gitlab-org--gitlab-foss/spec/models/snippet_spec.rb
Yorick Peterse d171ff6016
Rewrite SnippetsFinder to improve performance
This completely rewrites the SnippetsFinder class from the ground up in
order to improve its performance. The old code was beyond salvaging. It
was complex, included various Rails 5 workarounds, comments that
shouldn't be necessary, and most important of all: it produced a really
poorly performing database query.

As a result, I opted for rewriting the finder from scratch, instead of
trying to patch the existing code. Instead of trying to reuse as many
existing methods as possible, I opted for defining new methods
specifically meant for the SnippetsFinder. This requires some extra code
here and there, but allows us to have much more control over the
resulting SQL queries. It is these changes that then allow us to produce
a _much_ more efficient query.

To illustrate how bad the old query was, we will use my own snippets as
an example. Currently I have 52 snippets, most of which are global ones.
To retrieve these, you would run the following Ruby code:

    user = User.find_by(username: 'yorickpeterse')

    SnippetsFinder.new(user, author: user).execute

On GitLab.com the resulting query will take between 10 and 15 seconds to
run, producing the query plan found at
https://explain.depesz.com/s/Y5IX. Apart from the long execution time,
the total number of buffers (the sum of all shared hits) is around 185
GB, though the real number is probably (hopefully) much lower as I doubt
simply summing these numbers produces the true total number of buffers
used.

The new query's plan can be found at https://explain.depesz.com/s/wHdN,
and this query takes between 10 and 100-ish milliseconds to run. The
total number of buffers used is only about 30 MB.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/52639
2018-11-05 14:28:29 +01:00

426 lines
13 KiB
Ruby

require 'spec_helper'
describe Snippet do
describe 'modules' do
subject { described_class }
it { is_expected.to include_module(Gitlab::VisibilityLevel) }
it { is_expected.to include_module(Participable) }
it { is_expected.to include_module(Referable) }
it { is_expected.to include_module(Sortable) }
it { is_expected.to include_module(Awardable) }
end
describe 'associations' do
it { is_expected.to belong_to(:author).class_name('User') }
it { is_expected.to belong_to(:project) }
it { is_expected.to have_many(:notes).dependent(:destroy) }
it { is_expected.to have_many(:award_emoji).dependent(:destroy) }
end
describe 'validation' do
it { is_expected.to validate_presence_of(:author) }
it { is_expected.to validate_presence_of(:title) }
it { is_expected.to validate_length_of(:title).is_at_most(255) }
it { is_expected.to validate_length_of(:file_name).is_at_most(255) }
it { is_expected.to validate_presence_of(:content) }
it { is_expected.to validate_inclusion_of(:visibility_level).in_array(Gitlab::VisibilityLevel.values) }
end
describe '#to_reference' do
context 'when snippet belongs to a project' do
let(:project) { build(:project, name: 'sample-project') }
let(:snippet) { build(:snippet, id: 1, project: project) }
it 'returns a String reference to the object' do
expect(snippet.to_reference).to eq "$1"
end
it 'supports a cross-project reference' do
another_project = build(:project, name: 'another-project', namespace: project.namespace)
expect(snippet.to_reference(another_project)).to eq "sample-project$1"
end
end
context 'when snippet does not belong to a project' do
let(:snippet) { build(:snippet, id: 1, project: nil) }
it 'returns a String reference to the object' do
expect(snippet.to_reference).to eq "$1"
end
it 'still returns shortest reference when project arg present' do
another_project = build(:project, name: 'another-project')
expect(snippet.to_reference(another_project)).to eq "$1"
end
end
end
describe '#file_name' do
let(:project) { create(:project) }
context 'file_name is nil' do
let(:snippet) { create(:snippet, project: project, file_name: nil) }
it 'returns an empty string' do
expect(snippet.file_name).to eq ''
end
end
context 'file_name is not nil' do
let(:snippet) { create(:snippet, project: project, file_name: 'foo.txt') }
it 'returns the file_name' do
expect(snippet.file_name).to eq 'foo.txt'
end
end
end
describe "#content_html_invalidated?" do
let(:snippet) { create(:snippet, content: "md", content_html: "html", file_name: "foo.md") }
it "invalidates the HTML cache of content when the filename changes" do
expect { snippet.file_name = "foo.rb" }.to change { snippet.content_html_invalidated? }.from(false).to(true)
end
end
describe '.search' do
let(:snippet) { create(:snippet, title: 'test snippet') }
it 'returns snippets with a matching title' do
expect(described_class.search(snippet.title)).to eq([snippet])
end
it 'returns snippets with a partially matching title' do
expect(described_class.search(snippet.title[0..2])).to eq([snippet])
end
it 'returns snippets with a matching title regardless of the casing' do
expect(described_class.search(snippet.title.upcase)).to eq([snippet])
end
it 'returns snippets with a matching file name' do
expect(described_class.search(snippet.file_name)).to eq([snippet])
end
it 'returns snippets with a partially matching file name' do
expect(described_class.search(snippet.file_name[0..2])).to eq([snippet])
end
it 'returns snippets with a matching file name regardless of the casing' do
expect(described_class.search(snippet.file_name.upcase)).to eq([snippet])
end
end
describe '.search_code' do
let(:snippet) { create(:snippet, content: 'class Foo; end') }
it 'returns snippets with matching content' do
expect(described_class.search_code(snippet.content)).to eq([snippet])
end
it 'returns snippets with partially matching content' do
expect(described_class.search_code('class')).to eq([snippet])
end
it 'returns snippets with matching content regardless of the casing' do
expect(described_class.search_code('FOO')).to eq([snippet])
end
end
describe '.with_optional_visibility' do
context 'when a visibility level is provided' do
it 'returns snippets with the given visibility' do
create(:snippet, :private)
snippet = create(:snippet, :public)
snippets = described_class
.with_optional_visibility(Gitlab::VisibilityLevel::PUBLIC)
expect(snippets).to eq([snippet])
end
end
context 'when a visibility level is not provided' do
it 'returns all snippets' do
snippet1 = create(:snippet, :public)
snippet2 = create(:snippet, :private)
snippets = described_class.with_optional_visibility
expect(snippets).to include(snippet1, snippet2)
end
end
end
describe '.only_global_snippets' do
it 'returns snippets not associated with any projects' do
create(:project_snippet)
snippet = create(:snippet)
snippets = described_class.only_global_snippets
expect(snippets).to eq([snippet])
end
end
describe '.only_include_projects_visible_to' do
let!(:project1) { create(:project, :public) }
let!(:project2) { create(:project, :internal) }
let!(:project3) { create(:project, :private) }
let!(:snippet1) { create(:project_snippet, project: project1) }
let!(:snippet2) { create(:project_snippet, project: project2) }
let!(:snippet3) { create(:project_snippet, project: project3) }
context 'when a user is provided' do
it 'returns snippets visible to the user' do
user = create(:user)
snippets = described_class.only_include_projects_visible_to(user)
expect(snippets).to include(snippet1, snippet2)
expect(snippets).not_to include(snippet3)
end
end
context 'when a user is not provided' do
it 'returns snippets visible to anonymous users' do
snippets = described_class.only_include_projects_visible_to
expect(snippets).to include(snippet1)
expect(snippets).not_to include(snippet2, snippet3)
end
end
end
describe 'only_include_projects_with_snippets_enabled' do
context 'when the include_private option is enabled' do
it 'includes snippets for projects with snippets set to private' do
project = create(:project)
project.project_feature
.update(snippets_access_level: ProjectFeature::PRIVATE)
snippet = create(:project_snippet, project: project)
snippets = described_class
.only_include_projects_with_snippets_enabled(include_private: true)
expect(snippets).to eq([snippet])
end
end
context 'when the include_private option is not enabled' do
it 'does not include snippets for projects that have snippets set to private' do
project = create(:project)
project.project_feature
.update(snippets_access_level: ProjectFeature::PRIVATE)
create(:project_snippet, project: project)
snippets = described_class.only_include_projects_with_snippets_enabled
expect(snippets).to be_empty
end
end
it 'includes snippets for projects with snippets enabled' do
project = create(:project)
project.project_feature
.update(snippets_access_level: ProjectFeature::ENABLED)
snippet = create(:project_snippet, project: project)
snippets = described_class.only_include_projects_with_snippets_enabled
expect(snippets).to eq([snippet])
end
end
describe '.only_include_authorized_projects' do
it 'only includes snippets for projects the user is authorized to see' do
user = create(:user)
project1 = create(:project, :private)
project2 = create(:project, :private)
project1.team.add_developer(user)
create(:project_snippet, project: project2)
snippet = create(:project_snippet, project: project1)
snippets = described_class.only_include_authorized_projects(user)
expect(snippets).to eq([snippet])
end
end
describe '.for_project_with_user' do
context 'when a user is provided' do
it 'returns an empty collection if the user can not view the snippets' do
project = create(:project, :private)
user = create(:user)
project.project_feature
.update(snippets_access_level: ProjectFeature::ENABLED)
create(:project_snippet, :public, project: project)
expect(described_class.for_project_with_user(project, user)).to be_empty
end
it 'returns the snippets if the user is a member of the project' do
project = create(:project, :private)
user = create(:user)
snippet = create(:project_snippet, project: project)
project.team.add_developer(user)
snippets = described_class.for_project_with_user(project, user)
expect(snippets).to eq([snippet])
end
it 'returns public snippets for a public project the user is not a member of' do
project = create(:project, :public)
project.project_feature
.update(snippets_access_level: ProjectFeature::ENABLED)
user = create(:user)
snippet = create(:project_snippet, :public, project: project)
create(:project_snippet, :private, project: project)
snippets = described_class.for_project_with_user(project, user)
expect(snippets).to eq([snippet])
end
end
context 'when a user is not provided' do
it 'returns an empty collection for a private project' do
project = create(:project, :private)
project.project_feature
.update(snippets_access_level: ProjectFeature::ENABLED)
create(:project_snippet, :public, project: project)
expect(described_class.for_project_with_user(project)).to be_empty
end
it 'returns public snippets for a public project' do
project = create(:project, :public)
snippet = create(:project_snippet, :public, project: project)
project.project_feature
.update(snippets_access_level: ProjectFeature::PUBLIC)
create(:project_snippet, :private, project: project)
snippets = described_class.for_project_with_user(project)
expect(snippets).to eq([snippet])
end
end
end
describe '.visible_to_or_authored_by' do
it 'returns snippets visible to the user' do
user = create(:user)
snippet1 = create(:snippet, :public)
snippet2 = create(:snippet, :private, author: user)
snippet3 = create(:snippet, :private)
snippets = described_class.visible_to_or_authored_by(user)
expect(snippets).to include(snippet1, snippet2)
expect(snippets).not_to include(snippet3)
end
end
describe '#participants' do
let(:project) { create(:project, :public) }
let(:snippet) { create(:snippet, content: 'foo', project: project) }
let!(:note1) do
create(:note_on_project_snippet,
noteable: snippet,
project: project,
note: 'a')
end
let!(:note2) do
create(:note_on_project_snippet,
noteable: snippet,
project: project,
note: 'b')
end
it 'includes the snippet author' do
expect(snippet.participants).to include(snippet.author)
end
it 'includes the note authors' do
expect(snippet.participants).to include(note1.author, note2.author)
end
end
describe '#check_for_spam' do
let(:snippet) { create :snippet, visibility_level: visibility_level }
subject do
snippet.assign_attributes(title: title)
snippet.check_for_spam?
end
context 'when public and spammable attributes changed' do
let(:visibility_level) { Snippet::PUBLIC }
let(:title) { 'woo' }
it 'returns true' do
is_expected.to be_truthy
end
end
context 'when private' do
let(:visibility_level) { Snippet::PRIVATE }
let(:title) { snippet.title }
it 'returns false' do
is_expected.to be_falsey
end
it 'returns true when switching to public' do
snippet.save!
snippet.visibility_level = Snippet::PUBLIC
expect(snippet.check_for_spam?).to be_truthy
end
end
context 'when spammable attributes have not changed' do
let(:visibility_level) { Snippet::PUBLIC }
let(:title) { snippet.title }
it 'returns false' do
is_expected.to be_falsey
end
end
end
describe '#blob' do
let(:snippet) { create(:snippet) }
it 'returns a blob representing the snippet data' do
blob = snippet.blob
expect(blob).to be_a(Blob)
expect(blob.path).to eq(snippet.file_name)
expect(blob.data).to eq(snippet.content)
end
end
end