Coverage for master/buildbot/db/base : 100%

# 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)