view contrib/discovery-helper.sh @ 41881:e514799e4e07

discovery: use a lower level but faster way to retrieve parents

We already know that no revision in the undecided set are filtered, so we can
skip multiple checks and directly access lower level data.

In a private pathological case, this improves the timing from about 70 seconds
to about 50 seconds. There are other actions to be taken to improve that case,
however this gives an idea of the general overhead.

#!/bin/bash
#
# produces two repositories with different common and missing subsets
#
#   $ discovery-helper.sh REPO NBHEADS DEPT
#
# The Goal is to produce two repositories with some common part and some
# exclusive part on each side. Provide a source repository REPO, it will
# produce two repositories REPO-left and REPO-right.
#
# Each repository will be missing some revisions exclusive to NBHEADS of the
# repo topological heads. These heads and revisions exclusive to them (up to
# DEPTH depth) are stripped.
#
# The "left" repository will use the NBHEADS first heads (sorted by
# description). The "right" use the last NBHEADS one.
#
# To find out how many topological heads a repo has, use:
#
#   $ hg heads -t -T '{rev}\n' | wc -l
#
# Example:
#
#  The `pypy-2018-09-01` repository has 192 heads. To produce two repositories
#  with 92 common heads and ~50 exclusive heads on each side.
#
#    $ ./discovery-helper.sh pypy-2018-08-01 50 10

set -euo pipefail

if [ $# -lt 3 ]; then
     echo "usage: `basename $0` REPO NBHEADS DEPTH"
     exit 64
fi

repo="$1"
shift

nbheads="$1"
shift

depth="$1"
shift

leftrepo="${repo}-left"
rightrepo="${repo}-right"

left="first(sort(heads(all()), 'desc'), $nbheads)"
right="last(sort(heads(all()), 'desc'), $nbheads)"

leftsubset="ancestors($left, $depth) and only($left, heads(all() - $left))"
rightsubset="ancestors($right, $depth) and only($right, heads(all() - $right))"

echo '### building left repository:' $left-repo
echo '# cloning'
hg clone --noupdate "${repo}" "${leftrepo}"
echo '# stripping' '"'${leftsubset}'"'
hg -R "${leftrepo}" --config extensions.strip= strip --rev "$leftsubset" --no-backup

echo '### building right repository:' $right-repo
echo '# cloning'
hg clone --noupdate "${repo}" "${rightrepo}"
echo '# stripping:' '"'${rightsubset}'"'
hg -R "${rightrepo}" --config extensions.strip= strip --rev "$rightsubset" --no-backup