/** Adds recent message in history. */
  private void saveRecentMessageToHistory(ComparableEvtObj msc) {
    synchronized (historyID) {
      // and create it
      try {
        History history = getHistory();
        HistoryWriter writer = history.getWriter();

        SimpleDateFormat sdf = new SimpleDateFormat(HistoryService.DATE_FORMAT);

        writer.addRecord(
            new String[] {
              msc.getProtocolProviderService().getAccountID().getAccountUniqueID(),
              msc.getContactAddress(),
              sdf.format(msc.getTimestamp()),
              RECENT_MSGS_VER
            },
            NUMBER_OF_MSGS_IN_HISTORY);
      } catch (IOException ex) {
        logger.error("cannot create recent_messages history", ex);
        return;
      }
    }
  }
  /** Updates recent message in history. */
  private void updateRecentMessageToHistory(final ComparableEvtObj msg) {
    synchronized (historyID) {
      // and create it
      try {
        History history = getHistory();

        HistoryWriter writer = history.getWriter();

        writer.updateRecord(
            new HistoryWriter.HistoryRecordUpdater() {
              HistoryRecord hr;

              @Override
              public void setHistoryRecord(HistoryRecord historyRecord) {
                this.hr = historyRecord;
              }

              @Override
              public boolean isMatching() {
                boolean providerFound = false;
                boolean contactFound = false;
                for (int i = 0; i < hr.getPropertyNames().length; i++) {
                  String propName = hr.getPropertyNames()[i];

                  if (propName.equals(STRUCTURE_NAMES[0])) {
                    if (msg.getProtocolProviderService()
                        .getAccountID()
                        .getAccountUniqueID()
                        .equals(hr.getPropertyValues()[i])) {
                      providerFound = true;
                    }
                  } else if (propName.equals(STRUCTURE_NAMES[1])) {
                    if (msg.getContactAddress().equals(hr.getPropertyValues()[i])) {
                      contactFound = true;
                    }
                  }
                }

                return contactFound && providerFound;
              }

              @Override
              public Map<String, String> getUpdateChanges() {
                HashMap<String, String> map = new HashMap<String, String>();
                SimpleDateFormat sdf = new SimpleDateFormat(HistoryService.DATE_FORMAT);

                for (int i = 0; i < hr.getPropertyNames().length; i++) {
                  String propName = hr.getPropertyNames()[i];

                  if (propName.equals(STRUCTURE_NAMES[0])) {
                    map.put(
                        propName,
                        msg.getProtocolProviderService().getAccountID().getAccountUniqueID());
                  } else if (propName.equals(STRUCTURE_NAMES[1])) {
                    map.put(propName, msg.getContactAddress());
                  } else if (propName.equals(STRUCTURE_NAMES[2])) {
                    map.put(propName, sdf.format(msg.getTimestamp()));
                  } else if (propName.equals(STRUCTURE_NAMES[3]))
                    map.put(propName, RECENT_MSGS_VER);
                }

                return map;
              }
            });
      } catch (IOException ex) {
        logger.error("cannot create recent_messages history", ex);
        return;
      }
    }
  }