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
|
#include "db.hh"
#include "util.hh"
#include <memory>
#include <db_cxx.h>
/* Wrapper classes that ensures that the database is closed upon
object destruction. */
class Db2 : public Db
{
public:
Db2(DbEnv *env, u_int32_t flags) : Db(env, flags) { }
~Db2() { close(0); }
};
class DbcClose
{
Dbc * cursor;
public:
DbcClose(Dbc * c) : cursor(c) { }
~DbcClose() { cursor->close(); }
};
static auto_ptr<Db2> openDB(const string & filename, const string & dbname,
bool readonly)
{
auto_ptr<Db2> db(new Db2(0, 0));
db->open(filename.c_str(), dbname.c_str(),
DB_HASH, readonly ? DB_RDONLY : DB_CREATE, 0666);
return db;
}
static void rethrow(DbException & e)
{
throw Error(e.what());
}
void createDB(const string & filename, const string & dbname)
{
try {
openDB(filename, dbname, false);
} catch (DbException e) { rethrow(e); }
}
bool queryDB(const string & filename, const string & dbname,
const string & key, string & data)
{
try {
int err;
auto_ptr<Db2> db = openDB(filename, dbname, true);
Dbt kt((void *) key.c_str(), key.length());
Dbt dt;
err = db->get(0, &kt, &dt, 0);
if (err) return false;
data = string((char *) dt.get_data(), dt.get_size());
} catch (DbException e) { rethrow(e); }
return true;
}
void setDB(const string & filename, const string & dbname,
const string & key, const string & data)
{
try {
auto_ptr<Db2> db = openDB(filename, dbname, false);
Dbt kt((void *) key.c_str(), key.length());
Dbt dt((void *) data.c_str(), data.length());
db->put(0, &kt, &dt, 0);
} catch (DbException e) { rethrow(e); }
}
void delDB(const string & filename, const string & dbname,
const string & key)
{
try {
auto_ptr<Db2> db = openDB(filename, dbname, false);
Dbt kt((void *) key.c_str(), key.length());
db->del(0, &kt, 0);
} catch (DbException e) { rethrow(e); }
}
void enumDB(const string & filename, const string & dbname,
DBPairs & contents)
{
try {
auto_ptr<Db2> db = openDB(filename, dbname, true);
Dbc * cursor;
db->cursor(0, &cursor, 0);
DbcClose cursorCloser(cursor);
Dbt kt, dt;
while (cursor->get(&kt, &dt, DB_NEXT) != DB_NOTFOUND) {
string key((char *) kt.get_data(), kt.get_size());
string data((char *) dt.get_data(), dt.get_size());
contents.push_back(DBPair(key, data));
}
} catch (DbException e) { rethrow(e); }
}
|
