mirror of
https://github.com/facebook/sapling.git
synced 2024-10-07 15:27:13 +03:00
9090463607
This associates a transaction handle with a given repository object, and any additional calls to start new transactions reuse that transaction. For the 2700 patch import run, this brings the system time down from 1m20s to 50s, mostly by skipping backups of the dirstate file. (note, this patch does not change hg import to use the nested transaction, mq is the only user right now)
90 lines
2.5 KiB
Python
90 lines
2.5 KiB
Python
# 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):
|
|
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 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 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)
|
|
|