flowserv.model.workflow.state module

Definition of workflow states. The classes in this module represent the different possible states of a workflow run. There are four different states: (PENDING) the workflow run has been submitted and is waiting to start running, (RUNNING) the workflow is actively executing at the moment, (ERROR) workflow execution was interrupted by an error or canceled by the user, (SUCCESS) the workflow run completed successfully.

Contains default methods to (de-)serialize workflow state.

flowserv.model.workflow.state.CANCELED = ['canceled at user request']

Definition of state type identifier.

flowserv.model.workflow.state.STATE_SUCCESS = 'SUCCESS'

Short cut to list of active states.

class flowserv.model.workflow.state.StateCanceled(created_at: str, started_at: Optional[str] = None, stopped_at: Optional[str] = None, messages: Optional[List[str]] = None)

Bases: flowserv.model.workflow.state.WorkflowState

Cancel state representation for a workflow run. The workflow has three timestamps: the workflow creation time, workflow run start time and the time when the workflow was canceled. The state also maintains an optional list of messages.

class flowserv.model.workflow.state.StateError(created_at: str, started_at: Optional[str] = None, stopped_at: Optional[str] = None, messages: Optional[List[str]] = None)

Bases: flowserv.model.workflow.state.WorkflowState

Error state representation for a workflow run. The workflow has three timestamps: the workflow creation time, workflow run start time and the time at which the error occured (ot workflow was canceled). The state also maintains an optional list of error messages.

class flowserv.model.workflow.state.StatePending(created_at: Optional[str] = None)

Bases: flowserv.model.workflow.state.WorkflowState

State representation for a pending workflow that is waiting to start running. The workflow has only one timestamp representing the workflow creation time.

cancel(messages: Optional[List[str]] = None) → flowserv.model.workflow.state.StateCanceled

Get instance of canceled state for a pending wokflow.

Since the workflow did not start to run the started_at timestamp is set to the current time just like the stopped_at timestamp.

Parameters

messages (list(string), optional) – Optional list of messages

Return type

flowserv.model.workflow.state.StateCanceled

error(messages: Optional[List[str]] = None) → flowserv.model.workflow.state.StateError

Get instance of error state for a pending wokflow. If the exception that caused the workflow execution to terminate is given it will be used to create the list of error messages.

Since the workflow did not start to run the started_at timestamp is set to the current time just like the stopped_at timestamp.

Parameters

messages (list(string), optional) – Optional list of error messages

Return type

flowserv.model.workflow.state.StateError

start() → flowserv.model.workflow.state.StateRunning

Get instance of running state with the same create at timestamp as this state and the started at with the current timestamp.

Return type

flowserv.model.workflow.state.StateRunning

success(files: Optional[List[str]] = None) → flowserv.model.workflow.state.StateSuccess

Get instance of success state for a competed wokflow.

Parameters

files (list(string), default=None) – Optional list of created files (relative path).

Return type

flowserv.model.workflow.state.StateSuccess

class flowserv.model.workflow.state.StateRunning(created_at: str, started_at: Optional[str] = None)

Bases: flowserv.model.workflow.state.WorkflowState

State representation for a active workflow run. The workflow has two timestamps: the workflow creation time and the workflow run start time.

cancel(messages: Optional[List[str]] = None) → flowserv.model.workflow.state.StateCanceled

Get instance of class cancel state for a running wokflow.

Parameters

messages (list(string), optional) – Optional list of messages

Return type

flowserv.model.workflow.state.StateCanceled

error(messages: Optional[List[str]] = None) → flowserv.model.workflow.state.StateError

Get instance of error state for a running wokflow. If the exception that caused the workflow execution to terminate is given it will be used to create the list of error messages.

Parameters

messages (list(string), optional) – Optional list of error messages

Return type

flowserv.model.workflow.state.StateError

success(files: Optional[List[str]] = None) → flowserv.model.workflow.state.StateSuccess

Get instance of success state for a competed wokflow.

Parameters

files (list(string), default=None) – Optional list of created files (relative path).

Return type

flowserv.model.workflow.state.StateSuccess

class flowserv.model.workflow.state.StateSuccess(created_at: str, started_at: str, finished_at: Optional[str] = None, files: Optional[List[str]] = None)

Bases: flowserv.model.workflow.state.WorkflowState

Success state representation for a workflow run. The workflow has three timestamps: the workflow creation time, workflow run start time and the time when the workflow execution finished. The state also maintains handles to any files that were created by the workflow run.

class flowserv.model.workflow.state.WorkflowState(type_id: str, created_at: Optional[str] = None)

Bases: object

The base class for workflow states contains the state type identifier that is used by the different state type methods. The state also maintains the timestamp of workflow run creation. Subclasses will add additional timestamps and properties.

is_active() → bool

A workflow is in active state if it is either pending or running.

Return type

bool

is_canceled() → bool

Returns True if the workflow state is of type CANCELED.

Return type

bool

is_error() → bool

Returns True if the workflow state is of type ERROR.

Return type

bool

is_pending() → bool

Returns True if the workflow state is of type PENDING.

Return type

bool

is_running() → bool

Returns True if the workflow state is of type RUNNING.

Return type

bool

is_success() → bool

Returns True if the workflow state is of type SUCCESS.

Return type

bool

flowserv.model.workflow.state.deserialize_state(doc)

Create instance of workflow state from a given dictionary serialization.

Parameters

doc (dict) – Serialization if the workflow state

Return type

flowserv.model.workflow.state.WorkflowState

Raises

• KeyError –

• ValueError –

flowserv.model.workflow.state.serialize_state(state)

Create dictionary serialization if a given workflow state.

Parameters

state (flowserv.model.workflow.state.WorkflowState) – Workflow state

Return type

dict