From e472352274a5c9dc644da963392566de053c0083 Mon Sep 17 00:00:00 2001
From: Varun Patil <varunpatil@ucla.edu>
Date: Mon, 6 Jan 2025 03:30:37 +0000
Subject: [PATCH] example: add core for interop test

---
 examples/core.cpp | 104 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 examples/core.cpp

diff --git a/examples/core.cpp b/examples/core.cpp
new file mode 100644
index 0000000..9735409
--- /dev/null
+++ b/examples/core.cpp
@@ -0,0 +1,104 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2012-2025 University of California, Los Angeles
+ *
+ * This file is part of ndn-svs, synchronization library for distributed realtime
+ * applications for NDN.
+ *
+ * ndn-svs library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, in version 2.1 of the License.
+ *
+ * ndn-svs library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ */
+
+#include <iostream>
+#include <string>
+#include <string_view>
+#include <thread>
+#include <vector>
+
+#include <ndn-svs/svsync.hpp>
+
+struct Options
+{
+  std::string prefix;
+  std::string m_id;
+};
+
+class Program
+{
+public:
+  Program(const Options& options)
+    : m_options(options)
+  {
+    // This is a usage example of the low level SvSyncCore API.
+
+    // Create the SVSyncCore instance
+    m_svs = std::make_shared<ndn::svs::SVSyncCore>(
+      face,                                    // Shared NDN face
+      ndn::Name(m_options.prefix),             // Sync prefix, common for all nodes in the group
+      std::bind(&Program::onUpdate, this, _1), // Callback on learning new sequence numbers from SVS
+      ndn::svs::SecurityOptions::DEFAULT,      // Security configuration
+      ndn::Name(m_options.m_id)                // Unique prefix for this node
+    );
+
+    std::cout << "SVS client starting: " << m_options.m_id << std::endl;
+  }
+
+  void run()
+  {
+    // Begin processing face events in a separate thread.
+    std::thread svsThread([this] { face.processEvents(); });
+
+    // Increment our sequence number every 3 seconds
+    while (true) {
+      auto seq = m_svs->getSeqNo() + 1;
+      m_svs->updateSeqNo(seq);
+      std::cout << "Published sequence number: " << m_options.m_id << "=" << seq << std::endl;
+      std::this_thread::sleep_for(std::chrono::seconds(3));
+    }
+
+    // Wait for the SVSync thread to finish on exit.
+    svsThread.join();
+  }
+
+protected:
+  /**
+   * Callback on receving a new State Vector from another node
+   */
+  void onUpdate(const std::vector<ndn::svs::MissingDataInfo>& v)
+  {
+    for (size_t i = 0; i < v.size(); i++) {
+      for (ndn::svs::SeqNo s = v[i].low; s <= v[i].high; ++s) {
+        std::cout << "Received update: " << v[i].nodeId << "=" << s << std::endl;
+      }
+    }
+  }
+
+public:
+  const Options m_options;
+  ndn::Face face;
+  std::shared_ptr<ndn::svs::SVSyncCore> m_svs;
+  ndn::KeyChain m_keyChain;
+};
+
+int
+main(int argc, char** argv)
+{
+  if (argc != 2) {
+    std::cerr << "Usage: " << argv[0] << " <prefix>" << std::endl;
+    return 1;
+  }
+
+  Options opt;
+  opt.prefix = "/ndn/svs";
+  opt.m_id = argv[1];
+
+  Program program(opt);
+  program.run();
+
+  return 0;
+}