Mercurial > hg > gitserve
view mercurial/transaction.py @ 859:6390c377a9e6
Trap OSError when deleting env vars
On the other OS, it seems that case insensitivity for
environment vars can bite users when using some unknown
combination of python 2.4.1 and win2kSP4+minsys (and
probably other vversions of these softwares).
The best way to avoid problems in those weird cases is to
ignore OSError exception during env var deletion.
author | Edouard Gomez <ed.gomez@free.fr> |
---|---|
date | Tue, 09 Aug 2005 09:36:34 -0800 |
parents | 0902ffece4b4 |
children | 6d5a62a549fa |
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# 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, report, 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.report = report self.opener = opener self.after = after self.entries = [] self.map = {} self.journal = journal self.file = open(self.journal, "w") def __del__(self): if self.journal: if self.entries: self.abort() self.file.close() 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: self.after() else: os.unlink(self.journal) self.journal = None def abort(self): if not self.entries: return self.report("transaction abort!\n") for f, o in self.entries: try: self.opener(f, "a").truncate(o) except: self.report("failed to truncate %s\n" % f) self.entries = [] self.report("rollback completed\n") def rollback(opener, file): for l in open(file).readlines(): f, o = l.split('\0') opener(f, "a").truncate(int(o)) os.unlink(file)