casacore
HDF5Object.h
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1 //# HDF5Object.h: An abstract base class representing an HDF5 object
2 //# Copyright (C) 2008
3 //# Associated Universities, Inc. Washington DC, USA.
4 //#
5 //# This library is free software; you can redistribute it and/or modify it
6 //# under the terms of the GNU Library General Public License as published by
7 //# the Free Software Foundation; either version 2 of the License, or (at your
8 //# option) any later version.
9 //#
10 //# This library is distributed in the hope that it will be useful, but WITHOUT
11 //# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 //# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13 //# License for more details.
14 //#
15 //# You should have received a copy of the GNU Library General Public License
16 //# along with this library; if not, write to the Free Software Foundation,
17 //# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18 //#
19 //# Correspondence concerning AIPS++ should be addressed as follows:
20 //# Internet email: aips2-request@nrao.edu.
21 //# Postal address: AIPS++ Project Office
22 //# National Radio Astronomy Observatory
23 //# 520 Edgemont Road
24 //# Charlottesville, VA 22903-2475 USA
25 //#
26 //# $Id$
27 
28 #ifndef CASA_HDF5OBJECT_H
29 #define CASA_HDF5OBJECT_H
30 
31 //# Includes
32 #include <casacore/casa/aips.h>
33 #include <casacore/casa/BasicSL/String.h>
34 
35 //# Define hid_t and hsize_t if not defined (thus if HDF5 disabled).
36 //# They should be the same as used by HDF5.
37 //# This is checked by functions check_hid_t and check_hsize_t.
38 #ifdef HAVE_HDF5
39 # include <hdf5.h>
40 #else
41  typedef int64_t hid_t;
42  typedef casacore::uInt64 hsize_t;
43 #endif
44 
45 
46 namespace casacore { //# NAMESPACE CASACORE - BEGIN
47 
48  // <summary>
49  // An abstract base class representing an HDF5 object
50  // </summary>
51 
52  // <use visibility=export>
53 
54  // <reviewed reviewer="" date="" tests="tHDF5Dataset.cc">
55  // </reviewed>
56 
57  // <synopsis>
58  // This class wraps a basic HDF5 object. It offers several benefits:
59  // <ul>
60  // <li> The most important is resource management. In case of an exception,
61  // the object's hid will automatically be closed by the destructor.
62  // <li> It acts as the base class for the basic objects file, group,
63  // and dataset.
64  // <li> An HDF5 hid is a kind of pointer and should not be copied.
65  // These classes forbid making a copy, but make it possible to use
66  // them in a shared pointer context.
67  // </ul>
68  // </synopsis>
69 
70  class HDF5Object
71  {
72  public:
73  // Default constructor sets to invalid hid.
75  : itsHid(-1)
76  {}
77 
78  // The destructor in a derived class should close the hid appropriately.
79  virtual ~HDF5Object();
80 
81  // Check if there is HDF5 support compiled in.
82  static Bool hasHDF5Support();
83 
84  // Close the hid if valid.
85  virtual void close() = 0;
86 
87  // Is it a valid hid?
88  bool isValid() const
89  { return itsHid >= 0; }
90 
91  // Get the hid.
92  hid_t getHid() const
93  { return itsHid; }
94 
95  // Convert automatically to hid_t.
96  operator hid_t() const
97  { return itsHid; }
98 
99  // Get or set the name.
100  // <group>
101  void setName (const String& name)
102  { itsName = name; }
103  const String& getName() const
104  { return itsName; }
105  // </group>
106 
107  // If no HDF5, throw an exception that HDF5 is not supported.
108  static void throwNoHDF5();
109 
110  protected:
111  // Set the hid.
112  void setHid (hid_t hid)
113  { itsHid = hid; }
114 
115  // Clear the hid (set to invalid).
116  void clearHid()
117  { itsHid = -1; }
118 
119  private:
120  //# Data members
121  //# Define a union to ensure that the object always uses 64 bits, even
122  //# for older HDF5 versions where hid_t is a 32 bit integer.
123  union {
124  hid_t itsHid;
125  int64_t itsDummyHid;
126  };
128 
129  private:
130  // Copy constructor cannot be used.
131  HDF5Object (const HDF5Object& that);
132  // Assignment cannot be used.
134  };
135 
136 
137 }
138 
139 #endif
const String & getName() const
Definition: HDF5Object.h:103
HDF5Object(const HDF5Object &that)
Copy constructor cannot be used.
HDF5Object()
Default constructor sets to invalid hid.
Definition: HDF5Object.h:74
virtual ~HDF5Object()
The destructor in a derived class should close the hid appropriately.
virtual void close()=0
Close the hid if valid.
void clearHid()
Clear the hid (set to invalid).
Definition: HDF5Object.h:116
static Bool hasHDF5Support()
Check if there is HDF5 support compiled in.
hid_t getHid() const
Get the hid.
Definition: HDF5Object.h:92
static void throwNoHDF5()
If no HDF5, throw an exception that HDF5 is not supported.
void setName(const String &name)
Get or set the name.
Definition: HDF5Object.h:101
void setHid(hid_t hid)
Set the hid.
Definition: HDF5Object.h:112
HDF5Object & operator=(const HDF5Object &that)
Assignment cannot be used.
bool isValid() const
Is it a valid hid?
Definition: HDF5Object.h:88
String: the storage and methods of handling collections of characters.
Definition: String.h:225
this file contains all the compiler specific defines
Definition: mainpage.dox:28
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42
unsigned long long uInt64
Definition: aipsxtype.h:39