fncache: move fncache writing to be in a transaction
Previously the fncache was written at lock.release time. This meant it was not
tracked by a transaction, and if an error occurred during the fncache write it
would fail to update the fncache, but would not rollback the transaction,
resulting in an fncache that was not in sync with the files on disk (which
causes verify to fail, and causes streaming clones to not copy all the revlogs).
This uses the new transaction backup mechanism to make the fncache transacted.
It also moves the fncache from being written at lock.release time, to being
written at transaction.close time.
import sys, os, subprocess
if subprocess.call(['python', '%s/hghave' % os.environ['TESTDIR'],
'cacheable']):
sys.exit(80)
from mercurial import util, scmutil, extensions, hg, ui
filecache = scmutil.filecache
class fakerepo(object):
def __init__(self):
self._filecache = {}
def join(self, p):
return p
def sjoin(self, p):
return p
@filecache('x', 'y')
def cached(self):
print 'creating'
return 'string from function'
def invalidate(self):
for k in self._filecache:
try:
delattr(self, k)
except AttributeError:
pass
def basic(repo):
print "* neither file exists"
# calls function
repo.cached
repo.invalidate()
print "* neither file still exists"
# uses cache
repo.cached
# create empty file
f = open('x', 'w')
f.close()
repo.invalidate()
print "* empty file x created"
# should recreate the object
repo.cached
f = open('x', 'w')
f.write('a')
f.close()
repo.invalidate()
print "* file x changed size"
# should recreate the object
repo.cached
repo.invalidate()
print "* nothing changed with either file"
# stats file again, reuses object
repo.cached
# atomic replace file, size doesn't change
# hopefully st_mtime doesn't change as well so this doesn't use the cache
# because of inode change
f = scmutil.opener('.')('x', 'w', atomictemp=True)
f.write('b')
f.close()
repo.invalidate()
print "* file x changed inode"
repo.cached
# create empty file y
f = open('y', 'w')
f.close()
repo.invalidate()
print "* empty file y created"
# should recreate the object
repo.cached
f = open('y', 'w')
f.write('A')
f.close()
repo.invalidate()
print "* file y changed size"
# should recreate the object
repo.cached
f = scmutil.opener('.')('y', 'w', atomictemp=True)
f.write('B')
f.close()
repo.invalidate()
print "* file y changed inode"
repo.cached
f = scmutil.opener('.')('x', 'w', atomictemp=True)
f.write('c')
f.close()
f = scmutil.opener('.')('y', 'w', atomictemp=True)
f.write('C')
f.close()
repo.invalidate()
print "* both files changed inode"
repo.cached
def fakeuncacheable():
def wrapcacheable(orig, *args, **kwargs):
return False
def wrapinit(orig, *args, **kwargs):
pass
originit = extensions.wrapfunction(util.cachestat, '__init__', wrapinit)
origcacheable = extensions.wrapfunction(util.cachestat, 'cacheable',
wrapcacheable)
for fn in ['x', 'y']:
try:
os.remove(fn)
except OSError:
pass
basic(fakerepo())
util.cachestat.cacheable = origcacheable
util.cachestat.__init__ = originit
def test_filecache_synced():
# test old behaviour that caused filecached properties to go out of sync
os.system('hg init && echo a >> a && hg ci -qAm.')
repo = hg.repository(ui.ui())
# first rollback clears the filecache, but changelog to stays in __dict__
repo.rollback()
repo.commit('.')
# second rollback comes along and touches the changelog externally
# (file is moved)
repo.rollback()
# but since changelog isn't under the filecache control anymore, we don't
# see that it changed, and return the old changelog without reconstructing
# it
repo.commit('.')
def setbeforeget(repo):
os.remove('x')
os.remove('y')
repo.cached = 'string set externally'
repo.invalidate()
print "* neither file exists"
print repo.cached
repo.invalidate()
f = open('x', 'w')
f.write('a')
f.close()
print "* file x created"
print repo.cached
repo.cached = 'string 2 set externally'
repo.invalidate()
print "* string set externally again"
print repo.cached
repo.invalidate()
f = open('y', 'w')
f.write('b')
f.close()
print "* file y created"
print repo.cached
print 'basic:'
print
basic(fakerepo())
print
print 'fakeuncacheable:'
print
fakeuncacheable()
test_filecache_synced()
print
print 'setbeforeget:'
print
setbeforeget(fakerepo())