| /* |
| * Copyright 2015-present Open Networking Foundation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.onosproject.store.service; |
| |
| import java.util.Collection; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.function.BiFunction; |
| |
| /** |
| * A distributed, eventually consistent map. |
| * <p> |
| * This map does not offer read after writes consistency. Operations are |
| * serialized via the timestamps issued by the clock service. If two updates |
| * are in conflict, the update with the more recent timestamp will endure. |
| * </p><p> |
| * The interface is mostly similar to {@link java.util.Map} with some minor |
| * semantic changes and the addition of a listener framework (because the map |
| * can be mutated by clients on other instances, not only through the local Java |
| * API). |
| * </p><p> |
| * Clients are expected to register an |
| * {@link EventuallyConsistentMapListener} if they |
| * are interested in receiving notifications of update to the map. |
| * </p><p> |
| * Null values are not allowed in this map. |
| * </p> |
| */ |
| public interface EventuallyConsistentMap<K, V> extends DistributedPrimitive { |
| |
| @Override |
| default DistributedPrimitive.Type primitiveType() { |
| return DistributedPrimitive.Type.EVENTUALLY_CONSISTENT_MAP; |
| } |
| |
| /** |
| * Returns the number of key-value mappings in this map. |
| * |
| * @return number of key-value mappings |
| */ |
| int size(); |
| |
| /** |
| * Returns true if this map is empty. |
| * |
| * @return true if this map is empty, otherwise false |
| */ |
| boolean isEmpty(); |
| |
| /** |
| * Returns true if the map contains a mapping for the specified key. |
| * |
| * @param key the key to check if this map contains |
| * @return true if this map has a mapping for the key, otherwise false |
| */ |
| boolean containsKey(K key); |
| |
| /** |
| * Returns true if the map contains a mapping from any key to the specified |
| * value. |
| * |
| * @param value the value to check if this map has a mapping for |
| * @return true if this map has a mapping to this value, otherwise false |
| */ |
| boolean containsValue(V value); |
| |
| /** |
| * Returns the value mapped to the specified key. |
| * |
| * @param key the key to look up in this map |
| * @return the value mapped to the key, or null if no mapping is found |
| */ |
| V get(K key); |
| |
| /** |
| * Associates the specified value to the specified key in this map. |
| * <p> |
| * Note: this differs from the specification of {@link java.util.Map} |
| * because it does not return the previous value associated with the key. |
| * Clients are expected to register an |
| * {@link EventuallyConsistentMapListener} if |
| * they are interested in receiving notification of updates to the map. |
| * </p><p> |
| * Null values are not allowed in the map. |
| * </p> |
| * |
| * @param key the key to add a mapping for in this map |
| * @param value the value to associate with the key in this map |
| */ |
| void put(K key, V value); |
| |
| /** |
| * Removes the mapping associated with the specified key from the map. |
| * <p> |
| * Clients are expected to register an {@link EventuallyConsistentMapListener} if |
| * they are interested in receiving notification of updates to the map. |
| * </p> |
| * |
| * @param key the key to remove the mapping for |
| * @return previous value associated with key, or null if there was no mapping for key. |
| */ |
| V remove(K key); |
| |
| /** |
| * Removes the given key-value mapping from the map, if it exists. |
| * <p> |
| * This actually means remove any values up to and including the timestamp |
| * given by the map's timestampProvider. |
| * Any mappings that produce an earlier timestamp than this given key-value |
| * pair will be removed, and any mappings that produce a later timestamp |
| * will supersede this remove. |
| * </p><p> |
| * Note: this differs from the specification of {@link java.util.Map} |
| * because it does not return a boolean indication whether a value was removed. |
| * Clients are expected to register an |
| * {@link EventuallyConsistentMapListener} if |
| * they are interested in receiving notification of updates to the map. |
| * </p> |
| * |
| * @param key the key to remove the mapping for |
| * @param value the value mapped to the key |
| */ |
| void remove(K key, V value); |
| |
| /** |
| * Attempts to compute a mapping for the specified key and its current mapped |
| * value (or null if there is no current mapping). |
| * <p> |
| * If the function returns null, the mapping is removed (or remains absent if initially absent). |
| * @param key map key |
| * @param recomputeFunction function to recompute a new value |
| * @return new value |
| */ |
| V compute(K key, BiFunction<K, V, V> recomputeFunction); |
| |
| /** |
| * Adds mappings for all key-value pairs in the specified map to this map. |
| * <p> |
| * This will be more efficient in communication than calling individual put |
| * operations. |
| * </p> |
| * |
| * @param m a map of values to add to this map |
| */ |
| void putAll(Map<? extends K, ? extends V> m); |
| |
| /** |
| * Removes all mappings from this map. |
| */ |
| void clear(); |
| |
| /** |
| * Returns a set of the keys in this map. Changes to the set are not |
| * reflected back to the map. |
| * |
| * @return set of keys in the map |
| */ |
| Set<K> keySet(); |
| |
| /** |
| * Returns a collections of values in this map. Changes to the collection |
| * are not reflected back to the map. |
| * |
| * @return collection of values in the map |
| */ |
| Collection<V> values(); |
| |
| /** |
| * Returns a set of mappings contained in this map. Changes to the set are |
| * not reflected back to the map. |
| * |
| * @return set of key-value mappings in this map |
| */ |
| Set<Map.Entry<K, V>> entrySet(); |
| |
| /** |
| * Adds the specified listener to the map which will be notified whenever |
| * the mappings in the map are changed. |
| * |
| * @param listener listener to register for events |
| */ |
| void addListener(EventuallyConsistentMapListener<K, V> listener); |
| |
| /** |
| * Removes the specified listener from the map such that it will no longer |
| * receive change notifications. |
| * |
| * @param listener listener to deregister for events |
| */ |
| void removeListener(EventuallyConsistentMapListener<K, V> listener); |
| } |