debian-mirror-gitlab/lib/gitlab/project_authorizations/with_nested_groups.rb
2018-12-23 12:14:25 +05:30

125 lines
4.1 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module ProjectAuthorizations
# Calculating new project authorizations when supporting nested groups.
#
# This class relies on Common Table Expressions to efficiently get all data,
# including data for nested groups. As a result this class can only be used
# on PostgreSQL.
class WithNestedGroups
attr_reader :user
# user - The User object for which to calculate the authorizations.
def initialize(user)
@user = user
end
def calculate
cte = recursive_cte
cte_alias = cte.table.alias(Group.table_name)
projects = Project.arel_table
links = ProjectGroupLink.arel_table
relations = [
# The project a user has direct access to.
user.projects.select_for_project_authorization,
# The personal projects of the user.
user.personal_projects.select_as_maintainer_for_project_authorization,
# Projects that belong directly to any of the groups the user has
# access to.
Namespace
.unscoped
.select([alias_as_column(projects[:id], 'project_id'),
cte_alias[:access_level]])
.from(cte_alias)
.joins(:projects),
# Projects shared with any of the namespaces the user has access to.
Namespace
.unscoped
.select([links[:project_id],
least(cte_alias[:access_level],
links[:group_access],
'access_level')])
.from(cte_alias)
.joins('INNER JOIN project_group_links ON project_group_links.group_id = namespaces.id')
.joins('INNER JOIN projects ON projects.id = project_group_links.project_id')
.joins('INNER JOIN namespaces p_ns ON p_ns.id = projects.namespace_id')
.where('p_ns.share_with_group_lock IS FALSE')
]
ProjectAuthorization
.unscoped
.with
.recursive(cte.to_arel)
.select_from_union(relations)
end
private
# Builds a recursive CTE that gets all the groups the current user has
# access to, including any nested groups.
def recursive_cte
cte = Gitlab::SQL::RecursiveCTE.new(:namespaces_cte)
members = Member.arel_table
namespaces = Namespace.arel_table
# Namespaces the user is a member of.
cte << user.groups
.select([namespaces[:id], members[:access_level]])
.except(:order)
# Sub groups of any groups the user is a member of.
cte << Group.select([namespaces[:id],
greatest(members[:access_level],
cte.table[:access_level], 'access_level')])
.joins(join_cte(cte))
.joins(join_members)
.except(:order)
cte
end
# Builds a LEFT JOIN to join optional memberships onto the CTE.
def join_members
members = Member.arel_table
namespaces = Namespace.arel_table
cond = members[:source_id]
.eq(namespaces[:id])
.and(members[:source_type].eq('Namespace'))
.and(members[:requested_at].eq(nil))
.and(members[:user_id].eq(user.id))
Arel::Nodes::OuterJoin.new(members, Arel::Nodes::On.new(cond))
end
# Builds an INNER JOIN to join namespaces onto the CTE.
def join_cte(cte)
namespaces = Namespace.arel_table
cond = cte.table[:id].eq(namespaces[:parent_id])
Arel::Nodes::InnerJoin.new(cte.table, Arel::Nodes::On.new(cond))
end
def greatest(left, right, column_alias)
sql_function('GREATEST', [left, right], column_alias)
end
def least(left, right, column_alias)
sql_function('LEAST', [left, right], column_alias)
end
def sql_function(name, args, column_alias)
alias_as_column(Arel::Nodes::NamedFunction.new(name, args), column_alias)
end
def alias_as_column(value, alias_to)
Arel::Nodes::As.new(value, Arel::Nodes::SqlLiteral.new(alias_to))
end
end
end
end