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
|
/** @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/db/dbhelpers.h"
namespace mongo {
/* started abstracting out the querying of the primary/master's oplog
still fairly awkward but a start.
*/
class OplogReader {
shared_ptr<DBClientConnection> _conn;
shared_ptr<DBClientCursor> cursor;
int _tailingQueryOptions;
public:
OplogReader();
~OplogReader() { }
void resetCursor() { cursor.reset(); }
void resetConnection() {
cursor.reset();
_conn.reset();
}
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 std::string& hostname);
bool connect(const std::string& hostname, const BSONObj& me);
bool connect(const mongo::OID& rid, const int from, const string& to);
void tailCheck() {
if( cursor.get() && cursor->isDead() ) {
log() << "repl: old cursor isDead, will initiate a new one" << endl;
resetCursor();
}
}
bool haveCursor() { return cursor.get() != 0; }
/** this is ok but commented out as when used one should consider if QueryOption_OplogReplay
is needed; if not fine, but if so, need to change.
*//*
void query(const char *ns, const BSONObj& query) {
verify( !haveCursor() );
cursor.reset( _conn->query(ns, query, 0, 0, 0, QueryOption_SlaveOk).release() );
}*/
/** this can be used; it is commented out as it does not indicate
QueryOption_OplogReplay and that is likely important. could be uncommented
just need to add that.
*/
/*
void queryGTE(const char *ns, OpTime t) {
BSONObjBuilder q;
q.appendDate("$gte", t.asDate());
BSONObjBuilder q2;
q2.append("ts", q.done());
query(ns, q2.done());
}
*/
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();
}
/* old mongod's can't do the await flag... */
bool awaitCapable() {
return cursor->hasResultFlag(ResultFlag_AwaitCapable);
}
int getTailingQueryOptions() const { return _tailingQueryOptions; }
void setTailingQueryOptions( int tailingQueryOptions ) { _tailingQueryOptions = tailingQueryOptions; }
void peek(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); }
private:
/** @return true iff connection was successful */
bool commonConnect(const string& hostName);
bool passthroughHandshake(const mongo::OID& rid, const int f);
};
}
|
