scex tracer: add idle_mark support

1 files changed, 61 insertions, 30 deletions

diff --git a/gold/scex/tracer/index.js b/gold/scex/tracer/index.js
index e0c706e7..7ee6de1b 100644
--- a/gold/scex/tracer/index.js
+++ b/gold/scex/tracer/index.js
@@ -1,3 +1,10 @@
+#! /usr/bin/env node
+//
+// usage: [idle_mark=N] tracer
+//
+// Where the optional idle_mark tells the tracer to output idle marks every N
+// seconds.
+//
 var http = require('http');
 var slurp = require('./slurp');
 
@@ -7,9 +14,14 @@ var options = {
   path: '/api/t2'
 };
 
+var interval = 1000;
+var idle_mark = Number(process.env.idle_mark) * interval;
+
 var last_id = 0;
 var last_price = 0;
+var last_output = new Date(0);
 function t2 () {
+  var now = new Date()
   http.get(options, function(res) {
     slurp(res, function (data) {
       try {
@@ -17,42 +29,61 @@ function t2 () {
       } catch (exn) {
         return console.error('' + exn.stack + '');
       };
-      data
-        .sort(function (a, b) {
-          return a.id - b.id;
-        })
-        .forEach(function (x) {
-          if (x.id > last_id) {
-            last_id = x.id;
-
-            x.date = new Date(Number(x.date) * 1000);
-
-            var price = x.price.toString();
-            while (price.length < 'x.xxxxxxxx'.length) {
-              price += 0;
-            }
-            if (x.price > last_price) {
-              price = '' + price + ''
-            }
-            if (x.price < last_price) {
-              price = '' + price + ''
-            }
-            last_price = x.price;
-
-            var c = ({ buy: '', sell: '' })[x.type];
-            var m = '';
-            m += x.id
-            m += ' ' + JSON.parse(JSON.stringify(x.date))
+      data = data.sort(function (a, b) {
+        return a.id - b.id;
+      }).filter(function (x) {
+        return x.id > last_id;
+      });
+      if (data.length > 0) {
+        data.forEach(function (x) {
+          last_id = x.id;
+
+          x.date = new Date(Number(x.date) * 1000);
+
+          var price = render_price(x.price, last_price);
+          last_price = x.price;
+
+          var c = ({ buy: '', sell: '' })[x.type];
+          var m = '';
+          m += x.id
+          m += ' ' + JSON.parse(JSON.stringify(x.date))
+          m += ' ' + price
+          m += ' ' + c + x.amount + ''
+          console.log(m);
+          last_output = now;
+        });
+      } else {
+        if (idle_mark) {
+          if (now - last_output >= idle_mark) {
+            var price = render_price(last_price);
+            var m = last_id
+            m += ' ' + JSON.parse(JSON.stringify(now));
             m += ' ' + price
-            m += ' ' + c + x.amount + ''
             console.log(m);
-
+            last_output = now;
           };
-        });
+        };
+      };
     });
   }).on('error', function(e) {
     console.log("Got error: " + e.message);
   });
 };
 
-setInterval(t2, 1000);
+function render_price(price, last_price) {
+  var rendered_price = price.toString();
+  while (rendered_price.length < 'x.xxxxxxxx'.length) {
+    rendered_price += 0;
+  };
+  if (last_price) {
+    if (price > last_price) {
+      rendered_price = '' + rendered_price + ''
+    };
+    if (price < last_price) {
+      rendered_price = '' + rendered_price + ''
+    };
+  };
+  return rendered_price;
+};
+
+setInterval(t2, interval);