👌 IMPROVE: Check nodes are from same backend in validate_link

[chrisjsewell]

Since here:

aiida-core/aiida/storage/psql_dos/orm/nodes.py

Line 204 in bab1ad6

link = DbLink(input_id=source.id, output_id=self.id, label=link_label, type=link_type.value)

Only the node ID's are used to create the DbLink row, it would be possible currently to accidentally pass it two nodes associated with different backends, and so create an incorrect link.

We could possibly use the actual DbNodes, to instantiate the DbLink, and have sqlalchemy check that they are associated with the same Session,
but adding the check in validate_link should catch any issue earlier on, and make it backend agnostic.

[chrisjsewell]

FYI, this is how you would use source.bare_model/self.bare_model, instead of .id, and what would happen if the backends were different:

engine = sa.create_engine('sqlite:///:memory:', future=True, echo=False)
Base.metadata.create_all(engine)

session1 = Session(bind=engine, future=True)
session2 = Session(bind=engine, future=True)

node1 = DbNode(node_type='data.dict.dict', label='test1')
session1.add(node1)

node2 = DbNode(node_type='data.dict.dict', label='test2')
session2.add(node2)

link = DbLink(input=node1, output=node2, label='test', type='test')

session1.add(link)

InvalidRequestError: Object '<DbNode at 0x7fc6f3754700>' is already attached to session '9' (this is '8')

Perhaps could add this also 🤷

[sphuber]

Ran a quick benchmark to get a sense of the impact on performance and it seems negligible. Both get roughly 3.00 ms per loop when calling validate_link with %timeit in a loop.

[chrisjsewell]

Cool cheers, well if you're happy then I'm happy lol

[sphuber]

main

In [1]: from aiida.orm.utils.links import validate_link
   ...: from aiida.common.links import LinkType
   ...: a = CalcJobNode()
   ...: b = Int(2)

In [2]: %timeit validate_link(a, b, LinkType.CREATE, 'create')
2.9 ms ± 281 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

In [3]: %timeit validate_link(a, b, LinkType.CREATE, 'create')
2.89 ms ± 255 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

In [4]: %timeit validate_link(a, b, LinkType.CREATE, 'create')
2.7 ms ± 87.6 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

branch

In [1]: from aiida.orm.utils.links import validate_link
   ...: from aiida.common.links import LinkType
   ...: a = CalcJobNode()
   ...: b = Int(2)

In [2]: 

In [2]: %timeit validate_link(a, b, LinkType.CREATE, 'create')
2.73 ms ± 229 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

In [3]: %timeit validate_link(a, b, LinkType.CREATE, 'create')
2.87 ms ± 240 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

In [4]: %timeit validate_link(a, b, LinkType.CREATE, 'create')
2.62 ms ± 31.2 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

[sphuber]

Thanks @chrisjsewell