gitlab-org--gitlab-foss/app/models/clusters/clusters_hierarchy.rb
Thong Kuah 3bc76511a0 Create CTE query for clusters hierarchy
- This enables us to use a scope to query all clusters in group
hierarchy order in one query, and also enables us to union to instance
clusters later.

- Handle case where clusters not present at level. In which case the
query should go ahead and return the next level's clusters.

- Swap with new CTE query behind Feature flag. This FF is default
disabled.
2019-07-08 06:03:09 +00:00

104 lines
2.7 KiB
Ruby

# frozen_string_literal: true
module Clusters
class ClustersHierarchy
DEPTH_COLUMN = :depth
def initialize(clusterable)
@clusterable = clusterable
end
# Returns clusters in order from deepest to highest group
def base_and_ancestors
cte = recursive_cte
cte_alias = cte.table.alias(model.table_name)
model
.unscoped
.where('clusters.id IS NOT NULL')
.with
.recursive(cte.to_arel)
.from(cte_alias)
.order(DEPTH_COLUMN => :asc)
end
private
attr_reader :clusterable
def recursive_cte
cte = Gitlab::SQL::RecursiveCTE.new(:clusters_cte)
base_query = case clusterable
when ::Group
group_clusters_base_query
when ::Project
project_clusters_base_query
else
raise ArgumentError, "unknown type for #{clusterable}"
end
cte << base_query
cte << parent_query(cte)
cte
end
def group_clusters_base_query
group_parent_id_alias = alias_as_column(groups[:parent_id], 'group_parent_id')
join_sources = ::Group.left_joins(:clusters).join_sources
model
.unscoped
.select([clusters_star, group_parent_id_alias, "1 AS #{DEPTH_COLUMN}"])
.where(groups[:id].eq(clusterable.id))
.from(groups)
.joins(join_sources)
end
def project_clusters_base_query
projects = ::Project.arel_table
project_parent_id_alias = alias_as_column(projects[:namespace_id], 'group_parent_id')
join_sources = ::Project.left_joins(:clusters).join_sources
model
.unscoped
.select([clusters_star, project_parent_id_alias, "1 AS #{DEPTH_COLUMN}"])
.where(projects[:id].eq(clusterable.id))
.from(projects)
.joins(join_sources)
end
def parent_query(cte)
group_parent_id_alias = alias_as_column(groups[:parent_id], 'group_parent_id')
model
.unscoped
.select([clusters_star, group_parent_id_alias, cte.table[DEPTH_COLUMN] + 1])
.from([cte.table, groups])
.joins('LEFT OUTER JOIN cluster_groups ON cluster_groups.group_id = namespaces.id')
.joins('LEFT OUTER JOIN clusters ON cluster_groups.cluster_id = clusters.id')
.where(groups[:id].eq(cte.table[:group_parent_id]))
end
def model
Clusters::Cluster
end
def clusters
@clusters ||= model.arel_table
end
def groups
@groups ||= ::Group.arel_table
end
def clusters_star
@clusters_star ||= clusters[Arel.star]
end
def alias_as_column(value, alias_to)
Arel::Nodes::As.new(value, Arel::Nodes::SqlLiteral.new(alias_to))
end
end
end