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Diffstat (limited to 'qpid/java/client/src/main/java/org/apache/qpid/client/ChannelToSessionMap.java')
| -rw-r--r-- | qpid/java/client/src/main/java/org/apache/qpid/client/ChannelToSessionMap.java | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/qpid/java/client/src/main/java/org/apache/qpid/client/ChannelToSessionMap.java b/qpid/java/client/src/main/java/org/apache/qpid/client/ChannelToSessionMap.java new file mode 100644 index 0000000000..2fdb35de49 --- /dev/null +++ b/qpid/java/client/src/main/java/org/apache/qpid/client/ChannelToSessionMap.java @@ -0,0 +1,167 @@ +/* + * + * 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); + } +}
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