client/profilers/pgo/pgo.py

# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""
This is a profiler class for copying Profile-Guided-Optimization (PGO) data
files back to the host. When Chrome is built with -fprofile-generate, it dumps
its PGO data in a directory that this test copies back to test.profdir.

The PGO data is found where the build happens in the chroot, which is hardcoded
as the source_dir below.
"""

import logging
import os
import shutil
import tarfile

from autotest_lib.client.bin import profiler
from autotest_lib.client.common_lib import error
from autotest_lib.client.cros import cros_ui


class pgo(profiler.profiler):
    """The pgo profiler collects PGO data for Chrome."""
    version = 1

    def initialize(self, source_dir='/tmp/pgo/chrome'):
        self._source_dir = source_dir


    def start(self, test):
        # Remove the .gcda files first.
        if os.path.exists(self._source_dir):
            shutil.rmtree(self._source_dir)


    def stop(self, test):
        if not cros_ui.stop_and_wait_for_chrome_to_exit(timeout_secs=40):
            raise error.TestError('Could not stop Chrome')
        if os.path.isdir(self._source_dir):
            tar = tarfile.open(name=os.path.join(test.profdir, 'pgo.tar.bz2'),
                               mode='w:bz2')
            tar.add(self._source_dir, arcname='chrome', recursive=True)
            tar.close()
            versionfile = '/opt/google/chrome/profilelocation'
            if os.path.isfile(versionfile):
               shutil.copyfile(versionfile,
                               os.path.join(test.profdir, 'profiledestination'))
        else:
            logging.error('PGO dir: %s not found', self._source_dir)
        cros_ui.start(wait_for_login_prompt=False)