"""
changegroup.py - Mercurial changegroup manipulation functions
Copyright 2006 Matt Mackall <mpm@selenic.com>
This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""
import struct
from i18n import gettext as _
from demandload import *
demandload(globals(), "util")
def getchunk(source):
"""get a chunk from a changegroup"""
d = source.read(4)
if not d:
return ""
l = struct.unpack(">l", d)[0]
if l <= 4:
return ""
d = source.read(l - 4)
if len(d) < l - 4:
raise util.Abort(_("premature EOF reading chunk"
" (got %d bytes, expected %d)")
% (len(d), l - 4))
return d
def chunkiter(source):
"""iterate through the chunks in source"""
while 1:
c = getchunk(source)
if not c:
break
yield c
def genchunk(data):
"""build a changegroup chunk"""
header = struct.pack(">l", len(data)+ 4)
return "%s%s" % (header, data)
def closechunk():
return struct.pack(">l", 0)