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 184   <div class="section" id="libmemcached-examples">
 185 <h1>libmemcached Examples<a class="headerlink" href="#libmemcached-examples" title="Permalink to this headline">¶</a></h1>
 186 <p>Examples for libmemcached</p>
 187 <div class="section" id="description">
 188 <h2>DESCRIPTION<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
 189 <p>For full examples, test cases are found in tests/*.c in the main distribution.
 190 These are always up to date, and are used for each test run of the library.</p>
 191 </div>
 192 <div class="section" id="connecting-to-servers">
 193 <h2>Connecting to servers<a class="headerlink" href="#connecting-to-servers" title="Permalink to this headline">¶</a></h2>
 194 <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>
 195   <span class="s">&quot;--SERVER=host10.example.com &quot;</span>
 196   <span class="s">&quot;--SERVER=host11.example.com &quot;</span>
 197   <span class="s">&quot;--SERVER=host10.example.com&quot;</span><span class="p">;</span>
 198 <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>
 199 <span class="p">{</span>
 200   <span class="c1">// ...</span>
 201 <span class="p">}</span>
 202  <span class="n">memcached_free</span><span class="p">(</span><span class="n">memc</span><span class="p">);</span>
 203 </pre></div>
 204 </div>
 205 <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
 206 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>
 207 </div>
 208 <div class="section" id="creating-a-pool-of-servers">
 209 <h2>Creating a pool of servers<a class="headerlink" href="#creating-a-pool-of-servers" title="Permalink to this headline">¶</a></h2>
 210 <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>
 211   <span class="s">&quot;--SERVER=host10.example.com &quot;</span>
 212   <span class="s">&quot;--SERVER=host11.example.com &quot;</span>
 213   <span class="s">&quot;--SERVER=host10.example.com&quot;</span><span class="p">;</span>
 214
 215 <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>
 216
 217 <span class="n">memcached_return_t</span> <span class="n">rc</span><span class="p">;</span>
 218
 219 <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>
 220
 221 <span class="c1">// .... do work</span>
 222
 223 <span class="cm">/*</span>
 224 <span class="cm">  Release the memc_ptr that was pulled from the pool</span>
 225 <span class="cm">*/</span>
 226 <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>
 227
 228 <span class="cm">/*</span>
 229 <span class="cm">  Destroy the pool.</span>
 230 <span class="cm">*/</span>
 231 <span class="n">memcached_pool_destroy</span><span class="p">(</span><span class="n">pool</span><span class="p">);</span>
 232 </pre></div>
 233 </div>
 234 <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
 235 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>
 236 <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
 237 with the pool.</p>
 238 </div>
 239 <div class="section" id="adding-a-value-to-the-server">
 240 <h2>Adding a value to the server<a class="headerlink" href="#adding-a-value-to-the-server" title="Permalink to this headline">¶</a></h2>
 241 <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>
 242 <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>
 243 <span class="kt">time_t</span> <span class="n">expires</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 244 <span class="kt">uint32_t</span> <span class="n">flags</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 245
 246 <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>
 247                                      <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>
 248                                      <span class="n">value</span><span class="p">,</span> <span class="n">value_length</span><span class="p">,</span>
 249                                      <span class="n">expires</span><span class="p">,</span> <span class="n">flags</span><span class="p">);</span>
 250
 251 <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>
 252 <span class="p">{</span>
 253     <span class="c1">// handle failure</span>
 254 <span class="p">}</span>
 255 </pre></div>
 256 </div>
 257 <p>It is best practice to always look at the return value of any operation.</p>
 258 </div>
 259 <div class="section" id="fetching-multiple-values">
 260 <h2>Fetching multiple values<a class="headerlink" href="#fetching-multiple-values" title="Permalink to this headline">¶</a></h2>
 261 <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>
 262 <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>
 263 <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>
 264 <span class="kt">unsigned</span> <span class="kt">int</span> <span class="n">x</span><span class="p">;</span>
 265 <span class="kt">uint32_t</span> <span class="n">flags</span><span class="p">;</span>
 266
 267 <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>
 268 <span class="kt">size_t</span> <span class="n">return_key_length</span><span class="p">;</span>
 269 <span class="kt">char</span> <span class="o">*</span><span class="n">return_value</span><span class="p">;</span>
 270 <span class="kt">size_t</span> <span class="n">return_value_length</span><span class="p">;</span>
 271
 272 <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>
 273
 274 <span class="n">x</span><span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 275 <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>
 276                                  <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>
 277 <span class="p">{</span>
 278     <span class="n">free</span><span class="p">(</span><span class="n">return_value</span><span class="p">);</span>
 279     <span class="n">x</span><span class="o">++</span><span class="p">;</span>
 280 <span class="p">}</span>
 281 </pre></div>
 282 </div>
 283 <p>Notice that you freed values returned from memcached_fetch(). The define
 284 <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_MAX_KEY</span></code> is provided for usage.</p>
 285 </div>
 286 <div class="section" id="see-also">
 287 <h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
 288 <blockquote>
 289 <div><p><em class="manpage"><a class="manpage reference external" href="https://linux.die.net/man/1/memcached">memcached(1)</a></em></p>
 290 </div></blockquote>
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