1 files changed, 228 insertions, 0 deletions
diff --git a/qpid/cpp/src/qpid/ha/Membership.cpp b/qpid/cpp/src/qpid/ha/Membership.cpp
new file mode 100644
index 0000000000..92a0b7db70
--- /dev/null
+++ b/qpid/cpp/src/qpid/ha/Membership.cpp
@@ -0,0 +1,228 @@
+/*
+ *
+ * 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 "ConnectionObserver.h"
+#include "HaBroker.h"
+#include "Membership.h"
+#include "qpid/broker/Broker.h"
+#include "qpid/framing/FieldTable.h"
+#include "qpid/management/ManagementAgent.h"
+#include "qpid/types/Variant.h"
+#include "qmf/org/apache/qpid/ha/EventMembersUpdate.h"
+#include "qmf/org/apache/qpid/ha/HaBroker.h"
+#include <boost/bind.hpp>
+#include <iostream>
+#include <iterator>
+
+namespace qpid {
+namespace ha {
+
+namespace _qmf = ::qmf::org::apache::qpid::ha;
+
+using sys::Mutex;
+using types::Variant;
+
+Membership::Membership(const BrokerInfo& info, HaBroker& b)
+    : haBroker(b), self(info.getSystemId())
+{
+    brokers[self] = info;
+    setPrefix();
+    oldStatus = info.getStatus();
+}
+
+void Membership::setPrefix() {
+    haBroker.logPrefix = Msg() << shortStr(brokers[self].getSystemId())
+                               << "(" << printable(brokers[self].getStatus()) << ") ";
+}
+void Membership::clear() {
+    Mutex::ScopedLock l(lock);
+    BrokerInfo me = brokers[self];
+    brokers.clear();
+    brokers[self] = me;
+}
+
+void Membership::add(const BrokerInfo& b) {
+    Mutex::ScopedLock l(lock);
+    assert(b.getSystemId() != self);
+    brokers[b.getSystemId()] = b;
+    update(true, l);
+}
+
+
+void Membership::remove(const types::Uuid& id) {
+    Mutex::ScopedLock l(lock);
+    if (id == self) return;     // Never remove myself
+    BrokerInfo::Map::iterator i = brokers.find(id);
+    if (i != brokers.end()) {
+        brokers.erase(i);
+        update(true, l);
+    }
+}
+
+bool Membership::contains(const types::Uuid& id) {
+    Mutex::ScopedLock l(lock);
+    return brokers.find(id) != brokers.end();
+}
+
+void Membership::assign(const types::Variant::List& list) {
+    Mutex::ScopedLock l(lock);
+    clear();
+    for (types::Variant::List::const_iterator i = list.begin(); i != list.end(); ++i) {
+        BrokerInfo b(i->asMap());
+        brokers[b.getSystemId()] = b;
+    }
+    update(true, l);
+}
+
+types::Variant::List Membership::asList() const {
+    Mutex::ScopedLock l(lock);
+    return asList(l);
+}
+
+types::Variant::List Membership::asList(sys::Mutex::ScopedLock&) const {
+    types::Variant::List list;
+    for (BrokerInfo::Map::const_iterator i = brokers.begin(); i != brokers.end(); ++i)
+        list.push_back(i->second.asMap());
+    return list;
+}
+
+BrokerInfo::Set Membership::otherBackups() const {
+    Mutex::ScopedLock l(lock);
+    BrokerInfo::Set result;
+    for (BrokerInfo::Map::const_iterator i = brokers.begin(); i != brokers.end(); ++i)
+        if (i->second.getStatus() == READY && i->second.getSystemId() != self)
+            result.insert(i->second);
+    return result;
+}
+
+BrokerInfo::Set Membership::getBrokers() const {
+    Mutex::ScopedLock l(lock);
+    BrokerInfo::Set result;
+    transform(brokers.begin(), brokers.end(), inserter(result, result.begin()),
+              boost::bind(&BrokerInfo::Map::value_type::second, _1));
+    return result;
+}
+
+bool Membership::get(const types::Uuid& id, BrokerInfo& result) const {
+    Mutex::ScopedLock l(lock);
+    BrokerInfo::Map::const_iterator i = brokers.find(id);
+    if (i == brokers.end()) return false;
+    result = i->second;
+    return true;
+}
+
+namespace {
+bool checkTransition(BrokerStatus from, BrokerStatus to) {
+    // Legal state transitions. Initial state is JOINING, ACTIVE is terminal.
+    static const BrokerStatus TRANSITIONS[][2] = {
+        { STANDALONE, JOINING }, // Initialization of backup broker
+        { JOINING, CATCHUP },    // Connected to primary
+        { JOINING, RECOVERING }, // Chosen as initial primary.
+        { CATCHUP, READY },      // Caught up all queues, ready to take over.
+        { READY, RECOVERING },   // Chosen as new primary
+        { READY, CATCHUP },      // Timed out failing over, demoted to catch-up.
+        { RECOVERING, ACTIVE }   // All expected backups are ready
+    };
+    static const size_t N = sizeof(TRANSITIONS)/sizeof(TRANSITIONS[0]);
+    for (size_t i = 0; i < N; ++i) {
+        if (TRANSITIONS[i][0] == from && TRANSITIONS[i][1] == to)
+            return true;
+    }
+    return false;
+}
+} // namespace
+
+void Membership::update(bool log, Mutex::ScopedLock& l) {
+    // Update managment and send update event.
+    BrokerStatus newStatus = getStatus(l);
+    Variant::List brokerList = asList(l);
+    if (mgmtObject) {
+        mgmtObject->set_status(printable(newStatus).str());
+        mgmtObject->set_members(brokerList);
+    }
+    haBroker.getBroker().getManagementAgent()->raiseEvent(
+        _qmf::EventMembersUpdate(brokerList));
+
+    // Update link client properties
+    framing::FieldTable linkProperties = haBroker.getBroker().getLinkClientProperties();
+    if (isBackup(newStatus)) {
+        // Set backup tag on outgoing link properties.
+        linkProperties.setTable(
+            ConnectionObserver::BACKUP_TAG, brokers[types::Uuid(self)].asFieldTable());
+        haBroker.getBroker().setLinkClientProperties(linkProperties);
+    } else {
+        // Remove backup tag property from outgoing link properties.
+        linkProperties.erase(ConnectionObserver::BACKUP_TAG);
+        haBroker.getBroker().setLinkClientProperties(linkProperties);
+    }
+
+    // Check status transitions
+    if (oldStatus != newStatus) {
+        QPID_LOG(info, haBroker.logPrefix << "Status change: "
+                 << printable(oldStatus) << " -> " << printable(newStatus));
+        if (!checkTransition(oldStatus, newStatus)) {
+            haBroker.shutdown(QPID_MSG("Illegal state transition: " << printable(oldStatus)
+                                       << " -> " << printable(newStatus)));
+        }
+        oldStatus = newStatus;
+        setPrefix();
+        if (newStatus == READY) QPID_LOG(notice, haBroker.logPrefix << "Backup is ready");
+    }
+    if (log) QPID_LOG(info, haBroker.logPrefix << "Membership update: " <<  brokers);
+}
+
+void Membership::setMgmtObject(boost::shared_ptr<_qmf::HaBroker> mo) {
+    Mutex::ScopedLock l(lock);
+    mgmtObject = mo;
+    update(false, l);
+}
+
+
+void Membership::setStatus(BrokerStatus newStatus) {
+    Mutex::ScopedLock l(lock);
+    brokers[self].setStatus(newStatus);
+    update(false, l);
+}
+
+BrokerStatus Membership::getStatus() const  {
+    Mutex::ScopedLock l(lock);
+    return getStatus(l);
+}
+
+BrokerStatus Membership::getStatus(sys::Mutex::ScopedLock&) const  {
+    BrokerInfo::Map::const_iterator i = brokers.find(self);
+    assert(i != brokers.end());
+    return i->second.getStatus();
+}
+
+BrokerInfo Membership::getSelf() const  {
+    Mutex::ScopedLock l(lock);
+    BrokerInfo::Map::const_iterator i = brokers.find(self);
+    assert(i != brokers.end());
+    return i->second;
+}
+
+void Membership::setSelfAddress(const Address& a) {
+    Mutex::ScopedLock l(lock);
+    brokers[self].setAddress(a);
+    update(false, l);
+}
+
+}} // namespace qpid::ha