Re: [PATCH 09/21] tree_entry_interesting(): support depth limit

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 28, 2011, 20:40 UTC
Message-ID: <7vd3ngdaoa.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1292425376-14550-10-git-send-email-pclouds@gmail.com>

Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:

Show 14 quoted lines

>  static const char *get_mode(const char *str, unsigned int *modep)
> @@ -557,8 +558,13 @@ int tree_entry_interesting(const struct name_entry *entry,
>  	int pathlen, baselen = base->len;
>  	int never_interesting = -1;
>  
> -	if (!ps || !ps->nr)
> -		return 1;
> +	if (!ps->nr) {
> +		if (!ps->recursive || ps->max_depth == -1)
> +			return 1;
> +		return !!within_depth(base->buf, baselen,
> +				      !!S_ISDIR(entry->mode),
> +				      ps->max_depth);
> +	}

Back in 1d848f6 (tree_entry_interesting(): allow it to say "everything is interesting", 2007-03-21), a new return value "2" was introduced to allow this function to tell the caller that all the remaining entries in the tree object the caller is feeding the entries to this function _will_ match. This was to optimize away expensive pathspec matching done by this function.

In that version, "no pathspec" case wasn't changed to return 2 but still returned 1 ("I tell you that this does not match; call me with the next entry"). We could have changed it to return 2, but the overhead was only a call to a function that checks the number of pathspecs and was not so bad.

But shouldn't we start returning 2 by now? It is not that returning 1 was a more correct thing to do to begin with.

When depth check is in effect, the result depends on the mode of the entry, so we cannot short-circuit by returning 2, but at least we should do so when (max_depth == -1), no?