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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 "qpid/replication/ReplicatingEventListener.h"
#include "qpid/replication/constants.h"
#include "qpid/broker/Broker.h"
#include "qpid/broker/DeliverableMessage.h"
#include "qpid/broker/QueueEvents.h"
#include "qpid/framing/AMQFrame.h"
#include "qpid/framing/FrameHandler.h"
#include "qpid/framing/MessageTransferBody.h"
#include "qpid/log/Statement.h"
namespace qpid {
namespace replication {
using namespace qpid::broker;
using namespace qpid::framing;
using namespace qpid::replication::constants;
void ReplicatingEventListener::handle(QueueEvents::Event event)
{
switch (event.type) {
case QueueEvents::ENQUEUE:
deliverEnqueueMessage(event.msg);
QPID_LOG(debug, "Queuing 'enqueue' event on " << event.msg.queue->getName() << " for replication");
break;
case QueueEvents::DEQUEUE:
deliverDequeueMessage(event.msg);
QPID_LOG(debug, "Queuing 'dequeue' event from " << event.msg.queue->getName() << " for replication, (from position "
<< event.msg.position << ")");
break;
}
}
namespace {
const std::string EMPTY;
}
void ReplicatingEventListener::deliverDequeueMessage(const QueuedMessage& dequeued)
{
FieldTable headers;
headers.setString(REPLICATION_TARGET_QUEUE, dequeued.queue->getName());
headers.setInt(REPLICATION_EVENT_TYPE, DEQUEUE);
headers.setInt(DEQUEUED_MESSAGE_POSITION, dequeued.position);
boost::intrusive_ptr<Message> msg(createMessage(headers));
DeliveryProperties* props = msg->getFrames().getHeaders()->get<DeliveryProperties>(true);
props->setRoutingKey(dequeued.queue->getName());
route(msg);
}
void ReplicatingEventListener::deliverEnqueueMessage(const QueuedMessage& enqueued)
{
boost::intrusive_ptr<Message> msg(cloneMessage(*(enqueued.queue), enqueued.payload));
FieldTable& headers = msg->getProperties<MessageProperties>()->getApplicationHeaders();
headers.setString(REPLICATION_TARGET_QUEUE, enqueued.queue->getName());
headers.setInt(REPLICATION_EVENT_TYPE, ENQUEUE);
headers.setInt(QUEUE_MESSAGE_POSITION,enqueued.position);
route(msg);
}
void ReplicatingEventListener::route(boost::intrusive_ptr<qpid::broker::Message> msg)
{
try {
if (exchange) {
DeliverableMessage deliverable(msg);
exchange->route(deliverable, msg->getRoutingKey(), msg->getApplicationHeaders());
} else if (queue) {
queue->deliver(msg);
} else {
QPID_LOG(error, "Cannot route replication event, neither replication queue nor exchange configured");
}
} catch (const std::exception& e) {
QPID_LOG(error, "Error enqueing replication event: " << e.what());
}
}
boost::intrusive_ptr<Message> ReplicatingEventListener::createMessage(const FieldTable& headers)
{
boost::intrusive_ptr<Message> msg(new Message());
AMQFrame method((MessageTransferBody(ProtocolVersion(), EMPTY, 0, 0)));
AMQFrame header((AMQHeaderBody()));
header.setBof(false);
header.setEof(true);
header.setBos(true);
header.setEos(true);
msg->getFrames().append(method);
msg->getFrames().append(header);
MessageProperties* props = msg->getFrames().getHeaders()->get<MessageProperties>(true);
props->setApplicationHeaders(headers);
return msg;
}
struct AppendingHandler : FrameHandler
{
boost::intrusive_ptr<Message> msg;
AppendingHandler(boost::intrusive_ptr<Message> m) : msg(m) {}
void handle(AMQFrame& f)
{
msg->getFrames().append(f);
}
};
boost::intrusive_ptr<Message> ReplicatingEventListener::cloneMessage(Queue& queue, boost::intrusive_ptr<Message> original)
{
boost::intrusive_ptr<Message> copy(new Message());
AMQFrame method((MessageTransferBody(ProtocolVersion(), EMPTY, 0, 0)));
AppendingHandler handler(copy);
handler.handle(method);
//To avoid modifying original headers, create new frame with
//cloned body:
AMQFrame header(*original->getFrames().getHeaders());
header.setBof(false);
header.setEof(!original->getFrames().getContentSize());//if there is any content then the header is not the end of the frameset
header.setBos(true);
header.setEos(true);
handler.handle(header);
original->sendContent(queue, handler, std::numeric_limits<int16_t>::max());
return copy;
}
Options* ReplicatingEventListener::getOptions()
{
return &options;
}
void ReplicatingEventListener::initialize(Plugin::Target& target)
{
Broker* broker = dynamic_cast<broker::Broker*>(&target);
if (broker) {
broker->addFinalizer(boost::bind(&ReplicatingEventListener::shutdown, this));
if (!options.exchange.empty()) {
if (!options.queue.empty()) {
QPID_LOG(warning, "Replication queue option ignored as replication exchange has been specified");
}
try {
exchange = broker->getExchanges().declare(options.exchange, options.exchangeType).first;
} catch (const UnknownExchangeTypeException&) {
QPID_LOG(error, "Replication disabled due to invalid type: " << options.exchangeType);
}
} else if (!options.queue.empty()) {
if (options.createQueue) {
queue = broker->getQueues().declare(options.queue).first;
} else {
queue = broker->getQueues().find(options.queue);
}
if (queue) {
queue->insertSequenceNumbers(REPLICATION_EVENT_SEQNO);
} else {
QPID_LOG(error, "Replication queue named '" << options.queue << "' does not exist; replication plugin disabled.");
}
}
if (queue || exchange) {
QueueEvents::EventListener callback = boost::bind(&ReplicatingEventListener::handle, this, _1);
broker->getQueueEvents().registerListener(options.name, callback);
QPID_LOG(info, "Registered replicating queue event listener");
}
}
}
void ReplicatingEventListener::earlyInitialize(Target&) {}
void ReplicatingEventListener::shutdown() { queue.reset(); exchange.reset(); }
ReplicatingEventListener::PluginOptions::PluginOptions() : Options("Queue Replication Options"),
exchangeType("direct"),
name("replicator"),
createQueue(false)
{
addOptions()
("replication-exchange-name", optValue(exchange, "EXCHANGE"), "Exchange to which events for other queues are routed")
("replication-exchange-type", optValue(exchangeType, "direct|topic etc"), "Type of exchange to use")
("replication-queue", optValue(queue, "QUEUE"), "Queue on which events for other queues are recorded")
("replication-listener-name", optValue(name, "NAME"), "name by which to register the replicating event listener")
("create-replication-queue", optValue(createQueue), "if set, the replication will be created if it does not exist");
}
static ReplicatingEventListener plugin;
}} // namespace qpid::replication
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