEqual(Thing.thing.__name__, 'thing')
self.assertEqual(Thing.thing.__name__, thing_thing.__name__)
# call with false args to be sure does run
self.assertRaises(AssertionError, thing.thing, 0) # one argument
thing.thing(1, arg2=1)
self.assertRaises(AssertionError, thing.thing, 1, arg2=0)
# It has access to self
self.assertTrue(thing.ran)
# It returns a value...
self.assertIs(self, thing.thing(self, 1))
# ...even the first time its called
self.assertIs(self, Thing().thing(self, 1))
# It still has a wrapper, but it's not the original
self.assertTrue(hasattr(thing.thing, '__wrapped__'))
self.assertIsNot(thing.thing, thing_thing)
self.assertEqual(Thing.thing.__doc__, thing.thing.__doc__)
self.assertEqual(Thing.thing.__name__, 'thing')
self.assertEqual(Thing.thing.__name__, thing.thing.__name__)
def test_suite():
suite = unittest.TestSuite()
suite.addTest(unittest.makeSuite(TestNoOp))
return suite
if __name__ == '__main__':
unittest.main(defaultTest='test_suite')

34
relstorage/adapters/txncontrol.py
View File

@ -22,7 +22,8 @@ import abc
from zope.interface import implementer
from .interfaces import ITransactionControl
from ._util import query_property
from ._util import noop_when_history_free
@six.add_metaclass(abc.ABCMeta)
class AbstractTransactionControl(object):
@ -70,23 +71,19 @@ class GenericTransactionControl(AbstractTransactionControl):
and history-preserving storages that share a common syntax.
"""
# XXX: Use the query_property for this
_GET_TID_HP = "SELECT MAX(tid) FROM transaction"
_GET_TID_HF = "SELECT MAX(tid) FROM object_state"
_get_tid_queries = (
"SELECT MAX(tid) FROM transaction",
"SELECT MAX(tid) FROM object_state"
)
_get_tid_query = query_property('_get_tid')
def __init__(self, keep_history, Binary): # noqa
self.keep_history = keep_history
self.Binary = Binary
if keep_history:
self.add_transaction = self._add_transaction_preserve
self._get_tid_stmt = self._GET_TID_HP
else:
self.add_transaction = self._add_transaction_free
self._get_tid_stmt = self._GET_TID_HF
def get_tid(self, cursor):
cursor.execute(self._get_tid_stmt)
cursor.execute(self._get_tid_query)
row = cursor.fetchone()
if not row:
# nothing has been stored yet
@ -95,14 +92,9 @@ class GenericTransactionControl(AbstractTransactionControl):
tid = row[0]
return tid if tid is not None else 0
def _add_transaction_free(self, cursor, tid, username, description, extension,
packed=False):
# pylint:disable=unused-argument
return
def _add_transaction_preserve(self, cursor, tid, username, description, extension,
packed=False):
@noop_when_history_free
def add_transaction(self, cursor, tid, username, description, extension,
packed=False):
stmt = """
INSERT INTO transaction
(tid, packed, username, description, extension)
@ -112,5 +104,3 @@ class GenericTransactionControl(AbstractTransactionControl):
cursor.execute(stmt, (
tid, packed, binary(username),
binary(description), binary(extension)))
add_transaction = lambda *args: None # dynamically replaced

1
relstorage/tests/alltests.py
View File

@ -30,6 +30,7 @@ def make_suite():
'relstorage.adapters.tests.test_batch',
'relstorage.adapters.tests.test_connmanager',
'relstorage.adapters.tests.test_replica',
'relstorage.adapters.tests.test_util',
'relstorage.cache.tests.test_cache',
'relstorage.cache.tests.test_cache_stats',
'relstorage.tests.test_autotemp',