remove the HABTM preloader

2 files changed, 0 insertions, 74 deletions

diff --git a/activerecord/lib/active_record/associations/preloader.rb b/activerecord/lib/active_record/associations/preloader.rb
index 127d0e2642..713ff80d47 100644
--- a/activerecord/lib/active_record/associations/preloader.rb
+++ b/activerecord/lib/active_record/associations/preloader.rb
@@ -42,7 +42,6 @@ module ActiveRecord
         autoload :HasManyThrough,      'active_record/associations/preloader/has_many_through'
         autoload :HasOne,              'active_record/associations/preloader/has_one'
         autoload :HasOneThrough,       'active_record/associations/preloader/has_one_through'
-        autoload :HasAndBelongsToMany, 'active_record/associations/preloader/has_and_belongs_to_many'
         autoload :BelongsTo,           'active_record/associations/preloader/belongs_to'
       end
 
@@ -205,8 +204,6 @@ module ActiveRecord
           reflection.options[:through] ? HasManyThrough : HasMany
         when :has_one
           reflection.options[:through] ? HasOneThrough : HasOne
-        when :has_and_belongs_to_many
-          HasAndBelongsToMany
         when :belongs_to
           BelongsTo
         end
diff --git a/activerecord/lib/active_record/associations/preloader/has_and_belongs_to_many.rb b/activerecord/lib/active_record/associations/preloader/has_and_belongs_to_many.rb
deleted file mode 100644
index b62ca6f681..0000000000
--- a/activerecord/lib/active_record/associations/preloader/has_and_belongs_to_many.rb
+++ /dev/null
@@ -1,71 +0,0 @@
-module ActiveRecord
-  module Associations
-    class Preloader
-      class HasAndBelongsToMany < CollectionAssociation #:nodoc:
-        attr_reader :join_table
-
-        def initialize(klass, records, reflection, preload_options)
-          super
-          @join_table = Arel::Table.new(reflection.join_table).alias('t0')
-        end
-
-        # Unlike the other associations, we want to get a raw array of rows so that we can
-        # access the aliased column on the join table
-        def records_for(ids)
-          scope = query_scope ids
-          klass.connection.select_all(scope.arel, 'SQL', scope.bind_values)
-        end
-
-        def owner_key_name
-          reflection.active_record_primary_key
-        end
-
-        def association_key_name
-          'ar_association_key_name'
-        end
-
-        def association_key
-          join_table[reflection.foreign_key]
-        end
-
-        private
-
-        # Once we have used the join table column (in super), we manually instantiate the
-        # actual records, ensuring that we don't create more than one instances of the same
-        # record
-        def load_slices(slices)
-          identity_map = {}
-          caster = nil
-          name = association_key_name
-
-          records_to_keys = slices.flat_map { |slice|
-            records = records_for(slice)
-            caster ||= records.column_types.fetch(name, records.identity_type)
-            records.map! { |row|
-              record = identity_map[row[klass.primary_key]] ||= klass.instantiate(row)
-              [record, caster.type_cast(row[name])]
-            }
-          }
-          @preloaded_records = records_to_keys.map(&:first)
-
-          records_to_keys
-        end
-
-        def build_scope
-          super.joins(join).select(join_select)
-        end
-
-        def join_select
-          association_key.as(Arel.sql(association_key_name))
-        end
-
-        def join
-          condition = table[reflection.association_primary_key].eq(
-            join_table[reflection.association_foreign_key])
-
-          table.create_join(join_table, table.create_on(condition))
-        end
-      end
-    end
-  end
-end