On Thu, Sep 07, 2023 at 05:52:04PM -0400, Taylor Blau wrote:
[snip]
> @@ -125,17 +133,39 @@ static void mark_packs_for_deletion_1(struct string_list *names,
> if (len < hexsz)
> continue;
> sha1 = item->string + len - hexsz;
> - /*
> - * Mark this pack for deletion, which ensures that this
> - * pack won't be included in a MIDX (if `--write-midx`
> - * was given) and that we will actually delete this pack
> - * (if `-d` was given).
> - */
> - if (!string_list_has_string(names, sha1))
> - item->util = (void*)1;
> +
> + if (pack_is_retained(item)) {
> + item->util = NULL;
> + } else if (!string_list_has_string(names, sha1)) {
> + /*
> + * Mark this pack for deletion, which ensures
> + * that this pack won't be included in a MIDX
> + * (if `--write-midx` was given) and that we
> + * will actually delete this pack (if `-d` was
> + * given).
> + */
> + item->util = DELETE_PACK;
> + }
I find the behaviour of this function a tad surprising as it doesn't
only mark a pack for deletion, but it also marks a pack as not being
retained anymore. Shouldn't we rather:
if (pack_is_retained(item)) {
// Theoretically speaking we shouldn't even do this bit here as
// we _un_mark the pack for deletion. But at least we shouldn't
// be removing the `RETAIN_PACK` bit, I'd think.
item->util &= ~DELETE_PACK;
} else if (!string_list_has_string(names, sha1)) {
// And here we shouldn't discard the `RETAIN_PACK` bit either.
item->util |= DELETE_PACK;
}
> }
> }
>
> +static void retain_cruft_pack(struct existing_packs *existing,
> + struct packed_git *cruft)
> +{
> + struct strbuf buf = STRBUF_INIT;
> + struct string_list_item *item;
> +
> + strbuf_addstr(&buf, pack_basename(cruft));
> + strbuf_strip_suffix(&buf, ".pack");
> +
> + item = string_list_lookup(&existing->cruft_packs, buf.buf);
> + if (!item)
> + BUG("could not find cruft pack '%s'", pack_basename(cruft));
> +
> + item->util = (void*)RETAIN_PACK;
> + strbuf_release(&buf);
> +}
> +
Similarly, should we handle potentially pre-existing bits gracefully and
`item->util |= RETAIN_PACK`?
> static void mark_packs_for_deletion(struct existing_packs *existing,
> struct string_list *names)
>
> @@ -217,6 +247,8 @@ static void collect_pack_filenames(struct existing_packs *existing,
> }
>
> string_list_sort(&existing->kept_packs);
> + string_list_sort(&existing->non_kept_packs);
> + string_list_sort(&existing->cruft_packs);
> strbuf_release(&buf);
> }
>
> @@ -799,6 +831,72 @@ static void remove_redundant_bitmaps(struct string_list *include,
> strbuf_release(&path);
> }
>
> +static int existing_cruft_pack_cmp(const void *va, const void *vb)
> +{
> + struct packed_git *a = *(struct packed_git **)va;
> + struct packed_git *b = *(struct packed_git **)vb;
> +
> + if (a->pack_size < b->pack_size)
> + return -1;
> + if (a->pack_size > b->pack_size)
> + return 1;
> + return 0;
> +}
> +
> +static void collapse_small_cruft_packs(FILE *in, unsigned long max_size,
We might want to use `size_t` to denote file sizes instead of `unsigned
long`.
> + struct existing_packs *existing)
> +{
> + struct packed_git **existing_cruft, *p;
> + struct strbuf buf = STRBUF_INIT;
> + unsigned long total_size = 0;
Here, as well.
> + size_t existing_cruft_nr = 0;
> + size_t i;
> +
> + ALLOC_ARRAY(existing_cruft, existing->cruft_packs.nr);
> +
> + for (p = get_all_packs(the_repository); p; p = p->next) {
> + if (!(p->is_cruft && p->pack_local))
> + continue;
> +
> + strbuf_reset(&buf);
> + strbuf_addstr(&buf, pack_basename(p));
> + strbuf_strip_suffix(&buf, ".pack");
> +
> + if (!string_list_has_string(&existing->cruft_packs, buf.buf))
> + continue;
> +
> + if (existing_cruft_nr >= existing->cruft_packs.nr)
> + BUG("too many cruft packs (found %"PRIuMAX", but knew "
> + "of %"PRIuMAX")",
> + (uintmax_t)existing_cruft_nr + 1,
> + (uintmax_t)existing->cruft_packs.nr);
> + existing_cruft[existing_cruft_nr++] = p;
> + }
> +
> + QSORT(existing_cruft, existing_cruft_nr, existing_cruft_pack_cmp);
> +
> + for (i = 0; i < existing_cruft_nr; i++) {
> + off_t proposed;
This should also be `size_t` given that `st_add` returns `size_t` and
not `off_t`.
> + p = existing_cruft[i];
> + proposed = st_add(total_size, p->pack_size);
> +
> + if (proposed <= max_size) {
> + total_size = proposed;
> + fprintf(in, "-%s\n", pack_basename(p));
> + } else {
> + retain_cruft_pack(existing, p);
> + fprintf(in, "%s\n", pack_basename(p));
> + }
It's a bit funny that we re-check whether we have exceeded the maximum
size in subsequente iterations once we hit the limit, but it arguably
makes the logic a bit simpler.
> + }
> +
> + for (i = 0; i < existing->non_kept_packs.nr; i++)
> + fprintf(in, "-%s.pack\n",
> + existing->non_kept_packs.items[i].string);
> +
> + strbuf_release(&buf);
> +}
> +
> static int write_cruft_pack(const struct pack_objects_args *args,
> const char *destination,
> const char *pack_prefix,
> @@ -846,10 +944,18 @@ static int write_cruft_pack(const struct pack_objects_args *args,
> in = xfdopen(cmd.in, "w");
> for_each_string_list_item(item, names)
> fprintf(in, "%s-%s.pack\n", pack_prefix, item->string);
> - for_each_string_list_item(item, &existing->non_kept_packs)
> - fprintf(in, "-%s.pack\n", item->string);
> - for_each_string_list_item(item, &existing->cruft_packs)
> - fprintf(in, "-%s.pack\n", item->string);
> + if (args->max_pack_size && !cruft_expiration) {
> + unsigned long max_pack_size;
> + if (!git_parse_ulong(args->max_pack_size, &max_pack_size))
> + return error(_("could not parse --cruft-max-size: '%s'"),
> + args->max_pack_size);
> + collapse_small_cruft_packs(in, max_pack_size, existing);
> + } else {
> + for_each_string_list_item(item, &existing->non_kept_packs)
> + fprintf(in, "-%s.pack\n", item->string);
> + for_each_string_list_item(item, &existing->cruft_packs)
> + fprintf(in, "-%s.pack\n", item->string);
> + }
If I understand correctly, we only collapse small cruft packs in case
we're not expiring any objects at the same time. Is there an inherent
reason why? I would imagine that it can indeed be useful to expire
objects contained in cruft packs and then have git-repack(1) recombine
whatever is left into larger packs.
If the reason is basically "it's complicated" then that is fine with me,
we can still implement the functionality at a later point in time. But
until then I think that we should let callers know that the two options
are incompatible with each other by producing an error when both are
passed.
Patrick
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