Merge commit '09987d0f9d32e860f1391bb9c75b799501e2d141' as 'Subtrees/websocket'

Subtrees/websocket/examples/telemetry_server/telemetry_server.cpp

@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2012, Peter Thorson. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the WebSocket++ Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ */
+
+#include "../../src/websocketpp.hpp"
+
+#include <cstring>
+#include <set>
+
+#include <boost/functional.hpp>
+#include <boost/bind.hpp>
+
+using websocketpp::server;
+
+/// Thread body. Counts up indefinitely, one increment per second. After each
+/// it calls the handler back asking it to broadcast the new value. The handler
+/// callback returns whether or not the handler would like the telemetry thread
+/// to stop. If callback returns true the telemetry loop ands end the thread 
+/// exits.
+void generate_telemetry(boost::function<bool(const std::string&)> callback) {
+    size_t value = 0;
+    
+    for (;;) {        
+        // do some work
+        value++;
+        
+        // broadcast state
+        std::stringstream m;
+        m << value;
+        
+        if (callback(m.str())) {
+            break;
+        }
+        
+        // wait
+        boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
+    }
+}
+
+class telemetry_server_handler : public server::handler {
+public:
+    typedef telemetry_server_handler type;
+    typedef boost::shared_ptr<type> ptr;
+    
+    telemetry_server_handler() : m_done(false),m_value(0) {
+        boost::function<bool(const std::string&)> callback = boost::bind(&type::on_tick,this,_1);
+        
+        // start a thread that will generate telemetry independently and call
+        // this handler back when it has new data to send.
+        m_telemetry_thread.reset(new boost::thread(
+            boost::bind(
+                &generate_telemetry,
+                callback
+            )
+        ));
+    }
+    
+    // If the handler is going away set done to true and wait for the thread
+    // to exit.
+    ~telemetry_server_handler() {
+        {
+            boost::lock_guard<boost::mutex> guard(m_mutex);
+            m_done = true;
+        }
+        m_telemetry_thread->join();
+    }
+    
+    /// Function that we pass to the telemetry thread to broadcast the new 
+    /// state. It returns the global "are we done" value so we can control when
+    /// the thread stops running.
+    bool on_tick(const std::string& msg) {
+        boost::lock_guard<boost::mutex> guard(m_mutex);
+        
+        std::set<connection_ptr>::iterator it;
+        
+        for (it = m_connections.begin(); it != m_connections.end(); it++) {
+            (*it)->send(msg);
+        }
+        
+        return m_done;
+    }
+    
+    // register a new client
+    void on_open(connection_ptr con) {
+        boost::lock_guard<boost::mutex> guard(m_mutex);
+        m_connections.insert(con);
+    }
+    
+    // remove an exiting client
+    void on_close(connection_ptr con) {
+        boost::lock_guard<boost::mutex> guard(m_mutex);
+        m_connections.erase(con);
+    }
+private:
+    bool                                m_done;
+    size_t                              m_value;
+    std::set<connection_ptr>            m_connections;
+    
+    boost::mutex                        m_mutex;    // guards m_connections
+    boost::shared_ptr<boost::thread>    m_telemetry_thread;
+};
+
+int main(int argc, char* argv[]) {
+    unsigned short port = 9007;
+        
+    if (argc == 2) {
+        port = atoi(argv[1]);
+        
+        if (port == 0) {
+            std::cout << "Unable to parse port input " << argv[1] << std::endl;
+            return 1;
+        }
+    }
+    
+    try {       
+        server::handler::ptr handler(new telemetry_server_handler());
+        server endpoint(handler);
+                
+        endpoint.alog().unset_level(websocketpp::log::alevel::ALL);
+        endpoint.elog().unset_level(websocketpp::log::elevel::ALL);
+        
+        endpoint.alog().set_level(websocketpp::log::alevel::CONNECT);
+        endpoint.alog().set_level(websocketpp::log::alevel::DISCONNECT);
+        
+        endpoint.elog().set_level(websocketpp::log::elevel::RERROR);
+        endpoint.elog().set_level(websocketpp::log::elevel::FATAL);
+        
+        std::cout << "Starting WebSocket telemetry server on port " << port << std::endl;
+        endpoint.listen(port);
+    } catch (std::exception& e) {
+        std::cerr << "Exception: " << e.what() << std::endl;
+    }
+    
+    return 0;
+}