Data Structures

This section contains the data structures that are used by the daqif interfaces daqif.OcmDaqControl, daqif.DpmControl and daqif.DpmDaqControl or used as pub/sub topic type.

class daqif.DaqState

Enumeration of top-level Data Acquisition states, see The Data Acquisition Process for additional details.

StateAcquiring: State that span the initial point it is created in OCM through the phase where data is acquired until all inputs for the Data Product have been created. See also StateAcquiring.

StateMerging: State that spans not where a Data Product is created from the acquired data. Phase where Data Product is created. See also StateMerging.

StateCompleted: Data Acquisition is completed.

StateUndefined: Only used for technical reasons. This is not an expected state.

class daqif.DaqSubState

Enumeration of possible Data Acquisition sub-states, see The Data Acquisition Process for additional details.

Note

Only a subset of the listed states are possible/valid in each DaqState.

NotStarted: Data Acquisition is created but not yet started.

Starting: Transitional state where Data Acquisition is being started. Some data sources might already be acquiring data. When all sources have started the Data Acquisition transitions to Acquiring.

Acquiring: Data is being acquired.

Stopping: Transitional state to Stopped. Some data sources might still be acquiring data and are about to be stopped. When all data sources have stopped the Data Acquisition transitions to Stopped.

Stopped: All data has been acquired.

Aborting: Transitional state where Data Acquisition remains while it is in the process of being aborted.

Aborted: If a Data Acquisition has errors or otherwise needs to be aborted the Data Acquisition also include the Aborted state.

NotScheduled: Before Data Acquisition is acknowledged by DPM it remains in NotScheduled.

Scheduled: Data Acquisition is acknowledged by DPM and is scheduled for merging (i.e. the Data Acquisition is in the backlog).

Collecting: Inputs for Data Product are being collected to DPM host in preparation for merging.

Merging: Data Product is being created by merging input files together.

Releasing: Data Product is being released to specified receivers, which in the normal case is OLAS.

Completed: Nominal final state for a Data Acquisition (i.e. final state when Data Acquisition is not aborted).

Undefined: Only used for technical reasons. This is not an expected state.

class daqif.DaqException

Exception used by OcmDaqControl.

id: str: Data Acquisition identifier.

message: str: Exception message.

class daqif.RuntimeError

Exception used when there is no Data Acquisition.

message: str: Exception message.

class daqif.DaqStatus

Contains the Data Acquisition status reply.

id: str: Data Acquisition identifier.

fileId: str: A unique OLAS compatible file id is assigned by daqOcmServer when Data Acquisition is started. This is also used as a basis for the Archive File Name and recoded as ARCFILE FITS keyword with only the addition of the FITS extension: {fileId}.fits[RD7].

See also

Archive File Name

state: DaqState: Data Acquisition state at the time the reply was sent.

substate: DaqSubState: Data Acquisition sub-state at the time the reply was sent.

timestamp: double: Timestamp of last status update.

error: boolean: A derived property that if set indicates that there is one or more issues with Data Acquisition. This is also the main mechanism for communicating asynchronous errors that cannot be communicated as part of a command reply. Attribute message contains the details.

message: str: Contains message related to current status. This is currently mainly used to provide information about active alerts.

result: str

Once Data Product has been created successfully in state Merging this property will contain the file path.

To ensure that result is available synchronize to substate Releasing or Completed.

New in version 2.0.0.

class daqif.DaqReply

Basic reply type that also indicate non-fatal errors.

id: str: Data Acquisition identifier.

error: boolean: When True this indicates Data Acquisition has one or more issues which can be read from DaqStatus.message.

class daqif.AwaitDaqReply

timeout: boolean: Indicates if the await request timed out before condition was fulfilled.

status: DaqStatus: Data Acquisition status when reply was sent.

class daqif.StorageStatus

Provides storage status information.

capacity: int: Partition size in number of bytes.

free: int: Free space on the file system in number of bytes.

available: int: Free space available to daqDpmServer, if non-privileged, in number of bytes. This may be less or equal to free.

class daqif.InternalDaqStatus: Structure used for internal communication between daqOcmServer and daqDpmServer. It is left undocumented on purpose and should not be used by end-users.

New in version 3.1.0.