#include <CRingMarkingWorker>
class CRingMarkingWorker : public CParallelWorker
{
public:
class Classifier {
public:
virtual uint32_t operator()(CRingItem& item) = 0;
};
public:
CRingMarkingWorker(
CFanoutClientTransport& fanin, CSender& sink, uint64_t clientId,
Classifier* pClassifier
);
virtual ~CRingMarkingWorker() {}
virtual void process(void* pData, size_t nBytes);
};
One of the main purposes of the parallel processing framework is to set up software triggers. In NSCLDAQ these operate in two stages. The first stage classifies ring items with a uint32_t value. The second stage retains or discards items by applying an acceptance criterion to this classification.
Note that only PHYSICS_EVENT items get classified. The classification is carried with the ring item as an extension to that item's body header. This class provides a framework that allows the user to simply report back the classification. All the work of getting work items, formatting the output ring items and sending them on to the next stage of processing are taken care of by this class.
The data processed by this class are assumed to have come
from a CRingItemZMQDataSource
or any other data source that produces the
same output format. The data source is
assumed to be a fanout data source as classification
may be computationally intensive enough to
be worth parallelization.
Construction of one of these therefore requires:
faninThe fanout client transport that is getting data from the fanout transport.
sinkThe sender that will be used to ship the resulting work items to the next stage of processing.
clientId
The client id that will be configured
into fanin
pClassifier
A pointer to a concrete subclass of
CRingMarkingWorker::Classfier.
This is an application specific class who's
operator() knows
how to compute and return the
uint32_t classification of a ring item
passed by reference.
Data sent on the sink will
have the same format as the data received, however
each block containing a physics item
will be a uint32_t longer than before
to accomodate the classification value. The
ring item size and body header size field will be
modified to appropriately reflect this.
The messages sent by this class are suitable
for input to the
CRingItemSorter(3daq).
The consist of first a uint32_t client id followed
by an array of timestamp, ring items pairs
The message size and
iterating through the ring items can be used to
determine the number of ring items present.