Edit File: caching.html
<!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 — Mako 1.1.0 Documentation </title> <!-- begin iterate through site-imported + sphinx environment css_files --> <link rel="stylesheet" href="_static/pygments.css" type="text/css" /> <link rel="stylesheet" href="_static/changelog.css" type="text/css" /> <link rel="stylesheet" href="_static/sphinx_paramlinks.css" type="text/css" /> <link rel="stylesheet" href="_static/docs.css" type="text/css" /> <!-- end iterate through site-imported + sphinx environment css_files --> <!-- begin layout.mako headers --> <link rel="index" title="Index" href="genindex.html" /> <link rel="search" title="Search" href="search.html" /> <link rel="top" title="Mako 1.1.0 Documentation" href="index.html" /> <link rel="next" title="Changelog" href="changelog.html" /> <link rel="prev" title="The Unicode Chapter" href="unicode.html" /> <!-- end layout.mako headers --> </head> <body> <div id="docs-container"> <div id="docs-header"> <h1>Mako 1.1.0 Documentation</h1> <div id="docs-search"> Search: <form class="search" action="search.html" method="get"> <input type="text" name="q" size="18" /> <input type="submit" value="Search" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <div id="docs-version-header"> Release: <span class="version-num">1.1.0</span> </div> </div> <div id="docs-top-navigation"> <div id="docs-top-page-control" class="docs-navigation-links"> <ul> <li>Prev: <a href="unicode.html" title="previous chapter">The Unicode Chapter</a> </li> <li>Next: <a href="changelog.html" title="next chapter">Changelog</a> </li> <li> <a href="index.html">Table of Contents</a> | <a href="genindex.html">Index</a> </li> </ul> </div> <div id="docs-navigation-banner"> <a href="index.html">Mako 1.1.0 Documentation</a> » Caching <h2> Caching </h2> </div> </div> <div id="docs-body-container"> <div id="docs-sidebar"> <div id="sidebar-banner"> </div> <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="#cache-arguments">Cache Arguments</a><ul> <li><a class="reference internal" href="#backend-specific-cache-arguments">Backend-Specific Cache Arguments</a></li> <li><a class="reference internal" href="#using-the-beaker-cache-backend">Using the Beaker Cache Backend</a></li> <li><a class="reference internal" href="#using-the-dogpile-cache-backend">Using the dogpile.cache Backend</a></li> </ul> </li> <li><a class="reference internal" href="#programmatic-cache-access">Programmatic Cache Access</a></li> <li><a class="reference internal" href="#cache-plugins">Cache Plugins</a><ul> <li><a class="reference internal" href="#guidelines-for-writing-cache-plugins">Guidelines for Writing Cache Plugins</a></li> </ul> </li> <li><a class="reference internal" href="#api-reference">API Reference</a></li> </ul> </li> </ul> <h4>Previous Topic</h4> <p> <a href="unicode.html" title="previous chapter">The Unicode Chapter</a> </p> <h4>Next Topic</h4> <p> <a href="changelog.html" title="next chapter">Changelog</a> </p> <h4>Quick Search</h4> <p> <form class="search" action="search.html" method="get"> <input type="text" name="q" size="18" /> <input type="submit" value="Search" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </p> </div> <div id="docs-body" class="withsidebar" > <div class="section" id="caching"> <span id="caching-toplevel"></span><h1>Caching<a class="headerlink" href="#caching" title="Permalink to this headline">¶</a></h1> <p>Any template or component can be cached using the <code class="docutils literal notranslate"><span class="pre">cache</span></code> argument to the <code class="docutils literal notranslate"><span class="pre"><%page></span></code>, <code class="docutils literal notranslate"><span class="pre"><%def></span></code> or <code class="docutils literal notranslate"><span class="pre"><%block></span></code> directives:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span><span class="nb">page</span> <span class="na">cached=</span><span class="s">"True"</span><span class="cp">/></span><span class="x"></span> <span class="x">template text</span></pre></div> </div> <p>The above template, after being executed the first time, will store its content within a cache that by default is scoped within memory. Subsequent calls to the template’s <a class="reference internal" href="usage.html#mako.template.Template.render" title="mako.template.Template.render"><code class="xref py py-meth docutils literal notranslate"><span class="pre">render()</span></code></a> method will return content directly from the cache. When the <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> object itself falls out of scope, its corresponding cache is garbage collected along with the template.</p> <p>The caching system requires that a cache backend be installed; this includes either the <a class="reference external" href="http://beaker.readthedocs.org/">Beaker</a> package or the <a class="reference external" href="http://dogpilecache.readthedocs.org">dogpile.cache</a>, as well as any other third-party caching libraries that feature Mako integration.</p> <p>By default, caching will attempt to make use of Beaker. To use dogpile.cache, the <code class="docutils literal notranslate"><span class="pre">cache_impl</span></code> argument must be set; see this argument in the section <a class="reference internal" href="#cache-arguments"><span class="std std-ref">Cache Arguments</span></a>.</p> <p>In addition to being available on the <code class="docutils literal notranslate"><span class="pre"><%page></span></code> tag, the caching flag and all its options can be used with the <code class="docutils literal notranslate"><span class="pre"><%def></span></code> tag as well:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span><span class="nb">def</span> <span class="na">name=</span><span class="s">"mycomp"</span> <span class="na">cached=</span><span class="s">"True"</span> <span class="na">cache_timeout=</span><span class="s">"60"</span><span class="cp">></span><span class="x"></span> <span class="x"> other text</span> <span class="cp"></%</span><span class="nb">def</span><span class="cp">></span><span class="x"></span></pre></div> </div> <p>… and equivalently with the <code class="docutils literal notranslate"><span class="pre"><%block></span></code> tag, anonymous or named:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span><span class="nb">block</span> <span class="na">cached=</span><span class="s">"True"</span> <span class="na">cache_timeout=</span><span class="s">"60"</span><span class="cp">></span><span class="x"></span> <span class="x"> other text</span> <span class="cp"></%</span><span class="nb">block</span><span class="cp">></span><span class="x"></span></pre></div> </div> <div class="section" id="cache-arguments"> <span id="id1"></span><h2>Cache Arguments<a class="headerlink" href="#cache-arguments" title="Permalink to this headline">¶</a></h2> <p>Mako has two cache arguments available on tags that are available in all cases. The rest of the arguments available are specific to a backend.</p> <p>The two generic tags arguments are:</p> <ul> <li><p><code class="docutils literal notranslate"><span class="pre">cached="True"</span></code> - enable caching for this <code class="docutils literal notranslate"><span class="pre"><%page></span></code>, <code class="docutils literal notranslate"><span class="pre"><%def></span></code>, or <code class="docutils literal notranslate"><span class="pre"><%block></span></code>.</p></li> <li><p><code class="docutils literal notranslate"><span class="pre">cache_key</span></code> - the “key” used to uniquely identify this content in the cache. Usually, this key is chosen automatically based on the name of the rendering callable (i.e. <code class="docutils literal notranslate"><span class="pre">body</span></code> when used in <code class="docutils literal notranslate"><span class="pre"><%page></span></code>, the name of the def when using <code class="docutils literal notranslate"><span class="pre"><%def></span></code>, the explicit or internally-generated name when using <code class="docutils literal notranslate"><span class="pre"><%block></span></code>). Using the <code class="docutils literal notranslate"><span class="pre">cache_key</span></code> parameter, the key can be overridden using a fixed or programmatically generated value.</p> <p>For example, here’s a page that caches any page which inherits from it, based on the filename of the calling template:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span><span class="nb">page</span> <span class="na">cached=</span><span class="s">"True"</span> <span class="na">cache_key=</span><span class="s">"${self.filename}"</span><span class="cp">/></span><span class="x"></span> <span class="cp">${</span><span class="nb">next</span><span class="o">.</span><span class="n">body</span><span class="p">()</span><span class="cp">}</span> <span class="cp">## rest of template</span><span class="x"></span></pre></div> </div> </li> </ul> <p>On a <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> or <a class="reference internal" href="usage.html#mako.lookup.TemplateLookup" title="mako.lookup.TemplateLookup"><code class="xref py py-class docutils literal notranslate"><span class="pre">TemplateLookup</span></code></a>, the caching can be configured using these arguments:</p> <ul> <li><p><code class="docutils literal notranslate"><span class="pre">cache_enabled</span></code> - Setting this to <code class="docutils literal notranslate"><span class="pre">False</span></code> will disable all caching functionality when the template renders. Defaults to <code class="docutils literal notranslate"><span class="pre">True</span></code>. e.g.:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">lookup</span> <span class="o">=</span> <span class="n">TemplateLookup</span><span class="p">(</span> <span class="n">directories</span><span class="o">=</span><span class="s1">'/path/to/templates'</span><span class="p">,</span> <span class="n">cache_enabled</span> <span class="o">=</span> <span class="bp">False</span> <span class="p">)</span></pre></div> </div> </li> <li><p><code class="docutils literal notranslate"><span class="pre">cache_impl</span></code> - The string name of the cache backend to use. This defaults to <code class="docutils literal notranslate"><span class="pre">'beaker'</span></code>, indicating that the ‘beaker’ backend will be used.</p></li> <li><p><code class="docutils literal notranslate"><span class="pre">cache_args</span></code> - A dictionary of cache parameters that will be consumed by the cache backend. See <a class="reference internal" href="#beaker-backend"><span class="std std-ref">Using the Beaker Cache Backend</span></a> and <a class="reference internal" href="#dogpile-cache-backend"><span class="std std-ref">Using the dogpile.cache Backend</span></a> for examples.</p></li> </ul> <div class="section" id="backend-specific-cache-arguments"> <h3>Backend-Specific Cache Arguments<a class="headerlink" href="#backend-specific-cache-arguments" title="Permalink to this headline">¶</a></h3> <p>The <code class="docutils literal notranslate"><span class="pre"><%page></span></code>, <code class="docutils literal notranslate"><span class="pre"><%def></span></code>, and <code class="docutils literal notranslate"><span class="pre"><%block></span></code> tags accept any named argument that starts with the prefix <code class="docutils literal notranslate"><span class="pre">"cache_"</span></code>. Those arguments are then packaged up and passed along to the underlying caching implementation, minus the <code class="docutils literal notranslate"><span class="pre">"cache_"</span></code> prefix.</p> <p>The actual arguments understood are determined by the backend.</p> <ul class="simple"> <li><p><a class="reference internal" href="#beaker-backend"><span class="std std-ref">Using the Beaker Cache Backend</span></a> - Includes arguments understood by Beaker.</p></li> <li><p><a class="reference internal" href="#dogpile-cache-backend"><span class="std std-ref">Using the dogpile.cache Backend</span></a> - Includes arguments understood by dogpile.cache.</p></li> </ul> </div> <div class="section" id="using-the-beaker-cache-backend"> <span id="beaker-backend"></span><h3>Using the Beaker Cache Backend<a class="headerlink" href="#using-the-beaker-cache-backend" title="Permalink to this headline">¶</a></h3> <p>When using Beaker, new implementations will want to make usage of <strong>cache regions</strong> so that cache configurations can be maintained externally to templates. These configurations live under named “regions” that can be referred to within templates themselves.</p> <div class="versionadded"> <p><span class="versionmodified added">New in version 0.6.0: </span>Support for Beaker cache regions.</p> </div> <p>For example, suppose we would like two regions. One is a “short term” region that will store content in a memory-based dictionary, expiring after 60 seconds. The other is a Memcached region, where values should expire in five minutes. To configure our <a class="reference internal" href="usage.html#mako.lookup.TemplateLookup" title="mako.lookup.TemplateLookup"><code class="xref py py-class docutils literal notranslate"><span class="pre">TemplateLookup</span></code></a>, first we get a handle to a <code class="xref py py-class docutils literal notranslate"><span class="pre">beaker.cache.CacheManager</span></code>:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">beaker.cache</span> <span class="kn">import</span> <span class="n">CacheManager</span> <span class="n">manager</span> <span class="o">=</span> <span class="n">CacheManager</span><span class="p">(</span><span class="n">cache_regions</span><span class="o">=</span><span class="p">{</span> <span class="s1">'short_term'</span><span class="p">:{</span> <span class="s1">'type'</span><span class="p">:</span> <span class="s1">'memory'</span><span class="p">,</span> <span class="s1">'expire'</span><span class="p">:</span> <span class="mi">60</span> <span class="p">},</span> <span class="s1">'long_term'</span><span class="p">:{</span> <span class="s1">'type'</span><span class="p">:</span> <span class="s1">'ext:memcached'</span><span class="p">,</span> <span class="s1">'url'</span><span class="p">:</span> <span class="s1">'127.0.0.1:11211'</span><span class="p">,</span> <span class="s1">'expire'</span><span class="p">:</span> <span class="mi">300</span> <span class="p">}</span> <span class="p">})</span> <span class="n">lookup</span> <span class="o">=</span> <span class="n">TemplateLookup</span><span class="p">(</span> <span class="n">directories</span><span class="o">=</span><span class="p">[</span><span class="s1">'/path/to/templates'</span><span class="p">],</span> <span class="n">module_directory</span><span class="o">=</span><span class="s1">'/path/to/modules'</span><span class="p">,</span> <span class="n">cache_impl</span><span class="o">=</span><span class="s1">'beaker'</span><span class="p">,</span> <span class="n">cache_args</span><span class="o">=</span><span class="p">{</span> <span class="s1">'manager'</span><span class="p">:</span><span class="n">manager</span> <span class="p">}</span> <span class="p">)</span></pre></div> </div> <p>Our templates can then opt to cache data in one of either region, using the <code class="docutils literal notranslate"><span class="pre">cache_region</span></code> argument. Such as using <code class="docutils literal notranslate"><span class="pre">short_term</span></code> at the <code class="docutils literal notranslate"><span class="pre"><%page></span></code> level:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span><span class="nb">page</span> <span class="na">cached=</span><span class="s">"True"</span> <span class="na">cache_region=</span><span class="s">"short_term"</span><span class="cp">></span> <span class="cp">## ...</span><span class="x"></span></pre></div> </div> <p>Or, <code class="docutils literal notranslate"><span class="pre">long_term</span></code> at the <code class="docutils literal notranslate"><span class="pre"><%block></span></code> level:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span><span class="nb">block</span> <span class="na">name=</span><span class="s">"header"</span> <span class="na">cached=</span><span class="s">"True"</span> <span class="na">cache_region=</span><span class="s">"long_term"</span><span class="cp">></span><span class="x"></span> <span class="x"> other text</span> <span class="cp"></%</span><span class="nb">block</span><span class="cp">></span><span class="x"></span></pre></div> </div> <p>The Beaker backend also works without regions. There are a variety of arguments that can be passed to the <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> dictionary, which are also allowable in templates via the <code class="docutils literal notranslate"><span class="pre"><%page></span></code>, <code class="docutils literal notranslate"><span class="pre"><%block></span></code>, and <code class="docutils literal notranslate"><span class="pre"><%def></span></code> tags specific to those sections. The values given override those specified at the <a class="reference internal" href="usage.html#mako.lookup.TemplateLookup" title="mako.lookup.TemplateLookup"><code class="xref py py-class docutils literal notranslate"><span class="pre">TemplateLookup</span></code></a> or <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> level.</p> <p>With the possible exception of <code class="docutils literal notranslate"><span class="pre">cache_timeout</span></code>, these arguments are probably better off staying at the template configuration level. Each argument specified as <code class="docutils literal notranslate"><span class="pre">cache_XYZ</span></code> in a template tag is specified without the <code class="docutils literal notranslate"><span class="pre">cache_</span></code> prefix in the <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> dictionary:</p> <ul class="simple"> <li><p><code class="docutils literal notranslate"><span class="pre">cache_timeout</span></code> - number of seconds in which to invalidate the cached data. After this timeout, the content is re-generated on the next call. Available as <code class="docutils literal notranslate"><span class="pre">timeout</span></code> in the <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> dictionary.</p></li> <li><p><code class="docutils literal notranslate"><span class="pre">cache_type</span></code> - type of caching. <code class="docutils literal notranslate"><span class="pre">'memory'</span></code>, <code class="docutils literal notranslate"><span class="pre">'file'</span></code>, <code class="docutils literal notranslate"><span class="pre">'dbm'</span></code>, or <code class="docutils literal notranslate"><span class="pre">'ext:memcached'</span></code> (note that the string <code class="docutils literal notranslate"><span class="pre">memcached</span></code> is also accepted by the dogpile.cache Mako plugin, though not by Beaker itself). Available as <code class="docutils literal notranslate"><span class="pre">type</span></code> in the <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> dictionary.</p></li> <li><p><code class="docutils literal notranslate"><span class="pre">cache_url</span></code> - (only used for <code class="docutils literal notranslate"><span class="pre">memcached</span></code> but required) a single IP address or a semi-colon separated list of IP address of memcache servers to use. Available as <code class="docutils literal notranslate"><span class="pre">url</span></code> in the <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> dictionary.</p></li> <li><p><code class="docutils literal notranslate"><span class="pre">cache_dir</span></code> - in the case of the <code class="docutils literal notranslate"><span class="pre">'file'</span></code> and <code class="docutils literal notranslate"><span class="pre">'dbm'</span></code> cache types, this is the filesystem directory with which to store data files. If this option is not present, the value of <code class="docutils literal notranslate"><span class="pre">module_directory</span></code> is used (i.e. the directory where compiled template modules are stored). If neither option is available an exception is thrown. Available as <code class="docutils literal notranslate"><span class="pre">dir</span></code> in the <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> dictionary.</p></li> </ul> </div> <div class="section" id="using-the-dogpile-cache-backend"> <span id="dogpile-cache-backend"></span><h3>Using the dogpile.cache Backend<a class="headerlink" href="#using-the-dogpile-cache-backend" title="Permalink to this headline">¶</a></h3> <p><a class="reference external" href="http://dogpilecache.readthedocs.org">dogpile.cache</a> is a new replacement for Beaker. It provides a modernized, slimmed down interface and is generally easier to use than Beaker. As of this writing it has not yet been released. dogpile.cache includes its own Mako cache plugin – see <code class="xref py py-mod docutils literal notranslate"><span class="pre">dogpile.cache.plugins.mako_cache</span></code> in the dogpile.cache documentation.</p> </div> </div> <div class="section" id="programmatic-cache-access"> <h2>Programmatic Cache Access<a class="headerlink" href="#programmatic-cache-access" title="Permalink to this headline">¶</a></h2> <p>The <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a>, as well as any template-derived <a class="reference internal" href="namespaces.html#mako.runtime.Namespace" title="mako.runtime.Namespace"><code class="xref py py-class docutils literal notranslate"><span class="pre">Namespace</span></code></a>, has an accessor called <code class="docutils literal notranslate"><span class="pre">cache</span></code> which returns the <a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a> object for that template. This object is a facade on top of the underlying <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> object, and provides some very rudimental capabilities, such as the ability to get and put arbitrary values:</p> <div class="highlight-mako notranslate"><div class="highlight"><pre><span></span><span class="cp"><%</span> <span class="n">local</span><span class="o">.</span><span class="n">cache</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="s2">"somekey"</span><span class="p">,</span> <span class="nb">type</span><span class="o">=</span><span class="s2">"memory"</span><span class="p">,</span> <span class="s2">"somevalue"</span><span class="p">)</span> <span class="cp">%></span><span class="x"></span></pre></div> </div> <p>Above, the cache associated with the <code class="docutils literal notranslate"><span class="pre">local</span></code> namespace is accessed and a key is placed within a memory cache.</p> <p>More commonly, the <code class="docutils literal notranslate"><span class="pre">cache</span></code> object is used to invalidate cached sections programmatically:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">template</span> <span class="o">=</span> <span class="n">lookup</span><span class="o">.</span><span class="n">get_template</span><span class="p">(</span><span class="s1">'/sometemplate.html'</span><span class="p">)</span> <span class="c1"># invalidate the "body" of the template</span> <span class="n">template</span><span class="o">.</span><span class="n">cache</span><span class="o">.</span><span class="n">invalidate_body</span><span class="p">()</span> <span class="c1"># invalidate an individual def</span> <span class="n">template</span><span class="o">.</span><span class="n">cache</span><span class="o">.</span><span class="n">invalidate_def</span><span class="p">(</span><span class="s1">'somedef'</span><span class="p">)</span> <span class="c1"># invalidate an arbitrary key</span> <span class="n">template</span><span class="o">.</span><span class="n">cache</span><span class="o">.</span><span class="n">invalidate</span><span class="p">(</span><span class="s1">'somekey'</span><span class="p">)</span></pre></div> </div> <p>You can access any special method or attribute of the <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> itself using the <a class="reference internal" href="#mako.cache.Cache.impl" title="mako.cache.Cache.impl"><code class="xref py py-attr docutils literal notranslate"><span class="pre">impl</span></code></a> attribute:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">template</span><span class="o">.</span><span class="n">cache</span><span class="o">.</span><span class="n">impl</span><span class="o">.</span><span class="n">do_something_special</span><span class="p">()</span></pre></div> </div> <p>Note that using implementation-specific methods will mean you can’t swap in a different kind of <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> implementation at a later time.</p> </div> <div class="section" id="cache-plugins"> <span id="id2"></span><h2>Cache Plugins<a class="headerlink" href="#cache-plugins" title="Permalink to this headline">¶</a></h2> <p>The mechanism used by caching can be plugged in using a <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> subclass. This class implements the rudimental methods Mako needs to implement the caching API. Mako includes the <a class="reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl" title="mako.ext.beaker_cache.BeakerCacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">BeakerCacheImpl</span></code></a> class to provide the default implementation. A <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> class is acquired by Mako using a <code class="docutils literal notranslate"><span class="pre">pkg_resources</span></code> entrypoint, using the name given as the <code class="docutils literal notranslate"><span class="pre">cache_impl</span></code> argument to <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> or <a class="reference internal" href="usage.html#mako.lookup.TemplateLookup" title="mako.lookup.TemplateLookup"><code class="xref py py-class docutils literal notranslate"><span class="pre">TemplateLookup</span></code></a>. This entry point can be installed via the standard <cite>setuptools</cite>/<code class="docutils literal notranslate"><span class="pre">setup()</span></code> procedure, underneath the <cite>EntryPoint</cite> group named <code class="docutils literal notranslate"><span class="pre">"mako.cache"</span></code>. It can also be installed at runtime via a convenience installer <a class="reference internal" href="#mako.cache.register_plugin" title="mako.cache.register_plugin"><code class="xref py py-func docutils literal notranslate"><span class="pre">register_plugin()</span></code></a> which accomplishes essentially the same task.</p> <p>An example plugin that implements a local dictionary cache:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">mako.cache</span> <span class="kn">import</span> <span class="n">Cacheimpl</span><span class="p">,</span> <span class="n">register_plugin</span> <span class="k">class</span> <span class="nc">SimpleCacheImpl</span><span class="p">(</span><span class="n">CacheImpl</span><span class="p">):</span> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">cache</span><span class="p">):</span> <span class="nb">super</span><span class="p">(</span><span class="n">SimpleCacheImpl</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="n">cache</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cache</span> <span class="o">=</span> <span class="p">{}</span> <span class="k">def</span> <span class="nf">get_or_create</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">,</span> <span class="n">creation_function</span><span class="p">,</span> <span class="o">**</span><span class="n">kw</span><span class="p">):</span> <span class="k">if</span> <span class="n">key</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cache</span><span class="p">:</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cache</span><span class="p">[</span><span class="n">key</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">_cache</span><span class="p">[</span><span class="n">key</span><span class="p">]</span> <span class="o">=</span> <span class="n">value</span> <span class="o">=</span> <span class="n">creation_function</span><span class="p">()</span> <span class="k">return</span> <span class="n">value</span> <span class="k">def</span> <span class="nf">set</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">,</span> <span class="n">value</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cache</span><span class="p">[</span><span class="n">key</span><span class="p">]</span> <span class="o">=</span> <span class="n">value</span> <span class="k">def</span> <span class="nf">get</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span> <span class="k">return</span> <span class="bp">self</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="n">key</span><span class="p">)</span> <span class="k">def</span> <span class="nf">invalidate</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cache</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="bp">None</span><span class="p">)</span> <span class="c1"># optional - register the class locally</span> <span class="n">register_plugin</span><span class="p">(</span><span class="s2">"simple"</span><span class="p">,</span> <span class="vm">__name__</span><span class="p">,</span> <span class="s2">"SimpleCacheImpl"</span><span class="p">)</span></pre></div> </div> <p>Enabling the above plugin in a template would look like:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">t</span> <span class="o">=</span> <span class="n">Template</span><span class="p">(</span><span class="s2">"mytemplate"</span><span class="p">,</span> <span class="nb">file</span><span class="o">=</span><span class="s2">"mytemplate.html"</span><span class="p">,</span> <span class="n">cache_impl</span><span class="o">=</span><span class="s1">'simple'</span><span class="p">)</span></pre></div> </div> <div class="section" id="guidelines-for-writing-cache-plugins"> <h3>Guidelines for Writing Cache Plugins<a class="headerlink" href="#guidelines-for-writing-cache-plugins" title="Permalink to this headline">¶</a></h3> <ul class="simple"> <li><p>The <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> is created on a per-<a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> basis. The class should ensure that only data for the parent <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> is persisted or returned by the cache methods. The actual <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> is available via the <code class="docutils literal notranslate"><span class="pre">self.cache.template</span></code> attribute. The <code class="docutils literal notranslate"><span class="pre">self.cache.id</span></code> attribute, which is essentially the unique modulename of the template, is a good value to use in order to represent a unique namespace of keys specific to the template.</p></li> <li><p>Templates only use the <a class="reference internal" href="#mako.cache.CacheImpl.get_or_create" title="mako.cache.CacheImpl.get_or_create"><code class="xref py py-meth docutils literal notranslate"><span class="pre">CacheImpl.get_or_create()</span></code></a> method in an implicit fashion. The <a class="reference internal" href="#mako.cache.CacheImpl.set" title="mako.cache.CacheImpl.set"><code class="xref py py-meth docutils literal notranslate"><span class="pre">CacheImpl.set()</span></code></a>, <a class="reference internal" href="#mako.cache.CacheImpl.get" title="mako.cache.CacheImpl.get"><code class="xref py py-meth docutils literal notranslate"><span class="pre">CacheImpl.get()</span></code></a>, and <a class="reference internal" href="#mako.cache.CacheImpl.invalidate" title="mako.cache.CacheImpl.invalidate"><code class="xref py py-meth docutils literal notranslate"><span class="pre">CacheImpl.invalidate()</span></code></a> methods are only used in response to direct programmatic access to the corresponding methods on the <a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a> object.</p></li> <li><p><a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> will be accessed in a multithreaded fashion if the <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> itself is used multithreaded. Care should be taken to ensure caching implementations are threadsafe.</p></li> <li><p>A library like <a class="reference external" href="http://pypi.python.org/pypi/dogpile.core">Dogpile</a>, which is a minimal locking system derived from Beaker, can be used to help implement the <a class="reference internal" href="#mako.cache.CacheImpl.get_or_create" title="mako.cache.CacheImpl.get_or_create"><code class="xref py py-meth docutils literal notranslate"><span class="pre">CacheImpl.get_or_create()</span></code></a> method in a threadsafe way that can maximize effectiveness across multiple threads as well as processes. <a class="reference internal" href="#mako.cache.CacheImpl.get_or_create" title="mako.cache.CacheImpl.get_or_create"><code class="xref py py-meth docutils literal notranslate"><span class="pre">CacheImpl.get_or_create()</span></code></a> is the key method used by templates.</p></li> <li><p>All arguments passed to <code class="docutils literal notranslate"><span class="pre">**kw</span></code> come directly from the parameters inside the <code class="docutils literal notranslate"><span class="pre"><%def></span></code>, <code class="docutils literal notranslate"><span class="pre"><%block></span></code>, or <code class="docutils literal notranslate"><span class="pre"><%page></span></code> tags directly, minus the <code class="docutils literal notranslate"><span class="pre">"cache_"</span></code> prefix, as strings, with the exception of the argument <code class="docutils literal notranslate"><span class="pre">cache_timeout</span></code>, which is passed to the plugin as the name <code class="docutils literal notranslate"><span class="pre">timeout</span></code> with the value converted to an integer. Arguments present in <code class="docutils literal notranslate"><span class="pre">cache_args</span></code> on <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> or <a class="reference internal" href="usage.html#mako.lookup.TemplateLookup" title="mako.lookup.TemplateLookup"><code class="xref py py-class docutils literal notranslate"><span class="pre">TemplateLookup</span></code></a> are passed directly, but are superseded by those present in the most specific template tag.</p></li> <li><p>The directory where <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> places module files can be acquired using the accessor <code class="docutils literal notranslate"><span class="pre">self.cache.template.module_directory</span></code>. This directory can be a good place to throw cache-related work files, underneath a prefix like <code class="docutils literal notranslate"><span class="pre">_my_cache_work</span></code> so that name conflicts with generated modules don’t occur.</p></li> </ul> </div> </div> <div class="section" id="api-reference"> <h2>API Reference<a class="headerlink" href="#api-reference" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="mako.cache.Cache"> <em class="property">class </em><code class="sig-prename descclassname">mako.cache.</code><code class="sig-name descname">Cache</code><span class="sig-paren">(</span><em class="sig-param">template</em>, <em class="sig-param">*args</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache" title="Permalink to this definition">¶</a></dt> <dd><p>Bases: <code class="xref py py-class docutils literal notranslate"><span class="pre">object</span></code></p> <p>Represents a data content cache made available to the module space of a specific <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> object.</p> <div class="versionadded"> <p><span class="versionmodified added">New in version 0.6: </span><a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a> by itself is mostly a container for a <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> object, which implements a fixed API to provide caching services; specific subclasses exist to implement different caching strategies. Mako includes a backend that works with the Beaker caching system. Beaker itself then supports a number of backends (i.e. file, memory, memcached, etc.)</p> </div> <p>The construction of a <a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a> is part of the mechanics of a <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a>, and programmatic access to this cache is typically via the <code class="xref py py-attr docutils literal notranslate"><span class="pre">Template.cache</span></code> attribute.</p> <dl class="method"> <dt id="mako.cache.Cache.get"> <code class="sig-name descname">get</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.get" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieve a value from the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.Cache.get.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.get.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.Cache.get.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.get.params.**kw">¶</a> – cache configuration arguments. The backend is configured using these arguments upon first request. Subsequent requests that use the same series of configuration values will use that same backend.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.get_or_create"> <code class="sig-name descname">get_or_create</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">creation_function</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.get_or_create" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieve a value from the cache, using the given creation function to generate a new value.</p> </dd></dl> <dl class="attribute"> <dt id="mako.cache.Cache.id"> <code class="sig-name descname">id</code><em class="property"> = None</em><a class="headerlink" href="#mako.cache.Cache.id" title="Permalink to this definition">¶</a></dt> <dd><p>Return the ‘id’ that identifies this cache.</p> <p>This is a value that should be globally unique to the <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> associated with this cache, and can be used by a caching system to name a local container for data specific to this template.</p> </dd></dl> <dl class="attribute"> <dt id="mako.cache.Cache.impl"> <code class="sig-name descname">impl</code><em class="property"> = None</em><a class="headerlink" href="#mako.cache.Cache.impl" title="Permalink to this definition">¶</a></dt> <dd><p>Provide the <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> in use by this <a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a>.</p> <p>This accessor allows a <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> with additional methods beyond that of <a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a> to be used programmatically.</p> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.invalidate"> <code class="sig-name descname">invalidate</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.invalidate" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate a value in the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.Cache.invalidate.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.invalidate.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.Cache.invalidate.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.invalidate.params.**kw">¶</a> – cache configuration arguments. The backend is configured using these arguments upon first request. Subsequent requests that use the same series of configuration values will use that same backend.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.invalidate_body"> <code class="sig-name descname">invalidate_body</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.invalidate_body" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate the cached content of the “body” method for this template.</p> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.invalidate_closure"> <code class="sig-name descname">invalidate_closure</code><span class="sig-paren">(</span><em class="sig-param">name</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.invalidate_closure" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate a nested <code class="docutils literal notranslate"><span class="pre"><%def></span></code> within this template.</p> <p>Caching of nested defs is a blunt tool as there is no management of scope – nested defs that use cache tags need to have names unique of all other nested defs in the template, else their content will be overwritten by each other.</p> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.invalidate_def"> <code class="sig-name descname">invalidate_def</code><span class="sig-paren">(</span><em class="sig-param">name</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.invalidate_def" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate the cached content of a particular <code class="docutils literal notranslate"><span class="pre"><%def></span></code> within this template.</p> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.put"> <code class="sig-name descname">put</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">value</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.put" title="Permalink to this definition">¶</a></dt> <dd><p>A synonym for <a class="reference internal" href="#mako.cache.Cache.set" title="mako.cache.Cache.set"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Cache.set()</span></code></a>.</p> <p>This is here for backwards compatibility.</p> </dd></dl> <dl class="method"> <dt id="mako.cache.Cache.set"> <code class="sig-name descname">set</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">value</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.Cache.set" title="Permalink to this definition">¶</a></dt> <dd><p>Place a value in the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.Cache.set.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.set.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.Cache.set.params.value"></span><strong>value</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.set.params.value">¶</a> – the value.</p></li> <li><p><span class="target" id="mako.cache.Cache.set.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.Cache.set.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="attribute"> <dt id="mako.cache.Cache.starttime"> <code class="sig-name descname">starttime</code><em class="property"> = None</em><a class="headerlink" href="#mako.cache.Cache.starttime" title="Permalink to this definition">¶</a></dt> <dd><p>Epochal time value for when the owning <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> was first compiled.</p> <p>A cache implementation may wish to invalidate data earlier than this timestamp; this has the effect of the cache for a specific <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> starting clean any time the <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> is recompiled, such as when the original template file changed on the filesystem.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="mako.cache.CacheImpl"> <em class="property">class </em><code class="sig-prename descclassname">mako.cache.</code><code class="sig-name descname">CacheImpl</code><span class="sig-paren">(</span><em class="sig-param">cache</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.CacheImpl" title="Permalink to this definition">¶</a></dt> <dd><p>Bases: <code class="xref py py-class docutils literal notranslate"><span class="pre">object</span></code></p> <p>Provide a cache implementation for use by <a class="reference internal" href="#mako.cache.Cache" title="mako.cache.Cache"><code class="xref py py-class docutils literal notranslate"><span class="pre">Cache</span></code></a>.</p> <dl class="method"> <dt id="mako.cache.CacheImpl.get"> <code class="sig-name descname">get</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.CacheImpl.get" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieve a value from the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.CacheImpl.get.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.get.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.CacheImpl.get.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.get.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="method"> <dt id="mako.cache.CacheImpl.get_or_create"> <code class="sig-name descname">get_or_create</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">creation_function</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.CacheImpl.get_or_create" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieve a value from the cache, using the given creation function to generate a new value.</p> <p>This function <em>must</em> return a value, either from the cache, or via the given creation function. If the creation function is called, the newly created value should be populated into the cache under the given key before being returned.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.CacheImpl.get_or_create.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.get_or_create.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.CacheImpl.get_or_create.params.creation_function"></span><strong>creation_function</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.get_or_create.params.creation_function">¶</a> – function that when called generates a new value.</p></li> <li><p><span class="target" id="mako.cache.CacheImpl.get_or_create.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.get_or_create.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="method"> <dt id="mako.cache.CacheImpl.invalidate"> <code class="sig-name descname">invalidate</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.CacheImpl.invalidate" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate a value in the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.CacheImpl.invalidate.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.invalidate.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.CacheImpl.invalidate.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.invalidate.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="attribute"> <dt id="mako.cache.CacheImpl.pass_context"> <code class="sig-name descname">pass_context</code><em class="property"> = False</em><a class="headerlink" href="#mako.cache.CacheImpl.pass_context" title="Permalink to this definition">¶</a></dt> <dd><p>If <code class="docutils literal notranslate"><span class="pre">True</span></code>, the <a class="reference internal" href="runtime.html#mako.runtime.Context" title="mako.runtime.Context"><code class="xref py py-class docutils literal notranslate"><span class="pre">Context</span></code></a> will be passed to <a class="reference internal" href="#mako.cache.CacheImpl.get_or_create" title="mako.cache.CacheImpl.get_or_create"><code class="xref py py-meth docutils literal notranslate"><span class="pre">get_or_create</span></code></a> as the name <code class="docutils literal notranslate"><span class="pre">'context'</span></code>.</p> </dd></dl> <dl class="method"> <dt id="mako.cache.CacheImpl.set"> <code class="sig-name descname">set</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">value</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.CacheImpl.set" title="Permalink to this definition">¶</a></dt> <dd><p>Place a value in the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.cache.CacheImpl.set.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.set.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.cache.CacheImpl.set.params.value"></span><strong>value</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.set.params.value">¶</a> – the value.</p></li> <li><p><span class="target" id="mako.cache.CacheImpl.set.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.cache.CacheImpl.set.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> </dd></dl> <dl class="function"> <dt id="mako.cache.register_plugin"> <code class="sig-prename descclassname">mako.cache.</code><code class="sig-name descname">register_plugin</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">modulepath</em>, <em class="sig-param">objname</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.cache.register_plugin" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <dl class="class"> <dt id="mako.ext.beaker_cache.BeakerCacheImpl"> <em class="property">class </em><code class="sig-prename descclassname">mako.ext.beaker_cache.</code><code class="sig-name descname">BeakerCacheImpl</code><span class="sig-paren">(</span><em class="sig-param">cache</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.ext.beaker_cache.BeakerCacheImpl" title="Permalink to this definition">¶</a></dt> <dd><p>Bases: <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">mako.cache.CacheImpl</span></code></a></p> <p>Bases: <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">mako.cache.CacheImpl</span></code></a></p> <p>A <a class="reference internal" href="#mako.cache.CacheImpl" title="mako.cache.CacheImpl"><code class="xref py py-class docutils literal notranslate"><span class="pre">CacheImpl</span></code></a> provided for the Beaker caching system.</p> <p>This plugin is used by default, based on the default value of <code class="docutils literal notranslate"><span class="pre">'beaker'</span></code> for the <code class="docutils literal notranslate"><span class="pre">cache_impl</span></code> parameter of the <a class="reference internal" href="usage.html#mako.template.Template" title="mako.template.Template"><code class="xref py py-class docutils literal notranslate"><span class="pre">Template</span></code></a> or <a class="reference internal" href="usage.html#mako.lookup.TemplateLookup" title="mako.lookup.TemplateLookup"><code class="xref py py-class docutils literal notranslate"><span class="pre">TemplateLookup</span></code></a> classes.</p> <dl class="method"> <dt id="mako.ext.beaker_cache.BeakerCacheImpl.get"> <code class="sig-name descname">get</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.ext.beaker_cache.BeakerCacheImpl.get" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieve a value from the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.get.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.get.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.get.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.get.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="method"> <dt id="mako.ext.beaker_cache.BeakerCacheImpl.get_or_create"> <code class="sig-name descname">get_or_create</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">creation_function</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.ext.beaker_cache.BeakerCacheImpl.get_or_create" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieve a value from the cache, using the given creation function to generate a new value.</p> <p>This function <em>must</em> return a value, either from the cache, or via the given creation function. If the creation function is called, the newly created value should be populated into the cache under the given key before being returned.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.get_or_create.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.get_or_create.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.get_or_create.params.creation_function"></span><strong>creation_function</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.get_or_create.params.creation_function">¶</a> – function that when called generates a new value.</p></li> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.get_or_create.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.get_or_create.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> <dl class="method"> <dt id="mako.ext.beaker_cache.BeakerCacheImpl.invalidate"> <code class="sig-name descname">invalidate</code><span class="sig-paren">(</span><em class="sig-param">key</em>, <em class="sig-param">**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#mako.ext.beaker_cache.BeakerCacheImpl.invalidate" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate a value in the cache.</p> <dl class="field-list simple"> <dt class="field-odd">Parameters</dt> <dd class="field-odd"><ul class="simple"> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.invalidate.params.key"></span><strong>key</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.invalidate.params.key">¶</a> – the value’s key.</p></li> <li><p><span class="target" id="mako.ext.beaker_cache.BeakerCacheImpl.invalidate.params.**kw"></span><strong>**kw</strong><a class="paramlink headerlink reference internal" href="#mako.ext.beaker_cache.BeakerCacheImpl.invalidate.params.**kw">¶</a> – cache configuration arguments.</p></li> </ul> </dd> </dl> </dd></dl> </dd></dl> </div> </div> </div> </div> <div id="docs-bottom-navigation" class="docs-navigation-links"> Previous: <a href="unicode.html" title="previous chapter">The Unicode Chapter</a> Next: <a href="changelog.html" title="next chapter">Changelog</a> <div id="docs-copyright"> © Copyright the Mako authors and contributors. 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