git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/examples.html

   1
   2
   3 <!DOCTYPE html>
   4 <!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
   5 <!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
   6 <head>
   7   <meta charset="utf-8">
   8
   9   <meta name="viewport" content="width=device-width, initial-scale=1.0">
  10
  11   <title>libmemcached Examples &mdash; libmemcached 1.0.99 documentation</title>
  12
  13
  14
  15
  16
  17
  18
  19
  20   <script type="text/javascript" src="../_static/js/modernizr.min.js"></script>
  21
  22
  23       <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script>
  24         <script src="../_static/jquery.js"></script>
  25         <script src="../_static/underscore.js"></script>
  26         <script src="../_static/doctools.js"></script>
  27         <script src="../_static/language_data.js"></script>
  28
  29     <script type="text/javascript" src="../_static/js/theme.js"></script>
  30
  31
  32
  33
  34   <link rel="stylesheet" href="../_static/css/theme.css" type="text/css" />
  35   <link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
  36     <link rel="index" title="Index" href="../genindex.html" />
  37     <link rel="search" title="Search" href="../search.html" />
  38     <link rel="copyright" title="Copyright" href="../copyright.html" />
  39     <link rel="next" title="libmemcached Versioning" href="versioning.html" />
  40     <link rel="prev" title="libmemcached Constants and Defaults" href="constants.html" />
  41 </head>
  42
  43 <body class="wy-body-for-nav">
  44
  45
  46   <div class="wy-grid-for-nav">
  47
  48     <nav data-toggle="wy-nav-shift" class="wy-nav-side">
  49       <div class="wy-side-scroll">
  50         <div class="wy-side-nav-search" >
  51
  52
  53
  54             <a href="../index.html" class="icon icon-home"> libmemcached
  55
  56
  57
  58           </a>
  59
  60
  61
  62
  63               <div class="version">
  64                 1.0
  65               </div>
  66
  67
  68
  69
  70 <div role="search">
  71   <form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
  72     <input type="text" name="q" placeholder="Search docs" />
  73     <input type="hidden" name="check_keywords" value="yes" />
  74     <input type="hidden" name="area" value="default" />
  75   </form>
  76 </div>
  77
  78
  79         </div>
  80
  81         <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
  82
  83
  84
  85
  86
  87
  88               <p class="caption"><span class="caption-text">libmemcached</span></p>
  89 <ul class="current">
  90 <li class="toctree-l1"><a class="reference internal" href="../libmemcached.html">Introduction</a></li>
  91 <li class="toctree-l1"><a class="reference internal" href="index.html">libmemcached API</a><ul>
  92 <li class="toctree-l2"><a class="reference internal" href="index_basics.html">Basics</a></li>
  93 <li class="toctree-l2"><a class="reference internal" href="index_data.html">Working with Data</a></li>
  94 <li class="toctree-l2"><a class="reference internal" href="index_errors.html">Messages and Errors</a></li>
  95 <li class="toctree-l2"><a class="reference internal" href="index_advanced.html">Advanced Topics</a></li>
  96 <li class="toctree-l2"><a class="reference internal" href="index_deprecated.html">Deprecated Functionality</a></li>
  97 </ul>
  98 </li>
  99 <li class="toctree-l1 current"><a class="reference internal" href="index_misc.html">Misc</a><ul class="current">
 100 <li class="toctree-l2"><a class="reference internal" href="configuration.html">Configuration</a></li>
 101 <li class="toctree-l2"><a class="reference internal" href="constants.html">Constants</a></li>
 102 <li class="toctree-l2 current"><a class="current reference internal" href="#">Examples</a></li>
 103 <li class="toctree-l2"><a class="reference internal" href="versioning.html">Versioning</a></li>
 104 </ul>
 105 </li>
 106 </ul>
 107 <p class="caption"><span class="caption-text">libmemcachedutil</span></p>
 108 <ul>
 109 <li class="toctree-l1"><a class="reference internal" href="../libmemcachedutil.html">Introduction</a></li>
 110 <li class="toctree-l1"><a class="reference internal" href="../libmemcachedutil/index.html">libmemcachedutil API</a><ul>
 111 <li class="toctree-l2"><a class="reference internal" href="../libmemcachedutil/memcached_pool.html">Working with memcached pools</a></li>
 112 </ul>
 113 </li>
 114 </ul>
 115 <p class="caption"><span class="caption-text">libhashkit</span></p>
 116 <ul>
 117 <li class="toctree-l1"><a class="reference internal" href="../libhashkit.html">Introduction</a></li>
 118 <li class="toctree-l1"><a class="reference internal" href="../libhashkit/index.html">libhashkit API</a><ul>
 119 <li class="toctree-l2"><a class="reference internal" href="../libhashkit/hashkit_create.html">Creating a hashkit structure</a></li>
 120 <li class="toctree-l2"><a class="reference internal" href="../libhashkit/hashkit_function.html">Set Hash Function</a></li>
 121 <li class="toctree-l2"><a class="reference internal" href="../libhashkit/hashkit_functions.html">Available Hashes</a></li>
 122 <li class="toctree-l2"><a class="reference internal" href="../libhashkit/hashkit_value.html">Generate hash value</a></li>
 123 </ul>
 124 </li>
 125 </ul>
 126 <p class="caption"><span class="caption-text">Client Applications</span></p>
 127 <ul>
 128 <li class="toctree-l1"><a class="reference internal" href="../bin/index.html">Client Applications</a><ul>
 129 <li class="toctree-l2"><a class="reference internal" href="../bin/memcapable.html">memcapable - Checking a Memcached server capabilities and compatibility</a></li>
 130 <li class="toctree-l2"><a class="reference internal" href="../bin/memcat.html">memcat - “cat” data from a server</a></li>
 131 <li class="toctree-l2"><a class="reference internal" href="../bin/memcp.html">memcp - Copy data to a server</a></li>
 132 <li class="toctree-l2"><a class="reference internal" href="../bin/memdump.html">memdump - Dumping your server</a></li>
 133 <li class="toctree-l2"><a class="reference internal" href="../bin/memerror.html">memerror - translate an error code to a string</a></li>
 134 <li class="toctree-l2"><a class="reference internal" href="../bin/memflush.html">memflush - flush all data from a server</a></li>
 135 <li class="toctree-l2"><a class="reference internal" href="../bin/memrm.html">memrm - Remove data from a server</a></li>
 136 <li class="toctree-l2"><a class="reference internal" href="../bin/memslap.html">memslap - Load testing  and benchmarking a server</a></li>
 137 <li class="toctree-l2"><a class="reference internal" href="../bin/memaslap.html">memaslap - Load testing  and benchmarking a server</a></li>
 138 <li class="toctree-l2"><a class="reference internal" href="../bin/memstat.html">memstat - Gather statistics from a server</a></li>
 139 <li class="toctree-l2"><a class="reference internal" href="../bin/memexist.html">memexist - Check for the existence of a key</a></li>
 140 <li class="toctree-l2"><a class="reference internal" href="../bin/memparse.html">memparse - Parse an option string</a></li>
 141 <li class="toctree-l2"><a class="reference internal" href="../bin/memping.html">memping - Test to see if a server is available.</a></li>
 142 <li class="toctree-l2"><a class="reference internal" href="../bin/memtouch.html">memtouch - Touches a key.</a></li>
 143 </ul>
 144 </li>
 145 </ul>
 146
 147
 148
 149         </div>
 150       </div>
 151     </nav>
 152
 153     <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
 154
 155
 156       <nav class="wy-nav-top" aria-label="top navigation">
 157
 158           <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
 159           <a href="../index.html">libmemcached</a>
 160
 161       </nav>
 162
 163
 164       <div class="wy-nav-content">
 165
 166         <div class="rst-content">
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184 <div role="navigation" aria-label="breadcrumbs navigation">
 185
 186   <ul class="wy-breadcrumbs">
 187
 188       <li><a href="../index.html">Docs</a> &raquo;</li>
 189
 190           <li><a href="index_misc.html">Misc</a> &raquo;</li>
 191
 192       <li>libmemcached Examples</li>
 193
 194
 195       <li class="wy-breadcrumbs-aside">
 196
 197
 198
 199       </li>
 200
 201   </ul>
 202
 203
 204   <hr/>
 205 </div>
 206           <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
 207            <div itemprop="articleBody">
 208
 209   <div class="section" id="libmemcached-examples">
 210 <h1>libmemcached Examples<a class="headerlink" href="#libmemcached-examples" title="Permalink to this headline">¶</a></h1>
 211 <p>Examples for libmemcached</p>
 212 <div class="section" id="description">
 213 <h2>DESCRIPTION<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
 214 <p>For full examples, test cases are found in tests/*.c in the main
 215 distribution. These are always up to date, and are used for each test run of
 216 the library.</p>
 217 </div>
 218 <div class="section" id="connecting-to-servers">
 219 <h2>Connecting to servers<a class="headerlink" href="#connecting-to-servers" title="Permalink to this headline">¶</a></h2>
 220 <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>
 221   <span class="s">&quot;--SERVER=host10.example.com &quot;</span>
 222   <span class="s">&quot;--SERVER=host11.example.com &quot;</span>
 223   <span class="s">&quot;--SERVER=host10.example.com&quot;</span><span class="p">;</span>
 224 <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>
 225 <span class="p">{</span>
 226   <span class="c1">// ...</span>
 227 <span class="p">}</span>
 228  <span class="n">memcached_free</span><span class="p">(</span><span class="n">memc</span><span class="p">);</span>
 229 </pre></div>
 230 </div>
 231 <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-type docutils literal notranslate"><span class="pre">memcached_st</span></code></a> object with three server
 232 by making use of <a class="reference internal" href="memcached_create.html#_CPPv416memcached_createP12memcached_st" title="memcached_create"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_create()</span></code></a>.</p>
 233 </div>
 234 <div class="section" id="creating-a-pool-of-servers">
 235 <h2>Creating a pool of servers<a class="headerlink" href="#creating-a-pool-of-servers" title="Permalink to this headline">¶</a></h2>
 236 <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> <span class="s">&quot;--SERVER=host10.example.com --SERVER=host11.example.com --SERVER=host10.example.com&quot;</span><span class="p">;</span>
 237
 238 <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>
 239
 240 <span class="n">memcached_return_t</span> <span class="n">rc</span><span class="p">;</span>
 241
 242 <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>
 243
 244 <span class="c1">// .... do work</span>
 245
 246 <span class="cm">/*</span>
 247 <span class="cm">  Release the memc_ptr that was pulled from the pool</span>
 248 <span class="cm">*/</span>
 249 <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>
 250
 251 <span class="cm">/*</span>
 252 <span class="cm">  Destroy the pool.</span>
 253 <span class="cm">*/</span>
 254 <span class="n">memcached_pool_destroy</span><span class="p">(</span><span class="n">pool</span><span class="p">);</span>
 255 </pre></div>
 256 </div>
 257 <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-type docutils literal notranslate"><span class="pre">memcached_pool_st</span></code></a> object with three
 258 server by making use of <a class="reference internal" href="../libmemcachedutil/memcached_pool.html#_CPPv414memcached_poolPKc6size_t" title="memcached_pool"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_pool()</span></code></a>.</p>
 259 <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-func docutils literal notranslate"><span class="pre">memcached_pool_destroy()</span></code></a> all memory will be released that is associated
 260 with the pool.</p>
 261 </div>
 262 <div class="section" id="adding-a-value-to-the-server">
 263 <h2>Adding a value to the server<a class="headerlink" href="#adding-a-value-to-the-server" title="Permalink to this headline">¶</a></h2>
 264 <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>
 265 <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>
 266 <span class="kt">time_t</span> <span class="n">expires</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 267 <span class="kt">uint32_t</span> <span class="n">flags</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 268
 269 <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>
 270                                      <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>
 271                                      <span class="n">value</span><span class="p">,</span> <span class="n">value_length</span><span class="p">,</span>
 272                                      <span class="n">expires</span><span class="p">,</span> <span class="n">flags</span><span class="p">);</span>
 273
 274 <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>
 275 <span class="p">{</span>
 276     <span class="c1">// handle failure</span>
 277 <span class="p">}</span>
 278 </pre></div>
 279 </div>
 280 <p>It is best practice to always look at the return value of any operation.</p>
 281 </div>
 282 <div class="section" id="fetching-multiple-values">
 283 <h2>Fetching multiple values<a class="headerlink" href="#fetching-multiple-values" title="Permalink to this headline">¶</a></h2>
 284 <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>
 285 <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>
 286 <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>
 287 <span class="kt">unsigned</span> <span class="kt">int</span> <span class="n">x</span><span class="p">;</span>
 288 <span class="kt">uint32_t</span> <span class="n">flags</span><span class="p">;</span>
 289
 290 <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>
 291 <span class="kt">size_t</span> <span class="n">return_key_length</span><span class="p">;</span>
 292 <span class="kt">char</span> <span class="o">*</span><span class="n">return_value</span><span class="p">;</span>
 293 <span class="kt">size_t</span> <span class="n">return_value_length</span><span class="p">;</span>
 294
 295 <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>
 296
 297 <span class="n">x</span><span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
 298 <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>
 299                                  <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>
 300 <span class="p">{</span>
 301     <span class="n">free</span><span class="p">(</span><span class="n">return_value</span><span class="p">);</span>
 302     <span class="n">x</span><span class="o">++</span><span class="p">;</span>
 303 <span class="p">}</span>
 304 </pre></div>
 305 </div>
 306 <p>Notice that you freed values returned from memcached_fetch(). The define
 307 <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_MAX_KEY</span></code> is provided for usage.</p>
 308 </div>
 309 <div class="section" id="see-also">
 310 <h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
 311 <blockquote>
 312 <div><p><em class="manpage"><a class="manpage reference external" href="http://man7.org/linux/man-pages/man1/memcached.1.html">memcached(1)</a></em></p>
 313 </div></blockquote>
 314 </div>
 315 </div>
 316
 317
 318            </div>
 319
 320           </div>
 321           <footer>
 322
 323     <div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
 324
 325         <a href="versioning.html" class="btn btn-neutral float-right" title="libmemcached Versioning" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
 326
 327
 328         <a href="constants.html" class="btn btn-neutral float-left" title="libmemcached Constants and Defaults" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
 329
 330     </div>
 331
 332
 333   <hr/>
 334
 335   <div role="contentinfo">
 336     <p>
 337         &copy; <a href="../copyright.html">Copyright</a>
 338
 339     </p>
 340   </div>
 341   Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/rtfd/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
 342
 343 </footer>
 344
 345         </div>
 346       </div>
 347
 348     </section>
 349
 350   </div>
 351
 352
 353
 354   <script type="text/javascript">
 355       jQuery(function () {
 356           SphinxRtdTheme.Navigation.enable(true);
 357       });
 358   </script>
 359
 360
 361
 362
 363
 364
 365 </body>
 366 </html>