1 files changed, 120 insertions, 0 deletions
diff --git a/src/mongo/db/repl/topology_coordinator.h b/src/mongo/db/repl/topology_coordinator.h
new file mode 100644
index 00000000000..c384b27b8d5
--- /dev/null
+++ b/src/mongo/db/repl/topology_coordinator.h
@@ -0,0 +1,120 @@
+/**
+ *    Copyright (C) 2014 MongoDB 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 <string>
+
+#include "mongo/base/disallow_copying.h"
+#include "mongo/util/net/hostandport.h"
+
+namespace mongo {
+
+    class OpTime;
+
+namespace replset {
+
+    class HeartbeatInfo;
+    class Member;
+    struct MemberState;
+
+    typedef int Callback_t; // TBD
+
+
+    /**
+     * Replication Topology Coordinator interface.
+     *
+     * This object is responsible for managing the topology of the cluster.
+     * Tasks include consensus and leader election, chaining, and configuration management.
+     * Methods of this class should be non-blocking.
+     */
+
+
+    class TopologyCoordinator {
+        MONGO_DISALLOW_COPYING(TopologyCoordinator);
+    public:
+        virtual ~TopologyCoordinator() {}
+        
+        // The optime of the last op actually applied to the data
+        virtual void setLastApplied(const OpTime& optime) = 0;
+        // The optime of the last op marked as committed by the leader
+        virtual void setCommitOkayThrough(const OpTime& optime) = 0;
+        // The optime of the last op received over the network from the sync source
+        virtual void setLastReceived(const OpTime& optime) = 0;
+
+        // The amount of time this node delays applying ops when acting as a secondary
+        virtual int getSelfSlaveDelay() const = 0;
+        // Flag determining if chaining secondaries is allowed
+        virtual bool getChainingAllowedFlag() const = 0;
+
+        // For use with w:majority write concern
+        virtual int getMajorityNumber() const = 0;
+
+        // ReplCoord needs to know the state to implement certain public functions
+        virtual MemberState getMemberState() const = 0;
+
+        // Looks up _syncSource's address and returns it, for use by the Applier
+        virtual HostAndPort getSyncSourceAddress() const = 0;
+        // Chooses and sets a new sync source, based on our current knowledge of the world
+        virtual void chooseNewSyncSource() = 0; // this is basically getMemberToSyncTo()
+        // Do not choose a member as a sync source for a while; 
+        // call this when we have reason to believe it's a bad choice (do we need this?)
+        // (currently handled by _veto in rs_initialsync)
+        virtual void blacklistSyncSource(Member* member) = 0;
+
+        // Add function pointer to callback list; call function when config changes
+        // Applier needs to know when things like chainingAllowed or slaveDelay change. 
+        // ReplCoord needs to know when things like the tag sets change.
+        virtual void registerConfigChangeCallback(Callback_t) = 0;
+
+        // Applier calls this to notify that it's now safe to transition from SECONDARY to PRIMARY
+        virtual void signalDrainComplete() = 0;
+
+        // election entry point
+        virtual void electSelf() = 0;
+
+        // produce a reply to a RAFT-style RequestVote RPC
+        virtual bool prepareRequestVoteResponse(const BSONObj& cmdObj, 
+                                                std::string& errmsg, 
+                                                BSONObjBuilder& result) = 0; 
+
+        // produce a reply to a received electCmd
+        virtual void prepareElectCmdResponse(const BSONObj& cmdObj, BSONObjBuilder& result) = 0;
+
+        // produce a reply to a heartbeat
+        virtual bool prepareHeartbeatResponse(const BSONObj& cmdObj, 
+                                              std::string& errmsg, 
+                                              BSONObjBuilder& result) = 0;
+
+        // update internal state with heartbeat response
+        virtual void updateHeartbeatInfo(const HeartbeatInfo& newInfo) = 0;
+    protected:
+        TopologyCoordinator() {}
+    };
+} // namespace replset
+} // namespace mongo