/**
   * Configure the history length for a specific entry. If the length is 0 disable history for this
   * key
   *
   * @param pKey history key
   * @param pMaxEntries number of maximal entries. If larger than globalMaxEntries, then
   *     globalMaxEntries is used instead.
   */
  public synchronized void configure(HistoryKey pKey, int pMaxEntries) {
    int maxEntries = pMaxEntries > globalMaxEntries ? globalMaxEntries : pMaxEntries;

    // Remove entries if set to 0
    if (pMaxEntries == 0) {
      removeEntries(pKey);
      return;
    }
    if (pKey.isMBeanPattern()) {
      patterns.put(pKey, maxEntries);
      // Trim all already stored keys
      for (HistoryKey key : historyStore.keySet()) {
        if (pKey.matches(key)) {
          HistoryEntry entry = historyStore.get(key);
          entry.setMaxEntries(maxEntries);
          entry.trim();
        }
      }
    } else {
      HistoryEntry entry = historyStore.get(pKey);
      if (entry != null) {
        entry.setMaxEntries(maxEntries);
        entry.trim();
      } else {
        entry = new HistoryEntry(maxEntries);
        historyStore.put(pKey, entry);
      }
    }
  }
 private HistoryEntry getEntry(HistoryKey pKey, Object pValue, long pTimestamp) {
   HistoryEntry entry = historyStore.get(pKey);
   if (entry != null) {
     return entry;
   }
   // Now try all known patterns and add lazily the key
   for (HistoryKey key : patterns.keySet()) {
     if (key.matches(pKey)) {
       entry = new HistoryEntry(patterns.get(key));
       entry.add(pValue, pTimestamp);
       historyStore.put(pKey, entry);
       return entry;
     }
   }
   return null;
 }
 // Remove entries
 private void removeEntries(HistoryKey pKey) {
   if (pKey.isMBeanPattern()) {
     patterns.remove(pKey);
     List<HistoryKey> toRemove = new ArrayList<HistoryKey>();
     for (HistoryKey key : historyStore.keySet()) {
       if (pKey.matches(key)) {
         toRemove.add(key);
       }
     }
     // Avoid concurrent modification exceptions
     for (HistoryKey key : toRemove) {
       historyStore.remove(key);
     }
   } else {
     HistoryEntry entry = historyStore.get(pKey);
     if (entry != null) {
       historyStore.remove(pKey);
     }
   }
 }