2 files changed, 127 insertions, 0 deletions

diff --git a/gold/scex/tracer/index.js b/gold/scex/tracer/index.js
new file mode 100644
index 00000000..7ee6de1b
--- /dev/null
+++ b/gold/scex/tracer/index.js
@@ -0,0 +1,89 @@
+#! /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');
+
+var options = {
+  host: 'scexchange.bitparking.com',
+  port: 8080,
+  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 {
+        data = JSON.parse(data);
+      } catch (exn) {
+        return console.error('' + exn.stack + '');
+      };
+      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
+            console.log(m);
+            last_output = now;
+          };
+        };
+      };
+    });
+  }).on('error', function(e) {
+    console.log("Got error: " + e.message);
+  });
+};
+
+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);
diff --git a/gold/scex/tracer/slurp.js b/gold/scex/tracer/slurp.js
new file mode 100644
index 00000000..70319743
--- /dev/null
+++ b/gold/scex/tracer/slurp.js
@@ -0,0 +1,38 @@
+module.exports = (function () {
+
+  function join_buffers (buffers, length) {
+    var buffer = new Buffer(length);
+    var targetStart = 0;
+    buffers.forEach(function (x) {
+      x.copy(buffer, targetStart);
+      targetStart += x.length;
+    });
+    return buffer;
+  };
+
+  function finish_it (req, buffers, length, callback) {
+    req.content = join_buffers(buffers, length);
+    return callback(req.content);
+  };
+
+  function nop () {};
+
+  return function (req, callback) {
+    if (req.hasOwnProperty('content')) {
+      return callback(req.content);
+    };
+    var content = [];
+    var length = 0;
+    var end_handler = finish_it;
+    req.on('data', function (data) {
+      content.push(data);
+      length += data.length;
+    });
+    [ 'end', 'close' ].forEach(function (event) {
+      req.on(event, function () {
+        finish_it(req, content, length, callback);
+        end_handler = nop;
+      });
+    });
+  };
+})();