#!/bin/sh
set -e

if [ "$1" = prereqs ]; then
  exit 0
fi

. /usr/share/initramfs-tools/hook-functions

number=
suffix=
eval $(printf "%s" "$COMPCACHE_SIZE" | \
       sed -nre 's/^ *([1-9][0-9]*) *([%KMGT]) *$/number="\1"; suffix="\2";/p')

if [ -z "$number" ] || [ -z "$suffix" ]; then
  exit 0
fi

if have_module zram; then
  name=zram
  manual_add_modules zram
elif have_module ramzswap; then
  name=ramzswap
  manual_add_modules ramzswap
elif have_module compcache; then
  name=compcache
  manual_add_modules compcache
else
  exit 0
fi

copy_exec /sbin/swapon
copy_exec /sbin/mkswap
copy_exec /usr/lib/initramfs-tools/bin/rzscontrol /sbin

mem_total="\$(sed -nre 's/^MemTotal:\\s*([0-9]+) kB\$/\\1/p' /proc/meminfo)"

case "$suffix" in
%) kbytes="\$(($mem_total * $number / 100))" ;;
K) kbytes=$(($number))                       ;;
M) kbytes=$(($number * 1024))                ;;
G) kbytes=$(($number * 1024 * 1024))         ;;
T) kbytes=$(($number * 1024 * 1024 * 1024))  ;;
esac

cat >"$DESTDIR"/sbin/compcache-enable <<'EOF'
#!/bin/sh
if [ "$#" != 3 ]; then
	echo "Usage: $0 <type> <size> <device>" 1>&2
	exit 1
fi
type="$1"
size="$2"
device="$3"

number=
suffix=
eval $(printf "%s" "$size" | \
       sed -nre 's/^ *([1-9][0-9]*) *([%KMGT]) *$/number="\1"; suffix="\2";/p')

mem_total="$(sed -nre 's/^MemTotal:\s*([0-9]+) kB$/\1/p' /proc/meminfo)"

case "$suffix" in
%) kbytes="$(($mem_total * $number / 100))" ;;
K) kbytes=$(($number))                       ;;
M) kbytes=$(($number * 1024))                ;;
G) kbytes=$(($number * 1024 * 1024))         ;;
T) kbytes=$(($number * 1024 * 1024 * 1024))  ;;
esac
bytes="$(($kbytes * 1024))"

if [ "$type" = zram ]; then
	echo "$bytes" >/sys/block/$device/disksize && \
	/sbin/mkswap "/dev/$device" >/dev/null

elif [ "$type" = ramzswap ]; then
	/sbin/rzscontrol "/dev/$device" --disksize_kb="$kbytes" --init
fi
/sbin/swapon -p 100 "/dev/$device" 2>/dev/null

exit 0
EOF
chmod 0755 "$DESTDIR"/sbin/compcache-enable

mkdir -p "$DESTDIR"/etc/udev/rules.d
if [ "$name" = zram ]; then
  cat >"$DESTDIR"/etc/udev/rules.d/80-compcache.rules <<EOF
KERNEL=="zram0", ACTION=="add", \\
  RUN+="/sbin/compcache-enable zram $COMPCACHE_SIZE zram0"
EOF
elif [ "$name" = ramzswap ]; then
  cat >"$DESTDIR"/etc/udev/rules.d/80-compcache.rules <<EOF
KERNEL=="ramzswap0", ACTION=="add", \\
  RUN+="/sbin/compcache-enable ramzswap $COMPCACHE_SIZE ramzswap0"
EOF
else
  cat >"$DESTDIR"/etc/udev/rules.d/80-compcache.rules <<EOF
KERNEL=="ramzswap0", ACTION=="add", \\
  RUN+="/sbin/compcache-enable compcache $COMPCACHE_SIZE ramzswap0"
EOF
fi

cat >"$DESTDIR"/scripts/init-top/compcache <<EOF
#!/bin/sh

PREREQ=""
prereqs()
{
     echo "\$PREREQ"
}

case \$1 in
prereqs)
     prereqs
     exit 0
     ;;
esac

# find total amount of available ram
TOTAL_RAM=\$( grep MemTotal /proc/meminfo |tr -d ': [A-Z][a-z]')

# Do not use compcache on the liveCD if we have more than 512M
if [ "\${BOOT}" = "casper" ]; then
    if [ "\${TOTAL_RAM}" -gt 524288 ]; then
        exit 0
    fi
fi

for x in \$(cat /proc/cmdline); do
        case \${x} in
        nocompcache)
                exit 0
        ;;
        esac
done

EOF

if [ "$name" = zram ]; then
  cat >>"$DESTDIR"/scripts/init-top/compcache <<EOF
modprobe -q --ignore-install zram
EOF
elif [ "$name" = ramzswap ]; then
  cat >>"$DESTDIR"/scripts/init-top/compcache <<EOF
modprobe -q --ignore-install ramzswap
EOF
else
  cat >>"$DESTDIR"/scripts/init-top/compcache <<EOF
modprobe -q --ignore-install compcache compcache_size_kbytes="$kbytes"
EOF
fi

chmod 0755 "$DESTDIR"/scripts/init-top/compcache

# vim:set et sw=2 sts=2: