tools: Local tests for the speculative prefetch predictor.

tools/resource_prefetch_predictor/prefetch_predictor_common.py

Index: tools/resource_prefetch_predictor/prefetch_predictor_common.py
diff --git a/tools/resource_prefetch_predictor/prefetch_predictor_common.py b/tools/resource_prefetch_predictor/prefetch_predictor_common.py
new file mode 100644
index 0000000000000000000000000000000000000000..aeed9388a63597fb265c2327dc2f5fa250812696
--- /dev/null
+++ b/tools/resource_prefetch_predictor/prefetch_predictor_common.py
@@ -0,0 +1,48 @@
+# 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.
+
+"""Common utils for the speculative resource prefetch evaluation."""
+
+import argparse

[pasko, 2016/11/30 12:53:46]

not necessary?

[Benoit L, 2016/11/30 15:25:50]

Done.

+import logging
+import os
+import sys
+
+_SRC_PATH = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), os.pardir, os.pardir))
+
+sys.path.append(os.path.join(_SRC_PATH, 'third_party', 'catapult', 'devil'))
+from devil.android import device_utils
+
+sys.path.append(os.path.join(_SRC_PATH, 'tools', 'android', 'loading'))
+import controller
+from options import OPTIONS
+
+
+def FindDevice(device_id):

[pasko, 2016/11/30 12:53:46]

can we use device_setup.GetDeviceFromSerial()?

[Benoit L, 2016/11/30 15:25:50]

Thanks!

Done.

+  """Returns a device matching |device_id| or the first one if None, or None."""
+  devices = device_utils.DeviceUtils.HealthyDevices()
+  if device_id is None:
+    return devices[0]
+  matching_devices = [d for d in devices if str(d) == device_id]

[pasko, 2016/11/30 12:53:46]

nit: constructing the list to only get the first element?

also 4 lines but more readable for my imperative brain:

for d in devices:
  if str(d) == device_id:
    return d
return None # or throw, or just use device_setup.GetDeviceFromSerial

just a nit, not necessary to do change anything

[Benoit L, 2016/11/30 15:25:50]

Acknowledged.

+  if not matching_devices:
+    return None
+  return matching_devices[0]
+
+
+def Setup(device, additional_flags=None):
+  """Sets up a device and returns an instance of RemoteChromeController."""

[pasko, 2016/11/30 12:53:46]

should document |additional_flags| and the class for |device|

[Benoit L, 2016/11/30 15:25:50]

Done.

+  if not device.HasRoot():
+    device.EnableRoot()
+  chrome_controller = controller.RemoteChromeController(device)
+  device.ForceStop(OPTIONS.ChromePackage().package)
+  if additional_flags is not None:
+    chrome_controller.AddChromeArguments(additional_flags)
+  chrome_controller.ResetBrowserState()
+  return chrome_controller
+
+
+def DatabaseDevicePath():
+  return ('/data/user/0/%s/app_chrome/Default/Network Action Predictor' %
+          OPTIONS.ChromePackage().package)