view hgeditor @ 18063:34a1a639d835

revset.children: ignore rev numbers that are too low

This replaces unnecessary parentrevs() calls with calculating min(parentset).
Even though the min operation is O(size of parentset), since parentrevs is
relatively expensive, this tradeoff almost always works in our favour. In a
repository with over 400,000 changesets, hg perfrevset "children(X)" takes:

       Set X       Before    After
       -1           0.51s    0.06s
    -1000:          0.55s    0.08s
   -10000:          0.56s    0.10s
  -100000:          0.60s    0.25s
  -100000:-99000    0.55s    0.19s
        0:100000    0.60s    0.61s
      all()         0.72s    0.74s

The relative performance is similar for Mercurial's own repository -- several
times faster in most cases, slightly slower for revisions close to 0 and
all().

#!/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 $?