def get_delta(self, old_buf, new_buf):
u"""Return delta buffer from old to new"""
sigfile = librsync.SigFile(io.BytesIO(old_buf))
sig = sigfile.read()
assert not sigfile.close()
deltafile = librsync.DeltaFile(sig, io.BytesIO(new_buf))
deltabuf = deltafile.read()
assert not deltafile.close()
return deltabuf
def librsyncDeltaFile(filename, signature, deltafile):
bufsize = 1024 * 1024
filename = forceFilename(filename)
deltafile = forceFilename(deltafile)
logger.debug("Creating deltafile {!r} on base of {!r}", deltafile,
filename)
try:
with open(filename, "rb") as f:
with open(deltafile, "wb") as df:
with closing(librsync.DeltaFile(signature, f)) as ldf:
data = True
while data:
data = ldf.read(bufsize)
df.write(data)
except Exception as e:
raise RuntimeError(u"Failed to write delta file %s: %s" %
(deltafile, forceUnicode(e)))
