diff options
| -rw-r--r-- | activerecord/lib/active_record/integration.rb | 52 | ||||
| -rw-r--r-- | activerecord/test/cases/cache_key_test.rb | 82 |
2 files changed, 130 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/integration.rb b/activerecord/lib/active_record/integration.rb index 33c4066b89..ec39ece87f 100644 --- a/activerecord/lib/active_record/integration.rb +++ b/activerecord/lib/active_record/integration.rb @@ -96,8 +96,19 @@ module ActiveRecord # Note, this method will return nil if ActiveRecord::Base.cache_versioning is set to # +false+ (which it is by default until Rails 6.0). def cache_version - if cache_versioning && timestamp = try(:updated_at) - timestamp.utc.to_s(:usec) + return unless cache_versioning + + if has_attribute?("updated_at") + timestamp = updated_at_before_type_cast + if can_use_fast_cache_version?(timestamp) + raw_timestamp_to_cache_version(timestamp) + elsif timestamp = updated_at + timestamp.utc.to_s(cache_timestamp_format) + end + else + if self.class.has_attribute?("updated_at") + raise ActiveModel::MissingAttributeError, "missing attribute: updated_at" + end end end @@ -151,5 +162,42 @@ module ActiveRecord end end end + + private + # Detects if the value before type cast + # can be used to generate a cache_version. + # + # The fast cache version only works with a + # string value directly from the database. + # + # We also must check if the timestamp format has been changed + # or if the timezone is not set to UTC then + # we cannot apply our transformations correctly. + def can_use_fast_cache_version?(timestamp) + timestamp.is_a?(String) && + cache_timestamp_format == :usec && + default_timezone == :utc && + !updated_at_came_from_user? + end + + # Converts a raw database string to `:usec` + # format. + # + # Example: + # + # timestamp = "2018-10-15 20:02:15.266505" + # raw_timestamp_to_cache_version(timestamp) + # # => "20181015200215266505" + # + # Postgres truncates trailing zeros, https://bit.ly/2QUlXiZ + # to account for this we pad the output with zeros + def raw_timestamp_to_cache_version(timestamp) + key = timestamp.delete("- :.") + if key.length < 20 + key.ljust(20, "0") + else + key + end + end end end diff --git a/activerecord/test/cases/cache_key_test.rb b/activerecord/test/cases/cache_key_test.rb index 3a569f226e..3a06b1c795 100644 --- a/activerecord/test/cases/cache_key_test.rb +++ b/activerecord/test/cases/cache_key_test.rb @@ -44,10 +44,88 @@ module ActiveRecord test "cache_key_with_version always has both key and version" do r1 = CacheMeWithVersion.create - assert_equal "active_record/cache_key_test/cache_me_with_versions/#{r1.id}-#{r1.updated_at.to_s(:usec)}", r1.cache_key_with_version + assert_equal "active_record/cache_key_test/cache_me_with_versions/#{r1.id}-#{r1.updated_at.utc.to_s(:usec)}", r1.cache_key_with_version r2 = CacheMe.create - assert_equal "active_record/cache_key_test/cache_mes/#{r2.id}-#{r2.updated_at.to_s(:usec)}", r2.cache_key_with_version + assert_equal "active_record/cache_key_test/cache_mes/#{r2.id}-#{r2.updated_at.utc.to_s(:usec)}", r2.cache_key_with_version + end + + test "cache_version is the same when it comes from the DB or from the user" do + skip("Mysql2 does not return a string value for updated_at") if current_adapter?(:Mysql2Adapter) + + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.find(record.id) + assert_not_called(record_from_db, :updated_at) do + record_from_db.cache_version + end + + assert_equal record.cache_version, record_from_db.cache_version + end + + test "cache_version does not truncate zeros when timestamp ends in zeros" do + skip("Mysql2 does not return a string value for updated_at") if current_adapter?(:Mysql2Adapter) + + travel_to Time.now.beginning_of_day do + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.find(record.id) + assert_not_called(record_from_db, :updated_at) do + record_from_db.cache_version + end + + assert_equal record.cache_version, record_from_db.cache_version + end + end + + test "cache_version calls updated_at when the value is generated at create time" do + record = CacheMeWithVersion.create + assert_called(record, :updated_at) do + record.cache_version + end + end + + test "cache_version does NOT call updated_at when value is from the database" do + skip("Mysql2 does not return a string value for updated_at") if current_adapter?(:Mysql2Adapter) + + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.find(record.id) + assert_not_called(record_from_db, :updated_at) do + record_from_db.cache_version + end + end + + test "cache_version does call updated_at when it is assigned via a Time object" do + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.find(record.id) + assert_called(record_from_db, :updated_at) do + record_from_db.updated_at = Time.now + record_from_db.cache_version + end + end + + test "cache_version does call updated_at when it is assigned via a string" do + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.find(record.id) + assert_called(record_from_db, :updated_at) do + record_from_db.updated_at = Time.now.to_s + record_from_db.cache_version + end + end + + test "cache_version does call updated_at when it is assigned via a hash" do + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.find(record.id) + assert_called(record_from_db, :updated_at) do + record_from_db.updated_at = { 1 => 2016, 2 => 11, 3 => 12, 4 => 1, 5 => 2, 6 => 3, 7 => 22 } + record_from_db.cache_version + end + end + + test "updated_at on class but not on instance raises an error" do + record = CacheMeWithVersion.create + record_from_db = CacheMeWithVersion.where(id: record.id).select(:id).first + assert_raises(ActiveModel::MissingAttributeError) do + record_from_db.cache_version + end end end end |