casacore
BaseSinkSource.h
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1//# BaseSinkSource.h: Shared base class for ByteSink and ByteSource
2//# Copyright (C) 1996,1999,2001
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_BASESINKSOURCE_H
29#define CASA_BASESINKSOURCE_H
30
31#include <casacore/casa/aips.h>
32#include <casacore/casa/IO/TypeIO.h>
33#include <casacore/casa/IO/ByteIO.h>
34#include <casacore/casa/Utilities/CountedPtr.h>
35
36namespace casacore { //# NAMESPACE CASACORE - BEGIN
37
38// <summary>Shared base class for ByteSink and ByteSource.</summary>
39
40// <use visibility=export>
41
42// <prerequisite>
43// <li> <linkto class=TypeIO>TypeIO</linkto> class and derived classes
44// </prerequisite>
45
46// <reviewed reviewer="Friso Olnon" date="1996/11/06" tests="tByteSink" demos="">
47// </reviewed>
48
49// <synopsis>
50// This class provides the common functionality for the classes
51// <linkto class=ByteSink>ByteSink</linkto> and
52// <linkto class=ByteSource>ByteSource</linkto>.
53// <p>
54// The object is constructed using a typed byte stream. This stream
55// is an instance of a class derived from class
56// <linkto class=TypeIO>TypeIO</linkto>. This makes it possible to
57// store the data in any format (e.g. CanonicalIO or RawIO).
58// Class <linkto class=CanonicalIO>CanonicalIO</linkto> makes it
59// possible to store the data in a canonical (machine-independent) format,
60// so it can be read on any machine and operating system. The canonical
61// format is big-endian IEEE, where a (unsigned) long is stored as 8 bytes.
62// This means that on common 32-bit big-endian machines like SUN and HP
63// only longs have to be converted and that CanonicalIO is as fast as RawIO.
64// Class <linkto class=RawIO>RawIO</linkto> stores the data in native
65// format, so the IO-process is faster on especially little-endian
66// machines (PC, DEC-alpha). Note that RawIO can also be used to read
67// bytes and interprete or convert them thereafter (e.g. using the
68// conversion functions in the <linkto class=Conversion>Conversion</linkto>
69// Conversion framework.
70// <p>
71// In its turn TypeIO uses an instance of a class derived from class
72// <linkto class=ByteIO>ByteIO</linkto>. This makes it possible to
73// use any output stream (e.g. file, memory).
74// </synopsis>
75
76// <motivation>
77// The design of the ByteSink and ByteSource classes resembles the design of
78// the iostream classes in the standard library. A shared base class is needed
79// to allow multiple inheritance needed for class ByteSinkSource.
80// </motivation>
81
82
84{
85public:
86 // This functions returns a reference to itsTypeIO.
87 // <group>
89 const TypeIO& typeIO() const;
90 // </group>
91
92 // This function sets the position on the given offset.
93 // The seek option defines from which position the seek is done.
94 // <group>
97 // </group>
98
99 // Is the SinkSource readable?
101
102 // Is the SinkSource writable?
104
105 // Is the SinkSource seekable?
107
108 // Is the BaseSinkSource unusable?
109 Bool isNull() const;
110
111protected:
113
114 // Construct using the given TypeIO. If takeOver is true the this class
115 // will delete the supplied pointer. Otherwise the caller is responsible
116 // for this.
118
119 // The copy constructor uses reference semantics
121
122 // The assignment operator uses reference semantics
124
126
127
128 // This variable keeps a pointer to a TypeIO.
130};
131
132
133
134} //# NAMESPACE CASACORE - END
135
136#endif
Bool isSeekable() const
Is the SinkSource seekable?
BaseSinkSource & operator=(const BaseSinkSource &BaseSinkSource)
The assignment operator uses reference semantics.
TypeIO & typeIO()
This functions returns a reference to itsTypeIO.
Bool isWritable() const
Is the SinkSource writable?
BaseSinkSource(const BaseSinkSource &BaseSinkSource)
The copy constructor uses reference semantics.
Bool isReadable() const
Is the SinkSource readable?
CountedPtr< TypeIO > itsTypeIO
This variable keeps a pointer to a TypeIO.
Int64 seek(Int offset, ByteIO::SeekOption=ByteIO::Begin)
Int64 seek(Int64 offset, ByteIO::SeekOption=ByteIO::Begin)
This function sets the position on the given offset.
BaseSinkSource(TypeIO *typeIO, Bool takeOver=False)
Construct using the given TypeIO.
const TypeIO & typeIO() const
Bool isNull() const
Is the BaseSinkSource unusable?
SeekOption
Define the possible seek options.
Definition: ByteIO.h:82
@ Begin
Seek from beginning of file.
Definition: ByteIO.h:84
Referenced counted pointer for constant data.
Definition: CountedPtr.h:81
this file contains all the compiler specific defines
Definition: mainpage.dox:28
const Bool False
Definition: aipstype.h:44
long long Int64
Define the extra non-standard types used by Casacore (like proposed uSize, Size)
Definition: aipsxtype.h:38
int Int
Definition: aipstype.h:50
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42