view tests/test-filecache.py @ 46408:e948ad0dcbe2

copies: add an devel option to trace all files

Filelog based copy tracing only trace copy for file that have been added. This
is a trade off between skipping some rare copy case in exchange for avoiding
atrocious-to-the-point-of-unusable performance.

The changeset centric copy tracing does not need this trade off and naturally
trace all copy, include the one involving non-new files.

In order to ease the comparison from both algorithm, we add a small devel option
to trace copy for all files in the target revisions.

Differential Revision: https://phab.mercurial-scm.org/D9796

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

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

print_ = print


def print(*args, **kwargs):
    """print() wrapper that flushes stdout buffers to avoid py3 buffer issues

    We could also just write directly to sys.stdout.buffer the way the
    ui object will, but this was easier for porting the test.
    """
    print_(*args, **kwargs)
    sys.stdout.flush()


from mercurial import (
    extensions,
    hg,
    localrepo,
    pycompat,
    ui as uimod,
    util,
    vfs as vfsmod,
)

if pycompat.ispy3:
    xrange = range


class fakerepo(object):
    def __init__(self):
        self._filecache = {}

    class fakevfs(object):
        def join(self, p):
            return p

    vfs = fakevfs()

    def unfiltered(self):
        return self

    def sjoin(self, p):
        return p

    @localrepo.repofilecache('x', 'y')
    def cached(self):
        print('creating')
        return 'string from function'

    def invalidate(self):
        for k in self._filecache:
            try:
                delattr(self, pycompat.sysstr(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 = vfsmod.vfs(b'.')(b'x', b'w', atomictemp=True)
    f.write(b'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 = vfsmod.vfs(b'.')(b'y', b'w', atomictemp=True)
    f.write(b'B')
    f.close()

    repo.invalidate()
    print("* file y changed inode")
    repo.cached

    f = vfsmod.vfs(b'.')(b'x', b'w', atomictemp=True)
    f.write(b'c')
    f.close()
    f = vfsmod.vfs(b'.')(b'y', b'w', atomictemp=True)
    f.write(b'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.load())
    # first rollback clears the filecache, but changelog to stays in __dict__
    repo.rollback()
    repo.commit(b'.')
    # 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(b'.')


def setbeforeget(repo):
    os.remove('x')
    os.remove('y')
    repo.__class__.cached.set(repo, '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.__class__.cached.set(repo, '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)


def antiambiguity():
    filename = 'ambigcheck'

    # try some times, because reproduction of ambiguity depends on
    # "filesystem time"
    for i in xrange(5):
        fp = open(filename, 'w')
        fp.write('FOO')
        fp.close()

        oldstat = os.stat(filename)
        if oldstat[stat.ST_CTIME] != oldstat[stat.ST_MTIME]:
            # subsequent changing never causes ambiguity
            continue

        repetition = 3

        # repeat changing via checkambigatclosing, to examine whether
        # st_mtime is advanced multiple times as expected
        for i in xrange(repetition):
            # explicit closing
            fp = vfsmod.checkambigatclosing(open(filename, 'a'))
            fp.write('FOO')
            fp.close()

            # implicit closing by "with" statement
            with vfsmod.checkambigatclosing(open(filename, 'a')) as fp:
                fp.write('BAR')

        newstat = os.stat(filename)
        if oldstat[stat.ST_CTIME] != newstat[stat.ST_CTIME]:
            # timestamp ambiguity was naturally avoided while repetition
            continue

        # st_mtime should be advanced "repetition * 2" times, because
        # all changes occurred at same time (in sec)
        expected = (oldstat[stat.ST_MTIME] + repetition * 2) & 0x7FFFFFFF
        if newstat[stat.ST_MTIME] != expected:
            print(
                "'newstat[stat.ST_MTIME] %s is not %s (as %s + %s * 2)"
                % (
                    newstat[stat.ST_MTIME],
                    expected,
                    oldstat[stat.ST_MTIME],
                    repetition,
                )
            )

        # no more examination is needed regardless of result
        break
    else:
        # This platform seems too slow to examine anti-ambiguity
        # of file timestamp (or test happened to be executed at
        # bad timing). Exit silently in this case, because running
        # on other faster platforms can detect problems
        pass


print('basic:')
print()
basic(fakerepo())
print()
print('fakeuncacheable:')
print()
fakeuncacheable()
test_filecache_synced()
print()
print('setbeforeget:')
print()
setbeforeget(fakerepo())
print()
print('antiambiguity:')
print()
antiambiguity()