This add support for sending an explicit opt-out of the "Russian-doll"
cache digest feature on a case-by-case basis. This is useful when cache-
expiration needs to be performed manually and it would be otherwise
difficult to know the exact name of a digested cache key.
More information: https://github.com/rails/cache_digests/pull/16
This yields a small bit of performance improvement when building the
defaults from constraints, specially considering that it's rather common
for constraints to be empty.
Also, there's a bit of duplicated code in here that I have to check
before extracting.
Was surprising found that this example doesn't work:
scope :api do
resources :users
end
and the right form to use it is:
scope 'api' do
resources :users
end
I think this should work similary as `namespace` where both are allowed.
These two are equivalent:
namespace :api do
resources :users
end
namespace 'api' do
resources :user
end
Follow up of the discussion from the original merge commit:
f9cb645dfc (commitcomment-1414561)
We want to avoid people's mistakes with methods like count and sum when
called with a block, that can easily lead to code performing poorly and
that could be way better written with a db query.
Please check the discussion there for more background.
Closes#8268
Since edd94cee9af1688dd036fc58fd405adb30a5e0da, CollectionProxy
delegates all calculation methods - except count - to the scope,
which does basically what this method was doing, but since we're
delegating from the proxy, the association method was never called.
To perform a sum calculation over the array of elements, use to_a.sum(&block).
Please check the discussion in f9cb645dfcb5cc89f59d2f8b58a019486c828c73
for more context.
This reverts commit f9cb645dfcb5cc89f59d2f8b58a019486c828c73.
Conflicts:
activerecord/CHANGELOG.md
Revert "Allow blocks for count with ActiveRecord::Relation. Document and test that sum allows blocks"
This reverts commit 9cc2bf69ce296b7351dc612a8366193390a305f3.
Conflicts:
activerecord/lib/active_record/relation/calculations.rb
This improves memory and performance without having to use symbols which
present DoS problems. Thanks @headius and @tenderlove for the
suggestion.
This was originally committed in
f1765019ce9b6292f2264b4601dad5daaffe3a89, and then reverted in
d3494903719682abc0948bef290af0d3d7b5a440 due to it causing problems in a
real application. This second attempt should solve that.
Benchmark
---------
require 'active_record'
require 'benchmark/ips'
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
class Post < ActiveRecord::Base
connection.create_table :posts, force: true do |t|
t.string :name
end
end
post = Post.create name: 'omg'
Benchmark.ips do |r|
r.report('Post.new') { Post.new name: 'omg' }
r.report('post.name') { post.name }
r.report('post.name=') { post.name = 'omg' }
r.report('Post.find(1).name') { Post.find(1).name }
end
Before
------
Calculating -------------------------------------
Post.new 1419 i/100ms
post.name 7538 i/100ms
post.name= 3024 i/100ms
Post.find(1).name 243 i/100ms
-------------------------------------------------
Post.new 20637.6 (±12.7%) i/s - 102168 in 5.039578s
post.name 1167897.7 (±18.2%) i/s - 5186144 in 4.983077s
post.name= 64305.6 (±9.6%) i/s - 317520 in 4.998720s
Post.find(1).name 2678.8 (±10.8%) i/s - 13365 in 5.051265s
After
-----
Calculating -------------------------------------
Post.new 1431 i/100ms
post.name 7790 i/100ms
post.name= 3181 i/100ms
Post.find(1).name 245 i/100ms
-------------------------------------------------
Post.new 21308.8 (±12.2%) i/s - 105894 in 5.053879s
post.name 1534103.8 (±2.1%) i/s - 7634200 in 4.979405s
post.name= 67441.0 (±7.5%) i/s - 337186 in 5.037871s
Post.find(1).name 2681.9 (±10.6%) i/s - 13475 in 5.084511s
