1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2002
* Sleepycat Software. All rights reserved.
*
* $Id: AccessExample.cpp,v 11.18 2002/01/23 15:33:20 bostic Exp $
*/
#include <sys/types.h>
#include <iostream>
#include <iomanip>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <db_cxx.h>
using std::cin;
using std::cout;
using std::cerr;
class AccessExample
{
public:
AccessExample();
void run();
private:
static const char FileName[];
// no need for copy and assignment
AccessExample(const AccessExample &);
void operator = (const AccessExample &);
};
int main()
{
// Use a try block just to report any errors.
// An alternate approach to using exceptions is to
// use error models (see DbEnv::set_error_model()) so
// that error codes are returned for all Berkeley DB methods.
//
try {
AccessExample app;
app.run();
return (EXIT_SUCCESS);
}
catch (DbException &dbe) {
cerr << "AccessExample: " << dbe.what() << "\n";
return (EXIT_FAILURE);
}
}
const char AccessExample::FileName[] = "access.db";
AccessExample::AccessExample()
{
}
void AccessExample::run()
{
// Remove the previous database.
(void)remove(FileName);
// Create the database object.
// There is no environment for this simple example.
Db db(0, 0);
db.set_error_stream(&cerr);
db.set_errpfx("AccessExample");
db.set_pagesize(1024); /* Page size: 1K. */
db.set_cachesize(0, 32 * 1024, 0);
db.open(NULL, FileName, NULL, DB_BTREE, DB_CREATE, 0664);
//
// Insert records into the database, where the key is the user
// input and the data is the user input in reverse order.
//
char buf[1024];
char rbuf[1024];
char *t;
char *p;
int ret;
int len;
for (;;) {
cout << "input> ";
cout.flush();
cin.getline(buf, sizeof(buf));
if (cin.eof())
break;
if ((len = strlen(buf)) <= 0)
continue;
for (t = rbuf, p = buf + (len - 1); p >= buf;)
*t++ = *p--;
*t++ = '\0';
Dbt key(buf, len + 1);
Dbt data(rbuf, len + 1);
ret = db.put(0, &key, &data, DB_NOOVERWRITE);
if (ret == DB_KEYEXIST) {
cout << "Key " << buf << " already exists.\n";
}
}
cout << "\n";
// We put a try block around this section of code
// to ensure that our database is properly closed
// in the event of an error.
//
try {
// Acquire a cursor for the table.
Dbc *dbcp;
db.cursor(NULL, &dbcp, 0);
// Walk through the table, printing the key/data pairs.
Dbt key;
Dbt data;
while (dbcp->get(&key, &data, DB_NEXT) == 0) {
char *key_string = (char *)key.get_data();
char *data_string = (char *)data.get_data();
cout << key_string << " : " << data_string << "\n";
}
dbcp->close();
}
catch (DbException &dbe) {
cerr << "AccessExample: " << dbe.what() << "\n";
}
db.close(0);
}
|
