member_state.h

/*
 *    Copyright (C) 2010 10gen Inc.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

#pragma once

#include <string>

namespace mongo {
namespace repl {


/*
    RS_STARTUP    serving still starting up, or still trying to initiate the set
    RS_PRIMARY    this server thinks it is primary
    RS_SECONDARY  this server thinks it is a secondary (slave mode)
    RS_RECOVERING recovering/resyncing; after recovery usually auto-transitions to secondary
    RS_STARTUP2   loaded config, still determining who is primary

    State -> integer mappings are reserved forever.  Do not change them or delete them, except
    to update RS_MAX when introducing new states.
*/
struct MemberState {
    enum MS {
        RS_STARTUP = 0,
        RS_PRIMARY = 1,
        RS_SECONDARY = 2,
        RS_RECOVERING = 3,
        RS_STARTUP2 = 5,
        RS_UNKNOWN = 6, /* remote node not yet reached */
        RS_ARBITER = 7,
        RS_DOWN = 8, /* node not reachable for a report */
        RS_ROLLBACK = 9,
        RS_REMOVED = 10, /* node removed from replica set */
        RS_MAX = 10
    } s;

    MemberState(MS ms = RS_UNKNOWN) : s(ms) {}
    explicit MemberState(int ms) : s((MS)ms) {}

    bool startup() const {
        return s == RS_STARTUP;
    }
    bool primary() const {
        return s == RS_PRIMARY;
    }
    bool secondary() const {
        return s == RS_SECONDARY;
    }
    bool recovering() const {
        return s == RS_RECOVERING;
    }
    bool startup2() const {
        return s == RS_STARTUP2;
    }
    bool rollback() const {
        return s == RS_ROLLBACK;
    }
    bool readable() const {
        return s == RS_PRIMARY || s == RS_SECONDARY;
    }
    bool removed() const {
        return s == RS_REMOVED;
    }
    bool arbiter() const {
        return s == RS_ARBITER;
    }

    std::string toString() const;

    bool operator==(const MemberState& r) const {
        return s == r.s;
    }
    bool operator!=(const MemberState& r) const {
        return s != r.s;
    }
};

inline std::string MemberState::toString() const {
    switch (s) {
        case RS_STARTUP:
            return "STARTUP";
        case RS_PRIMARY:
            return "PRIMARY";
        case RS_SECONDARY:
            return "SECONDARY";
        case RS_RECOVERING:
            return "RECOVERING";
        case RS_STARTUP2:
            return "STARTUP2";
        case RS_ARBITER:
            return "ARBITER";
        case RS_DOWN:
            return "DOWN";
        case RS_ROLLBACK:
            return "ROLLBACK";
        case RS_UNKNOWN:
            return "UNKNOWN";
        case RS_REMOVED:
            return "REMOVED";
    }
    return "";
}

}  // namespace repl
}  // namespace mongo