Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!nih-csl!alw.nih.gov!kgorlen
From: kgorlen@alw.nih.gov (Keith Gorlen)
Newsgroups: comp.lang.c++
Subject: Re: Object/IO in NIHCL
Message-ID: <1547@nih-csl.nih.gov>
Date: 30 May 91 18:44:16 GMT
References: <1991May27.145953.115@bio.embnet.se>
Sender: news@nih-csl.nih.gov
Reply-To: kgorlen@alw.nih.gov (Keith Gorlen)
Organization: National Inst. of Health
Lines: 33

In article <1991May27.145953.115@bio.embnet.se>, sundvall@bio.embnet.se (Mats Sundvall) writes:
|> 
|> I am aboout to use the object IO mechanism in NIHCL 3.0 to be able to tranfer
|> data transactions between two machines. What I have not figured out yet is
|> if you transfer an object that contains pointers to other objects, are the
|> objects pointed to transfered as well.
|> 
|> 
|> class Transaction : public Object {
|> 
|> private:
|> 	int counter;
|> 	someObject	*typeofdata;
|> 	someOtherObject data;
|> 
|> ..
|> 
|> }
|> 
|> 
|> I do not want typeofdata to be transfered in every transaction because that
|> will be to much overhead.
|> 
|>  

You will have to write a storer() member function and a readFrom() constructor for class Transaction that will store/read instances of class Transaction.  These
functions can decide whether or not to store/read typeofdata.  Note that if you store a data structure that contains multiple Transaction instances, and some or all of these instances point to a shared instance of someObject, and your write the storer()/readFrom() for class Transaction to unconditionally store/read typeofdata, the shared someObject instances will be stored only once anyway.

-- 
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