Message 94

Re: tupleCmp

X-Added: With Flames (bblib $Revision: 1.4 $)
Return-path: <lw2j+@andrew.cmu.edu>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Received: from po0.andrew.cmu.edu via trymail for bb+academic.cs.15-721@andrew.cmu.edu
          ID </afs/andrew.cmu.edu/usr0/bb/Mailbox/4vp26Me00UdYQsCE4K>;
          Mon, 22 Oct 2001 09:39:36 -0400 (EDT)
Received: from mail1.andrew.cmu.edu (MAIL1.ANDREW.CMU.EDU [128.2.10.131])
        by po0.andrew.cmu.edu (8.9.3/8.9.3) with ESMTP id JAA14389
        for <bb+academic.cs.15-721@ams.andrew.cmu.edu>; Mon, 22 Oct 2001 09:39:36 -0400 (EDT)
Received: from po1.andrew.cmu.edu (PO1.ANDREW.CMU.EDU [128.2.10.101])
        by mail1.andrew.cmu.edu (8.12.0.Beta16/8.12.0.Beta16) with ESMTP id f9MDdYjc025991;
        Mon, 22 Oct 2001 09:39:34 -0400 (EDT)
Received: (from postman@localhost)
        by po1.andrew.cmu.edu (8.9.3/8.9.3) id JAA10911;
        Mon, 22 Oct 2001 09:39:33 -0400 (EDT)
Received: via switchmail; Mon, 22 Oct 2001 09:39:32 -0400 (EDT)
Received: from unix2.andrew.cmu.edu via qmail
          ID </afs/andrew.cmu.edu/service/mailqs/q001/QF.kvp261e00Uj:Q1cE8h>;
          Mon, 22 Oct 2001 09:39:13 -0400 (EDT)
Received: from unix2.andrew.cmu.edu via qmail
          ID </afs/andrew.cmu.edu/usr9/lw2j/.Outgoing/QF.svp261O00Uj:8BhXV5>;
          Mon, 22 Oct 2001 09:39:13 -0400 (EDT)
Received: from mms.4.60.Jul.16.2001.15.09.31.sun4.57.EzMail.2.0.CUILIB.3.45.SNAP.NOT.LINKED.unix2.andrew.cmu.edu.sun4x.57
          via MS.5.6.unix2.andrew.cmu.edu.sun4_57;
          Mon, 22 Oct 2001 09:39:13 -0400 (EDT)
Message-ID: <kvp261O00Uj_QBhXNP@andrew.cmu.edu>
Date: Mon, 22 Oct 2001 09:39:13 -0400 (EDT)
From: Leejay Wu <lw2j+@andrew.cmu.edu>
To: Neal Burns <nburns+@andrew.cmu.edu>
Subject: Re: tupleCmp
Cc: bboard-poster <post+academic.cs.15-721@andrew.cmu.edu>
In-Reply-To: <Pine.LNX.3.96L.1011021231440.1246C-100000@surreal>
References: <Pine.LNX.3.96L.1011021231440.1246C-100000@surreal>

Excerpts from academic.cs.15-721: 21-Oct-101 Re: tupleCmp by Neal
Burns@andrew.cmu.ed 
> Sorry to belabor this point, but where does tupleCmp get the sort order
> and key size? Are they globals set by the test code? Is it safe to just
> ignore this function and write our own?

sort_order is passed to the Sort constructor, and one of the 
things that function does is set sort.o's s_order to be that 
variable.  Ditto with key_size.  Since Sort uses tupleCmp 
via qsort, it can't accept any arguments besides two (void*) 
ptrs to the tuples, so it's done this way.
-- 
|   lw2j@cs.cmu.edu        | #include <0.0648g NaCl>     |              
|--------------------------|-----------------------------|  
|   #include <stddiscl.h>  | Spam returned to postmaster |