util: Importing scheduler, originally implemented in NFD
The scheduler uses monotonic clock whenever available.
This commit also includes an example to show how to work with the
scheduler.
Change-Id: I006bcc6afddd33caa8d1ec9575c0596234315411
diff --git a/examples/consumer-with-timer.cpp b/examples/consumer-with-timer.cpp
new file mode 100644
index 0000000..b8415d0
--- /dev/null
+++ b/examples/consumer-with-timer.cpp
@@ -0,0 +1,98 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/**
+ * Copyright (C) 2013 Regents of the University of California.
+ * @author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ * See COPYING for copyright and distribution information.
+ */
+
+// correct way to include NDN-CPP headers
+// #include <ndn-cpp-dev/face.hpp>
+#include "face.hpp"
+#include "util/scheduler.hpp"
+
+#include <stdexcept>
+
+#if NDN_CPP_HAVE_CXX11
+// In the std library, the placeholders are in a different namespace than boost.
+using namespace ndn::func_lib::placeholders;
+#endif
+
+void
+onData(ndn::Face &face,
+ const ndn::ptr_lib::shared_ptr<const ndn::Interest> &interest, const ndn::ptr_lib::shared_ptr<ndn::Data> &data)
+{
+ std::cout << "I: " << interest->toUri() << std::endl;
+ std::cout << "D: " << data->getName().toUri() << std::endl;
+}
+
+void
+onTimeout(ndn::Face &face,
+ const ndn::ptr_lib::shared_ptr<const ndn::Interest> &interest)
+{
+ std::cout << "Timeout" << std::endl;
+}
+
+void
+delayedInterest(ndn::Face &face)
+{
+ std::cout << "One more Interest, delayed by the scheduler" << std::endl;
+
+ ndn::Interest i(ndn::Name("/localhost/testApp/randomData"));
+ i.setScope(1);
+ i.setInterestLifetime(1000);
+ i.setMustBeFresh(true);
+
+ face.expressInterest(i,
+ ndn::bind(&onData, boost::ref(face), _1, _2),
+ ndn::bind(&onTimeout, boost::ref(face), _1));
+}
+
+void
+BlockPrinter(const ndn::Block &block, const std::string &indent="")
+{
+ std::cout << indent << block.type() << " (" << block.value_size() << ") [[";
+ std::cout.write(reinterpret_cast<const char *>(block.value()), block.value_size());
+ std::cout<< "]]" << std::endl;
+
+ for(ndn::Block::element_const_iterator i = block.getAll().begin();
+ i != block.getAll().end();
+ ++i)
+ {
+ BlockPrinter(*i, indent+" ");
+ }
+}
+
+int main()
+{
+ try {
+ // Explicitly create io_service object, which can be shared between
+ // Face and Scheduler
+ ndn::shared_ptr<boost::asio::io_service> io =
+ ndn::make_shared<boost::asio::io_service>();
+
+ ndn::Interest i(ndn::Name("/localhost/testApp/randomData"));
+ i.setScope(1);
+ i.setInterestLifetime(1000);
+ i.setMustBeFresh(true);
+
+ ndn::Face face(io);
+ face.expressInterest(i,
+ ndn::bind(&onData, boost::ref(face), _1, _2),
+ ndn::bind(&onTimeout, boost::ref(face), _1));
+
+
+ ndn::Scheduler scheduler(*io);
+ scheduler.scheduleEvent(ndn::time::seconds(2),
+ ndn::bind(&delayedInterest, boost::ref(face)));
+
+ io->run();
+
+ // Alternatively, a helper face.processEvents() also can be called
+ // processEvents will block until the requested data received or timeout occurs
+ // face.processEvents();
+ }
+ catch(std::exception &e) {
+ std::cerr << "ERROR: " << e.what() << std::endl;
+ }
+ return 0;
+}