QPID-6294 : [Java Client] Allow use of 0 prefetch in AMQP 0-8/9/9-1

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1648987 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 57 insertions, 18 deletions

diff --git a/qpid/java/client/src/main/java/org/apache/qpid/client/AMQSession_0_8.java b/qpid/java/client/src/main/java/org/apache/qpid/client/AMQSession_0_8.java
index d86a2739f2..bb0f0d9b13 100644
--- a/qpid/java/client/src/main/java/org/apache/qpid/client/AMQSession_0_8.java
+++ b/qpid/java/client/src/main/java/org/apache/qpid/client/AMQSession_0_8.java
@@ -824,12 +824,13 @@ public class AMQSession_0_8 extends AMQSession<BasicMessageConsumer_0_8, BasicMe
             throws AMQException, FailoverException
     {
         _currentPrefetch.set(0);
-        BasicQosBody basicQosBody = getProtocolHandler().getMethodRegistry().createBasicQosBody(sizePrefetch, messagePrefetch, false);
-
-        // todo send low water mark when protocol allows.
-        // todo Be aware of possible changes to parameter order as versions change.
-        getProtocolHandler().syncWrite(basicQosBody.generateFrame(getChannelId()), BasicQosOkBody.class);
+        if(messagePrefetch > 0 || sizePrefetch > 0)
+        {
+            BasicQosBody basicQosBody =
+                    getProtocolHandler().getMethodRegistry().createBasicQosBody(sizePrefetch, messagePrefetch, false);
 
+            getProtocolHandler().syncWrite(basicQosBody.generateFrame(getChannelId()), BasicQosOkBody.class);
+        }
     }
 
 
@@ -842,13 +843,17 @@ public class AMQSession_0_8 extends AMQSession<BasicMessageConsumer_0_8, BasicMe
                     public Boolean execute() throws AMQException, FailoverException
                     {
                         int currentPrefetch = _currentPrefetch.get();
-                        if (currentPrefetch >= getPrefetch())
+                        if (currentPrefetch >= getPrefetch() && getPrefetch() >= 0)
                         {
                             BasicQosBody basicQosBody = getProtocolHandler().getMethodRegistry()
                                     .createBasicQosBody(0, currentPrefetch + 1, false);
 
                             getProtocolHandler().syncWrite(basicQosBody.generateFrame(getChannelId()),
                                                            BasicQosOkBody.class);
+                            if(currentPrefetch == 0 && !isSuspended())
+                            {
+                                sendSuspendChannel(false);
+                            }
                             _creditChanged.set(true);
                             return true;
                         }
@@ -863,8 +868,7 @@ public class AMQSession_0_8 extends AMQSession<BasicMessageConsumer_0_8, BasicMe
 
     protected void reduceCreditAfterAcknowledge() throws AMQException
     {
-        int acknowledgeMode = getAcknowledgeMode();
-        boolean manageCredit = acknowledgeMode == javax.jms.Session.CLIENT_ACKNOWLEDGE || acknowledgeMode == javax.jms.Session.SESSION_TRANSACTED;
+        boolean manageCredit = isManagingCredit();
 
         if(manageCredit && _creditChanged.compareAndSet(true,false))
         {
@@ -873,18 +877,40 @@ public class AMQSession_0_8 extends AMQSession<BasicMessageConsumer_0_8, BasicMe
                     {
                         public Void execute() throws AMQException, FailoverException
                         {
-                            BasicQosBody basicQosBody =
-                                    getProtocolHandler().getMethodRegistry()
-                                            .createBasicQosBody(0, getPrefetch(), false);
+                            int prefetch = getPrefetch();
+                            if(prefetch == 0)
+                            {
+                                sendSuspendChannel(true);
+                            }
+                            else
+                            {
+                                BasicQosBody basicQosBody =
+                                        getProtocolHandler().getMethodRegistry()
+                                                .createBasicQosBody(0, prefetch == -1 ? 0 : prefetch, false);
 
-                            getProtocolHandler().syncWrite(basicQosBody.generateFrame(getChannelId()),
-                                                           BasicQosOkBody.class);
+                                getProtocolHandler().syncWrite(basicQosBody.generateFrame(getChannelId()),
+                                                               BasicQosOkBody.class);
+                            }
                             return null;
                         }
                     }, getProtocolHandler().getConnection()).execute();
         }
     }
 
+    protected void reduceCreditInPostDeliver()
+    {
+        int acknowledgeMode = getAcknowledgeMode();
+        boolean manageCredit = (acknowledgeMode == AUTO_ACKNOWLEDGE || acknowledgeMode == DUPS_OK_ACKNOWLEDGE) && getPrefetch() == 0;
+
+        if(manageCredit && _creditChanged.compareAndSet(true,false))
+        {
+            ChannelFlowBody body = getMethodRegistry().createChannelFlowBody(false);
+            AMQFrame channelFlowFrame = body.generateFrame(getChannelId());
+            getProtocolHandler().writeFrame(channelFlowFrame, true);
+        }
+    }
+
+
     protected void updateCurrentPrefetch(int delta)
     {
         _currentPrefetch.addAndGet(delta);
@@ -1414,6 +1440,15 @@ public class AMQSession_0_8 extends AMQSession<BasicMessageConsumer_0_8, BasicMe
         }
     }
 
+    boolean isManagingCredit()
+    {
+        int acknowledgeMode = getAcknowledgeMode();
+        return acknowledgeMode == CLIENT_ACKNOWLEDGE
+               || acknowledgeMode == SESSION_TRANSACTED
+               || ((acknowledgeMode == AUTO_ACKNOWLEDGE || acknowledgeMode == DUPS_OK_ACKNOWLEDGE) && getPrefetch() == 0);
+    }
+
+
     public boolean isFlowBlocked()
     {
         synchronized (_flowControl)
diff --git a/qpid/java/client/src/main/java/org/apache/qpid/client/BasicMessageConsumer_0_8.java b/qpid/java/client/src/main/java/org/apache/qpid/client/BasicMessageConsumer_0_8.java
index 6718121e6b..3cc50512ed 100644
--- a/qpid/java/client/src/main/java/org/apache/qpid/client/BasicMessageConsumer_0_8.java
+++ b/qpid/java/client/src/main/java/org/apache/qpid/client/BasicMessageConsumer_0_8.java
@@ -22,7 +22,6 @@ package org.apache.qpid.client;
 
 import javax.jms.JMSException;
 import javax.jms.Message;
-import javax.jms.Session;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -170,8 +169,7 @@ public class BasicMessageConsumer_0_8 extends BasicMessageConsumer<UnprocessedMe
     @Override
     public Message receive(final long l) throws JMSException
     {
-        int acknowledgeMode = getSession().getAcknowledgeMode();
-        boolean manageCredit = acknowledgeMode == Session.CLIENT_ACKNOWLEDGE || acknowledgeMode == Session.SESSION_TRANSACTED;
+        boolean manageCredit = getSession().isManagingCredit();
         boolean creditModified = false;
         try
         {
@@ -199,8 +197,7 @@ public class BasicMessageConsumer_0_8 extends BasicMessageConsumer<UnprocessedMe
     @Override
     public Message receiveNoWait() throws JMSException
     {
-        int acknowledgeMode = getSession().getAcknowledgeMode();
-        boolean manageCredit = acknowledgeMode == Session.CLIENT_ACKNOWLEDGE || acknowledgeMode == Session.SESSION_TRANSACTED;
+        boolean manageCredit = getSession().isManagingCredit();
         boolean creditModified = false;
         try
         {
@@ -228,4 +225,11 @@ public class BasicMessageConsumer_0_8 extends BasicMessageConsumer<UnprocessedMe
             throw new JMSAMQException(e);
         }
     }
+
+
+    void postDeliver(AbstractJMSMessage msg)
+    {
+        getSession().reduceCreditInPostDeliver();
+        super.postDeliver(msg);
+    }
 }