##// END OF EJS Templates
discovery-helper: use reflink copy if available...
discovery-helper: use reflink copy if available A reflink copy will copy the files "as usual" but keep using the same data block underneath. This is only supported by "copy on write" file system like btrfs or zfs. This will achieve similar performance that the existing hardlink clone that Mercurial performs with the same initial space saving. However, it will behave better on revlogs start being touch by strip. Instead of duplicating all data in the touched revlogs, only the block actually affected by the strip will be duplicated. This save a lot of space when building many variants of large repositories. The --reflink=always flag make sure the `cp` call fails if reflink copies are not supported. Falling back to local clone.

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discovery-helper.sh
107 lines | 2.6 KiB | application/x-sh | BashLexer
#!/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
printusage () {
echo "usage: `basename $0` REPO NBHEADS DEPTH [left|right]" >&2
}
if [ $# -lt 3 ]; then
printusage
exit 64
fi
repo="$1"
shift
nbheads="$1"
shift
depth="$1"
shift
doleft=1
doright=1
if [ $# -gt 1 ]; then
printusage
exit 64
elif [ $# -eq 1 ]; then
if [ "$1" == "left" ]; then
doleft=1
doright=0
elif [ "$1" == "right" ]; then
doleft=0
doright=1
else
printusage
exit 64
fi
fi
leftrepo="${repo}-${nbheads}h-${depth}d-left"
rightrepo="${repo}-${nbheads}h-${depth}d-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 '### creating left/right repositories with missing changesets:'
if [ $doleft -eq 1 ]; then
echo '# left revset:' '"'${leftsubset}'"'
fi
if [ $doright -eq 1 ]; then
echo '# right revset:' '"'${rightsubset}'"'
fi
buildone() {
side="$1"
dest="$2"
revset="$3"
echo "### building $side repository: $dest"
if [ -e "$dest" ]; then
echo "destination repo already exists: $dest" >&2
exit 1
fi
echo '# cloning'
if ! cp --recursive --reflink=always ${repo} ${dest}; then
hg clone --noupdate "${repo}" "${dest}"
fi
echo '# stripping' '"'${revset}'"'
hg -R "${dest}" --config extensions.strip= strip --rev "$revset" --no-backup
}
if [ $doleft -eq 1 ]; then
buildone left "$leftrepo" "$leftsubset"
fi
if [ $doright -eq 1 ]; then
buildone right "$rightrepo" "$rightsubset"
fi