tools/perf/profile_creators/cookie_profile_extender.py

   1 # Copyright 2015 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4 import multiprocessing
   5 import os
   6 import sqlite3
   7
   8 import page_sets
   9
  10 from profile_creators import fast_navigation_profile_extender
  11 from profile_creators import profile_safe_url_list
  12
  13 class CookieProfileExtender(
  14     fast_navigation_profile_extender.FastNavigationProfileExtender):
  15   """This extender fills in the cookie database.
  16
  17   By default, Chrome purges the cookie DB down to 3300 cookies. However, it
  18   won't purge cookies accessed in the last month. This means the extender needs
  19   to be careful not to create an artificially high number of cookies.
  20   """
  21   _COOKIE_DB_EXPECTED_SIZE = 3300
  22
  23   def __init__(self):
  24     # The rate limiting factors are fetching network resources and executing
  25     # javascript. There's not much to be done about the former, and having one
  26     # tab per logical core appears close to optimum for the latter.
  27     maximum_batch_size = multiprocessing.cpu_count()
  28     super(CookieProfileExtender, self).__init__(maximum_batch_size)
  29
  30     # A list of urls that have not yet been navigated to. This list will shrink
  31     # over time. Each navigation will add a diminishing number of new cookies,
  32     # since there's a high probability that the cookie is already present.
  33     self._page_set = page_sets.ProfileSafeUrlsPageSet()
  34     urls = []
  35     for user_story in self._page_set.user_stories:
  36       urls.append(user_story.url)
  37     self._navigation_urls = urls
  38
  39   def GetUrlIterator(self):
  40     """Superclass override."""
  41     return iter(self._navigation_urls)
  42
  43   def ShouldExitAfterBatchNavigation(self):
  44     """Superclass override."""
  45     return self._IsCookieDBFull()
  46
  47   def WebPageReplayArchivePath(self):
  48     return self._page_set.WprFilePathForUserStory(
  49         self._page_set.user_stories[0])
  50
  51   def FetchWebPageReplayArchives(self):
  52     """Superclass override."""
  53     self._page_set.wpr_archive_info.DownloadArchivesIfNeeded()
  54
  55   @staticmethod
  56   def _CookieCountInDB(db_path):
  57     """The number of cookies in the db at |db_path|."""
  58     connection = sqlite3.connect(db_path)
  59     try:
  60       cursor = connection.cursor()
  61       cursor.execute("select count(*) from cookies")
  62       cookie_count = cursor.fetchone()[0]
  63     except:
  64       raise
  65     finally:
  66       connection.close()
  67     return cookie_count
  68
  69   def _IsCookieDBFull(self):
  70     """Chrome does not immediately flush cookies to its database. It's possible
  71     that this method will return a false negative."""
  72     cookie_db_path = os.path.join(self.profile_path, "Default", "Cookies")
  73     try:
  74       cookie_count = CookieProfileExtender._CookieCountInDB(cookie_db_path)
  75     except sqlite3.OperationalError:
  76       # There will occasionally be contention for the SQLite database. This
  77       # shouldn't happen often, so ignore the errors.
  78       return False
  79
  80     return cookie_count > CookieProfileExtender._COOKIE_DB_EXPECTED_SIZE