Re: [PATCH 3/4] index-pack: Track the object_entry that creates each base_data

> If we free the data stored within a base_data we need the struct
> object_entry to get the data back again for use with another
> dependent delta.  Storing the object_entry* makes it simple to call
> get_data_from_pack() to recover the compressed information.
> 
> This however means we must add the missing baes object to the end

> of our packfile prior to calling resolve_delta() on each of the
> dependent deltas.  Adding the base first ensures we can read the
> base back from the pack we indexing, as if it had been included by
> the remote side.
> 
> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

> ---
>  index-pack.c |   18 ++++++++++++------
>  1 files changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/index-pack.c b/index-pack.c
> index 6c59fd3..7239e89 100644
> --- a/index-pack.c
> +++ b/index-pack.c
> @@ -29,6 +29,7 @@ union delta_base {
>  struct base_data {
>  	struct base_data *base;
>  	struct base_data *child;
> +	struct object_entry *obj;
>  	void *data;
>  	unsigned long size;
>  };
> @@ -476,6 +477,7 @@ static void resolve_delta(struct object_entry *delta_obj,
>  	sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
>  	nr_resolved_deltas++;
>  
> +	result.obj = delta_obj;
>  	link_base_data(base_obj, &result);
>  
>  	hashcpy(delta_base.sha1, delta_obj->idx.sha1);
> @@ -588,6 +590,7 @@ static void parse_pack_objects(unsigned char *sha1)
>  			continue;
>  		base_obj.data = get_data_from_pack(obj);
>  		base_obj.size = obj->size;
> +		base_obj.obj = obj;
>  		link_base_data(NULL, &base_obj);
>  
>  		if (ref)
> @@ -633,7 +636,8 @@ static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_c
>  	return size;
>  }
>  
> -static void append_obj_to_pack(const unsigned char *sha1, void *buf,
> +static struct object_entry *append_obj_to_pack(
> +			       const unsigned char *sha1, void *buf,
>  			       unsigned long size, enum object_type type)
>  {
>  	struct object_entry *obj = &objects[nr_objects++];
> @@ -654,6 +658,7 @@ static void append_obj_to_pack(const unsigned char *sha1, void *buf,
>  	obj[1].idx.offset = obj[0].idx.offset + n;
>  	obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
>  	hashcpy(obj->idx.sha1, sha1);
> +	return obj;
>  }
>  
>  static int delta_pos_compare(const void *_a, const void *_b)
> @@ -697,6 +702,12 @@ static void fix_unresolved_deltas(int nr_unresolved)
>  		base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
>  		if (!base_obj.data)
>  			continue;
> +
> +		if (check_sha1_signature(d->base.sha1, base_obj.data,
> +				base_obj.size, typename(type)))
> +			die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
> +		base_obj.obj = append_obj_to_pack(d->base.sha1, base_obj.data,
> +			base_obj.size, type);
>  		link_base_data(NULL, &base_obj);
>  
>  		find_delta_children(&d->base, &first, &last);
> @@ -706,11 +717,6 @@ static void fix_unresolved_deltas(int nr_unresolved)
>  				resolve_delta(child, &base_obj, type);
>  		}
>  
> -		if (check_sha1_signature(d->base.sha1, base_obj.data,
> -				base_obj.size, typename(type)))
> -			die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
> -		append_obj_to_pack(d->base.sha1, base_obj.data,
> -			base_obj.size, type);
>  		unlink_base_data(&base_obj);
>  		display_progress(progress, nr_resolved_deltas);
>  	}
> -- 
> 1.5.6.2.393.g45096
>