contrib/perf.py

rebase: allow for rebasing descendants onto ancestors on different named branches

So far we've been denying rebasing descendants onto ancestors, but there are
situations in which this kind of operation makes perfect sense to me.

Let's say we have made a commit (or more), that belongs to branch 'dev', on
top of the named branch 'stable':

... a (stable) - b (dev)

but then we realize that b should belong to branch 'stable'.
In these cases a rebase means: "move these csets from named branch A to named
branch B" and there isn't a valid reason to deny it.

This patch basically doesn't block it, if source and destination are
on different named branches.
The old behaviour still applies for rebases across the same named branch.

Can you think of any tricky corner cases in which this new behaviour could
lead to problems? (I bet there are tons of them...)

By the way, I created a brand new .t because I feel there should be more
tests I can't think of at the moment.

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

from mercurial import cmdutil, match, commands
import time, os, sys

def timer(func, title=None):
    results = []
    begin = time.time()
    count = 0
    while 1:
        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))

def perfwalk(ui, repo, *pats):
    try:
        m = cmdutil.match(repo, pats, {})
        timer(lambda: len(list(repo.dirstate.walk(m, [], True, False))))
    except:
        try:
            m = cmdutil.match(repo, pats, {})
            timer(lambda: len([b for a, b, c in repo.dirstate.statwalk([], m)]))
        except:
            timer(lambda: len(list(cmdutil.walk(repo, pats, {}))))

def perfstatus(ui, repo, *pats):
    #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())))

def perfheads(ui, repo):
    timer(lambda: len(repo.changelog.heads()))

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)

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

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

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)

def perfindex(ui, repo):
    import mercurial.revlog
    mercurial.revlog._prereadsize = 2**24 # disable lazy parser in old hg
    n = repo["tip"].node()
    def d():
        repo.invalidate()
        repo[n]
    timer(d)

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

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)

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

def perflog(ui, repo, **opts):
    ui.pushbuffer()
    timer(lambda: commands.log(ui, repo, rev=[], date='', user='',
                               copies=opts.get('rename')))
    ui.popbuffer()

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()

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)

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)

cmdtable = {
    'perflookup': (perflookup, []),
    'perfparents': (perfparents, []),
    'perfstartup': (perfstartup, []),
    'perfstatus': (perfstatus, []),
    'perfwalk': (perfwalk, []),
    'perfmanifest': (perfmanifest, []),
    'perfindex': (perfindex, []),
    'perfheads': (perfheads, []),
    'perftags': (perftags, []),
    'perfdirstate': (perfdirstate, []),
    'perfdirstatedirs': (perfdirstate, []),
    'perflog': (perflog,
                [('', 'rename', False, 'ask log to follow renames')]),
    'perftemplating': (perftemplating, []),
    'perfdiffwd': (perfdiffwd, []),
    'perfrevlog': (perfrevlog,
                   [('d', 'dist', 100, 'distance between the revisions')],
                   "[INDEXFILE]"),
}