index writing now creates a sha on the content making it possible to write valid indices after manually removing or altering entriesgst

1 files changed, 52 insertions, 0 deletions

diff --git a/lib/git/utils.py b/lib/git/utils.py
index 2aa8d33e..cdc7c55b 100644
--- a/lib/git/utils.py
+++ b/lib/git/utils.py
@@ -6,6 +6,58 @@
 
 import os
 
+try:
+    import hashlib
+except ImportError:
+    import sha
+
+def make_sha(source=''):
+    """
+    A python2.4 workaround for the sha/hashlib module fiasco
+    
+	Note
+		From the dulwich project
+	"""
+    try:
+        return hashlib.sha1(source)
+    except NameError:
+        sha1 = sha.sha(source)
+        return sha1
+
+
+class SHA1Writer(object):
+    """
+    Wrapper around a file-like object that remembers the SHA1 of 
+    the data written to it. It will write a sha when the stream is closed
+    or if the asked for explicitly usign write_sha.
+    
+    Note:
+    	Based on the dulwich project
+    """
+    __slots__ = ("f", "sha1")
+    
+    def __init__(self, f):
+        self.f = f
+        self.sha1 = make_sha("")
+
+    def write(self, data):
+        self.sha1.update(data)
+        self.f.write(data)
+
+    def write_sha(self):
+        sha = self.sha1.digest()
+        self.f.write(sha)
+        return sha
+
+    def close(self):
+        sha = self.write_sha()
+        self.f.close()
+        return sha
+
+    def tell(self):
+        return self.f.tell()
+
+
 class LazyMixin(object):
 	"""
 	Base class providing an interface to lazily retrieve attribute values upon