1 files changed, 116 insertions, 0 deletions
diff --git a/trunk/qpid/cpp/src/qpid/cluster/OutputInterceptor.cpp b/trunk/qpid/cpp/src/qpid/cluster/OutputInterceptor.cpp
new file mode 100644
index 0000000000..cb75fe5561
--- /dev/null
+++ b/trunk/qpid/cpp/src/qpid/cluster/OutputInterceptor.cpp
@@ -0,0 +1,116 @@
+/*
+ *
+ * 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.
+ *
+ */
+#include "qpid/cluster/OutputInterceptor.h"
+#include "qpid/cluster/Connection.h"
+#include "qpid/cluster/Cluster.h"
+#include "qpid/framing/ClusterConnectionDeliverDoOutputBody.h"
+#include "qpid/framing/AMQFrame.h"
+#include "qpid/log/Statement.h"
+#include <boost/current_function.hpp>
+
+
+namespace qpid {
+namespace cluster {
+
+using namespace framing;
+using namespace std;
+
+NoOpConnectionOutputHandler OutputInterceptor::discardHandler;
+
+OutputInterceptor::OutputInterceptor(Connection& p, sys::ConnectionOutputHandler& h)
+    : parent(p), closing(false), next(&h), sendMax(1), sent(0), sentDoOutput(false)
+{}
+
+void OutputInterceptor::send(framing::AMQFrame& f) {
+    sys::Mutex::ScopedLock l(lock);
+    next->send(f);
+}
+
+void OutputInterceptor::activateOutput() {
+    if (parent.isCatchUp()) {
+        sys::Mutex::ScopedLock l(lock);
+        next->activateOutput();
+    }
+    else
+        sendDoOutput(sendMax);
+}
+
+void OutputInterceptor::abort() {
+    sys::Mutex::ScopedLock l(lock);
+    if (parent.isLocal()) {
+        next->abort();
+    }
+}
+
+void OutputInterceptor::giveReadCredit(int32_t credit) {
+    sys::Mutex::ScopedLock l(lock);
+    next->giveReadCredit(credit);
+}
+
+// Called in write thread when the IO layer has no more data to write.
+// We do nothing in the write thread, we run doOutput only on delivery
+// of doOutput requests.
+bool OutputInterceptor::doOutput() { return false; }
+
+// Send output up to limit, calculate new limit. 
+void OutputInterceptor::deliverDoOutput(uint32_t limit) {
+    sentDoOutput = false;
+    sendMax = limit;
+    size_t newLimit = limit;
+    if (parent.isLocal()) {
+        size_t buffered = getBuffered();
+        if (buffered == 0 && sent == sendMax) // Could have sent more, increase the limit.
+            newLimit = sendMax*2; 
+        else if (buffered > 0 && sent > 1) // Data left unsent, reduce the limit.
+            newLimit = sent-1;
+    }
+    sent = 0;
+    while (sent < limit && parent.getBrokerConnection().doOutput())
+        ++sent;
+    if (sent == limit) sendDoOutput(newLimit);
+}
+
+void OutputInterceptor::sendDoOutput(size_t newLimit) {
+    if (parent.isLocal() && !sentDoOutput && !closing) {
+        sentDoOutput = true;
+        parent.getCluster().getMulticast().mcastControl(
+            ClusterConnectionDeliverDoOutputBody(ProtocolVersion(), newLimit),
+            parent.getId());
+    }
+}
+
+void OutputInterceptor::closeOutput() {
+    sys::Mutex::ScopedLock l(lock);
+    closing = true;
+    next = &discardHandler;
+}
+
+void OutputInterceptor::close() {
+    sys::Mutex::ScopedLock l(lock);
+    next->close();
+}
+
+size_t OutputInterceptor::getBuffered() const {
+    sys::Mutex::ScopedLock l(lock);
+    return next->getBuffered();
+}
+
+}} // namespace qpid::cluster