[Android] Redesigns the sharder to allow replicated vs distributed tests

build/android/pylib/instrumentation/dispatch.py

-# Copyright (c) 2013 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.
-
-"""Dispatches the instrumentation tests."""
-
-import logging
-import os
-
-from pylib import android_commands
-from pylib import constants
-from pylib.base import base_test_result
-from pylib.base import shard
-from pylib.utils import report_results
-
-import test_package
-import test_runner
-
-
-def Dispatch(options):
-  """Dispatches instrumentation tests onto connected device(s).
-
-  If possible, this method will attempt to shard the tests to
-  all connected devices. Otherwise, dispatch and run tests on one device.
-
-  Args:
-    options: Command line options.
-
-  Returns:
-    A tuple of (base_test_result.TestRunResults object, exit code).
-
-  Raises:
-    Exception: when there are no attached devices.
-  """
-  test_pkg = test_package.TestPackage(options.test_apk_path,
-                                      options.test_apk_jar_path)
-  tests = test_pkg._GetAllMatchingTests(
-      options.annotations, options.exclude_annotations, options.test_filter)
-  if not tests:
-    logging.error('No instrumentation tests to run with current args.')
-    return (base_test_result.TestRunResults(), constants.ERROR_EXIT_CODE)
-
-  attached_devices = android_commands.GetAttachedDevices()
-  if not attached_devices:
-    raise Exception('There are no devices online.')
-
-  if options.test_device:
-    assert options.test_device in attached_devices
-    attached_devices = [options.test_device]
-
-  if len(attached_devices) > 1 and options.wait_for_debugger:
-    logging.warning('Debugger can not be sharded, using first available device')
-    attached_devices = attached_devices[:1]
-
-  def TestRunnerFactory(device, shard_index):
-    return test_runner.TestRunner(
-        options, device, shard_index, test_pkg, [])
-
-  return shard.ShardAndRunTests(TestRunnerFactory, attached_devices, tests,
-                                options.build_type,
-                                test_timeout=None,
-                                num_retries=options.num_retries)