Package org.jivesoftware.util.cache

Class ReverseLookupUpdatingCacheEntryListener<K,V>

java.lang.Object
org.jivesoftware.util.cache.ReverseLookupUpdatingCacheEntryListener<K,V>
All Implemented Interfaces:
ClusteredCacheEntryListener<K,V>
public class ReverseLookupUpdatingCacheEntryListener<K,V> extends Object implements ClusteredCacheEntryListener<K,V>
Cache entry listener implementation that maintains a reverse lookup map for the cache that is being observed, which is used to identify what cluster node is the logical owner of a particular cache entry. This information is typically useful in scenarios where a cluster node drops out of the cluster requiring the remaining nodes to have to inform their connected entities of what resources have become unavailable. This implementation can be used in scenarios where exactly one cluster node 'owns' data (eg: client connection), as well as in scenarios where more than one cluster node 'owns' data (eg: component sessions). Instances can be configured to expect a unique owner (through a boolean argument in the constructor). When operating in that mode, an entry addition or update will cause entries for other nodes to be removed. This can be particularly helpful when events arrive 'out of order' (which could lead to data inconsistencies). This implementation assumes that the cluster node on which the cache entry change originates is an owner of the corresponding entry.

  • Constructor Details

    • ReverseLookupUpdatingCacheEntryListener

      public ReverseLookupUpdatingCacheEntryListener(@Nonnull ConcurrentMap<NodeID,Set<K>> reverseCacheRepresentation)

    • ReverseLookupUpdatingCacheEntryListener

      public ReverseLookupUpdatingCacheEntryListener(@Nonnull ConcurrentMap<NodeID,Set<K>> reverseCacheRepresentation, boolean uniqueOwnerExpected)

  • Method Details

    • entryAdded

      public void entryAdded(@Nonnull K key, @Nullable V value, @Nonnull NodeID nodeID)
      Description copied from interface: ClusteredCacheEntryListener
      An entry was added to the cache.
      Specified by:
      entryAdded in interface ClusteredCacheEntryListener<K,V>
      Parameters:
      key - The key of the entry that was added.
      value - The (optional) value of the entry that was added.
      nodeID - identifier of the node on which the cache modification occurred.

    • entryRemoved

      public void entryRemoved(@Nonnull K key, @Nullable V oldValue, @Nonnull NodeID nodeID)
      Description copied from interface: ClusteredCacheEntryListener
      An entry was removed from the cache.
      Specified by:
      entryRemoved in interface ClusteredCacheEntryListener<K,V>
      Parameters:
      key - The key of the entry that was removed.
      oldValue - The (optional) value of the entry that was removed.
      nodeID - identifier of the node on which the cache modification occurred.

    • entryUpdated

      public void entryUpdated(@Nonnull K key, @Nullable V oldValue, @Nullable V newValue, @Nonnull NodeID nodeID)
      Description copied from interface: ClusteredCacheEntryListener
      An entry was updated in the cache.
      Specified by:
      entryUpdated in interface ClusteredCacheEntryListener<K,V>
      Parameters:
      key - The key of the entry that was changed.
      oldValue - The (optional) value of the entry prior to the update.
      newValue - The (optional) value of the entry after to the update.
      nodeID - identifier of the node on which the cache modification occurred.

    • entryEvicted

      public void entryEvicted(@Nonnull K key, @Nullable V oldValue, @Nonnull NodeID nodeID)
      Description copied from interface: ClusteredCacheEntryListener
      An entry was evicted from the cache.
      Specified by:
      entryEvicted in interface ClusteredCacheEntryListener<K,V>
      Parameters:
      key - The key of the entry that was evicted.
      oldValue - The (optional) value of the entry that was removed.
      nodeID - identifier of the node on which the cache modification occurred.

    • mapCleared

      public void mapCleared(@Nonnull NodeID nodeID)
      Description copied from interface: ClusteredCacheEntryListener
      The cache was cleared.
      Specified by:
      mapCleared in interface ClusteredCacheEntryListener<K,V>
      Parameters:
      nodeID - identifier of the node on which the cache modification occurred.

    • mapEvicted

      public void mapEvicted(@Nonnull NodeID nodeID)
      Description copied from interface: ClusteredCacheEntryListener
      The cache was evicted.
      Specified by:
      mapEvicted in interface ClusteredCacheEntryListener<K,V>
      Parameters:
      nodeID - identifier of the node on which the cache modification occurred.