JFactory.h

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// $Id: JFactory.h 1733 2006-05-02 17:17:32Z davidl $


#ifndef _JFACTORY_H_
#define _JFACTORY_H_



#include "JObject.h"


#include <vector>
#include <string>
using std::vector;
using std::string;

#include "JEventLoop.h"
#include "JFactory_base.h"
#include "JEvent.h"

// The following is here just so we can use ROOT's THtml class to generate documentation.
#ifdef __CINT__
class pthread_mutex_t;
typedef unsigned long pthread_t;
typedef unsigned long oid_t;
#endif

// Place everything in JANA namespace
namespace jana{

///
/// JANA Data Factory (base class for algorithms)
///
/// All data (except that read from the data source) must
/// be derived from the data that was read from the source.
/// One JFactory object should exist for each type of data
/// that is "generated". For example: Clusters in a calorimeter
/// are generated from individual "Hits" in the calorimeter.
/// 
/// JFactory is the templated base class which all factories
/// are derived from.
///
/// At the user level, factory classes will be defined
/// which inherit from this templated base class. By
/// inheriting from a template, the derived factory class
/// will automatically have a high degree of type safety
/// since the "_data" vector will be specific to the type
/// of objects the factory produces. This class (JFactory)
/// inherits from JFactory_base so that all factories can
/// be treated equally (polymorphism) by the JEventLoop object.
///
/// Instantiating a JFactory<T> object itself would be pointless
/// since they would use the default  init(), brun(),evnt(),erun(),
/// and fini()
/// methods from JEventProcessor which do nothing. Instead,
/// A new class should be derived from this one which implements
/// its own init(), brun(),evnt(),erun(), and fini() methods.

//-----------------------
// class JFactory
//-----------------------
template<class T>
class JFactory:public JFactory_base{
   
   public:
      JFactory(const char *tag="");
      ~JFactory();

      enum data_origin_t{
         ORIGIN_NONE,
         ORIGIN_FACTORY,
         ORIGIN_EXTERNAL
      };
      
      vector<void*>& Get(void);
      jerror_t Get(vector<const T*> &d);
      int GetNrows(void);
      data_origin_t GetDataOrigin(void){return data_origin;}
      inline const char* className(void){return T::static_className();}
      inline const char* GetDataClassName(void){return className();}
      inline void toStrings(vector<vector<pair<string,string> > > &items, bool append_types=false) const;
      virtual const char* Tag(void){return tag_str;}
      inline int GetDataClassSize(void){return sizeof(T);}
      inline int GetEventCalled(void){return evnt_called;}
      inline int GetCheckSourceFirst(void){return !use_factory;}
      jerror_t CopyFrom(vector<const T*> &data);
      jerror_t CopyTo(vector<T*> &data);
      const T* GetByIDT(JObject::oid_t id);
      const JObject* GetByID(JObject::oid_t id){return dynamic_cast<const JObject*>(GetByIDT(id));}
      

   protected:
      vector<T*> _data;
      vector<void*>_vdata;
      int use_factory;
      const char* tag_str;
      
      jerror_t Reset(void);
      jerror_t HardReset(void);
      
      data_origin_t data_origin;
};


// The following is here just so we can use ROOT's THtml class to generate documentation.
#ifndef __CINT__

//-------------
// JFactory
//-------------
template<class T>
JFactory<T>::JFactory(const char *tag)
{
   /// This is a base class that specific factories inherit from.
   /// my_devent will be kept and used to allow this factory to
   /// access other factories.

   // make sure vector is empty
   _data.clear(); // probably unnecessary
   
   // clear flags
   flags = WRITE_TO_OUTPUT;
   use_factory = 0;
   busy = 0;
   tag_str = tag;
   Ncalls_to_Get = 0;
   Ncalls_to_evnt = 0;

   // Allow any factory to have its debug_level set via environment variable
   debug_level = 0;
   string envar = string() + "DEBUG_" + GetDataClassName();
   char *ptr = getenv(envar.c_str());
   if(ptr)debug_level = atoi(ptr);
}

//-------------
// ~JFactory
//-------------
template<class T>
JFactory<T>::~JFactory()
{
   /// Delete all objects in _data container.
   HardReset();
}

//-------------
// Get
//-------------
template<class T>
vector<void*>& JFactory<T>::Get(void)
{
   /// Return a STL vector of pointers to the objects produced by the
   /// factory. The pointers are type cast as void* so this can be
   /// accessed through the JFactory_base base class. This just
   /// dispatches to the type specific Get(vector<const T*> &)
   /// method.
   vector<const T*> d;
   Get(d);
   
   // Copy the pointers into a vector of void*s.
   _vdata.clear();
   for(unsigned int i=0;i<_data.size();i++)_vdata.push_back((void*)_data[i]);
   
   return _vdata;
}

//-------------
// Get
//-------------
template<class T>
jerror_t JFactory<T>::Get(vector<const T*> &d)
{
   /// Copy pointers to the objects produced by the factory into
   /// the vector reference passed. 
   /// Note that this method is accessed primarily from two places:
   /// This main one is JEventLoop::GetFromFactory which is called
   /// from JEventLoop::Get , the primary access method for factories
   /// and event processors.
   /// The second is through the JFactory<T>::Get() which is called
   /// through the JFactory_base::Get virtual method.
   /// That is used mainly by things that need to loop over all
   /// objects of all factories.
   ///
   /// This method will check first to make sure this factory hasn't
   /// already been called for this event.
   ///
   /// This also uses a busy flag to ensure we're not called
   /// recursively. i.e. we call a factory who calls another
   /// factory who eventually calls us. An exception is thrown
   /// (type jerror_t) with a value INFINITE_RECURSION if that
   /// situation is detected.
   
   
   // If evnt_called is set, then just copy the pointers and return
   if(evnt_called)return CopyFrom(d);
   
   // Check for infinite recursion through factory dependancies
   if(busy)throw(INFINITE_RECURSION);
   busy++;
   if(busy!=1)throw(INFINITE_RECURSION);  // Should we use a mutex here?
   
   // Grab the current event and run numbers
   int event_number = eventLoop->GetJEvent().GetEventNumber();
   int run_number = eventLoop->GetJEvent().GetRunNumber();
   
   // Make sure we're initialized
   if(!init_called){
      init();
      init_called = 1;
   }
   
   // Call brun routine if run number has changed or it's not been called
   if(run_number!=brun_runnumber){
      if(brun_called && !erun_called){
         erun();
         erun_called = 1;
      }
      brun_called = 0;
   }
   if(!brun_called){
      brun(eventLoop, run_number);
      brun_called = 1;
      erun_called = 0;
      brun_runnumber = run_number;
   }
   
   // Call evnt routine to generate data
   try{
      Ncalls_to_evnt++;
      evnt(eventLoop, event_number);
      CopyFrom(d);
   }catch(JException *exception){
      JEventLoop::error_call_stack_t cs;
      cs.factory_name = GetDataClassName();
      cs.tag = Tag();
      cs.filename = __FILE__;
      cs.line = __LINE__;
      eventLoop->AddToErrorCallStack(cs);
      throw exception;
   }
   evnt_called = 1;
   busy=0;
   
   return NOERROR;
}

//-------------
// GetNrows
//-------------
template<class T>
int JFactory<T>::GetNrows(void)
{
   /// Return the number of objects for this factory for the
   /// current event. If the objects have not yet been created
   /// for the event, this will cause them to be generated 
   /// (or retreived from the source).
   if(!evnt_called){
      // In order to get the objects from the source, the Get() method
      // of the JEventLoop object must be called. This may seem
      // convoluted, but it's neccessary for things like janadump
      // that only have a list of JFactory_base pointers and
      // are not able to call the templated JEventLoop::Get()
      // method directly.
      // Note that we must use the Tag() method so it will pass
      // the tag from the subclass (if any). The tag_str member
      // is only in JFactory for when sources must auto-instantiate
      // a JFactory<> class.
      vector<const T*> d; // dummy placeholder
      eventLoop->Get(d,Tag());
   }
   
   return _data.size();
}

//-------------
// Reset
//-------------
template<class T>
jerror_t JFactory<T>::Reset(void)
{
   /// Clear out the factories current contents unless the
   /// PERSISTANT flag is set.
   if(flags & (unsigned int)PERSISTANT)return NOERROR;

   // don't reset the evnt_called flag for persistent data because this
   // will force evnt to be called next event therby regenerating
   // the data
   
   return HardReset();
}

//-------------
// HardReset
//-------------
template<class T>
jerror_t JFactory<T>::HardReset(void)
{
   
   /// Clear out the factories current contents.
   if(!TestFactoryFlag(NOT_OBJECT_OWNER)){
      for(unsigned int i=0;i<_data.size();i++){
         delete _data[i];
      }
   }
   _data.clear();

   evnt_called = 0;
   
   return NOERROR;
}

//-------------
// CopyTo
//-------------
template<class T>
jerror_t JFactory<T>::CopyTo(vector<T*> &data)
{
   /// Copy object pointers into factory. Object ownership is
   /// transferred to the factory here so the caller should not
   /// delete the objects after calling this unless the factory's
   /// NOT_OBJECT OWNER flag is set (see
   /// SetFactoryFlag(JFactory_base::NOT_OBJECT_OWNER))
   /// This is how an external source such as a file can create
   /// the objects and put them in the factory. The objects will
   /// then be treated as though they were generated by the factory.
   /// i.e. they will be returned in subsequent calls to Get()
   /// and deleted at the start of the next event (sans 
   /// the NOT_OBJECT_OWNER or PERSISTANT flags).

   // Set flag so subsequent calls for this event will return this
   // data.
   evnt_called = 1;
      
   // Just copy into the _vdata vector since _data is not used outside
   // of the factory.
   _data.clear();
   for(unsigned int i=0;i<data.size();i++){
      _data.push_back(data[i]);
   }

   return NOERROR;
}

//-------------
// CopyFrom
//-------------
template<class T>
jerror_t JFactory<T>::CopyFrom(vector<const T*> &data)
{
   /// Copy object pointers from private vector into "data"
   /// vector. This does not check if the evnt() routine
   /// was called, and it does not generate the data objects
   /// (use the Get(vector<const T*>) method for that).
   /// This only copies pointers to already existing objects.
   for(unsigned int i=0;i<_data.size(); i++)data.push_back(_data[i]);
   Ncalls_to_Get++;
   
   return NOERROR;
}

//-------------
// GetByIDT
//-------------
template<class T>
const T* JFactory<T>::GetByIDT(JObject::oid_t id)
{
   for(unsigned int i=0;i<_data.size();i++)
      if(_data[i]->id == id)return (const T*)_data[i];
   return NULL;
}

//-------------
// toStrings
//-------------
template<class T>
void JFactory<T>::toStrings(vector<vector<pair<string,string> > > &items, bool append_types) const
{
   /// Get the data for all objects already created by this factory for the
   /// given event by calling the toStrings() method of each one.
   ///
   /// Note that this will not activate the factory to generate the objects
   /// if they do not already exist.
   ///
   /// The value of <i>append_types</i> is used to set the append_types
   /// flag for each of the objects prior to calling its <i>toStrings</i>
   /// method. Afterwards, the value of the objects' append_types flag
   /// is reset to whatever value it had upon entry. Please see the documentation
   /// of the AddString method of JObject for more details on what this
   /// flag does.
   ///
   /// The items vector is cleared upon entry.
   
   items.clear();
   
   for(unsigned int i=0;i<_data.size();i++){
      vector<pair<string, string> > myitems;
      bool save_append_types = _data[i]->GetAppendTypes();
      _data[i]->SetAppendTypes(append_types);
      _data[i]->toStrings(myitems);
      _data[i]->SetAppendTypes(save_append_types);
      if(myitems.size()>0)items.push_back(myitems);
   }
}

#endif //__CINT__


} // Close JANA namespace



#endif // _JFACTORY_H_

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