view tests/test-propertycache.py @ 33289:abd7dedbaa36

sparse: vendor Facebook-developed extension

Facebook has developed an extension to enable "sparse" checkouts -
a working directory with a subset of files. This feature is a critical
component in enabling repositories to scale to infinite number of
files while retaining reasonable performance. It's worth noting
that sparse checkout is only one possible solution to this problem:
another is virtual filesystems that realize files on first access.
But given that virtual filesystems may not be accessible to all
users, sparse checkout is necessary as a fallback.

Per mailing list discussion at
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095868.html
we want to add sparse checkout to the Mercurial distribution via
roughly the following mechanism:

1. Vendor extension as-is with minimal modifications (this patch)
2. Refactor extension so it is more clearly experimental and inline
   with Mercurial practices
3. Move code from extension into core where possible
4. Drop experimental labeling and/or move feature into core
   after sign-off from narrow clone feature owners

This commit essentially copies the sparse extension and tests
from revision 71e0a2aeca92a4078fe1b8c76e32c88ff1929737 of the
https://bitbucket.org/facebook/hg-experimental repository.

A list of modifications made as part of vendoring is as follows:

* "EXPERIMENTAL" added to module docstring
* Imports were changed to match Mercurial style conventions
* "testedwith" value was updated to core Mercurial special value and
  comment boilerplate was inserted
* A "clone_sparse" function was renamed to "clonesparse" to appease
  the style checker
* Paths to the sparse extension in tests reflect built-in location
* test-sparse-extensions.t was renamed to test-sparse-fsmonitor.t
  and references to "simplecache" were removed. The test always skips
  because it isn't trivial to run it given the way we currently run
  fsmonitor tests
* A double empty line was removed from test-sparse-profiles.t

There are aspects of the added code that are obviously not ideal.
The goal is to make a minimal number of modifications as part of
the vendoring to make it easier to track changes from the original
implementation. Refactoring will occur in subsequent patches.

"""test behavior of propertycache and unfiltered propertycache

The repoview overlay is quite complex. We test the behavior of
property cache of both localrepo and repoview to prevent
regression."""

from __future__ import absolute_import, print_function
import os
import subprocess

from mercurial import (
    hg,
    localrepo,
    ui as uimod,
    util,
)

# create some special property cache that trace they call

calllog = []
@util.propertycache
def testcachedfoobar(repo):
    name = repo.filtername
    if name is None:
        name = ''
    val = len(name)
    calllog.append(val)
    return val

unficalllog = []
@localrepo.unfilteredpropertycache
def testcachedunfifoobar(repo):
    name = repo.filtername
    if name is None:
        name = ''
    val = 100 + len(name)
    unficalllog.append(val)
    return val

#plug them on repo
localrepo.localrepository.testcachedfoobar = testcachedfoobar
localrepo.localrepository.testcachedunfifoobar = testcachedunfifoobar


# Create an empty repo and instantiate it. It is important to run
# these tests on the real object to detect regression.
repopath = os.path.join(os.environ['TESTTMP'], 'repo')
assert subprocess.call(['hg', 'init', repopath]) == 0
ui = uimod.ui.load()
repo = hg.repository(ui, path=repopath).unfiltered()


print('')
print('=== property cache ===')
print('')
print('calllog:', calllog)
print('cached value (unfiltered):',
    vars(repo).get('testcachedfoobar', 'NOCACHE'))

print('')
print('= first access on unfiltered, should do a call')
print('access:', repo.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
    vars(repo).get('testcachedfoobar', 'NOCACHE'))

print('')
print('= second access on unfiltered, should not do call')
print('access', repo.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
    vars(repo).get('testcachedfoobar', 'NOCACHE'))

print('')
print('= first access on "visible" view, should do a call')
visibleview = repo.filtered('visible')
print('cached value ("visible" view):',
    vars(visibleview).get('testcachedfoobar', 'NOCACHE'))
print('access:', visibleview.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
    vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("visible" view):',
    vars(visibleview).get('testcachedfoobar', 'NOCACHE'))

print('')
print('= second access on "visible view", should not do call')
print('access:', visibleview.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
    vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("visible" view):',
    vars(visibleview).get('testcachedfoobar', 'NOCACHE'))

print('')
print('= no effect on other view')
immutableview = repo.filtered('immutable')
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedfoobar', 'NOCACHE'))
print('access:', immutableview.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
    vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("visible" view):',
    vars(visibleview).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedfoobar', 'NOCACHE'))

# unfiltered property cache test
print('')
print('')
print('=== unfiltered property cache ===')
print('')
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view):  ',
    vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))

print('')
print('= first access on unfiltered, should do a call')
print('access (unfiltered):', repo.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))

print('')
print('= second access on unfiltered, should not do call')
print('access (unfiltered):', repo.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))

print('')
print('= access on view should use the unfiltered cache')
print('access (unfiltered):      ', repo.testcachedunfifoobar)
print('access ("visible" view):  ', visibleview.testcachedunfifoobar)
print('access ("immutable" view):', immutableview.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view):  ',
    vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))

print('')
print('= even if we clear the unfiltered cache')
del repo.__dict__['testcachedunfifoobar']
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view):  ',
    vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('unficalllog:', unficalllog)
print('access ("visible" view):  ', visibleview.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view):  ',
    vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('access ("immutable" view):', immutableview.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view):  ',
    vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('access (unfiltered):      ', repo.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered):      ',
    vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view):  ',
    vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
    vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))