| // |
| // ======================================================================== |
| // Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd. |
| // ------------------------------------------------------------------------ |
| // All rights reserved. This program and the accompanying materials |
| // are made available under the terms of the Eclipse Public License v1.0 |
| // and Apache License v2.0 which accompanies this distribution. |
| // |
| // The Eclipse Public License is available at |
| // http://www.eclipse.org/legal/epl-v10.html |
| // |
| // The Apache License v2.0 is available at |
| // http://www.opensource.org/licenses/apache2.0.php |
| // |
| // You may elect to redistribute this code under either of these licenses. |
| // ======================================================================== |
| // |
| |
| package org.eclipse.jetty.util; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Enumeration; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| public class AttributesMap implements Attributes |
| { |
| private final AtomicReference<ConcurrentMap<String, Object>> _map = new AtomicReference<>(); |
| |
| public AttributesMap() |
| { |
| } |
| |
| public AttributesMap(AttributesMap attributes) |
| { |
| ConcurrentMap<String, Object> map = attributes.map(); |
| if (map != null) |
| _map.set(new ConcurrentHashMap<>(map)); |
| } |
| |
| private ConcurrentMap<String, Object> map() |
| { |
| return _map.get(); |
| } |
| |
| private ConcurrentMap<String, Object> ensureMap() |
| { |
| while (true) |
| { |
| ConcurrentMap<String, Object> map = map(); |
| if (map != null) |
| return map; |
| map = new ConcurrentHashMap<>(); |
| if (_map.compareAndSet(null, map)) |
| return map; |
| } |
| } |
| |
| @Override |
| public void removeAttribute(String name) |
| { |
| Map<String, Object> map = map(); |
| if (map != null) |
| map.remove(name); |
| } |
| |
| @Override |
| public void setAttribute(String name, Object attribute) |
| { |
| if (attribute == null) |
| removeAttribute(name); |
| else |
| ensureMap().put(name, attribute); |
| } |
| |
| @Override |
| public Object getAttribute(String name) |
| { |
| Map<String, Object> map = map(); |
| return map == null ? null : map.get(name); |
| } |
| |
| @Override |
| public Enumeration<String> getAttributeNames() |
| { |
| return Collections.enumeration(getAttributeNameSet()); |
| } |
| |
| public Set<String> getAttributeNameSet() |
| { |
| return keySet(); |
| } |
| |
| public Set<Map.Entry<String, Object>> getAttributeEntrySet() |
| { |
| Map<String, Object> map = map(); |
| return map == null ? Collections.<Map.Entry<String, Object>>emptySet() : map.entrySet(); |
| } |
| |
| public static Enumeration<String> getAttributeNamesCopy(Attributes attrs) |
| { |
| if (attrs instanceof AttributesMap) |
| return Collections.enumeration(((AttributesMap)attrs).keySet()); |
| |
| List<String> names = new ArrayList<>(); |
| names.addAll(Collections.list(attrs.getAttributeNames())); |
| return Collections.enumeration(names); |
| } |
| |
| @Override |
| public void clearAttributes() |
| { |
| Map<String, Object> map = map(); |
| if (map != null) |
| map.clear(); |
| } |
| |
| public int size() |
| { |
| Map<String, Object> map = map(); |
| return map == null ? 0 : map.size(); |
| } |
| |
| @Override |
| public String toString() |
| { |
| Map<String, Object> map = map(); |
| return map == null ? "{}" : map.toString(); |
| } |
| |
| private Set<String> keySet() |
| { |
| Map<String, Object> map = map(); |
| return map == null ? Collections.<String>emptySet() : map.keySet(); |
| } |
| |
| public void addAll(Attributes attributes) |
| { |
| Enumeration<String> e = attributes.getAttributeNames(); |
| while (e.hasMoreElements()) |
| { |
| String name = e.nextElement(); |
| setAttribute(name, attributes.getAttribute(name)); |
| } |
| } |
| } |