| /* |
| * |
| * 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.server.protocol.v0_10; |
| |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class CreditCreditManager implements FlowCreditManager_0_10 |
| { |
| private static final Logger LOG = LoggerFactory.getLogger(CreditCreditManager.class); |
| private volatile long _bytesCredit; |
| private volatile long _messageCredit; |
| |
| public CreditCreditManager(long bytesCredit, long messageCredit) |
| { |
| _bytesCredit = bytesCredit; |
| _messageCredit = messageCredit; |
| } |
| |
| @Override |
| public synchronized void restoreCredit(final long messageCredit, final long bytesCredit) |
| { |
| } |
| |
| |
| @Override |
| public synchronized void addCredit(final long messageCredit, final long bytesCredit) |
| { |
| |
| if(_messageCredit >= 0L) |
| { |
| if(messageCredit == INFINITE_CREDIT) |
| { |
| _messageCredit = -1L; |
| } |
| else |
| { |
| _messageCredit += messageCredit; |
| if (_messageCredit < 0L) |
| { |
| LOG.warn("Message credit wraparound: attempt to add {} message credit to existing total of {}", |
| messageCredit, |
| _messageCredit - messageCredit); |
| _messageCredit = Long.MAX_VALUE; |
| } |
| } |
| } |
| |
| if(_bytesCredit >= 0L) |
| { |
| if(bytesCredit == INFINITE_CREDIT) |
| { |
| _bytesCredit = -1L; |
| } |
| else |
| { |
| _bytesCredit += bytesCredit; |
| if (_bytesCredit < 0L) |
| { |
| LOG.warn("Bytes credit wraparound: attempt to add {} bytes credit to existing total of {}", |
| bytesCredit, |
| _bytesCredit - bytesCredit); |
| _bytesCredit = Long.MAX_VALUE; |
| } |
| } |
| } |
| } |
| |
| @Override |
| public synchronized void clearCredit() |
| { |
| _bytesCredit = 0L; |
| _messageCredit = 0L; |
| } |
| |
| |
| @Override |
| public synchronized boolean hasCredit() |
| { |
| // Note !=, if credit is < 0 that indicates infinite credit |
| return (_bytesCredit != 0L && _messageCredit != 0L); |
| } |
| |
| @Override |
| public synchronized boolean useCreditForMessage(long msgSize) |
| { |
| if(_messageCredit >= 0L) |
| { |
| if(_messageCredit > 0) |
| { |
| if(_bytesCredit < 0L) |
| { |
| _messageCredit--; |
| |
| return true; |
| } |
| else if(msgSize <= _bytesCredit) |
| { |
| _messageCredit--; |
| _bytesCredit -= msgSize; |
| |
| return true; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| else |
| { |
| return false; |
| } |
| } |
| else if(_bytesCredit >= 0L) |
| { |
| if(msgSize <= _bytesCredit) |
| { |
| _bytesCredit -= msgSize; |
| |
| return true; |
| } |
| else |
| { |
| return false; |
| } |
| |
| } |
| else |
| { |
| return true; |
| } |
| |
| } |
| |
| } |