Lazily-evaluated relationships #29
Description
I'm performance tuning some of my endpoints and I've noticed that JSONAPI::Serializers is triggering database calls on relationships even when those relationships are not given in the included option (i.e. included is nil). The results of these database calls are not being included in the output. Is this intentional, and if so, is there a way to tell JSONAPI::Serializers to lazily-evaluate relationships? If not intentional, is it possible there is some some class instantiation logic that is inspecting or otherwise poking the relationships that is causing the upstream Sequel::Model to fire off queries?
require 'sequel'
require 'jsonapi-serializers'
require 'logger'
require 'pp'
DB = Sequel.sqlite nil,
:loggers => [Logger.new($stdout)]
DB.create_table :foos do
primary_key :id
foreign_key :bar_id, :bars
String :name
end
DB.create_table :bars do
primary_key :id
end
DB.run "INSERT INTO bars (id) VALUES (1)"
DB.run "INSERT INTO foos (id, bar_id, name) VALUES (1, 1, 'myfoo')"
class Foo < Sequel::Model
many_to_one :bar
end
class Bar < Sequel::Model
one_to_many :foos
end
class FooSerializer
include JSONAPI::Serializer
attribute :name
has_one :bar
end
class BarSerializer
include JSONAPI::Serializer
has_many :foos
end
pp JSONAPI::Serializer.serialize(Foo.first, {
:is_collection => false,
:skip_collection_check => true
})And the output:
$ bundle show jsonapi-serializers
/home/mwp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/jsonapi-serializers-0.3.0
$ bundle show sequel
/home/mwp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/sequel-4.25.0
$ ruby --version
ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-linux]
$ ruby main.rb
I, [2015-10-13T15:01:17.021499 #24657] INFO -- : (0.000207s) PRAGMA foreign_keys = 1
I, [2015-10-13T15:01:17.021745 #24657] INFO -- : (0.000031s) PRAGMA case_sensitive_like = 1
I, [2015-10-13T15:01:17.022125 #24657] INFO -- : (0.000270s) CREATE TABLE `foos` (`id` integer NOT NULL PRIMARY KEY AUTOINCREMENT, `bar_id` integer REFERENCES `bars`, `name` varchar(255))
I, [2015-10-13T15:01:17.022445 #24657] INFO -- : (0.000118s) CREATE TABLE `bars` (`id` integer NOT NULL PRIMARY KEY AUTOINCREMENT)
I, [2015-10-13T15:01:17.022600 #24657] INFO -- : (0.000053s) INSERT INTO bars (id) VALUES (1)
I, [2015-10-13T15:01:17.022759 #24657] INFO -- : (0.000053s) INSERT INTO foos (id, bar_id, name) VALUES (1, 1, 'myfoo')
I, [2015-10-13T15:01:17.023645 #24657] INFO -- : (0.000307s) PRAGMA table_info('foos')
I, [2015-10-13T15:01:17.024828 #24657] INFO -- : (0.000089s) PRAGMA table_info('bars')
I, [2015-10-13T15:01:17.025724 #24657] INFO -- : (0.000076s) SELECT sqlite_version()
I, [2015-10-13T15:01:17.026072 #24657] INFO -- : (0.000168s) SELECT * FROM `foos` LIMIT 1
I, [2015-10-13T15:01:17.026730 #24657] INFO -- : (0.000078s) SELECT * FROM `bars` WHERE `id` = 1
{"data"=>
{"id"=>"1",
"type"=>"foos",
"attributes"=>{"name"=>"myfoo"},
"links"=>{"self"=>"/foos/1"},
"relationships"=>
{"bar"=>
{"links"=>
{"self"=>"/foos/1/relationships/bar", "related"=>"/foos/1/bar"}}}}}
The last INFO line (SELECT * FROM barsWHEREid = 1) is what I'm trying to eliminate.