#!/bin/sh -e
# tally up sizes of chroot's ELF binaries for squashfs tuning

# NB: it's unclear so far whether mksquashfs -sort is beneficial
if [ -z "$GLOBAL_SQUASHFS_SORT" -o "$GLOBAL_SQUASHFS" != "tight" ]; then
	echo "SKIP elf-stats: looks like it's not needed" >&2
	exit 0
fi

exit_handler()
{
	local rc=$1
	rm -f -- "$TMPFILE"
	exit $rc
}

# it's controlled environment
TMPFILE="$(mktemp)"

trap 'exit_handler $?' EXIT HUP PIPE INT QUIT TERM

# a list of ELF binaries (both executables and shared libraries)
ELFLIST=/.our/elf.lst

cd "$WORKDIR"

# let's parallelize a bit, chroot should be on tmpfs or just-cached
du -bsx | cut -f1 > "$TMPFILE" &

elf="$(find {,usr/}{lib*,{,s}bin} \
		-path lib/modules -prune -o \
		-path usr/lib/locale -prune -o \
		-type f \
	| file -nN -e ascii -e compress -e tar -e elf -f - \
	| sed -n "/: ELF /s/: .*$//p" \
	| tee "$ELFLIST.in" \
	| tr '\n' '\0' \
	| du -cb --files0-from=- \
	| tail -1 \
	| cut -f1)"

wait
read root < "$TMPFILE"

echo "** live chroot ELF ratio: $((100*$elf/$root))% ($elf/$root)" >&2

# add priorities
sed 's,^.*$,& 1,' < "$ELFLIST.in" > "$ELFLIST"