tg_cycle_component.gsql

CREATE DISTRIBUTED QUERY tg_cycle_component(STRING v_type,STRING e_type,BOOL print_results = TRUE, STRING result_attribute =  "", STRING file_path = "") SYNTAX v1{ 


    /*
    First Author: <First Author Name>
    First Commit Date:  <First Commit Date>

    Recent Author: <Recent Commit Author Name>
    Recent Commit Date: <Recent Commit Date>


    Repository:
        https://github.com/tigergraph/gsql-graph-algorithms/tree/master/algorithms/Path

    Maturity:
        production

    Description: 
        This algorithm is for undirected graph
        Find all vertex which are in a cycle

    Publications:
        <link>

    TigerGraph Documentation:
        <link>

    Parameters:
        v_type:
            vertex types to traverse
        e_type:
            edge types to traverse
        print_results:
            If True, weather print the result
        result_attribute:
            attribute to write result to
        file_path:
            file to write CSV output to
    */

  OrAccum @or_nocycle;
  SumAccum<INT> @sum_outdegree;
  SumAccum<INT> @@sum_stop=1;
  FILE f (file_path);
  Start = {v_type};
  WHILE @@sum_stop!=0 DO
        @@sum_stop=0;
        Start = SELECT s 
                FROM Start:s-(e_type)-v_type:t 
                WHERE t.@or_nocycle==FALSE and s!=t
                ACCUM s.@sum_outdegree+=1
                POST-ACCUM IF s.@sum_outdegree==1 THEN @@sum_stop+=1,s.@or_nocycle+=TRUE END,
                           s.@sum_outdegree=0
                HAVING s.@or_nocycle==FALSE;
        
  END;
  # Output
  IF file_path != "" THEN
      f.println("Vertex_ID_In_cycle");
  END;

  V = SELECT s 
      FROM Start:s
      POST-ACCUM 
          IF result_attribute != "" THEN 
              s.setAttr(result_attribute, TRUE) 
          END,
   
          IF file_path != "" THEN 
              f.println(s) 
          END;
   
  IF print_results THEN
      PRINT Start;
  END;
  
  PRINT "tg_cycle_component works!"; 
}