| # -*- coding: utf-8 -*- |
| # Copyright 2011 The ChromiumOS Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Compute image checksum.""" |
| |
| |
| 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 |