Commit 3f1c24ce authored by Sean McGivern's avatar Sean McGivern

Merge branch 'tags-api-performance' into 'master'

API JSON caching for tags endpoint [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!54975
parents 75caa70f 59ea5786
......@@ -4,7 +4,7 @@ module ProtectedRef
extend ActiveSupport::Concern
included do
belongs_to :project
belongs_to :project, touch: true
validates :name, presence: true
validates :project, presence: true
......
......@@ -8,7 +8,7 @@ class Release < ApplicationRecord
cache_markdown_field :description
belongs_to :project
belongs_to :project, touch: true
# releases prior to 11.7 have no author
belongs_to :author, class_name: 'User'
......
---
title: API JSON caching for tags endpoint
merge_request: 54975
author:
type: performance
---
name: api_caching_tags
introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/54975
rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/324391
milestone: '13.10'
type: development
group: group::source code
default_enabled: false
......@@ -3,6 +3,7 @@
module API
module Helpers
include Gitlab::Utils
include Helpers::Caching
include Helpers::Pagination
include Helpers::PaginationStrategies
......
# frozen_string_literal: true
# Grape helpers for caching.
#
# This module helps introduce standardised caching into the Grape API
# in a similar manner to the standard Grape DSL.
module API
module Helpers
module Caching
# @return [ActiveSupport::Duration]
DEFAULT_EXPIRY = 1.day
# @return [ActiveSupport::Cache::Store]
def cache
Rails.cache
end
# This is functionally equivalent to the standard `#present` used in
# Grape endpoints, but the JSON for the object, or for each object of
# a collection, will be cached.
#
# With a collection all the keys will be fetched in a single call and the
# Entity rendered for those missing from the cache, which are then written
# back into it.
#
# Both the single object, and all objects inside a collection, must respond
# to `#cache_key`.
#
# To override the Grape formatter we return a custom wrapper in
# `Gitlab::Json::PrecompiledJson` which tells the `Gitlab::Json::GrapeFormatter`
# to export the string without conversion.
#
# A cache context can be supplied to add more context to the cache key. This
# defaults to including the `current_user` in every key for safety, unless overridden.
#
# @param obj_or_collection [Object, Enumerable<Object>] the object or objects to render
# @param with [Grape::Entity] the entity to use for rendering
# @param cache_context [Proc] a proc to call for each object to provide more context to the cache key
# @param expires_in [ActiveSupport::Duration, Integer] an expiry time for the cache entry
# @param presenter_args [Hash] keyword arguments to be passed to the entity
# @return [Gitlab::Json::PrecompiledJson]
def present_cached(obj_or_collection, with:, cache_context: -> (_) { current_user.cache_key }, expires_in: DEFAULT_EXPIRY, **presenter_args)
json =
if obj_or_collection.is_a?(Enumerable)
cached_collection(
obj_or_collection,
presenter: with,
presenter_args: presenter_args,
context: cache_context,
expires_in: expires_in
)
else
cached_object(
obj_or_collection,
presenter: with,
presenter_args: presenter_args,
context: cache_context,
expires_in: expires_in
)
end
body Gitlab::Json::PrecompiledJson.new(json)
end
private
# Optionally uses a `Proc` to add context to a cache key
#
# @param object [Object] must respond to #cache_key
# @param context [Proc] a proc that will be called with the object as an argument, and which should return a
# string or array of strings to be combined into the cache key
# @return [String]
def contextual_cache_key(object, context)
return object.cache_key if context.nil?
[object.cache_key, context.call(object)].flatten.join(":")
end
# Used for fetching or rendering a single object
#
# @param object [Object] the object to render
# @param presenter [Grape::Entity]
# @param presenter_args [Hash] keyword arguments to be passed to the entity
# @param context [Proc]
# @param expires_in [ActiveSupport::Duration, Integer] an expiry time for the cache entry
# @return [String]
def cached_object(object, presenter:, presenter_args:, context:, expires_in:)
cache.fetch(contextual_cache_key(object, context), expires_in: expires_in) do
Gitlab::Json.dump(presenter.represent(object, **presenter_args).as_json)
end
end
# Used for fetching or rendering multiple objects
#
# @param objects [Enumerable<Object>] the objects to render
# @param presenter [Grape::Entity]
# @param presenter_args [Hash] keyword arguments to be passed to the entity
# @param context [Proc]
# @param expires_in [ActiveSupport::Duration, Integer] an expiry time for the cache entry
# @return [Array<String>]
def cached_collection(collection, presenter:, presenter_args:, context:, expires_in:)
json = fetch_multi(collection, context: context, expires_in: expires_in) do |obj|
Gitlab::Json.dump(presenter.represent(obj, **presenter_args).as_json)
end
json.values
end
# An adapted version of ActiveSupport::Cache::Store#fetch_multi.
#
# The original method only provides the missing key to the block,
# not the missing object, so we have to create a map of cache keys
# to the objects to allow us to pass the object to the missing value
# block.
#
# The result is that this is functionally identical to `#fetch`.
def fetch_multi(*objs, context:, **kwargs)
objs.flatten!
map = multi_key_map(objs, context: context)
cache.fetch_multi(*map.keys, **kwargs) do |key|
yield map[key]
end
end
# @param objects [Enumerable<Object>] objects which _must_ respond to `#cache_key`
# @param context [Proc] a proc that can be called to help generate each cache key
# @return [Hash]
def multi_key_map(objects, context:)
objects.index_by do |object|
contextual_cache_key(object, context)
end
end
end
end
end
......@@ -28,7 +28,13 @@ module API
sort: "#{params[:order_by]}_#{params[:sort]}",
search: params[:search]).execute
present paginate(::Kaminari.paginate_array(tags)), with: Entities::Tag, project: user_project
paginated_tags = paginate(::Kaminari.paginate_array(tags))
if Feature.enabled?(:api_caching_tags, user_project, type: :development)
present_cached paginated_tags, with: Entities::Tag, project: user_project, cache_context: -> (_tag) { user_project.cache_key }
else
present paginated_tags, with: Entities::Tag, project: user_project
end
end
desc 'Get a single repository tag' do
......
......@@ -87,6 +87,10 @@ module Gitlab
end
end
def cache_key
"tag:" + Digest::SHA1.hexdigest([name, message, target, target_commit&.sha].join)
end
private
def message_from_gitaly_tag
......
......@@ -186,9 +186,14 @@ module Gitlab
# The `env` param is ignored because it's not needed in either our formatter or Grape's,
# but it is passed through for consistency.
#
# If explicitly supplied with a `PrecompiledJson` instance it will skip conversion
# and return it directly. This is mostly used in caching.
#
# @param object [Object]
# @return [String]
def self.call(object, env = nil)
return object.to_s if object.is_a?(PrecompiledJson)
if Feature.enabled?(:grape_gitlab_json, default_enabled: true)
Gitlab::Json.dump(object)
else
......@@ -197,6 +202,34 @@ module Gitlab
end
end
# Wrapper class used to skip JSON dumping on Grape endpoints.
class PrecompiledJson
UnsupportedFormatError = Class.new(StandardError)
# @overload PrecompiledJson.new("foo")
# @param value [String]
#
# @overload PrecompiledJson.new(["foo", "bar"])
# @param value [Array<String>]
def initialize(value)
@value = value
end
# Convert the value to a String. This will invoke
# `#to_s` on the members of the value if it's an array.
#
# @return [String]
# @raise [NoMethodError] if the objects in an array doesn't support to_s
# @raise [PrecompiledJson::UnsupportedFormatError] if the value is neither a String or Array
def to_s
return @value if @value.is_a?(String)
return "[#{@value.join(',')}]" if @value.is_a?(Array)
raise UnsupportedFormatError
end
end
class LimitedEncoder
LimitExceeded = Class.new(StandardError)
......
......@@ -65,14 +65,23 @@ RSpec.describe 'factories' do
# associations must be unique and cannot be reused, or the factory default
# is being mutated.
skip_factory_defaults = %i[
evidence
exported_protected_branch
fork_network_member
group_member
import_state
milestone_release
namespace
project_broken_repo
prometheus_alert
prometheus_alert_event
prometheus_metric
protected_branch
protected_branch_merge_access_level
protected_branch_push_access_level
protected_tag
release
release_link
self_managed_prometheus_alert_event
users_star_project
wiki_page
......
# frozen_string_literal: true
require "spec_helper"
RSpec.describe API::Helpers::Caching do
subject(:instance) { Class.new.include(described_class).new }
describe "#present_cached" do
let_it_be(:project) { create(:project) }
let_it_be(:user) { create(:user) }
let(:presenter) { API::Entities::Todo }
let(:kwargs) do
{
with: presenter,
project: project
}
end
subject do
instance.present_cached(presentable, **kwargs)
end
before do
# We have to stub #body as it's a Grape method
# unavailable in the module by itself
expect(instance).to receive(:body) do |data|
data
end
allow(instance).to receive(:current_user) { user }
end
context "single object" do
let_it_be(:presentable) { create(:todo, project: project) }
it { is_expected.to be_a(Gitlab::Json::PrecompiledJson) }
it "uses the presenter" do
expect(presenter).to receive(:represent).with(presentable, project: project)
subject
end
it "is valid JSON" do
parsed = Gitlab::Json.parse(subject.to_s)
expect(parsed).to be_a(Hash)
expect(parsed["id"]).to eq(presentable.id)
end
it "fetches from the cache" do
expect(instance.cache).to receive(:fetch).with("#{presentable.cache_key}:#{user.cache_key}", expires_in: described_class::DEFAULT_EXPIRY).once
subject
end
context "when a cache context is supplied" do
before do
kwargs[:cache_context] = -> (todo) { todo.project.cache_key }
end
it "uses the context to augment the cache key" do
expect(instance.cache).to receive(:fetch).with("#{presentable.cache_key}:#{project.cache_key}", expires_in: described_class::DEFAULT_EXPIRY).once
subject
end
end
context "when expires_in is supplied" do
it "sets the expiry when accessing the cache" do
kwargs[:expires_in] = 7.days
expect(instance.cache).to receive(:fetch).with("#{presentable.cache_key}:#{user.cache_key}", expires_in: 7.days).once
subject
end
end
end
context "for a collection of objects" do
let_it_be(:presentable) { Array.new(5).map { create(:todo, project: project) } }
it { is_expected.to be_an(Gitlab::Json::PrecompiledJson) }
it "uses the presenter" do
presentable.each do |todo|
expect(presenter).to receive(:represent).with(todo, project: project)
end
subject
end
it "is valid JSON" do
parsed = Gitlab::Json.parse(subject.to_s)
expect(parsed).to be_an(Array)
presentable.each_with_index do |todo, i|
expect(parsed[i]["id"]).to eq(todo.id)
end
end
it "fetches from the cache" do
keys = presentable.map { |todo| "#{todo.cache_key}:#{user.cache_key}" }
expect(instance.cache).to receive(:fetch_multi).with(*keys, expires_in: described_class::DEFAULT_EXPIRY).once.and_call_original
subject
end
context "when a cache context is supplied" do
before do
kwargs[:cache_context] = -> (todo) { todo.project.cache_key }
end
it "uses the context to augment the cache key" do
keys = presentable.map { |todo| "#{todo.cache_key}:#{project.cache_key}" }
expect(instance.cache).to receive(:fetch_multi).with(*keys, expires_in: described_class::DEFAULT_EXPIRY).once.and_call_original
subject
end
end
context "expires_in is supplied" do
it "sets the expiry when accessing the cache" do
keys = presentable.map { |todo| "#{todo.cache_key}:#{user.cache_key}" }
kwargs[:expires_in] = 7.days
expect(instance.cache).to receive(:fetch_multi).with(*keys, expires_in: 7.days).once.and_call_original
subject
end
end
end
end
end
......@@ -101,4 +101,17 @@ RSpec.describe Gitlab::Git::Tag, :seed_helper do
end
end
end
describe "#cache_key" do
subject { repository.tags.first }
it "returns a cache key that changes based on changeable values" do
expect(subject).to receive(:name).and_return("v1.0.0")
expect(subject).to receive(:message).and_return("Initial release")
digest = Digest::SHA1.hexdigest(["v1.0.0", "Initial release", subject.target, subject.target_commit.sha].join)
expect(subject.cache_key).to eq("tag:#{digest}")
end
end
end
......@@ -348,6 +348,66 @@ RSpec.describe Gitlab::Json do
subject
end
end
context "precompiled JSON" do
let(:obj) { Gitlab::Json::PrecompiledJson.new(result) }
it "renders the string directly" do
expect(subject).to eq(result)
end
it "calls #to_s on the object" do
expect(obj).to receive(:to_s).once
subject
end
it "doesn't run the JSON formatter" do
expect(Gitlab::Json).not_to receive(:dump)
subject
end
end
end
describe Gitlab::Json::PrecompiledJson do
subject(:precompiled) { described_class.new(obj) }
describe "#to_s" do
subject { precompiled.to_s }
context "obj is a string" do
let(:obj) { "{}" }
it "returns a string" do
expect(subject).to eq("{}")
end
end
context "obj is an array" do
let(:obj) { ["{\"foo\": \"bar\"}", "{}"] }
it "returns a string" do
expect(subject).to eq("[{\"foo\": \"bar\"},{}]")
end
end
context "obj is an array of un-stringables" do
let(:obj) { [BasicObject.new] }
it "raises an error" do
expect { subject }.to raise_error(NoMethodError)
end
end
context "obj is something else" do
let(:obj) { {} }
it "raises an error" do
expect { subject }.to raise_error(described_class::UnsupportedFormatError)
end
end
end
end
describe Gitlab::Json::LimitedEncoder do
......
......@@ -4,7 +4,7 @@ require 'spec_helper'
RSpec.describe ProtectedTag do
describe 'Associations' do
it { is_expected.to belong_to(:project) }
it { is_expected.to belong_to(:project).touch(true) }
end
describe 'Validation' do
......
......@@ -10,7 +10,7 @@ RSpec.describe Release do
it { expect(release).to be_valid }
describe 'associations' do
it { is_expected.to belong_to(:project) }
it { is_expected.to belong_to(:project).touch(true) }
it { is_expected.to belong_to(:author).class_name('User') }
it { is_expected.to have_many(:links).class_name('Releases::Link') }
it { is_expected.to have_many(:milestones) }
......
......@@ -17,6 +17,7 @@ RSpec.describe API::Tags do
end
describe 'GET /projects/:id/repository/tags' do
shared_examples "get repository tags" do
let(:route) { "/projects/#{project_id}/repository/tags" }
context 'sorting' do
......@@ -144,6 +145,71 @@ RSpec.describe API::Tags do
end
end
context ":api_caching_tags flag enabled", :use_clean_rails_memory_store_caching do
before do
stub_feature_flags(api_caching_tags: true)
end
it_behaves_like "get repository tags"
describe "cache expiry" do
let(:route) { "/projects/#{project_id}/repository/tags" }
let(:current_user) { user }
before do
# Set the cache
get api(route, current_user)
end
it "is cached" do
expect(API::Entities::Tag).not_to receive(:represent)
get api(route, current_user)
end
shared_examples "cache expired" do
it "isn't cached" do
expect(API::Entities::Tag).to receive(:represent).exactly(3).times
get api(route, current_user)
end
end
context "when protected tag is changed" do
before do
create(:protected_tag, name: tag_name, project: project)
end
it_behaves_like "cache expired"
end
context "when release is changed" do
before do
create(:release, :legacy, project: project, tag: tag_name)
end
it_behaves_like "cache expired"
end
context "when project is changed" do
before do
project.touch
end
it_behaves_like "cache expired"
end
end
end
context ":api_caching_tags flag disabled" do
before do
stub_feature_flags(api_caching_tags: false)
end
it_behaves_like "get repository tags"
end
end
describe 'GET /projects/:id/repository/tags/:tag_name' do
let(:route) { "/projects/#{project_id}/repository/tags/#{tag_name}" }
......
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