org.gridgain.grid

Interface GridNodeLocalMap<K,V>

All Superinterfaces:

ConcurrentMap<K,V>, GridMetadataAware, Map<K,V>, Serializable

All Known Implementing Classes:

GridNodeLocalMapImpl

public interface GridNodeLocalMap<K,V>
extends ConcurrentMap<K,V>, GridMetadataAware

Defines interface for node-local storage.

GridNodeLocalMap is similar to ThreadLocal in a way that its values are not distributed and kept only on local node (similar like ThreadLocal values are attached to the current thread only). Node-local values are used primarily by jobs executed from the remote nodes to keep intermediate state on the local node between executions.

GridNodeLocalMap essentially is a ConcurrentMap with a few additional methods, so it is fairly trivial to use.

You can get an instance of GridNodeLocalMap by calling Grid.nodeLocalMap() method.

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Method Summary

Methods

Modifier and Type	Method and Description
V	addIfAbsent(K key, Callable<V> dflt) Gets the value with given key.
V	addIfAbsent(K key, V val) Unlike its sibling method ConcurrentMap.putIfAbsent(Object, Object) this method returns current mapping from the map.

Methods inherited from interface java.util.concurrent.ConcurrentMap

putIfAbsent, remove, replace, replace

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from interface org.gridgain.grid.GridMetadataAware

addMeta, addMetaIfAbsent, addMetaIfAbsent, allMeta, copyMeta, copyMeta, hasMeta, hasMeta, meta, putMetaIfAbsent, putMetaIfAbsent, removeMeta, removeMeta, replaceMeta

Method Detail

addIfAbsent

V addIfAbsent(K key,
            @Nullable
            Callable<V> dflt)

Gets the value with given key. If that value does not exist, calls given closure to get the default value, puts it into the map and returns it. If closure is null return null.

Parameters:

key - Key to get the value for.

dflt - Default value producing closure.

Returns:

Value for the key or the value produced by the closure if key does not exist in the map. Return null if key is not found and closure is null.

addIfAbsent

V addIfAbsent(K key,
            V val)

Unlike its sibling method ConcurrentMap.putIfAbsent(Object, Object) this method returns current mapping from the map.

Parameters:

key - Key.

val - Value to put if one does not exist.

Returns:

Current mapping for a given key.