Merge branch 'beta' into mergemaster

# Conflicts:
#	src/main.cpp

src/amqp/amqpsender.h

@@ -0,0 +1,115 @@
+// Copyright (c) 2017 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef ZCASH_AMQP_AMQPSENDER_H
+#define ZCASH_AMQP_AMQPSENDER_H
+
+#include "amqpconfig.h"
+
+#include <deque>
+#include <memory>
+#include <future>
+#include <iostream>
+
+class AMQPSender : public proton::messaging_handler {
+  private:
+    std::deque<proton::message> messages_; 
+    proton::url url_;
+    proton::connection conn_;
+    proton::sender sender_;
+    std::mutex lock_;
+    std::atomic<bool> terminated_ = {false};
+
+  public:
+
+    AMQPSender(const std::string& url) : url_(url) {}
+
+    // Callback to initialize the container when run() is invoked
+    void on_container_start(proton::container& c) override {
+        proton::duration t(10000);   // milliseconds
+        proton::connection_options opts = proton::connection_options().idle_timeout(t);
+        conn_ = c.connect(url_, opts);
+        sender_ = conn_.open_sender(url_.path());
+    }
+
+    // Remote end signals when the local end can send (i.e. has credit) 
+    void on_sendable(proton::sender &s) override {
+        dispatch();
+    }
+
+    // Publish message by adding to queue and trying to dispatch it
+    void publish(const proton::message &m) {
+        add_message(m);
+        dispatch();
+    }
+
+    // Add message to queue
+    void add_message(const proton::message &m) {
+        std::lock_guard<std::mutex> guard(lock_);
+        messages_.push_back(m);
+    }
+
+    // Send messages in queue
+    void dispatch() {
+        std::lock_guard<std::mutex> guard(lock_);
+
+        if (isTerminated()) {
+            throw std::runtime_error("amqp connection was terminated");
+        }
+
+        if (!conn_.active()) {
+            throw std::runtime_error("amqp connection is not active");
+        }
+
+        while (messages_.size() > 0) {
+            if (sender_.credit()) {
+                const proton::message& m = messages_.front();
+                sender_.send(m);
+                messages_.pop_front();
+            } else {
+                break;
+            }
+        }
+    }
+
+    // Close connection to remote end.  Container event-loop, by default, will auto-stop.
+    void terminate() {
+        std::lock_guard<std::mutex> guard(lock_);
+        conn_.close();
+        terminated_.store(true);
+    }
+
+    bool isTerminated() const {
+        return terminated_.load();
+    }
+
+    void on_transport_error(proton::transport &t) override {
+        t.connection().close();
+        throw t.error();
+    }
+
+    void on_connection_error(proton::connection &c) override {
+        c.close();
+        throw c.error();
+    }
+
+    void on_session_error(proton::session &s) override {
+        s.connection().close();
+        throw s.error();
+    }
+
+    void on_receiver_error(proton::receiver &r) override {
+        r.connection().close();
+        throw r.error();
+    }
+
+    void on_sender_error(proton::sender &s) override {
+        s.connection().close();
+        throw s.error();
+    }
+
+};
+
+
+#endif //ZCASH_AMQP_AMQPSENDER_H