17 Sep
2012
17 Sep
'12
3:24 p.m.
On 17 Sep 2012 at 15:19, Eric Smith wrote:
However, using it for in-memory symbol table lookup
isn't prior art
for using it to reduce disk access for filename lookup in a directory
on a storage medium, unless you can prove that it is an obvious
extension. You and I would probably think it is obvious.
Unfortunately the patent office "obviousness test", which is supposed
to be about a "person having ordinary skill in the art" (PHOSITA), as
actually applied seems only to consider persons that are complete
morons, for whom nothing is obvious.
My point is that we weren't idiots back then and devices were much
slower than they are today. Anything to improve performance would
have been welcome. For example, we briefly played with a filesystem
where allocation maps were kept on a sector for the storage on an
entire cylinder.
I would be *very* surprised if a file name table hash wasn't used
somewhere. Of course, you'd have billions of lines of code to
rummage through--if it said code hadn't been dumpstered ages ago.
Even so, where's the payoff for someone who might know where to look?
For example, there were FAT file systems 45 years ago (we didn't
call it a FAT, but rather an RBT for "record block table". One
improment we made over MS-DOS was that we swapped in the RBT chain
from disk for a file when a file was open).
--Chuck