squash-bench.sh

#!/bin/sh

set -e

free_caches() {
  sudo sync
  printf "Freeing caches: "
  for i in 1 2 3; do 
      sudo sysctl -q vm.drop_caches="$i"
  done
  echo "done."
}

benchmark_walk() {
    SNAP="$1"
    free_caches >&2

    start=$(date +%s%N)
    find "/snap/$SNAP/current/" -type f -print0 | xargs -0 md5sum >/dev/null
    end=$(date +%s%N)

    echo $(( (end - start)/1000000 ))
}

benchmark_startup() {
    SNAP="$1"
    APP="/snap/bin/$SNAP"
    case "$SNAP" in
        supertuxkart)
            NEEDLE="SuperTuxKart"
            ;;
        chromium)
            NEEDLE="New Tab - Chromium"
            ;;
        mari0)
            NEEDLE="Mari0"
            ;;
        gnome-calculator)
            NEEDLE="Calculator"
            ;;
        test-snapd-glxgears)
            NEEDLE="glxgears"
            ;;
        *)
            echo "EEE  No window name known for $SNAP; bailing out" >&2
            return 1
            ;;
    esac
    free_caches >&2

    start=$(date +%s%N)
    "$APP" >/dev/null 2>&1 &
    while ! wmctrl -l | grep -q "$NEEDLE"; do
        true
    done
    end=$(date +%s%N)
    TIME=$(( (end - start)/1000000 ))
    # close window
    wmctrl -c "$NEEDLE"
    # wait for window to disappear
    while wmctrl -l | grep -q "$NEEDLE"; do
        true
    done
    echo "$TIME"
}

recompress() {
    snap="$1"
    comp="$2"
    if [ "$comp" = "none" ]; then
        set -- -noI -noD -noF
    else
        set -- -comp "$comp"
    fi

    mksquashfs "$snap-root" "$snap-$comp.snap" -noappend -no-fragments -all-root -no-xattrs "$@"
}

bench() {
    SNAP="$1"
    MODE="$2"
    ITER="$3"
    if [ "$MODE" != "try" ]; then
        if [ "$MODE" != "xz" ]; then
            if [ ! -e "$SNAP-$MODE.snap" ]; then
                recompress "$SNAP" "$MODE" >&2
            fi
        fi
        sudo snap install --dangerous "$SNAP-$MODE.snap" >&2
        SIZE=$( stat -Lc%s "$SNAP-${MODE}.snap" )
    else
        sudo snap try "$SNAP-root" >&2
        SIZE=$( du -bs "$SNAP-root" | cut -f1 )
    fi

    # connect every interface declared
    for iface in $(snap interfaces "$SNAP" 2>/dev/null | grep -P "^-" | awk '{print $2}'); 
        do snap connect "$iface" >&2
    done

    START=$( benchmark_startup "$SNAP" )
    echo "$SNAP ($MODE): starting took ${START}ms" >&2

    START2=$( benchmark_startup "$SNAP" )
    echo "$SNAP ($MODE): 2nd start took ${START2}ms" >&2

    START3=$( benchmark_startup "$SNAP" )
    echo "$SNAP ($MODE): 3rd start took ${START3}ms" >&2

    START4=$( benchmark_startup "$SNAP" )
    echo "$SNAP ($MODE): 4th start took ${START4}ms" >&2

    WALK=$( benchmark_walk "$SNAP" )
    echo "$SNAP ($MODE): walk took ${WALK}ms" >&2
    
    sudo snap remove "$SNAP" >&2

    echo "$ITER:$SNAP:$MODE:$SIZE:$START:$START2:$START3:$START4:$WALK"
}

prepare() {
    SNAP="$1"
    if [ ! -d "$SNAP-root" ]; then
        snap download "$SNAP"
        sudo unsquashfs -d "$SNAP-root" "$SNAP"_*.snap
        ln -sfv "$SNAP"_*.snap "$SNAP-xz.snap"
    fi
    if snap list "$SNAP" >/dev/null 2>&1; then
        sudo snap remove "$SNAP"
    fi
}

if [ "$(id -u)" -eq 0 ]; then
    echo "ERROR! Must be a regular user."
    exit 1
fi

# Init
# snap version > log.txt
# echo "SNAP:MODE:SIZE:START:START2:WALK" >> log.txt
sudo true
if ! command -v wmctrl >/dev/null; then
    sudo apt install wmctrl
fi

for ITER in $(seq 1 10); do
    for SNAP in supertuxkart chromium mari0 gnome-calculator test-snapd-glxgears; do
        echo "#### $SNAP"
        prepare "$SNAP"

        for MODE in try xz none gzip lzo zstd; do
            echo "  ## $MODE"
            bench "$SNAP" "$MODE" "$ITER" | tee -a log.txt
        done
    done
done

echo Finished
cat log.txt