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<h1>Source code for webnotes.utils.cache</h1><div class="highlight"><pre>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd">Simple Caching:</span>
<span class="sd">Stores key-value pairs in database and enables simple caching</span>
<span class="sd">get_item(key).get() returns the cached value if not expired (else returns null)</span>
<span class="sd">get_item(key).set(interval = 60000) sets a value to cache, expiring after x seconds</span>
<span class="sd">get_item(key).clear() clears an old value</span>
<span class="sd">setup() sets up cache</span>
<span class="sd">&quot;&quot;&quot;</span>
<span class="kn">import</span> <span class="nn">webnotes</span>
<div class="viewcode-block" id="CacheItem"><a class="viewcode-back" href="../../../webnotes.utils.html#webnotes.utils.cache.CacheItem">[docs]</a><span class="k">class</span> <span class="nc">CacheItem</span><span class="p">:</span>
<span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;create a new cache&quot;&quot;&quot;</span>
<span class="bp">self</span><span class="o">.</span><span class="n">key</span> <span class="o">=</span> <span class="n">key</span>
<div class="viewcode-block" id="CacheItem.get"><a class="viewcode-back" href="../../../webnotes.utils.html#webnotes.utils.cache.CacheItem.get">[docs]</a> <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="sd">&quot;&quot;&quot;get value&quot;&quot;&quot;</span>
<span class="k">try</span><span class="p">:</span>
<span class="k">return</span> <span class="n">webnotes</span><span class="o">.</span><span class="n">conn</span><span class="o">.</span><span class="n">sql</span><span class="p">(</span><span class="s">&quot;select `value` from __CacheItem where `key`=</span><span class="si">%s</span><span class="s"> and expires_on &gt; NOW()&quot;</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">key</span><span class="p">)[</span><span class="mi">0</span><span class="p">][</span><span class="mi">0</span><span class="p">]</span>
<span class="k">except</span> <span class="ne">Exception</span><span class="p">:</span>
<span class="k">return</span> <span class="bp">None</span>
</div>
<div class="viewcode-block" id="CacheItem.set"><a class="viewcode-back" href="../../../webnotes.utils.html#webnotes.utils.cache.CacheItem.set">[docs]</a> <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">value</span><span class="p">,</span> <span class="n">interval</span><span class="o">=</span><span class="mi">6000</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;set a new value, with interval&quot;&quot;&quot;</span>
<span class="k">try</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">clear</span><span class="p">()</span>
<span class="n">webnotes</span><span class="o">.</span><span class="n">conn</span><span class="o">.</span><span class="n">sql</span><span class="p">(</span><span class="s">&quot;&quot;&quot;INSERT INTO </span>
<span class="s"> __CacheItem (`key`, `value`, expires_on) </span>
<span class="s"> VALUES </span>
<span class="s"> (</span><span class="si">%s</span><span class="s">, </span><span class="si">%s</span><span class="s">, addtime(now(), sec_to_time(</span><span class="si">%s</span><span class="s">)))</span>
<span class="s"> &quot;&quot;&quot;</span><span class="p">,</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">key</span><span class="p">,</span> <span class="nb">str</span><span class="p">(</span><span class="n">value</span><span class="p">),</span> <span class="n">interval</span><span class="p">))</span>
<span class="k">except</span> <span class="ne">Exception</span><span class="p">,</span> <span class="n">e</span><span class="p">:</span>
<span class="k">if</span> <span class="n">e</span><span class="o">.</span><span class="n">args</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">==</span><span class="mi">1146</span><span class="p">:</span>
<span class="n">setup</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">interval</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span> <span class="k">raise</span> <span class="n">e</span>
</div>
<div class="viewcode-block" id="CacheItem.clear"><a class="viewcode-back" href="../../../webnotes.utils.html#webnotes.utils.cache.CacheItem.clear">[docs]</a> <span class="k">def</span> <span class="nf">clear</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;clear the item&quot;&quot;&quot;</span>
<span class="n">webnotes</span><span class="o">.</span><span class="n">conn</span><span class="o">.</span><span class="n">sql</span><span class="p">(</span><span class="s">&quot;delete from __CacheItem where `key`=</span><span class="si">%s</span><span class="s">&quot;</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">key</span><span class="p">)</span>
</div></div>
<div class="viewcode-block" id="setup"><a class="viewcode-back" href="../../../webnotes.utils.html#webnotes.utils.cache.setup">[docs]</a><span class="k">def</span> <span class="nf">setup</span><span class="p">():</span>
<span class="n">webnotes</span><span class="o">.</span><span class="n">conn</span><span class="o">.</span><span class="n">commit</span><span class="p">()</span>
<span class="n">webnotes</span><span class="o">.</span><span class="n">conn</span><span class="o">.</span><span class="n">sql</span><span class="p">(</span><span class="s">&quot;&quot;&quot;create table __CacheItem(</span>
<span class="s"> `key` VARCHAR(180) NOT NULL PRIMARY KEY,</span>
<span class="s"> `value` TEXT,</span>
<span class="s"> `expires_on` TIMESTAMP</span>
<span class="s"> )&quot;&quot;&quot;</span><span class="p">)</span>
<span class="n">webnotes</span><span class="o">.</span><span class="n">conn</span><span class="o">.</span><span class="n">begin</span><span class="p">()</span>
</div>
<div class="viewcode-block" id="get_item"><a class="viewcode-back" href="../../../webnotes.utils.html#webnotes.utils.cache.get_item">[docs]</a><span class="k">def</span> <span class="nf">get_item</span><span class="p">(</span><span class="n">key</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;returns get CacheItem object&quot;&quot;&quot;</span>
<span class="k">return</span> <span class="n">CacheItem</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<span class="k">pass</span></div>
</pre></div>
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