Simplify/correct finding the hg executable (fixes issue644)
Simply use find_exe('hg') as the default value for $HG and require to manually
set it if you have special requirements.
While the default will not always be 100% correct (i.e. the identical hg
version) for many users it is and for the others the hg executable found in
the PATH should do most things correctly.
Developers or other users with multiple installs can set $HG or run something
like util.set_hgexecutable in their shell or python scripts.
Additionally util.hgexecutable() is now available so extensions can access
the value with a public interface, too.
# 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, 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.
from i18n import _
import os
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)