view tests/test-ctxmanager.py @ 27784:432242f41d9f

obsolete: make _computeobsoleteset much faster

This patch makes _computeobsoleteset much faster by looping
over the draft and secrets as opposed to looping over the
successors.
This works because "number of draft and secret" is typically
way smaller(<100) than the number of successor in the repo (~90k in
my checkout of core mercurial as of today). And also because
it is very fast to compute "not public()".

I timed the code with the following setup:
"""
from mercurial import hg, ui, obsolete
ui = ui.ui()
repo = hg.repository(ui, "~/hg")
l = repo.obsstore.successors # This caches the result
"""

With about 90k successors.

k=obsolete._computeobsoleteset(repo) before this patch:
10 loops, best of 3: 33.9 ms per loop

k=obsolete._computeobsoleteset(repo) after this patch:
10000 loops, best of 3: 83.3 µs per loop

from __future__ import absolute_import

import silenttestrunner
import unittest

from mercurial.util import ctxmanager

class contextmanager(object):
    def __init__(self, name, trace):
        self.name = name
        self.entered = False
        self.exited = False
        self.trace = trace

    def __enter__(self):
        self.entered = True
        self.trace(('enter', self.name))
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.exited = exc_type, exc_val, exc_tb
        self.trace(('exit', self.name))

    def __repr__(self):
        return '<ctx %r>' % self.name

class ctxerror(Exception):
    pass

class raise_on_enter(contextmanager):
    def __enter__(self):
        self.trace(('raise', self.name))
        raise ctxerror(self.name)

class raise_on_exit(contextmanager):
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.trace(('raise', self.name))
        raise ctxerror(self.name)

def ctxmgr(name, trace):
    return lambda: contextmanager(name, trace)

class test_ctxmanager(unittest.TestCase):
    def test_basics(self):
        trace = []
        addtrace = trace.append
        with ctxmanager(ctxmgr('a', addtrace), ctxmgr('b', addtrace)) as c:
            a, b = c()
            c.atexit(addtrace, ('atexit', 'x'))
            c.atexit(addtrace, ('atexit', 'y'))
        self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'),
                                 ('atexit', 'y'), ('atexit', 'x'),
                                 ('exit', 'b'), ('exit', 'a')])

    def test_raise_on_enter(self):
        trace = []
        addtrace = trace.append
        with self.assertRaises(ctxerror):
            with ctxmanager(ctxmgr('a', addtrace),
                           lambda: raise_on_enter('b', addtrace)) as c:
                c()
                addtrace('unreachable')
        self.assertEqual(trace, [('enter', 'a'), ('raise', 'b'), ('exit', 'a')])

    def test_raise_on_exit(self):
        trace = []
        addtrace = trace.append
        with self.assertRaises(ctxerror):
            with ctxmanager(ctxmgr('a', addtrace),
                           lambda: raise_on_exit('b', addtrace)) as c:
                c()
                addtrace('running')
        self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'), 'running',
                                 ('raise', 'b'), ('exit', 'a')])

if __name__ == '__main__':
    silenttestrunner.main(__name__)