#include <EventProcessor.h>
class CEventProcessor {
public:
virtual Bool_t operator()(const Address_t pEvent,
CEvent& rEvent,
CAnalyzer& rAnalyzer,
CBufferDecoder& rDecoder);
virtual Bool_t OnAttach(CAnalyzer& rAnalyzer);
virtual Bool_t OnBegin(CAnalyzer& rAnalyzer,
CBufferDecoder& rDecoder);
virtual Bool_t OnEnd(CAnalyzer& rAnalyzer,
CBufferDecoder& rBuffer);
virtual Bool_t OnPause(CAnalyzer& rAnalyzer,
CBufferDecoder& rDecoder);
virtual Bool_t OnResume(CAnalyzer& rAnalyzer,
CBufferDecoder& rDecoder);
virtual Bool_t OnOther(UInt_t nType,
CAnalyzer& rAnalyzer,
CBufferDecoder& rDecoder);
virtual Bool_t OnEventSourceOpen(std::string name);
virtual Bool_t OnEventSourceEOF();
virtual Bool_t OnInitialize();
};
CEventProcessor Provides the abstract
base class for elements of the event processing pipeline.
Tailoring SpecTcl to analyze a particular dataset involves
writing a set of classes derived from
CEventProcessor and registering instances
of those classes in
MySpecTclApp::CreateAnalysisPipeline.
Each element of the pipeline normally contributes elements to the event array either directly or indirectly through tree parameters. These elements, or parameter values, either come from decoding segments of the raw event, or by performing computations on existing parameter values.
Event processors that decode sections of the raw event are often referred to as unpackers.
Note that the methods of CEventProcessor
are all virtual methods that have default implementations
that return kfTRUE. All methods return
a Bool_t. A return value of kfTRUE
indicates success. A value of kfFALSE
indicates failure. A failure return aborts the event processing
pipeline. This means that no more event processors will be called
and, for operator() no histogramming
will be done on that event.
A common mistake for implementors of event processors is to forget to return a value. This can result in randomly and silently dropping events as return value will be not well defined.
virtual Bool_t operator()(const Address_t pEvent, CEvent& rEvent, CAnalyzer& rAnalyzer, CBufferDecoder& rDecoder);
This method is called for each physics event.
pEvent points to the raw
event data for this event. rEvent
is the array like object that stores the parameter values
created by the event processing pipeline for this event.
The rAnalyzer and
rDecoder parameters are
not often used but reference the analyzer and
buffer decoder objects used to manage event processing
for this event data format.
virtual Bool_t OnAttach(CAnalyzer& rAnalyzer);
Called when the event processor is registered
with the event processing pipeline.
rAnalyzer references
the analyzer that controls the flow of data
analysis through SpecTcl.
virtual Bool_t OnBegin(CAnalyzer& rAnalyzer, CBufferDecoder& rDecoder);
Called when a begin run item is detected. Note that not all data acquisition systems have begin run items, however all NSCL supported data acquisition systems do.
rAnalyzer and
rDecoder refer to the
analyzer and decoder respectively. The decoder
provides services (the run number and title
which again may not be available in non NSCL supported
data acquisition systems), that may be useful to
event processors that choose to implement this
method.
virtual Bool_t OnEnd(CAnalyzer& rAnalyzer, CBufferDecoder& rBuffer);
Called when an end fo run item is encountered.
See OnBegin for
more.
virtual Bool_t OnPause(CAnalyzer& rAnalyzer, CBufferDecoder& rDecoder);
Like OnBegin but invoked
when a run temporarily pauses. Note that not all
NSCL Supported data acquisition systems support
pausing an active run.
virtual Bool_t OnResume(CAnalyzer& rAnalyzer, CBufferDecoder& rDecoder);
Called when a paused run resumes.
virtual Bool_t OnOther(UInt_t nType, CAnalyzer& rAnalyzer, CBufferDecoder& rDecoder);
Called when an item type that does not neatly fit
into the categories above is encountered.
nType is an item type
drawn, where possible, from
buftype.h, and where not,
from the underlying DAQ system that produced the
data.
virtual Bool_t OnEventSourceOpen(std::string name);
Called when a new event source is opened.
name is a data source type
dependent parameter that identifies what the
data source is connected to.
virtual Bool_t OnEventSourceEOF();
Called when the event source hits the end of data. For file data sources this means that the data in the file has been completely processed. For Pipe data sources, this means that the producer end of the pipe has closed the pipe.
virtual Bool_t OnInitialize();
This is called when SpecTcl is initialized.
For event processors registered in
MySpecTclApp::CreateAnalysisPipeline,
this is sometime after registration when SpecTcl
has been completely intialized. For those
registered dynamically, later,
OnInitialize is called
immediately after
OnAttach.