Add ZeroMQ support. Notify blocks and transactions via ZeroMQ

Continues Johnathan Corgan's work.
Publishing multipart messages

Bugfix: Add missing zmq header includes

Bugfix: Adjust build system to link ZeroMQ code for Qt binaries

src/zmq/zmqnotificationinterface.cpp

@@ -0,0 +1,155 @@
+// Copyright (c) 2015 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "zmqnotificationinterface.h"
+#include "zmqpublishnotifier.h"
+
+#include "version.h"
+#include "main.h"
+#include "streams.h"
+#include "util.h"
+
+void zmqError(const char *str)
+{
+    LogPrint("zmq", "Error: %s, errno=%s\n", str, zmq_strerror(errno));
+}
+
+CZMQNotificationInterface::CZMQNotificationInterface() : pcontext(NULL)
+{
+}
+
+CZMQNotificationInterface::~CZMQNotificationInterface()
+{
+    // ensure Shutdown if Initialize is called
+    assert(!pcontext);
+
+    for (std::list<CZMQAbstractNotifier*>::iterator i=notifiers.begin(); i!=notifiers.end(); ++i)
+    {
+        delete *i;
+    }
+}
+
+CZMQNotificationInterface* CZMQNotificationInterface::CreateWithArguments(const std::map<std::string, std::string> &args)
+{
+    CZMQNotificationInterface* notificationInterface = NULL;
+    std::map<std::string, CZMQNotifierFactory> factories;
+    std::list<CZMQAbstractNotifier*> notifiers;
+
+    factories["pubhashblock"] = CZMQAbstractNotifier::Create<CZMQPublishHashBlockNotifier>;
+    factories["pubhashtx"] = CZMQAbstractNotifier::Create<CZMQPublishHashTransactionNotifier>;
+    factories["pubrawblock"] = CZMQAbstractNotifier::Create<CZMQPublishRawBlockNotifier>;
+    factories["pubrawtx"] = CZMQAbstractNotifier::Create<CZMQPublishRawTransactionNotifier>;
+
+    for (std::map<std::string, CZMQNotifierFactory>::const_iterator i=factories.begin(); i!=factories.end(); ++i)
+    {
+        std::map<std::string, std::string>::const_iterator j = args.find("-zmq" + i->first);
+        if (j!=args.end())
+        {
+            CZMQNotifierFactory factory = i->second;
+            std::string address = j->second;
+            CZMQAbstractNotifier *notifier = factory();
+            notifier->SetType(i->first);
+            notifier->SetAddress(address);
+            notifiers.push_back(notifier);
+        }
+    }
+
+    if (!notifiers.empty())
+    {
+        notificationInterface = new CZMQNotificationInterface();
+        notificationInterface->notifiers = notifiers;
+    }
+
+    return notificationInterface;
+}
+
+// Called at startup to conditionally set up ZMQ socket(s)
+bool CZMQNotificationInterface::Initialize()
+{
+    LogPrint("zmq", "Initialize notification interface\n");
+    assert(!pcontext);
+
+    pcontext = zmq_init(1);
+
+    if (!pcontext)
+    {
+        zmqError("Unable to initialize context");
+        return false;
+    }
+
+    std::list<CZMQAbstractNotifier*>::iterator i=notifiers.begin();
+    for (; i!=notifiers.end(); ++i)
+    {
+        CZMQAbstractNotifier *notifier = *i;
+        if (notifier->Initialize(pcontext))
+        {
+            LogPrint("zmq", "  Notifier %s ready (address = %s)\n", notifier->GetType(), notifier->GetAddress());
+        }
+        else
+        {
+            LogPrint("zmq", "  Notifier %s failed (address = %s)\n", notifier->GetType(), notifier->GetAddress());
+            break;
+        }
+    }
+
+    if (i!=notifiers.end())
+    {
+        Shutdown();
+        return false;
+    }
+
+    return false;
+}
+
+// Called during shutdown sequence
+void CZMQNotificationInterface::Shutdown()
+{
+    LogPrint("zmq", "Shutdown notification interface\n");
+    if (pcontext)
+    {
+        for (std::list<CZMQAbstractNotifier*>::iterator i=notifiers.begin(); i!=notifiers.end(); ++i)
+        {
+            CZMQAbstractNotifier *notifier = *i;
+            LogPrint("zmq", "   Shutdown notifier %s at %s\n", notifier->GetType(), notifier->GetAddress());
+            notifier->Shutdown();
+        }
+        zmq_ctx_destroy(pcontext);
+
+        pcontext = 0;
+    }
+}
+
+void CZMQNotificationInterface::UpdatedBlockTip(const uint256 &hash)
+{
+    for (std::list<CZMQAbstractNotifier*>::iterator i = notifiers.begin(); i!=notifiers.end(); )
+    {
+        CZMQAbstractNotifier *notifier = *i;
+        if (notifier->NotifyBlock(hash))
+        {
+            i++;
+        }
+        else
+        {
+            notifier->Shutdown();
+            i = notifiers.erase(i);
+        }
+    }
+}
+
+void CZMQNotificationInterface::SyncTransaction(const CTransaction &tx, const CBlock *pblock)
+{
+    for (std::list<CZMQAbstractNotifier*>::iterator i = notifiers.begin(); i!=notifiers.end(); )
+    {
+        CZMQAbstractNotifier *notifier = *i;
+        if (notifier->NotifyTransaction(tx))
+        {
+            i++;
+        }
+        else
+        {
+            notifier->Shutdown();
+            i = notifiers.erase(i);
+        }
+    }
+}