1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>http::read (4 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="overload3.html" title="http::read (3 of 4 overloads)"> 10<link rel="next" href="../boost__beast__http__async_read.html" title="http::async_read"> 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="overload3.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="../boost__beast__http__async_read.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.overload4"></a><a class="link" href="overload4.html" title="http::read (4 of 4 overloads)">http::read 28 (4 of 4 overloads)</a> 29</h5></div></div></div> 30<p> 31 Read a complete message from a stream. 32 </p> 33<h6> 34<a name="beast.ref.boost__beast__http__read.overload4.h0"></a> 35 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload4.synopsis"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__http__read.overload4.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="keyword">class</span> <a class="link" href="../../concepts/Body.html" title="Body"><span class="emphasis"><em>Body</em></span></a><span class="special">,</span> 45 <span class="keyword">class</span> <a href="https://en.cppreference.com/w/cpp/named_req/Allocator" target="_top"><span class="emphasis"><em>Allocator</em></span></a><span class="special">></span> 46<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> 47<span class="identifier">read</span><span class="special">(</span> 48 <span class="identifier">SyncReadStream</span><span class="special">&</span> <span class="identifier">stream</span><span class="special">,</span> 49 <span class="identifier">DynamicBuffer</span><span class="special">&</span> <span class="identifier">buffer</span><span class="special">,</span> 50 <span class="identifier">message</span><span class="special"><</span> <span class="identifier">isRequest</span><span class="special">,</span> <span class="identifier">Body</span><span class="special">,</span> <span class="identifier">basic_fields</span><span class="special"><</span> <span class="identifier">Allocator</span> <span class="special">>>&</span> <span class="identifier">msg</span><span class="special">,</span> 51 <span class="identifier">error_code</span><span class="special">&</span> <span class="identifier">ec</span><span class="special">);</span> 52</pre> 53<h6> 54<a name="beast.ref.boost__beast__http__read.overload4.h1"></a> 55 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload4.description"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__http__read.overload4.description">Description</a> 56 </h6> 57<p> 58 This function is used to read a complete message from a stream into an 59 instance of <a class="link" href="../boost__beast__http__message.html" title="http::message"><code class="computeroutput"><span class="identifier">message</span></code></a>. The call will block until 60 one of the following conditions is true: 61 </p> 62<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 63<li class="listitem"> 64 The entire message is read in. 65 </li> 66<li class="listitem"> 67 An error occurs. 68 </li> 69</ul></div> 70<p> 71 This operation is implemented in terms of one or more calls to the stream's 72 <code class="computeroutput"><span class="identifier">read_some</span></code> function. The 73 implementation may read additional bytes from the stream that lie past 74 the end of the message being read. These additional bytes are stored in 75 the dynamic buffer, which must be preserved for subsequent reads. If the 76 end of file error is received while reading from the stream, then the error 77 returned from this function will be: 78 </p> 79<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 80<li class="listitem"> 81 <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> 82 if no bytes were parsed, or 83 </li> 84<li class="listitem"> 85 <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> 86 if any bytes were parsed but the message was incomplete, otherwise: 87 </li> 88<li class="listitem"> 89 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> 90 </li> 91</ul></div> 92<h6> 93<a name="beast.ref.boost__beast__http__read.overload4.h2"></a> 94 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload4.parameters"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__http__read.overload4.parameters">Parameters</a> 95 </h6> 96<div class="informaltable"><table class="table"> 97<colgroup> 98<col> 99<col> 100</colgroup> 101<thead><tr> 102<th> 103 <p> 104 Name 105 </p> 106 </th> 107<th> 108 <p> 109 Description 110 </p> 111 </th> 112</tr></thead> 113<tbody> 114<tr> 115<td> 116 <p> 117 <code class="computeroutput"><span class="identifier">stream</span></code> 118 </p> 119 </td> 120<td> 121 <p> 122 The stream from which the data is to be read. The type must meet 123 the <span class="emphasis"><em>SyncReadStream</em></span> requirements. 124 </p> 125 </td> 126</tr> 127<tr> 128<td> 129 <p> 130 <code class="computeroutput"><span class="identifier">buffer</span></code> 131 </p> 132 </td> 133<td> 134 <p> 135 Storage for additional bytes read by the implementation from 136 the stream. This is both an input and an output parameter; on 137 entry, the parser will be presented with any remaining data in 138 the dynamic buffer's readable bytes sequence first. The type 139 must meet the <span class="emphasis"><em>DynamicBuffer</em></span> requirements. 140 </p> 141 </td> 142</tr> 143<tr> 144<td> 145 <p> 146 <code class="computeroutput"><span class="identifier">msg</span></code> 147 </p> 148 </td> 149<td> 150 <p> 151 The container in which to store the message contents. This message 152 container should not have previous contents, otherwise the behavior 153 is undefined. The type must be meet the <span class="emphasis"><em>MoveAssignable</em></span> 154 and <span class="emphasis"><em>MoveConstructible</em></span> requirements. 155 </p> 156 </td> 157</tr> 158<tr> 159<td> 160 <p> 161 <code class="computeroutput"><span class="identifier">ec</span></code> 162 </p> 163 </td> 164<td> 165 <p> 166 Set to the error, if any occurred. 167 </p> 168 </td> 169</tr> 170</tbody> 171</table></div> 172<h6> 173<a name="beast.ref.boost__beast__http__read.overload4.h3"></a> 174 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload4.return_value"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__http__read.overload4.return_value">Return 175 Value</a> 176 </h6> 177<p> 178 The number of bytes transferred from the stream. 179 </p> 180<h6> 181<a name="beast.ref.boost__beast__http__read.overload4.h4"></a> 182 <span class="phrase"><a name="beast.ref.boost__beast__http__read.overload4.remarks"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__http__read.overload4.remarks">Remarks</a> 183 </h6> 184<p> 185 The function returns the total number of bytes transferred from the stream. 186 This may be zero for the case where there is sufficient pre-existing message 187 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. 188 </p> 189</div> 190<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 191<td align="left"></td> 192<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Vinnie 193 Falco<p> 194 Distributed under the Boost Software License, Version 1.0. (See accompanying 195 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>) 196 </p> 197</div></td> 198</tr></table> 199<hr> 200<div class="spirit-nav"> 201<a accesskey="p" href="overload3.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="../boost__beast__http__async_read.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 202</div> 203</body> 204</html> 205
