Re: Unresolved issues

On Mon, 19 Feb 2007, Junio C Hamano wrote:

Well, we could actually just do that in stages.

We might start off with just saying "unlike .gitignore", we only support one top-level ".gitattributes" file. That makes the problem space much simpler, and then we can have code like

	enum file_type {
		FILE_AUTO,
		FILE_BINARY,
		FILE_TEXT
	};

	static enum file_type get_file_type(const char *pathname)
	{
		static int has_initialized = 0;

		if (!has_initialized) {
			has_initialized = 1;
			read_file_attributes_file();
		}
		... check the filename against our attribute rules ..
	}

which would be fairly straightforward, and efficient.

It gets more complicated with per-directory attributes files, because then you need to either open those files *all* the time (stupid and expensive if you have thousands of files and hundreds of directories), or you need to have some way to cache just the ones you need.

(In fact, it might be perfectly fine to have just a *single* cache, which is keyed on the dirname of the pathname: if the dirname changes, just throw the cache away, and read it in from all the subdirectories leading to that directory - you'd still re-read stuff, but all the common cases will walk the directory structure in a nice pattern, so you'd have a very simple cache that actually gets good cache hit behaviour)

No, that would be pretty horrid. So just tell everybody that it's based on the working tree. I don't think it's likely to be a problem in practice.

		Linus