view contrib/fuzz/dirs_corpus.py @ 46775:c94fa884240b

rust: Preallocate the returned `Vec` in `utils::files::relativize_path`

Profiling `rhg files > /dev/null` on an old snapshot of mozilla-central
(with `perf` and the Firefox Profiler:
https://github.com/firefox-devtools/profiler/blob/main/docs-user/guide-perf-profiling.md)
showed non-trivial time spend in this function and in `realloc`.

This change makes the wall-clock time for that process on my machine
go from ~190 ms to ~150 ms.

Differential Revision: https://phab.mercurial-scm.org/D10199

from __future__ import absolute_import, print_function

import argparse
import zipfile

ap = argparse.ArgumentParser()
ap.add_argument("out", metavar="some.zip", type=str, nargs=1)
args = ap.parse_args()

with zipfile.ZipFile(args.out[0], "w", zipfile.ZIP_STORED) as zf:
    zf.writestr(
        "greek-tree",
        "\n".join(
            [
                "iota",
                "A/mu",
                "A/B/lambda",
                "A/B/E/alpha",
                "A/B/E/beta",
                "A/D/gamma",
                "A/D/G/pi",
                "A/D/G/rho",
                "A/D/G/tau",
                "A/D/H/chi",
                "A/D/H/omega",
                "A/D/H/psi",
            ]
        ),
    )