convert global variable to class member (#522)

This allows the tests to pass on archs with non 4K pages.

Signed-off-by: Stefano Torresi <[email protected]>

Author: stefanotorresi

prometheus_client/process_collector.py

@@ -31,6 +31,8 @@ def __init__(self, namespace='', pid=lambda: 'self', proc='/proc', registry=REGI
         except (ValueError, TypeError, AttributeError, OSError):
             pass
 
+        self._pagesize = _PAGESIZE
+
         # This is used to test if we can access /proc.
         self._btime = 0
         try:
@@ -60,7 +62,7 @@ def collect(self):
             vmem = GaugeMetricFamily(self._prefix + 'virtual_memory_bytes',
                                      'Virtual memory size in bytes.', value=float(parts[20]))
             rss = GaugeMetricFamily(self._prefix + 'resident_memory_bytes', 'Resident memory size in bytes.',
-                                    value=float(parts[21]) * _PAGESIZE)
+                                    value=float(parts[21]) * self._pagesize)
             start_time_secs = float(parts[19]) / self._ticks
             start_time = GaugeMetricFamily(self._prefix + 'start_time_seconds',
                                            'Start time of the process since unix epoch in seconds.',

tests/test_process_collector.py

@@ -14,6 +14,7 @@ def setUp(self):
     def test_working(self):
         collector = ProcessCollector(proc=self.test_proc, pid=lambda: 26231, registry=self.registry)
         collector._ticks = 100
+        collector._pagesize = 4096
 
         self.assertEqual(17.21, self.registry.get_sample_value('process_cpu_seconds_total'))
         self.assertEqual(56274944.0, self.registry.get_sample_value('process_virtual_memory_bytes'))
@@ -26,6 +27,7 @@ def test_working(self):
     def test_namespace(self):
         collector = ProcessCollector(proc=self.test_proc, pid=lambda: 26231, registry=self.registry, namespace='n')
         collector._ticks = 100
+        collector._pagesize = 4096
 
         self.assertEqual(17.21, self.registry.get_sample_value('n_process_cpu_seconds_total'))
         self.assertEqual(56274944.0, self.registry.get_sample_value('n_process_virtual_memory_bytes'))
@@ -38,6 +40,7 @@ def test_namespace(self):
     def test_working_584(self):
         collector = ProcessCollector(proc=self.test_proc, pid=lambda: "584\n", registry=self.registry)
         collector._ticks = 100
+        collector._pagesize = 4096
 
         self.assertEqual(0.0, self.registry.get_sample_value('process_cpu_seconds_total'))
         self.assertEqual(10395648.0, self.registry.get_sample_value('process_virtual_memory_bytes'))
@@ -49,6 +52,7 @@ def test_working_584(self):
     def test_working_fake_pid(self):
         collector = ProcessCollector(proc=self.test_proc, pid=lambda: 123, registry=self.registry)
         collector._ticks = 100
+        collector._pagesize = 4096
 
         self.assertEqual(None, self.registry.get_sample_value('process_cpu_seconds_total'))
         self.assertEqual(None, self.registry.get_sample_value('process_virtual_memory_bytes'))