C++ Shard::ok方法代码示例

    // Deprecated, will move to the strategy itself
    Shard Request::primaryShard() const {
        assert( _didInit );

        if ( _chunkManager ) {
            if ( _chunkManager->numChunks() > 1 )
                throw UserException( 8060 , "can't call primaryShard on a sharded collection" );
            return _chunkManager->findChunk( _chunkManager->getShardKey().globalMin() )->getShard();
        }
        Shard s = _config->getShard( getns() );
        uassert( 10194 ,  "can't call primaryShard on a sharded collection!" , s.ok() );
        return s;
    }

    /**
     * Special internal logic to run reduced version handshake for empty namespace operations to
     * shards.
     *
     * Eventually this should go completely away, but for now many commands rely on unversioned but
     * mongos-specific behavior on mongod (auditing and replication information in commands)
     */
    static bool initShardVersionEmptyNS(DBClientBase * conn_in) {

        bool ok;
        BSONObj result;
        DBClientBase* conn = NULL;
        try {
            // May throw if replica set primary is down
            conn = getVersionable( conn_in );
            dassert( conn ); // errors thrown above

            // Check to see if we've already initialized this connection
            if (connectionShardStatus.hasAnySequenceSet(conn))
                return false;

            // Check to see if this is actually a shard and not a single config server
            // NOTE: Config servers are registered only by the name "config" in the shard cache, not
            // by host, so lookup by host will fail unless the host is also a shard.
            Shard shard = Shard::findIfExists(conn->getServerAddress());
            if (!shard.ok())
                return false;

            LOG(1) << "initializing shard connection to " << shard.toString() << endl;

            ok = setShardVersion(*conn,
                                 "",
                                 configServer.modelServer(),
                                 ChunkVersion(),
                                 NULL,
                                 true,
                                 result);
        }
        catch( const DBException& ) {

            // NOTE: Replica sets may fail to initShardVersion because future calls relying on
            // correct versioning must later call checkShardVersion on the primary.
            // Secondary queries and commands may not call checkShardVersion, but secondary ops
            // aren't versioned at all.
            if ( conn_in->type() != ConnectionString::SET ) {
                throw;
            }

            // NOTE: Only old-style cluster operations will talk via DBClientReplicaSets - using
            // checkShardVersion is required (which includes initShardVersion information) if these
            // connections are used.

            OCCASIONALLY {
                warning() << "failed to initialize new replica set connection version, "
                          << "will initialize on first use" << endl;
            }

            return false;
        }

        // Record the connection wire version if sent in the response, initShardVersion is a
        // handshake for mongos->mongod connections.
        if ( !result["minWireVersion"].eoo() ) {

            int minWireVersion = result["minWireVersion"].numberInt();
            int maxWireVersion = result["maxWireVersion"].numberInt();
            conn->setWireVersions( minWireVersion, maxWireVersion );
        }

        LOG(3) << "initial sharding result : " << result << endl;

        connectionShardStatus.setSequence(conn, "", 0);
        return ok;
    }