view contrib/benchmarks/revset.py @ 47120:7109a38830c9

dirstate-tree: Fold "tracked descendants" counter update in main walk

For the purpose of implementing `has_tracked_dir` (which means "has tracked
descendants) without an expensive sub-tree traversal, we maintaing a counter
of tracked descendants on each "directory" node of the tree-shaped dirstate.

Before this changeset, mutating or inserting a node at a given path would
involve:

* Walking the tree from root through ancestors to find the node or the spot
  where to insert it
* Looking at the previous node if any to decide what counter update is needed
* Performing any node mutation
* Walking the tree *again* to update counters in ancestor nodes

When profiling `hg status` on a large repo, this second walk takes times
while loading a the dirstate from disk.

It turns out we have enough information to decide before he first tree walk
what counter update is needed. This changeset merges the two walks, gaining
~10% of the total time for `hg update` (in the same hyperfine benchmark as
the previous changeset).

---

Profiling was done by compiling with this `.cargo/config`:

    [profile.release]
    debug = true

then running with:

    py-spy record -r 500 -n -o /tmp/hg.json --format speedscope -- \
    ./hg status -R $REPO --config experimental.dirstate-tree.in-memory=1

then visualizing the recorded JSON file in https://www.speedscope.app/

Differential Revision: https://phab.mercurial-scm.org/D10554

# revset.py - asv revset benchmarks
#
# 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.

'''ASV revset benchmarks generated from contrib/base-revsets.txt

Each revset benchmark is parameterized with variants (first, last, sort, ...)
'''

from __future__ import absolute_import

import os
import string
import sys

from . import basedir, perfbench


def createrevsetbenchmark(baseset, variants=None):
    if variants is None:
        # Default variants
        variants = ["plain", "first", "last", "sort", "sort+first", "sort+last"]
    fname = "track_" + "_".join(
        "".join(
            [c if c in string.digits + string.letters else " " for c in baseset]
        ).split()
    )

    def wrap(fname, baseset):
        @perfbench(name=baseset, params=[("variant", variants)])
        def f(perf, variant):
            revset = baseset
            if variant != "plain":
                for var in variant.split("+"):
                    revset = "%s(%s)" % (var, revset)
            return perf("perfrevset", revset)

        f.__name__ = fname
        return f

    return wrap(fname, baseset)


def initializerevsetbenchmarks():
    mod = sys.modules[__name__]
    with open(os.path.join(basedir, 'contrib', 'base-revsets.txt'), 'rb') as fh:
        for line in fh:
            baseset = line.strip()
            if baseset and not baseset.startswith('#'):
                func = createrevsetbenchmark(baseset)
                setattr(mod, func.__name__, func)


initializerevsetbenchmarks()