diff options
author | DongHun Kwak <dh0128.kwak@samsung.com> | 2017-09-13 11:08:07 +0900 |
---|---|---|
committer | DongHun Kwak <dh0128.kwak@samsung.com> | 2017-09-13 11:09:00 +0900 |
commit | b5c87084afaef42b2d058f68091be31988a6a874 (patch) | |
tree | adef9a65870a41181687e11d57fdf98e7629de3c /doc/html/boost_asio/reference/async_read/overload2.html | |
parent | 34bd32e225e2a8a94104489b31c42e5801cc1f4a (diff) | |
download | boost-b5c87084afaef42b2d058f68091be31988a6a874.tar.gz boost-b5c87084afaef42b2d058f68091be31988a6a874.tar.bz2 boost-b5c87084afaef42b2d058f68091be31988a6a874.zip |
Imported Upstream version 1.64.0upstream/1.64.0
Change-Id: Id9212edd016dd55f21172c427aa7894d1d24148b
Signed-off-by: DongHun Kwak <dh0128.kwak@samsung.com>
Diffstat (limited to 'doc/html/boost_asio/reference/async_read/overload2.html')
-rw-r--r-- | doc/html/boost_asio/reference/async_read/overload2.html | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/doc/html/boost_asio/reference/async_read/overload2.html b/doc/html/boost_asio/reference/async_read/overload2.html new file mode 100644 index 0000000000..5fb0efa6cd --- /dev/null +++ b/doc/html/boost_asio/reference/async_read/overload2.html @@ -0,0 +1,158 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>async_read (2 of 4 overloads)</title> +<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> +<link rel="home" href="../../../boost_asio.html" title="Boost.Asio"> +<link rel="up" href="../async_read.html" title="async_read"> +<link rel="prev" href="overload1.html" title="async_read (1 of 4 overloads)"> +<link rel="next" href="overload3.html" title="async_read (3 of 4 overloads)"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> +<td align="center"><a href="../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="overload1.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../async_read.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.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> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_asio.reference.async_read.overload2"></a><a class="link" href="overload2.html" title="async_read (2 of 4 overloads)">async_read + (2 of 4 overloads)</a> +</h4></div></div></div> +<p> + Start an asynchronous operation to read a certain amount of data from a + stream. + </p> +<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> + <span class="keyword">typename</span> <a class="link" href="../AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a><span class="special">,</span> + <span class="keyword">typename</span> <a class="link" href="../MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a><span class="special">,</span> + <span class="keyword">typename</span> <span class="identifier">CompletionCondition</span><span class="special">,</span> + <span class="keyword">typename</span> <a class="link" href="../ReadHandler.html" title="Read handler requirements">ReadHandler</a><span class="special">></span> +<a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.return_type_of_an_initiating_function"><span class="emphasis"><em>void-or-deduced</em></span></a> <span class="identifier">async_read</span><span class="special">(</span> + <span class="identifier">AsyncReadStream</span> <span class="special">&</span> <span class="identifier">s</span><span class="special">,</span> + <span class="keyword">const</span> <span class="identifier">MutableBufferSequence</span> <span class="special">&</span> <span class="identifier">buffers</span><span class="special">,</span> + <span class="identifier">CompletionCondition</span> <span class="identifier">completion_condition</span><span class="special">,</span> + <span class="identifier">ReadHandler</span> <span class="identifier">handler</span><span class="special">);</span> +</pre> +<p> + This function is used to asynchronously read a certain number of bytes + of data from a stream. The function call always returns immediately. The + asynchronous operation will continue until one of the following conditions + is true: + </p> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + The supplied buffers are full. That is, the bytes transferred is equal + to the sum of the buffer sizes. + </li> +<li class="listitem"> + The completion_condition function object returns 0. + </li> +</ul></div> +<h6> +<a name="boost_asio.reference.async_read.overload2.h0"></a> + <span class="phrase"><a name="boost_asio.reference.async_read.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.async_read.overload2.parameters">Parameters</a> + </h6> +<div class="variablelist"> +<p class="title"><b></b></p> +<dl class="variablelist"> +<dt><span class="term">s</span></dt> +<dd><p> + The stream from which the data is to be read. The type must support + the AsyncReadStream concept. + </p></dd> +<dt><span class="term">buffers</span></dt> +<dd><p> + One or more buffers into which the data will be read. The sum of + the buffer sizes indicates the maximum number of bytes to read from + the stream. Although the buffers object may be copied as necessary, + ownership of the underlying memory blocks is retained by the caller, + which must guarantee that they remain valid until the handler is + called. + </p></dd> +<dt><span class="term">completion_condition</span></dt> +<dd> +<p> + The function object to be called to determine whether the read operation + is complete. The signature of the function object must be: +</p> +<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">completion_condition</span><span class="special">(</span> + <span class="comment">// Result of latest async_read_some operation.</span> + <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">// Number of bytes transferred so far.</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">bytes_transferred</span> +<span class="special">);</span> +</pre> +<p> + A return value of 0 indicates that the read operation is complete. + A non-zero return value indicates the maximum number of bytes to + be read on the next call to the stream's async_read_some function. + </p> +</dd> +<dt><span class="term">handler</span></dt> +<dd> +<p> + The handler to be called when the read operation completes. Copies + will be made of the handler as required. The function signature of + the handler must be: +</p> +<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span> + <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> + + <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 copied into the</span> + <span class="comment">// buffers. If an error occurred,</span> + <span class="comment">// this will be the number of</span> + <span class="comment">// bytes successfully transferred</span> + <span class="comment">// prior to the error.</span> +<span class="special">);</span> +</pre> +<p> + Regardless of whether the asynchronous operation completes immediately + or not, the handler will not be invoked from within this function. + Invocation of the handler will be performed in a manner equivalent + to using <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">post</span><span class="special">()</span></code>. + </p> +</dd> +</dl> +</div> +<h6> +<a name="boost_asio.reference.async_read.overload2.h1"></a> + <span class="phrase"><a name="boost_asio.reference.async_read.overload2.example"></a></span><a class="link" href="overload2.html#boost_asio.reference.async_read.overload2.example">Example</a> + </h6> +<p> + To read into a single data buffer use the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput"><span class="identifier">buffer</span></code></a> function as follows: + </p> +<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">async_read</span><span class="special">(</span><span class="identifier">s</span><span class="special">,</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">data</span><span class="special">,</span> <span class="identifier">size</span><span class="special">),</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">transfer_at_least</span><span class="special">(</span><span class="number">32</span><span class="special">),</span> + <span class="identifier">handler</span><span class="special">);</span> +</pre> +<p> + See the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput"><span class="identifier">buffer</span></code></a> + documentation for information on reading into multiple buffers in one go, + and how to use it with arrays, boost::array or std::vector. + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2017 Christopher M. Kohlhoff<p> + 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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="overload1.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../async_read.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.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> +</div> +</body> +</html> |