/** Perform cleanup of the trash directory. */
  private void delete() {
    IgfsFileInfo info = null;

    try {
      info = meta.info(TRASH_ID);
    } catch (ClusterTopologyServerNotFoundException e) {
      LT.warn(log, e, "Server nodes not found.");
    } catch (IgniteCheckedException e) {
      U.error(log, "Cannot obtain trash directory info.", e);
    }

    if (info != null) {
      for (Map.Entry<String, IgfsListingEntry> entry : info.listing().entrySet()) {
        IgniteUuid fileId = entry.getValue().fileId();

        if (log.isDebugEnabled())
          log.debug(
              "Deleting IGFS trash entry [name=" + entry.getKey() + ", fileId=" + fileId + ']');

        try {
          if (!cancelled) {
            if (delete(entry.getKey(), fileId)) {
              if (log.isDebugEnabled())
                log.debug(
                    "Sending delete confirmation message [name="
                        + entry.getKey()
                        + ", fileId="
                        + fileId
                        + ']');

              sendDeleteMessage(new IgfsDeleteMessage(fileId));
            }
          } else break;
        } catch (IgniteInterruptedCheckedException ignored) {
          // Ignore this exception while stopping.
        } catch (IgniteCheckedException e) {
          U.error(log, "Failed to delete entry from the trash directory: " + entry.getKey(), e);

          sendDeleteMessage(new IgfsDeleteMessage(fileId, e));
        }
      }
    }
  }
  /**
   * Send delete message to all meta cache nodes in the grid.
   *
   * @param msg Message to send.
   */
  private void sendDeleteMessage(IgfsDeleteMessage msg) {
    assert msg != null;

    Collection<ClusterNode> nodes = meta.metaCacheNodes();

    for (ClusterNode node : nodes) {
      try {
        igfsCtx.send(node, topic, msg, GridIoPolicy.SYSTEM_POOL);
      } catch (IgniteCheckedException e) {
        U.warn(
            log,
            "Failed to send IGFS delete message to node [nodeId="
                + node.id()
                + ", msg="
                + msg
                + ", err="
                + e.getMessage()
                + ']');
      }
    }
  }