diff options
Diffstat (limited to 'lib/sqlalchemy/orm/base.py')
| -rw-r--r-- | lib/sqlalchemy/orm/base.py | 221 |
1 files changed, 125 insertions, 96 deletions
diff --git a/lib/sqlalchemy/orm/base.py b/lib/sqlalchemy/orm/base.py index f6e7143fd..a85f59f37 100644 --- a/lib/sqlalchemy/orm/base.py +++ b/lib/sqlalchemy/orm/base.py @@ -14,103 +14,128 @@ from ..sql import expression from . import exc import operator -PASSIVE_NO_RESULT = util.symbol('PASSIVE_NO_RESULT', - """Symbol returned by a loader callable or other attribute/history -retrieval operation when a value could not be determined, based -on loader callable flags. -""" - ) - -ATTR_WAS_SET = util.symbol('ATTR_WAS_SET', - """Symbol returned by a loader callable to indicate the -retrieved value, or values, were assigned to their attributes -on the target object. -""") - -ATTR_EMPTY = util.symbol('ATTR_EMPTY', - """Symbol used internally to indicate an attribute had no callable. -""") +PASSIVE_NO_RESULT = util.symbol( + 'PASSIVE_NO_RESULT', + """Symbol returned by a loader callable or other attribute/history + retrieval operation when a value could not be determined, based + on loader callable flags. + """ +) -NO_VALUE = util.symbol('NO_VALUE', - """Symbol which may be placed as the 'previous' value of an attribute, -indicating no value was loaded for an attribute when it was modified, -and flags indicated we were not to load it. -""" - ) +ATTR_WAS_SET = util.symbol( + 'ATTR_WAS_SET', + """Symbol returned by a loader callable to indicate the + retrieved value, or values, were assigned to their attributes + on the target object. + """ +) + +ATTR_EMPTY = util.symbol( + 'ATTR_EMPTY', + """Symbol used internally to indicate an attribute had no callable.""" +) + +NO_VALUE = util.symbol( + 'NO_VALUE', + """Symbol which may be placed as the 'previous' value of an attribute, + indicating no value was loaded for an attribute when it was modified, + and flags indicated we were not to load it. + """ +) -NEVER_SET = util.symbol('NEVER_SET', - """Symbol which may be placed as the 'previous' value of an attribute -indicating that the attribute had not been assigned to previously. -""" - ) - -NO_CHANGE = util.symbol("NO_CHANGE", - """No callables or SQL should be emitted on attribute access -and no state should change""", canonical=0 - ) - -CALLABLES_OK = util.symbol("CALLABLES_OK", - """Loader callables can be fired off if a value -is not present.""", canonical=1 - ) - -SQL_OK = util.symbol("SQL_OK", - """Loader callables can emit SQL at least on scalar value -attributes.""", canonical=2) - -RELATED_OBJECT_OK = util.symbol("RELATED_OBJECT_OK", - """callables can use SQL to load related objects as well -as scalar value attributes. -""", canonical=4 - ) - -INIT_OK = util.symbol("INIT_OK", - """Attributes should be initialized with a blank -value (None or an empty collection) upon get, if no other -value can be obtained. -""", canonical=8 - ) - -NON_PERSISTENT_OK = util.symbol("NON_PERSISTENT_OK", - """callables can be emitted if the parent is not persistent.""", - canonical=16 - ) - -LOAD_AGAINST_COMMITTED = util.symbol("LOAD_AGAINST_COMMITTED", - """callables should use committed values as primary/foreign keys during a load -""", canonical=32 - ) - -NO_AUTOFLUSH = util.symbol("NO_AUTOFLUSH", - """loader callables should disable autoflush. -""", canonical=64) +NEVER_SET = util.symbol( + 'NEVER_SET', + """Symbol which may be placed as the 'previous' value of an attribute + indicating that the attribute had not been assigned to previously. + """ +) + +NO_CHANGE = util.symbol( + "NO_CHANGE", + """No callables or SQL should be emitted on attribute access + and no state should change + """, canonical=0 +) + +CALLABLES_OK = util.symbol( + "CALLABLES_OK", + """Loader callables can be fired off if a value + is not present. + """, canonical=1 +) + +SQL_OK = util.symbol( + "SQL_OK", + """Loader callables can emit SQL at least on scalar value attributes.""", + canonical=2 +) + +RELATED_OBJECT_OK = util.symbol( + "RELATED_OBJECT_OK", + """Callables can use SQL to load related objects as well + as scalar value attributes. + """, canonical=4 +) + +INIT_OK = util.symbol( + "INIT_OK", + """Attributes should be initialized with a blank + value (None or an empty collection) upon get, if no other + value can be obtained. + """, canonical=8 +) + +NON_PERSISTENT_OK = util.symbol( + "NON_PERSISTENT_OK", + """Callables can be emitted if the parent is not persistent.""", + canonical=16 +) + +LOAD_AGAINST_COMMITTED = util.symbol( + "LOAD_AGAINST_COMMITTED", + """Callables should use committed values as primary/foreign keys during a + load. + """, canonical=32 +) + +NO_AUTOFLUSH = util.symbol( + "NO_AUTOFLUSH", + """Loader callables should disable autoflush.""", + canonical=64 +) # pre-packaged sets of flags used as inputs -PASSIVE_OFF = util.symbol("PASSIVE_OFF", - "Callables can be emitted in all cases.", - canonical=(RELATED_OBJECT_OK | NON_PERSISTENT_OK | - INIT_OK | CALLABLES_OK | SQL_OK) - ) -PASSIVE_RETURN_NEVER_SET = util.symbol("PASSIVE_RETURN_NEVER_SET", - """PASSIVE_OFF ^ INIT_OK""", - canonical=PASSIVE_OFF ^ INIT_OK - ) -PASSIVE_NO_INITIALIZE = util.symbol("PASSIVE_NO_INITIALIZE", - "PASSIVE_RETURN_NEVER_SET ^ CALLABLES_OK", - canonical=PASSIVE_RETURN_NEVER_SET ^ CALLABLES_OK - ) -PASSIVE_NO_FETCH = util.symbol("PASSIVE_NO_FETCH", - "PASSIVE_OFF ^ SQL_OK", - canonical=PASSIVE_OFF ^ SQL_OK - ) -PASSIVE_NO_FETCH_RELATED = util.symbol("PASSIVE_NO_FETCH_RELATED", - "PASSIVE_OFF ^ RELATED_OBJECT_OK", - canonical=PASSIVE_OFF ^ RELATED_OBJECT_OK - ) -PASSIVE_ONLY_PERSISTENT = util.symbol("PASSIVE_ONLY_PERSISTENT", - "PASSIVE_OFF ^ NON_PERSISTENT_OK", - canonical=PASSIVE_OFF ^ NON_PERSISTENT_OK - ) +PASSIVE_OFF = util.symbol( + "PASSIVE_OFF", + "Callables can be emitted in all cases.", + canonical=(RELATED_OBJECT_OK | NON_PERSISTENT_OK | + INIT_OK | CALLABLES_OK | SQL_OK) +) +PASSIVE_RETURN_NEVER_SET = util.symbol( + "PASSIVE_RETURN_NEVER_SET", + """PASSIVE_OFF ^ INIT_OK""", + canonical=PASSIVE_OFF ^ INIT_OK +) +PASSIVE_NO_INITIALIZE = util.symbol( + "PASSIVE_NO_INITIALIZE", + "PASSIVE_RETURN_NEVER_SET ^ CALLABLES_OK", + canonical=PASSIVE_RETURN_NEVER_SET ^ CALLABLES_OK +) +PASSIVE_NO_FETCH = util.symbol( + "PASSIVE_NO_FETCH", + "PASSIVE_OFF ^ SQL_OK", + canonical=PASSIVE_OFF ^ SQL_OK +) +PASSIVE_NO_FETCH_RELATED = util.symbol( + "PASSIVE_NO_FETCH_RELATED", + "PASSIVE_OFF ^ RELATED_OBJECT_OK", + canonical=PASSIVE_OFF ^ RELATED_OBJECT_OK +) +PASSIVE_ONLY_PERSISTENT = util.symbol( + "PASSIVE_ONLY_PERSISTENT", + "PASSIVE_OFF ^ NON_PERSISTENT_OK", + canonical=PASSIVE_OFF ^ NON_PERSISTENT_OK +) DEFAULT_MANAGER_ATTR = '_sa_class_manager' DEFAULT_STATE_ATTR = '_sa_instance_state' @@ -194,7 +219,9 @@ def state_str(state): def state_class_str(state): - """Return a string describing an instance's class via its InstanceState.""" + """Return a string describing an instance's class via its + InstanceState. + """ if state is None: return "None" @@ -275,7 +302,8 @@ def _class_to_mapper(class_or_mapper): def _mapper_or_none(entity): """Return the :class:`.Mapper` for the given class or None if the - class is not mapped.""" + class is not mapped. + """ insp = inspection.inspect(entity, False) if insp is not None: @@ -286,7 +314,8 @@ def _mapper_or_none(entity): def _is_mapped_class(entity): """Return True if the given object is a mapped class, - :class:`.Mapper`, or :class:`.AliasedClass`.""" + :class:`.Mapper`, or :class:`.AliasedClass`. + """ insp = inspection.inspect(entity, False) return insp is not None and \ |