1 files changed, 69 insertions, 0 deletions
diff --git a/crosperf/image_checksummer.py b/crosperf/image_checksummer.py
new file mode 100644
index 00000000..e330084e
--- /dev/null
+++ b/crosperf/image_checksummer.py
@@ -0,0 +1,69 @@
+# 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