NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c++-part1/1096

Internet Message Format | 1996-08-06 | 1.9 KB

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From: [e-mail] (Herbert Thimm)
Newsgroups: comp.lang.c++,comp.lnag.c++.moderated
Subject: Re: cached output in c++
Date: Tue, 09 Jan 1996 02:40:22 GMT
Organization: Foundation for Research and Technology Hellas, FORTHnet
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Rob Stewart <[e-mail]> wrote:

>[e-mail] (Herbert Thimm) wrote:
>>Hello,
>>I am wondering, if C++ has build in buffered output (and input).

>Indeed, the iostreams library of classes do caching.  When you
>construct them, you can specify a streambuf-derived object
>to use for the buffer.  streambuf-derived classes permit
>you to provide the buffer they should use, so you can allocate
>whatever size buffer you need.

>Do note, however, that--at least in the implementations I've
>seen--streambuf doesn't split the buffer between input and
>output buffering.  Instead, it uses the one buffer one way or
>the other.  To get optimal buffering, you'd need to have an
>istream-derived object and an ostream-derived object
>separately operating on the same stream.  However, you'd also
>have to synchronize them such that changes made by the ostream
>invalidate the affected parts of the istream buffer.

Hello Rob and thanks for your answer,
I only need iostreams to work either as istreams or as ostreams, so
the usage of a common buffer does not seem to be a problem to me.
Do you know how to set the buffersizes? I am working with g++ 2.6.3 and
the documentation is not helping very much. (It says the details are
beeing worked out). Is there a way to set the cache size w/o getting
compiler/library dependend (that is, is the ANSI standard saying how to
do it?)

>--
>Robert Stewart        | My opinions are usually my own.
>Datalytics, Inc.
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