Method call

src/core/SaltScanner.java:535–726

Iterate through each row of the scanner results, parses out data points (and optional meta data). @return null if no rows were found, otherwise the SortedMap with spans

(final ArrayList<ArrayList<KeyValue>> rows)

    * @return null if no rows were found, otherwise the SortedMap with spans
    */
    @Override
    public Object call(final ArrayList<ArrayList<KeyValue>> rows) 
            throws Exception {
      try {
        fetch_time += DateTime.nanoTime() - fetch_start;
        if (rows == null) {
          close(true);
          return null;
        } else if (exception != null) {
          close(false);
          // don't need to handleException here as it's already taken care of
          // due to the fact that exception was set.
          if (LOG.isDebugEnabled()) {
            LOG.debug("Closing scanner as there was an exception: " + scanner);
          }
          return null;
        }

        // used for UID resolution if a filter is involved
        final List<Deferred<Object>> lookups = 
            filters != null && !filters.isEmpty() ? 
                new ArrayList<Deferred<Object>>(rows.size()) : null;
        
        // validation checking before processing the next set of results. It's 
        // kinda funky but we want to allow queries to sneak through that were
        // just a *tad* over the limits so that's why we don't check at the 
        // end of a scan call.
        if (max_data_points > 0 && num_data_points.get() >= max_data_points) {
          max_data_points_flag.getAndSet(true);
          try {
            close(false);
            handleException(
                new QueryException(HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE,
                "Sorry, you have attempted to fetch more than our limit of " 
                    + max_data_points + " data points. Please try filtering "
                    + "using more tags or decrease your time range."));
            return false;
          } catch (Exception e) {
            LOG.error("Sorry, Scanner is closed: " + scanner, e);
            return false;
          }
        }
        
        if (max_bytes > 0 && bytes_fetched.get() > max_bytes) {
          max_data_points_flag.getAndSet(true);
          try {
            close(false);
            handleException(
                new QueryException(HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE,
                "Sorry, you have attempted to fetch more than our maximum "
                    + "amount of " + (max_bytes / 1024 / 1024) + "MB from storage. " 
                    + "Please try filtering using more tags or decrease your time range."));
            return false;
          } catch (Exception e) {
            LOG.error("Sorry, Scanner is closed: " + scanner, e);
            return false;
          }
        }