[arch-projects] [mkinitcpio][PATCH 18/19] lsinitcpio: extract the image to a tempdir

[Dan McGee]

On Sun, May 13, 2012 at 12:57 PM, Dave Reisner <dreisner at archlinux.org> wrote:
> We read the image a number of times. Extract the image to a temp
> directory so we can just extract it once and use the filesystem to our
> advantage. This requires a temp dir which we can nuke on an EXIT trap,
> but the whole operation is sped is a bit, especially for larger images.
>
> The real goal of this is to make examination of the hooks easier. Since
> we now have multiple hook sets to contend with, dynamically tally up the
> available functions in the hook files so we can iterate over specific
> functions of interest in the output.
>
> Signed-off-by: Dave Reisner <dreisner at archlinux.org>
> ---

You missed one:
        TIMEFORMAT=%R decomptime=$({ time decomp "$image" >/dev/null; } 2>&1 )

This is guarded by a 'if compressed' block now, but it is probably
useful even if you are using an uncompressed tar image- there is still
work being done in reading and breaking the individual files out of
the tarfile.


>  lsinitcpio |   59 +++++++++++++++++++++++++++++++++++++++++------------------
>  1 file changed, 41 insertions(+), 18 deletions(-)
>
> diff --git a/lsinitcpio b/lsinitcpio
> index 5abe37f..f33d9d3 100755
> --- a/lsinitcpio
> +++ b/lsinitcpio
> @@ -59,7 +59,6 @@ size_to_human() {
>     }'
>  }
>
> -
>  OPT_SHORT='ahnvx'
>  OPT_LONG=('analyze' 'help' 'nocolor' 'verbose' 'extract')
>
> @@ -127,6 +126,9 @@ if (( analyze )); then
>     declare -a binaries explicitmod modules foundhooks hooks
>     declare kernver ratio columns=$(tput cols)
>
> +    workdir=$(mktemp -d --tmpdir="$TMPDIR" lsinitcpio.XXXXXX)
> +    trap 'rm -rf "$workdir"' EXIT
> +
>     # fallback in case tput failed us
>     columns=${columns:-80}
>
> @@ -139,27 +141,48 @@ if (( analyze )); then
>         ratio=.$(( zsize * 1000 / fullsize % 1000 ))
>     fi
>
> -    # read contents of image
> -    while read -r line; do
> -        if [[ $line = *.ko?(.?z) ]]; then
> -            line=${line##*/}
> -            modules+=("${line%.ko?(.?z)}")
> -        elif [[ -z $kernver && $line =~ /lib/modules/([^/]+)/ ]]; then
> -            kernver=${BASH_REMATCH[1]}
> -        elif [[ $line = ./hooks/* ]]; then
> -            foundhooks+=("${line##*/}")
> -        elif [[ $line = *@(/?(s)bin/)* ]]; then
> -            binaries+=("${line##*/}")
> -        fi
> -    done < <(decomp "$image" | bsdtar tf -)
> -
> -    read -r version < <(decomp "$image" | bsdtar xOf - VERSION 2>/dev/null)
> +    # decompress the image since we need to read from it multiple times
> +    decomp "$image" | bsdtar -C "$workdir" -xf -
> +
> +    # collect stats
> +    kernver=("$workdir"/usr/lib/modules/*/)
> +    kernver=${kernver%/}
> +    kernver=${kernver##*/}
> +
> +    modules=("$workdir/usr/lib/modules/$kernver"/kernel/*.ko*)
> +    modules=("${modules[@]##*/}")
> +    modules=("${modules[@]%.ko*}")
> +
> +    foundhooks=("$workdir"/hooks/*)
> +    foundhooks=("${foundhooks[@]##*/}")
> +
> +    binaries=("$workdir"/usr/bin/*)
> +    binaries=("${binaries[@]##*/}")
> +
> +    read -r version < "$workdir/VERSION"
>
>     # source and read config
> -    . <(decomp "$image" | bsdtar xOf - config)
> +    . "$workdir/config"
> +
>     explicitmod=($MODULES)
> +
>     for hook in $HOOKS; do
> -        in_array "$hook" "${foundhooks[@]}" && hooks+=("$hook")
> +        [[ -e $workdir/hooks/$hook ]] || continue
> +
> +        mapfile -t funcs < \
> +            <(awk '
> +                /^[[:space:]]*[[:alnum:]_]+/ && /\([[:space:]]*\)/ {
> +                    match($1, /[[:alnum:]_]+/)
> +                    print substr($1, RSTART, RLENGTH)
> +                }' "$workdir/hooks/$hook")
> +
> +        for fn in "${funcs[@]}"; do
> +            case $fn in
> +                run_hook)
> +                    hooks+=("$hook")
> +                    ;;
> +            esac
> +        done
>     done
>
>     # print results
> --
> 1.7.10.2
>