debian-mirror-gitlab/app/finders/snippets_finder.rb
2020-08-09 17:44:08 +05:30

224 lines
6.1 KiB
Ruby

# frozen_string_literal: true
# Finder for retrieving snippets that a user can see, optionally scoped to a
# project or snippets author.
#
# Basic usage:
#
# user = User.find(1)
#
# SnippetsFinder.new(user).execute
#
# To limit the snippets to a specific project, supply the `project:` option:
#
# user = User.find(1)
# project = Project.find(1)
#
# SnippetsFinder.new(user, project: project).execute
#
# Limiting snippets to an author can be done by supplying the `author:` option:
#
# user = User.find(1)
# project = Project.find(1)
#
# SnippetsFinder.new(user, author: user).execute
#
# To filter snippets using a specific visibility level, you can provide the
# `scope:` option:
#
# user = User.find(1)
# project = Project.find(1)
#
# SnippetsFinder.new(user, author: user, scope: :are_public).execute
#
# Valid `scope:` values are:
#
# * `:are_private`
# * `:are_internal`
# * `:are_public`
#
# Any other value will be ignored.
class SnippetsFinder < UnionFinder
include FinderMethods
include Gitlab::Utils::StrongMemoize
attr_accessor :current_user, :params
delegate :explore, :only_personal, :only_project, :scope, :sort, to: :params
def initialize(current_user = nil, params = {})
@current_user = current_user
@params = OpenStruct.new(params)
if project && author
raise(
ArgumentError,
'Filtering by both an author and a project is not supported, ' \
'as this finder is not optimised for this use case'
)
end
end
def execute
# The snippet query can be expensive, therefore if the
# author or project params have been passed and they don't
# exist, or if a Project has been passed and has snippets
# disabled, it's better to return
return Snippet.none if author.nil? && params[:author].present?
return Snippet.none if project.nil? && params[:project].present?
return Snippet.none if project && !project.feature_available?(:snippets, current_user)
items = init_collection
items = by_ids(items)
items = items.with_optional_visibility(visibility_from_scope)
items.order_by(sort_param)
end
private
def init_collection
if explore
snippets_for_explore
elsif only_personal
personal_snippets
elsif project
snippets_for_a_single_project
else
snippets_for_personal_and_multiple_projects
end
end
# Produces a query that retrieves snippets for the Explore page
#
# We only show personal snippets here because this page is meant for
# discovery, and project snippets are of limited interest here.
def snippets_for_explore
Snippet.public_to_user(current_user).only_personal_snippets
end
# Produces a query that retrieves snippets from multiple projects.
#
# The resulting query will, depending on the user's permissions, include the
# following collections of snippets:
#
# 1. Snippets that don't belong to any project.
# 2. Snippets of projects that are visible to the current user (e.g. snippets
# in public projects).
# 3. Snippets of projects that the current user is a member of.
#
# Each collection is constructed in isolation, allowing for greater control
# over the resulting SQL query.
def snippets_for_personal_and_multiple_projects
queries = []
queries << personal_snippets unless only_project
if Ability.allowed?(current_user, :read_cross_project)
queries << snippets_of_visible_projects
queries << snippets_of_authorized_projects if current_user
end
prepared_union(queries)
end
def snippets_for_a_single_project
Snippet.for_project_with_user(project, current_user)
end
def personal_snippets
snippets_for_author_or_visible_to_user.only_personal_snippets
end
# Returns the snippets that the current user (logged in or not) can view.
def snippets_of_visible_projects
snippets_for_author_or_visible_to_user
.only_include_projects_visible_to(current_user)
.only_include_projects_with_snippets_enabled
end
# Returns the snippets that the currently logged in user has access to by
# being a member of the project the snippets belong to.
#
# This method requires that `current_user` returns a `User` instead of `nil`,
# and is optimised for this specific scenario.
def snippets_of_authorized_projects
base = author ? author.snippets : Snippet.all
base
.only_include_projects_with_snippets_enabled(include_private: true)
.only_include_authorized_projects(current_user)
end
def snippets_for_author_or_visible_to_user
if author
snippets_for_author
elsif current_user
Snippet.visible_to_or_authored_by(current_user)
else
Snippet.public_to_user
end
end
def snippets_for_author
base = author.snippets
if author == current_user
# If the current user is also the author of all snippets, then we can
# include private snippets.
base
else
base.public_to_user(current_user)
end
end
def visibility_from_scope
case scope.to_s
when 'are_private'
Snippet::PRIVATE
when 'are_internal'
Snippet::INTERNAL
when 'are_public'
Snippet::PUBLIC
else
nil
end
end
def by_ids(items)
return items unless params[:ids].present?
items.id_in(params[:ids])
end
def author
strong_memoize(:author) do
next unless params[:author].present?
params[:author].is_a?(User) ? params[:author] : User.find_by_id(params[:author])
end
end
def project
strong_memoize(:project) do
next unless params[:project].present?
params[:project].is_a?(Project) ? params[:project] : Project.find_by_id(params[:project])
end
end
def sort_param
sort.presence || 'id_desc'
end
def prepared_union(queries)
return Snippet.none if queries.empty?
return queries.first if queries.length == 1
# The queries are going to be part of a global `where`
# therefore we only need to retrieve the `id` column
# which will speed the query
queries.map! { |rel| rel.select(:id) }
Snippet.id_in(find_union(queries, Snippet))
end
end
SnippetsFinder.prepend_if_ee('EE::SnippetsFinder')