From 9d359709945ec9026564636bb8c313024f3bad75 Mon Sep 17 00:00:00 2001
From: David Anderson <davea@ssl.berkeley.edu>
Date: Tue, 23 Nov 2010 22:16:24 +0000
Subject: [PATCH] - server scripts (e.g. update_versions):     compute MD5
 checksums be reading files in pieces instead     of reading whole file into
 memory.  From Tolu Aina

svn path=/trunk/boinc/; revision=22743
---
 checkin_notes     |  8 ++++++++
 py/Boinc/tools.py | 24 ++++++++++++++++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/checkin_notes b/checkin_notes
index be879be05a..b60f3c7bcf 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -8359,3 +8359,11 @@ David  23 Nov 2010
         cpu_sched.cpp
     lib/
         gui_rpc_client_ops.cpp
+
+David  23 Nov 2010
+    - server scripts (e.g. update_versions):
+        compute MD5 checksums be reading files in pieces instead
+        of reading whole file into memory.  From Tolu Aina
+
+    py/Boinc/
+        tools.py
diff --git a/py/Boinc/tools.py b/py/Boinc/tools.py
index a484c2f3d6..d432114bd8 100644
--- a/py/Boinc/tools.py
+++ b/py/Boinc/tools.py
@@ -44,8 +44,28 @@ def make_uuid():
     return binascii.hexlify(urandom(16))
 
 def md5_file(path):
-    """Return a 16-digit MD5 hex digest of a file's contents"""
-    return md5.new(open(path).read()).hexdigest()
+    """
+    Return a 16-digit MD5 hex digest of a file's contents
+    Read the file in chunks 
+    """
+
+    chunk = 8096
+
+    try:
+        checksum = md5()
+    except NameError:
+        checksum = md5.new()
+
+    fp = open(path, 'r')
+    while True:
+        buffer = fp.read(chunk)
+        if not buffer:
+            break
+        checksum.update(buffer)
+
+    fp.close()
+
+    return checksum
 
 def file_size(path):
     """Return the size of a file"""