data_event_handlers_http#

Handling of HTTP/REST-based data events.

This module contains Data Event Handler classes that manipulate events originating from the HTTP/REST interface of detectors manufactured by company Dectris.

class EigerHttpDataEventHandler(*, source, parameters)#

Data Event Handler for Eiger’s HTTP/REST events.

This class handles data events recovered from the HTTP/REST interface of an Eiger detector.

This class implements the interface described by its base Protocol class. Please see the documentation of that class for additional information about the interface.

For this Event Handler, a data event corresponds to the content of an individual event retrieved from the HTTP/REST interface (usually a single detector data frame)
The source string for this Data Event Handler is the base URL of the ‘monitor’ subsystem of the Eiger detector HTTP/REST interface. The string has the following format: http://<address_of_dcu>/monitor/api/<version>.

Parameters:

source (str) – A string describing the data event source.
data_sources –
A dictionary containing a set of Data Source class instances.
- Each dictionary key must define the name of a data source.
- The corresponding dictionary value must store the instance of the [Data Source class][om.protocols.data_retrieval_layer.OmDataSourceProtocol] # noqa: E501 that describes the source.
parameters (DataRetrievalLayerParameters) – An object storing OM’s configuration parameters.

designated_collector_rank()#

Return type:: Literal[‘first’, ‘last’]

skip_rank_finalization()#

Return type:: bool

initialize_event_handling_on_collecting_node(*, node_rank, node_pool_size)#

Initializes Eiger’s HTTP/REST event handling on the collecting node.

Please see the documentation of the base Protocol class for additional information about this method.

Parameters:

node_rank (int) – The OM rank of the current node int the OM node pool. The rank is an integer that unambiguously identifies the node in the pool.
node_pool_size (int) – The total number of nodes in the OM pool, including all the processing nodes and the collecting node.

Raises:

OmHttpInterfaceInitializationError – Raised when an error happens during the initialization of the Eiger’S HTTP/REST interface.

Return type:

None

initialize_event_handling_on_processing_node(*, node_rank, node_pool_size)#

Initializes Eiger’s HTTP/REST event handling on the processing nodes.

Please see the documentation of the base Protocol class for additional information about this method.

Parameters:

node_rank (int) – The OM rank of the current node int the OM node pool. The rank is an integer that unambiguously identifies the node in the pool.
node_pool_size (int) – The total number of nodes in the OM pool, including all the processing nodes and the collecting node.

Returns:

An optional initialization token.

Return type:

Any

event_generator(*, node_rank, node_pool_size)#

Retrieves events from Eiger’s HTTP/REST interface.

Please see the documentation of the base Protocol class for additional information about this method.

This function retrieves data events on the processing nodes. Each retrieved event corresponds to a single event from Eiger’s HTTP/REST interface (a single detector data frame).

Parameters:

node_rank (int) – The OM rank of the current node int the OM node pool. The rank is an integer that unambiguously identifies the node in the pool.
node_pool_size (int) – The total number of nodes in the OM pool, including all the processing nodes and the collecting node.

Return type:

Generator[dict[str, Any], None, None]

extract_data(*, event)#

Extracts data from an Eiger HTTP/REST event.

Please see the documentation of the base Protocol class for additional information about this method.

Parameters:

event (dict[str, Any]) – A dictionary storing the event data.

Returns:

A dictionary storing the extracted data.

Each dictionary key identifies a Data Source in the event for which data has been retrieved.

The corresponding dictionary value stores the data extracted from the Data Source for the event being processed.

Raises:

OmDataExtractionError – Raised when data cannot be extracted from the event.

Return type:

dict[str, Any]

initialize_event_data_retrieval()#

Initializes event data retrievals from from Eiger’s HTTP/REST interface.

Eiger’s HTTP/REST interface does not allow the retrieval of single standalone data events, so this function has no implementation.

Please see the documentation of the base Protocol class for additional information about this method.

Raises:: NotImplementedError – This functionality has not been implemented for this Data Event Handler.
Return type:: None

retrieve_event_data(event_id)#

Retrieves all data related to the requested event.

Please see the documentation of the base Protocol class for additional information about this method.

Eiger’s HTTP/REST interface does not allow the retrieval of standalone data events, so this function has no implementation.

Parameters:: event_id (str) – A string that uniquely identifies a data event.
Returns:: All data related to the requested detector event.
Raises:: NotImplementedError – This functionality has not been implemented for this Data Event Handler.
Return type:: dict[str, Any]