1 files changed, 213 insertions, 0 deletions
diff --git a/java/broker/src/main/java/org/apache/qpid/server/flow/WindowCreditManager.java b/java/broker/src/main/java/org/apache/qpid/server/flow/WindowCreditManager.java
new file mode 100644
index 0000000000..10f578551a
--- /dev/null
+++ b/java/broker/src/main/java/org/apache/qpid/server/flow/WindowCreditManager.java
@@ -0,0 +1,213 @@
+/*
+ *
+ * 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.flow;
+
+import org.apache.qpid.server.message.ServerMessage;
+
+public class WindowCreditManager extends AbstractFlowCreditManager implements FlowCreditManager_0_10
+{
+    private volatile long _bytesCreditLimit;
+    private volatile long _messageCreditLimit;
+
+    private volatile long _bytesUsed;
+    private volatile long _messageUsed;
+
+     public WindowCreditManager()
+     {
+         this(0L, 0L);
+     }
+
+    public WindowCreditManager(long bytesCreditLimit, long messageCreditLimit)
+    {
+        _bytesCreditLimit = bytesCreditLimit;
+        _messageCreditLimit = messageCreditLimit;
+        setSuspended(!hasCredit());
+
+    }
+
+
+    public synchronized void setCreditLimits(final long bytesCreditLimit, final long messageCreditLimit)
+    {
+        _bytesCreditLimit = bytesCreditLimit;
+        _messageCreditLimit = messageCreditLimit;
+
+        setSuspended(!hasCredit());
+
+    }
+
+
+    public long getMessageCredit()
+    {
+         return _messageCreditLimit == -1L
+                    ? Long.MAX_VALUE
+                    : _messageUsed < _messageCreditLimit ? _messageCreditLimit - _messageUsed : 0L;
+    }
+
+    public long getBytesCredit()
+    {
+        return _bytesCreditLimit == -1L
+                    ? Long.MAX_VALUE
+                    : _bytesUsed < _bytesCreditLimit ? _bytesCreditLimit - _bytesUsed : 0L;
+    }
+
+    public synchronized void restoreCredit(final long messageCredit, final long bytesCredit)
+    {
+        boolean notifyIncrease = true;
+        if(_messageCreditLimit > 0L)
+        {
+            notifyIncrease = (_messageUsed != _messageCreditLimit);
+            _messageUsed -= messageCredit;
+
+            //TODO log warning
+            if(_messageUsed < 0L)
+            {
+                _messageUsed = 0;
+            }
+        }
+
+
+
+        if(_bytesCreditLimit > 0L)
+        {
+            notifyIncrease = notifyIncrease && bytesCredit>0;
+            _bytesUsed -= bytesCredit;
+
+            //TODO log warning
+            if(_bytesUsed < 0L)
+            {
+                _bytesUsed = 0;
+            }
+
+            if(notifyIncrease)
+            {
+                notifyIncreaseBytesCredit();
+            }
+        }
+
+
+
+        setSuspended(!hasCredit());
+
+    }
+
+
+
+    public synchronized boolean hasCredit()
+    {
+        return (_bytesCreditLimit < 0L || _bytesCreditLimit > _bytesUsed)
+                && (_messageCreditLimit < 0L || _messageCreditLimit > _messageUsed);
+    }
+
+    public synchronized boolean useCreditForMessage(final ServerMessage msg)
+    {
+        if(_messageCreditLimit >= 0L)
+        {
+            if(_messageUsed < _messageCreditLimit)
+            {
+                if(_bytesCreditLimit < 0L)
+                {
+                    _messageUsed++;
+
+                    return true;
+                }
+                else if(_bytesUsed + msg.getSize() <= _bytesCreditLimit)
+                {
+                    _messageUsed++;
+                    _bytesUsed += msg.getSize();
+
+                    return true;
+                }
+                else
+                {
+                    //setSuspended(true);
+                    return false;
+                }
+            }
+            else
+            {
+                setSuspended(true);
+                return false;
+            }
+        }
+        else if(_bytesCreditLimit >= 0L)
+        {
+            if(_bytesUsed + msg.getSize() <= _bytesCreditLimit)
+            {
+                 _bytesUsed += msg.getSize();
+
+                return true;
+            }
+            else
+            {
+                //setSuspended(true);
+                return false;
+            }
+
+        }
+        else
+        {
+            return true;
+        }
+
+    }
+
+    public void stop()
+    {
+        if(_bytesCreditLimit > 0)
+        {
+            _bytesCreditLimit = 0;
+        }
+        if(_messageCreditLimit > 0)
+        {
+            _messageCreditLimit = 0;
+        }
+
+    }
+
+    public synchronized void addCredit(long count, long bytes)
+    {
+        if(bytes > 0)
+        {
+            _bytesCreditLimit += bytes;
+        }
+        else if(bytes == -1)
+        {
+            _bytesCreditLimit = -1;
+        }
+
+
+        if(count > 0)
+        {
+            _messageCreditLimit += count;
+        }
+        else if(count == -1)
+        {
+            _messageCreditLimit = -1;
+        }
+    }
+
+    public void clearCredit()
+    {
+        _bytesCreditLimit = 0l;
+        _messageCreditLimit = 0l;
+        setSuspended(true);
+    }
+}