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<div class="section" id="caching-driver">
<h1>Caching Driver<a class="headerlink" href="#caching-driver" title="Permalink to this headline"></a></h1>
<p>CodeIgniter features wrappers around some of the most popular forms of
fast and dynamic caching. All but file-based caching require specific
server requirements, and a Fatal Exception will be thrown if server
requirements are not met.</p>
<div class="contents local topic" id="contents">
<ul class="simple">
<li><a class="reference internal" href="#example-usage" id="id1">Example Usage</a></li>
<li><a class="reference internal" href="#class-reference" id="id2">Class Reference</a></li>
<li><a class="reference internal" href="#drivers" id="id3">Drivers</a><ul>
<li><a class="reference internal" href="#alternative-php-cache-apc-caching" id="id4">Alternative PHP Cache (APC) Caching</a></li>
<li><a class="reference internal" href="#file-based-caching" id="id5">File-based Caching</a></li>
<li><a class="reference internal" href="#memcached-caching" id="id6">Memcached Caching</a></li>
<li><a class="reference internal" href="#wincache-caching" id="id7">WinCache Caching</a></li>
<li><a class="reference internal" href="#redis-caching" id="id8">Redis Caching</a></li>
<li><a class="reference internal" href="#dummy-cache" id="id9">Dummy Cache</a></li>
</ul>
</li>
</ul>
</div>
<div class="custom-index container"></div><div class="section" id="example-usage">
<h2><a class="toc-backref" href="#id1">Example Usage</a><a class="headerlink" href="#example-usage" title="Permalink to this headline"></a></h2>
<p>The following example will load the cache driver, specify <a class="reference external" href="#alternative-php-cache-apc-caching">APC</a>
as the driver to use, and fall back to file-based caching if APC is not
available in the hosting environment.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">,</span> <span class="k">array</span><span class="p">(</span><span class="s1">&#39;adapter&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;apc&#39;</span><span class="p">,</span> <span class="s1">&#39;backup&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;file&#39;</span><span class="p">));</span>
<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nv">$foo</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">))</span>
<span class="p">{</span>
<span class="k">echo</span> <span class="s1">&#39;Saving to the cache!&lt;br /&gt;&#39;</span><span class="p">;</span>
<span class="nv">$foo</span> <span class="o">=</span> <span class="s1">&#39;foobarbaz!&#39;</span><span class="p">;</span>
<span class="c1">// Save into the cache for 5 minutes</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">,</span> <span class="nv">$foo</span><span class="p">,</span> <span class="mi">300</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">echo</span> <span class="nv">$foo</span><span class="p">;</span>
</pre></div>
</div>
<p>You can also prefix cache item names via the <strong>key_prefix</strong> setting, which is useful
to avoid collisions when youre running multiple applications on the same environment.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">,</span>
<span class="k">array</span><span class="p">(</span><span class="s1">&#39;adapter&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;apc&#39;</span><span class="p">,</span> <span class="s1">&#39;backup&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;file&#39;</span><span class="p">,</span> <span class="s1">&#39;key_prefix&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;my_&#39;</span><span class="p">)</span>
<span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">);</span> <span class="c1">// Will get the cache entry named &#39;my_foo&#39;</span>
</pre></div>
</div>
</div>
<div class="section" id="class-reference">
<h2><a class="toc-backref" href="#id2">Class Reference</a><a class="headerlink" href="#class-reference" title="Permalink to this headline"></a></h2>
<dl class="class">
<dt id="CI_Cache">
<em class="property">class </em><code class="descname">CI_Cache</code><a class="headerlink" href="#CI_Cache" title="Permalink to this definition"></a></dt>
<dd><dl class="method">
<dt id="CI_Cache::is_supported">
<code class="descname">is_supported</code><span class="sig-paren">(</span><em>$driver</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::is_supported" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$driver</strong> (<em>string</em>) the name of the caching driver</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE if supported, FALSE if not</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
</td>
</tr>
</tbody>
</table>
<p>This method is automatically called when accessing drivers via
<code class="docutils literal"><span class="pre">$this-&gt;cache-&gt;get()</span></code>. However, if the individual drivers are used,
make sure to call this method to ensure the driver is supported in the
hosting environment.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">apc</span><span class="o">-&gt;</span><span class="na">is_supported</span><span class="p">())</span>
<span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$data</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">apc</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">(</span><span class="s1">&#39;my_cache&#39;</span><span class="p">))</span>
<span class="p">{</span>
<span class="c1">// do things.</span>
<span class="p">}</span>
<span class="p">}</span>
</pre></div>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::get">
<code class="descname">get</code><span class="sig-paren">(</span><em>$id</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::get" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$id</strong> (<em>string</em>) Cache item name</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Item value or FALSE if not found</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">mixed</p>
</td>
</tr>
</tbody>
</table>
<p>This method will attempt to fetch an item from the cache store. If the
item does not exist, the method will return FALSE.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$foo</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">(</span><span class="s1">&#39;my_cached_item&#39;</span><span class="p">);</span>
</pre></div>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::save">
<code class="descname">save</code><span class="sig-paren">(</span><em>$id</em>, <em>$data</em><span class="optional">[</span>, <em>$ttl = 60</em><span class="optional">[</span>, <em>$raw = FALSE</em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::save" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$id</strong> (<em>string</em>) Cache item name</li>
<li><strong>$data</strong> (<em>mixed</em>) the data to save</li>
<li><strong>$ttl</strong> (<em>int</em>) Time To Live, in seconds (default 60)</li>
<li><strong>$raw</strong> (<em>bool</em>) Whether to store the raw value</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>This method will save an item to the cache store. If saving fails, the
method will return FALSE.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;cache_item_id&#39;</span><span class="p">,</span> <span class="s1">&#39;data_to_cache&#39;</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The <code class="docutils literal"><span class="pre">$raw</span></code> parameter is only utilized by APC and Memcache,
in order to allow usage of <code class="docutils literal"><span class="pre">increment()</span></code> and <code class="docutils literal"><span class="pre">decrement()</span></code>.</p>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::delete">
<code class="descname">delete</code><span class="sig-paren">(</span><em>$id</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::delete" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$id</strong> (<em>string</em>) name of cached item</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
</td>
</tr>
</tbody>
</table>
<p>This method will delete a specific item from the cache store. If item
deletion fails, the method will return FALSE.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">delete</span><span class="p">(</span><span class="s1">&#39;cache_item_id&#39;</span><span class="p">);</span>
</pre></div>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::increment">
<code class="descname">increment</code><span class="sig-paren">(</span><em>$id</em><span class="optional">[</span>, <em>$offset = 1</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::increment" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$id</strong> (<em>string</em>) Cache ID</li>
<li><strong>$offset</strong> (<em>int</em>) Step/value to add</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">New value on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">mixed</p>
</td>
</tr>
</tbody>
</table>
<p>Performs atomic incrementation of a raw stored value.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// &#39;iterator&#39; has a value of 2</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">increment</span><span class="p">(</span><span class="s1">&#39;iterator&#39;</span><span class="p">);</span> <span class="c1">// &#39;iterator&#39; is now 3</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">increment</span><span class="p">(</span><span class="s1">&#39;iterator&#39;</span><span class="p">,</span> <span class="mi">3</span><span class="p">);</span> <span class="c1">// &#39;iterator&#39; is now 6</span>
</pre></div>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::decrement">
<code class="descname">decrement</code><span class="sig-paren">(</span><em>$id</em><span class="optional">[</span>, <em>$offset = 1</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::decrement" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$id</strong> (<em>string</em>) Cache ID</li>
<li><strong>$offset</strong> (<em>int</em>) Step/value to reduce by</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">New value on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">mixed</p>
</td>
</tr>
</tbody>
</table>
<p>Performs atomic decrementation of a raw stored value.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// &#39;iterator&#39; has a value of 6</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">decrement</span><span class="p">(</span><span class="s1">&#39;iterator&#39;</span><span class="p">);</span> <span class="c1">// &#39;iterator&#39; is now 5</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">decrement</span><span class="p">(</span><span class="s1">&#39;iterator&#39;</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span> <span class="c1">// &#39;iterator&#39; is now 3</span>
</pre></div>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::clean">
<code class="descname">clean</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::clean" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">TRUE on success, FALSE on failure</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
</tr>
</tbody>
</table>
<p>This method will clean the entire cache. If the deletion of the
cache files fails, the method will return FALSE.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">clean</span><span class="p">();</span>
</pre></div>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::cache_info">
<code class="descname">cache_info</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::cache_info" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">Information on the entire cache database</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">mixed</td>
</tr>
</tbody>
</table>
<p>This method will return information on the entire cache.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nb">var_dump</span><span class="p">(</span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">cache_info</span><span class="p">());</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The information returned and the structure of the data is dependent
on which adapter is being used.</p>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Cache::get_metadata">
<code class="descname">get_metadata</code><span class="sig-paren">(</span><em>$id</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Cache::get_metadata" title="Permalink to this definition"></a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$id</strong> (<em>string</em>) Cache item name</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Metadata for the cached item</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">mixed</p>
</td>
</tr>
</tbody>
</table>
<p>This method will return detailed information on a specific item in the
cache.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nb">var_dump</span><span class="p">(</span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">get_metadata</span><span class="p">(</span><span class="s1">&#39;my_cached_item&#39;</span><span class="p">));</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The information returned and the structure of the data is dependent
on which adapter is being used.</p>
</div>
</dd></dl>
</dd></dl>
</div>
<div class="section" id="drivers">
<h2><a class="toc-backref" href="#id3">Drivers</a><a class="headerlink" href="#drivers" title="Permalink to this headline"></a></h2>
<div class="section" id="alternative-php-cache-apc-caching">
<h3><a class="toc-backref" href="#id4">Alternative PHP Cache (APC) Caching</a><a class="headerlink" href="#alternative-php-cache-apc-caching" title="Permalink to this headline"></a></h3>
<p>All of the methods listed above can be accessed without passing a
specific adapter to the driver loader as follows:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">apc</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">,</span> <span class="s1">&#39;bar&#39;</span><span class="p">,</span> <span class="mi">10</span><span class="p">);</span>
</pre></div>
</div>
<p>For more information on APC, please see
<a class="reference external" href="http://php.net/apc">http://php.net/apc</a>.</p>
</div>
<div class="section" id="file-based-caching">
<h3><a class="toc-backref" href="#id5">File-based Caching</a><a class="headerlink" href="#file-based-caching" title="Permalink to this headline"></a></h3>
<p>Unlike caching from the Output Class, the driver file-based caching
allows for pieces of view files to be cached. Use this with care, and
make sure to benchmark your application, as a point can come where disk
I/O will negate positive gains by caching.</p>
<p>All of the methods listed above can be accessed without passing a
specific adapter to the driver loader as follows:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">file</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">,</span> <span class="s1">&#39;bar&#39;</span><span class="p">,</span> <span class="mi">10</span><span class="p">);</span>
</pre></div>
</div>
</div>
<div class="section" id="memcached-caching">
<h3><a class="toc-backref" href="#id6">Memcached Caching</a><a class="headerlink" href="#memcached-caching" title="Permalink to this headline"></a></h3>
<p>Multiple Memcached servers can be specified in the memcached.php
configuration file, located in the _application/config/* directory.</p>
<p>All of the methods listed above can be accessed without passing a
specific adapter to the driver loader as follows:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">memcached</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">,</span> <span class="s1">&#39;bar&#39;</span><span class="p">,</span> <span class="mi">10</span><span class="p">);</span>
</pre></div>
</div>
<p>For more information on Memcached, please see
<a class="reference external" href="http://php.net/memcached">http://php.net/memcached</a>.</p>
</div>
<div class="section" id="wincache-caching">
<h3><a class="toc-backref" href="#id7">WinCache Caching</a><a class="headerlink" href="#wincache-caching" title="Permalink to this headline"></a></h3>
<p>Under Windows, you can also utilize the WinCache driver.</p>
<p>All of the methods listed above can be accessed without passing a
specific adapter to the driver loader as follows:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">wincache</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">,</span> <span class="s1">&#39;bar&#39;</span><span class="p">,</span> <span class="mi">10</span><span class="p">);</span>
</pre></div>
</div>
<p>For more information on WinCache, please see
<a class="reference external" href="http://php.net/wincache">http://php.net/wincache</a>.</p>
</div>
<div class="section" id="redis-caching">
<h3><a class="toc-backref" href="#id8">Redis Caching</a><a class="headerlink" href="#redis-caching" title="Permalink to this headline"></a></h3>
<p>Redis is an in-memory key-value store which can operate in LRU cache mode.
To use it, you need <a class="reference external" href="https://github.com/phpredis/phpredis">Redis server and phpredis PHP extension</a>.</p>
<p>Config options to connect to redis server must be stored in the application/config/redis.php file.
Available options are:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;socket_type&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;tcp&#39;</span><span class="p">;</span> <span class="c1">//`tcp` or `unix`</span>
<span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;socket&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;/var/run/redis.sock&#39;</span><span class="p">;</span> <span class="c1">// in case of `unix` socket type</span>
<span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;host&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;127.0.0.1&#39;</span><span class="p">;</span>
<span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;password&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="k">NULL</span><span class="p">;</span>
<span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;port&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="mi">6379</span><span class="p">;</span>
<span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;timeout&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
</pre></div>
</div>
<p>All of the methods listed above can be accessed without passing a
specific adapter to the driver loader as follows:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">driver</span><span class="p">(</span><span class="s1">&#39;cache&#39;</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">cache</span><span class="o">-&gt;</span><span class="na">redis</span><span class="o">-&gt;</span><span class="na">save</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">,</span> <span class="s1">&#39;bar&#39;</span><span class="p">,</span> <span class="mi">10</span><span class="p">);</span>
</pre></div>
</div>
<p>For more information on Redis, please see
<a class="reference external" href="http://redis.io">http://redis.io</a>.</p>
</div>
<div class="section" id="dummy-cache">
<h3><a class="toc-backref" href="#id9">Dummy Cache</a><a class="headerlink" href="#dummy-cache" title="Permalink to this headline"></a></h3>
<p>This is a caching backend that will always miss. It stores no data,
but lets you keep your caching code in place in environments that dont
support your chosen cache.</p>
</div>
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