Re: [PATCH v2 5/9] pack-bitmap: introduce bitmap_walk_contains()

[Philip Oakley <philipoakley@iee.email>]

Hi Christian,
can I check one thing?

On 19/10/2019 11:35, Christian Couder wrote:
> From: Jeff King <peff@peff.net>
>
> We will use this helper function in a following commit to
> tell us if an object is packed.
>
> Signed-off-by: Jeff King <peff@peff.net>
> Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
> ---
>   pack-bitmap.c | 12 ++++++++++++
>   pack-bitmap.h |  3 +++
>   2 files changed, 15 insertions(+)
>
> diff --git a/pack-bitmap.c b/pack-bitmap.c
> index 016d0319fc..8a51302a1a 100644
> --- a/pack-bitmap.c
> +++ b/pack-bitmap.c
> @@ -826,6 +826,18 @@ int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
>   	return 0;
>   }
>   
> +int bitmap_walk_contains(struct bitmap_index *bitmap_git,
> +			 struct bitmap *bitmap, const struct object_id *oid)
> +{
> +	int idx;
Excuse my ignorance here...

For the case on Windows (int/long 32 bit), is this return value 
guaranteed to be less than 2GiB, i.e. not a memory offset?

I'm just thinking ahead to the resolution of the 4GiB file limit issue 
on Git-for-Windows (https://github.com/git-for-windows/git/pull/2179)

> +
> +	if (!bitmap)
> +		return 0;
> +
> +	idx = bitmap_position(bitmap_git, oid);
> +	return idx >= 0 && bitmap_get(bitmap, idx);
> +}
> +
>   void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
>   				 show_reachable_fn show_reachable)
>   {
> diff --git a/pack-bitmap.h b/pack-bitmap.h
> index 466c5afa09..6ab6033dbe 100644
> --- a/pack-bitmap.h
> +++ b/pack-bitmap.h
> @@ -3,6 +3,7 @@
>   
>   #include "ewah/ewok.h"
>   #include "khash.h"
> +#include "pack.h"
>   #include "pack-objects.h"
>   
>   struct commit;
> @@ -53,6 +54,8 @@ int reuse_partial_packfile_from_bitmap(struct bitmap_index *,
>   int rebuild_existing_bitmaps(struct bitmap_index *, struct packing_data *mapping,
>   			     kh_oid_map_t *reused_bitmaps, int show_progress);
>   void free_bitmap_index(struct bitmap_index *);
> +int bitmap_walk_contains(struct bitmap_index *,
> +			 struct bitmap *bitmap, const struct object_id *oid);
>   
>   /*
>    * After a traversal has been performed by prepare_bitmap_walk(), this can be
-- 
Philip