contrib/relnotes

stream-clone: disable gc for the initial section for the v3 format

The number of small container created turn Python in a gc-frenzy that seriously
impact performance.

This significantly boost performance. The following number comes from a large
private repository using perf::stream-locked-section:

base-line:   35.04 seconds
prev-change: 24.51 seconds (-30%)
prev-change: 20.88 seconds (-40%)
this-change: 14.22 seconds (-60% from baseline; -31% from prev)

#!/usr/bin/env python3
"""Generate release notes from our commit log.

This uses the relnotes extension directives when they're available,
and falls back to our old pre-relnotes logic that used to live in the
release-tools repo.
"""
import argparse
import re
import subprocess

rules = {
    # keep
    r"\(issue": 100,
    r"\(BC\)": 100,
    r"\(API\)": 100,
    r"\(SEC\)": 100,
    # core commands, bump up
    r"(commit|files|log|pull|push|patch|status|tag|summary)(|s|es):": 20,
    r"(annotate|alias|branch|bookmark|clone|graft|import|verify).*:": 20,
    # extensions, bump up
    r"(mq|shelve|rebase):": 20,
    # newsy
    r": deprecate": 20,
    r": new.*(extension|flag|module)": 10,
    r"( ability|command|feature|option|support)": 10,
    # experimental
    r"hg-experimental": 20,
    r"(from|graduate).*experimental": 15,
    r"(hide|mark).*experimental": -10,
    # bug-like?
    r"(fix|don't break|improve)": 7,
    r"(not|n't|avoid|fix|prevent).*crash": 10,
    r"vulnerab": 10,
    # boring stuff, bump down
    r"^contrib": -5,
    r"debug": -5,
    r"help": -5,
    r"minor": -5,
    r"(doc|metavar|bundle2|obsolete|obsmarker|rpm|setup|debug\S+:)": -15,
    r"(check-code|check-commit|check-config|import-checker)": -20,
    r"(flake8|lintian|pyflakes|pylint)": -20,
    # cleanups and refactoring
    r"(clean ?up|white ?space|spelling|quoting)": -20,
    r"(flatten|dedent|indent|nesting|unnest)": -20,
    r"(typo|hint|note|comment|TODO|FIXME)": -20,
    r"(style:|convention|one-?liner)": -20,
    r"(argument|absolute_import|attribute|assignment|mutable)": -15,
    r"(scope|True|False)": -10,
    r"(unused|useless|unnecessar|superfluous|duplicate|deprecated)": -10,
    r"(redundant|pointless|confusing|uninitialized|meaningless|dead)": -10,
    r": (drop|remove|delete|rip out)": -10,
    r": (inherit|rename|simplify|naming|inline)": -10,
    r"(correct doc|docstring|document .* method)": -20,
    r"(abstract|factor|extract|prepare|split|replace| import)": -20,
    r": add.*(function|method|implementation|example)": -10,
    r": (move|extract) .* (to|into|from|out of)": -20,
    r": implement ": -5,
    r": use .* implementation": -20,
    r": use .* instead of": -20,
    # code
    r"_": -10,
    r"__": -5,
    r"\(\)": -5,
    r"\S\S\S+\.\S\S\S\S+": -5,
    # dumb keywords
    r"\S+/\S+:": -10,
    r"\S+\.\S+:": -10,
    # python compatibility
    r"[Pp]y(|thon) ?[23]": -20,
    r"pycompat": -20,
    r"(coerce|convert|encode) .*to (byte|sys|)(s|str|string)": -20,
    # tests
    r"^test(|s|ing|runner|-\S+):": -20,
    r"^(f|hghave|run-tests):": -20,
    r"add.* tests?": -20,
    r"(buildbot|fuzz|mock|ratchet)": -10,
    # drop
    r"^i18n-": -50,
    r"^i18n:.*(hint|comment)": -50,
    r"perf:": -50,
    r"Added.*for changeset": -50,
    r"^_": -50,
}

cutoff = 10
commits = []

groupings = [
    (r"util|parsers|repo|ctx|context|revlog|filelog|alias|cmdutil", "core"),
    (r"revset|template|ui|dirstate|hook|i18n|transaction|wire|vfs", "core"),
    (r"dispatch|exchange|localrepo|streamclone|color|pager", "core"),
    (r"hgweb|paper|coal|gitweb|monoblue|spartan", "hgweb"),
    (r"pull|push|revert|resolve|annotate|bookmark|branch|clone", "commands"),
    (r"commands|commit|config|files|graft|import|log|merge|patch", "commands"),
    (r"phases|status|summary|amend|tag|help|verify", "commands"),
    (r"rebase|mq|convert|eol|histedit|largefiles", "extensions"),
    (r"shelve|unshelve", "extensions"),
]


def wikify(desc):
    desc = desc.replace("(issue", "(Bts:issue")
    desc = re.sub(r"\b([0-9a-f]{12})\b", r"Cset:\1", desc)
    # stop ParseError from being recognized as a (nonexistent) wiki page
    desc = re.sub(r" ([A-Z][a-z]+[A-Z][a-z]+)\b", r" !\1", desc)
    # prevent wiki markup of magic methods
    desc = re.sub(r"\b(\S*__\S*)\b", r"`\1`", desc)
    return desc


def main():
    desc = "example: %(prog)s 4.7.2 --stoprev 4.8rc0"
    ap = argparse.ArgumentParser(description=desc)
    ap.add_argument(
        "startrev",
        metavar="REV",
        type=str,
        help=(
            "Starting revision for the release notes. This revision "
            "won't be included, but later revisions will."
        ),
    )
    ap.add_argument(
        "--stoprev",
        metavar="REV",
        type=str,
        default="@",
        help=(
            "Stop revision for release notes. This revision will be included,"
            " but no later revisions will. This revision needs to be "
            "a descendant of startrev."
        ),
    )
    args = ap.parse_args()
    fromext = subprocess.check_output(
        [
            "hg",
            "--config",
            "extensions.releasenotes=",
            "releasenotes",
            "-r",
            "only(%s, %s)" % (args.stoprev, args.startrev),
        ]
    ).decode("utf-8")
    # Find all release notes from un-relnotes-flagged commits.
    for entry in sorted(
        subprocess.check_output(
            [
                "hg",
                "log",
                "-r",
                "only(%s, %s) - merge()" % (args.stoprev, args.startrev),
                "-T",
                r"{desc|firstline}\n",
            ]
        )
        .decode("utf-8")
        .splitlines()
    ):
        desc = entry.replace("`", "'")

        score = 0
        for rule, val in rules.items():
            if re.search(rule, desc):
                score += val

        if score >= cutoff:
            commits.append(wikify(desc))
    # Group unflagged notes.
    groups = {}
    bcs = []
    apis = []

    for d in commits:
        if "(BC)" in d:
            bcs.append(d)
        if "(API)" in d:
            apis.append(d)
        for rule, g in groupings:
            if re.match(rule, d):
                groups.setdefault(g, []).append(d)
                break
        else:
            groups.setdefault("unsorted", []).append(d)
    print(fromext)
    # print legacy release notes sections
    for g in sorted(groups):
        print("\n=== %s ===" % g)
        for d in sorted(groups[g]):
            print(" * %s" % d)

    if bcs:
        print("\n=== Behavior Changes ===\n")

    for d in sorted(bcs):
        print(" * %s" % d)

    if apis:
        print("\n=== Internal API Changes ===\n")

    for d in sorted(apis):
        print(" * %s" % d)


if __name__ == "__main__":
    main()