view hgeditor @ 27633:37d7cf569cf3

wireproto: support disabling bundle1 only if repo is generaldelta

I recently implemented the server.bundle1* options to control whether
bundle1 exchange is allowed.

After thinking about Mozilla's strategy for handling generaldelta
rollout a bit more, I think server operators need an additional
lever: disable bundle1 if and only if the repo is generaldelta.

bundle1 exchange for non-generaldelta repos will not have the potential
for CPU explosion that generaldelta repos do. Therefore, it makes sense
for server operators to continue to allow bundle1 exchange for
non-generaldelta repos without having to set a per-repo hgrc option
to change the policy depending on whether the repo is generaldelta.

This patch introduces a new set of options to control bundle1 behavior
for generaldelta repos. These options enable server operators to limit
bundle1 restrictions to the class of repos that can be performance
issues. It also allows server operators to tie bundle1 access to store
format. In many server environments (including Mozilla's), legacy repos
will not be generaldelta and new repos will or might be. New repos often
aren't bound by legacy access requirements, so setting a global policy
that disallows access to new/generaldelta repos via bundle1 could be a
reasonable policy in many server environments. This patch makes this
policy very easy to implement (modify global hgrc, add options to
existing generaldelta repos to grandfather them in).

#!/bin/sh
#
# This is an example of using HGEDITOR to create of diff to review the
# changes while committing.

# If you want to pass your favourite editor some other parameters
# only for Mercurial, modify this:
case "${EDITOR}" in
    "")
        EDITOR="vi"
        ;;
    emacs)
        EDITOR="$EDITOR -nw"
        ;;
    gvim|vim)
        EDITOR="$EDITOR -f -o"
        ;;
esac


HGTMP=""
cleanup_exit() {
    rm -rf "$HGTMP"
}

# Remove temporary files even if we get interrupted
trap "cleanup_exit" 0 # normal exit
trap "exit 255" HUP INT QUIT ABRT TERM

HGTMP=$(mktemp -d ${TMPDIR-/tmp}/hgeditor.XXXXXX)
[ x$HGTMP != x -a -d $HGTMP ] || {
  echo "Could not create temporary directory! Exiting." 1>&2
  exit 1
}

(
    grep '^HG: changed' "$1" | cut -b 13- | while read changed; do
        "$HG" diff "$changed" >> "$HGTMP/diff"
    done
)

cat "$1" > "$HGTMP/msg"

MD5=$(which md5sum 2>/dev/null) || \
    MD5=$(which md5 2>/dev/null)
[ -x "${MD5}" ] && CHECKSUM=`${MD5} "$HGTMP/msg"`
if [ -s "$HGTMP/diff" ]; then
    $EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $?
else
    $EDITOR "$HGTMP/msg" || exit $?
fi
[ -x "${MD5}" ] && (echo "$CHECKSUM" | ${MD5} -c >/dev/null 2>&1 && exit 13)

mv "$HGTMP/msg" "$1"

exit $?