1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>ssl_stream::async_read_some</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__ssl_stream.html" title="ssl_stream"> 9<link rel="prev" href="read_some/overload2.html" title="ssl_stream::read_some (2 of 2 overloads)"> 10<link rel="next" href="../boost__beast__stable_async_base.html" title="stable_async_base"> 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="read_some/overload2.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost__beast__ssl_stream.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__stable_async_base.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__ssl_stream.async_read_some"></a><a class="link" href="async_read_some.html" title="ssl_stream::async_read_some">ssl_stream::async_read_some</a> 28</h5></div></div></div> 29<p> 30 <a class="indexterm" name="idm46057526371184"></a> 31 </p> 32<p> 33 Start an asynchronous read. 34 </p> 35<h6> 36<a name="beast.ref.boost__beast__ssl_stream.async_read_some.h0"></a> 37 <span class="phrase"><a name="beast.ref.boost__beast__ssl_stream.async_read_some.synopsis"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__ssl_stream.async_read_some.synopsis">Synopsis</a> 38 </h6> 39<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> 40 <span class="keyword">class</span> <a href="../../../../../../../doc/html/boost_asio/reference/MutableBufferSequence.html" target="_top"><span class="emphasis"><em>MutableBufferSequence</em></span></a><span class="special">,</span> 41 <span class="keyword">class</span> <a href="../../../../../../../doc/html/boost_asio/reference/ReadHandler.html" target="_top"><span class="emphasis"><em>ReadHandler</em></span></a><span class="special">></span> 42<a href="../../../../../../../doc/html/boost_asio/reference/asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type" target="_top"><span class="emphasis"><em>DEDUCED</em></span></a> 43<span class="identifier">async_read_some</span><span class="special">(</span> 44 <span class="identifier">MutableBufferSequence</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">buffers</span><span class="special">,</span> 45 <span class="identifier">BOOST_ASIO_MOVE_ARG</span><span class="special">(</span><span class="identifier">ReadHandler</span><span class="special">)</span> <span class="identifier">handler</span><span class="special">);</span> 46</pre> 47<h6> 48<a name="beast.ref.boost__beast__ssl_stream.async_read_some.h1"></a> 49 <span class="phrase"><a name="beast.ref.boost__beast__ssl_stream.async_read_some.description"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__ssl_stream.async_read_some.description">Description</a> 50 </h6> 51<p> 52 This function is used to asynchronously read one or more bytes of data 53 from the stream. The function call always returns immediately. 54 </p> 55<h6> 56<a name="beast.ref.boost__beast__ssl_stream.async_read_some.h2"></a> 57 <span class="phrase"><a name="beast.ref.boost__beast__ssl_stream.async_read_some.parameters"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__ssl_stream.async_read_some.parameters">Parameters</a> 58 </h6> 59<div class="informaltable"><table class="table"> 60<colgroup> 61<col> 62<col> 63</colgroup> 64<thead><tr> 65<th> 66 <p> 67 Name 68 </p> 69 </th> 70<th> 71 <p> 72 Description 73 </p> 74 </th> 75</tr></thead> 76<tbody> 77<tr> 78<td> 79 <p> 80 <code class="computeroutput"><span class="identifier">buffers</span></code> 81 </p> 82 </td> 83<td> 84 <p> 85 The buffers into which the data will be read. Although the buffers 86 object may be copied as necessary, ownership of the underlying 87 buffers is retained by the caller, which must guarantee that 88 they remain valid until the handler is called. 89 </p> 90 </td> 91</tr> 92<tr> 93<td> 94 <p> 95 <code class="computeroutput"><span class="identifier">handler</span></code> 96 </p> 97 </td> 98<td> 99 <p> 100 The handler to be called when the read operation completes. Copies 101 will be made of the handler as required. The equivalent function 102 signature of the handler must be: 103 </p> 104<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"> <span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span> 105 <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&</span> <span class="identifier">error</span><span class="special">,</span> <span class="comment">// Result of operation.</span> 106 <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">bytes_transferred</span> <span class="comment">// Number of bytes read.</span> 107<span class="special">);</span> 108</pre> 109 </td> 110</tr> 111</tbody> 112</table></div> 113<h6> 114<a name="beast.ref.boost__beast__ssl_stream.async_read_some.h3"></a> 115 <span class="phrase"><a name="beast.ref.boost__beast__ssl_stream.async_read_some.remarks"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__ssl_stream.async_read_some.remarks">Remarks</a> 116 </h6> 117<p> 118 The <code class="computeroutput"><span class="identifier">async_read_some</span></code> operation 119 may not read all of the requested number of bytes. Consider using the 120 <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">async_read</span></code> function if you need to ensure 121 that the requested amount of data is read before the asynchronous operation 122 completes. 123 </p> 124</div> 125<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 126<td align="left"></td> 127<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Vinnie 128 Falco<p> 129 Distributed under the Boost Software License, Version 1.0. (See accompanying 130 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>) 131 </p> 132</div></td> 133</tr></table> 134<hr> 135<div class="spirit-nav"> 136<a accesskey="p" href="read_some/overload2.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost__beast__ssl_stream.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__stable_async_base.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 137</div> 138</body> 139</html> 140
