| # Copyright 2011 Google Inc. All Rights Reserved. |
| """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 |