##// END OF EJS Templates
hg: obtain lock when creating share from pooled repo (issue5104)...
hg: obtain lock when creating share from pooled repo (issue5104) There are race conditions between clients performing a shared clone to pooled storage: 1) Clients race to create the new shared repo in the pool directory 2) 1 client is seeding the repo in the pool directory and another goes to share it before it is fully cloned We prevent these race conditions by obtaining a lock in the pool directory that is derived from the name of the repo we will be accessing. To test this, a simple generic "lockdelay" extension has been added. The extension inserts an optional, configurable delay before or after lock acquisition. In the test, we delay 2 seconds after lock acquisition in the first process and 1 second before lock acquisition in the 2nd process. This means the first process has 1s to obtain the lock. There is a race condition here. If we encounter it in the wild, we could change the dummy extension to wait on the lock file to appear instead of relying on timing. But that's more complicated. Let's see what happens first.

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r27982:bf1d5c22 default
r28289:d493d647 3.7.2 stable
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schemes.py
108 lines | 3.5 KiB | text/x-python | PythonLexer
# Copyright 2009, Alexander Solovyov <piranha@piranha.org.ua>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""extend schemes with shortcuts to repository swarms
This extension allows you to specify shortcuts for parent URLs with a
lot of repositories to act like a scheme, for example::
[schemes]
py = http://code.python.org/hg/
After that you can use it like::
hg clone py://trunk/
Additionally there is support for some more complex schemas, for
example used by Google Code::
[schemes]
gcode = http://{1}.googlecode.com/hg/
The syntax is taken from Mercurial templates, and you have unlimited
number of variables, starting with ``{1}`` and continuing with
``{2}``, ``{3}`` and so on. This variables will receive parts of URL
supplied, split by ``/``. Anything not specified as ``{part}`` will be
just appended to an URL.
For convenience, the extension adds these schemes by default::
[schemes]
py = http://hg.python.org/
bb = https://bitbucket.org/
bb+ssh = ssh://hg@bitbucket.org/
gcode = https://{1}.googlecode.com/hg/
kiln = https://{1}.kilnhg.com/Repo/
You can override a predefined scheme by defining a new scheme with the
same name.
"""
import os, re
from mercurial import extensions, hg, templater, util, error
from mercurial.i18n import _
# Note for extension authors: ONLY specify testedwith = 'internal' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'internal'
class ShortRepository(object):
def __init__(self, url, scheme, templater):
self.scheme = scheme
self.templater = templater
self.url = url
try:
self.parts = max(map(int, re.findall(r'\{(\d+)\}', self.url)))
except ValueError:
self.parts = 0
def __repr__(self):
return '<ShortRepository: %s>' % self.scheme
def instance(self, ui, url, create):
# Should this use the util.url class, or is manual parsing better?
try:
url = url.split('://', 1)[1]
except IndexError:
raise error.Abort(_("no '://' in scheme url '%s'") % url)
parts = url.split('/', self.parts)
if len(parts) > self.parts:
tail = parts[-1]
parts = parts[:-1]
else:
tail = ''
context = dict((str(i + 1), v) for i, v in enumerate(parts))
url = ''.join(self.templater.process(self.url, context)) + tail
return hg._peerlookup(url).instance(ui, url, create)
def hasdriveletter(orig, path):
if path:
for scheme in schemes:
if path.startswith(scheme + ':'):
return False
return orig(path)
schemes = {
'py': 'http://hg.python.org/',
'bb': 'https://bitbucket.org/',
'bb+ssh': 'ssh://hg@bitbucket.org/',
'gcode': 'https://{1}.googlecode.com/hg/',
'kiln': 'https://{1}.kilnhg.com/Repo/'
}
def extsetup(ui):
schemes.update(dict(ui.configitems('schemes')))
t = templater.engine(lambda x: x)
for scheme, url in schemes.items():
if (os.name == 'nt' and len(scheme) == 1 and scheme.isalpha()
and os.path.exists('%s:\\' % scheme)):
raise error.Abort(_('custom scheme %s:// conflicts with drive '
'letter %s:\\\n') % (scheme, scheme.upper()))
hg.schemes[scheme] = ShortRepository(url, scheme, t)
extensions.wrapfunction(util, 'hasdriveletter', hasdriveletter)