def create_model(self, form):
"""
Create model from form.
:param form:
Form instance
"""
try:
model = self._manager.new_instance()
# TODO: We need a better way to create model instances and stay compatible with
# SQLAlchemy __init__() behavior
state = instance_state(model)
self._manager.dispatch.init(state, [], {})
form.populate_obj(model)
self.session.add(model)
self._on_model_change(form, model, True)
self.session.commit()
except Exception as ex:
if not self.handle_view_exception(ex):
flash(
gettext('Failed to create record. %(error)s',
error=str(ex)), 'error')
log.exception('Failed to create record.')
self.session.rollback()
return False
else:
self.after_model_change(form, model, True)
return model
def _deleted_by_this_query(host):
# This process of checking for an already deleted host relies
# on checking the session after it has been updated by the commit()
# function and marked the deleted hosts as expired. It is after this
# change that the host is called by a new query and, if deleted by a
# different process, triggers the ObjectDeletedError and is not emited.
return not instance_state(host).expired
def create_model(self, form):
"""
Create model from form.
:param form:
Form instance
"""
try:
model = self._manager.new_instance()
# TODO: We need a better way to create model instances and stay compatible with
# SQLAlchemy __init__() behavior
state = instance_state(model)
self._manager.dispatch.init(state, [], {})
form.populate_obj(model)
self.session.add(model)
self._on_model_change(form, model, True)
self.session.commit()
except Exception as ex:
if not self.handle_view_exception(ex):
flash(gettext('Failed to create record. %(error)s', error=str(ex)), 'error')
log.exception('Failed to create record.')
self.session.rollback()
return False
else:
self.after_model_change(form, model, True)
return model
def __init__(self, instance: object, *, copy: bool = False):
""" Make a lightweight snapshot of an instance.
Be sure to do it before flush(), because flush() will erase all in-memory changes.
Args:
instance: The instance to get the historical values for.
copy: Copy every mutable value.
Useful for embedded dictionaries, but it a bit more expensive, so disabled by default.
"""
# Model info
self.__model_info = sa_model_info(type(instance),
types=AttributeType.ALL)
# Remember the historical values
self.__state: InstanceState = instance_state(instance)
self.__historical = {
# Merging dictionaries is very cheap
**self.__state.dict, # current values
**self.__state.committed_state, # overwritten with DB values
}
# Make a deep copy to preserve embedded dictionaries
if copy:
self.__historical = deepcopy(self.__historical)
def tojson(self, request, instance, in_list=False, exclude=None,
exclude_related=None, safe=False, **kw):
instance = self.instance(instance)
obj = instance.obj
if instance_state(obj).detached:
with self.session(request) as session:
session.add(obj)
return self.tojson(request, instance, in_list=in_list,
exclude_related=exclude_related, safe=safe,
exclude=exclude, **kw)
info = self._fields
exclude = info.exclude(exclude, exclude_urls=True)
load_only = instance.fields
fields = {}
for field in self.fields().values():
name = field.name
if name in exclude or (load_only and name not in load_only):
continue
try:
data = self.get_instance_value(instance, name)
if isinstance(data, date):
if isinstance(data, datetime) and not data.tzinfo:
data = pytz.utc.localize(data)
data = data.isoformat()
elif isinstance(data, Enum):
data = data.name
elif is_rel_field(field):
if exclude_related:
continue
model = request.app.models.get(field.model)
if model:
data = self._related_model(request, model, data,
in_list)
else:
data = None
request.logger.error(
'Could not find model %s', field.model)
else: # Test Json
json.dumps(data)
except TypeError:
try:
data = str(data)
except Exception:
continue
except ObjectDeletedError:
raise ModelNotAvailable from None
except Exception:
if not safe:
request.logger.exception(
'Exception while converting attribute "%s" in model '
'%s to JSON', name, self)
continue
if data is not None:
if isinstance(data, list):
name = '%s[]' % name
fields[name] = data
return self.instance_urls(request, instance, fields)
def sa_modified_names(instance: object) -> Set[str]:
""" Get the set of modified attribute names
Note: you can only use it before flush(), because then all changes
are persisted and the information about them is lost.
"""
# `committed_state` is the dict of the original, unchanged, attribute names.
# `dict` contains current values, and when those are modified, old values go into `committed_state`.
# Therefore, `set(committed_state)` is what we want.
return set(instance_state(instance).committed_state)
def sa_set_committed_state(obj: object, **committed_values):
""" Put values into an SqlAlchemy instance as if they were committed to the DB """
# Give it some DB identity so that SA thinks it can load something
state: InstanceState = instance_state(obj)
state.key = object()
# Set every attribute in such a way that SA thinkg that's the way it looks in the DB
for k, v in committed_values.items():
set_committed_value(obj, k, v)
return obj
def _get_instance_states_with_unloaded(
session: Session, mapper: Mapper,
attr_name: str) -> Iterable[InstanceState]:
""" Iterate over instances in the `session` which have `attr_name` unloaded """
for instance in session:
if isinstance(instance, mapper.class_):
state: InstanceState = instance_state(instance)
# Only return instances that:
# 1. Are persistent in the DB (have a PK)
# 2. Have this attribute unloaded
if state.persistent and attr_name in state.unloaded:
yield state
def build_new_instance(self):
"""
Build new instance of a model. Useful to override the Flask-Admin behavior
when the model has a custom __init__ method.
"""
model = self._manager.new_instance()
# TODO: We need a better way to create model instances and stay compatible with
# SQLAlchemy __init__() behavior
state = instance_state(model)
self._manager.dispatch.init(state, [], {})
return model
def __init__(self, obj: object):
super().__init__(obj)
# Make a list of attributes the loading of which would lead to an unwanted DB query
state: InstanceState = instance_state(self._obj)
self._loaded = loaded_attribute_names(state)
self._safe_properties = get_all_safely_loadable_properties(type(obj))
# Now, because we're going to ignore some of the unloaded attributes, we'll need to set BaseModel.__fields_set__.
# However, we do not have any BaseModel here. Unfortunately.
# Therefore, we have to collect those unloaded fields and stash them somewhere.
# Where? Inside the intance itself: InstanceState.info is a perfect place
# Then, SALoadedModel will pick it up and set `__fields_set__` for us
self._excluded = state.info[SALoadedGetterDict] = set()
def sa_dependencies(instance: Union[SAInstanceT, Iterable[SAInstanceT]], map: PluckMap, _seen: set = None) -> List[PrimaryKey]:
""" Automatically collect PrimaryKey dependencies from SqlAlchemy instances
Usage: when you have an output from a query, use sa_dependencies() on it to get a list of dependencies
that you can provide to the MatroskaCache.put() function.
NOTE: it will only pick primary key dependencies! Other dependencies can only be provided manually!
Args:
instance: the instance to get dependencies from
map: inclusion map: {attribute: 1, relatiopnship: {key: 1, ...})
Use `1` to include an attribute, dict() to include a relationship, `0` to exclude something
NOTE: `map` must be valid!
"""
if _seen is None:
_seen = set()
# Lists
if isinstance(instance, (list, set, tuple)):
return list(itertools.chain.from_iterable(
sa_dependencies(item, map, _seen) for item in instance
))
# Instances
state: InstanceState = instance_state(instance)
relationships: Mapping[str, RelationshipProperty] = state.mapper.relationships
# Include self
ret = []
if instance not in _seen:
ret.append(PrimaryKey.from_instance(instance))
_seen.add(instance)
# If there's anything left to iterate, do it
if isinstance(map, dict):
for key, include in map.items():
# Skip excluded elements
if not include:
continue
# Skip non-relationships
if key not in relationships:
# TODO: implement dependencies on individual attributes?
continue
# Descend into the relationship
ret.extend(sa_dependencies(getattr(instance, key), include, _seen))
return ret
def get_history_proxy_for_instance(instance: SAInstanceT,
copy: bool = False) -> SAInstanceT:
""" Get a permanent InstanceHistoryProxy for an instance.
Every time this function is called on an instance, even after flush, the very same InstanceHistoryProxy will be returned.
Be careful with long-living instances: they will remember their original values the whole time.
"""
state: InstanceState = instance_state(instance)
# Create a new one
if InstanceHistoryProxy not in state.info:
state.info[InstanceHistoryProxy] = InstanceHistoryProxy(instance,
copy=copy)
# Done
return state.info[InstanceHistoryProxy]
def track_dirty(session, flush_context, instances):
"""
Record in session._all_changes the objects that have been modified before each flush
"""
for change, l in {"dirty": session.dirty,
"new": session.new,
"deleted": session.deleted}.items():
for obj in l:
# retrieve the dictionnary of changes for the given obj
attrs = session._all_changes.setdefault(id(obj), {})
# add the change of state to the list of state changes
attrs.setdefault("STATE_CHANGES", []).append(change)
attrs.setdefault("OBJECT", obj)
# save old value of attr if not already saved
# (if a value is changed multiple time, we keep only the first "old value")
for k, v in instance_state(obj).committed_state.items():
if k not in attrs:
attrs[k] = v
def track_dirty(session, flush_context, instances):
"""
Record in session._all_changes the objects that have been modified before each flush
"""
for change, l in {"dirty": session.dirty,
"new": session.new,
"deleted": session.deleted}.items():
for obj in l:
# retrieve the dictionnary of changes for the given obj
attrs = session._all_changes.setdefault(id(obj), {})
# add the change of state to the list of state changes
attrs.setdefault("STATE_CHANGES", []).append(change)
attrs.setdefault("OBJECT", obj)
# save old value of attr if not already saved
# (if a value is changed multiple time, we keep only the first "old value")
for k, v in instance_state(obj).committed_state.items():
if k not in attrs:
attrs[k] = v
def prevent_model_recursion(obj: SAModelT, marker_key: Hashable) -> Optional[SAModelT]:
""" Mark an instance as "being processed at the moment" and return it. In case of recursion, return None """
# Prepare a place to mark the instance as "being processed"
state: InstanceState = instance_state(obj)
marker_key = marker_key
# Is already being parsed? (recursion)
if marker_key in state.info:
yield None
return
# Mark the instance as "being processed at the moment"
state.info[marker_key] = True
# Parse it
try:
yield obj
finally:
# Unmark it
del state.info[marker_key]
def delete_by_id(host_id_list):
payload_tracker = get_payload_tracker(
account=current_identity.account_number,
payload_id=threadctx.request_id)
with PayloadTrackerContext(payload_tracker,
received_status_message="delete operation"):
query = _get_host_list_by_id_list(current_identity.account_number,
host_id_list)
hosts_to_delete = query.all()
if not hosts_to_delete:
return flask.abort(status.HTTP_404_NOT_FOUND)
with metrics.delete_host_processing_time.time():
query.delete(synchronize_session="fetch")
db.session.commit()
metrics.delete_host_count.inc(len(hosts_to_delete))
# This process of checking for an already deleted host relies
# on checking the session after it has been updated by the commit()
# function and marked the deleted hosts as expired. It is after this
# change that the host is called by a new query and, if deleted by a
# different process, triggers the ObjectDeletedError and is not emited.
for deleted_host in hosts_to_delete:
# Prevents ObjectDeletedError from being raised.
if instance_state(deleted_host).expired:
# Can’t log the Host ID. Accessing an attribute raises ObjectDeletedError.
logger.info("Host already deleted. Delete event not emitted.")
else:
with PayloadTrackerProcessingContext(
payload_tracker,
processing_status_message="deleted host"
) as payload_tracker_processing_ctx:
logger.debug("Deleted host: %s", deleted_host)
emit_event(events.delete(deleted_host))
payload_tracker_processing_ctx.inventory_id = deleted_host.id
def row2dict(row):
"""将对象(一般为orm row)转换为dict"""
record = {}
# 清除掉过期状态，强制的跳过state._load_expired(state, passive)
# 如果有字段确实需要而没有的，要么设置default值，要么使用refresh从数据库拿到server_default值
state = instance_state(row)
state.expired_attributes.clear()
attributes, cls = deepcopy(row.__dict__), row.__class__
for c in dir(row):
if hasattr(cls, c):
a = getattr(cls, c)
# hybrid_property
if isinstance(a, QueryableAttribute) and not isinstance(
a, InstrumentedAttribute):
attributes[c] = 1 # 这里只需要有attribute name就可以了
for c in attributes:
if not c.startswith('_') and 'metadata' != c:
try:
v = row.__getattribute__(c)
except KeyError as e: # https://github.com/zzzeek/sqlalchemy/blob/master/lib/sqlalchemy/orm/attributes.py#L579 这个函数可能会raise KeyError出来
logging.exception(e)
v = datetime.now() if c in ['created', 'modified'] else None
if isinstance(v, Base):
v = row2dict(v)
if isinstance(v, Decimal):
v = int(v)
# 特殊处理一下生日，以及开始时间结束时间
if c in ['start', 'end'
] and row.__tablename__ in ['work', 'education']:
v = v.strftime('%Y.%m')
if c in ['birthday'] and row.__tablename__ in ['user']:
v = v.strftime('%Y.%m.%d')
if isinstance(v, datetime):
v = v.strftime('%Y.%m.%d %H:%M:%S')
if isinstance(v, InstrumentedList):
v = list(map(lambda i: row2dict(i), v))
record[c] = v
return record
def validate(self):
old = instance_state(self).committed_state
# check all accounts related to the splits of the transaction are not placeholder(=frozen)
for sp in self.splits:
if sp.account.placeholder != 0:
raise GncValidationError("Account '{}' used in the transaction is a placeholder".format(sp.account))
# check same currency
if "currency" in old and old["currency"] is not None:
raise GncValidationError("You cannot change the currency of a transaction once it has been set")
# validate the splits
if "splits" in old:
value_imbalance, quantity_imbalances = self.calculate_imbalances()
if value_imbalance:
# raise exception instead of creating an imbalance entry as probably an error
# (in the gnucash GUI, another decision taken because need of "save unfinished transaction")
raise GncImbalanceError("The transaction {} is not balanced on its value".format(self))
if any(quantity_imbalances.values()) and self.book.use_trading_accounts:
self.normalize_trading_accounts()
def tojson(self,
request,
instance,
in_list=False,
exclude=None,
exclude_related=None,
safe=False,
**kw):
instance = self.instance(instance)
obj = instance.obj
if instance_state(obj).detached:
with self.session(request) as session:
session.add(obj)
return self.tojson(request,
instance,
in_list=in_list,
exclude_related=exclude_related,
safe=safe,
exclude=exclude,
**kw)
info = self._fields
exclude = info.exclude(exclude, exclude_urls=True)
load_only = instance.fields
fields = {}
for field in self.fields().values():
name = field.name
if name in exclude or (load_only and name not in load_only):
continue
try:
data = self.get_instance_value(instance, name)
if isinstance(data, date):
if isinstance(data, datetime) and not data.tzinfo:
data = pytz.utc.localize(data)
data = data.isoformat()
elif isinstance(data, Enum):
data = data.name
elif is_rel_field(field):
if exclude_related:
continue
model = request.app.models.get(field.model)
if model:
data = self._related_model(request, model, data,
in_list)
else:
data = None
request.logger.error('Could not find model %s',
field.model)
else: # Test Json
json.dumps(data)
except TypeError:
try:
data = str(data)
except Exception:
continue
except ObjectDeletedError:
raise ModelNotAvailable from None
except Exception:
if not safe:
request.logger.exception(
'Exception while converting attribute "%s" in model '
'%s to JSON', name, self)
continue
if data is not None:
if isinstance(data, list):
name = '%s[]' % name
fields[name] = data
return self.instance_urls(request, instance, fields)
def build_new_instance(self):
model = self._manager.new_instance()
model.__init__() # <-- Call SAFRSBase.__init__()
state = instance_state(model)
self._manager.dispatch.init(state, [], {})
return model
def get_names_excluded_from(cls, obj: object) -> Set[str]:
""" Get the list of attribute names that SALoadedGetterDict has excluded
See SALoadedGetterDict._excluded
"""
return instance_state(obj).info[SALoadedGetterDict]
def object_beforechange(self):
return instance_state(self).committed_state
def from_instance(cls, instance: object):
state: InstanceState = instance_state(instance)
return cls(state.class_.__name__,
cls._instance_identity_to_str(state.identity))
