Re: [PATCH v4 11/13] pack-bitmap.c: keep track of each layer's type bitmaps

> @@ -81,6 +81,24 @@ struct bitmap_index {
>  	struct ewah_bitmap *blobs;
>  	struct ewah_bitmap *tags;
>  
> +	/*
> +	 * Type index arrays when this bitmap is associated with an
> +	 * incremental multi-pack index chain.
> +	 *
> +	 * If n is the number of unique layers in the MIDX chain, then
> +	 * commits_all[n-1] is this structs 'commits' field,
> +	 * commits_all[n-2] is the commits field of this bitmap's
> +	 * 'base', and so on.
> +	 *
> +	 * When either associated either with a non-incremental MIDX, or
> +	 * a single packfile, these arrays each contain a single
> +	 * element.
> +	 */
> +	struct ewah_bitmap **commits_all;
> +	struct ewah_bitmap **trees_all;
> +	struct ewah_bitmap **blobs_all;
> +	struct ewah_bitmap **tags_all;

> -static int load_bitmap(struct repository *r, struct bitmap_index *bitmap_git)
> +static void load_all_type_bitmaps(struct bitmap_index *bitmap_git)
> +{
> +	struct bitmap_index *curr = bitmap_git;
> +	size_t i = bitmap_git->base_nr;
> +
> +	ALLOC_ARRAY(bitmap_git->commits_all, bitmap_git->base_nr + 1);
> +	ALLOC_ARRAY(bitmap_git->trees_all, bitmap_git->base_nr + 1);
> +	ALLOC_ARRAY(bitmap_git->blobs_all, bitmap_git->base_nr + 1);
> +	ALLOC_ARRAY(bitmap_git->tags_all, bitmap_git->base_nr + 1);
> +
> +	while (curr) {
> +		bitmap_git->commits_all[i] = curr->commits;
> +		bitmap_git->trees_all[i] = curr->trees;
> +		bitmap_git->blobs_all[i] = curr->blobs;
> +		bitmap_git->tags_all[i] = curr->tags;
> +
> +		curr = curr->base;
> +		if (curr && !i)
> +			BUG("unexpected number of bitmap layers, expected %"PRIu32,
> +			    bitmap_git->base_nr + 1);
> +		i -= 1;
> +	}
> +}