Passing klass to StatementCache.new

Actually `StatementCache#execute` is always passed the same klass that
the owner klass of the connection when the statement cache is created.
So passing `klass` to `StatementCache.new` will make more DRY.

activerecord/lib/active_record/associations/collection_association.rb

@@ -304,15 +304,13 @@ module ActiveRecord
           return scope.to_a if skip_statement_cache?(scope)
 
           conn = klass.connection
-          sc = reflection.association_scope_cache(conn, owner) do
-            StatementCache.create(conn) { |params|
-              as = AssociationScope.create { params.bind }
-              target_scope.merge!(as.scope(self))
-            }
+          sc = reflection.association_scope_cache(conn, owner) do |params|
+            as = AssociationScope.create { params.bind }
+            target_scope.merge!(as.scope(self))
           end
 
           binds = AssociationScope.get_bind_values(owner, reflection.chain)
-          sc.execute(binds, klass, conn) do |record|
+          sc.execute(binds, conn) do |record|
             set_inverse_instance(record)
           end
         end

activerecord/lib/active_record/associations/singular_association.rb

@@ -41,15 +41,13 @@ module ActiveRecord
           return scope.take if skip_statement_cache?(scope)
 
           conn = klass.connection
-          sc = reflection.association_scope_cache(conn, owner) do
-            StatementCache.create(conn) { |params|
-              as = AssociationScope.create { params.bind }
-              target_scope.merge!(as.scope(self)).limit(1)
-            }
+          sc = reflection.association_scope_cache(conn, owner) do |params|
+            as = AssociationScope.create { params.bind }
+            target_scope.merge!(as.scope(self)).limit(1)
           end
 
           binds = AssociationScope.get_bind_values(owner, reflection.chain)
-          sc.execute(binds, klass, conn) do |record|
+          sc.execute(binds, conn) do |record|
             set_inverse_instance record
           end.first
         rescue ::RangeError

activerecord/lib/active_record/core.rb

@@ -176,7 +176,7 @@ module ActiveRecord
           where(key => params.bind).limit(1)
         }
 
-        record = statement.execute([id], self, connection).first
+        record = statement.execute([id], connection).first
         unless record
           raise RecordNotFound.new("Couldn't find #{name} with '#{primary_key}'=#{id}",
                                    name, primary_key, id)
@@ -208,7 +208,7 @@ module ActiveRecord
           where(wheres).limit(1)
         }
         begin
-          statement.execute(hash.values, self, connection).first
+          statement.execute(hash.values, connection).first
         rescue TypeError
           raise ActiveRecord::StatementInvalid
         rescue ::RangeError

activerecord/lib/active_record/reflection.rb

@@ -458,13 +458,13 @@ module ActiveRecord
         end
       end
 
-      def association_scope_cache(conn, owner)
+      def association_scope_cache(conn, owner, &block)
         key = conn.prepared_statements
         if polymorphic?
           key = [key, owner._read_attribute(@foreign_type)]
         end
         @association_scope_cache[key] ||= @scope_lock.synchronize {
-          @association_scope_cache[key] ||= yield
+          @association_scope_cache[key] ||= StatementCache.create(conn, &block)
         }
       end
 

activerecord/lib/active_record/statement_cache.rb

@@ -11,7 +11,7 @@ module ActiveRecord
   # The cached statement is executed by using the
   # {connection.execute}[rdoc-ref:ConnectionAdapters::DatabaseStatements#execute] method:
   #
-  #   cache.execute([], Book, Book.connection)
+  #   cache.execute([], Book.connection)
   #
   # The relation returned by the block is cached, and for each
   # {execute}[rdoc-ref:ConnectionAdapters::DatabaseStatements#execute]
@@ -26,7 +26,7 @@ module ActiveRecord
   #
   # And pass the bind values as the first argument of +execute+ call.
   #
-  #   cache.execute(["my book"], Book, Book.connection)
+  #   cache.execute(["my book"], Book.connection)
   class StatementCache # :nodoc:
     class Substitute; end # :nodoc:
 
@@ -87,21 +87,20 @@ module ActiveRecord
       end
     end
 
-    attr_reader :bind_map, :query_builder
-
     def self.create(connection, block = Proc.new)
       relation = block.call Params.new
       query_builder, binds = connection.cacheable_query(self, relation.arel)
       bind_map = BindMap.new(binds)
-      new query_builder, bind_map
+      new(query_builder, bind_map, relation.klass)
     end
 
-    def initialize(query_builder, bind_map)
+    def initialize(query_builder, bind_map, klass)
       @query_builder = query_builder
-      @bind_map      = bind_map
+      @bind_map = bind_map
+      @klass = klass
     end
 
-    def execute(params, klass, connection, &block)
+    def execute(params, connection, &block)
       bind_values = bind_map.bind params
 
       sql = query_builder.sql_for bind_values, connection
@@ -114,5 +113,9 @@ module ActiveRecord
       when NilClass, Array, Range, Hash, Relation, Base then true
       end
     end
+
+    protected
+
+      attr_reader :query_builder, :bind_map, :klass
   end
 end

activerecord/test/cases/statement_cache_test.rb

@@ -21,9 +21,9 @@ module ActiveRecord
         Book.where(name: params.bind)
       end
 
-      b = cache.execute([ "my book" ], Book, Book.connection)
+      b = cache.execute([ "my book" ], Book.connection)
       assert_equal "my book", b[0].name
-      b = cache.execute([ "my other book" ], Book, Book.connection)
+      b = cache.execute([ "my other book" ], Book.connection)
       assert_equal "my other book", b[0].name
     end
 
@@ -35,9 +35,9 @@ module ActiveRecord
         Book.where(id: params.bind)
       end
 
-      b = cache.execute([ b1.id ], Book, Book.connection)
+      b = cache.execute([ b1.id ], Book.connection)
       assert_equal b1.name, b[0].name
-      b = cache.execute([ b2.id ], Book, Book.connection)
+      b = cache.execute([ b2.id ], Book.connection)
       assert_equal b2.name, b[0].name
     end
 
@@ -60,7 +60,7 @@ module ActiveRecord
 
       Book.create(name: "my book", author_id: 4)
 
-      books = cache.execute([], Book, Book.connection)
+      books = cache.execute([], Book.connection)
       assert_equal "my book", books[0].name
     end
 
@@ -73,7 +73,7 @@ module ActiveRecord
       molecule = salty.molecules.create(name: "dioxane")
       molecule.electrons.create(name: "lepton")
 
-      liquids = cache.execute([], Book, Book.connection)
+      liquids = cache.execute([], Book.connection)
       assert_equal "salty", liquids[0].name
     end
 
@@ -86,13 +86,13 @@ module ActiveRecord
         Book.create(name: "my book")
       end
 
-      first_books = cache.execute([], Book, Book.connection)
+      first_books = cache.execute([], Book.connection)
 
       3.times do
         Book.create(name: "my book")
       end
 
-      additional_books = cache.execute([], Book, Book.connection)
+      additional_books = cache.execute([], Book.connection)
       assert first_books != additional_books
     end