view tests/test-filecache.py @ 29917:f32f8bf5dc4c

streamclone: force @filecache properties to be reloaded from file

Before this patch, consumev1() invokes repo.invalidate() after closing
transaction, to force @filecache properties to be reloaded from files
at next access, because streamclone writes data into files directly.

But this doesn't work as expected in the case below:

  1. at closing transaction, repo._refreshfilecachestats() refreshes
     file stat of each @filecache properties with streamclone-ed files

     This means that in-memory properties are treated as valid.

  2. but streamclone doesn't changes in-memory properties

     This means that in-memory properties are actually invalid.

  3. repo.invalidate() just forces to examine file stat of @filecache
     properties at the first access after it

     Such examination should concludes that reloading from file isn't
     needed, because file stat was already refreshed at (1).

     Therefore, invalid in-memory cached properties (2) are
     unintentionally treated as valid (1).

This patch invokes repo.invalidate() with clearfilecache=True, to
force @filecache properties to be reloaded from file at next access.

BTW, it is accidental that repo.invalidate() without
clearfilecache=True in streamclone case seems to work as expected
before this patch.

If transaction is started via "filtered repo" object,
repo._refreshfilecachestats() tries to refresh file stat of each
@filecache properties on "filtered repo" object, even though all of
them are stored into "unfiltered repo" object.

In this case, repo._refreshfilecachestats() does nothing
unintentionally, but this unexpected behavior causes reloading
@filecache properties after repo.invalidate().

This is reason why this patch should be applied before making
_refreshfilecachestats() correctly refresh file stat of @filecache
properties.

from __future__ import absolute_import, print_function
import os
import subprocess
import sys

if subprocess.call(['python', '%s/hghave' % os.environ['TESTDIR'],
                    'cacheable']):
    sys.exit(80)

from mercurial import (
    extensions,
    hg,
    scmutil,
    ui as uimod,
    util,
)

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 behavior that caused filecached properties to go out of sync
    os.system('hg init && echo a >> a && hg ci -qAm.')
    repo = hg.repository(uimod.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())