| package org.eclipse.aether; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| /** |
| * A container for data that is specific to a repository system session. Both components within the repository system |
| * and clients of the system may use this storage to associate arbitrary data with a session. |
| * <p> |
| * Unlike a cache, this session data is not subject to purging. For this same reason, session data should also not be |
| * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion. |
| * <p> |
| * <strong>Note:</strong> Actual implementations must be thread-safe. |
| * |
| * @see RepositorySystemSession#getData() |
| * @noimplement This interface is not intended to be implemented by clients. |
| * @noextend This interface is not intended to be extended by clients. |
| */ |
| public interface SessionData |
| { |
| |
| /** |
| * Associates the specified session data with the given key. |
| * |
| * @param key The key under which to store the session data, must not be {@code null}. |
| * @param value The data to associate with the key, may be {@code null} to remove the mapping. |
| */ |
| void set( Object key, Object value ); |
| |
| /** |
| * Associates the specified session data with the given key if the key is currently mapped to the given value. This |
| * method provides an atomic compare-and-update of some key's value. |
| * |
| * @param key The key under which to store the session data, must not be {@code null}. |
| * @param oldValue The expected data currently associated with the key, may be {@code null}. |
| * @param newValue The data to associate with the key, may be {@code null} to remove the mapping. |
| * @return {@code true} if the key mapping was successfully updated from the old value to the new value, |
| * {@code false} if the current key mapping didn't match the expected value and was not updated. |
| */ |
| boolean set( Object key, Object oldValue, Object newValue ); |
| |
| /** |
| * Gets the session data associated with the specified key. |
| * |
| * @param key The key for which to retrieve the session data, must not be {@code null}. |
| * @return The session data associated with the key or {@code null} if none. |
| */ |
| Object get( Object key ); |
| |
| } |