Re: [4/5] Add option for hardlinkable cache of extracted blobs

[Petr Baudis <pasky@ucw.cz>]

Dear diary, on Sun, Apr 17, 2005 at 05:35:19PM CEST, I got a letter
where Daniel Barkalow <barkalow@iabervon.org> told me that...
> Index: checkout-cache.c
> ===================================================================
> --- 157b46ce1d82b3579e2e1258927b0d9bdbc033ab/checkout-cache.c  (mode:100644 sha1:5d3028df0a45329e45fff2006719c9267adeb946)
> +++ 08f7700831e056ad710af69f91e3a8a705b6b2b1/checkout-cache.c  (mode:100644 sha1:338588259e17dd235fdc7db759d770004a760e15)
> @@ -67,6 +71,80 @@
>  	return fd;
>  }
>  
> +#ifdef HARDLINK_CACHE
> +
> +/*
> + * NOTE! This returns a statically allocated buffer, so you have to be
> + * careful about using it. Do a "strdup()" if you need to save the
> + * filename.
> + */
> +char *sha1_blob_cache_file_name(const unsigned char *sha1)
> +{
..code basically identical with sha1_file_name()..
> +}

You can guess what would I like you to do. ;-)

> +
> +static int write_entry(struct cache_entry *ce)
> +{
> +	int fd;
> +	void *new;
> +	unsigned long size;
> +	long wrote;
> +	char type[20];
> +	char *cache_name;
> +	struct stat st;
> +
> +	cache_name = sha1_blob_cache_file_name(ce->sha1);
> +
> +	if (stat(cache_name, &st)) {
..basically cut'n'paste of non-hardlinking write_entry()..

BTW, I'd just use access(F_OK) instead of stat() it I don't care about
the file's stat at all anyway.

> +	}
> +	if (link(cache_name, ce->name)) {
> +		if (errno == ENOENT) {
> +			create_directories(ce->name);
> +			link(cache_name, ce->name);
> +		}
> +	}
> +	return 0;
> +}

I think it would be better to have this as hardlink_entry() and
write_entry() to take the file name to write the entry to. Then you
should explicitly multiplex in checkout_cache() between what you do.

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor