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| author | Sebastian Silva <sebastian@sugarlabs.org> | 2011-11-16 07:56:19 (GMT) |
|---|---|---|
| committer | Sebastian Silva <sebastian@sugarlabs.org> | 2011-11-16 07:56:19 (GMT) |
| commit | 82511a6fe2d29d50c1cdca4b2abb23ff681a1943 (patch) | |
| tree | ff6359d68287417abfaaf49e492e2630239e60c9 /studio/static/doc/flask-docs/patterns/caching.html | |
| parent | 61517139f02df2ce417f465dfabdbf5dbe8f4063 (diff) | |
Major improvements in IDE usability.
Diffstat (limited to 'studio/static/doc/flask-docs/patterns/caching.html')
| -rw-r--r-- | studio/static/doc/flask-docs/patterns/caching.html | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/studio/static/doc/flask-docs/patterns/caching.html b/studio/static/doc/flask-docs/patterns/caching.html deleted file mode 100644 index ed0d3c1..0000000 --- a/studio/static/doc/flask-docs/patterns/caching.html +++ /dev/null @@ -1,178 +0,0 @@ - -<!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="Content-Type" content="text/html; charset=utf-8" /> - - <title>Caching — Flask 0.8 documentation</title> - - <link rel="stylesheet" href="../_static/flasky.css" type="text/css" /> - <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> - - <script type="text/javascript"> - var DOCUMENTATION_OPTIONS = { - URL_ROOT: '../', - VERSION: '0.8', - COLLAPSE_INDEX: false, - FILE_SUFFIX: '.html', - HAS_SOURCE: true - }; - </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> - <link rel="top" title="Flask 0.8 documentation" href="../index.html" /> - <link rel="up" title="Patterns for Flask" href="index.html" /> - <link rel="next" title="View Decorators" href="viewdecorators.html" /> - <link rel="prev" title="Uploading Files" href="fileuploads.html" /> - - - <link rel="apple-touch-icon" href="../_static/touch-icon.png" /> - - <link media="only screen and (max-device-width: 480px)" href="../_static/small_flask.css" type= "text/css" rel="stylesheet" /> - - </head> - <body> - <div class="related"> - <h3>Navigation</h3> - <ul> - <li class="right" style="margin-right: 10px"> - <a href="../genindex.html" title="General Index" - accesskey="I">index</a></li> - <li class="right" > - <a href="viewdecorators.html" title="View Decorators" - accesskey="N">next</a> |</li> - <li class="right" > - <a href="fileuploads.html" title="Uploading Files" - accesskey="P">previous</a> |</li> - <li><a href="../index.html">Flask 0.8 documentation</a> »</li> - <li><a href="index.html" accesskey="U">Patterns for Flask</a> »</li> - </ul> - </div> - - <div class="document"> - <div class="documentwrapper"> - <div class="bodywrapper"> - <div class="body"> - - <div class="section" id="caching"> -<span id="caching-pattern"></span><h1>Caching<a class="headerlink" href="#caching" title="Permalink to this headline">¶</a></h1> -<p>When your application runs slow, throw some caches in. Well, at least -it’s the easiest way to speed up things. What does a cache do? Say you -have a function that takes some time to complete but the results would -still be good enough if they were 5 minutes old. So then the idea is that -you actually put the result of that calculation into a cache for some -time.</p> -<p>Flask itself does not provide caching for you, but Werkzeug, one of the -libraries it is based on, has some very basic cache support. It supports -multiple cache backends, normally you want to use a memcached server.</p> -<div class="section" id="setting-up-a-cache"> -<h2>Setting up a Cache<a class="headerlink" href="#setting-up-a-cache" title="Permalink to this headline">¶</a></h2> -<p>You create a cache object once and keep it around, similar to how -<a class="reference internal" href="../api.html#flask.Flask" title="flask.Flask"><tt class="xref py py-class docutils literal"><span class="pre">Flask</span></tt></a> objects are created. If you are using the -development server you can create a -<a class="reference external" href="http://werkzeug.pocoo.org/docs/contrib/cache/#werkzeug.contrib.cache.SimpleCache" title="(in Werkzeug v0.7)"><tt class="xref py py-class docutils literal"><span class="pre">SimpleCache</span></tt></a> object, that one is a simple -cache that keeps the item stored in the memory of the Python interpreter:</p> -<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">werkzeug.contrib.cache</span> <span class="kn">import</span> <span class="n">SimpleCache</span> -<span class="n">cache</span> <span class="o">=</span> <span class="n">SimpleCache</span><span class="p">()</span> -</pre></div> -</div> -<p>If you want to use memcached, make sure to have one of the memcache modules -supported (you get them from <a class="reference external" href="http://pypi.python.org/">PyPI</a>) and a -memcached server running somewhere. This is how you connect to such an -memcached server then:</p> -<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">werkzeug.contrib.cache</span> <span class="kn">import</span> <span class="n">MemcachedCache</span> -<span class="n">cache</span> <span class="o">=</span> <span class="n">MemcachedCache</span><span class="p">([</span><span class="s">'127.0.0.1:11211'</span><span class="p">])</span> -</pre></div> -</div> -<p>If you are using App Engine, you can connect to the App Engine memcache -server easily:</p> -<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">werkzeug.contrib.cache</span> <span class="kn">import</span> <span class="n">GAEMemcachedCache</span> -<span class="n">cache</span> <span class="o">=</span> <span class="n">GAEMemcachedCache</span><span class="p">()</span> -</pre></div> -</div> -</div> -<div class="section" id="using-a-cache"> -<h2>Using a Cache<a class="headerlink" href="#using-a-cache" title="Permalink to this headline">¶</a></h2> -<p>Now how can one use such a cache? There are two very important -operations: <a class="reference external" href="http://werkzeug.pocoo.org/docs/contrib/cache/#werkzeug.contrib.cache.BaseCache.get" title="(in Werkzeug v0.7)"><tt class="xref py py-meth docutils literal"><span class="pre">get()</span></tt></a> and -<a class="reference external" href="http://werkzeug.pocoo.org/docs/contrib/cache/#werkzeug.contrib.cache.BaseCache.set" title="(in Werkzeug v0.7)"><tt class="xref py py-meth docutils literal"><span class="pre">set()</span></tt></a>. This is how to use them:</p> -<p>To get an item from the cache call -<a class="reference external" href="http://werkzeug.pocoo.org/docs/contrib/cache/#werkzeug.contrib.cache.BaseCache.get" title="(in Werkzeug v0.7)"><tt class="xref py py-meth docutils literal"><span class="pre">get()</span></tt></a> with a string as key name. -If something is in the cache, it is returned. Otherwise that function -will return <cite>None</cite>:</p> -<div class="highlight-python"><div class="highlight"><pre><span class="n">rv</span> <span class="o">=</span> <span class="n">cache</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s">'my-item'</span><span class="p">)</span> -</pre></div> -</div> -<p>To add items to the cache, use the <a class="reference external" href="http://werkzeug.pocoo.org/docs/contrib/cache/#werkzeug.contrib.cache.BaseCache.set" title="(in Werkzeug v0.7)"><tt class="xref py py-meth docutils literal"><span class="pre">set()</span></tt></a> -method instead. The first argument is the key and the second the value -that should be set. Also a timeout can be provided after which the cache -will automatically remove item.</p> -<p>Here a full example how this looks like normally:</p> -<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">get_my_item</span><span class="p">():</span> - <span class="n">rv</span> <span class="o">=</span> <span class="n">cache</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s">'my-item'</span><span class="p">)</span> - <span class="k">if</span> <span class="n">rv</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span> - <span class="n">rv</span> <span class="o">=</span> <span class="n">calculate_value</span><span class="p">()</span> - <span class="n">cache</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="s">'my-item'</span><span class="p">,</span> <span class="n">rv</span><span class="p">,</span> <span class="n">timeout</span><span class="o">=</span><span class="mi">5</span> <span class="o">*</span> <span class="mi">60</span><span class="p">)</span> - <span class="k">return</span> <span class="n">rv</span> -</pre></div> -</div> -</div> -</div> - - - </div> - </div> - </div> - <div class="sphinxsidebar"> - <div class="sphinxsidebarwrapper"><p class="logo"><a href="../index.html"> - <img class="logo" src="../_static/flask.png" alt="Logo"/> -</a></p> - <h3><a href="../index.html">Table Of Contents</a></h3> - <ul> -<li><a class="reference internal" href="#">Caching</a><ul> -<li><a class="reference internal" href="#setting-up-a-cache">Setting up a Cache</a></li> -<li><a class="reference internal" href="#using-a-cache">Using a Cache</a></li> -</ul> -</li> -</ul> -<h3>Related Topics</h3> -<ul> - <li><a href="../index.html">Documentation overview</a><ul> - <li><a href="index.html">Patterns for Flask</a><ul> - <li>Previous: <a href="fileuploads.html" title="previous chapter">Uploading Files</a></li> - <li>Next: <a href="viewdecorators.html" title="next chapter">View Decorators</a></li> - </ul></li> - </ul></li> -</ul> - <h3>This Page</h3> - <ul class="this-page-menu"> - <li><a href="../_sources/patterns/caching.txt" - rel="nofollow">Show Source</a></li> - </ul> -<div id="searchbox" style="display: none"> - <h3>Quick search</h3> - <form class="search" action="../search.html" method="get"> - <input type="text" name="q" /> - <input type="submit" value="Go" /> - <input type="hidden" name="check_keywords" value="yes" /> - <input type="hidden" name="area" value="default" /> - </form> - <p class="searchtip" style="font-size: 90%"> - Enter search terms or a module, class or function name. - </p> -</div> -<script type="text/javascript">$('#searchbox').show(0);</script> - </div> - </div> - <div class="clearer"></div> - </div> - <div class="footer"> - © Copyright 2010, Armin Ronacher. - Created using <a href="http://sphinx.pocoo.org/">Sphinx</a>. - </div> - </body> -</html>
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