Updated TODO
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Updated TODO
manifest hash: 007f50cbf11632362229853439d2610a1ad3f989
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.1 (GNU/Linux)
iD8DBQFCxF+7W7P1GVgWeRoRAg8MAJ9k3HXkpmHk3SRYw9FiqfHh8sEDFQCfc5il
2T+hyWgBwBTTHYpBeujq/20=
=cRVv
-----END PGP SIGNATURE-----
# transaction.py - simple journalling scheme for mercurial
#
# This transaction scheme is intended to gracefully handle program
# errors and interruptions. More serious failures like system crashes
# can be recovered with an fsck-like tool. As the whole repository is
# effectively log-structured, this should amount to simply truncating
# anything that isn't referenced in the changelog.
#
# Copyright 2005 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 os
import util
class transaction:
def __init__(self, opener, journal, after = None):
self.journal = None
# abort here if the journal already exists
if os.path.exists(journal):
raise "journal already exists - run hg recover"
self.opener = opener
self.after = after
self.entries = []
self.map = {}
self.journal = journal
self.file = open(self.journal, "w")
def __del__(self):
if self.entries: self.abort()
try: os.unlink(self.journal)
except: pass
def add(self, file, offset):
if file in self.map: return
self.entries.append((file, offset))
self.map[file] = 1
# add enough data to the journal to do the truncate
self.file.write("%s\0%d\n" % (file, offset))
self.file.flush()
def close(self):
self.file.close()
self.entries = []
if self.after:
util.rename(self.journal, self.after)
else:
os.unlink(self.journal)
def abort(self):
if not self.entries: return
print "transaction abort!"
for f, o in self.entries:
try:
self.opener(f, "a").truncate(o)
except:
print "failed to truncate", f
self.entries = []
print "rollback completed"
def rollback(opener, file):
for l in open(file).readlines():
f, o = l.split('\0')
opener(f, "a").truncate(int(o))
os.unlink(file)