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/*
*
* Copyright (c) 2006 The Apache Software Foundation
*
* Licensed 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 "Cluster.h"
#include "qpid/framing/AMQFrame.h"
#include "qpid/framing/ClusterNotifyBody.h"
#include "qpid/log/Statement.h"
#include <boost/bind.hpp>
#include <algorithm>
#include <iterator>
#include <map>
namespace qpid {
namespace cluster {
using namespace qpid::framing;
using namespace qpid::sys;
using namespace std;
ostream& operator <<(ostream& out, const Cluster& cluster) {
return out << "cluster[" << cluster.name.str() << " " << cluster.self << "]";
}
ostream& operator<<(ostream& out, const Cluster::MemberMap::value_type& m) {
return out << m.first << "=" << m.second->url;
}
ostream& operator <<(ostream& out, const Cluster::MemberMap& members) {
ostream_iterator<Cluster::MemberMap::value_type> o(out, " ");
copy(members.begin(), members.end(), o);
return out;
}
namespace {
/** We mark the high bit of a frame's channel number to know if it's
* an incoming or outgoing frame when frames arrive via multicast.
*/
bool isOutgoing(AMQFrame& frame) { return frame.channel&CHANNEL_HIGH_BIT; }
bool isIncoming(AMQFrame& frame) { return !isOutgoing(frame); }
void markOutgoing(AMQFrame& frame) { frame.channel |= CHANNEL_HIGH_BIT; }
void markIncoming(AMQFrame&) { /*noop*/ }
void unMark(AMQFrame& frame) { frame.channel &= ~CHANNEL_HIGH_BIT; }
}
struct Cluster::IncomingHandler : public FrameHandler {
IncomingHandler(Cluster& c) : cluster(c) {}
void handle(AMQFrame& frame) {
markIncoming(frame);
cluster.mcast(frame);
}
Cluster& cluster;
};
struct Cluster::OutgoingHandler : public FrameHandler {
OutgoingHandler(Cluster& c) : cluster(c) {}
void handle(AMQFrame& frame) {
markOutgoing(frame);
cluster.mcast(frame);
}
Cluster& cluster;
};
// TODO aconway 2007-06-28: Right now everything is backed up via
// multicast. When we have point-to-point backups the
// Incoming/Outgoing handlers must determine where each frame should
// be sent: to multicast or only to specific backup(s) via AMQP.
Cluster::Cluster(const std::string& name_, const std::string& url_) :
cpg(new Cpg(*this)),
name(name_),
url(url_),
self(cpg->getLocalNoideId(), getpid()),
toChains(new IncomingHandler(*this), new OutgoingHandler(*this))
{
QPID_LOG(trace, *this << " Joining cluster.");
cpg->join(name);
notify();
dispatcher=Thread(*this);
// Wait till we show up in the cluster map.
{
Mutex::ScopedLock l(lock);
while (empty())
lock.wait();
}
}
Cluster::~Cluster() {
QPID_LOG(trace, *this << " Leaving cluster.");
try {
cpg->leave(name);
cpg.reset();
dispatcher.join();
}
catch (const std::exception& e) {
QPID_LOG(error, "Exception leaving cluster " << *this << ": "
<< e.what());
}
}
void Cluster::mcast(AMQFrame& frame) {
QPID_LOG(trace, *this << " SEND: " << frame);
Buffer buf(frame.size());
frame.encode(buf);
buf.flip();
iovec iov = { buf.start(), frame.size() };
cpg->mcast(name, &iov, 1);
}
void Cluster::notify() {
// TODO aconway 2007-06-25: Use proxy here.
ProtocolVersion version;
AMQFrame frame(version, 0,
make_shared_ptr(new ClusterNotifyBody(version, url)));
mcast(frame);
}
size_t Cluster::size() const {
Mutex::ScopedLock l(lock);
return members.size();
}
void Cluster::setFromChains(const framing::FrameHandler::Chains& chains) {
Mutex::ScopedLock l(lock);
fromChains = chains;
}
Cluster::MemberList Cluster::getMembers() const {
Mutex::ScopedLock l(lock);
MemberList result(members.size());
std::transform(members.begin(), members.end(), result.begin(),
boost::bind(&MemberMap::value_type::second, _1));
return result;
}
void Cluster::deliver(
cpg_handle_t /*handle*/,
struct cpg_name* /* group */,
uint32_t nodeid,
uint32_t pid,
void* msg,
int msg_len)
{
Id from(nodeid, pid);
Buffer buf(static_cast<char*>(msg), msg_len);
AMQFrame frame;
frame.decode(buf);
QPID_LOG(trace, *this << " RECV: " << frame << " from: " << from);
if (!handleClusterFrame(from, frame)) {
FrameHandler::Chain chain = isIncoming(frame) ? fromChains.in : fromChains.out;
unMark(frame);
if (chain)
chain->handle(frame);
}
}
bool Cluster::wait(boost::function<bool(const Cluster&)> predicate,
Duration timeout) const
{
AbsTime deadline(now(), timeout);
Mutex::ScopedLock l(lock);
while (!predicate(*this) && lock.wait(deadline))
;
return (predicate(*this));
}
bool Cluster::handleClusterFrame(Id from, AMQFrame& frame) {
// TODO aconway 2007-06-20: use visitor pattern here.
ClusterNotifyBody* notifyIn=
dynamic_cast<ClusterNotifyBody*>(frame.getBody().get());
if (notifyIn) {
MemberList list;
{
Mutex::ScopedLock l(lock);
if (!members[from])
members[from].reset(new Member(url));
else
members[from]->url = notifyIn->getUrl();
QPID_LOG(trace, *this << ": member update: " << members);
lock.notifyAll();
}
return true;
}
return false;
}
void Cluster::configChange(
cpg_handle_t /*handle*/,
struct cpg_name */*group*/,
struct cpg_address */*current*/, int /*nCurrent*/,
struct cpg_address *left, int nLeft,
struct cpg_address *joined, int nJoined)
{
bool newMembers=false;
MemberList updated;
{
Mutex::ScopedLock l(lock);
if (nLeft) {
for (int i = 0; i < nLeft; ++i)
members.erase(Id(left[i]));
QPID_LOG(trace, *this << ": members left: " << members);
lock.notifyAll();
}
newMembers = nJoined > 1 || (nJoined==1 && Id(joined[0]) != self);
// We don't record members joining here, we record them when
// we get their ClusterNotify message.
}
if (newMembers)
notify();
}
void Cluster::run() {
cpg->dispatchBlocking();
}
}} // namespace qpid::cluster
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