+ col_uuids << child[:output_uuid] if child[:output_uuid]
+ col_pdhs += ProvenanceHelper::cr_input_pdhs(child)
+ end
+ end
+
+ output_cols = {} # Indexed by UUID
+ input_cols = {} # Indexed by PDH
+ output_pdhs = []
+
+ # Batch requests to get all related collections
+ # First fetch output collections by UUID.
+ Collection.filter([['uuid', 'in', col_uuids.uniq]]).each do |c|
+ output_cols[c[:uuid]] = c
+ output_pdhs << c[:portable_data_hash]
+ end
+ # Then, get only input collections by PDH. There could be more than one collection
+ # per PDH: the number of collections is used on the collection node label.
+ Collection.filter(
+ [['portable_data_hash', 'in', col_pdhs - output_pdhs]]).each do |c|
+ if input_cols[c[:portable_data_hash]]
+ input_cols[c[:portable_data_hash]] << c
+ else
+ input_cols[c[:portable_data_hash]] = [c]