Re: [PATCH v5] fetch-pack.c: use oidset to check existence of loose object

> +struct loose_object_iter {
> +	struct oidset *loose_object_set;
> +	struct ref *refs;
> +};
> +
> +/*
> + *  If the number of refs is not larger than the number of loose objects,
> + *  this function stops inserting and returns false.
> + */
> +static int add_loose_objects_to_set(const struct object_id *oid,
> +				    const char *path,
> +				    void *data)
> +{
> +	struct loose_object_iter *iter = data;
> +	oidset_insert(iter->loose_object_set, oid);
> +	if (iter->refs == NULL)
> +		return 1;
> +
> +	iter->refs = iter->refs->next;
> +	return 0;
> +}

> @@ -719,16 +741,31 @@ static int everything_local(struct fetch_pack_args *args,
>  	int retval;
>  	int old_save_commit_buffer = save_commit_buffer;
>  	timestamp_t cutoff = 0;
> +	struct oidset loose_oid_set = OIDSET_INIT;
> +	int use_oidset = 0;
> +	struct loose_object_iter iter = {&loose_oid_set, *refs};
> +
> +	/* Enumerate all loose objects or know refs are not so many. */
> +	use_oidset = !for_each_loose_object(add_loose_objects_to_set,
> +					    &iter, 0);
>  
>  	save_commit_buffer = 0;
>  
>  	for (ref = *refs; ref; ref = ref->next) {
>  		struct object *o;
> +		unsigned int flags = OBJECT_INFO_QUICK;
>  
> -		if (!has_object_file_with_flags(&ref->old_oid,
> -						OBJECT_INFO_QUICK))
> -			continue;
> +		if (use_oidset &&
> +		    !oidset_contains(&loose_oid_set, &ref->old_oid)) {
> +			/*
> +			 * I know this does not exist in the loose form,
> +			 * so check if it exists in a non-loose form.
> +			 */
> +			flags |= OBJECT_INFO_IGNORE_LOOSE;
> +		}
>  
> +		if (!has_object_file_with_flags(&ref->old_oid, flags))
> +			continue;
>  		o = parse_object(&ref->old_oid);
>  		if (!o)
>  			continue;