atomictempfile: make close() consistent with other file-like objects.
The usual contract is that close() makes your writes permanent, so
atomictempfile's use of close() to *discard* writes (and rename() to
keep them) is rather unexpected. Thus, change it so close() makes
things permanent and add a new discard() method to throw them away.
discard() is only used internally, in __del__(), to ensure that writes
are discarded when an atomictempfile object goes out of scope.
I audited mercurial.*, hgext.*, and ~80 third-party extensions, and
found no one using the existing semantics of close() to discard
writes, so this should be safe.
import sys, os, subprocess
if subprocess.call(['%s/hghave' % os.environ['TESTDIR'], 'cacheable']):
sys.exit(80)
from mercurial import util, scmutil, extensions
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')
def cached(self):
print 'creating'
def invalidate(self):
for k in self._filecache:
try:
delattr(self, k)
except AttributeError:
pass
def basic(repo):
# file doesn't exist, calls function
repo.cached
repo.invalidate()
# file still doesn't exist, uses cache
repo.cached
# create empty file
f = open('x', 'w')
f.close()
repo.invalidate()
# should recreate the object
repo.cached
f = open('x', 'w')
f.write('a')
f.close()
repo.invalidate()
# should recreate the object
repo.cached
repo.invalidate()
# stats file again, nothing changed, 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()
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)
try:
os.remove('x')
except:
pass
basic(fakerepo())
util.cachestat.cacheable = origcacheable
util.cachestat.__init__ = originit
print 'basic:'
print
basic(fakerepo())
print
print 'fakeuncacheable:'
print
fakeuncacheable()