Tree-M/MT/MTcursor.h

/*********************************************************************
*                                                                    *
* Copyright (c) 1997,1998, 1999                                      *
* Multimedia DB Group and DEIS - CSITE-CNR,                          *
* University of Bologna, Bologna, ITALY.                             *
*                                                                    *
* All Rights Reserved.                                               *
*                                                                    *
* Permission to use, copy, and distribute this software and its      *
* documentation for NON-COMMERCIAL purposes and without fee is       *
* hereby granted provided  that this copyright notice appears in     *
* all copies.                                                        *
*                                                                    *
* THE AUTHORS MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT THE        *
* SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING  *
* BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY,      *
* FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHOR  *
* SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A      *
* RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS    *
* DERIVATIVES.                                                       *
*                                                                    *
*********************************************************************/

#ifndef MTCURSOR_H
#define MTCURSOR_H

#ifndef MAXDOUBLE
#ifdef _WIN32   // for MAXDOUBLE
#include <float.h>
#define MAXDOUBLE DBL_MAX
#else
#include <values.h>
#endif
#endif
#include "GiST.h"
#include "list.h"

class MT;
class MTentry;
class MTpred;

class dst {     // this class is used in the NN-search algorithm for the priority queue
public:
        dst(): bound(0), d(MAXDOUBLE) {}
        dst(GiSTpath p, double LB, double dist): bound(LB), d(dist), path(p) {}

        double Bound() const { return bound; }
        double Dist() const { return d; }
        GiSTpath Path() { return path; }
private:
        double bound;
        double d;
        GiSTpath path;
};

int comparedst(dst *a, dst *b);
int comparedst(dst& a, dst& b);

class MTcursor {
public:
        MTcursor(const MT& tree, const MTpred& query);
        MTentry *Next();
        BOOL IsReady() const;
        double Bound() const;
        ~MTcursor();

private:
        void FetchNode();

        const MT& tree;
        list<MTentry *> results;
        list<dst *> queue;
        MTpred *query;
};

#endif
Revision:	1.2
Committed:	Fri Jul 27 12:48:23 2001 UTC (22 years, 9 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.1:	+1 -1 lines
Log Message:	* empty log message *
#	Content
1	/*********************************************************************
2	* *
3	* Copyright (c) 1997,1998, 1999 *
4	* Multimedia DB Group and DEIS - CSITE-CNR, *
5	* University of Bologna, Bologna, ITALY. *
6	* *
7	* All Rights Reserved. *
8	* *
9	* Permission to use, copy, and distribute this software and its *
10	* documentation for NON-COMMERCIAL purposes and without fee is *
11	* hereby granted provided that this copyright notice appears in *
12	* all copies. *
13	* *
14	* THE AUTHORS MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT THE *
15	* SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING *
16	* BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, *
17	* FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHOR *
18	* SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A *
19	* RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS *
20	* DERIVATIVES. *
21	* *
22	*********************************************************************/
23
24	#ifndef MTCURSOR_H
25	#define MTCURSOR_H
26
27	#ifndef MAXDOUBLE
28	#ifdef _WIN32 // for MAXDOUBLE
29	#include <float.h>
30	#define MAXDOUBLE DBL_MAX
31	#else
32	#include <values.h>
33	#endif
34	#endif
35	#include "GiST.h"
36	#include "list.h"
37
38	class MT;
39	class MTentry;
40	class MTpred;
41
42	class dst { // this class is used in the NN-search algorithm for the priority queue
43	public:
44	dst(): bound(0), d(MAXDOUBLE) {}
45	dst(GiSTpath p, double LB, double dist): bound(LB), d(dist), path(p) {}
46
47	double Bound() const { return bound; }
48	double Dist() const { return d; }
49	GiSTpath Path() { return path; }
50	private:
51	double bound;
52	double d;
53	GiSTpath path;
54	};
55
56	int comparedst(dst a, dst b);
57	int comparedst(dst& a, dst& b);
58
59	class MTcursor {
60	public:
61	MTcursor(const MT& tree, const MTpred& query);
62	MTentry *Next();
63	BOOL IsReady() const;
64	double Bound() const;
65	~MTcursor();
66
67	private:
68	void FetchNode();
69
70	const MT& tree;
71	list<MTentry *> results;
72	list<dst *> queue;
73	MTpred *query;
74	};
75
76	#endif