Relay class

Relay records the workflow in a tape recorder fashion. This helps in construction of the workflow as a directed-acyclic graph. The runner.relay.Relay emphasises simplicity, speed and flexibility in implementing the workflow.

class runner.relay.Relay(label, parents=None, runnerdata=None, runnername=None)

Relay db rows into a workflow

Parameters:

• label (str) – unique label of relay, for easy access in graph

• parents (list) – list of parents as input to the relay. Parents can be Atoms object, id in the database, or Relay.

• runnerdata (RunnerData) – the runner data to be attached to the row.

• runnername (str) – name of the runner that handles the row run.

Note

In the case of Atoms object as parent, the object can be the only one in the list.

cancel(cancel_all=False)

Cancel row job

Parameters:

all (bool) – Cancel all runs in the parent relay too.

commit(database=None)

Commits the relay to the database, i.e. adds data to the database.

Parameters:

database (str) – ASE database to commit to. If None (default) then stored database from previous commit is used.

Returns:

the id of the row commited to in the database.

Return type:

int

property database

database associated with the relay

classmethod from_database(index, database)

Get relay from database

Parameters:

• index (int) – id of row in database

• database (str) – ASE database

Returns:

relay associated with id

Return type:

Relay object

classmethod from_json(filename)

Get relay from json file.

Parameters:

filename (str) – json filename

get_parent_relay(item)

Returns a Relay instance of one of the parents associated with item, in the parent relay

Parameters:

item (str or int) – id or label associated with parent relay

get_relay_graph(filename, add_tasks=False)

Save the relay as a directional acyclic graph, with status

Parameters:

• filename (str) – png filename to save the graph

• add_tasks (bool) – adds task information to the graph

get_row(cycle_time=10, wait=True)

Get atoms row attached with the relay. Waits for the run if not finished.

Parameters:

• cycle_time (float) – time (s) to cycle the query.

• wait (bool) – wait for run to finish

Returns:

atoms row of attached with the relay

Return type:

row

get_status()

Returns status of the present row

Returns:

status of present row

Return type:

str

property label

runnername associated with the relay

list_parent_relay()

Returns a list of relay instances present in the relay.

needs_commit()

Checks all parents to confirm if relay needs a commit

Returns:

if relay needs a commit

Return type:

bool

Note

set_property methods should be used to update the relay. This marks the relay needs commit. If the set_property methods aren’t used, then relay will not commit the changes.

property parents

parents associated with the relay

replace_runnerdata(runnerdata)

Replace RunnerData for the relay and all relays with same runner name as the given RunnerData

Parameters:

runnerdata (RunnerData) – RunnerData to supplant.

property row

Atoms row attached with the relay, awaits for the run to finish

property runnerdata

runnerdata associated with the relay

property runnername

runnername associated with the relay

start(force=False, force_all=False)

Submits the relay for run. Rows with submitted parents are also submitted.

NB: rows with status ‘submit’ or ‘running’ are not

resubmitted.

Parameters:

• force (bool) – resubmit row with ‘done’ status too.

• force_all (bool) – resubmit all parent rows with ‘done’ status too.

Returns:

if a row is submitted

Return type:

bool

property status

Returns status of present relay row

to_json(filename)

Save the relay as a json file

Parameters:

filename (str) – json filename