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# This file is part of Buildbot. Buildbot is free software: you can
# redistribute it and/or modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation, version 2.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 51
# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Copyright Buildbot Team Members
class DBConnectorComponent(object):
# A fixed component of the DBConnector, handling one particular aspect of
# the database. Instances of subclasses are assigned to attributes of the
# DBConnector object, so that they are available at e.g.,
# C{master.db.model} or C{master.db.changes}. This parent class takes care
# of the necessary backlinks and other housekeeping.
connector = None
def __init__(self, connector):
self.db = connector
# set up caches
for method in dir(self.__class__):
o = getattr(self, method)
if isinstance(o, CachedMethod):
setattr(self, method, o.get_cached_method(self))
_is_check_length_necessary = None
def check_length(self, col, value):
# for use by subclasses to check that 'value' will fit in 'col', where
# 'col' is a table column from the model.
# ignore this check for database engines that either provide this error
# themselves (postgres) or that do not enforce maximum-length
# restrictions (sqlite)
if not self._is_check_length_necessary:
if self.db.pool.engine.dialect.name == 'mysql':
self._is_check_length_necessary = True
else:
# not necessary, so just stub out the method
self.check_length = lambda col, value : None
return
assert col.type.length, "column %s does not have a length" % (col,)
if value and len(value) > col.type.length:
raise RuntimeError(
"value for column %s is greater than max of %d characters: %s"
% (col, col.type.length, value))
class CachedMethod(object):
def __init__(self, cache_name, method):
self.cache_name = cache_name
self.method = method
def get_cached_method(self, component):
meth = self.method
meth_name = meth.__name__
cache = component.db.master.caches.get_cache(self.cache_name,
lambda key : meth(component, key))
def wrap(key, no_cache=0):
if no_cache:
return meth(component, key)
return cache.get(key)
wrap.__name__ = meth_name + " (wrapped)"
wrap.__module__ = meth.__module__
wrap.__doc__ = meth.__doc__
wrap.cache = cache
return wrap
def cached(cache_name):
return lambda method : CachedMethod(cache_name, method)
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