Re: [pacman-dev] [PATCH] Add a timestamp file into repo tarballs

[Morten Linderud]

On Tue, Nov 05, 2019 at 11:54:34PM +1000, Allan McRae wrote:
> When creating or modifying repo tarballs, place a .TIMESTAMP file with
> seconds since epoch in it.  This will be used in the future to enable
> rejecting databases older that a given threshold.
> 
> Also skip reading the .TIMESTAMP file in sync_db_populate().
> 
> Signed-off-by: Allan McRae <al...@archlinux.org>
> ---
> 
> Anyone want to check my logic in the sync_db_populate() populate change?
> Repo-add puts the .TIMESTAMP file first when calling bsdtar, so if present
> it will be first in the repo db file.  Otherwise the first item read from
> the tarball will be a directory, which we skip reading anyway.  So I just
> read the header for the first item and discard it.
> 
>  lib/libalpm/be_sync.c  | 9 +++++++++
>  scripts/repo-add.sh.in | 8 +++++---
>  2 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
> index 2c76fe83..041b2266 100644
> --- a/lib/libalpm/be_sync.c
> +++ b/lib/libalpm/be_sync.c
> @@ -506,6 +506,13 @@ static int sync_db_populate(alpm_db_t *db)
>               goto cleanup;
>       }
>  
> +     /* the .TIMESTAMP file will be first entry in the repo archive if 
> present.
> +      * If not, the first entry will be a directory and can be skipped too */
> +     if((archive_ret = archive_read_next_header(archive, &entry)) != 
> ARCHIVE_OK) {
> +             ret = -1;
> +             goto readfail;
> +     }
> +
>       while((archive_ret = archive_read_next_header(archive, &entry)) == 
> ARCHIVE_OK) {
>               mode_t mode = archive_entry_mode(entry);
>               if(!S_ISDIR(mode)) {
> @@ -518,6 +525,8 @@ static int sync_db_populate(alpm_db_t *db)
>                       }
>               }
>       }
> +
> +readfail:
>       if(archive_ret != ARCHIVE_EOF) {
>               _alpm_log(db->handle, ALPM_LOG_ERROR, _("could not read db '%s' 
> (%s)\n"),
>                               db->treename, archive_error_string(archive));
> diff --git a/scripts/repo-add.sh.in b/scripts/repo-add.sh.in
> index caf1232d..c87409f1 100644
> --- a/scripts/repo-add.sh.in
> +++ b/scripts/repo-add.sh.in
> @@ -526,6 +526,7 @@ create_db() {
>       TAR_OPT=$(verify_repo_extension "$REPO_DB_FILE")
>       # $LOCKFILE is already guaranteed to be absolute so this is safe
>       dirname=${LOCKFILE%/*}
> +     timestamp=$(date +%s)

This should probably utilize SOURCE_DATE_EPOCH or something equivalent?

timestamp=$(date --date="@${SOURCE_DATE_EPOCH:-$(date +%s)}" +%s))

>       for repo in "db" "files"; do
>               filename=${REPO_DB_PREFIX}.${repo}.${REPO_DB_SUFFIX}
> @@ -533,12 +534,13 @@ create_db() {
>               tempname=$dirname/.tmp.$filename
>  
>               pushd "$tmpdir/$repo" >/dev/null
> +             echo $timestamp > .TIMESTAMP
>               if ( shopt -s nullglob; files=(*); (( ${#files[*]} )) ); then
> -                     bsdtar -c ${TAR_OPT} -f "$tempname" *
> +                     bsdtar -c ${TAR_OPT} -f "$tempname" .TIMESTAMP *
>               else
> -                     # we have no packages remaining? zip up some emptyness
> +                     # we have no packages remaining
>                       warning "$(gettext "No packages remain, creating empty 
> database.")"
> -                     bsdtar -c ${TAR_OPT} -f "$tempname" -T /dev/null
> +                     bsdtar -c ${TAR_OPT} -f "$tempname" .TIMESTAMP
>               fi
>               popd >/dev/null
>  
> -- 
> 2.23.0

-- 
Morten Linderud
PGP: 9C02FF419FECBE16

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