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Close the session opened when user information is queried.
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This may fix the problem of psql sessions not closing, requiring
application restarts.
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@aholmes
aholmes committed Aug 1, 2024
1 parent 8aca846 commit c562046
Showing 1 changed file with 82 additions and 81 deletions.
163 changes: 82 additions & 81 deletions src/platform/BL_Python/platform/identity/user_loader.py
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Original file line number Diff line number Diff line change
Expand Up @@ -89,102 +89,103 @@ def user_loader(
:raises AssertionError: If a user is loaded from the database, but it is not of the type specified by user_table.
"""
session = self._scoped_session()

self._log.debug(f'Loading user "{username}"')

if not username:
self._log.warn("`username` is empty. Skipping load.")
return

try:
# SQLAlchemy generates invalid SQL when attempting an implicit
# LEFT JOIN between user -> user_role and user_role -> role.
# As such, we handle the join explicitly by extracting the property
# relationships and referencing the relevant columns.
user_table_property_mapper = cast(Mapper, class_mapper(self._user_table))
user_table_properties = cast(
"list[RelationshipProperty[DbRole] | ColumnProperty]",
user_table_property_mapper.iterate_properties, # pyright: ignore[reportUnknownMemberType]
)
# Only extract the secondary join table (user_role).
# We find this by matching on the `role` table relationship
# from the `user` table.
user_role_table = next(
relationship.secondary
for relationship in user_table_properties
if (entity := getattr(relationship, "entity", None))
and entity.class_ == self._role_table
)

user = (
session.query(self._user_table)
# These two `outerjoin` calls define the explicit
# join conditions between the `user` and `role` tables,
# and the secondary join table `user_role`.
.outerjoin(
user_role_table,
user_role_table.c.user_id == self._user_table.user_id,
with self._scoped_session() as session:
try:
# SQLAlchemy generates invalid SQL when attempting an implicit
# LEFT JOIN between user -> user_role and user_role -> role.
# As such, we handle the join explicitly by extracting the property
# relationships and referencing the relevant columns.
user_table_property_mapper = cast(
Mapper, class_mapper(self._user_table)
)
.outerjoin(
self._role_table,
user_role_table.c.role_id == self._role_table.role_id,
user_table_properties = cast(
"list[RelationshipProperty[DbRole] | ColumnProperty]",
user_table_property_mapper.iterate_properties, # pyright: ignore[reportUnknownMemberType]
)
# Only extract the secondary join table (user_role).
# We find this by matching on the `role` table relationship
# from the `user` table.
user_role_table = next(
relationship.secondary
for relationship in user_table_properties
if (entity := getattr(relationship, "entity", None))
and entity.class_ == self._role_table
)
.filter(self._user_table.username == username)
.one_or_none()
)

self._log.debug(f'Queried for "{username}" in database')

if create_if_new_user and user is None:
self._log.info(
f'User "{username}" does not already exist in the database'
user = (
session.query(self._user_table)
# These two `outerjoin` calls define the explicit
# join conditions between the `user` and `role` tables,
# and the secondary join table `user_role`.
.outerjoin(
user_role_table,
user_role_table.c.user_id == self._user_table.user_id,
)
.outerjoin(
self._role_table,
user_role_table.c.role_id == self._role_table.role_id,
)
.filter(self._user_table.username == username)
.one_or_none()
)

if default_role is None:
user = self._user_table(username=username)
else:
role = (
session.query(self._role_table)
.filter(self._role_table.role_name == default_role.name)
.one()
self._log.debug(f'Queried for "{username}" in database')

if create_if_new_user and user is None:
self._log.info(
f'User "{username}" does not already exist in the database'
)

user = self._user_table(username=username, roles=[role])
if default_role is None:
user = self._user_table(username=username)
else:
role = (
session.query(self._role_table)
.filter(self._role_table.role_name == default_role.name)
.one()
)

user = self._user_table(username=username, roles=[role])

session.add(user)
session.commit()

self._log.info(f'User "{username}" added to the database')
elif user is None:
self._log.info(
"Username does not exist. Refusing to create a new user. This happens when a username (likely from a cookie)\
cannot be found in the database, and the process should not create a new user."
)
return
else:
self._log.debug(f'User "{username}" loaded from the database')

session.add(user)
session.commit()
if not isinstance(user, self._user_table):
raise AssertionError(
f"User object queried from database is unexpected type `{type(user)}`. Expected type `{type(self._user_table)}`."
)

self._log.info(f'User "{username}" added to the database')
elif user is None:
self._log.info(
"Username does not exist. Refusing to create a new user. This happens when a username (likely from a cookie)\
cannot be found in the database, and the process should not create a new user."
user_roles = dict(self._roles.__members__.items())
roles = cast(
Sequence[Role],
[user_roles[user_role.role_name] for user_role in user.roles],
)
return
else:
self._log.debug(f'User "{username}" loaded from the database')

if not isinstance(user, self._user_table):
raise AssertionError(
f"User object queried from database is unexpected type `{type(user)}`. Expected type `{type(self._user_table)}`."
return self._loader(
UserId(
user_id=user.user_id,
username=user.username,
),
roles,
)

user_roles = dict(self._roles.__members__.items())
roles = cast(
Sequence[Role],
[user_roles[user_role.role_name] for user_role in user.roles],
)

return self._loader(
UserId(
user_id=user.user_id,
username=user.username,
),
roles,
)
except:
self._log.exception(
f'Error when loading user "{username}" from the database.'
)
raise
except:
self._log.exception(
f'Error when loading user "{username}" from the database.'
)
raise

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