Teach walk code about absolute paths.
The first consequence of this is that absolute and relative paths now
all work in the same way. The second is that paths that lie outside
the repository now cause an error to be reported, instead of something
arbitrary and expensive being done.
Internally, all of the serious work is in the util package. The new
canonpath function takes an arbitrary path and either returns a
canonical path or raises an error. Because it needs to know where the
repository root is, it must be fed a repository or dirstate object, which
has given commands.matchpats and friends a new parameter to pass along.
The util.matcher function uses this to canonicalise globs and relative
path names.
Meanwhile, I've moved the Abort exception from commands to util, and
killed off the redundant util.CommandError exception.
# 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)