SERVER-13645 move Consensus class into its own header and cpp file

1 files changed, 82 insertions, 0 deletions

diff --git a/src/mongo/db/repl/consensus.h b/src/mongo/db/repl/consensus.h
new file mode 100644
index 00000000000..1d7b2cfdda6
--- /dev/null
+++ b/src/mongo/db/repl/consensus.h
@@ -0,0 +1,82 @@
+/**
+*    Copyright (C) 2008 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/util/concurrency/value.h"
+
+namespace mongo {
+
+    class ReplSetImpl;
+    struct Target;
+
+    class Consensus {
+    private:
+        ReplSetImpl &rs;
+        struct LastYea {
+            LastYea() : when(0), who(0xffffffff) { }
+            time_t when;
+            unsigned who;
+        };
+        static SimpleMutex lyMutex;
+        Guarded<LastYea,lyMutex> ly;
+        unsigned yea(unsigned memberId); // throws VoteException
+        void electionFailed(unsigned meid);
+        void _electSelf();
+        bool weAreFreshest(bool& allUp, int& nTies);
+        bool sleptLast; // slept last elect() pass
+
+        // This is a unique id that is changed each time we transition to PRIMARY, as the
+        // result of an election.
+        OID _electionId;
+        // PRIMARY server's time when the election to primary occurred
+        OpTime _electionTime;
+    public:
+        Consensus(ReplSetImpl *t) : rs(*t) {
+            sleptLast = false;
+            steppedDown = 0;
+        }
+
+        /* if we've stepped down, this is when we are allowed to try to elect ourself again.
+           todo: handle possible weirdnesses at clock skews etc.
+        */
+        time_t steppedDown;
+
+        int totalVotes() const;
+        bool aMajoritySeemsToBeUp() const;
+        bool shouldRelinquish() const;
+        void electSelf();
+        void electCmdReceived(BSONObj, BSONObjBuilder*);
+        void multiCommand(BSONObj cmd, list<Target>& L);
+
+        OID getElectionId() const { return _electionId; }
+        void setElectionId(OID oid) { _electionId = oid; }
+        OpTime getElectionTime() const { return _electionTime; }
+        void setElectionTime(OpTime electionTime) { _electionTime = electionTime; }
+    };
+} // namespace mongo