A script to calculate a push strategy for a ref, given a pack size limit.

packsize.sh

#!/bin/bash
LIMIT=$1
TIP=$2

BS=$(( 64 * 1024 ))
COUNT=$(( ( $LIMIT ) / $BS ))

packsize() {
	COMMITS=$1
	ENDPOINT=$TOP
	STARTPOINT=`git rev-parse $ENDPOINT~$COMMITS 2>/dev/null` || return 1
	echo $STARTPOINT..$ENDPOINT |
	git pack-objects -q --stdout --revs | 
	dd bs=$BS skip=$COUNT count=0 2>/dev/null &&
	return 1 || return 0
}

parents=`git rev-list $TIP --first-parent --count` || exit 128
acc=0
TOP=$TIP
i=1
while [ $(( $acc )) -lt $parents ]
do
	n=0
	while packsize $i
	do
		printf .
		n=$i
		NEWTOP=$STARTPOINT
		let i=i*2
	done
	[ $n -eq 0 ] &&
	while [ $i -gt 1 ]
	do
		printf ,
		let i=i/2
		packsize $i &&
		{
			n=$i
			NEWTOP=$STARTPOINT
			break
		}
	done
	[ $n -eq 0 ] && break
	acc=$acc+$n
	TOP=$NEWTOP
	i=$n
	printf $n
done
echo
[ $(( $acc )) -lt $parents ] && acc=$acc+$(( $parents - ( $acc ) ))
echo $TIP'~$(('$acc'))'