1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4 <TITLE>Buffer Sizes</TITLE> 5 <LINK REL="stylesheet" HREF="../../../../boost.css"> 6 <LINK REL="stylesheet" HREF="../theme/iostreams.css"> 7</HEAD> 8<STYLE> 9 DT A { /*text-decoration:none*/ } 10 LI A { /*text-decoration:none;*/ font: 80% Verdana, Tahoma, Arial, Helvetica, sans-serif } 11</STYLE> 12<BODY> 13 14<!-- Begin Banner --> 15 16 <H1 CLASS="title">Buffer Sizes</H1> 17 <HR CLASS="banner"> 18 19<!-- End Banner --> 20 21<DL class="page-index"> 22 <DT><A href="#overview">Overview</A></DT> 23 <DT><A href="#headers">Headers</A></DT> 24 <DT><A href="#synopsis">Synopsis</A></DT> 25</DL> 26 27<HR> 28 29<A NAME="overview"></A> 30<H2>Overview</H2> 31 32<P> 33 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>. 34</P> 35 36<P>The default values are subject to change in future versions of the Iostreams library.</P> 37 38<A NAME="headers"></A> 39<H2>Headers</H2> 40 41<DL class="page-index"> 42 <DT><A CLASS="header" HREF="../../../../boost/iostreams/constants.hpp"><CODE><boost/iostreams/constants.hpp></CODE></A></DT> 43</DL> 44 45<A NAME="synopsis"></A> 46<H2>Synopsis</H2> 47 48<PRE CLASS='broken_ie'><SPAN CLASS='preprocessor'>#define</SPAN> BOOST_IOSTREAMS_DEFAULT_DEVICE_BUFFER_SIZE 4096 49<SPAN CLASS='preprocessor'>#define</SPAN> BOOST_IOSTREAMS_DEFAULT_FILTER_BUFFER_SIZE 128 50<SPAN CLASS='preprocessor'>#define</SPAN> BOOST_IOSTREAMS_DEFAULT_PBACK_BUFFER_SIZE 4</PRE> 51 52<!-- Begin Footer --> 53 54 55<P CLASS="copyright">© Copyright 2008 <a href="http://www.coderage.com/" target="_top">CodeRage, LLC</a><br/>© Copyright 2004-2007 <a href="https://www.boost.org/users/people/jonathan_turkanis.html" 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>) 56</P> 57 58<!-- End Footer --> 59 60</BODY>