Add reporting/process.spawnAndMonitor() and chart.updateFromEventEmit…

…ter() to allow updating a chart from a child process.

Makefile

@@ -1,6 +1,6 @@
 .PHONY: clean templates compile
 PROCESS_TPL = scripts/process_tpl.js
-SOURCES = lib/header.js lib/config.js lib/util.js lib/stats.js lib/loop/loop.js lib/loop/multiloop.js lib/monitoring/collectors.js lib/monitoring/statslogger.js lib/monitoring/monitor.js lib/monitoring/monitorgroup.js lib/http.js lib/reporting/*.tpl.js lib/reporting/template.js lib/reporting/index.js lib/loadtesting.js lib/remote/endpoint.js lib/remote/endpointclient.js lib/remote/slave.js lib/remote/slaves.js lib/remote/slavenode.js lib/remote/cluster.js lib/remote/httphandler.js lib/remote/remotetesting.js
+SOURCES = lib/header.js lib/config.js lib/util.js lib/stats.js lib/loop/loop.js lib/loop/multiloop.js lib/monitoring/collectors.js lib/monitoring/statslogger.js lib/monitoring/monitor.js lib/monitoring/monitorgroup.js lib/http.js lib/reporting/*.tpl.js lib/reporting/template.js lib/reporting/index.js lib/reporting/process.js lib/loadtesting.js lib/remote/endpoint.js lib/remote/endpointclient.js lib/remote/slave.js lib/remote/slaves.js lib/remote/slavenode.js lib/remote/cluster.js lib/remote/httphandler.js lib/remote/remotetesting.js
 
 all: compile
 

lib/header.js

@@ -7,7 +7,8 @@ var util = require('util'),
     url = require('url'),
     fs = require('fs'),
     events = require('events'),
-    querystring = require('querystring');
+    querystring = require('querystring'),
+    child_process = require('child_process');
 
 var EventEmitter = events.EventEmitter;
 

lib/reporting/index.js

@@ -112,6 +112,22 @@ Chart.prototype = {
             row[col] = val;
         });
         self.rows.push(row);
+    },
+    /** Update chart using data from event emitter each time it emits an event. 'eventEmitter' should 
+    emit the given 'event' (defaults to 'data') with a single object. 'fields' are read from the object
+    and added to the chart. For example, a chart can track the output form a child process output using
+      
+      chart.updateFromEventEmitter(spawnAndMonitor('cmd', ['args'], /val: (.*)/, ['val']), ['val'])
+      
+    */
+    updateFromEventEmitter: function(eventEmitter, fields, event) {
+      eventEmitter.on(event || 'data', function(data) { 
+        var row = {};
+        fields.forEach(function(i) {
+          if (data[i] !== undefined) { row[i] = data[i]; }
+        });
+        this.put(row);
+      });
     }
 };
 

lib/reporting/process.js

@@ -0,0 +1,50 @@
+var BUILD_AS_SINGLE_FILE;
+if (!BUILD_AS_SINGLE_FILE) {
+var child_process = require('child_process');
+}
+
+/** Spawn a child process and extract data using a regex. Each line is compared to the regex. If a match
+is found, the groups are written to an object using the given field names, and the 'data' event is
+emitted.
+
+Returns a standard ChildProcess object, extended to emit('data', object).
+
+For example, if 'ls -al' prints:
+
+  drwxr-xr-x  22 user  staff     748 Feb  7 10:54 ./
+  drwxr-xr-x  23 user  staff     782 Feb  7 09:10 ../
+  -rw-r-----   1 user  staff      68 Jan 12 17:03 .gitignore
+
+then:
+
+  spawnAndMonitor(
+    /-(.)..(.)..(.)../, ['userReadable', 'groupReadable', 'worldReadable'],
+    'ls', ['-al']);
+
+will emit('data', {userReadable: 'r', groupReadable: 'r', worldReadable: '-'});
+*/
+var spawnAndMonitor = exports.spawnAndMonitor = function(regex, fields, spawnArguments) {
+  var buf = '', proc = child_process.spawn.apply(child_process, Array.prototype.slice.call(arguments, 2));
+  proc.stdout.on('data', function (data) {
+    buf += data.toString();
+
+    var lines = buf.split('\n');
+    buf = lines.pop();
+
+    lines.forEach(function(line) {
+      var vals = line.match(regex);
+      if (vals) {
+        if (fields) {
+          var obj = {};
+          for (var i = 1; i < vals.length; i++) {
+            obj[fields[i-1]] = vals[i];
+          }
+          proc.emit('data', obj);
+        } else {
+          proc.emit('data', vals);
+        }
+      }
+    });
+  });
+  return proc;
+};