<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <HTML> <HEAD> <TITLE>Buffer Sizes</TITLE> <LINK REL="stylesheet" HREF="../../../../boost.css"> <LINK REL="stylesheet" HREF="../theme/iostreams.css"> </HEAD> <STYLE> DT A { /*text-decoration:none*/ } LI A { /*text-decoration:none;*/ font: 80% Verdana, Tahoma, Arial, Helvetica, sans-serif } </STYLE> <BODY> <!-- Begin Banner --> <H1 CLASS="title">Buffer Sizes</H1> <HR CLASS="banner"> <!-- End Banner --> <DL class="page-index"> <DT><A href="#overview">Overview</A></DT> <DT><A href="#headers">Headers</A></DT> <DT><A href="#synopsis">Synopsis</A></DT> </DL> <HR> <A NAME="overview"></A> <H2>Overview</H2> <P> The macros <CODE>BOOST_IOSTREAMS_DEFAULT_DEVICE_BUFFER_SIZE</CODE>, <CODE>BOOST_IOSTREAMS_DEFAULT_FILTER_BUFFER_SIZE</CODE> and <CODE>BOOST_IOSTREAMS_DEFAULT_PBACK_BUFFER_SIZE</CODE> can be used to configure the default sizes of buffers allocated by the Iostreams library when a <A HREF="../concepts/filter.html">Filter</A> or <A HREF="../concepts/device.html">Device</A> is attached to a <A HREF="../guide/generic_streams.html#stream_buffer"><CODE>stream_buffer</CODE></A> or <A HREF="../guide/generic_streams.html#stream"><CODE>stream</CODE></A>, or when it is added to a <A HREF="../classes/chain.html">chain</A>. </P> <P>The default values are subject to change in future versions of the Iostreams library.</P> <A NAME="headers"></A> <H2>Headers</H2> <DL class="page-index"> <DT><A CLASS="header" HREF="../../../../boost/iostreams/constants.hpp"><CODE><boost/iostreams/constants.hpp></CODE></A></DT> </DL> <A NAME="synopsis"></A> <H2>Synopsis</H2> <PRE CLASS='broken_ie'><SPAN CLASS='preprocessor'>#define</SPAN> BOOST_IOSTREAMS_DEFAULT_DEVICE_BUFFER_SIZE 4096 <SPAN CLASS='preprocessor'>#define</SPAN> BOOST_IOSTREAMS_DEFAULT_FILTER_BUFFER_SIZE 128 <SPAN CLASS='preprocessor'>#define</SPAN> BOOST_IOSTREAMS_DEFAULT_PBACK_BUFFER_SIZE 4</PRE> <!-- Begin Footer --> <P STYLE="margin-top:2em" CLASS="copyright">Revised 02 Feb 2008</P> <P CLASS="copyright">© Copyright 2008 <a href="http://www.coderage.com/" target="_top">CodeRage, LLC</a><br/>© Copyright 2004-2007 <a href="http://www.coderage.com/turkanis/" target="_top">Jonathan Turkanis</a><br/>Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <A HREF="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</A>) </P> <!-- End Footer --> </BODY>