1 files changed, 190 insertions, 0 deletions
diff --git a/qpid/java/broker-plugins/amqp-0-8-protocol/src/main/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManager.java b/qpid/java/broker-plugins/amqp-0-8-protocol/src/main/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManager.java
new file mode 100644
index 0000000000..a869a707e1
--- /dev/null
+++ b/qpid/java/broker-plugins/amqp-0-8-protocol/src/main/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManager.java
@@ -0,0 +1,190 @@
+/*
+*
+* 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_8;
+
+
+import org.apache.qpid.server.protocol.ServerProtocolEngine;
+import org.apache.qpid.server.flow.AbstractFlowCreditManager;
+import org.apache.qpid.server.flow.FlowCreditManager;
+
+public class Pre0_10CreditManager extends AbstractFlowCreditManager implements FlowCreditManager
+{
+
+    private final ServerProtocolEngine _protocolEngine;
+    private volatile long _bytesCreditLimit;
+    private volatile long _messageCreditLimit;
+
+    private volatile long _bytesCredit;
+    private volatile long _messageCredit;
+
+    public Pre0_10CreditManager(long bytesCreditLimit,
+                                long messageCreditLimit,
+                                ServerProtocolEngine protocolEngine)
+    {
+        _protocolEngine = protocolEngine;
+        _bytesCreditLimit = bytesCreditLimit;
+        _messageCreditLimit = messageCreditLimit;
+        _bytesCredit = bytesCreditLimit;
+        _messageCredit = messageCreditLimit;
+    }
+
+
+
+    public synchronized void setCreditLimits(final long bytesCreditLimit, final long messageCreditLimit)
+    {
+        long bytesCreditChange = bytesCreditLimit - _bytesCreditLimit;
+        long messageCreditChange = messageCreditLimit - _messageCreditLimit;
+
+
+
+        if(bytesCreditChange != 0L)
+        {
+            if(bytesCreditLimit == 0L)
+            {
+                _bytesCredit = 0;
+            }
+            else
+            {
+                _bytesCredit += bytesCreditChange;
+            }
+        }
+
+
+        if(messageCreditChange != 0L)
+        {
+            if(messageCreditLimit == 0L)
+            {
+                _messageCredit = 0;
+            }
+            else
+            {
+                _messageCredit += messageCreditChange;
+            }
+        }
+
+
+        _bytesCreditLimit = bytesCreditLimit;
+        _messageCreditLimit = messageCreditLimit;
+
+        setSuspended(!hasCredit());
+
+    }
+
+
+    public synchronized void restoreCredit(final long messageCredit, final long bytesCredit)
+    {
+        final long messageCreditLimit = _messageCreditLimit;
+        boolean notifyIncrease = true;
+        if(messageCreditLimit != 0L)
+        {
+            notifyIncrease = (_messageCredit != 0);
+            long newCredit = _messageCredit + messageCredit;
+            _messageCredit = newCredit > messageCreditLimit ? messageCreditLimit : newCredit;
+        }
+
+
+        final long bytesCreditLimit = _bytesCreditLimit;
+        if(bytesCreditLimit != 0L)
+        {
+            long newCredit = _bytesCredit + bytesCredit;
+            _bytesCredit = newCredit > bytesCreditLimit ? bytesCreditLimit : newCredit;
+            if(notifyIncrease && bytesCredit>0)
+            {
+                notifyIncreaseBytesCredit();
+            }
+        }
+
+
+
+        setSuspended(!hasCredit());
+
+    }
+
+    public synchronized boolean hasCredit()
+    {
+        return (_bytesCreditLimit == 0L || _bytesCredit > 0)
+                && (_messageCreditLimit == 0L || _messageCredit > 0)
+                && !_protocolEngine.isTransportBlockedForWriting();
+    }
+
+    public synchronized boolean useCreditForMessage(final long msgSize)
+    {
+        if (_protocolEngine.isTransportBlockedForWriting())
+        {
+            setSuspended(true);
+            return false;
+        }
+        else if(_messageCreditLimit != 0L)
+        {
+            if(_messageCredit != 0L)
+            {
+                if(_bytesCreditLimit == 0L)
+                {
+                    _messageCredit--;
+
+                    return true;
+                }
+                else
+                {
+                    if((_bytesCredit >= msgSize) || (_bytesCredit == _bytesCreditLimit))
+                    {
+                        _messageCredit--;
+                        _bytesCredit -= msgSize;
+
+                        return true;
+                    }
+                    else
+                    {
+                        return false;
+                    }
+                }
+            }
+            else
+            {
+                setSuspended(true);
+                return false;
+            }
+        }
+        else
+        {
+            if(_bytesCreditLimit == 0L)
+            {
+
+                return true;
+            }
+            else
+            {
+                if((_bytesCredit >= msgSize) || (_bytesCredit == _bytesCreditLimit))
+                {
+                    _bytesCredit -= msgSize;
+
+                    return true;
+                }
+                else
+                {
+                    return false;
+                }
+            }
+
+        }
+
+    }
+}