1 files changed, 96 insertions, 0 deletions
diff --git a/catapult/telemetry/telemetry/page/cache_temperature.py b/catapult/telemetry/telemetry/page/cache_temperature.py
new file mode 100644
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+++ b/catapult/telemetry/telemetry/page/cache_temperature.py
@@ -0,0 +1,96 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Cache temperature specifies how the browser cache should be configured before
+the page run.
+
+See design doc for details:
+https://docs.google.com/document/u/1/d/12D7tkhZi887g9d0U2askU9JypU_wYiEI7Lw0bfwxUgA
+"""
+
+import logging
+
+import py_utils
+
+# Default Cache Temperature. The page doesn't care which browser cache state
+# it is run on.
+ANY = 'any'
+# Emulates PageCycler V1 cold runs. Clears system DNS cache, browser DiskCache,
+# net/ predictor cache, and net/ host resolver cache.
+PCV1_COLD = 'pcv1-cold'
+# Emulates PageCycler V1 warm runs. Ensures that the page was visited at least
+# once just before the run.
+PCV1_WARM = 'pcv1-warm'
+
+class MarkTelemetryInternal(object):
+
+  def __init__(self, browser, identifier):
+    self.browser = browser
+    self.identifier = identifier
+
+  def __enter__(self):
+    # TODO(catapult:#3028): Fix interpolation of JavaScript values.
+    self.browser.tabs[0].ExecuteJavaScript(
+        """console.time('telemetry.internal.{0}.start');""".format(
+          self.identifier))
+    # TODO(catapult:#3028): Fix interpolation of JavaScript values.
+    self.browser.tabs[0].ExecuteJavaScript(
+        """console.timeEnd('telemetry.internal.{0}.start');""".format(
+          self.identifier))
+    return self
+
+  def __exit__(self, exception_type, exception_value, traceback):
+    if exception_type:
+      return True
+
+    # TODO(catapult:#3028): Fix interpolation of JavaScript values.
+    self.browser.tabs[0].ExecuteJavaScript(
+        """console.time('telemetry.internal.{0}.end');""".format(
+          self.identifier))
+    # TODO(catapult:#3028): Fix interpolation of JavaScript values.
+    self.browser.tabs[0].ExecuteJavaScript(
+        """console.timeEnd('telemetry.internal.{0}.end');""".format(
+          self.identifier))
+    return True
+
+def EnsurePageCacheTemperature(page, browser, previous_page=None):
+  temperature = page.cache_temperature
+  logging.info('PageCacheTemperature: %s', temperature)
+
+  if temperature == ANY:
+    return
+
+  if temperature == PCV1_COLD:
+    if previous_page is None:
+      with MarkTelemetryInternal(browser, 'ensure_diskcache'):
+        tab = browser.tabs[0]
+        tab.Navigate("http://does.not.exist")
+        tab.WaitForDocumentReadyStateToBeComplete()
+
+    any_tab = browser.tabs[0]
+    any_tab.ClearCache(force=True)
+  elif temperature == PCV1_WARM:
+    if (previous_page is not None and
+        previous_page.url == page.url and
+        (previous_page.cache_temperature == PCV1_COLD or
+            previous_page.cache_temperature == PCV1_WARM)):
+      if '#' in page.url:
+        # Navigate to inexistent URL to avoid in-page hash navigation.
+        # Note: Unlike PCv1, PCv2 iterates the same URL for different cache
+        #       configurations. This may issue blink in-page hash navigations,
+        #       which isn't intended here.
+        with MarkTelemetryInternal(browser, 'avoid_double_hash_navigation'):
+          tab = browser.tabs[0]
+          tab.Navigate("http://does.not.exist")
+          tab.WaitForDocumentReadyStateToBeComplete()
+      return
+
+    with MarkTelemetryInternal(browser, 'warmCache'):
+      tab = browser.tabs[0]
+      tab.Navigate(page.url)
+      py_utils.WaitFor(tab.HasReachedQuiescence, 60)
+      tab.WaitForDocumentReadyStateToBeComplete()
+      tab.Navigate("about:blank")
+      tab.WaitForDocumentReadyStateToBeComplete()