Add timestamp API and only poll map after change

api/server.js

@@ -7,6 +7,7 @@ const PORT = 3000;
 const HOST = '0.0.0.0';
 var map = '';
 var detection = '';
+var timestamp = '';
 var data = '';
 var capture = false;
 
@@ -29,6 +30,9 @@ app.get('/map', (req, res) => {
 app.get('/detection', (req, res) => {
   res.send(detection);
 });
+app.get('/timestamp', (req, res) => {
+  res.send(timestamp);
+});
 // read state of capture
 app.get('/capture', (req, res) => {
   res.send(capture);
@@ -77,3 +81,18 @@ const server_detection = net.createServer((socket)=>{
   })
 });
 server_detection.listen(3002);
+
+// tcp listener timestamp
+const server_timestamp = net.createServer((socket)=>{
+  socket.write("Hello From Server!")
+  socket.on("data",(msg)=>{
+    data = data + msg.toString();
+    console.log('EOF');
+    timestamp = data;
+    data = '';
+  });
+  socket.on("close",()=>{
+      console.log("Connection closed.");
+  })
+});
+server_timestamp.listen(4000);

config/config.yml

@@ -31,6 +31,7 @@ network:
     api: 3000
     map: 3001
     detect: 3002
+    timestamp: 4000
 
 save:
   iq: true

config/radar4.yml

@@ -31,6 +31,7 @@ network:
     api: 3000
     map: 3001
     detection: 3002
+    timestamp: 4000
 
 save:
   iq: true

html/plot.js

@@ -2,6 +2,7 @@ var timestamp = -1;
 var nRows = 3;
 var nCols = 3;
 var host = window.location.hostname;
+var timestamp = '';
 
 var isLocalHost = (host === "localhost" || host === "127.0.0.1" || host === "192.168.0.112");
 
@@ -12,6 +13,13 @@ if (isLocalHost) {
   urlMap = '//' + host + '/api/map?timestamp=' + Date.now();
 }
 
+var urlTimestamp = '';
+if (isLocalHost) {
+  urlTimestamp = '//' + host + ':3000/timestamp?timestamp=' + Date.now();
+} else {
+  urlTimestamp = '//' + host + '/api/timestamp?timestamp=' + Date.now();
+}
+
 var data = [
   {
     z: [[0, 0, 0], [0, 0, 0], [0, 0, 0]],
@@ -58,10 +66,16 @@ var config = {
 Plotly.newPlot('ddmap', data, layout, config);
 
 var intervalId = window.setInterval(function () {
-  var apiData = $.getJSON(urlMap, function () { })
+
+  // check if timestamp is updated
+  var timestampData = $.get(urlTimestamp, function () { })
 
     .done(function (data) {
-
+      if (timestamp != data) {
+        timestamp = data;
+        // get new map data
+        var apiData = $.getJSON(urlMap, function () { })
+          .done(function (data) {
             // case draw new plot
             if (data.nRows != nRows || data.nCols != nCols) {
               nRows = data.nRows;
@@ -139,4 +153,15 @@ var intervalId = window.setInterval(function () {
           .always(function () {
 
           });
+      }
+    })
+
+    .fail(function () {
+      console.log('API Fail');
+    })
+
+    .always(function () {
+
+    });
+
 }, 500);

src/blah2.cpp

@@ -93,22 +93,28 @@ int main(int argc, char **argv)
   fftw_plan_with_nthreads(4);
 
   // setup socket
-  uint16_t port_map, port_detection;
+  uint16_t port_map, port_detection, port_timestamp;
   std::string ip;
   tree["network"]["ports"]["map"] >> port_map;
   tree["network"]["ports"]["detection"] >> port_detection;
+  tree["network"]["ports"]["timestamp"] >> port_timestamp;
   tree["network"]["ip"] >> ip;
   asio::io_service io_service;
   asio::ip::tcp::socket socket_map(io_service);
   asio::ip::tcp::socket socket_detection(io_service);
+  asio::ip::tcp::socket socket_timestamp(io_service);
   asio::ip::tcp::endpoint endpoint_map;
   asio::ip::tcp::endpoint endpoint_detection;
+  asio::ip::tcp::endpoint endpoint_timestamp;
   endpoint_map = asio::ip::tcp::endpoint(
     asio::ip::address::from_string(ip), port_map);
   endpoint_detection = asio::ip::tcp::endpoint(
     asio::ip::address::from_string(ip), port_detection);
+  endpoint_timestamp = asio::ip::tcp::endpoint(
+    asio::ip::address::from_string(ip), port_timestamp);
   socket_map.connect(endpoint_map);
   socket_detection.connect(endpoint_detection);
+  socket_timestamp.connect(endpoint_timestamp);
   asio::error_code err;
   std::string subdata;
   uint32_t MTU = 1024;
@@ -228,6 +234,12 @@ int main(int argc, char **argv)
           auto t7 = std::chrono::high_resolution_clock::now();
           double delta_t7 = std::chrono::duration<double, std::milli>(t7-t0).count();
           std::cout << "CPI time (ms): " << delta_t7 << std::endl;
+
+          // output CPI timestamp for updating data
+          auto t0_duration = t0.time_since_epoch();
+          auto t0_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t0_duration).count();
+          std::string t0_string = std::to_string(t0_ms);
+          socket_timestamp.write_some(asio::buffer(t0_string, 100), err);
         }
       }
     });