view contrib/benchmarks/__init__.py @ 40056:324b4b10351e

revlog: rewrite censoring logic

I was able to corrupt a revlog relatively easily with the existing
censoring code. The underlying problem is that the existing code
doesn't fully take delta chains into account. When copying revisions
that occur after the censored revision, the delta base can refer
to a censored revision. Then at read time, things blow up due to the
revision data not being a compressed delta.

This commit rewrites the revlog censoring code to take a higher-level
approach. We now create a new revlog instance pointing at temp files.
We iterate through each revision in the source revlog and insert
those revisions into the new revlog, replacing the censored revision's
data along the way.

The new implementation isn't as efficient as the old one. This is
because it will fully engage delta computation on insertion. But I
don't think it matters.

The new implementation is a bit hacky because it attempts to reload
the revlog instance with a new revlog index/data file. This is fragile.
But this is needed because the index (which could be backed by C) would
have a cached copy of the old, possibly changed data and that could
lead to problems accessing index or revision data later.

One benefit of the new approach is that we integrate with the
transaction. The old revlog is backed up and if the transaction is
rolled back, the original revlog is restored.

As part of this, we had to teach the transaction about the store
vfs. I'm not super keen about this. But this was the easiest way
to hook things up to the transaction. We /could/ just ignore the
transaction like we were doing before. But any file mutation should
be governed by transaction semantics, including undo during rollback.

Differential Revision: https://phab.mercurial-scm.org/D4869

# __init__.py - asv benchmark suite
#
# Copyright 2016 Logilab SA <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

# "historical portability" policy of contrib/benchmarks:
#
# We have to make this code work correctly with current mercurial stable branch
# and if possible with reasonable cost with early Mercurial versions.

'''ASV (https://asv.readthedocs.io) benchmark suite

Benchmark are parameterized against reference repositories found in the
directory pointed by the REPOS_DIR environment variable.

Invocation example:

    $ export REPOS_DIR=~/hgperf/repos
    # run suite on given revision
    $ asv --config contrib/asv.conf.json run REV
    # run suite on new changesets found in stable and default branch
    $ asv --config contrib/asv.conf.json run NEW
    # display a comparative result table of benchmark results between two given
    # revisions
    $ asv --config contrib/asv.conf.json compare REV1 REV2
    # compute regression detection and generate ASV static website
    $ asv --config contrib/asv.conf.json publish
    # serve the static website
    $ asv --config contrib/asv.conf.json preview
'''

from __future__ import absolute_import

import functools
import os
import re

from mercurial import (
    extensions,
    hg,
    ui as uimod,
    util,
)

basedir = os.path.abspath(os.path.join(os.path.dirname(__file__),
                          os.path.pardir, os.path.pardir))
reposdir = os.environ['REPOS_DIR']
reposnames = [name for name in os.listdir(reposdir)
              if os.path.isdir(os.path.join(reposdir, name, ".hg"))]
if not reposnames:
    raise ValueError("No repositories found in $REPO_DIR")
outputre = re.compile((r'! wall (\d+.\d+) comb \d+.\d+ user \d+.\d+ sys '
                       r'\d+.\d+ \(best of \d+\)'))

def runperfcommand(reponame, command, *args, **kwargs):
    os.environ["HGRCPATH"] = os.environ.get("ASVHGRCPATH", "")
    # for "historical portability"
    # ui.load() has been available since d83ca85
    if util.safehasattr(uimod.ui, "load"):
        ui = uimod.ui.load()
    else:
        ui = uimod.ui()
    repo = hg.repository(ui, os.path.join(reposdir, reponame))
    perfext = extensions.load(ui, 'perfext',
                              os.path.join(basedir, 'contrib', 'perf.py'))
    cmd = getattr(perfext, command)
    ui.pushbuffer()
    cmd(ui, repo, *args, **kwargs)
    output = ui.popbuffer()
    match = outputre.search(output)
    if not match:
        raise ValueError("Invalid output {0}".format(output))
    return float(match.group(1))

def perfbench(repos=reposnames, name=None, params=None):
    """decorator to declare ASV benchmark based on contrib/perf.py extension

    An ASV benchmark is a python function with the given attributes:

    __name__: should start with track_, time_ or mem_ to be collected by ASV
    params and param_name: parameter matrix to display multiple graphs on the
    same page.
    pretty_name: If defined it's displayed in web-ui instead of __name__
    (useful for revsets)
    the module name is prepended to the benchmark name and displayed as
    "category" in webui.

    Benchmarks are automatically parameterized with repositories found in the
    REPOS_DIR environment variable.

    `params` is the param matrix in the form of a list of tuple
    (param_name, [value0, value1])

    For example [(x, [a, b]), (y, [c, d])] declare benchmarks for
    (a, c), (a, d), (b, c) and (b, d).
    """
    params = list(params or [])
    params.insert(0, ("repo", repos))

    def decorator(func):
        @functools.wraps(func)
        def wrapped(repo, *args):
            def perf(command, *a, **kw):
                return runperfcommand(repo, command, *a, **kw)
            return func(perf, *args)

        wrapped.params = [p[1] for p in params]
        wrapped.param_names = [p[0] for p in params]
        wrapped.pretty_name = name
        return wrapped
    return decorator