| #!/usr/bin/python |
| |
| # Copyright 2011 Google Inc. All Rights Reserved. |
| |
| import os |
| import threading |
| |
| from utils import logger |
| from utils.file_utils import FileUtils |
| |
| |
| class ImageChecksummer(object): |
| class PerImageChecksummer(object): |
| 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 Exception("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 Exception("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 Exception("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 Exception, e: |
| logger.GetLogger().LogError("Could not compute checksum of image in label" |
| " '%s'."% label.name) |
| raise e |