root/gsdl/trunk/lib/dbclass.h @ 15655

Revision 15655, 3.3 KB (checked in by mdewsnip, 11 years ago)

(Adding new DB support) Created default implementations of getinfo() and setinfo() in dbclass so they don't necessarily be re-implemented for every subclass.

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1/**********************************************************************
2 *
3 * dbclass.h --
4 * Copyright (C) 1999-2008  The New Zealand Digital Library Project
5 *
6 * A component of the Greenstone digital library software
7 * from the New Zealand Digital Library Project at the
8 * University of Waikato, New Zealand.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 *
24 *********************************************************************/
25
26#ifndef DBCLASS_H
27#define DBCLASS_H
28
29
30#include "text_t.h"
31#include "infodbclass.h"
32
33#if defined(GSDL_USE_OBJECTSPACE)
34#  include <ospace\std\iostream>
35#  include <ospace\std\fstream>
36#elif defined(GSDL_USE_IOS_H)
37#  include <iostream.h>
38#  include <fstream.h>
39#else
40#  include <iostream>
41#  include <fstream>
42#endif
43
44
45#define DB_READER         1
46#define DB_WRITER         2
47#define DB_WRITER_CREATE  3
48
49
50class dbclass
51{
52public:
53  dbclass() { logout = &cerr; }
54  virtual ~dbclass();
55
56  void setlogout (ostream *logout_arg) { logout = logout_arg; }
57
58
59  // -----------------------------------------------------------------------------------------------
60  // These functions MUST be implemented by subclasses, as they are database-specific
61
62  // returns true if opened
63  virtual bool opendatabase (const text_t &filename, int mode, int num_retrys, bool need_filelock) = 0;
64
65  virtual void closedatabase () = 0;
66
67  virtual void deletekey (const text_t &key) = 0;
68
69  // returns true on success
70  virtual bool getkeydata (const text_t& key, text_t &data) = 0;
71
72  // returns array of keys
73  virtual text_tarray getkeys () = 0;
74
75  // returns true on success
76  virtual bool setkeydata (const text_t &key, const text_t &data) = 0;
77
78
79  // -----------------------------------------------------------------------------------------------
80  // These functions may be overwritten by subclasses, but a default implementation is provided
81
82  // returns true if exists
83  virtual bool exists (const text_t& key);
84
85  // returns true on success
86  virtual bool getinfo (const text_t& key, infodbclass &info);
87
88  // returns true on success
89  virtual bool setinfo (const text_t &key, const infodbclass &info);
90
91
92  // replaces the .c, .p, .n, .l syntax (child, parent, next, previous)
93  // it expects child, parent, etc. to exist if syntax has been used
94  // so you should test before using
95  text_t translate_OID(const text_t &OID, infodbclass &info);
96
97protected:
98  ostream *logout;
99
100  // returns true on success
101  bool getinfoline (text_t::iterator &here, text_t::iterator end, text_t &key, text_t &value);
102
103  void get_first_child (text_t &OID, infodbclass &info);
104  void get_last_child (text_t &OID, infodbclass &info);
105  void get_next_sibling (text_t &OID, infodbclass &info);
106  void get_previous_sibling (text_t &OID, infodbclass &info);
107};
108
109
110#endif
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