Synced repos to: 58208

1 files changed, 49 insertions, 0 deletions

diff --git a/crosperf/image_checksummer.py b/crosperf/image_checksummer.py
new file mode 100644
index 00000000..f75dc944
--- /dev/null
+++ b/crosperf/image_checksummer.py
@@ -0,0 +1,49 @@
+#!/usr/bin/python
+
+# Copyright 2011 Google Inc. All Rights Reserved.
+
+import threading
+from utils import logger
+from utils.file_utils import FileUtils
+
+
+class ImageChecksummer(object):
+  class PerImageChecksummer(object):
+    def __init__(self, filename):
+      self._lock = threading.Lock()
+      self.filename = filename
+      self._checksum = None
+
+    def Checksum(self):
+      with self._lock:
+        if not self._checksum:
+          logger.GetLogger().LogOutput("Computing checksum for '%s'." %
+                                       self.filename)
+          self._checksum = FileUtils().Md5File(self.filename)
+          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, filename):
+    with self._lock:
+      if filename not in self._per_image_checksummers:
+        self._per_image_checksummers[filename] = (ImageChecksummer.
+                                                  PerImageChecksummer(filename))
+      checksummer = self._per_image_checksummers[filename]
+
+    try:
+      return checksummer.Checksum()
+    except Exception, e:
+      logger.GetLogger().LogError("Could not compute checksum of file '%s'."
+                                  % filename)
+      raise e