Changeset 7079 for main/waeup.sirp/trunk

Timestamp:

11 Nov 2011, 10:02:10 (13 years ago)

Author:

uli

Message:

Add helper to determine size of files reliably and for all regular
kinds of file/file-like objects.

File:

• main/waeup.sirp/trunk/src/waeup/sirp/utils/helpers.py (modified) (1 diff)

main/waeup.sirp/trunk/src/waeup/sirp/utils/helpers.py

@@ -429 +429 @@
         return u'%.2f MB' % (number / 1024**2,)
     return u'%.2f GB' % (number / 1024**3,)
+
+def file_size(file_like_obj):
+    """Determine file size in most effective manner.
+
+    Returns the number of bytes in a file. This function works for
+    both, real files as well as file-like objects like cStringIO based
+    'files'.
+
+    Example:
+
+      >>> from cStringIO import StringIO
+      >>> file_size(StringIO('my file content'))
+      15
+
+    Please note that this function expects the file-like object passed
+    in to be at first reading position (it does no seek(0)) and that
+    when finished the file pointer might be at end of file.
+    """
+    if hasattr(file_like_obj, 'fileno'):
+        return os.fstat(file_like_obj.fileno())[6]
+    file_like_obj.seek(0, 2) # seek to last position in file
+    return file_like_obj.tell()