Revert "Remove Marshal support from SchemaCache"

This reverts commit 65f2eeaaf5774f0891fff700f4defb0b90a05789.

2 files changed, 29 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
index 5b598620d3..07453b4403 100644
--- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -114,6 +114,17 @@ module ActiveRecord
         @indexes.delete name
       end
 
+      def marshal_dump
+        # if we get current version during initialization, it happens stack over flow.
+        @version = connection.migration_context.current_version
+        [@version, @columns, @columns_hash, @primary_keys, @data_sources, @indexes]
+      end
+
+      def marshal_load(array)
+        @version, @columns, @columns_hash, @primary_keys, @data_sources, @indexes = array
+        @indexes = @indexes || {}
+      end
+
       private
         def prepare_data_sources
           connection.data_sources.each { |source| @data_sources[source] = true }
diff --git a/activerecord/test/cases/connection_adapters/schema_cache_test.rb b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
index 722db1f69f..5113548091 100644
--- a/activerecord/test/cases/connection_adapters/schema_cache_test.rb
+++ b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
@@ -86,6 +86,24 @@ module ActiveRecord
         assert_equal 0, @cache.size
       end
 
+      def test_dump_and_load
+        @cache.columns("posts")
+        @cache.columns_hash("posts")
+        @cache.data_sources("posts")
+        @cache.primary_keys("posts")
+        @cache.indexes("posts")
+
+        @cache = Marshal.load(Marshal.dump(@cache))
+
+        assert_no_queries do
+          assert_equal 12, @cache.columns("posts").size
+          assert_equal 12, @cache.columns_hash("posts").size
+          assert @cache.data_sources("posts")
+          assert_equal "id", @cache.primary_keys("posts")
+          assert_equal 1, @cache.indexes("posts").size
+        end
+      end
+
       def test_data_source_exist
         assert @cache.data_source_exists?("posts")
         assert_not @cache.data_source_exists?("foo")