def MeasurePage(self, _, tab, results):
"""Although this is called MeasurePage, we're actually using this function
to cycle through each tab that was opened via DidNavigateToPage and
thenrecord a single histogram for the tab switching metric.
"""
histogram_name = 'MPArch.RWH_TabSwitchPaintDuration'
histogram_type = 'getBrowserHistogram'
first_histogram = histogram_module.GetHistogramFromDomAutomation(
histogram_type, histogram_name, tab)
prev_histogram = first_histogram
for i in xrange(len(tab.browser.tabs)):
t = tab.browser.tabs[i]
t.Activate()
def _IsDone():
cur_histogram = histogram_module.GetHistogramFromDomAutomation(
histogram_type, histogram_name, tab)
diff_histogram = histogram_module.SubtractHistogram(
cur_histogram, prev_histogram)
return diff_histogram
util.WaitFor(_IsDone, 30)
prev_histogram = histogram_module.GetHistogramFromDomAutomation(
histogram_type, histogram_name, tab)
last_histogram = histogram_module.GetHistogramFromDomAutomation(
histogram_type, histogram_name, tab)
diff_histogram = histogram_module.SubtractHistogram(
last_histogram, first_histogram)
results.AddSummary(histogram_name,
'',
diff_histogram,
data_type='unimportant-histogram')
def GetValue(self, page, tab, results):
data = self._GetHistogramFromDomAutomation(tab)
if not data:
return
new_histogram = histogram_module.SubtractHistogram(
data, self._start_values[page.url + self.name])
results.Add(self.name,
self.units,
new_histogram,
data_type='unimportant-histogram')
def testSubtractHistogram(self):
baseline_histogram = """{"count": 3, "buckets": [
{"low": 1, "high": 2, "count": 1},
{"low": 2, "high": 3, "count": 2}]}"""
histogram = """{"count": 14, "buckets": [
{"low": 1, "high": 2, "count": 1},
{"low": 2, "high": 3, "count": 3},
{"low": 3, "high": 4, "count": 10}]}"""
new_histogram = json.loads(
histogram_module.SubtractHistogram(histogram, baseline_histogram))
new_buckets = dict()
for b in new_histogram['buckets']:
new_buckets[b['low']] = b['count']
self.assertFalse(1 in new_buckets)
self.assertEquals(1, new_buckets[2])
self.assertEquals(10, new_buckets[3])
def _IsDone():
cur_histogram = histogram_module.GetHistogramFromDomAutomation(
histogram_type, histogram_name, tab)
diff_histogram = histogram_module.SubtractHistogram(
cur_histogram, prev_histogram)
return diff_histogram