libs/beast/doc/html/beast/ref/boost__beast__buffered_read_stream/async_read_some.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>buffered_read_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&#160;1.&#160;Boost.Beast">
   8 <link rel="up" href="../boost__beast__buffered_read_stream.html" title="buffered_read_stream">
   9 <link rel="prev" href="../boost__beast__buffered_read_stream.html" title="buffered_read_stream">
  10 <link rel="next" href="async_write_some.html" title="buffered_read_stream::async_write_some">
  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="../boost__beast__buffered_read_stream.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost__beast__buffered_read_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="async_write_some.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__buffered_read_stream.async_read_some"></a><a class="link" href="async_read_some.html" title="buffered_read_stream::async_read_some">buffered_read_stream::async_read_some</a>
  28 </h5></div></div></div>
  29 <p>
  30           <a class="indexterm" name="idm45873513749408"></a>
  31 Start an asynchronous read.
  32         </p>
  33 <h6>
  34 <a name="beast.ref.boost__beast__buffered_read_stream.async_read_some.h0"></a>
  35           <span class="phrase"><a name="beast.ref.boost__beast__buffered_read_stream.async_read_some.synopsis"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__buffered_read_stream.async_read_some.synopsis">Synopsis</a>
  36         </h6>
  37 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
  38     <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>
  39     <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> <span class="identifier">net</span><span class="special">::</span><span class="identifier">default_completion_token_t</span><span class="special">&lt;</span><span class="identifier">executor_type</span><span class="special">&gt;&gt;</span>
  40 <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>
  41 <span class="identifier">async_read_some</span><span class="special">(</span>
  42     <span class="identifier">MutableBufferSequence</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">buffers</span><span class="special">,</span>
  43     <span class="identifier">ReadHandler</span><span class="special">&amp;&amp;</span> <span class="identifier">handler</span> <span class="special">=</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">default_completion_token_t</span><span class="special">&lt;</span> <span class="identifier">executor_type</span> <span class="special">&gt;{});</span>
  44 </pre>
  45 <h6>
  46 <a name="beast.ref.boost__beast__buffered_read_stream.async_read_some.h1"></a>
  47           <span class="phrase"><a name="beast.ref.boost__beast__buffered_read_stream.async_read_some.description"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__buffered_read_stream.async_read_some.description">Description</a>
  48         </h6>
  49 <p>
  50           This function is used to asynchronously read data from the stream. The
  51           function call always returns immediately.
  52         </p>
  53 <h6>
  54 <a name="beast.ref.boost__beast__buffered_read_stream.async_read_some.h2"></a>
  55           <span class="phrase"><a name="beast.ref.boost__beast__buffered_read_stream.async_read_some.parameters"></a></span><a class="link" href="async_read_some.html#beast.ref.boost__beast__buffered_read_stream.async_read_some.parameters">Parameters</a>
  56         </h6>
  57 <div class="informaltable"><table class="table">
  58 <colgroup>
  59 <col>
  60 <col>
  61 </colgroup>
  62 <thead><tr>
  63 <th>
  64                   <p>
  65                     Name
  66                   </p>
  67                 </th>
  68 <th>
  69                   <p>
  70                     Description
  71                   </p>
  72                 </th>
  73 </tr></thead>
  74 <tbody>
  75 <tr>
  76 <td>
  77                   <p>
  78                     <code class="computeroutput"><span class="identifier">buffers</span></code>
  79                   </p>
  80                 </td>
  81 <td>
  82                   <p>
  83                     One or more buffers into which the data will be read. Although
  84                     the buffers object may be copied as necessary, ownership of the
  85                     underlying memory blocks is retained by the caller, which must
  86                     guarantee that they remain valid until the handler is called.
  87                   </p>
  88                 </td>
  89 </tr>
  90 <tr>
  91 <td>
  92                   <p>
  93                     <code class="computeroutput"><span class="identifier">handler</span></code>
  94                   </p>
  95                 </td>
  96 <td>
  97                   <p>
  98                     The completion handler to invoke when the operation completes.
  99                     The implementation takes ownership of the handler by performing
 100                     a decay-copy. The equivalent function signature of the handler
 101                     must be:
 102                   </p>
 103 <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>
 104     <span class="identifier">error_code</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">error</span><span class="special">,</span>      <span class="comment">// result of operation</span>
 105     <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 transferred</span>
 106 <span class="special">);</span>
 107 </pre>
 108                 </td>
 109 </tr>
 110 </tbody>
 111 </table></div>
 112 <p>
 113           Regardless of whether the asynchronous operation completes immediately
 114           or not, the handler will not be invoked from within this function. Invocation
 115           of the handler will be performed in a manner equivalent to using <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">post</span></code>.
 116         </p>
 117 </div>
 118 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 119 <td align="left"></td>
 120 <td align="right"><div class="copyright-footer">Copyright &#169; 2016-2019 Vinnie
 121       Falco<p>
 122         Distributed under the Boost Software License, Version 1.0. (See accompanying
 123         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>)
 124       </p>
 125 </div></td>
 126 </tr></table>
 127 <hr>
 128 <div class="spirit-nav">
 129 <a accesskey="p" href="../boost__beast__buffered_read_stream.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost__beast__buffered_read_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="async_write_some.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
 130 </div>
 131 </body>
 132 </html>