make appendfile simpler so it does not break with revlogng on windows.
it used to cache open files. this made revlogng break because it wants
to rename files when splitting .i into .i/.d, but cannot rename or unlink
open files on windows.
new code is bit slower, but safe on linux and windows. proper fix for
too many open/close of changelog/manifest belongs in different place.
can get 10% speed improvement back.
# 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
from i18n import gettext as _
class transaction(object):
def __init__(self, report, opener, journal, after=None):
self.journal = None
# abort here if the journal already exists
if os.path.exists(journal):
raise AssertionError(_("journal already exists - run hg recover"))
self.count = 1
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, data=None):
if file in self.map: return
self.entries.append((file, offset, data))
self.map[file] = len(self.entries) - 1
# add enough data to the journal to do the truncate
self.file.write("%s\0%d\n" % (file, offset))
self.file.flush()
def find(self, file):
if file in self.map:
return self.entries[self.map[file]]
return None
def replace(self, file, offset, data=None):
if file not in self.map:
raise KeyError(file)
index = self.map[file]
self.entries[index] = (file, offset, data)
self.file.write("%s\0%d\n" % (file, offset))
self.file.flush()
def nest(self):
self.count += 1
return self
def running(self):
return self.count > 0
def close(self):
self.count -= 1
if self.count != 0:
return
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, ignore 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):
files = {}
for l in open(file).readlines():
f, o = l.split('\0')
files[f] = o
for f in files:
o = files[f]
opener(f, "a").truncate(int(o))
os.unlink(file)