diff options
7 files changed, 109 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb index c29cf1f9a1..c10765f42d 100644 --- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb +++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb @@ -77,6 +77,11 @@ module ActiveRecord }] end + # Checks whether the columns hash is already cached for a table. + def columns_hash?(table_name) + @columns_hash.key?(table_name) + end + # Clears out internal caches def clear! @columns.clear diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb index fc564d59e2..600825659b 100644 --- a/activerecord/lib/active_record/core.rb +++ b/activerecord/lib/active_record/core.rb @@ -282,6 +282,10 @@ module ActiveRecord TypeCaster::Map.new(self) end + def _internal? # :nodoc: + false + end + private def cached_find_by_statement(key, &block) diff --git a/activerecord/lib/active_record/internal_metadata.rb b/activerecord/lib/active_record/internal_metadata.rb index 3626a13d7c..88b0c828ae 100644 --- a/activerecord/lib/active_record/internal_metadata.rb +++ b/activerecord/lib/active_record/internal_metadata.rb @@ -8,6 +8,10 @@ module ActiveRecord # as which environment migrations were run in. class InternalMetadata < ActiveRecord::Base # :nodoc: class << self + def _internal? + true + end + def primary_key "key" end diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb index 538659d6bd..2ee6119158 100644 --- a/activerecord/lib/active_record/railtie.rb +++ b/activerecord/lib/active_record/railtie.rb @@ -140,7 +140,19 @@ end_error initializer "active_record.define_attribute_methods" do |app| config.after_initialize do ActiveSupport.on_load(:active_record) do - descendants.each(&:define_attribute_methods) if app.config.eager_load + if app.config.eager_load + descendants.each do |model| + # SchemaMigration and InternalMetadata both override `table_exists?` + # to bypass the schema cache, so skip them to avoid the extra queries. + next if model._internal? + + # If there's no connection yet, or the schema cache doesn't have the columns + # hash for the model cached, `define_attribute_methods` would trigger a query. + next unless model.connected? && model.connection.schema_cache.columns_hash?(model.table_name) + + model.define_attribute_methods + end + end end end end diff --git a/activerecord/lib/active_record/schema_migration.rb b/activerecord/lib/active_record/schema_migration.rb index f2d8b038fa..1fca1a18f6 100644 --- a/activerecord/lib/active_record/schema_migration.rb +++ b/activerecord/lib/active_record/schema_migration.rb @@ -10,6 +10,10 @@ module ActiveRecord # to be executed the next time. class SchemaMigration < ActiveRecord::Base # :nodoc: class << self + def _internal? + true + end + def primary_key "version" end diff --git a/activerecord/test/cases/connection_adapters/schema_cache_test.rb b/activerecord/test/cases/connection_adapters/schema_cache_test.rb index 67496381d1..727cab77f5 100644 --- a/activerecord/test/cases/connection_adapters/schema_cache_test.rb +++ b/activerecord/test/cases/connection_adapters/schema_cache_test.rb @@ -91,6 +91,22 @@ module ActiveRecord @cache.clear_data_source_cache!("posts") end + test "#columns_hash? is populated by #columns_hash" do + assert_not @cache.columns_hash?("posts") + + @cache.columns_hash("posts") + + assert @cache.columns_hash?("posts") + end + + test "#columns_hash? is not populated by #data_source_exists?" do + assert_not @cache.columns_hash?("posts") + + @cache.data_source_exists?("posts") + + assert_not @cache.columns_hash?("posts") + end + private def schema_dump_path diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb index 886fb0f843..8eaf07586e 100644 --- a/railties/test/application/configuration_test.rb +++ b/railties/test/application/configuration_test.rb @@ -331,7 +331,7 @@ module ApplicationTests assert_not_includes Post.instance_methods, :title end - test "eager loads attribute methods in production" do + test "does not eager load attribute methods in production when the schema cache is empty" do app_file "app/models/post.rb", <<-RUBY class Post < ActiveRecord::Base end @@ -354,9 +354,71 @@ module ApplicationTests app "production" + assert_not_includes Post.instance_methods, :title + end + + test "eager loads attribute methods in production when the schema cache is populated" do + app_file "app/models/post.rb", <<-RUBY + class Post < ActiveRecord::Base + end + RUBY + + app_file "config/initializers/active_record.rb", <<-RUBY + ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:") + ActiveRecord::Migration.verbose = false + ActiveRecord::Schema.define(version: 1) do + create_table :posts do |t| + t.string :title + end + end + RUBY + + add_to_config <<-RUBY + config.eager_load = true + config.cache_classes = true + RUBY + + app_file "config/initializers/schema_cache.rb", <<-RUBY + ActiveRecord::Base.connection.schema_cache.add("posts") + RUBY + + app "production" + assert_includes Post.instance_methods, :title end + test "does not attempt to eager load attribute methods for models that aren't connected" do + app_file "app/models/post.rb", <<-RUBY + class Post < ActiveRecord::Base + end + RUBY + + app_file "config/initializers/active_record.rb", <<-RUBY + ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:") + ActiveRecord::Migration.verbose = false + ActiveRecord::Schema.define(version: 1) do + create_table :posts do |t| + t.string :title + end + end + RUBY + + add_to_config <<-RUBY + config.eager_load = true + config.cache_classes = true + RUBY + + app_file "app/models/comment.rb", <<-RUBY + class Comment < ActiveRecord::Base + establish_connection(adapter: "mysql2", database: "does_not_exist") + end + RUBY + + assert_nothing_raised do + app "production" + end + end + test "initialize an eager loaded, cache classes app" do add_to_config <<-RUBY config.eager_load = true |