Merge lp:~saysjonathan/graphite/rangeseries into lp:~graphite-dev/graphite/main

[saysjonathan]

[FEATURE] Adds a new Graph Data Function: rangeOfSeries. Distills down a set of inputs into the range of the series, e.g., [0, 1, 2, 3] = 3, and [4, 5, 6] = 2

[Michael Leinartas (mleinartas)]

Looks great, good idea and thanks for the good docstring

review: Approve

=== modified file 'webapp/content/js/composer_widgets.js'
--- webapp/content/js/composer_widgets.js	2011-12-05 08:30:48 +0000
+++ webapp/content/js/composer_widgets.js	2012-02-09 00:23:46 +0000
@@ -884,7 +884,8 @@
         {text: 'Average', handler: applyFuncToAll('averageSeries')},
         {text: 'Min Values', handler: applyFuncToAll('minSeries')},
         {text: 'Max Values', handler: applyFuncToAll('maxSeries')},
-        {text: 'Group', handler: applyFuncToAll('group')}
+        {text: 'Group', handler: applyFuncToAll('group')},
+        {text: 'Range', handler: this.applyFuncToAll('rangeOfSeries')}
       ]
     }, {
       text: 'Transform',

=== modified file 'webapp/graphite/render/functions.py'
--- webapp/graphite/render/functions.py	2012-02-08 05:40:42 +0000
+++ webapp/graphite/render/functions.py	2012-02-09 00:23:46 +0000
@@ -55,6 +55,10 @@
   if a is None or b is None: return None
   return float(a) * float(b)
 
+def safeSubtract(a,b):
+    if a is None or b is None: return None
+    return float(a) - float(b)
+
 def safeLast(values):
   for v in reversed(values):
     if v is not None: return v
@@ -269,6 +273,25 @@
   series.pathExpression = name
   return [series]
 
+def rangeOfSeries(requestContext, *seriesLists):
+    """
+    Takes a wildcard seriesList.
+    Distills down a set of inputs into the range of the series
+
+    Example:
+
+    .. code-block:: none
+    
+        &target=rangeOfSeries(Server*.connections.total)
+
+    """
+    (seriesList,start,end,step) = normalize(seriesLists)
+    name = "rangeOfSeries(%s)" % ','.join(set([s.pathExpression for s in seriesList]))
+    values = ( safeSubtract(max(row), min(row)) for row in izip(*seriesList) )
+    series = TimeSeries(name,start,end,step,values)
+    series.pathExpression = name
+    return [series]
+
 def keepLastValue(requestContext, seriesList):
   """
   Takes one metric or a wildcard seriesList.
@@ -2060,6 +2083,7 @@
   'averageSeriesWithWildcards': averageSeriesWithWildcards,
   'minSeries' : minSeries,
   'maxSeries' : maxSeries,
+  'rangeOfSeries': rangeOfSeries,
 
   # Transform functions
   'scale' : scale,