}
}

/*
** Load the record ID rid and up to N-1 closest ancestors into
** the "ok" table.
*/
void compute_ancestors(int rid, int N, int directOnly){
  Bag seen;
  PQueue queue;
  Stmt ins;
  Stmt q;
  bag_init(&seen);
  pqueue_init(&queue);
  bag_insert(&seen, rid);
  pqueue_insert(&queue, rid, 0.0, 0);
  db_prepare(&ins, "INSERT OR IGNORE INTO ok VALUES(:rid)");
  db_prepare(&q,
    "SELECT a.pid, b.mtime FROM plink a LEFT JOIN plink b ON b.cid=a.pid"
    " WHERE a.cid=:rid %s",
    directOnly ? " AND a.isprim" : ""
  );
  while( (N--)>0 && (rid = pqueue_extract(&queue, 0))!=0 ){
    db_bind_int(&ins, ":rid", rid);
    db_step(&ins);
    db_reset(&ins);
    db_bind_int(&q, ":rid", rid);
    while( db_step(&q)==SQLITE_ROW ){

** direct ancestor as the largest generation number.
*/
void compute_direct_ancestors(int rid, int N){
  Stmt ins;
  Stmt q;
  int gen = 0;
  db_multi_exec(
    "CREATE TEMP TABLE IF NOT EXISTS ancestor(rid INTEGER,"
                                            " generation INTEGER PRIMARY KEY);"
    "DELETE FROM ancestor;"
    "INSERT INTO ancestor VALUES(%d, 0);", rid
  );
  db_prepare(&ins, "INSERT INTO ancestor VALUES(:rid, :gen)");
  db_prepare(&q, 
    "SELECT pid FROM plink"
    " WHERE cid=:rid AND isprim"
  );

    db_bind_int(&ins, ":gen", gen);
    db_step(&ins);
    db_reset(&ins);
  }
  db_finalize(&ins);
  db_finalize(&q);
}

/*
** Compute the "mtime" of the file given whose blob.rid is "fid" that
** is part of check-in "vid".  The mtime will be the mtime on vid or
** some ancestor of vid where fid first appears.
*/
int mtime_of_manifest_file(
  int vid,       /* The check-in that contains fid */
  int fid,       /* The id of the file whose check-in time is sought */
  i64 *pMTime    /* Write result here */
){
  static int prevVid = -1;
  static Stmt q;

  if( prevVid!=vid ){
    prevVid = vid;
    db_multi_exec("DROP TABLE IF EXISTS temp.ok;"
                  "CREATE TEMP TABLE ok(x INTEGER PRIMARY KEY);");
    compute_ancestors(vid, 100000000, 1);
  }
  db_static_prepare(&q,
    "SELECT (max(event.mtime)-2440587.5)*86400 FROM mlink, event"
    " WHERE mlink.mid=event.objid"
    "   AND +mlink.mid IN ok"
    "   AND mlink.fid=:fid");
  db_bind_int(&q, ":fid", fid);
  if( db_step(&q)!=SQLITE_ROW ){
    db_reset(&q);
    return 1;
  }
  *pMTime = db_column_int64(&q, 0);
  db_reset(&q);
  return 0;
}

/*
** Load the record ID rid and up to N-1 closest descendants into
** the "ok" table.
*/
void compute_descendants(int rid, int N){
  Bag seen;