Moved hint call from Cursor into Collection#find options and Query#initialize

parameter.

lib/mongo/collection.rb

@@ -23,27 +23,18 @@ module XGen
       # A named collection of records in a database.
       class Collection
 
-        attr_reader :db, :name, :hint_fields
+        attr_reader :db, :name, :hint
 
         def initialize(db, name)
           @db = db
           @name = name
         end
 
-        # Set hint fields to use and return +self+. hint_fields may be a
+        # Set hint fields to use and return +self+. hint may be a
         # single field name, array of field names, or a hash whose keys will
         # become the hint field names. May be +nil+.
-        def hint(hint_fields)
+        def hint=(hint)
-          @hint_fields = case hint_fields
+          @hint = normalize_hint_fields(hint)
-                         when String
-                           [hint_fields]
-                         when Hash
-                           hint_fields.keys
-                         when nil
-                           nil
-                         else
-                           hint_fields.to_a
-                         end
           self
         end
 
@@ -57,14 +48,21 @@ module XGen
         # :sort :: Either hash of field names as keys and 1/-1 as values; 1 ==
         #          ascending, -1 == descending, or array of field names (all
         #          assumed to be sorted in ascending order).
+        # :hint :: See #hint. This option overrides the collection-wide value.
         def find(selector={}, options={})
           fields = options.delete(:fields)
           fields = nil if fields && fields.empty?
           offset = options.delete(:offset) || 0
           limit = options.delete(:limit) || 0
           sort = options.delete(:sort)
+          hint = options.delete(:hint)
+          if hint
+            hint = normalize_hint_fields(hint)
+          else
+            hint = @hint
+          end
           raise RuntimeError, "Unknown options [#{options.inspect}]" unless options.empty?
-          @db.query(self, Query.new(selector, fields, offset, limit, sort))
+          @db.query(self, Query.new(selector, fields, offset, limit, sort, hint))
         end
 
         # Insert +objects+, which are hashes. "<<" is aliased to this method.
@@ -154,6 +152,20 @@ module XGen
           @db.count(@name, selector || {})
         end
 
+        protected
+
+        def normalize_hint_fields(hint)
+          case hint
+          when String
+            [hint]
+          when Hash
+            hint.keys
+          when nil
+            nil
+          else
+            hint.to_a
+          end
+        end
       end
     end
   end

lib/mongo/cursor.rb

@@ -42,24 +42,6 @@ module XGen
 
         def closed?; @closed; end
 
-        # Set hint fields to use and return +self+. hint_fields may be a
-        # single field name, array of field names, or a hash whose keys will
-        # become the hint field names. May be +nil+. If no hint fields are
-        # specified, the ones in the collection are used if they exist.
-        def hint(hint_fields)
-          @hint_fields = case hint_fields
-                         when String
-                           [hint_fields]
-                         when Hash
-                           hint_fields.keys
-                         when nil
-                           nil
-                         else
-                           hint_fields.to_a
-                         end
-          self
-        end
-
         # Return +true+ if there are more records to retrieve. We do not check
         # @num_to_return; #each is responsible for doing that.
         def more?
@@ -223,12 +205,8 @@ module XGen
         def send_query_if_needed
           # Run query first time we request an object from the wire
           unless @query_run
-            hints = @hint_fields || @collection.hint_fields
-            old_hints = @query.hint_fields
-            @query.hint_fields = hints
             @db.send_query_message(QueryMessage.new(@db.name, @collection.name, @query))
             @query_run = true
-            @query.hint_fields = old_hints
             read_all
           end
         end

lib/mongo/message/query_message.rb

@@ -44,9 +44,9 @@ module XGen
                                  raise "illegal order_by: is a #{query.order_by.class.name}, must be String, Array, Hash, or OrderedHash"
                                end
             end
-            if query.hint_fields && query.hint_fields.length > 0
+            if query.hint && query.hint.length > 0
               hints = OrderedHash.new
-              query.hint_fields.each { |hf| hints[hf] = 1 }
+              query.hint.each { |hf| hints[hf] = 1 }
               sel['$hint'] = hints
             end
             if query.explain

lib/mongo/query.rb

@@ -29,7 +29,7 @@ module XGen
         # If true, $explain will be set in QueryMessage that uses this query.
         attr_accessor :explain
         # Either +nil+ or an array of hint field names.
-        attr_accessor :hint_fields
+        attr_accessor :hint
         attr_reader :selector   # writer defined below
 
         # sel :: A hash describing the query. See the Mongo docs for details.
@@ -58,8 +58,12 @@ module XGen
         #             probably will not be what you intend because key order
         #             is not preserved. (order_by is called :sort in calls to
         #             Collection#find.)
-        def initialize(sel={}, return_fields=nil, number_to_skip=0, number_to_return=0, order_by=nil)
+        #
-          @number_to_skip, @number_to_return, @order_by = number_to_skip, number_to_return, order_by
+        # hint :: If not +nil+, specifies query hint fields. See
+        #                Collection#hint.
+        def initialize(sel={}, return_fields=nil, number_to_skip=0, number_to_return=0, order_by=nil, hint=nil)
+          @number_to_skip, @number_to_return, @order_by, @hint =
+            number_to_skip, number_to_return, order_by, hint
           self.selector = sel
           self.fields = return_fields
         end
@@ -102,7 +106,7 @@ module XGen
         end
 
         def contains_special_fields
-          (@order_by != nil && @order_by.length > 0) || @explain || @hint_fields
+          (@order_by != nil && @order_by.length > 0) || @explain || @hint
         end
       end
     end

tests/test_cursor.rb

@@ -54,13 +54,4 @@ class CursorTest < Test::Unit::TestCase
     end
   end
 
-  def test_hint
-    begin
-      cursor = @coll.find('a' => 1).hint('a')
-      assert_equal 1, cursor.to_a.size
-    rescue => ex
-      fail ex.to_s
-    end
-  end
-
 end

tests/test_db_api.rb

@@ -372,4 +372,31 @@ class DBAPITest < Test::Unit::TestCase
     assert_equal "#{@db.host}:#{@db.port}", @db.master
   end
 
+  def test_hint
+    begin
+      assert_nil @coll.hint
+      assert_equal 1, @coll.find({'a' => 1}, :hint => 'a').to_a.size
+      assert_equal 1, @coll.find({'a' => 1}, :hint => ['a']).to_a.size
+      assert_equal 1, @coll.find({'a' => 1}, :hint => {'a' => 1}).to_a.size
+
+      @coll.hint = 'a'
+      assert_equal ['a'], @coll.hint
+      assert_equal 1, @coll.find('a' => 1).to_a.size
+
+      @coll.hint = ['a']
+      assert_equal ['a'], @coll.hint
+      assert_equal 1, @coll.find('a' => 1).to_a.size
+
+      @coll.hint = {'a' => 1}
+      assert_equal ['a'], @coll.hint
+      assert_equal 1, @coll.find('a' => 1).to_a.size
+
+      @coll.hint = nil
+      assert_nil @coll.hint
+      assert_equal 1, @coll.find('a' => 1).to_a.size
+    rescue => ex
+      fail ex.to_s
+    end
+  end
+
 end