Re: Remove diff machinery dependency from read-cache

Linus Torvalds [off-list ref] writes:

This trivial cleanup results in pretty stunning file size differences. 
The diff machinery really is mostly used by just the builtin programs, and 
you have things like these trivial before-and-after numbers:

  -rwxr-xr-x 1 torvalds torvalds 1727420 2010-01-21 10:53 git-hash-object
  -rwxrwxr-x 1 torvalds torvalds  940265 2010-01-21 11:16 git-hash-object

Now, I'm not saying that 940kB is good either, but that's mostly all the 
debug information - you can see the real code with 'size':

   text	   data	    bss	    dec	    hex	filename
 418675	   3920	 127408	 550003	  86473	git-hash-object (before)
 230650	   2288	 111728	 344666	  5425a	git-hash-object (after)

ie we have a nice 24% size reduction from this trivial cleanup.

The patch itself to move add_files_to_cache() to builtin-add.c (or to its
own file) makes sense from the code placement POV, but if the goal is to
shrink the on-disk footprint, isn't an alternative approach be to make
hash-object built-in?  You can lose the whole 1.7M from the filesystem
footprint that way, no?