# Copyright (C) 2014-2017 MongoDB, 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. module Mongo class Cluster module Topology # Defines behaviour for when a cluster is in single topology. # # @since 2.0.0 class Single include Monitoring::Publishable # The display name for the topology. # # @since 2.0.0 NAME = 'Single'.freeze # @return [ Hash ] options The options. attr_reader :options # @return [ String ] seed The seed address. attr_reader :seed # @return [ monitoring ] monitoring the monitoring. attr_reader :monitoring # Get the display name. # # @example Get the display name. # Single.display_name # # @return [ String ] The display name. # # @since 2.0.0 def display_name NAME end # Elect a primary server within this topology. # # @example Elect a primary server. # topology.elect_primary(description, servers) # # @param [ Server::Description ] description The description of the # elected primary. # @param [ Array ] servers The list of known servers to the # cluster. # # @return [ Single ] The topology. def elect_primary(description, servers); self; end # Determine if the topology would select a readable server for the # provided candidates and read preference. # # @example Is a readable server present? # topology.has_readable_server?(cluster, server_selector) # # @param [ Cluster ] cluster The cluster. # @param [ ServerSelector ] server_selector The server # selector. # # @return [ true ] A standalone always has a readable server. # # @since 2.4.0 def has_readable_server?(cluster, server_selector = nil); true; end # Determine if the topology would select a writable server for the # provided candidates. # # @example Is a writable server present? # topology.has_writable_server?(servers) # # @param [ Cluster ] cluster The cluster. # # @return [ true ] A standalone always has a writable server. # # @since 2.4.0 def has_writable_server?(cluster); true; end # Initialize the topology with the options. # # @example Initialize the topology. # Single.new(options) # # @param [ Hash ] options The options. # @param [ Monitoring ] monitoring The monitoring. # @param [ Array ] seeds The seeds. # # @since 2.0.0 def initialize(options, monitoring, seeds = []) @options = options @monitoring = monitoring @seed = seeds.first end # A single topology is not a replica set. # # @example Is the topology a replica set? # Single.replica_set? # # @return [ false ] Always false. # # @since 2.0.0 def replica_set?; false; end # Single topologies have no replica set name. # # @example Get the replica set name. # single.replica_set_name # # @return [ nil ] Always nil. # # @since 2.0.0 def replica_set_name; nil; end # Select appropriate servers for this topology. # # @example Select the servers. # Single.servers(servers, 'test') # # @param [ Array ] servers The known servers. # # @return [ Array ] The single servers. # # @since 2.0.0 def servers(servers, name = nil) [ servers.detect { |server| !server.unknown? } ] end # Whether a server description's hosts may be added to the cluster. # # @example Check if a description's hosts may be added to the cluster. # topology.add_hosts?(description, servers) # # @param [ Mongo::Server::Description ] description The description. # @param [ Array ] servers The cluster servers. # # @return [ false ] A description's hosts are never added to a # cluster of Single topology. # # @since 2.0.6 def add_hosts?(description, servers); false; end # Whether a description can be used to remove hosts from the cluster. # # @example Check if a description can be used to remove hosts from # the cluster. # topology.remove_hosts?(description) # # @param [ Mongo::Server::Description ] description The description. # # @return [ true ] A description can never be used to remove hosts # from a cluster of Single topology. # # @since 2.0.6 def remove_hosts?(description); false; end # Whether a specific server in the cluster can be removed, given a description. # # @example Check if a specific server can be removed from the cluster. # topology.remove_server?(description, server) # # @param [ Mongo::Server::Description ] description The description. # @param [ Mongo::Serve ] server The server in question. # # @return [ false ] A server is never removed from a cluster of Single topology. # # @since 2.0.6 def remove_server?(description, server); false; end # A single topology is not sharded. # # @example Is the topology sharded? # Single.sharded? # # @return [ false ] Always false. # # @since 2.0.0 def sharded?; false; end # A single topology is single. # # @example Is the topology single? # Single.single? # # @return [ true ] Always true. # # @since 2.0.0 def single?; true; end # An single topology is not unknown. # # @example Is the topology unknown? # Single.unknown? # # @return [ false ] Always false. # # @since 2.0.0 def unknown?; false; end # Notify the topology that a standalone was discovered. # # @example Notify the topology that a standalone was discovered. # topology.standalone_discovered # # @return [ Topology::Single ] Always returns self. # # @since 2.0.6 def standalone_discovered; self; end # Publish that a member of this topology was discovered. # # @example Publish that a member was discovered. # topology.member_discovered # # @since 2.4.0 def member_discovered publish_sdam_event( Monitoring::TOPOLOGY_CHANGED, Monitoring::Event::TopologyChanged.new(self, self) ) end end end end end