Line data Source code
1 : //--------------------------------------------------------------------------
2 : #ifndef HEPMC_IO_BASECLASS_H
3 : #define HEPMC_IO_BASECLASS_H
4 :
5 : //////////////////////////////////////////////////////////////////////////
6 : // Matt.Dobbs@Cern.CH, November 1999, refer to:
7 : // M. Dobbs and J.B. Hansen, "The HepMC C++ Monte Carlo Event Record for
8 : // High Energy Physics", Computer Physics Communications (to be published).
9 : //
10 : // event input/output base class
11 : //////////////////////////////////////////////////////////////////////////
12 : //
13 : // class from which all input/output classes shall inherit from.
14 : // i.e.: if you want to write events to hbook ntuples,
15 : // then inherit from this class and re-define read_event()
16 : // and write_event()
17 : //
18 : // (Possible extension: Could make this an input iterator)
19 : //
20 :
21 : #include <iostream>
22 : #include "HepMC/GenEvent.h"
23 :
24 : namespace HepMC {
25 :
26 : //! all input/output classes inherit from IO_BaseClass
27 :
28 : ///
29 : /// \class IO_BaseClass
30 : /// If you want to write a new IO class,
31 : /// then inherit from this class and re-define read_event()
32 : /// and write_event()
33 : ///
34 0 : class IO_BaseClass {
35 : public:
36 0 : virtual ~IO_BaseClass() {}
37 :
38 : /// write this GenEvent
39 : virtual void write_event( const GenEvent* ) =0;
40 : /// fill this GenEvent
41 : virtual bool fill_next_event( GenEvent* ) =0;
42 : /// write output to ostr
43 : virtual void print( std::ostream& ostr = std::cout ) const;
44 : //
45 : // the read_next_event() differs from
46 : // the fill_***() methods in that it creates a new event
47 : // before calling the corresponding fill_*** method
48 : // (they are not intended to be over-ridden)
49 : GenEvent* read_next_event(); //!< do not over-ride
50 : //
51 : // The overloaded stream operators >>,<< are identical to
52 : // read_next_event and write_event methods respectively.
53 : // (or read_particle_data_table and write_particle_data_table)
54 : // the event argument for the overloaded stream operators is a pointer,
55 : // which is passed by reference.
56 : // i.e. GenEvent* evt;
57 : // io >> evt;
58 : // will give the expected result.
59 : // (note: I don't see any reason to have separate const and non-const
60 : // versions of operator<<, but the pedantic ansi standard insists
61 : // on it)
62 : /// the same as read_next_event
63 : virtual GenEvent*& operator>>( GenEvent*& );
64 : /// the same as write_event
65 : virtual const GenEvent*& operator<<( const GenEvent*& );
66 : /// the same as write_event
67 : virtual GenEvent*& operator<<( GenEvent*& );
68 : };
69 :
70 : //////////////
71 : // Inlines //
72 : //////////////
73 :
74 : inline GenEvent* IO_BaseClass::read_next_event() {
75 : /// creates a new event and fills it by calling
76 : /// the sister method read_next_event( GenEvent* )
77 : //
78 : // 1. create an empty event container
79 0 : GenEvent* evt = new GenEvent();
80 : // 2. fill the evt container - if the read is successful, return the
81 : // pointer, otherwise return null and delete the evt
82 0 : if ( fill_next_event( evt ) ) return evt;
83 : // note: the below delete is only reached if read fails
84 : // ... thus there is not much overhead in new then delete
85 : // since this statement is rarely reached
86 0 : delete evt;
87 0 : return 0;
88 0 : }
89 :
90 : inline void IO_BaseClass::print( std::ostream& ostr ) const {
91 0 : ostr << "IO_BaseClass: abstract parent I/O class. " << std::endl;
92 0 : }
93 :
94 : inline GenEvent*& IO_BaseClass::operator>>( GenEvent*& evt ){
95 0 : evt = read_next_event();
96 0 : return evt;
97 : }
98 :
99 : inline const GenEvent*& IO_BaseClass::operator<<(
100 : const GenEvent*& evt ) {
101 0 : write_event( evt );
102 0 : return evt;
103 : }
104 :
105 : inline GenEvent*& IO_BaseClass::operator<<( GenEvent*& evt ) {
106 0 : write_event( evt );
107 0 : return evt;
108 : }
109 :
110 : } // HepMC
111 :
112 : #endif // HEPMC_IO_BASECLASS_H
113 : //--------------------------------------------------------------------------
114 :
115 :
116 :
|
