34974258bc
This hides/disables some UI elements and API parameters related to nested groups when MySQL is used, since nested groups are not supported for MySQL.
104 lines
2.8 KiB
Ruby
104 lines
2.8 KiB
Ruby
module Gitlab
|
|
# Retrieving of parent or child groups based on a base ActiveRecord relation.
|
|
#
|
|
# This class uses recursive CTEs and as a result will only work on PostgreSQL.
|
|
class GroupHierarchy
|
|
attr_reader :base, :model
|
|
|
|
# base - An instance of ActiveRecord::Relation for which to get parent or
|
|
# child groups.
|
|
def initialize(base)
|
|
@base = base
|
|
@model = base.model
|
|
end
|
|
|
|
# Returns a relation that includes the base set of groups and all their
|
|
# ancestors (recursively).
|
|
def base_and_ancestors
|
|
return model.none unless Group.supports_nested_groups?
|
|
|
|
base_and_ancestors_cte.apply_to(model.all)
|
|
end
|
|
|
|
# Returns a relation that includes the base set of groups and all their
|
|
# descendants (recursively).
|
|
def base_and_descendants
|
|
return model.none unless Group.supports_nested_groups?
|
|
|
|
base_and_descendants_cte.apply_to(model.all)
|
|
end
|
|
|
|
# Returns a relation that includes the base groups, their ancestors, and the
|
|
# descendants of the base groups.
|
|
#
|
|
# The resulting query will roughly look like the following:
|
|
#
|
|
# WITH RECURSIVE ancestors AS ( ... ),
|
|
# descendants AS ( ... )
|
|
# SELECT *
|
|
# FROM (
|
|
# SELECT *
|
|
# FROM ancestors namespaces
|
|
#
|
|
# UNION
|
|
#
|
|
# SELECT *
|
|
# FROM descendants namespaces
|
|
# ) groups;
|
|
#
|
|
# Using this approach allows us to further add criteria to the relation with
|
|
# Rails thinking it's selecting data the usual way.
|
|
def all_groups
|
|
return base unless Group.supports_nested_groups?
|
|
|
|
ancestors = base_and_ancestors_cte
|
|
descendants = base_and_descendants_cte
|
|
|
|
ancestors_table = ancestors.alias_to(groups_table)
|
|
descendants_table = descendants.alias_to(groups_table)
|
|
|
|
union = SQL::Union.new([model.unscoped.from(ancestors_table),
|
|
model.unscoped.from(descendants_table)])
|
|
|
|
model.
|
|
unscoped.
|
|
with.
|
|
recursive(ancestors.to_arel, descendants.to_arel).
|
|
from("(#{union.to_sql}) #{model.table_name}")
|
|
end
|
|
|
|
private
|
|
|
|
def base_and_ancestors_cte
|
|
cte = SQL::RecursiveCTE.new(:base_and_ancestors)
|
|
|
|
cte << base.except(:order)
|
|
|
|
# Recursively get all the ancestors of the base set.
|
|
cte << model.
|
|
from([groups_table, cte.table]).
|
|
where(groups_table[:id].eq(cte.table[:parent_id])).
|
|
except(:order)
|
|
|
|
cte
|
|
end
|
|
|
|
def base_and_descendants_cte
|
|
cte = SQL::RecursiveCTE.new(:base_and_descendants)
|
|
|
|
cte << base.except(:order)
|
|
|
|
# Recursively get all the descendants of the base set.
|
|
cte << model.
|
|
from([groups_table, cte.table]).
|
|
where(groups_table[:parent_id].eq(cte.table[:id])).
|
|
except(:order)
|
|
|
|
cte
|
|
end
|
|
|
|
def groups_table
|
|
model.arel_table
|
|
end
|
|
end
|
|
end
|