From a2bf2a77d14234748da050e16dc4b0cfd57a95e5 Mon Sep 17 00:00:00 2001
From: j <0x006A@0x2620.org>
Date: Sun, 14 Jun 2009 21:22:47 +0200
Subject: [PATCH] deal with files < 64k in oshash

---
 oxlib/file.py | 63 ++++++++++++++++++++++++++-------------------------
 1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/oxlib/file.py b/oxlib/file.py
index 0396959..38edfef 100644
--- a/oxlib/file.py
+++ b/oxlib/file.py
@@ -5,7 +5,7 @@ from __future__ import division
 import os
 import hashlib
 import sys
-import struct 
+import struct
 
 
 def sha1sum(filename):
@@ -20,37 +20,38 @@ def sha1sum(filename):
 
 '''
     os hash - http://trac.opensubtitles.org/projects/opensubtitles/wiki/HashSourceCodes
+    plus modification for files < 64k, buffer is filled with file data and padded with 0
 '''
-def oshash(filename): 
-    try: 
-        longlongformat = 'q'  # long long 
-        bytesize = struct.calcsize(longlongformat) 
-            
-        f = open(filename, "rb") 
-            
-        filesize = os.path.getsize(filename) 
-        hash = filesize 
-            
-        if filesize < 65536: 
-           return "SizeError" 
-         
-        for x in range(int(65536/bytesize)): 
-            buffer = f.read(bytesize) 
-            (l_value,)= struct.unpack(longlongformat, buffer)  
-            hash += l_value 
-            hash = hash & 0xFFFFFFFFFFFFFFFF #to remain as 64bit number  
-                 
+def oshash(filename):
+    try:
+        longlongformat = 'q'  # long long
+        bytesize = struct.calcsize(longlongformat)
 
-        f.seek(max(0,filesize-65536),0) 
-        for x in range(int(65536/bytesize)): 
-            buffer = f.read(bytesize) 
-            (l_value,)= struct.unpack(longlongformat, buffer)  
-            hash += l_value 
-            hash = hash & 0xFFFFFFFFFFFFFFFF 
-         
-        f.close() 
-        returnedhash =  "%016x" % hash 
-        return returnedhash 
-    except(IOError): 
+        f = open(filename, "rb")
+
+        filesize = os.path.getsize(filename)
+        hash = filesize
+        if filesize < 65536:
+            for x in range(int(filesize/bytesize)):
+                buffer = f.read(bytesize)
+                (l_value,)= struct.unpack(longlongformat, buffer)
+                hash += l_value
+                hash = hash & 0xFFFFFFFFFFFFFFFF #to remain as 64bit number
+        else:
+            for x in range(int(65536/bytesize)):
+                buffer = f.read(bytesize)
+                (l_value,)= struct.unpack(longlongformat, buffer)
+                hash += l_value
+                hash = hash & 0xFFFFFFFFFFFFFFFF #to remain as 64bit number
+            f.seek(max(0,filesize-65536),0)
+            for x in range(int(65536/bytesize)):
+                buffer = f.read(bytesize)
+                (l_value,)= struct.unpack(longlongformat, buffer)
+                hash += l_value
+                hash = hash & 0xFFFFFFFFFFFFFFFF
+        f.close()
+        returnedhash =  "%016x" % hash
+        return returnedhash
+    except(IOError):
         return "IOError"