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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
#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(DB_NOSYNC); }
};
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;
if (!dt.get_data())
data = "";
else
data = string((char *) dt.get_data(), dt.get_size());
} catch (DbException e) { rethrow(e); }
return true;
}
bool queryListDB(const string & filename, const string & dbname,
const string & key, Strings & data)
{
string d;
if (!queryDB(filename, dbname, key, d))
return false;
string::iterator it = d.begin();
while (it != d.end()) {
if (it + 4 > d.end())
throw Error(format("short db entry: `%1%'") % d);
unsigned int len;
len = (unsigned char) *it++;
len |= ((unsigned char) *it++) << 8;
len |= ((unsigned char) *it++) << 16;
len |= ((unsigned char) *it++) << 24;
if (it + len > d.end())
throw Error(format("short db entry: `%1%'") % d);
string s;
while (len--) s += *it++;
data.push_back(s);
}
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 setListDB(const string & filename, const string & dbname,
const string & key, const Strings & data)
{
string d;
for (Strings::const_iterator it = data.begin();
it != data.end(); it++)
{
string s = *it;
unsigned int len = s.size();
d += len & 0xff;
d += (len >> 8) & 0xff;
d += (len >> 16) & 0xff;
d += (len >> 24) & 0xff;
d += s;
}
setDB(filename, dbname, key, d);
}
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,
Strings & keys)
{
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)
keys.push_back(
string((char *) kt.get_data(), kt.get_size()));
} catch (DbException e) { rethrow(e); }
}
|
