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/*
*
* 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 "ReplicatingSubscription.h"
#include "Logging.h"
#include "qpid/broker/Queue.h"
#include "qpid/framing/AMQFrame.h"
#include "qpid/framing/MessageTransferBody.h"
#include "qpid/log/Statement.h"
namespace qpid {
namespace ha {
using namespace framing;
using namespace broker;
using namespace std;
// FIXME aconway 2011-11-28: review all arugment names, prefixes etc.
// Do we want a common HA prefix?
const string ReplicatingSubscription::QPID_REPLICATING_SUBSCRIPTION("qpid.replicating-subscription");
const string ReplicatingSubscription::QPID_HIGH_SEQUENCE_NUMBER("qpid.high_sequence_number");
const string ReplicatingSubscription::QPID_LOW_SEQUENCE_NUMBER("qpid.low_sequence_number");
const string DOLLAR("$");
const string INTERNAL("-internal");
class ReplicationStateInitialiser
{
public:
ReplicationStateInitialiser(
qpid::framing::SequenceSet& r,
const qpid::framing::SequenceNumber& s,
const qpid::framing::SequenceNumber& e) : results(r), start(s), end(e)
{
results.add(start, end);
}
void operator()(const QueuedMessage& message) {
if (message.position < start) {
//replica does not have a message that should still be on the queue
QPID_LOG(warning, "HA: Replica missing message " << QueuePos(message));
} else if (message.position >= start && message.position <= end) {
//i.e. message is within the intial range and has not been dequeued, so remove it from the results
results.remove(message.position);
} //else message has not been seen by replica yet so can be ignored here
}
private:
qpid::framing::SequenceSet& results;
const qpid::framing::SequenceNumber start;
const qpid::framing::SequenceNumber end;
};
string mask(const string& in)
{
return DOLLAR + in + INTERNAL;
}
boost::shared_ptr<broker::SemanticState::ConsumerImpl>
ReplicatingSubscription::Factory::create(
SemanticState* parent,
const string& name,
Queue::shared_ptr queue,
bool ack,
bool acquire,
bool exclusive,
const string& tag,
const string& resumeId,
uint64_t resumeTtl,
const framing::FieldTable& arguments
) {
return boost::shared_ptr<broker::SemanticState::ConsumerImpl>(
new ReplicatingSubscription(parent, name, queue, ack, acquire, exclusive, tag, resumeId, resumeTtl, arguments));
}
ReplicatingSubscription::ReplicatingSubscription(
SemanticState* parent,
const string& name,
Queue::shared_ptr queue,
bool ack,
bool acquire,
bool exclusive,
const string& tag,
const string& resumeId,
uint64_t resumeTtl,
const framing::FieldTable& arguments
) : ConsumerImpl(parent, name, queue, ack, acquire, exclusive, tag,
resumeId, resumeTtl, arguments),
events(new Queue(mask(name))),
consumer(new DelegatingConsumer(*this))
{
QPID_LOG(debug, "HA: Replicating subscription " << name << " to " << queue->getName());
// FIXME aconway 2011-11-25: string constants.
if (arguments.isSet("qpid.high_sequence_number")) {
qpid::framing::SequenceNumber hwm = arguments.getAsInt("qpid.high_sequence_number");
qpid::framing::SequenceNumber lwm;
if (arguments.isSet("qpid.low_sequence_number")) {
lwm = arguments.getAsInt("qpid.low_sequence_number");
} else {
lwm = hwm;
}
qpid::framing::SequenceNumber oldest;
if (queue->getOldest(oldest)) {
if (oldest >= hwm) {
range.add(lwm, --oldest);
} else if (oldest >= lwm) {
ReplicationStateInitialiser initialiser(range, lwm, hwm);
queue->eachMessage(initialiser);
} else { //i.e. have older message on master than is reported to exist on replica
QPID_LOG(warning, "HA: Replica missing message on master");
}
} else {
//local queue (i.e. master) is empty
range.add(lwm, queue->getPosition());
}
QPID_LOG(debug, "HA: Initial set of dequeues for " << queue->getName() << " are " << range
<< " (lwm=" << lwm << ", hwm=" << hwm << ", current=" << queue->getPosition() << ")");
//set position of 'cursor'
position = hwm;
}
}
bool ReplicatingSubscription::deliver(QueuedMessage& m)
{
return ConsumerImpl::deliver(m);
}
void ReplicatingSubscription::cancel()
{
getQueue()->removeObserver(boost::dynamic_pointer_cast<QueueObserver>(shared_from_this()));
}
ReplicatingSubscription::~ReplicatingSubscription() {}
//called before we get notified of the message being available and
//under the message lock in the queue
void ReplicatingSubscription::enqueued(const QueuedMessage& m)
{
QPID_LOG(trace, "HA: Enqueued message " << QueuePos(m));
//delay completion
m.payload->getIngressCompletion().startCompleter();
}
void ReplicatingSubscription::generateDequeueEvent()
{
string buf(range.encodedSize(),'\0');
framing::Buffer buffer(&buf[0], buf.size());
range.encode(buffer);
range.clear();
buffer.reset();
//generate event message
boost::intrusive_ptr<Message> event = new Message();
AMQFrame method((MessageTransferBody(ProtocolVersion(), string(), 0, 0)));
AMQFrame header((AMQHeaderBody()));
AMQFrame content((AMQContentBody()));
content.castBody<AMQContentBody>()->decode(buffer, buffer.getSize());
header.setBof(false);
header.setEof(false);
header.setBos(true);
header.setEos(true);
content.setBof(false);
content.setEof(true);
content.setBos(true);
content.setEos(true);
event->getFrames().append(method);
event->getFrames().append(header);
event->getFrames().append(content);
DeliveryProperties* props = event->getFrames().getHeaders()->get<DeliveryProperties>(true);
props->setRoutingKey("dequeue-event");
events->deliver(event);
}
//called after the message has been removed from the deque and under
//the message lock in the queue
void ReplicatingSubscription::dequeued(const QueuedMessage& m)
{
{
sys::Mutex::ScopedLock l(lock);
range.add(m.position);
// FIXME aconway 2011-11-29: q[pos]
QPID_LOG(trace, "HA: Updated dequeue event to include " << QueuePos(m) << "; subscription is at " << position);
}
notify();
if (m.position > position) {
m.payload->getIngressCompletion().finishCompleter();
QPID_LOG(trace, "HA: Completed " << QueuePos(m) << " early due to dequeue");
}
}
bool ReplicatingSubscription::doDispatch()
{
{
sys::Mutex::ScopedLock l(lock);
if (!range.empty()) {
generateDequeueEvent();
}
}
bool r1 = events->dispatch(consumer);
bool r2 = ConsumerImpl::doDispatch();
return r1 || r2;
}
ReplicatingSubscription::DelegatingConsumer::DelegatingConsumer(ReplicatingSubscription& c) : Consumer(c.getName(), true), delegate(c) {}
ReplicatingSubscription::DelegatingConsumer::~DelegatingConsumer() {}
bool ReplicatingSubscription::DelegatingConsumer::deliver(QueuedMessage& m)
{
return delegate.deliver(m);
}
void ReplicatingSubscription::DelegatingConsumer::notify() { delegate.notify(); }
bool ReplicatingSubscription::DelegatingConsumer::filter(boost::intrusive_ptr<Message> msg) { return delegate.filter(msg); }
bool ReplicatingSubscription::DelegatingConsumer::accept(boost::intrusive_ptr<Message> msg) { return delegate.accept(msg); }
OwnershipToken* ReplicatingSubscription::DelegatingConsumer::getSession() { return delegate.getSession(); }
}} // namespace qpid::broker
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