hgeditor

revset: make parents() O(number of parents)

Strip executes a revset like this:

max(parents(_intlist('1234\x001235')) - _intlist('1234\x001235'))

Previously the parents() revset would do 'subset & parents' which iterates over
each item in the subset and checks if it's in parents.  subset is usually the
entire repo (a spanset) so this takes a while.

Reversing the parameters to be 'parents & subset' means the operation becomes
O(number of parents) instead of O(size of repo). It also means the result gets
evaluated immediately (since parents isn't a lazy set), but I think this is a
win in most scenarios.

This shaves 0.3 seconds off strip (amend/histedit/rebase/etc) for large repositories.

revset #0: parents(20000)
0) obsolete feature not enabled but 54243 markers found!
! wall 0.006256 comb 0.010000 user 0.010000 sys 0.000000 (best of 289)
1) obsolete feature not enabled but 54243 markers found!
! wall 0.000391 comb 0.000000 user 0.000000 sys 0.000000 (best of 4323)

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

# 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 $?