From: Mike Bayer Date: Thu, 28 Dec 2006 08:30:43 +0000 (+0000) Subject: - speed enhancements to ORM object instantiation, eager loading of rows X-Git-Tag: rel_0_3_4~66 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34b3bbd034485737114814f4ba599f9778f44c59;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git - speed enhancements to ORM object instantiation, eager loading of rows --- diff --git a/CHANGES b/CHANGES index bbb69fcd45..57a763b99a 100644 --- a/CHANGES +++ b/CHANGES @@ -7,6 +7,7 @@ thanks to jason (at) ncsmags.com [ticket:402] is constructed with individual calls to append_column(); this fixes an ORM bug whereby nested select statements were not getting correlated with the main select generated by the Query object. +- speed enhancements to ORM object instantiation, eager loading of rows 0.3.3 - string-based FROM clauses fixed, i.e. select(..., from_obj=["sometext"]) diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py index 17f9096130..2b51621dbe 100644 --- a/lib/sqlalchemy/orm/attributes.py +++ b/lib/sqlalchemy/orm/attributes.py @@ -758,11 +758,9 @@ class AttributeManager(object): #print self, "register attribute", key, "for class", class_ if not hasattr(class_, '_state'): def _get_state(self): - try: - return self.__sa_attr_state - except AttributeError: - self.__sa_attr_state = {} - return self.__sa_attr_state + if not hasattr(self, '_sa_attr_state'): + self._sa_attr_state = {} + return self._sa_attr_state class_._state = property(_get_state) typecallable = kwargs.pop('typecallable', None) diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py index 0f607ebeec..74784d3846 100644 --- a/lib/sqlalchemy/orm/interfaces.py +++ b/lib/sqlalchemy/orm/interfaces.py @@ -61,11 +61,18 @@ class StrategizedProperty(MapperProperty): There is a single default strategy selected, and alternate strategies can be selected at selection time through the usage of StrategizedOption objects.""" def _get_context_strategy(self, context): - return self._get_strategy(context.attributes.get((LoaderStrategy, self), self.strategy.__class__)) + try: + return context.attributes[id(self)] + except KeyError: + # cache the located strategy per StrategizedProperty in the given context for faster re-lookup + ctx_strategy = self._get_strategy(context.attributes.get((LoaderStrategy, self), self.strategy.__class__)) + context.attributes[id(self)] = ctx_strategy + return ctx_strategy def _get_strategy(self, cls): try: return self._all_strategies[cls] except KeyError: + # cache the located strategy per class for faster re-lookup strategy = cls(self) strategy.init() strategy.is_default = False diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py index 46ef5f60fa..7de5135083 100644 --- a/lib/sqlalchemy/orm/mapper.py +++ b/lib/sqlalchemy/orm/mapper.py @@ -1352,25 +1352,44 @@ class MapperExtension(object): class _ExtensionCarrier(MapperExtension): def __init__(self): self.__elements = [] - self.__callables = {} def insert(self, extension): """insert a MapperExtension at the beginning of this ExtensionCarrier's list.""" self.__elements.insert(0, extension) def append(self, extension): """append a MapperExtension at the end of this ExtensionCarrier's list.""" self.__elements.append(extension) - def __getattribute__(self, key): - if key in MapperExtension.__dict__: - try: - return self.__callables[key] - except KeyError: - return self.__callables.setdefault(key, lambda *args, **kwargs:self._do(key, *args, **kwargs)) - else: - return super(_ExtensionCarrier, self).__getattribute__(key) + def get_session(self, *args, **kwargs): + return self._do('get_session', *args, **kwargs) + def load(self, *args, **kwargs): + return self._do('load', *args, **kwargs) + def get(self, *args, **kwargs): + return self._do('get', *args, **kwargs) + def get_by(self, *args, **kwargs): + return self._do('get_by', *args, **kwargs) + def select_by(self, *args, **kwargs): + return self._do('select_by', *args, **kwargs) + def select(self, *args, **kwargs): + return self._do('select', *args, **kwargs) + def create_instance(self, *args, **kwargs): + return self._do('create_instance', *args, **kwargs) + def append_result(self, *args, **kwargs): + return self._do('append_result', *args, **kwargs) + def populate_instance(self, *args, **kwargs): + return self._do('populate_instance', *args, **kwargs) + def before_insert(self, *args, **kwargs): + return self._do('before_insert', *args, **kwargs) + def before_update(self, *args, **kwargs): + return self._do('before_update', *args, **kwargs) + def after_update(self, *args, **kwargs): + return self._do('after_update', *args, **kwargs) + def after_insert(self, *args, **kwargs): + return self._do('after_insert', *args, **kwargs) + def before_delete(self, *args, **kwargs): + return self._do('before_delete', *args, **kwargs) + def after_delete(self, *args, **kwargs): + return self._do('after_delete', *args, **kwargs) def _do(self, funcname, *args, **kwargs): for elem in self.__elements: - if elem is self: - raise exceptions.AssertionError("ExtensionCarrier set to itself") ret = getattr(elem, funcname)(*args, **kwargs) if ret is not EXT_PASS: return ret diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py index 78a873c704..af56bda80c 100644 --- a/lib/sqlalchemy/orm/strategies.py +++ b/lib/sqlalchemy/orm/strategies.py @@ -463,31 +463,55 @@ class EagerLoader(AbstractRelationLoader): for value in self.mapper.props.values(): value.setup(context, eagertable=clauses.eagertarget, parentclauses=clauses, parentmapper=self.mapper) + def _create_row_processor(self, selectcontext, row): + """create a 'row processing' function that will apply eager aliasing to the row. + + also check that an identity key can be retrieved from the row, else return None.""" + # check for a user-defined decorator in the SelectContext (which was set up by the contains_eager() option) + if selectcontext.attributes.has_key((EagerLoader, self.parent_property)): + # custom row decoration function, placed in the selectcontext by the + # contains_eager() mapper option + decorator = selectcontext.attributes[(EagerLoader, self.parent_property)] + if decorator is None: + decorator = lambda row: row + else: + try: + # decorate the row according to the stored AliasedClauses for this eager load + clauses = self.clauses_by_lead_mapper[selectcontext.mapper] + decorator = clauses._row_decorator + except KeyError: + # no stored AliasedClauses: eager loading was not set up in the query and + # AliasedClauses never got initialized + return None + + try: + decorated_row = decorator(row) + # check for identity key + identity_key = self.mapper.identity_key_from_row(decorated_row) + # and its good + return decorator + except KeyError: + # no identity key - dont return a row processor, will cause a degrade to lazy + return None + def process_row(self, selectcontext, instance, row, identitykey, isnew): """receive a row. tell our mapper to look for a new object instance in the row, and attach it to a list on the parent instance.""" - if self in selectcontext.recursion_stack: return try: - # decorate the row according to the stored AliasedClauses for this eager load, - # or look for a user-defined decorator in the SelectContext (which was set up by the contains_eager() option) - if selectcontext.attributes.has_key((EagerLoader, self.parent_property)): - # custom row decoration function, placed in the selectcontext by the - # contains_eager() mapper option - decorator = selectcontext.attributes[(EagerLoader, self.parent_property)] - if decorator is None: - decorated_row = row - else: - decorated_row = decorator(row) - else: - clauses = self.clauses_by_lead_mapper[selectcontext.mapper] - decorated_row = clauses._decorate_row(row) - # check for identity key - identity_key = self.mapper.identity_key_from_row(decorated_row) + # check for row processor + row_processor = selectcontext.attributes[id(self)] except KeyError: - # else degrade to a lazy loader + # create a row processor function and cache it in the context + row_processor = self._create_row_processor(selectcontext, row) + selectcontext.attributes[id(self)] = row_processor + + if row_processor is not None: + decorated_row = row_processor(row) + else: + # row_processor was None: degrade to a lazy loader if self._should_log_debug: self.logger.debug("degrade to lazy loader on %s" % mapperutil.attribute_str(instance, self.key)) self.parent_property._get_strategy(LazyLoader).process_row(selectcontext, instance, row, identitykey, isnew)