view contrib/python3-ratchet.py @ 34880:9e18ab7f7240

sparse-read: move from a recursive-based approach to a heap-based one

The previous recursive approach was trying to optimise each read slice to have
a good density. It had the tendency to over-optimize smaller slices while
leaving larger hole in others.

The new approach focuses on improving the combined density of all the reads,
instead of the individual slices. It slices at the largest gaps first, as they
reduce the total amount of read data the most efficiently.

Another benefit of this approach is that we iterate over the delta chain only
once, reducing the overhead of slicing long delta chains.

On the repository we use for tests, the new approach shows similar or faster
performance than the current default linear full read.

The repository contains about 450,000 revisions with many concurrent
topological branches. Tests have been run on two versions of the repository:
one built with the current delta constraint, and the other with an unlimited
delta span (using 'experimental.maxdeltachainspan=0')

Below are timings for building 1% of all the revision in the manifest log using
'hg perfrevlogrevisions -m'. Times are given in seconds. They include the new
couple of follow-up changeset in this series.

delta-span  standard    unlimited
linear-read     922s         632s
sparse-read     814s         566s

# Copyright 2012 Facebook
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Find tests that newly pass under Python 3.

The approach is simple: we maintain a whitelist of Python 3 passing
tests in the repository, and periodically run all the /other/ tests
and look for new passes. Any newly passing tests get automatically
added to the whitelist.

You probably want to run it like this:

  $ cd tests
  $ python3 ../contrib/python3-ratchet.py \
  >   --working-tests=../contrib/python3-whitelist
"""
from __future__ import print_function
from __future__ import absolute_import

import argparse
import json
import os
import subprocess
import sys

_hgenv = dict(os.environ)
_hgenv.update({
    'HGPLAIN': '1',
    })

_HG_FIRST_CHANGE = '9117c6561b0bd7792fa13b50d28239d51b78e51f'

def _runhg(*args):
    return subprocess.check_output(args, env=_hgenv)

def _is_hg_repo(path):
    return _runhg('hg', 'log', '-R', path,
                  '-r0', '--template={node}').strip() == _HG_FIRST_CHANGE

def _py3default():
    if sys.version_info[0] >= 3:
        return sys.executable
    return 'python3'

def main(argv=()):
    p = argparse.ArgumentParser()
    p.add_argument('--working-tests',
                   help='List of tests that already work in Python 3.')
    p.add_argument('--commit-to-repo',
                   help='If set, commit newly fixed tests to the given repo')
    p.add_argument('-j', default=os.sysconf(r'SC_NPROCESSORS_ONLN'), type=int,
                   help='Number of parallel tests to run.')
    p.add_argument('--python3', default=_py3default(),
                   help='python3 interpreter to use for test run')
    p.add_argument('--commit-user',
                   default='[e-mail]',
                   help='Username to specify when committing to a repo.')
    opts = p.parse_args(argv)
    if opts.commit_to_repo:
        if not _is_hg_repo(opts.commit_to_repo):
            print('abort: specified repository is not the hg repository')
            sys.exit(1)
    if not opts.working_tests or not os.path.isfile(opts.working_tests):
        print('abort: --working-tests must exist and be a file (got %r)' %
              opts.working_tests)
        sys.exit(1)
    elif opts.commit_to_repo:
        root = _runhg('hg', 'root').strip()
        if not opts.working_tests.startswith(root):
            print('abort: if --commit-to-repo is given, '
                  '--working-tests must be from that repo')
            sys.exit(1)
    try:
        subprocess.check_call([opts.python3, '-c',
                               'import sys ; '
                               'assert ((3, 5) <= sys.version_info < (3, 6) '
                               'or sys.version_info >= (3, 6, 2))'])
    except subprocess.CalledProcessError:
        print('warning: Python 3.6.0 and 3.6.1 have '
              'a bug which breaks Mercurial')
        print('(see https://bugs.python.org/issue29714 for details)')
        # TODO(augie): uncomment exit when Python 3.6.2 is available
        # sys.exit(1)

    rt = subprocess.Popen([opts.python3, 'run-tests.py', '-j', str(opts.j),
                           '--blacklist', opts.working_tests, '--json'])
    rt.wait()
    with open('report.json') as f:
        data = f.read()
    report = json.loads(data.split('=', 1)[1])
    newpass = set()
    for test, result in report.items():
        if result['result'] != 'success':
            continue
        # A new passing test! Huzzah!
        newpass.add(test)
    if newpass:
        # We already validated the repo, so we can just dive right in
        # and commit.
        if opts.commit_to_repo:
            print(len(newpass), 'new passing tests on Python 3!')
            with open(opts.working_tests) as f:
                oldpass = {l for l in f.read().splitlines() if l}
            with open(opts.working_tests, 'w') as f:
                for p in sorted(oldpass | newpass):
                    f.write('%s\n' % p)
            _runhg('hg', 'commit', '-R', opts.commit_to_repo,
                   '--user', opts.commit_user,
                   '--message', 'python3: expand list of passing tests')
        else:
            print('Newly passing tests:', '\n'.join(sorted(newpass)))
            sys.exit(2)

if __name__ == '__main__':
    main(sys.argv[1:])