Changeset 12942 in vbox for trunk/src/libs/xpcom18a4/python

Timestamp:

Oct 2, 2008 2:53:11 PM (16 years ago)

Author:

vboxsync

Message:

PerfAPI: Fixed the problem with passing null/empty arrays to PerfAPI methods.
Enabled attributes of type IUnknown in SOAP, JAX-WS, WSDL, CPP and Python style sheets.
Added PerfCollector python class to shellcommon.py to provide more 'pythonic' way to access metric data.
Added the reference to shellcommon.py to IDL docs as an example of PerfAPI usage in python.

File:

• trunk/src/libs/xpcom18a4/python/sample/shellcommon.py (modified) (8 diffs)

trunk/src/libs/xpcom18a4/python/sample/shellcommon.py

@@ -2 +2 @@
 import sys
 import pdb
+
+class PerfCollector:
+    """ This class provides a wrapper over IPerformanceCollector in order to
+    get more 'pythonic' interface.
+
+    To begin collection of metrics use setup() method.
+
+    To get collected data use query() method.
+
+    It is possible to disable metric collection without changing collection
+    parameters with disable() method. The enable() method resumes metric
+    collection.
+    """
+
+    def __init__(self, vb):
+        """ Initializes the instance.
+        
+        Pass an instance of IVirtualBox as parameter.
+        """
+        self.collector = vb.performanceCollector 
+
+    def _update_metric_params(self):
+        metrics = self.collector.getMetrics(['*'], None)
+        self.metrics = {}
+        for m in metrics:
+            self.metrics[str(m.object) + "/" + str(m.metricName)] = m
+
+    def setup(self, names, objects, period, nsamples):
+        """ Discards all previously collected values for the specified
+        metrics, sets the period of collection and the number of retained
+        samples, enables collection.
+        """
+        self.collector.setupMetrics(names, objects, period, nsamples)
+        self._update_metric_params()
+
+    def enable(self, names, objects):
+        """ Resumes metric collection for the specified metrics.
+        """
+        self.collector.enableMetrics(names, objects)
+
+    def disable(self, names, objects):
+        """ Suspends metric collection for the specified metrics.
+        """
+        self.collector.disableMetrics(names, objects)
+
+    def query(self, names, objects):
+        """ Retrieves collected metric values as well as some auxiliary
+        information. Returns an array of dictionaries, one dictionary per
+        metric. Each dictionary contains the following entries:
+        'name': metric name
+        'object': managed object this metric associated with
+        'unit': unit of measurement
+        'scale': divide 'values' by this number to get float numbers
+        'values': collected data
+        'values_as_string': pre-processed values ready for 'print' statement
+        """
+        (values, names_out, objects_out, indices, lengths) = self.collector.queryMetricsData(names, objects)
+        out = []
+        for i in xrange(0, len(names_out)):
+            metric = self.metrics[str(objects_out[i]) + "/" + str(names_out[i])]
+            unit = str(metric.getUnit())
+            if unit == '%':
+                scale = 1000.
+                fmt = '%.2f%s'
+            else:
+                scale = 1
+                fmt = '%d %s'
+            out.append({
+                'name':str(names_out[i]),
+                'object':str(objects_out[i]),
+                'unit':str(metric.getUnit()),
+                'scale':scale,
+                'values':[int(values[j]) for j in xrange(int(indices[i]), int(indices[i])+int(lengths[i]))],
+                'values_as_string':'['+', '.join([fmt % (int(values[j])/scale, unit) for j in xrange(int(indices[i]), int(indices[i])+int(lengths[i]))])+']'
+            })
+        return out
 
 g_hasreadline = 1
@@ -78 +154 @@
    return s.split()
    
-def startVm(mgr,vb,mach,type):
+def startVm(mgr,vb,mach,type,perf):
     session = mgr.getSessionObject(vb)
     uuid = mach.id
@@ -86 +162 @@
     rc = progress.resultCode
     print "Completed:", completed, "rc:",rc
-    if rc == 0:
+    if int(rc) == 0:
+        # @todo Nikolay, what is the point in ignoring exceptions?
         try:
-            vb.performanceCollector.setupMetrics(['*'], [mach], 10, 15)
+            perf.setup(['*'], [mach], 10, 15)
         except:
             pass
@@ -103 +180 @@
 
 def guestStats(ctx,mach):
-    collector = ctx['vb'].performanceCollector
-    (vals, names, objs, idxs, lens) = collector.queryMetricsData(["*"], [mach])
-    for i in range(0,len(names)):
-        valsStr = '[ '
-        for j in range(0, lens[i]):
-            valsStr += str(vals[int(idxs[i])+j])+' '
-        valsStr += ']'
-        print names[i],valsStr
+    for metric in ctx['perf'].query(["*"], [mach]):
+        print metric['name'], metric['values_as_string']
 
 def cmdExistingVm(ctx,mach,cmd):
@@ -217 +288 @@
     else:
         type = "gui"
-    startVm(ctx['mgr'], ctx['vb'], mach, type)
+    startVm(ctx['mgr'], ctx['vb'], mach, type, ctx['perf'])
     return 0
 
@@ -291 +362 @@
       print "Processor #%d speed: %dMHz" %(i,host.getProcessorSpeed(i))
                 
-   collector = ctx['vb'].performanceCollector
-  
-   (vals, names, objs, idxs, lens) = collector.queryMetricsData(["*"], [host])
-   for i in range(0,len(names)):
-       valsStr = '[ '
-       for j in range(0, lens[i]):
-           valsStr += str(vals[int(idxs[i])+j])+' '
-       valsStr += ']'
-       print names[i],valsStr
+   for metric in ctx['perf'].query(["*"], [host]):
+       print metric['name'], metric['values_as_string']
 
    return 0
@@ -360 +424 @@
     # last 150 secs maximum, (sample every 10 secs and keep up to 15 samples)
     try:
-        vbox.performanceCollector.setupMetrics(['*'], [vbox.host], 10, 15)
+        ctx['perf'].setup(['*'], [vbox.host], 10, 15)
     except:
         pass
@@ -380 +444 @@
 
     try:
-        vbox.performanceCollector.disableMetrics(['*'], [vbox.host])
+        # There is no need to disable metric collection. This is just an example.
+        ctx['perf'].disable(['*'], [vbox.host])
     except:
         pass