module Mongo::Cluster::Topology

Defines behavior for getting servers.

Topologies are associated with their clusters - for example, a ReplicaSet topology contains the replica set name. A topology object therefore cannot be used with multiple cluster objects.

At the same time, topology objects do not know anything about specific servers in a cluster, despite what their constructor may suggest. Which means, in particular, that topology change events require the application to maintain cluster references on its own if it wants to track server changes within a replica set.

@since 2.0.0

Constants

OPTIONS

The various topologies for server selection.

@since 2.0.0

Public Instance Methods

initial(cluster, monitoring, options) click to toggle source

Get the initial cluster topology for the provided options.

@example Get the initial cluster topology.

Topology.initial(topology: :replica_set)

@param [ Cluster ] cluster The cluster. @param [ Monitoring ] monitoring The monitoring. @param [ Hash ] options The cluster options.

@return [ ReplicaSet, Sharded, Single ] The topology.

@since 2.0.0 @api private

# File lib/mongo/cluster/topology.rb, line 69
def initial(cluster, monitoring, options)
  cls = if options.key?(:connect)
    OPTIONS.fetch(options[:connect].to_sym)
  elsif options.key?(:replica_set) || options.key?(:replica_set_name)
    ReplicaSetNoPrimary
  else
    Unknown
  end
  # Options here are client/cluster/server options.
  # In particular the replica set name key is different for
  # topology.
  # If replica_set_name is given (as might be internally by driver),
  # use that key.
  # Otherwise (e.g. options passed down from client),
  # move replica_set to replica_set_name.
  if (cls <= ReplicaSetNoPrimary || cls == Single) && !options[:replica_set_name]
    options = options.dup
    options[:replica_set_name] = options.delete(:replica_set)
  end
  cls.new(options, monitoring, cluster)
end