Re: git gc & deleted branches

> "Brandon Casey" <drafnel@gmail.com> writes:
>
>> Is this invocation of pack-objects that you commented on necessary
>> though? This is the section that is replacing an existing pack file
>> with a newly created pack file of the same name...
>
> Yuck, I failed to see it in the context.  You are right.  This won't do
> anything I suspect.

> Perhaps we would want a new option --eject that causes pack-object write
> out unreachable packed objects in the loose format?  This would require a
> minor surgery to write_sha1_file() so that it won't pay attention to the
> return value of has_sha1_file(sha1), perhaps like this.
>
> This is a lunch-time hack and needs more serious work, such as fixing
> horrible "write_sha1_file_1" to something more sensible.
>
> Also it should add --eject as an independent and incompatible option
> instead of dropping --keep-unpacked support.
>
> ---
>
>  builtin-pack-objects.c |   56 ++++++++++++-----------------------------------
>  sha1_file.c            |    9 ++++++-
>  2 files changed, 22 insertions(+), 43 deletions(-)
>
> diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
> index 777f272..8240a4b 100644
> --- a/builtin-pack-objects.c
> +++ b/builtin-pack-objects.c
> @@ -1836,38 +1836,25 @@ struct in_pack {
>        struct in_pack_object *array;
>  };
>
> -static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
> +static void eject_object(struct object *obj)
>  {
> -       in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
> -       in_pack->array[in_pack->nr].object = object;
> -       in_pack->nr++;
> -}
> -
> -/*
> - * Compare the objects in the offset order, in order to emulate the
> - * "git-rev-list --objects" output that produced the pack originally.
> - */
> -static int ofscmp(const void *a_, const void *b_)
> -{
> -       struct in_pack_object *a = (struct in_pack_object *)a_;
> -       struct in_pack_object *b = (struct in_pack_object *)b_;
> +       enum object_type type;
> +       unsigned long size;
> +       void *data;
> +       unsigned char sha1[20];
>
> -       if (a->offset < b->offset)
> -               return -1;
> -       else if (a->offset > b->offset)
> -               return 1;
> -       else
> -               return hashcmp(a->object->sha1, b->object->sha1);
> +       data = read_sha1_file(obj->sha1, &type, &size);
> +       assert(data && type == obj->type);
> +       if (write_sha1_file_1(data, size, typename(type), sha1, 1))
> +               die("cannot eject packed object %s", sha1_to_hex(obj->sha1));
> +       assert(!memcmp(sha1, obj->sha1));
>  }
>
> -static void add_objects_in_unpacked_packs(struct rev_info *revs)
> +static void eject_objects_in_unpacked_packs(struct rev_info *revs)
>  {
>        struct packed_git *p;
> -       struct in_pack in_pack;
>        uint32_t i;
>
> -       memset(&in_pack, 0, sizeof(in_pack));
> -
>        for (p = packed_git; p; p = p->next) {
>                const unsigned char *sha1;
>                struct object *o;
> @@ -1881,28 +1868,15 @@ static void add_objects_in_unpacked_packs(struct rev_info *revs)
>                if (open_pack_index(p))
>                        die("cannot open pack index");
>
> -               ALLOC_GROW(in_pack.array,
> -                          in_pack.nr + p->num_objects,
> -                          in_pack.alloc);
> -
>                for (i = 0; i < p->num_objects; i++) {
>                        sha1 = nth_packed_object_sha1(p, i);
>                        o = lookup_unknown_object(sha1);
> -                       if (!(o->flags & OBJECT_ADDED))
> -                               mark_in_pack_object(o, p, &in_pack);
> +                       if (o->flags & OBJECT_ADDED)
> +                               continue;
>                        o->flags |= OBJECT_ADDED;
> +                       eject_object(o);
>                }
>        }
> -
> -       if (in_pack.nr) {
> -               qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
> -                     ofscmp);
> -               for (i = 0; i < in_pack.nr; i++) {
> -                       struct object *o = in_pack.array[i].object;
> -                       add_object_entry(o->sha1, o->type, "", 0);
> -               }
> -       }
> -       free(in_pack.array);
>  }
>
>  static void get_object_list(int ac, const char **av)
> @@ -1938,7 +1912,7 @@ static void get_object_list(int ac, const char **av)
>        traverse_commit_list(&revs, show_commit, show_object);
>
>        if (keep_unreachable)
> -               add_objects_in_unpacked_packs(&revs);
> +               eject_objects_in_unpacked_packs(&revs);
>  }
>
>  static int adjust_perm(const char *path, mode_t mode)
> diff --git a/sha1_file.c b/sha1_file.c
> index 3516777..ce3a661 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -2102,7 +2102,7 @@ int hash_sha1_file(const void *buf, unsigned long len, const char *type,
>        return 0;
>  }
>
> -int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
> +int write_sha1_file_1(void *buf, unsigned long len, const char *type, unsigned char *returnsha1, int refresh)
>  {
>        int size, ret;
>        unsigned char *compressed;
> @@ -2120,7 +2120,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
>        filename = sha1_file_name(sha1);
>        if (returnsha1)
>                hashcpy(returnsha1, sha1);
> -       if (has_sha1_file(sha1))
> +       if (!refresh && has_sha1_file(sha1))
>                return 0;
>        fd = open(filename, O_RDONLY);
>        if (fd >= 0) {
> @@ -2185,6 +2185,11 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
>        return move_temp_to_file(tmpfile, filename);
>  }
>
> +int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
> +{
> +       return write_sha1_file_1(buf, len, type, returnsha1, 0);
> +}
> +
>  /*
>  * We need to unpack and recompress the object for writing
>  * it out to a different file.
>