import and startup cleanups
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import and startup cleanups
add commands:run()
add copyright notice to commands
eliminate/reorganize imports to speed up start time:
0.5b:
$ time bash -c 'for i in `seq 100`; do ~/bin/hg > /dev/null; done'
real 0m7.718s
user 0m6.719s
sys 0m0.794s
new:
$ time bash -c 'for i in `seq 100`; do hg > /dev/null; done'
real 0m2.171s
user 0m1.684s
sys 0m0.444s
just python:
$ time bash -c 'for i in `seq 100`; do python -c pass; done'
real 0m0.988s
user 0m0.771s
sys 0m0.207s
Ignoring the fixed cost of loading the Python interpreter, we're 5.6
times faster. With the Python load time, we're still 3.5 times faster.
manifest hash: acce5882a55c76eb165316f5741724c8ce4ef587
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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
class transaction:
def __init__(self, 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.opener = opener
self.after = after
self.entries = []
self.map = {}
self.journal = journal
self.file = open(self.journal, "w")
def __del__(self):
if self.entries: self.abort()
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:
os.rename(self.journal, self.after)
else:
os.unlink(self.journal)
def abort(self):
if not self.entries: return
print "transaction abort!"
for f, o in self.entries:
try:
self.opener(f, "a").truncate(o)
except:
print "failed to truncate", f
self.entries = []
print "rollback completed"
def rollback(opener, file):
for l in open(file).readlines():
f, o = l.split('\0')
opener(f, "a").truncate(int(o))
os.unlink(file)