1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>http::read (2 of 4 overloads)</title> 5<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../index.html" title="Chapter 1. Boost.Beast"> 8<link rel="up" href="../boost__beast__http__read.html" title="http::read"> 9<link rel="prev" href="overload1.html" title="http::read (1 of 4 overloads)"> 10<link rel="next" href="overload3.html" title="http::read (3 of 4 overloads)"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="overload1.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost__beast__http__read.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload3.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="beast.ref.boost__beast__http__read.overload2"></a><a class="link" href="overload2.html" title="http::read (2 of 4 overloads)">http::read 28 (2 of 4 overloads)</a> 29</h5></div></div></div> 30<p> 31 Read a complete message from a stream using a parser. 32 </p> 33<h6> 34<a name="beast.ref.boost__beast__http__read.overload2.h0"></a> 35 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload2.synopsis"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__http__read.overload2.synopsis">Synopsis</a> 36 </h6> 37<p> 38 Defined in header <code class="literal"><<a href="../../../../../../../boost/beast/http/read.hpp" target="_top">boost/beast/http/read.hpp</a>></code> 39 </p> 40<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> 41 <span class="keyword">class</span> <a href="../../../../../../../doc/html/boost_asio/reference/SyncReadStream.html" target="_top"><span class="emphasis"><em>SyncReadStream</em></span></a><span class="special">,</span> 42 <span class="keyword">class</span> <a class="link" href="../../concepts/DynamicBuffer.html" title="DynamicBuffer"><span class="emphasis"><em>DynamicBuffer</em></span></a><span class="special">,</span> 43 <span class="keyword">bool</span> <span class="identifier">isRequest</span><span class="special">></span> 44<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> 45<span class="identifier">read</span><span class="special">(</span> 46 <span class="identifier">SyncReadStream</span><span class="special">&</span> <span class="identifier">stream</span><span class="special">,</span> 47 <span class="identifier">DynamicBuffer</span><span class="special">&</span> <span class="identifier">buffer</span><span class="special">,</span> 48 <span class="identifier">basic_parser</span><span class="special"><</span> <span class="identifier">isRequest</span> <span class="special">>&</span> <span class="identifier">parser</span><span class="special">,</span> 49 <span class="identifier">error_code</span><span class="special">&</span> <span class="identifier">ec</span><span class="special">);</span> 50</pre> 51<h6> 52<a name="beast.ref.boost__beast__http__read.overload2.h1"></a> 53 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload2.description"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__http__read.overload2.description">Description</a> 54 </h6> 55<p> 56 This function is used to read a complete message from a stream into an 57 instance of <a class="link" href="../boost__beast__http__basic_parser.html" title="http::basic_parser"><code class="computeroutput"><span class="identifier">basic_parser</span></code></a>. The call will block 58 until one of the following conditions is true: 59 </p> 60<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 61<li class="listitem"> 62 <a class="link" href="../boost__beast__http__basic_parser/is_done.html" title="http::basic_parser::is_done"><code class="computeroutput"><span class="identifier">basic_parser</span><span class="special">::</span><span class="identifier">is_done</span></code></a> returns <code class="computeroutput"><span class="keyword">true</span></code> 63 </li> 64<li class="listitem"> 65 An error occurs. 66 </li> 67</ul></div> 68<p> 69 This operation is implemented in terms of one or more calls to the stream's 70 <code class="computeroutput"><span class="identifier">read_some</span></code> function. The 71 implementation may read additional bytes from the stream that lie past 72 the end of the message being read. These additional bytes are stored in 73 the dynamic buffer, which must be preserved for subsequent reads. If the 74 end of file error is received while reading from the stream, then the error 75 returned from this function will be: 76 </p> 77<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 78<li class="listitem"> 79 <a class="link" href="../boost__beast__http__error.html" title="http::error"><code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">end_of_stream</span></code></a> 80 if no bytes were parsed, or 81 </li> 82<li class="listitem"> 83 <a class="link" href="../boost__beast__http__error.html" title="http::error"><code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">partial_message</span></code></a> 84 if any bytes were parsed but the message was incomplete, otherwise: 85 </li> 86<li class="listitem"> 87 A successful result. The next attempt to read will return <a class="link" href="../boost__beast__http__error.html" title="http::error"><code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">end_of_stream</span></code></a> 88 </li> 89</ul></div> 90<h6> 91<a name="beast.ref.boost__beast__http__read.overload2.h2"></a> 92 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload2.parameters"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__http__read.overload2.parameters">Parameters</a> 93 </h6> 94<div class="informaltable"><table class="table"> 95<colgroup> 96<col> 97<col> 98</colgroup> 99<thead><tr> 100<th> 101 <p> 102 Name 103 </p> 104 </th> 105<th> 106 <p> 107 Description 108 </p> 109 </th> 110</tr></thead> 111<tbody> 112<tr> 113<td> 114 <p> 115 <code class="computeroutput"><span class="identifier">stream</span></code> 116 </p> 117 </td> 118<td> 119 <p> 120 The stream from which the data is to be read. The type must meet 121 the <span class="emphasis"><em>SyncReadStream</em></span> requirements. 122 </p> 123 </td> 124</tr> 125<tr> 126<td> 127 <p> 128 <code class="computeroutput"><span class="identifier">buffer</span></code> 129 </p> 130 </td> 131<td> 132 <p> 133 Storage for additional bytes read by the implementation from 134 the stream. This is both an input and an output parameter; on 135 entry, the parser will be presented with any remaining data in 136 the dynamic buffer's readable bytes sequence first. The type 137 must meet the <span class="emphasis"><em>DynamicBuffer</em></span> requirements. 138 </p> 139 </td> 140</tr> 141<tr> 142<td> 143 <p> 144 <code class="computeroutput"><span class="identifier">parser</span></code> 145 </p> 146 </td> 147<td> 148 <p> 149 The parser to use. 150 </p> 151 </td> 152</tr> 153<tr> 154<td> 155 <p> 156 <code class="computeroutput"><span class="identifier">ec</span></code> 157 </p> 158 </td> 159<td> 160 <p> 161 Set to the error, if any occurred. 162 </p> 163 </td> 164</tr> 165</tbody> 166</table></div> 167<h6> 168<a name="beast.ref.boost__beast__http__read.overload2.h3"></a> 169 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload2.return_value"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__http__read.overload2.return_value">Return 170 Value</a> 171 </h6> 172<p> 173 The number of bytes transferred from the stream. 174 </p> 175<h6> 176<a name="beast.ref.boost__beast__http__read.overload2.h4"></a> 177 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload2.remarks"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__http__read.overload2.remarks">Remarks</a> 178 </h6> 179<p> 180 The function returns the total number of bytes transferred from the stream. 181 This may be zero for the case where there is sufficient pre-existing message 182 data in the dynamic buffer. The implementation will call <a class="link" href="../boost__beast__http__basic_parser/eager/overload1.html" title="http::basic_parser::eager (1 of 2 overloads)"><code class="computeroutput"><span class="identifier">basic_parser</span><span class="special">::</span><span class="identifier">eager</span></code></a> with the value <code class="computeroutput"><span class="keyword">true</span></code> on the parser passed in. 183 </p> 184</div> 185<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 186<td align="left"></td> 187<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Vinnie 188 Falco<p> 189 Distributed under the Boost Software License, Version 1.0. (See accompanying 190 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 191 </p> 192</div></td> 193</tr></table> 194<hr> 195<div class="spirit-nav"> 196<a accesskey="p" href="overload1.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost__beast__http__read.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload3.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 197</div> 198</body> 199</html> 200
