Pass Collection object, not name, to query so that we can access its hint fields at query time.

lib/mongo/admin.rb

@@ -66,7 +66,7 @@ module XGen
         # Return an array contining current profiling information from the
         # database.
         def profiling_info
-          @db.query(DB::SYSTEM_PROFILE_COLLECTION, Query.new({})).to_a
+          @db.query(Collection.new(@db, DB::SYSTEM_PROFILE_COLLECTION), Query.new({})).to_a
         end
 
         # Validate a named collection by raising an exception if there is a

lib/mongo/collection.rb

@@ -25,6 +25,9 @@ module XGen
 
         attr_reader :db, :name
 
+        # A single field name or array of field names. May be +nil+.
+        attr_accessor :hint_fields
+
         def initialize(db, name)
           @db = db
           @name = name
@@ -47,7 +50,7 @@ module XGen
           limit = options.delete(:limit) || 0
           sort = options.delete(:sort)
           raise RuntimeError, "Unknown options [#{options.inspect}]" unless options.empty?
-          @db.query(@name, Query.new(selector, fields, offset, limit, sort))
+          @db.query(self, Query.new(selector, fields, offset, limit, sort))
         end
 
         # Insert +objects+, which are hashes. "<<" is aliased to this method.

lib/mongo/cursor.rb

@@ -31,6 +31,9 @@ module XGen
 
         attr_reader :db, :collection, :query_message
 
+        # A single field name or array of field names. May be +nil+.
+        attr_accessor :hint_fields
+
         def initialize(db, collection, query_message)
           @db, @collection, @query_message = db, collection, query_message
           @num_to_return = query_message.query.number_to_return || 0
@@ -110,7 +113,7 @@ module XGen
           sel = OrderedHash.new
           sel['query'] = @query_message.query.selector
           sel['$explain'] = true
-          c = Cursor.new(@db, @collection, QueryMessage.new(@db.name, @collection, Query.new(sel)))
+          c = Cursor.new(@db, @collection, QueryMessage.new(@db.name, @collection.name, Query.new(sel)))
           e = c.next_object
           c.close
           e
@@ -173,7 +176,7 @@ module XGen
         def refill_via_get_more
           send_query_if_needed
           return if @cursor_id == 0
-          @db.send_to_db(GetMoreMessage.new(@db.name, @collection, @cursor_id))
+          @db.send_to_db(GetMoreMessage.new(@db.name, @collection.name, @cursor_id))
           read_all
         end
 

lib/mongo/db.rb

@@ -84,7 +84,7 @@ module XGen
         def collections_info(coll_name=nil)
           selector = {}
           selector[:name] = full_coll_name(coll_name) if coll_name
-          query(SYSTEM_NAMESPACE_COLLECTION, Query.new(selector))
+          query(Collection.new(self, SYSTEM_NAMESPACE_COLLECTION), Query.new(selector))
         end
 
         # Create a collection. If +strict+ is false, will return existing or
@@ -182,8 +182,8 @@ module XGen
         # Note that the query gets sent lazily; the cursor calls
         # #send_query_message when needed. If the caller never requests an
         # object from the cursor, the query never gets sent.
-        def query(collection_name, query)
+        def query(collection, query)
-          Cursor.new(self, collection_name, QueryMessage.new(@name, collection_name, query))
+          Cursor.new(self, collection, QueryMessage.new(@name, collection.name, query))
         end
 
         # Used by a Cursor to lazily send the query to the database.
@@ -256,7 +256,7 @@ module XGen
         # :ns :: Namespace; same as +collection_name+.
         def index_information(collection_name)
           sel = {:ns => full_coll_name(collection_name)}
-          query(SYSTEM_INDEX_COLLECTION, Query.new(sel)).collect { |row|
+          query(Collection.new(self, SYSTEM_INDEX_COLLECTION), Query.new(sel)).collect { |row|
             h = {:name => row['name']}
             raise "Name of index on return from db was nil. Coll = #{full_coll_name(collection_name)}" unless h[:name]
 
@@ -321,7 +321,7 @@ module XGen
 
           q = Query.new(selector)
           q.number_to_return = 1
-          query(SYSTEM_COMMAND_COLLECTION, q).next_object
+          query(Collection.new(self, SYSTEM_COMMAND_COLLECTION), q).next_object
         end
 
       end