| /* |
| * |
| * 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. |
| * |
| */ |
| package org.apache.qpid.client; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.LinkedHashMap; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| public final class ChannelToSessionMap |
| { |
| private final AMQSession[] _fastAccessSessions = new AMQSession[16]; |
| private final LinkedHashMap<Integer, AMQSession> _slowAccessSessions = new LinkedHashMap<Integer, AMQSession>(); |
| private int _size = 0; |
| private static final int FAST_CHANNEL_ACCESS_MASK = 0xFFFFFFF0; |
| private AtomicInteger _idFactory = new AtomicInteger(0); |
| private int _maxChannelID; |
| private int _minChannelID; |
| |
| public AMQSession get(int channelId) |
| { |
| if ((channelId & FAST_CHANNEL_ACCESS_MASK) == 0) |
| { |
| return _fastAccessSessions[channelId]; |
| } |
| else |
| { |
| return _slowAccessSessions.get(channelId); |
| } |
| } |
| |
| public AMQSession put(int channelId, AMQSession session) |
| { |
| AMQSession oldVal; |
| if ((channelId & FAST_CHANNEL_ACCESS_MASK) == 0) |
| { |
| oldVal = _fastAccessSessions[channelId]; |
| _fastAccessSessions[channelId] = session; |
| } |
| else |
| { |
| oldVal = _slowAccessSessions.put(channelId, session); |
| } |
| if ((oldVal != null) && (session == null)) |
| { |
| _size--; |
| } |
| else if ((oldVal == null) && (session != null)) |
| { |
| _size++; |
| } |
| |
| return session; |
| |
| } |
| |
| public AMQSession remove(int channelId) |
| { |
| AMQSession session; |
| if ((channelId & FAST_CHANNEL_ACCESS_MASK) == 0) |
| { |
| session = _fastAccessSessions[channelId]; |
| _fastAccessSessions[channelId] = null; |
| } |
| else |
| { |
| session = _slowAccessSessions.remove(channelId); |
| } |
| |
| if (session != null) |
| { |
| _size--; |
| } |
| return session; |
| |
| } |
| |
| public Collection<AMQSession> values() |
| { |
| ArrayList<AMQSession> values = new ArrayList<AMQSession>(size()); |
| |
| for (int i = 0; i < 16; i++) |
| { |
| if (_fastAccessSessions[i] != null) |
| { |
| values.add(_fastAccessSessions[i]); |
| } |
| } |
| values.addAll(_slowAccessSessions.values()); |
| |
| return values; |
| } |
| |
| public int size() |
| { |
| return _size; |
| } |
| |
| public void clear() |
| { |
| _size = 0; |
| _slowAccessSessions.clear(); |
| for (int i = 0; i < 16; i++) |
| { |
| _fastAccessSessions[i] = null; |
| } |
| } |
| |
| /* |
| * Synchronized on whole method so that we don't need to consider the |
| * increment-then-reset path in too much detail |
| */ |
| public synchronized int getNextChannelId() |
| { |
| int id = _minChannelID; |
| |
| boolean done = false; |
| while (!done) |
| { |
| id = _idFactory.getAndIncrement(); |
| if (id == _maxChannelID) |
| { |
| //go back to the start |
| _idFactory.set(_minChannelID); |
| } |
| if ((id & FAST_CHANNEL_ACCESS_MASK) == 0) |
| { |
| done = (_fastAccessSessions[id] == null); |
| } |
| else |
| { |
| done = (!_slowAccessSessions.keySet().contains(id)); |
| } |
| } |
| |
| return id; |
| } |
| |
| public void setMaxChannelID(int maxChannelID) |
| { |
| _maxChannelID = maxChannelID; |
| } |
| |
| public void setMinChannelID(int minChannelID) |
| { |
| _minChannelID = minChannelID; |
| _idFactory.set(_minChannelID); |
| } |
| } |