Merge pull request #597 from estolfo/RUBY-891-standalone

RUBY-891 Single topology type servers and slaveOk bit

Author: estolfo

lib/mongo/cluster.rb

@@ -69,7 +69,8 @@ def add(host)
       unless addresses.include?(address)
         log_debug([ "Adding #{address.to_s} to the cluster." ])
         addresses.push(address)
-        server = Server.new(address, event_listeners, options)
+        server = Server.new(address, event_listeners,
+                            options.merge(slave_ok: @slave_ok))
         @servers.push(server)
         server
       end
@@ -90,6 +91,7 @@ def initialize(seeds, options = {})
       @event_listeners = Event::Listeners.new
       @options = options.freeze
       @topology = Topology.initial(seeds, options)
+      @slave_ok = @topology.single? unless options[:read]
 
       subscribe_to(Event::SERVER_ADDED, Event::ServerAdded.new(self))
       subscribe_to(Event::SERVER_REMOVED, Event::ServerRemoved.new(self))

lib/mongo/cluster/topology/single.rb

@@ -94,9 +94,7 @@ def replica_set_name; nil; end
         #
         # @since 2.0.0
         def servers(servers, name = nil)
-          [ servers.detect do |server|
-              !server.unknown? && !server.arbiter? && !server.ghost?
-            end ]
+          [ servers.detect { |server| !server.unknown? } ]
         end
 
         # A single topology is not sharded.

lib/mongo/operation/read_preferrable.rb

@@ -22,11 +22,27 @@ module ReadPreferrable
 
       private
 
+      def update_selector(context)
+        if context.mongos? && read_pref = read.to_mongos
+          selector.merge(:$readPreference => read_pref)
+        else
+          selector
+        end
+      end
+
+      def update_options(context)
+        if context.slave_ok?
+          options.merge(flags: [:slave_ok])
+        elsif !context.mongos? && read.slave_ok?
+          options.merge(flags: [:slave_ok])
+        else
+          options
+        end
+      end
+
       def message(context)
-        sel = (context.mongos? && read_pref = read.to_mongos) ?
-                selector.merge(:$readPreference => read_pref) : selector
-        opts = context.standalone? || read.slave_ok? ?
-                 options.merge(flags: [:slave_ok]) : options
+        sel = update_selector(context)
+        opts = update_options(context)
         Protocol::Query.new(db_name, query_coll, sel, opts)
       end
     end

lib/mongo/server.rb

@@ -159,5 +159,17 @@ def matches_tag_set?(tag_set)
         tags[k] && tags[k] == tag_set[k]
       end
     end
+
+    # Whether the slaveOk bit must be set for all queries sent to the server.
+    #
+    # @example Does the slaveOk bit need to be set for all queries sent to the server.
+    #   server.slave_ok?
+    #
+    # @return [ true, false ] If the slaveOk bit needs to be set for all queries.
+    #
+    # @since 2.0.0
+    def slave_ok?
+      options[:slave_ok]
+    end
   end
 end

lib/mongo/server/context.rb

@@ -33,7 +33,8 @@ class Context
                      :mongos?,
                      :primary?,
                      :secondary?,
-                     :standalone?
+                     :standalone?,
+                     :slave_ok?
 
       # Instantiate a server context.
       #

spec/support/shared/operation.rb

@@ -43,6 +43,7 @@
       allow(cxt).to receive(:primary?) { true }
       allow(cxt).to receive(:secondary?) { false }
       allow(cxt).to receive(:standalone?) { false }
+      allow(cxt).to receive(:slave_ok?) { false }
     end
   end
   let(:secondary_context) do
@@ -54,6 +55,7 @@
       allow(cxt).to receive(:secondary?) { true }
       allow(cxt).to receive(:primary?) { false }
       allow(cxt).to receive(:standalone?) { false }
+      allow(cxt).to receive(:slave_ok?) { false }
     end
   end
   let(:primary_context_2_4_version) do
@@ -64,6 +66,7 @@
       allow(cxt).to receive(:primary?) { true }
       allow(cxt).to receive(:secondary?) { false }
       allow(cxt).to receive(:standalone?) { false }
+      allow(cxt).to receive(:slave_ok?) { false }
       allow(cxt).to receive(:features) { features_2_4 }
     end
   end