Re: [PATCH 1/3] packed_git: convert pack_local flag into generic bit mask

From: Shawn O. Pearce <spearce@spearce.org>
Date: Nov 3, 2008, 16:12 UTC
Message-ID: <20081103161202.GJ15463@spearce.org>
In-Reply-To: <6141358.1225643400587.JavaMail.teamon@b303.teamon.com>

drafnel@gmail.com wrote:

> This is in preparation for adding a flag indicating whether a .keep file is
> present.

Good idea.

Show 10 quoted lines

> diff --git a/cache.h b/cache.h
> index b0edbf9..0cb9350 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -679,12 +679,15 @@ extern struct packed_git {
>  	int index_version;
>  	time_t mtime;
>  	int pack_fd;
> -	int pack_local;
> +	unsigned int flags;

Hmm, isn't this a smaller change to make?

- int pack_local; + unsigned pack_local:1;

Then later you can do:

- unsigned pack_local:1; + unsigned pack_local:1, + pack_keep:1;

and the compiler handles all the bitmask stuff for you?

In general in git.git we like to use the struct bitmask stuff when possible as the code is easier to follow. We only use explicit mask constants and mask operations when the data is being stored on disk or written over the network and we need to ensure it is consistent across compilers. But for in-core only stuff, struct bitmasks are easier.

-- 
Shawn.