FWLite/interface/EventSetup.h

0001 #ifndef DataFormats_FWLite_EventSetup_h
0002 #define DataFormats_FWLite_EventSetup_h
0003 // -*- C++ -*-
0004 //
0005 // Package:     FWLite
0006 // Class  :     EventSetup
0007 //
0008 /**\class EventSetup EventSetup.h DataFormats/FWLite/interface/EventSetup.h
0009
0010  Description: Provides access to conditions information from fwlite
0011
0012  Usage:
0013     This class provides a friendly interface for accessing conditions information
0014     which have been stored into a ROOT TFile.
0015
0016     As in the full framework, conditions data are collected in the EventSetup.  The
0017     EventSetup holds 'Records' where each 'Record' holds data where all the data
0018     in one 'Record' is valid for the same period of time (referred to as an
0019     'Interval of Validity' or IOV for short).
0020
0021     The normal usage of this class is as follows
0022
0023     TFile condFile("conditions.root");
0024
0025     fwlite::EventSetup es(&condFile);
0026
0027     fwlite::RecordID fooID = es.recordID("FooRecord");
0028
0029     for(...) {  //looping over some event data
0030        //eventID and timestamp are obtained from the event
0031        es.syncTo(eventID, timestamp);
0032
0033        fwlite::ESHandle<Foo> fooHandle;
0034        es.get(fooID).get(fooHandle);
0035
0036        //now access the info in Foo
0037       std::cout << fooHandle->value()<<std::endl;
0038     }
0039
0040     NOTE: This class is not safe to use across threads
0041 */
0042 //
0043 // Original Author:
0044 //         Created:  Thu Dec 10 15:57:46 CST 2009
0045 //
0046
0047 // system include files
0048 #include <vector>
0049 #include <string>
0050
0051 // user include files
0052 #include "DataFormats/Provenance/interface/EventID.h"
0053 #include "DataFormats/Provenance/interface/Timestamp.h"
0054 #include "FWCore/Utilities/interface/propagate_const.h"
0055 #include "FWCore/Utilities/interface/thread_safety_macros.h"
0056
0057 // forward declarations
0058 class TFile;
0059
0060 namespace edm {
0061   class EventBase;
0062 }
0063
0064 namespace fwlite {
0065   class Record;
0066   typedef unsigned int RecordID;
0067
0068   class EventSetup {
0069   public:
0070     EventSetup(TFile*);
0071
0072     EventSetup(const EventSetup&) = delete;  // stop default
0073
0074     const EventSetup& operator=(const EventSetup&) = delete;  // stop default
0075
0076     virtual ~EventSetup();
0077
0078     // ---------- const member functions ---------------------
0079     const Record& get(const RecordID&) const;
0080
0081     /**Returns the lookup id of the record whose name is iRecordName.  The returned id
0082       is only valid for the instance of an EventSetup object to which the recordID call was made.
0083       If you later create a new EventSetup instance even for the same file the RecordIDs can be different.
0084       */
0085     RecordID recordID(const char* iRecordName) const;
0086
0087     /**Returns true if a record with the name iRecordName is available in the file
0088       */
0089     bool exists(const char* iRecordName) const;
0090
0091     std::vector<std::string> namesOfAvailableRecords() const;
0092     // ---------- static member functions --------------------
0093
0094     // ---------- member functions ---------------------------
0095     //void syncTo(unsigned long iRun, unsigned long iLumi);
0096     //void syncTo(const edm::EventID&);
0097
0098     /** Ensures that all Records will access the appropriate data for this instant in time
0099       */
0100     void syncTo(const edm::EventID&, const edm::Timestamp&);
0101
0102     //void autoSyncTo(const edm::EventBase&);
0103
0104   private:
0105     // ---------- member data --------------------------------
0106     edm::EventID m_syncedEvent;
0107     edm::Timestamp m_syncedTimestamp;
0108
0109     //This class is not inteded to be used across different threads
0110     CMS_SA_ALLOW mutable TFile* m_file;
0111
0112     CMS_SA_ALLOW mutable std::vector<Record*> m_records;
0113   };
0114 }  // namespace fwlite
0115
0116 #endif