casacore
LatticeBase.h
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1 //# LatticeBase.h: A non-templated, abstract base class for array-like classes
2 //# Copyright (C) 1999,2000,2003
3 //# Associated Universities, Inc. Washington DC, USA.
4 //#
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26 //# $Id$
27 
28 #ifndef LATTICES_LATTICEBASE_H
29 #define LATTICES_LATTICEBASE_H
30 
31 
32 //# Includes
33 #include <casacore/casa/aips.h>
34 #include <casacore/lattices/LEL/LELCoordinates.h>
35 #include <casacore/casa/Arrays/IPosition.h>
36 #include <casacore/casa/Utilities/DataType.h>
37 #include <casacore/casa/IO/FileLocker.h>
38 #include <casacore/casa/BasicSL/String.h>
39 
40 namespace casacore { //# NAMESPACE CASACORE - BEGIN
41 
42 //# Forward Declarations
43 class LogIO;
44 
45 
46 // <summary>
47 // A non-templated, abstract base class for array-like objects.
48 // </summary>
49 
50 // <use visibility=export>
51 
52 // <reviewed reviewer="Bob Garwood" date="2000/01/18" tests="tArrayLattice.cc" demos="dLattice.cc">
53 // </reviewed>
54 
55 // <synopsis>
56 // This pure abstract base class defines the operations which may be
57 // performed on a lattice of any type.
58 // <br>See class <linkto class=Lattice>Lattice</linkto> for a detailed
59 // description of a lattice.
60 // </synopsis>
61 
62 // <motivation>
63 // It is very useful to be able to keep a pointer to a
64 // non-templated base class. Furthermore it gives the opportunity to
65 // factor out some non-templated code.
66 // </motivation>
67 
68 // <note>
69 // The cache functions (maximumCacheSize, setMaximumCacheSize,
70 // setCacheSizeInTiles, setCacheSizeFromPath, clearCache, and
71 // showCacheStatistics) should all be over-ridden together as
72 // in PagedArray.
73 // </note>
74 //
75 //# <todo asof="1999/02/04">
76 //# <li>
77 //# </todo>
78 
79 
81 {
82 public:
83  // A virtual destructor is needed so that it will use the actual destructor
84  // in the derived class.
85  virtual ~LatticeBase();
86 
87  // Make a copy of the derived object (reference semantics).
88  virtual LatticeBase* clone() const = 0;
89 
90  // Get the image type (returns name of derived class).
91  // The default implementation returns "Lattice".
92  // Note it is made pure virtual in ImageInterface.
93  virtual String imageType() const;
94 
95  // Get the data type of the lattice.
96  virtual DataType dataType() const = 0;
97 
98  // Is the lattice persistent and can it be loaded by other processes as well?
99  // That is the case for a PagedArray or PagedImage and for an ImageExpr
100  // which does not use transient lattices or regions.
101  // <br>The default implementation returns False.
102  virtual Bool isPersistent() const;
103 
104  // Is the lattice paged to disk?
105  // <br>The default implementation returns False.
106  virtual Bool isPaged() const;
107 
108  // Can the lattice data be referenced as an array section?
109  // That is the case for an ArrayLattice or a Temp/SubLattice using it.
110  // It is used by LatticeIterInterface.
111  // <br>The default implementation returns False.
112  virtual Bool canReferenceArray() const;
113 
114  // Is the lattice writable?
115  // <br>The default implementation returns True.
116  virtual Bool isWritable() const;
117 
118  // Save the image in an AipsIO file with the given name.
119  // Its purpose is to make ImageConcat and ImageExpr objects
120  // persistent.
121  // <br>The default implementation throws an exception.
122  virtual void save (const String& fileName) const;
123 
124  // It is strongly recommended to use class
125  // <linkto class=LatticeLocker>LatticeLocker</linkto> to
126  // handle lattice locking. It also contains a more detailed
127  // explanation of the locking process.
128  // <br>By default the functions do not do anything at all.
129  // lock() and hasLock return True, which is suitable for all
130  // non-paged lattices.
131  // <group>
132  virtual Bool lock (FileLocker::LockType, uInt nattempts);
133  virtual void unlock();
135  // </group>
136 
137  // Resynchronize the Lattice object with the lattice file.
138  // This function is only useful if no read-locking is used, ie.
139  // if the table lock option is UserNoReadLocking or AutoNoReadLocking.
140  // In that cases the table system does not acquire a read-lock, thus
141  // does not synchronize itself automatically.
142  // <br>By default the function does not do anything at all.
143  virtual void resync();
144 
145  // Flush the data (but do not unlock).
146  // <br>By default the function does not do anything at all.
147  virtual void flush();
148 
149  // Temporarily close the lattice.
150  // It will be reopened automatically on the next access.
151  // <br>By default the function does not do anything at all.
152  virtual void tempClose();
153 
154  // Explicitly reopen the temporarily closed lattice.
155  // <br>By default the function does not do anything at all.
156  virtual void reopen();
157 
158  // Return the name of the current Lattice object. This will generally
159  // be a file name for lattices that have a persistent form. Any path
160  // before the actual file name can be optionally stripped off.
161  // <br>The default implementation returns an empty string.
162  virtual String name (Bool stripPath=False) const;
163 
164  // Return the shape of the Lattice including all degenerate axes
165  // (ie. axes with a length of one)
166  virtual IPosition shape() const = 0;
167 
168  // Return the number of axes in this Lattice. This includes all
169  // degenerate axes.
170  // <br>The default implementation returns shape().nelements().
171  virtual uInt ndim() const;
172 
173  // Return the total number of elements in this Lattice.
174  // <br>The default implementation returns shape().product().
175  // <group>
176  virtual size_t nelements() const;
177  size_t size() const
178  { return nelements(); }
179  // </group>
180 
181  // Return a value of "True" if this instance of Lattice and 'other' have
182  // the same shape, otherwise returns a value of "False".
183  Bool conform (const LatticeBase& other) const
184  { return shape().isEqual (other.shape()); }
185 
186  // Return the coordinates of the lattice.
187  // <br>The default implementation returns an 'empty' LELLattCoord object.
189 
190  // This function returns the recommended maximum number of pixels to
191  // include in the cursor of an iterator. The Lattice class has a default
192  // implementation which returns a number that is a power of two and
193  // includes enough pixels to consume between 4 and 8 MBytes of memory.
194  virtual uInt advisedMaxPixels() const = 0;
195 
196  // Returns a recommended cursor shape for iterating through all the pixels
197  // in the Lattice. The default implementation sets up a shape that
198  // completely fills as many axes as possible, but always at least the
199  // first axis. For example, given a 10x20x30 Lattice
200  // <srcblock>
201  // maxPixels = 1 --> niceCursorShape = [10,1,1]
202  // 100 --> niceCursorShape = [10,1,1]
203  // 300 --> niceCursorShape = [10,20,1]
204  // 10000 --> niceCursorShape = [10,20,30]
205  // </srcblock>
206  // The default argument is the result of <src>advisedMaxPixels()</src>.
207  // <group>
208  IPosition niceCursorShape (uInt maxPixels) const
209  { return doNiceCursorShape (maxPixels); }
211  { return doNiceCursorShape (advisedMaxPixels()); }
212  // </group>
213 
214  // Check class internals - used for debugging. Should always return True
215  virtual Bool ok() const;
216 
217  // The function (in the derived classes) doing the actual work.
218  // This function is public, so it can be used internally in the
219  // various Lattice classes.
220  // <br>The default implementation tries to fit as many axes
221  // as possible given <src>maxPixels</src>.
222  virtual IPosition doNiceCursorShape (uInt maxPixels) const;
223 
224  // Maximum cache size - not necessarily all used. In pixels.
225  // Default returns 0, which means that there is no maximum.
226  virtual uInt maximumCacheSize() const;
227 
228  // Set the maximum (allowed) cache size as indicated.
229  // <br>The default implementation does nothing.
230  virtual void setMaximumCacheSize (uInt howManyPixels);
231 
232  // Set the actual cache size for this Array to be big enough for the
233  // indicated number of tiles. This cache is not shared with PagedArrays
234  // in other rows and is always clipped to be less than the maximum value
235  // set using the setMaximumCacheSize member function.
236  // Tiles are cached using a first in first out algorithm.
237  // <br>The default implementation does nothing.
238  virtual void setCacheSizeInTiles (uInt howManyTiles);
239 
240  // Set the cache size as to "fit" the indicated path.
241  // <br>The default implementation does nothing.
242  virtual void setCacheSizeFromPath (const IPosition& sliceShape,
243  const IPosition& windowStart,
244  const IPosition& windowLength,
245  const IPosition& axisPath);
246 
247  // Clears and frees up the caches, but the maximum allowed cache size is
248  // unchanged from when setCacheSize was called.
249  // <br>The default implementation does nothing.
250  virtual void clearCache();
251 
252  // Report on cache success.
253  // <br>The default implementation does nothing.
254  virtual void showCacheStatistics (ostream& os) const;
255 
256 
257 protected:
258  // Define default constructor to be used by derived classes.
260 
261  // Copy constructor and assignment can only be used by derived classes.
262  // <group>
265  { return *this; }
266  // </group>
267 
268  // Throw an exception for arithmetic on a Bool Lattice.
269  void throwBoolMath() const;
270 };
271 
272 
273 
274 } //# NAMESPACE CASACORE - END
275 
276 #endif
LockType
Define the possible lock types.
Definition: FileLocker.h:95
bool isEqual(const IPosition &other) const
Element-by-element comparison for equality.
virtual Bool isPersistent() const
Is the lattice persistent and can it be loaded by other processes as well? That is the case for a Pag...
virtual uInt maximumCacheSize() const
Maximum cache size - not necessarily all used.
virtual String imageType() const
Get the image type (returns name of derived class).
Bool conform(const LatticeBase &other) const
Return a value of "True" if this instance of Lattice and 'other' have the same shape,...
Definition: LatticeBase.h:183
virtual IPosition shape() const =0
Return the shape of the Lattice including all degenerate axes (ie.
size_t size() const
Definition: LatticeBase.h:177
virtual Bool isPaged() const
Is the lattice paged to disk? The default implementation returns False.
IPosition niceCursorShape(uInt maxPixels) const
Returns a recommended cursor shape for iterating through all the pixels in the Lattice.
Definition: LatticeBase.h:208
virtual Bool canReferenceArray() const
Can the lattice data be referenced as an array section? That is the case for an ArrayLattice or a Tem...
virtual Bool lock(FileLocker::LockType, uInt nattempts)
It is strongly recommended to use class LatticeLocker to handle lattice locking.
virtual void resync()
Resynchronize the Lattice object with the lattice file.
virtual uInt advisedMaxPixels() const =0
This function returns the recommended maximum number of pixels to include in the cursor of an iterato...
virtual void flush()
Flush the data (but do not unlock).
IPosition niceCursorShape() const
Definition: LatticeBase.h:210
virtual void setCacheSizeInTiles(uInt howManyTiles)
Set the actual cache size for this Array to be big enough for the indicated number of tiles.
virtual size_t nelements() const
Return the total number of elements in this Lattice.
LatticeBase()
Define default constructor to be used by derived classes.
Definition: LatticeBase.h:259
virtual uInt ndim() const
Return the number of axes in this Lattice.
virtual void showCacheStatistics(ostream &os) const
Report on cache success.
virtual void unlock()
void throwBoolMath() const
Throw an exception for arithmetic on a Bool Lattice.
LatticeBase & operator=(const LatticeBase &)
Definition: LatticeBase.h:264
LatticeBase(const LatticeBase &)
Copy constructor and assignment can only be used by derived classes.
Definition: LatticeBase.h:263
virtual LatticeBase * clone() const =0
Make a copy of the derived object (reference semantics).
virtual void tempClose()
Temporarily close the lattice.
virtual LELCoordinates lelCoordinates() const
Return the coordinates of the lattice.
virtual void reopen()
Explicitly reopen the temporarily closed lattice.
virtual ~LatticeBase()
A virtual destructor is needed so that it will use the actual destructor in the derived class.
virtual Bool hasLock(FileLocker::LockType) const
virtual Bool isWritable() const
Is the lattice writable? The default implementation returns True.
virtual IPosition doNiceCursorShape(uInt maxPixels) const
The function (in the derived classes) doing the actual work.
virtual void clearCache()
Clears and frees up the caches, but the maximum allowed cache size is unchanged from when setCacheSiz...
virtual void setCacheSizeFromPath(const IPosition &sliceShape, const IPosition &windowStart, const IPosition &windowLength, const IPosition &axisPath)
Set the cache size as to "fit" the indicated path.
virtual Bool ok() const
Check class internals - used for debugging.
virtual void setMaximumCacheSize(uInt howManyPixels)
Set the maximum (allowed) cache size as indicated.
virtual String name(Bool stripPath=False) const
Return the name of the current Lattice object.
virtual void save(const String &fileName) const
Save the image in an AipsIO file with the given name.
virtual DataType dataType() const =0
Get the data type of the lattice.
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
const Bool False
Definition: aipstype.h:44
unsigned int uInt
Definition: aipstype.h:51
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42