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# -*- coding: utf-8 -*-
# Copyright 2011 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.
"""Compute image checksum."""
from __future__ import print_function
import os
import threading
from cros_utils import logger
from cros_utils.file_utils import FileUtils
class ImageChecksummer(object):
"""Compute image checksum."""
class PerImageChecksummer(object):
"""Compute checksum for an image."""
def __init__(self, label, log_level):
self._lock = threading.Lock()
self.label = label
self._checksum = None
self.log_level = log_level
def Checksum(self):
with self._lock:
if not self._checksum:
logger.GetLogger().LogOutput(
"Acquiring checksum for '%s'." % self.label.name)
self._checksum = None
if self.label.image_type != 'local':
raise RuntimeError('Called Checksum on non-local image!')
if self.label.chromeos_image:
if os.path.exists(self.label.chromeos_image):
self._checksum = FileUtils().Md5File(
self.label.chromeos_image, log_level=self.log_level)
logger.GetLogger().LogOutput('Computed checksum is '
': %s' % self._checksum)
if not self._checksum:
raise RuntimeError('Checksum computing error.')
logger.GetLogger().LogOutput('Checksum is: %s' % self._checksum)
return self._checksum
_instance = None
_lock = threading.Lock()
_per_image_checksummers = {}
def __new__(cls, *args, **kwargs):
with cls._lock:
if not cls._instance:
cls._instance = super(ImageChecksummer, cls).__new__(
cls, *args, **kwargs)
return cls._instance
def Checksum(self, label, log_level):
if label.image_type != 'local':
raise RuntimeError('Attempt to call Checksum on non-local image.')
with self._lock:
if label.name not in self._per_image_checksummers:
self._per_image_checksummers[label.name] = (
ImageChecksummer.PerImageChecksummer(label, log_level))
checksummer = self._per_image_checksummers[label.name]
try:
return checksummer.Checksum()
except:
logger.GetLogger().LogError('Could not compute checksum of image in label'
" '%s'." % label.name)
raise