/**
* Puts a DHTObject into the index database. Internally, the expiration timeout of the data item
* is set to be {@link KademliaConfig#DATA_EXPIRATION_TIME} from the current simulation time
* ("now").
*
* <p>Adding an item does <i>not</i> overwrite an existing value if it is stored under the same
* key. It is furthermore assumed that this method is called each time a data item is republished,
* even if the initiator of that republish is the local node.
*
* @param key the KademliaOverlayKey belonging to the DHTObject.
* @param newValue the DHTObject that represents the data item to be inserted.
*/
public final void put(final KademliaOverlayKey key, final DHTObject newValue) {
KademliaIndexEntry indexEntry;
indexEntry = index.get(key);
if (indexEntry == null) {
indexEntry = new KademliaIndexEntry(newValue, config);
index.put(key, indexEntry);
}
// set last republish time
indexEntry.updateLastRepublish();
}
/**
* Looks up the DHTObject associated with <code>key</code> in the local database.
*
* @param key the KademliaOverlayKey of the data item to be looked up.
* @return the DHTObject associated with <code>key</code>. If no such object exists (or it has
* expired), <code>null</code> is returned.
*/
public final DHTObject get(final KademliaOverlayKey key) {
final KademliaIndexEntry indexEntry = index.get(key);
if (indexEntry == null) { // no entry known
return null;
} else if (indexEntry.hasExpired()) { // old entry expired
index.remove(key);
return null;
}
return indexEntry.getValue();
}
