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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>17.7. asynchat — Asynchronous socket command/response handler — Python 2.7.18 documentation</title> <link rel="stylesheet" href="../_static/classic.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/language_data.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.18 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="18. 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Interprocess Communication and Networking</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="module-asynchat"> <span id="asynchat-asynchronous-socket-command-response-handler"></span><h1>17.7. <a class="reference internal" href="#module-asynchat" title="asynchat: Support for asynchronous command/response protocols."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asynchat</span></code></a> — Asynchronous socket command/response handler<a class="headerlink" href="#module-asynchat" title="Permalink to this headline">¶</a></h1> <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/2.7/Lib/asynchat.py">Lib/asynchat.py</a></p> <hr class="docutils" /> <p>This module builds on the <a class="reference internal" href="asyncore.html#module-asyncore" title="asyncore: A base class for developing asynchronous socket handling services."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncore</span></code></a> infrastructure, simplifying asynchronous clients and servers and making it easier to handle protocols whose elements are terminated by arbitrary strings, or are of variable length. <a class="reference internal" href="#module-asynchat" title="asynchat: Support for asynchronous command/response protocols."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asynchat</span></code></a> defines the abstract class <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a> that you subclass, providing implementations of the <code class="xref py py-meth docutils literal notranslate"><span class="pre">collect_incoming_data()</span></code> and <code class="xref py py-meth docutils literal notranslate"><span class="pre">found_terminator()</span></code> methods. It uses the same asynchronous loop as <a class="reference internal" href="asyncore.html#module-asyncore" title="asyncore: A base class for developing asynchronous socket handling services."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncore</span></code></a>, and the two types of channel, <a class="reference internal" href="asyncore.html#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a> and <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">asynchat.async_chat</span></code></a>, can freely be mixed in the channel map. Typically an <a class="reference internal" href="asyncore.html#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a> server channel generates new <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">asynchat.async_chat</span></code></a> channel objects as it receives incoming connection requests.</p> <dl class="class"> <dt id="asynchat.async_chat"> <em class="property">class </em><code class="descclassname">asynchat.</code><code class="descname">async_chat</code><a class="headerlink" href="#asynchat.async_chat" title="Permalink to this definition">¶</a></dt> <dd><p>This class is an abstract subclass of <a class="reference internal" href="asyncore.html#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a>. To make practical use of the code you must subclass <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a>, providing meaningful <a class="reference internal" href="#asynchat.async_chat.collect_incoming_data" title="asynchat.async_chat.collect_incoming_data"><code class="xref py py-meth docutils literal notranslate"><span class="pre">collect_incoming_data()</span></code></a> and <a class="reference internal" href="#asynchat.async_chat.found_terminator" title="asynchat.async_chat.found_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">found_terminator()</span></code></a> methods. The <a class="reference internal" href="asyncore.html#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a> methods can be used, although not all make sense in a message/response context.</p> <p>Like <a class="reference internal" href="asyncore.html#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a>, <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a> defines a set of events that are generated by an analysis of socket conditions after a <code class="xref c c-func docutils literal notranslate"><span class="pre">select()</span></code> call. Once the polling loop has been started the <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a> object’s methods are called by the event-processing framework with no action on the part of the programmer.</p> <p>Two class attributes can be modified, to improve performance, or possibly even to conserve memory.</p> <dl class="data"> <dt id="asynchat.async_chat.ac_in_buffer_size"> <code class="descname">ac_in_buffer_size</code><a class="headerlink" href="#asynchat.async_chat.ac_in_buffer_size" title="Permalink to this definition">¶</a></dt> <dd><p>The asynchronous input buffer size (default <code class="docutils literal notranslate"><span class="pre">4096</span></code>).</p> </dd></dl> <dl class="data"> <dt id="asynchat.async_chat.ac_out_buffer_size"> <code class="descname">ac_out_buffer_size</code><a class="headerlink" href="#asynchat.async_chat.ac_out_buffer_size" title="Permalink to this definition">¶</a></dt> <dd><p>The asynchronous output buffer size (default <code class="docutils literal notranslate"><span class="pre">4096</span></code>).</p> </dd></dl> <p>Unlike <a class="reference internal" href="asyncore.html#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a>, <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a> allows you to define a first-in-first-out queue (fifo) of <em>producers</em>. A producer need have only one method, <code class="xref py py-meth docutils literal notranslate"><span class="pre">more()</span></code>, which should return data to be transmitted on the channel. The producer indicates exhaustion (<em>i.e.</em> that it contains no more data) by having its <code class="xref py py-meth docutils literal notranslate"><span class="pre">more()</span></code> method return the empty string. At this point the <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a> object removes the producer from the fifo and starts using the next producer, if any. When the producer fifo is empty the <code class="xref py py-meth docutils literal notranslate"><span class="pre">handle_write()</span></code> method does nothing. You use the channel object’s <a class="reference internal" href="#asynchat.async_chat.set_terminator" title="asynchat.async_chat.set_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">set_terminator()</span></code></a> method to describe how to recognize the end of, or an important breakpoint in, an incoming transmission from the remote endpoint.</p> <p>To build a functioning <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a> subclass your input methods <a class="reference internal" href="#asynchat.async_chat.collect_incoming_data" title="asynchat.async_chat.collect_incoming_data"><code class="xref py py-meth docutils literal notranslate"><span class="pre">collect_incoming_data()</span></code></a> and <a class="reference internal" href="#asynchat.async_chat.found_terminator" title="asynchat.async_chat.found_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">found_terminator()</span></code></a> must handle the data that the channel receives asynchronously. The methods are described below.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.close_when_done"> <code class="descclassname">async_chat.</code><code class="descname">close_when_done</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.close_when_done" title="Permalink to this definition">¶</a></dt> <dd><p>Pushes a <code class="docutils literal notranslate"><span class="pre">None</span></code> on to the producer fifo. When this producer is popped off the fifo it causes the channel to be closed.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.collect_incoming_data"> <code class="descclassname">async_chat.</code><code class="descname">collect_incoming_data</code><span class="sig-paren">(</span><em>data</em><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.collect_incoming_data" title="Permalink to this definition">¶</a></dt> <dd><p>Called with <em>data</em> holding an arbitrary amount of received data. The default method, which must be overridden, raises a <a class="reference internal" href="exceptions.html#exceptions.NotImplementedError" title="exceptions.NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a> exception.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.discard_buffers"> <code class="descclassname">async_chat.</code><code class="descname">discard_buffers</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.discard_buffers" title="Permalink to this definition">¶</a></dt> <dd><p>In emergencies this method will discard any data held in the input and/or output buffers and the producer fifo.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.found_terminator"> <code class="descclassname">async_chat.</code><code class="descname">found_terminator</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.found_terminator" title="Permalink to this definition">¶</a></dt> <dd><p>Called when the incoming data stream matches the termination condition set by <a class="reference internal" href="#asynchat.async_chat.set_terminator" title="asynchat.async_chat.set_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">set_terminator()</span></code></a>. The default method, which must be overridden, raises a <a class="reference internal" href="exceptions.html#exceptions.NotImplementedError" title="exceptions.NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a> exception. The buffered input data should be available via an instance attribute.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.get_terminator"> <code class="descclassname">async_chat.</code><code class="descname">get_terminator</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.get_terminator" title="Permalink to this definition">¶</a></dt> <dd><p>Returns the current terminator for the channel.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.push"> <code class="descclassname">async_chat.</code><code class="descname">push</code><span class="sig-paren">(</span><em>data</em><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.push" title="Permalink to this definition">¶</a></dt> <dd><p>Pushes data on to the channel’s fifo to ensure its transmission. This is all you need to do to have the channel write the data out to the network, although it is possible to use your own producers in more complex schemes to implement encryption and chunking, for example.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.push_with_producer"> <code class="descclassname">async_chat.</code><code class="descname">push_with_producer</code><span class="sig-paren">(</span><em>producer</em><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.push_with_producer" title="Permalink to this definition">¶</a></dt> <dd><p>Takes a producer object and adds it to the producer fifo associated with the channel. When all currently-pushed producers have been exhausted the channel will consume this producer’s data by calling its <code class="xref py py-meth docutils literal notranslate"><span class="pre">more()</span></code> method and send the data to the remote endpoint.</p> </dd></dl> <dl class="method"> <dt id="asynchat.async_chat.set_terminator"> <code class="descclassname">async_chat.</code><code class="descname">set_terminator</code><span class="sig-paren">(</span><em>term</em><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.async_chat.set_terminator" title="Permalink to this definition">¶</a></dt> <dd><p>Sets the terminating condition to be recognized on the channel. <code class="docutils literal notranslate"><span class="pre">term</span></code> may be any of three types of value, corresponding to three different ways to handle incoming protocol data.</p> <table border="1" class="docutils"> <colgroup> <col width="20%" /> <col width="80%" /> </colgroup> <thead valign="bottom"> <tr class="row-odd"><th class="head">term</th> <th class="head">Description</th> </tr> </thead> <tbody valign="top"> <tr class="row-even"><td><em>string</em></td> <td>Will call <a class="reference internal" href="#asynchat.async_chat.found_terminator" title="asynchat.async_chat.found_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">found_terminator()</span></code></a> when the string is found in the input stream</td> </tr> <tr class="row-odd"><td><em>integer</em></td> <td>Will call <a class="reference internal" href="#asynchat.async_chat.found_terminator" title="asynchat.async_chat.found_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">found_terminator()</span></code></a> when the indicated number of characters have been received</td> </tr> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">None</span></code></td> <td>The channel continues to collect data forever</td> </tr> </tbody> </table> <p>Note that any data following the terminator will be available for reading by the channel after <a class="reference internal" href="#asynchat.async_chat.found_terminator" title="asynchat.async_chat.found_terminator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">found_terminator()</span></code></a> is called.</p> </dd></dl> <div class="section" id="asynchat-auxiliary-classes"> <h2>17.7.1. asynchat - Auxiliary Classes<a class="headerlink" href="#asynchat-auxiliary-classes" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="asynchat.fifo"> <em class="property">class </em><code class="descclassname">asynchat.</code><code class="descname">fifo</code><span class="sig-paren">(</span><span class="optional">[</span><em>list=None</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.fifo" title="Permalink to this definition">¶</a></dt> <dd><p>A <a class="reference internal" href="#asynchat.fifo" title="asynchat.fifo"><code class="xref py py-class docutils literal notranslate"><span class="pre">fifo</span></code></a> holding data which has been pushed by the application but not yet popped for writing to the channel. A <a class="reference internal" href="#asynchat.fifo" title="asynchat.fifo"><code class="xref py py-class docutils literal notranslate"><span class="pre">fifo</span></code></a> is a list used to hold data and/or producers until they are required. If the <em>list</em> argument is provided then it should contain producers or data items to be written to the channel.</p> <dl class="method"> <dt id="asynchat.fifo.is_empty"> <code class="descname">is_empty</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.fifo.is_empty" title="Permalink to this definition">¶</a></dt> <dd><p>Returns <code class="docutils literal notranslate"><span class="pre">True</span></code> if and only if the fifo is empty.</p> </dd></dl> <dl class="method"> <dt id="asynchat.fifo.first"> <code class="descname">first</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.fifo.first" title="Permalink to this definition">¶</a></dt> <dd><p>Returns the least-recently <a class="reference internal" href="#asynchat.fifo.push" title="asynchat.fifo.push"><code class="xref py py-meth docutils literal notranslate"><span class="pre">push()</span></code></a>ed item from the fifo.</p> </dd></dl> <dl class="method"> <dt id="asynchat.fifo.push"> <code class="descname">push</code><span class="sig-paren">(</span><em>data</em><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.fifo.push" title="Permalink to this definition">¶</a></dt> <dd><p>Adds the given data (which may be a string or a producer object) to the producer fifo.</p> </dd></dl> <dl class="method"> <dt id="asynchat.fifo.pop"> <code class="descname">pop</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asynchat.fifo.pop" title="Permalink to this definition">¶</a></dt> <dd><p>If the fifo is not empty, returns <code class="docutils literal notranslate"><span class="pre">True,</span> <span class="pre">first()</span></code>, deleting the popped item. Returns <code class="docutils literal notranslate"><span class="pre">False,</span> <span class="pre">None</span></code> for an empty fifo.</p> </dd></dl> </dd></dl> </div> <div class="section" id="asynchat-example"> <span id="id1"></span><h2>17.7.2. asynchat Example<a class="headerlink" href="#asynchat-example" title="Permalink to this headline">¶</a></h2> <p>The following partial example shows how HTTP requests can be read with <a class="reference internal" href="#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">async_chat</span></code></a>. A web server might create an <code class="xref py py-class docutils literal notranslate"><span class="pre">http_request_handler</span></code> object for each incoming client connection. Notice that initially the channel terminator is set to match the blank line at the end of the HTTP headers, and a flag indicates that the headers are being read.</p> <p>Once the headers have been read, if the request is of type POST (indicating that further data are present in the input stream) then the <code class="docutils literal notranslate"><span class="pre">Content-Length:</span></code> header is used to set a numeric terminator to read the right amount of data from the channel.</p> <p>The <code class="xref py py-meth docutils literal notranslate"><span class="pre">handle_request()</span></code> method is called once all relevant input has been marshalled, after setting the channel terminator to <code class="docutils literal notranslate"><span class="pre">None</span></code> to ensure that any extraneous data sent by the web client are ignored.</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">http_request_handler</span><span class="p">(</span><span class="n">asynchat</span><span class="o">.</span><span class="n">async_chat</span><span class="p">):</span> <span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">sock</span><span class="p">,</span> <span class="n">addr</span><span class="p">,</span> <span class="n">sessions</span><span class="p">,</span> <span class="n">log</span><span class="p">):</span> <span class="n">asynchat</span><span class="o">.</span><span class="n">async_chat</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">sock</span><span class="o">=</span><span class="n">sock</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">addr</span> <span class="o">=</span> <span class="n">addr</span> <span class="bp">self</span><span class="o">.</span><span class="n">sessions</span> <span class="o">=</span> <span class="n">sessions</span> <span class="bp">self</span><span class="o">.</span><span class="n">ibuffer</span> <span class="o">=</span> <span class="p">[]</span> <span class="bp">self</span><span class="o">.</span><span class="n">obuffer</span> <span class="o">=</span> <span class="s2">""</span> <span class="bp">self</span><span class="o">.</span><span class="n">set_terminator</span><span class="p">(</span><span class="s2">"</span><span class="se">\r\n\r\n</span><span class="s2">"</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">reading_headers</span> <span class="o">=</span> <span class="kc">True</span> <span class="bp">self</span><span class="o">.</span><span class="n">handling</span> <span class="o">=</span> <span class="kc">False</span> <span class="bp">self</span><span class="o">.</span><span class="n">cgi_data</span> <span class="o">=</span> <span class="kc">None</span> <span class="bp">self</span><span class="o">.</span><span class="n">log</span> <span class="o">=</span> <span class="n">log</span> <span class="k">def</span> <span class="nf">collect_incoming_data</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">data</span><span class="p">):</span> <span class="sd">"""Buffer the data"""</span> <span class="bp">self</span><span class="o">.</span><span class="n">ibuffer</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">data</span><span class="p">)</span> <span class="k">def</span> <span class="nf">found_terminator</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">reading_headers</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">reading_headers</span> <span class="o">=</span> <span class="kc">False</span> <span class="bp">self</span><span class="o">.</span><span class="n">parse_headers</span><span class="p">(</span><span class="s2">""</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">ibuffer</span><span class="p">))</span> <span class="bp">self</span><span class="o">.</span><span class="n">ibuffer</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">op</span><span class="o">.</span><span class="n">upper</span><span class="p">()</span> <span class="o">==</span> <span class="s2">"POST"</span><span class="p">:</span> <span class="n">clen</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">headers</span><span class="o">.</span><span class="n">getheader</span><span class="p">(</span><span class="s2">"content-length"</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">set_terminator</span><span class="p">(</span><span class="nb">int</span><span class="p">(</span><span class="n">clen</span><span class="p">))</span> <span class="k">else</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">handling</span> <span class="o">=</span> <span class="kc">True</span> <span class="bp">self</span><span class="o">.</span><span class="n">set_terminator</span><span class="p">(</span><span class="kc">None</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">handle_request</span><span class="p">()</span> <span class="k">elif</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">handling</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">set_terminator</span><span class="p">(</span><span class="kc">None</span><span class="p">)</span> <span class="c1"># browsers sometimes over-send</span> <span class="bp">self</span><span class="o">.</span><span class="n">cgi_data</span> <span class="o">=</span> <span class="n">parse</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">headers</span><span class="p">,</span> <span class="s2">""</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">ibuffer</span><span class="p">))</span> <span class="bp">self</span><span class="o">.</span><span class="n">handling</span> <span class="o">=</span> <span class="kc">True</span> <span class="bp">self</span><span class="o">.</span><span class="n">ibuffer</span> <span class="o">=</span> <span class="p">[]</span> <span class="bp">self</span><span class="o">.</span><span class="n">handle_request</span><span class="p">()</span> </pre></div> </div> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table of Contents</a></h3> <ul> <li><a class="reference internal" href="#">17.7. <code class="docutils literal notranslate"><span class="pre">asynchat</span></code> — Asynchronous socket command/response handler</a><ul> <li><a class="reference internal" href="#asynchat-auxiliary-classes">17.7.1. asynchat - Auxiliary Classes</a></li> <li><a class="reference internal" href="#asynchat-example">17.7.2. asynchat Example</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="asyncore.html" title="previous chapter">17.6. <code class="docutils literal notranslate"><span class="pre">asyncore</span></code> — Asynchronous socket handler</a></p> <h4>Next topic</h4> <p class="topless"><a href="netdata.html" title="next 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