Mercurial > hg
view tests/test-filecache.py @ 31467:08ecec297521
bdiff: use Python memory allocator in fixws
Python has its own memory allocation APIs. For allocations
<= 512 bytes, it allocates memory from arenas. This means that
average small allocations don't call the system allocator, which
makes them faster. Also, arena allocations cut down on memory
fragmentation, which can matter for performance in long-running
processes.
Another advantage of using the Python memory allocator is that
allocations are tracked by Python. This is a bigger deal in
Python 3, as modern versions of Python have some decent built-in
tools for examining memory usage, leaks, etc.
This patch converts a trivial malloc() + free() in the bdiff code
to use the Python allocator APIs. Since the object being
operated on is a line, chances are it will use an arena. So,
this could have a net positive impact on performance (although
I didn't measure it).
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 09 Mar 2017 11:54:25 -0800 |
parents | 74cbbd5420ba |
children | daa5f47558cf |
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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, localrepo, ui as uimod, util, vfs as vfsmod, ) 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, 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('.')('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 = vfsmod.vfs('.')('y', 'w', atomictemp=True) f.write('B') f.close() repo.invalidate() print("* file y changed inode") repo.cached f = vfsmod.vfs('.')('x', 'w', atomictemp=True) f.write('c') f.close() f = vfsmod.vfs('.')('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.load()) # 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) 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.st_ctime != oldstat.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.st_ctime != newstat.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.st_mtime + repetition * 2) & 0x7fffffff if newstat.st_mtime != expected: print("'newstat.st_mtime %s is not %s (as %s + %s * 2)" % (newstat.st_mtime, expected, oldstat.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()