| /* |
| * Copyright 2015 Open Networking Laboratory |
| * |
| * 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; |
| |
| /** |
| * Transactional Map data structure. |
| * <p> |
| * A TransactionalMap is created by invoking {@link TransactionContext#getTransactionalMap getTransactionalMap} |
| * method. All operations performed on this map within a transaction boundary are invisible externally |
| * until the point when the transaction commits. A commit usually succeeds in the absence of conflicts. |
| * |
| * @param <K> type of key. |
| * @param <V> type of value. |
| */ |
| public interface TransactionalMap<K, V> { |
| |
| /** |
| * Returns the value to which the specified key is mapped, or null if this |
| * map contains no mapping for the key. |
| * |
| * @param key the key whose associated value is to be returned |
| * @return the value to which the specified key is mapped, or null if |
| * this map contains no mapping for the key |
| */ |
| V get(K key); |
| |
| /** |
| * Associates the specified value with the specified key in this map (optional operation). |
| * If the map previously contained a mapping for the key, the old value is replaced by the |
| * specified value. |
| * |
| * @param key key with which the specified value is to be associated |
| * @param value value to be associated with the specified key |
| * @return the previous value associated with key, or null if there was |
| * no mapping for key. |
| */ |
| V put(K key, V value); |
| |
| /** |
| * Removes the mapping for a key from this map if it is present (optional operation). |
| * |
| * @param key key whose value is to be removed from the map |
| * @return the value to which this map previously associated the key, |
| * or null if the map contained no mapping for the key. |
| */ |
| V remove(K key); |
| |
| /** |
| * If the specified key is not already associated with a value |
| * associates it with the given value and returns null, else returns the current value. |
| * |
| * @param key key with which the specified value is to be associated |
| * @param value value to be associated with the specified key |
| * @return the previous value associated with the specified key or null |
| * if key does not already mapped to a value. |
| */ |
| V putIfAbsent(K key, V value); |
| |
| /** |
| * Removes the entry for the specified key only if it is currently |
| * mapped to the specified value. |
| * |
| * @param key key with which the specified value is associated |
| * @param value value expected to be associated with the specified key |
| * @return true if the value was removed |
| */ |
| boolean remove(K key, V value); |
| |
| /** |
| * Replaces the entry for the specified key only if currently mapped |
| * to the specified value. |
| * |
| * @param key key with which the specified value is associated |
| * @param oldValue value expected to be associated with the specified key |
| * @param newValue value to be associated with the specified key |
| * @return true if the value was replaced |
| */ |
| boolean replace(K key, V oldValue, V newValue); |
| } |