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# Any copyright is dedicated to the Public Domain.
# http://creativecommons.org/publicdomain/zero/1.0/
from __future__ import absolute_import
import time
import os
from marionette_harness import MarionetteTestCase
LABELS_SCRIPT_PRELOADER_REQUESTS = {
"Hit": "0",
"HitChild": "1",
"Miss": "2",
}
class TestScriptPreloader(MarionetteTestCase):
def test_preloader_requests_histogram(self):
start_time = time.time()
self.invalidate_caches()
self.marionette.restart(clean=False, in_app=True)
histogram = self.get_histogram("SCRIPT_PRELOADER_REQUESTS")
misses = histogram.get(LABELS_SCRIPT_PRELOADER_REQUESTS["Miss"], 0)
hits = histogram.get(LABELS_SCRIPT_PRELOADER_REQUESTS["Hit"], 0)
child_hits = histogram.get(LABELS_SCRIPT_PRELOADER_REQUESTS["HitChild"], 0)
self.assertMuchGreaterThan(misses, hits)
self.assertMuchGreaterThan(misses, child_hits)
profile = self.marionette.profile_path
self.wait_for_file_change(
start_time, "{}/startupCache/scriptCache.bin".format(profile)
)
self.wait_for_file_change(
start_time, "{}/startupCache/scriptCache-child.bin".format(profile)
)
self.marionette.restart(clean=False, in_app=True)
histogram = self.get_histogram("SCRIPT_PRELOADER_REQUESTS")
misses = histogram.get(LABELS_SCRIPT_PRELOADER_REQUESTS["Miss"], 0)
hits = histogram.get(LABELS_SCRIPT_PRELOADER_REQUESTS["Hit"], 0)
child_hits = histogram.get(LABELS_SCRIPT_PRELOADER_REQUESTS["HitChild"], 0)
# This is just heuristic. We certainly want to be made aware if this ratio
# changes and we didn't intend it to.
self.assertSimilar(misses, hits)
self.assertNotEqual(child_hits, 0)
def assertMuchGreaterThan(self, lhs, rhs):
self.assertTrue(lhs > 4 * rhs)
def assertSimilar(self, lhs, rhs):
self.assertTrue(lhs < 2 * rhs)
self.assertTrue(lhs > rhs / 2)
def wait_for_file_change(self, start_time, path):
expires = time.time() + 20
while True:
try:
if os.stat(path).st_mtime > start_time:
return
if time.time() > expires:
raise Exception("Never observed file change for {}".format(path))
time.sleep(1)
except OSError:
pass
def wait_for_observer_notification(self, name):
with self.marionette.using_context(self.marionette.CONTEXT_CHROME):
return self.marionette.execute_script(
"""
let [resolve] = arguments;
Services.obs.addObserver(() => resolve(), "{}");
""".format(
name
)
)
def get_histogram(self, name):
with self.marionette.using_context(self.marionette.CONTEXT_CHROME):
return self.marionette.execute_script(
"""
let snapshot = Services.telemetry.getSnapshotForHistograms("main", true);
return snapshot.parent.{}.values;
""".format(
name
)
)
def invalidate_caches(self):
with self.marionette.using_context(self.marionette.CONTEXT_CHROME):
return self.marionette.execute_script(
"Services.obs.notifyObservers(null, 'startupcache-invalidate');"
)
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