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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.net.cache;
import com.tangosol.util.InvocableMap;
import com.tangosol.util.ObservableMap;
import java.util.Collection;
import java.util.Map;
import java.util.Objects;
import java.util.function.BiConsumer;
/**
* A CacheMap is a Map that supports caching. This interface will be
* eventually replaced by the javax.cache.Cache interface.
*
* @param the type of the Map entry keys
* @param the type of the Map entry values
*
* @author gg 2004.01.05
*
* @since Coherence 2.3
*/
public interface CacheMap
extends ObservableMap
{
/**
* Get all the specified keys, if they are in the cache. For each key
* that is in the cache, that key and its corresponding value will be
* placed in the map that is returned by this method. The absence of
* a key in the returned map indicates that it was not in the cache,
* which may imply (for caches that can load behind the scenes) that
* the requested data could not be loaded.
*
* The result of this method is defined to be semantically the same as
* the following implementation, without regards to threading issues:
*
*
* Map map = new AnyMap(); // could be a HashMap (but does not have to)
* for (Iterator iter = colKeys.iterator(); iter.hasNext(); )
* {
* Object oKey = iter.next();
* Object oVal = get(oKey);
* if (oVal != null || containsKey(oKey))
* {
* map.put(oKey, oVal);
* }
* }
* return map;
*
*
* @param colKeys a collection of keys that may be in the named cache
*
* @return a Map of keys to values for the specified keys passed in
* colKeys
*
* @since Coherence 2.5
*/
public Map getAll(Collection colKeys);
/**
* Associates the specified value with the specified key in this cache.
* If the cache previously contained a mapping for this key, the old
* value is replaced.
*
* Invoking this method is equivalent to the following call:
*
* put(oKey, oValue, EXPIRY_DEFAULT);
*
*
* @param key key with which the specified value is to be associated
* @param value value to be associated with the specified key
*
* @return previous value associated with specified key, or null
* if there was no mapping for key. A null return can
* also indicate that the map previously associated null
* with the specified key, if the implementation supports
* null values
*/
public V put(K key, V value);
/**
* Associates the specified value with the specified key in this cache.
* If the cache previously contained a mapping for this key, the old
* value is replaced.
* This variation of the {@link #put(Object oKey, Object oValue)}
* method allows the caller to specify an expiry (or "time to live")
* for the cache entry.
*
* @param key key with which the specified value is to be associated
* @param value value to be associated with the specified key
* @param cMillis the number of milliseconds until the cache entry will
* expire, also referred to as the entry's "time to live";
* pass {@link #EXPIRY_DEFAULT} to use the cache's default
* time-to-live setting; pass {@link #EXPIRY_NEVER} to
* indicate that the cache entry should never expire; this
* milliseconds value is not a date/time value, such
* as is returned from System.currentTimeMillis()
*
* @return previous value associated with specified key, or null
* if there was no mapping for key. A null return can
* also indicate that the map previously associated null
* with the specified key, if the implementation supports
* null values
*
* @throws UnsupportedOperationException if the requested expiry is a
* positive value and the implementation does not support expiry
* of cache entries
*/
public V put(K key, V value, long cMillis);
/**
* Perform the given action for each entry selected by the specified key set
* until all entries have been processed or the action throws an exception.
*
* Exceptions thrown by the action are relayed to the caller.
*
* The implementation processes each entry on the client and should only be
* used for read-only client-side operations (such as adding map entries to
* a UI widget, for example).
*
* Any entry mutation caused by the specified action will not be propagated
* to the server when this method is called on a distributed map, so it
* should be avoided. The mutating operations on a subset of entries
* should be implemented using one of {@link InvocableMap#invokeAll},
* {@link #replaceAll}, {@link #compute}, or {@link #merge} methods instead.
*
* @param collKeys the keys to process; these keys are not required to
* exist within the Map
* @param action the action to be performed for each entry
*
* @since 12.2.1
*/
public default void forEach(Collection collKeys, BiConsumer action)
{
Objects.requireNonNull(action);
getAll(collKeys).entrySet().forEach(entry -> action.accept(entry.getKey(), entry.getValue()));
}
/**
* A special time-to-live value that can be passed to the extended
* {@link #put(Object, Object, long) put} method to indicate that the
* cache's default expiry should be used.
*/
public static final long EXPIRY_DEFAULT = 0L;
/**
* A special time-to-live value that can be passed to the extended
* {@link #put(Object, Object, long) put} method to indicate that the
* cache entry should never expire.
*/
public static final long EXPIRY_NEVER = -1L;
}