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author | Konstantin Lazarev <le6oww5k1@gmail.com> | 2016-12-31 23:42:53 +0500 |
---|---|---|
committer | Konstantin Lazarev <le6oww5k1@gmail.com> | 2017-01-03 19:02:38 +0500 |
commit | cdf8a2b49307953fbcd93df9fdec3c23063740b1 (patch) | |
tree | 6f8c50e8bf9e628720b90b6c5cea16f7f5b7531d | |
parent | 33e60514aed85b3076f2636d5f1ccfb513aace1c (diff) | |
download | rails-cdf8a2b49307953fbcd93df9fdec3c23063740b1.tar.gz rails-cdf8a2b49307953fbcd93df9fdec3c23063740b1.tar.bz2 rails-cdf8a2b49307953fbcd93df9fdec3c23063740b1.zip |
Cache results of computing model type
We faced a significant performance decrease when we started using STI
without storing full namespaced class name in type column (because of PostgreSQL
length limit for ENUM types).
We realized that the cause of it is the slow STI model instantiation. Problematic
method appears to be `ActiveRecord::Base.compute_type`, which is used to find
the right class for STI model on every instantiation.
It builds an array of candidate types and then iterates through it calling
`safe_constantize` on every type until it finds appropriate constant. So if
desired type isn't the first element in this array there will be at least one
unsuccessful call to `safe_constantize`, which is very expensive, since it's
defined in terms of `begin; rescue; end`.
This commit is an attempt to speed up `compute_type` method simply by caching
results of previous calls.
```ruby
class MyCompany::MyApp::Business::Accounts::Base < ApplicationRecord
self.table_name = 'accounts'
self.store_full_sti_class = false
end
class MyCompany::MyApp::Business::Accounts::Free < Base
end
class MyCompany::MyApp::Business::Accounts::Standard < Base
# patch .compute_type there
end
puts '======================= .compute_type ======================='
Benchmark.ips do |x|
x.report("original method") do
MyCompany::MyApp::Business::Accounts::Free.send :compute_type, 'Free'
end
x.report("with types cached") do
MyCompany::MyApp::Business::Accounts::Standard.send :compute_type, 'Standard'
end
x.compare!
end
```
```
======================= .compute_type =======================
with types cached: 1529019.4 i/s
original method: 2850.2 i/s - 536.46x slower
```
```ruby
5_000.times do |i|
MyCompany::MyApp::Business::Accounts::Standard.create!(name: "standard_#{i}")
end
5_000.times do |i|
MyCompany::MyApp::Business::Accounts::Free.create!(name: "free_#{i}")
end
puts '====================== .limit(100).to_a ======================='
Benchmark.ips do |x|
x.report("without .compute_type patch") do
MyCompany::MyApp::Business::Accounts::Free.limit(100).to_a
end
x.report("with .compute_type patch") do
MyCompany::MyApp::Business::Accounts::Standard.limit(100).to_a
end
x.compare!
end
```
```
====================== .limit(100).to_a =======================
with .compute_type patch: 360.5 i/s
without .compute_type patch: 24.7 i/s - 14.59x slower
```
-rw-r--r-- | activerecord/CHANGELOG.md | 4 | ||||
-rw-r--r-- | activerecord/lib/active_record/inheritance.rb | 17 | ||||
-rw-r--r-- | activerecord/test/cases/inheritance_test.rb | 14 | ||||
-rw-r--r-- | activerecord/test/cases/reflection_test.rb | 8 |
4 files changed, 33 insertions, 10 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index b59d24f88d..5069c6666f 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,3 +1,7 @@ +* Optimize slow model instantiation when using STI and `store_full_sti_class = false` option. + + *Konstantin Lazarev* + * Add `touch` option to counter cache modifying methods. Works when updating, resetting, incrementing and decrementing counters: diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb index a1d4f47372..fbdaeaae51 100644 --- a/activerecord/lib/active_record/inheritance.rb +++ b/activerecord/lib/active_record/inheritance.rb @@ -130,16 +130,26 @@ module ActiveRecord store_full_sti_class ? name : name.demodulize end + def inherited(subclass) + subclass.instance_variable_set(:@_type_candidates_cache, Concurrent::Map.new) + super + end + protected # Returns the class type of the record using the current module as a prefix. So descendants of # MyApp::Business::Account would appear as MyApp::Business::AccountSubclass. def compute_type(type_name) - if type_name.match(/^::/) + if type_name.start_with?("::".freeze) # If the type is prefixed with a scope operator then we assume that # the type_name is an absolute reference. ActiveSupport::Dependencies.constantize(type_name) else + type_candidate = @_type_candidates_cache[type_name] + if type_candidate && type_constant = ActiveSupport::Dependencies.safe_constantize(type_candidate) + return type_constant + end + # Build a list of candidates to search for candidates = [] name.scan(/::|$/) { candidates.unshift "#{$`}::#{type_name}" } @@ -147,7 +157,10 @@ module ActiveRecord candidates.each do |candidate| constant = ActiveSupport::Dependencies.safe_constantize(candidate) - return constant if candidate == constant.to_s + if candidate == constant.to_s + @_type_candidates_cache[type_name] = candidate + return constant + end end raise NameError.new("uninitialized constant #{candidates.first}", candidates.first) diff --git a/activerecord/test/cases/inheritance_test.rb b/activerecord/test/cases/inheritance_test.rb index 9ad4664567..e570e9ac1d 100644 --- a/activerecord/test/cases/inheritance_test.rb +++ b/activerecord/test/cases/inheritance_test.rb @@ -58,21 +58,21 @@ class InheritanceTest < ActiveRecord::TestCase end def test_compute_type_success - assert_equal Author, ActiveRecord::Base.send(:compute_type, "Author") + assert_equal Author, Company.send(:compute_type, "Author") end def test_compute_type_nonexistent_constant e = assert_raises NameError do - ActiveRecord::Base.send :compute_type, "NonexistentModel" + Company.send :compute_type, "NonexistentModel" end - assert_equal "uninitialized constant ActiveRecord::Base::NonexistentModel", e.message - assert_equal "ActiveRecord::Base::NonexistentModel", e.name + assert_equal "uninitialized constant Company::NonexistentModel", e.message + assert_equal "Company::NonexistentModel", e.name end def test_compute_type_no_method_error ActiveSupport::Dependencies.stub(:safe_constantize, proc { raise NoMethodError }) do assert_raises NoMethodError do - ActiveRecord::Base.send :compute_type, "InvalidModel" + Company.send :compute_type, "InvalidModel" end end end @@ -90,7 +90,7 @@ class InheritanceTest < ActiveRecord::TestCase ActiveSupport::Dependencies.stub(:safe_constantize, proc { raise e }) do exception = assert_raises NameError do - ActiveRecord::Base.send :compute_type, "InvalidModel" + Company.send :compute_type, "InvalidModel" end assert_equal error.message, exception.message end @@ -99,7 +99,7 @@ class InheritanceTest < ActiveRecord::TestCase def test_compute_type_argument_error ActiveSupport::Dependencies.stub(:safe_constantize, proc { raise ArgumentError }) do assert_raises ArgumentError do - ActiveRecord::Base.send :compute_type, "InvalidModel" + Company.send :compute_type, "InvalidModel" end end end diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb index a90058e8bb..0ef51272b9 100644 --- a/activerecord/test/cases/reflection_test.rb +++ b/activerecord/test/cases/reflection_test.rb @@ -100,7 +100,13 @@ class ReflectionTest < ActiveRecord::TestCase end def test_reflection_klass_for_nested_class_name - reflection = ActiveRecord::Reflection.create(:has_many, nil, nil, { class_name: "MyApplication::Business::Company" }, ActiveRecord::Base) + reflection = ActiveRecord::Reflection.create( + :has_many, + nil, + nil, + { class_name: "MyApplication::Business::Company" }, + Customer + ) assert_nothing_raised do assert_equal MyApplication::Business::Company, reflection.klass end |