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 173   <div class="section" id="libmemcached-examples">
 174 <h1>libmemcached Examples<a class="headerlink" href="#libmemcached-examples" title="Permalink to this headline">¶</a></h1>
 175 <p>Examples for libmemcached</p>
 176 <div class="section" id="description">
 177 <h2>DESCRIPTION<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
 178 <p>For full examples, test cases are found in tests/*.c in the main distribution.
 179 These are always up to date, and are used for each test run of the library.</p>
 180 </div>
 181 <div class="section" id="connecting-to-servers">
 182 <h2>Connecting to servers<a class="headerlink" href="#connecting-to-servers" title="Permalink to this headline">¶</a></h2>
 183 <div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="n">config_string</span> <span class="o">=</span>
 184   <span class="s">&quot;--SERVER=host10.example.com &quot;</span>
 185   <span class="s">&quot;--SERVER=host11.example.com &quot;</span>
 186   <span class="s">&quot;--SERVER=host10.example.com&quot;</span><span class="p">;</span>
 187 <span class="n">memcached_st</span> <span class="o">*</span><span class="n">memc</span><span class="o">=</span> <span class="n">memcached</span><span class="p">(</span><span class="n">config_string</span><span class="p">,</span> <span class="n">strlen</span><span class="p">(</span><span class="n">config_string</span><span class="p">);</span>
 188 <span class="p">{</span>
 189   <span class="c1">// ...</span>
 190 <span class="p">}</span>
 191  <span class="n">memcached_free</span><span class="p">(</span><span class="n">memc</span><span class="p">);</span>
 192 </pre></div>
 193 </div>
 194 <p>In the above code you create a <a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_st</span></code></a> object with three server by making
 195 use of <a class="reference internal" href="memcached_create.html#_CPPv416memcached_createP12memcached_st" title="memcached_create"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_create()</span></code></a>.</p>
 196 </div>
 197 <div class="section" id="creating-a-pool-of-servers">
 198 <h2>Creating a pool of servers<a class="headerlink" href="#creating-a-pool-of-servers" title="Permalink to this headline">¶</a></h2>
 199 <div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="n">config_string</span> <span class="o">=</span>
 200   <span class="s">&quot;--SERVER=host10.example.com &quot;</span>
 201   <span class="s">&quot;--SERVER=host11.example.com &quot;</span>
 202   <span class="s">&quot;--SERVER=host10.example.com&quot;</span><span class="p">;</span>
 203
 204 <span class="n">memcached_pool_st</span><span class="o">*</span> <span class="n">pool</span><span class="o">=</span> <span class="n">memcached_pool</span><span class="p">(</span><span class="n">config_string</span><span class="p">,</span> <span class="n">strlen</span><span class="p">(</span><span class="n">config_string</span><span class="p">));</span>
 205
 206 <span class="n">memcached_return_t</span> <span class="n">rc</span><span class="p">;</span>
 207
 208 <span class="n">memcached_st</span> <span class="o">*</span><span class="n">memc</span><span class="o">=</span> <span class="n">memcached_pool_pop</span><span class="p">(</span><span class="n">pool</span><span class="p">,</span> <span class="nb">false</span><span class="p">,</span> <span class="o">&amp;</span><span class="n">rc</span><span class="p">);</span>
 209
 210 <span class="c1">// .... do work</span>
 211
 212 <span class="cm">/*</span>
 213 <span class="cm">  Release the memc_ptr that was pulled from the pool</span>
 214 <span class="cm">*/</span>
 215 <span class="n">memcached_pool_push</span><span class="p">(</span><span class="n">pool</span><span class="p">,</span> <span class="n">memc</span><span class="p">);</span>
 216
 217 <span class="cm">/*</span>
 218 <span class="cm">  Destroy the pool.</span>
 219 <span class="cm">*/</span>
 220 <span class="n">memcached_pool_destroy</span><span class="p">(</span><span class="n">pool</span><span class="p">);</span>
 221 </pre></div>
 222 </div>
 223 <p>In the above code you create a <a class="reference internal" href="../libmemcachedutil/memcached_pool.html#_CPPv417memcached_pool_st" title="memcached_pool_st"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_pool_st</span></code></a> object with three server by
 224 making use of <a class="reference internal" href="../libmemcachedutil/memcached_pool.html#_CPPv414memcached_poolPKc6size_t" title="memcached_pool"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_pool()</span></code></a>.</p>
 225 <p>When <a class="reference internal" href="../libmemcachedutil/memcached_pool.html#_CPPv422memcached_pool_destroyP17memcached_pool_st" title="memcached_pool_destroy"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_pool_destroy()</span></code></a> all memory will be released that is associated
 226 with the pool.</p>
 227 </div>
 228 <div class="section" id="adding-a-value-to-the-server">
 229 <h2>Adding a value to the server<a class="headerlink" href="#adding-a-value-to-the-server" title="Permalink to this headline">¶</a></h2>
 230 <div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="kt">char</span> <span class="o">*</span><span class="n">key</span><span class="o">=</span> <span class="s">&quot;foo&quot;</span><span class="p">;</span>
 231 <span class="kt">char</span> <span class="o">*</span><span class="n">value</span><span class="o">=</span> <span class="s">&quot;value&quot;</span><span class="p">;</span>
 232 <span class="kt">time_t</span> <span class="n">expires</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 233 <span class="kt">uint32_t</span> <span class="n">flags</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 234
 235 <span class="n">memcached_return_t</span> <span class="n">rc</span> <span class="o">=</span> <span class="n">memcached_set</span><span class="p">(</span><span class="n">memc</span><span class="p">,</span>
 236                                      <span class="n">key</span><span class="p">,</span> <span class="n">strlen</span><span class="p">(</span><span class="n">key</span><span class="p">),</span>
 237                                      <span class="n">value</span><span class="p">,</span> <span class="n">value_length</span><span class="p">,</span>
 238                                      <span class="n">expires</span><span class="p">,</span> <span class="n">flags</span><span class="p">);</span>
 239
 240 <span class="k">if</span> <span class="p">(</span><span class="n">rc</span> <span class="o">!=</span> <span class="n">MEMCACHED_SUCCESS</span><span class="p">)</span>
 241 <span class="p">{</span>
 242     <span class="c1">// handle failure</span>
 243 <span class="p">}</span>
 244 </pre></div>
 245 </div>
 246 <p>It is best practice to always look at the return value of any operation.</p>
 247 </div>
 248 <div class="section" id="fetching-multiple-values">
 249 <h2>Fetching multiple values<a class="headerlink" href="#fetching-multiple-values" title="Permalink to this headline">¶</a></h2>
 250 <div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="n">memcached_return_t</span> <span class="n">rc</span><span class="p">;</span>
 251 <span class="kt">char</span> <span class="o">*</span><span class="n">keys</span><span class="p">[]</span><span class="o">=</span> <span class="p">{</span><span class="s">&quot;fudge&quot;</span><span class="p">,</span> <span class="s">&quot;son&quot;</span><span class="p">,</span> <span class="s">&quot;food&quot;</span><span class="p">};</span>
 252 <span class="kt">size_t</span> <span class="n">key_length</span><span class="p">[]</span><span class="o">=</span> <span class="p">{</span><span class="mi">5</span><span class="p">,</span> <span class="mi">3</span><span class="p">,</span> <span class="mi">4</span><span class="p">};</span>
 253 <span class="kt">unsigned</span> <span class="kt">int</span> <span class="n">x</span><span class="p">;</span>
 254 <span class="kt">uint32_t</span> <span class="n">flags</span><span class="p">;</span>
 255
 256 <span class="kt">char</span> <span class="n">return_key</span><span class="p">[</span><span class="n">MEMCACHED_MAX_KEY</span><span class="p">];</span>
 257 <span class="kt">size_t</span> <span class="n">return_key_length</span><span class="p">;</span>
 258 <span class="kt">char</span> <span class="o">*</span><span class="n">return_value</span><span class="p">;</span>
 259 <span class="kt">size_t</span> <span class="n">return_value_length</span><span class="p">;</span>
 260
 261 <span class="n">rc</span><span class="o">=</span> <span class="n">memcached_mget</span><span class="p">(</span><span class="n">memc</span><span class="p">,</span> <span class="n">keys</span><span class="p">,</span> <span class="n">key_length</span><span class="p">,</span> <span class="mi">3</span><span class="p">);</span>
 262
 263 <span class="n">x</span><span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 264 <span class="k">while</span> <span class="p">((</span><span class="n">return_value</span><span class="o">=</span> <span class="n">memcached_fetch</span><span class="p">(</span><span class="n">memc</span><span class="p">,</span> <span class="n">return_key</span><span class="p">,</span> <span class="o">&amp;</span><span class="n">return_key_length</span><span class="p">,</span>
 265                                  <span class="o">&amp;</span><span class="n">return_value_length</span><span class="p">,</span> <span class="o">&amp;</span><span class="n">flags</span><span class="p">,</span> <span class="o">&amp;</span><span class="n">rc</span><span class="p">)))</span>
 266 <span class="p">{</span>
 267     <span class="n">free</span><span class="p">(</span><span class="n">return_value</span><span class="p">);</span>
 268     <span class="n">x</span><span class="o">++</span><span class="p">;</span>
 269 <span class="p">}</span>
 270 </pre></div>
 271 </div>
 272 <p>Notice that you freed values returned from memcached_fetch(). The define
 273 <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_MAX_KEY</span></code> is provided for usage.</p>
 274 </div>
 275 <div class="section" id="see-also">
 276 <h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
 277 <blockquote>
 278 <div><em class="manpage"><a class="manpage reference external" href="https://linux.die.net/man/1/memcached">memcached(1)</a></em></div></blockquote>
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