Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!unmvax!ncar!tank!nucsrl!accuvax.nwu.edu!bob
From: bob@accuvax.nwu.edu (Bob Hablutzel)
Newsgroups: comp.sys.mac
Subject: Re: Re: Desktop Manager, what it is/isn't & suggestions
Message-ID: <10330100@accuvax.nwu.edu>
Date: 8 Dec 88 14:41:04 GMT
References: <1422@umbc3.UMD.EDU>
Organization: Northwestern U, Evanston IL, USA
Lines: 20

>>	It speeds up access to desktop information because it replaces the
>>normal desktop file which uses the Resource Manager and replaces it with
>>"B-Trees".

>I can't remember the last time I have questioned a posting from someone
>at Apple, but the two slips on HFS and floppies makes me reconsider this
>person's credibility.  Have you ever run Disk First Aid, typed COMMAND-S
>and then checked out an HFS volume (floppy or HD)?  It does several checks
>of "B-Trees," which leads me to believe that the Mac OS is already using
>B-Trees, so the question still stands - how does DM do it's stuff?

The MacOS _does_ already use B-Trees, but not for the desktop. Rather, the
extends file (which maps out where on a HFS disk a file resides) and the
catalog file (which contains information about the file) are B-Trees. The
Desktop file, however, is still a normal resource file, which means the 
resource manager bottlenecks apply. I guess what the DeskTop Manager INIT
does is replace the Desktop resource file with a Desktop B-Tree file, which
would be quite a bit faster, I think.

Bob Hablutzel	BOB@NUACC.ACNS.NWU.EDU