X-Git-Url: https://code.grnet.gr/git/snf-image-creator/blobdiff_plain/ae48a082b638284012de78a30c8374ba689eb0b7..aeb95900f10211f2d3c8ffead154a44121a2d5b5:/image_creator/util.py

diff --git a/image_creator/util.py b/image_creator/util.py
index f912fe7..bd34222 100644
--- a/image_creator/util.py
+++ b/image_creator/util.py
@@ -31,7 +31,13 @@
 # interpreted as representing official policies, either expressed
 # or implied, of GRNET S.A.
 
+import sys
 import pbs
+import hashlib
+
+
+class FatalError(Exception):
+    pass
 
 
 def get_command(command):
@@ -46,3 +52,32 @@ def get_command(command):
         return pbs.__getattr__(command)
     except pbs.CommadNotFount as e:
         return find_sbin_command(command, e)
+
+
+class MD5:
+    def __init__(self, output):
+        self.out = output
+
+    def compute(self, filename, size):
+
+        MB = 2 ** 20
+        BLOCKSIZE = 4 * MB  # 4MB
+
+        prog_size = ((size + MB - 1) // MB)  # in MB
+        progressbar = self.out.Progress(prog_size, "Calculating md5sum", 'mb')
+        md5 = hashlib.md5()
+        with open(filename, "r") as src:
+            left = size
+            while left > 0:
+                length = min(left, BLOCKSIZE)
+                data = src.read(length)
+                md5.update(data)
+                left -= length
+                progressbar.goto((size - left) // MB)
+
+        checksum = md5.hexdigest()
+        progressbar.success(checksum)
+
+        return checksum
+
+# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :