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/** @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"
namespace mongo {
extern const BSONObj reverseNaturalObj; // { $natural : -1 }
namespace repl {
/**
* Authenticates conn using the server's cluster-membership credentials.
*
* Returns true on successful authentication.
*/
bool replAuthenticate(DBClientBase* conn);
/* started abstracting out the querying of the primary/master's oplog
still fairly awkward but a start.
*/
class OplogReader {
shared_ptr<DBClientConnection> _conn;
shared_ptr<DBClientCursor> cursor;
int _tailingQueryOptions;
public:
OplogReader();
~OplogReader() { }
void resetCursor() { cursor.reset(); }
void resetConnection() {
cursor.reset();
_conn.reset();
}
DBClientConnection* conn() { return _conn.get(); }
BSONObj findOne(const char *ns, const Query& q) {
return conn()->findOne(ns, q, 0, QueryOption_SlaveOk);
}
BSONObj getLastOp(const char *ns) {
return findOne(ns, Query().sort(reverseNaturalObj));
}
/* SO_TIMEOUT (send/recv time out) for our DBClientConnections */
static const int tcp_timeout = 30;
/* ok to call if already connected */
bool connect(const std::string& hostname);
bool connect(const std::string& hostname, const OID& myRID);
bool connect(const mongo::OID& rid, const int from, const std::string& to);
void tailCheck();
bool haveCursor() { return cursor.get() != 0; }
/** this is ok but commented out as when used one should consider if QueryOption_OplogReplay
is needed; if not fine, but if so, need to change.
*//*
void query(const char *ns, const BSONObj& query) {
verify( !haveCursor() );
cursor.reset( _conn->query(ns, query, 0, 0, 0, QueryOption_SlaveOk).release() );
}*/
/** this can be used; it is commented out as it does not indicate
QueryOption_OplogReplay and that is likely important. could be uncommented
just need to add that.
*/
/*
void queryGTE(const char *ns, OpTime t) {
BSONObjBuilder q;
q.appendDate("$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(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); }
private:
/** @return true iff connection was successful */
bool commonConnect(const std::string& hostName);
bool passthroughHandshake(const mongo::OID& rid, const int f);
};
} // namespace repl
} // namespace mongo
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