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
|
/** @file oplogreader.h */
/**
* Copyright (C) 2012 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/client/constants.h"
#include "mongo/client/dbclientcursor.h"
#include "mongo/util/net/hostandport.h"
namespace mongo {
extern const BSONObj reverseNaturalObj; // { $natural : -1 }
namespace repl {
class ReplicationCoordinator;
/**
* Authenticates conn using the server's cluster-membership credentials.
*
* Returns true on successful authentication.
*/
bool replAuthenticate(DBClientBase* conn);
/* started abstracting out the querying of the primary/master's oplog
still fairly awkward but a start.
*/
class OplogReader {
private:
shared_ptr<DBClientConnection> _conn;
shared_ptr<DBClientCursor> cursor;
int _tailingQueryOptions;
// If _conn was actively connected, _host represents the current HostAndPort of the
// connection.
HostAndPort _host;
public:
OplogReader();
~OplogReader() { }
void resetCursor() { cursor.reset(); }
void resetConnection() {
cursor.reset();
_conn.reset();
_host = HostAndPort();
}
DBClientConnection* conn() { return _conn.get(); }
BSONObj findOne(const char *ns, const Query& q) {
return conn()->findOne(ns, q, 0, QueryOption_SlaveOk);
}
BSONObj getLastOp(const char *ns) {
return findOne(ns, Query().sort(reverseNaturalObj));
}
/* SO_TIMEOUT (send/recv time out) for our DBClientConnections */
static const int tcp_timeout = 30;
/* ok to call if already connected */
bool connect(const HostAndPort& host);
void tailCheck();
bool haveCursor() { return cursor.get() != 0; }
void query(const char *ns,
Query query,
int nToReturn,
int nToSkip,
const BSONObj* fields=0);
void tailingQuery(const char *ns, const BSONObj& query, const BSONObj* fields=0);
void tailingQueryGTE(const char *ns, OpTime t, const BSONObj* fields=0);
/* Do a tailing query, but only send the ts field back. */
void ghostQueryGTE(const char *ns, OpTime t) {
const BSONObj fields = BSON("ts" << 1 << "_id" << 0);
return tailingQueryGTE(ns, t, &fields);
}
bool more() {
uassert( 15910, "Doesn't have cursor for reading oplog", cursor.get() );
return cursor->more();
}
bool moreInCurrentBatch() {
uassert( 15911, "Doesn't have cursor for reading oplog", cursor.get() );
return cursor->moreInCurrentBatch();
}
int currentBatchMessageSize() {
if( NULL == cursor->getMessage() )
return 0;
return cursor->getMessage()->size();
}
int getTailingQueryOptions() const { return _tailingQueryOptions; }
void setTailingQueryOptions( int tailingQueryOptions ) { _tailingQueryOptions = tailingQueryOptions; }
void peek(std::vector<BSONObj>& v, int n) {
if( cursor.get() )
cursor->peek(v,n);
}
BSONObj nextSafe() { return cursor->nextSafe(); }
BSONObj next() { return cursor->next(); }
void putBack(BSONObj op) { cursor->putBack(op); }
HostAndPort getHost() const;
/**
* Connects this OplogReader to a valid sync source, using the provided lastOpTimeFetched
* and ReplicationCoordinator objects.
* If this function fails to connect to a sync source that is viable, this OplogReader
* is left unconnected, where this->conn() equals NULL.
* In the process of connecting, this function may add items to the repl coordinator's
* sync source blacklist.
* This function may throw DB exceptions.
*/
void connectToSyncSource(OperationContext* txn,
OpTime lastOpTimeFetched,
ReplicationCoordinator* replCoord);
};
} // namespace repl
} // namespace mongo
|
