exchange: make clone bundles non-experimental and enabled by default
The clone bundles feature was introduced in Mercurial 3.6 behind an
experimental and disabled by default flag. The feature has been enabled
on hg.mozilla.org for a few months and has served many terabytes of
clones. Users have been encouraged to use the feature and reception
has been very positive (mainly due to faster clones as a result of
connecting to a CDN). I have heard no feedback about changing the
feature other than inquiries about when it will be enabled by default.
So, I think the feature is ready to be enabled by default.
This patch renames experimental.clonebundles to ui.clonebundles,
documents the option, and enables it by default. References to the
experimental state of clone bundles have been removed. The remaining
config option docs in clonebundles.py have been removed because they
are redudant with `hg help config`.
There are some oddities with behavior of clone bundles. Because clones
with clone bundles are effectively 2 `hg pull` operations, there may be
2 transactions. This could result in hooks running twice. If the
subsequent pull is aborted, it could result in partial rollback and an
incomplete clone. This behavior is a bit wonky and should probably
be documented. If this patch is accepted, I'll send a follow-up to
document it. I don't think this behavior should prevent the feature
being enabled by default. Reworking the clone mechanism to support
interrupted or multi-part clones feels like a major new feature and
something that when implemented can change the hook and rollback
semantics of clone bundles. Besides, partial clone is better than
full rollback and hooks running on initial clone are likely rare, so I
think the impact is minimal.
from __future__ import absolute_import
import silenttestrunner
import unittest
from mercurial.util import ctxmanager
class contextmanager(object):
def __init__(self, name, trace):
self.name = name
self.entered = False
self.exited = False
self.trace = trace
def __enter__(self):
self.entered = True
self.trace(('enter', self.name))
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.exited = exc_type, exc_val, exc_tb
self.trace(('exit', self.name))
def __repr__(self):
return '<ctx %r>' % self.name
class ctxerror(Exception):
pass
class raise_on_enter(contextmanager):
def __enter__(self):
self.trace(('raise', self.name))
raise ctxerror(self.name)
class raise_on_exit(contextmanager):
def __exit__(self, exc_type, exc_val, exc_tb):
self.trace(('raise', self.name))
raise ctxerror(self.name)
def ctxmgr(name, trace):
return lambda: contextmanager(name, trace)
class test_ctxmanager(unittest.TestCase):
def test_basics(self):
trace = []
addtrace = trace.append
with ctxmanager(ctxmgr('a', addtrace), ctxmgr('b', addtrace)) as c:
a, b = c()
c.atexit(addtrace, ('atexit', 'x'))
c.atexit(addtrace, ('atexit', 'y'))
self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'),
('atexit', 'y'), ('atexit', 'x'),
('exit', 'b'), ('exit', 'a')])
def test_raise_on_enter(self):
trace = []
addtrace = trace.append
with self.assertRaises(ctxerror):
with ctxmanager(ctxmgr('a', addtrace),
lambda: raise_on_enter('b', addtrace)) as c:
c()
addtrace('unreachable')
self.assertEqual(trace, [('enter', 'a'), ('raise', 'b'), ('exit', 'a')])
def test_raise_on_exit(self):
trace = []
addtrace = trace.append
with self.assertRaises(ctxerror):
with ctxmanager(ctxmgr('a', addtrace),
lambda: raise_on_exit('b', addtrace)) as c:
c()
addtrace('running')
self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'), 'running',
('raise', 'b'), ('exit', 'a')])
if __name__ == '__main__':
silenttestrunner.main(__name__)