contrib/perf.py

largefiles: don't verify largefile hashes on servers when processing statlfile

When changesets referencing largefiles are pushed then the corresponding
largefiles will be pushed too - unless the target already has them. The client
will use statlfile to make sure it only sends largefiles that the target
doesn't have. The server would however on every statlfile check that the
content of the largefile had the expected hash. What should be cheap thus
became an expensive operation that trashed the disk and the cache.

Largefile hashes are already checked by putlfile before being stored on the
server. A server should thus be able to keep its largefile store free of
errors - even more than it can keep revlogs free of errors. Verification should
happen when running 'hg verify' locally on the server. Rehashing every
largefile on every remote stat is too expensive.

Clients will also stat lfiles before downloading them. When the server verified
the hash in stat it meant that it had to read the file twice to serve it.

With this change the server will assume its own hashes are ok without checking
them on every statlfile.

Some consequences of this change:
- in case of server side corruption the problem will be detected by the
  existing check on the client side - not on server side
- clients that could upload an uncorrupted largefile when pushing will no
  longer magically heal the server (and break hardlinks) - a client will now
  only upload its uncorrupted files after the corrupted file has been removed
  on the server side
- client side verify will no longer report corruption in files it doesn't have

(Issue3123 discussed related problems - and how they have been fixed.)

# perf.py - performance test routines
'''helper extension to measure performance'''

from mercurial import cmdutil, scmutil, util, match, commands, obsolete
from mercurial import repoview, branchmap
import time, os, sys

cmdtable = {}
command = cmdutil.command(cmdtable)

def timer(func, title=None):
    results = []
    begin = time.time()
    count = 0
    while True:
        ostart = os.times()
        cstart = time.time()
        r = func()
        cstop = time.time()
        ostop = os.times()
        count += 1
        a, b = ostart, ostop
        results.append((cstop - cstart, b[0] - a[0], b[1]-a[1]))
        if cstop - begin > 3 and count >= 100:
            break
        if cstop - begin > 10 and count >= 3:
            break
    if title:
        sys.stderr.write("! %s\n" % title)
    if r:
        sys.stderr.write("! result: %s\n" % r)
    m = min(results)
    sys.stderr.write("! wall %f comb %f user %f sys %f (best of %d)\n"
                     % (m[0], m[1] + m[2], m[1], m[2], count))

@command('perfwalk')
def perfwalk(ui, repo, *pats):
    try:
        m = scmutil.match(repo[None], pats, {})
        timer(lambda: len(list(repo.dirstate.walk(m, [], True, False))))
    except Exception:
        try:
            m = scmutil.match(repo[None], pats, {})
            timer(lambda: len([b for a, b, c in repo.dirstate.statwalk([], m)]))
        except Exception:
            timer(lambda: len(list(cmdutil.walk(repo, pats, {}))))

@command('perfstatus',
         [('u', 'unknown', False,
           'ask status to look for unknown files')])
def perfstatus(ui, repo, **opts):
    #m = match.always(repo.root, repo.getcwd())
    #timer(lambda: sum(map(len, repo.dirstate.status(m, [], False, False,
    #                                                False))))
    timer(lambda: sum(map(len, repo.status(**opts))))

def clearcaches(cl):
    # behave somewhat consistently across internal API changes
    if util.safehasattr(cl, 'clearcaches'):
        cl.clearcaches()
    elif util.safehasattr(cl, '_nodecache'):
        from mercurial.node import nullid, nullrev
        cl._nodecache = {nullid: nullrev}
        cl._nodepos = None

@command('perfheads')
def perfheads(ui, repo):
    cl = repo.changelog
    def d():
        len(cl.headrevs())
        clearcaches(cl)
    timer(d)

@command('perftags')
def perftags(ui, repo):
    import mercurial.changelog, mercurial.manifest
    def t():
        repo.changelog = mercurial.changelog.changelog(repo.sopener)
        repo.manifest = mercurial.manifest.manifest(repo.sopener)
        repo._tags = None
        return len(repo.tags())
    timer(t)

@command('perfancestors')
def perfancestors(ui, repo):
    heads = repo.changelog.headrevs()
    def d():
        for a in repo.changelog.ancestors(heads):
            pass
    timer(d)

@command('perfancestorset')
def perfancestorset(ui, repo, revset):
    revs = repo.revs(revset)
    heads = repo.changelog.headrevs()
    def d():
        s = repo.changelog.ancestors(heads)
        for rev in revs:
            rev in s
    timer(d)

@command('perfdirstate')
def perfdirstate(ui, repo):
    "a" in repo.dirstate
    def d():
        repo.dirstate.invalidate()
        "a" in repo.dirstate
    timer(d)

@command('perfdirstatedirs')
def perfdirstatedirs(ui, repo):
    "a" in repo.dirstate
    def d():
        "a" in repo.dirstate._dirs
        del repo.dirstate._dirs
    timer(d)

@command('perfdirstatewrite')
def perfdirstatewrite(ui, repo):
    ds = repo.dirstate
    "a" in ds
    def d():
        ds._dirty = True
        ds.write()
    timer(d)

@command('perfmanifest')
def perfmanifest(ui, repo):
    def d():
        t = repo.manifest.tip()
        m = repo.manifest.read(t)
        repo.manifest.mapcache = None
        repo.manifest._cache = None
    timer(d)

@command('perfchangeset')
def perfchangeset(ui, repo, rev):
    n = repo[rev].node()
    def d():
        c = repo.changelog.read(n)
        #repo.changelog._cache = None
    timer(d)

@command('perfindex')
def perfindex(ui, repo):
    import mercurial.revlog
    mercurial.revlog._prereadsize = 2**24 # disable lazy parser in old hg
    n = repo["tip"].node()
    def d():
        cl = mercurial.revlog.revlog(repo.sopener, "00changelog.i")
        cl.rev(n)
    timer(d)

@command('perfstartup')
def perfstartup(ui, repo):
    cmd = sys.argv[0]
    def d():
        os.system("HGRCPATH= %s version -q > /dev/null" % cmd)
    timer(d)

@command('perfparents')
def perfparents(ui, repo):
    nl = [repo.changelog.node(i) for i in xrange(1000)]
    def d():
        for n in nl:
            repo.changelog.parents(n)
    timer(d)

@command('perflookup')
def perflookup(ui, repo, rev):
    timer(lambda: len(repo.lookup(rev)))

@command('perfrevrange')
def perfrevrange(ui, repo, *specs):
    revrange = scmutil.revrange
    timer(lambda: len(revrange(repo, specs)))

@command('perfnodelookup')
def perfnodelookup(ui, repo, rev):
    import mercurial.revlog
    mercurial.revlog._prereadsize = 2**24 # disable lazy parser in old hg
    n = repo[rev].node()
    cl = mercurial.revlog.revlog(repo.sopener, "00changelog.i")
    def d():
        cl.rev(n)
        clearcaches(cl)
    timer(d)

@command('perflog',
         [('', 'rename', False, 'ask log to follow renames')])
def perflog(ui, repo, **opts):
    ui.pushbuffer()
    timer(lambda: commands.log(ui, repo, rev=[], date='', user='',
                               copies=opts.get('rename')))
    ui.popbuffer()

@command('perftemplating')
def perftemplating(ui, repo):
    ui.pushbuffer()
    timer(lambda: commands.log(ui, repo, rev=[], date='', user='',
                               template='{date|shortdate} [{rev}:{node|short}]'
                               ' {author|person}: {desc|firstline}\n'))
    ui.popbuffer()

@command('perfcca')
def perfcca(ui, repo):
    timer(lambda: scmutil.casecollisionauditor(ui, False, repo.dirstate))

@command('perffncacheload')
def perffncacheload(ui, repo):
    s = repo.store
    def d():
        s.fncache._load()
    timer(d)

@command('perffncachewrite')
def perffncachewrite(ui, repo):
    s = repo.store
    s.fncache._load()
    def d():
        s.fncache._dirty = True
        s.fncache.write()
    timer(d)

@command('perffncacheencode')
def perffncacheencode(ui, repo):
    s = repo.store
    s.fncache._load()
    def d():
        for p in s.fncache.entries:
            s.encode(p)
    timer(d)

@command('perfdiffwd')
def perfdiffwd(ui, repo):
    """Profile diff of working directory changes"""
    options = {
        'w': 'ignore_all_space',
        'b': 'ignore_space_change',
        'B': 'ignore_blank_lines',
        }

    for diffopt in ('', 'w', 'b', 'B', 'wB'):
        opts = dict((options[c], '1') for c in diffopt)
        def d():
            ui.pushbuffer()
            commands.diff(ui, repo, **opts)
            ui.popbuffer()
        title = 'diffopts: %s' % (diffopt and ('-' + diffopt) or 'none')
        timer(d, title)

@command('perfrevlog',
         [('d', 'dist', 100, 'distance between the revisions')],
         "[INDEXFILE]")
def perfrevlog(ui, repo, file_, **opts):
    from mercurial import revlog
    dist = opts['dist']
    def d():
        r = revlog.revlog(lambda fn: open(fn, 'rb'), file_)
        for x in xrange(0, len(r), dist):
            r.revision(r.node(x))

    timer(d)

@command('perfrevset',
         [('C', 'clear', False, 'clear volatile cache between each call.')],
         "REVSET")
def perfrevset(ui, repo, expr, clear=False):
    """benchmark the execution time of a revset

    Use the --clean option if need to evaluate the impact of build volative
    revisions set cache on the revset execution. Volatile cache hold filtered
    and obsolete related cache."""
    def d():
        if clear:
            repo.invalidatevolatilesets()
        repo.revs(expr)
    timer(d)

@command('perfvolatilesets')
def perfvolatilesets(ui, repo, *names):
    """benchmark the computation of various volatile set

    Volatile set computes element related to filtering and obsolescence."""
    repo = repo.unfiltered()

    def getobs(name):
        def d():
            repo.invalidatevolatilesets()
            obsolete.getrevs(repo, name)
        return d

    allobs = sorted(obsolete.cachefuncs)
    if names:
        allobs = [n for n in allobs if n in names]

    for name in allobs:
        timer(getobs(name), title=name)

    def getfiltered(name):
        def d():
            repo.invalidatevolatilesets()
            repoview.filteredrevs(repo, name)
        return d

    allfilter = sorted(repoview.filtertable)
    if names:
        allfilter = [n for n in allfilter if n in names]

    for name in allfilter:
        timer(getfiltered(name), title=name)

@command('perfbranchmap',
         [('f', 'full', False,
           'Includes build time of subset'),
         ])
def perfbranchmap(ui, repo, full=False):
    """benchmark the update of a branchmap

    This benchmarks the full repo.branchmap() call with read and write disabled
    """
    def getbranchmap(filtername):
        """generate a benchmark function for the filtername"""
        if filtername is None:
            view = repo
        else:
            view = repo.filtered(filtername)
        def d():
            if full:
                view._branchcaches.clear()
            else:
                view._branchcaches.pop(filtername, None)
            view.branchmap()
        return d
    # add filter in smaller subset to bigger subset
    possiblefilters = set(repoview.filtertable)
    allfilters = []
    while possiblefilters:
        for name in possiblefilters:
            subset = repoview.subsettable.get(name)
            if subset not in possiblefilters:
                break
        else:
            assert False, 'subset cycle %s!' % possiblefilters
        allfilters.append(name)
        possiblefilters.remove(name)

    # warm the cache
    if not full:
        for name in allfilters:
            repo.filtered(name).branchmap()
    # add unfiltered
    allfilters.append(None)
    oldread = branchmap.read
    oldwrite = branchmap.branchcache.write
    try:
        branchmap.read = lambda repo: None
        branchmap.write = lambda repo: None
        for name in allfilters:
            timer(getbranchmap(name), title=str(name))
    finally:
        branchmap.read = oldread
        branchmap.branchcache.write = oldwrite