git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/memcached_callback.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>Setting callbacks &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="Use custom allocators for embedded usage" href="memcached_memory_allocators.html" />
  40     <link rel="prev" title="Behaviors of the library" href="memcached_behavior.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 current"><a class="reference internal" href="index.html">libmemcached API</a><ul class="current">
  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 current"><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"><a class="reference internal" href="index_misc.html">Misc</a><ul>
 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"><a class="reference internal" href="examples.html">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.html">libmemcached API</a> &raquo;</li>
 191
 192           <li><a href="index_advanced.html">Advanced Topics</a> &raquo;</li>
 193
 194           <li><a href="index_advanced_internals.html">Internal Behavior</a> &raquo;</li>
 195
 196       <li>Setting callbacks</li>
 197
 198
 199       <li class="wy-breadcrumbs-aside">
 200
 201
 202
 203       </li>
 204
 205   </ul>
 206
 207
 208   <hr/>
 209 </div>
 210           <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
 211            <div itemprop="articleBody">
 212
 213   <div class="section" id="setting-callbacks">
 214 <h1>Setting callbacks<a class="headerlink" href="#setting-callbacks" title="Permalink to this headline">¶</a></h1>
 215 <p>Get and set a callback</p>
 216 <div class="section" id="synopsis">
 217 <span id="index-0"></span><h2>SYNOPSIS<a class="headerlink" href="#synopsis" title="Permalink to this headline">¶</a></h2>
 218 <dl class="simple">
 219 <dt>#include &lt;libmemcached/memcached.h&gt;</dt><dd><p>Compile and link with -lmemcached</p>
 220 </dd>
 221 </dl>
 222 <dl class="function">
 223 <dt id="_CPPv422memcached_callback_setP12memcached_st20memcached_callback_tPKv">
 224 <span id="_CPPv322memcached_callback_setP12memcached_st20memcached_callback_tPKv"></span><span id="_CPPv222memcached_callback_setP12memcached_st20memcached_callback_tPKv"></span><span id="memcached_callback_set__memcached_stP.memcached_callback_t.voidCP"></span><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> <code class="sig-name descname">memcached_callback_set</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <a class="reference internal" href="#_CPPv420memcached_callback_t" title="memcached_callback_t">memcached_callback_t</a> <em>flag</em>, <em class="property">const</em> void *<em>data</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv422memcached_callback_setP12memcached_st20memcached_callback_tPKv" title="Permalink to this definition">¶</a><br /></dt>
 225 <dd></dd></dl>
 226
 227 <dl class="function">
 228 <dt id="_CPPv422memcached_callback_getP12memcached_st20memcached_callback_tP18memcached_return_t">
 229 <span id="_CPPv322memcached_callback_getP12memcached_st20memcached_callback_tP18memcached_return_t"></span><span id="_CPPv222memcached_callback_getP12memcached_st20memcached_callback_tP18memcached_return_t"></span><span id="memcached_callback_get__memcached_stP.memcached_callback_t.memcached_return_tP"></span>void *<code class="sig-name descname">memcached_callback_get</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <a class="reference internal" href="#_CPPv420memcached_callback_t" title="memcached_callback_t">memcached_callback_t</a> <em>flag</em>, <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> *<em>error</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv422memcached_callback_getP12memcached_st20memcached_callback_tP18memcached_return_t" title="Permalink to this definition">¶</a><br /></dt>
 230 <dd></dd></dl>
 231
 232 <dl class="type">
 233 <dt id="c.memcached_callback_t">
 234 enum <a class="reference internal" href="#c.memcached_callback_t" title="memcached_callback_t">memcached_callback_t</a> <code class="sig-name descname">memcached_callback_t</code><a class="headerlink" href="#c.memcached_callback_t" title="Permalink to this definition">¶</a></dt>
 235 <dd></dd></dl>
 236
 237 <dl class="enum">
 238 <dt id="_CPPv420memcached_callback_t">
 239 <span id="_CPPv320memcached_callback_t"></span><span id="_CPPv220memcached_callback_t"></span><em class="property">enum </em><code class="sig-name descname">memcached_callback_t</code><a class="headerlink" href="#_CPPv420memcached_callback_t" title="Permalink to this definition">¶</a><br /></dt>
 240 <dd><dl class="enumerator">
 241 <dt id="_CPPv4N20memcached_callback_t35MEMCACHED_CALLBACK_CLEANUP_FUNCTIONE">
 242 <span id="_CPPv3N20memcached_callback_t35MEMCACHED_CALLBACK_CLEANUP_FUNCTIONE"></span><span id="_CPPv2N20memcached_callback_t35MEMCACHED_CALLBACK_CLEANUP_FUNCTIONE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_CLEANUP_FUNCTION</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t35MEMCACHED_CALLBACK_CLEANUP_FUNCTIONE" title="Permalink to this definition">¶</a><br /></dt>
 243 <dd><p>When <a class="reference internal" href="memcached_delete.html#_CPPv416memcached_deleteP12memcached_stPKc6size_t6time_t" title="memcached_delete"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_delete()</span></code></a> is called this function will be executed. At
 244 the point of its execution all connections are closed.</p>
 245 </dd></dl>
 246
 247 <dl class="enumerator">
 248 <dt id="_CPPv4N20memcached_callback_t33MEMCACHED_CALLBACK_CLONE_FUNCTIONE">
 249 <span id="_CPPv3N20memcached_callback_t33MEMCACHED_CALLBACK_CLONE_FUNCTIONE"></span><span id="_CPPv2N20memcached_callback_t33MEMCACHED_CALLBACK_CLONE_FUNCTIONE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_CLONE_FUNCTION</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t33MEMCACHED_CALLBACK_CLONE_FUNCTIONE" title="Permalink to this definition">¶</a><br /></dt>
 250 <dd><p>When <a class="reference internal" href="memcached_delete.html#_CPPv416memcached_deleteP12memcached_stPKc6size_t6time_t" title="memcached_delete"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_delete()</span></code></a> is called this function will be executed.
 251 At the point of its execution all connections are closed.</p>
 252 </dd></dl>
 253
 254 <dl class="enumerator">
 255 <dt id="_CPPv4N20memcached_callback_t29MEMCACHED_CALLBACK_PREFIX_KEYE">
 256 <span id="_CPPv3N20memcached_callback_t29MEMCACHED_CALLBACK_PREFIX_KEYE"></span><span id="_CPPv2N20memcached_callback_t29MEMCACHED_CALLBACK_PREFIX_KEYE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_PREFIX_KEY</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t29MEMCACHED_CALLBACK_PREFIX_KEYE" title="Permalink to this definition">¶</a><br /></dt>
 257 <dd><p>See <a class="reference internal" href="#_CPPv4N20memcached_callback_t28MEMCACHED_CALLBACK_NAMESPACEE" title="memcached_callback_t::MEMCACHED_CALLBACK_NAMESPACE"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_CALLBACK_NAMESPACE</span></code></a></p>
 258 </dd></dl>
 259
 260 <dl class="enumerator">
 261 <dt id="_CPPv4N20memcached_callback_t28MEMCACHED_CALLBACK_NAMESPACEE">
 262 <span id="_CPPv3N20memcached_callback_t28MEMCACHED_CALLBACK_NAMESPACEE"></span><span id="_CPPv2N20memcached_callback_t28MEMCACHED_CALLBACK_NAMESPACEE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_NAMESPACE</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t28MEMCACHED_CALLBACK_NAMESPACEE" title="Permalink to this definition">¶</a><br /></dt>
 263 <dd><p>You can set a value which will be used to create a domain for your keys.
 264 The value specified here will be prefixed to each of your keys. The value can
 265 not be greater then <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_PREFIX_KEY_MAX_SIZE</span></code> - 1 and will
 266 reduce <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_MAX_KEY</span></code> by the value of your key.</p>
 267 <p>The prefix key is only applied to the primary key, not the master key.
 268 <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_FAILUREE" title="MEMCACHED_FAILURE"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_FAILURE</span></code></a> will be returned if no key is set. In the case of
 269 a key which is too long, <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t26MEMCACHED_BAD_KEY_PROVIDEDE" title="MEMCACHED_BAD_KEY_PROVIDED"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_BAD_KEY_PROVIDED</span></code></a> will be returned.</p>
 270 <p>If you set a value with the value being NULL then the prefix key is disabled.</p>
 271 </dd></dl>
 272
 273 <dl class="enumerator">
 274 <dt id="_CPPv4N20memcached_callback_t28MEMCACHED_CALLBACK_USER_DATAE">
 275 <span id="_CPPv3N20memcached_callback_t28MEMCACHED_CALLBACK_USER_DATAE"></span><span id="_CPPv2N20memcached_callback_t28MEMCACHED_CALLBACK_USER_DATAE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_USER_DATA</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t28MEMCACHED_CALLBACK_USER_DATAE" title="Permalink to this definition">¶</a><br /></dt>
 276 <dd><p>This allows you to store a pointer to a specific piece of data. This can be
 277 retrieved from inside of <a class="reference internal" href="memcached_get.html#_CPPv423memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t" title="memcached_fetch_execute"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_execute()</span></code></a>. Cloning a
 278 <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> will copy the pointer to the clone.</p>
 279 </dd></dl>
 280
 281 <dl class="enumerator">
 282 <dt id="_CPPv4N20memcached_callback_t34MEMCACHED_CALLBACK_MALLOC_FUNCTIONE">
 283 <span id="_CPPv3N20memcached_callback_t34MEMCACHED_CALLBACK_MALLOC_FUNCTIONE"></span><span id="_CPPv2N20memcached_callback_t34MEMCACHED_CALLBACK_MALLOC_FUNCTIONE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_MALLOC_FUNCTION</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t34MEMCACHED_CALLBACK_MALLOC_FUNCTIONE" title="Permalink to this definition">¶</a><br /></dt>
 284 <dd><div class="deprecated">
 285 <p><span class="versionmodified deprecated">Deprecated since version &lt;0.32: </span>Use <a class="reference internal" href="memcached_memory_allocators.html#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title="memcached_set_memory_allocators"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_set_memory_allocators</span></code></a> instead.</p>
 286 </div>
 287 </dd></dl>
 288
 289 <dl class="enumerator">
 290 <dt id="_CPPv4N20memcached_callback_t35MEMCACHED_CALLBACK_REALLOC_FUNCTIONE">
 291 <span id="_CPPv3N20memcached_callback_t35MEMCACHED_CALLBACK_REALLOC_FUNCTIONE"></span><span id="_CPPv2N20memcached_callback_t35MEMCACHED_CALLBACK_REALLOC_FUNCTIONE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_REALLOC_FUNCTION</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t35MEMCACHED_CALLBACK_REALLOC_FUNCTIONE" title="Permalink to this definition">¶</a><br /></dt>
 292 <dd><div class="deprecated">
 293 <p><span class="versionmodified deprecated">Deprecated since version &lt;0.32: </span>Use <a class="reference internal" href="memcached_memory_allocators.html#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title="memcached_set_memory_allocators"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_set_memory_allocators</span></code></a> instead.</p>
 294 </div>
 295 </dd></dl>
 296
 297 <dl class="enumerator">
 298 <dt id="_CPPv4N20memcached_callback_t32MEMCACHED_CALLBACK_FREE_FUNCTIONE">
 299 <span id="_CPPv3N20memcached_callback_t32MEMCACHED_CALLBACK_FREE_FUNCTIONE"></span><span id="_CPPv2N20memcached_callback_t32MEMCACHED_CALLBACK_FREE_FUNCTIONE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_FREE_FUNCTION</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t32MEMCACHED_CALLBACK_FREE_FUNCTIONE" title="Permalink to this definition">¶</a><br /></dt>
 300 <dd><div class="deprecated">
 301 <p><span class="versionmodified deprecated">Deprecated since version &lt;0.32: </span>Use <a class="reference internal" href="memcached_memory_allocators.html#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title="memcached_set_memory_allocators"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_set_memory_allocators</span></code></a> instead.</p>
 302 </div>
 303 </dd></dl>
 304
 305 <dl class="enumerator">
 306 <dt id="_CPPv4N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILUREE">
 307 <span id="_CPPv3N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILUREE"></span><span id="_CPPv2N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILUREE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_GET_FAILURE</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILUREE" title="Permalink to this definition">¶</a><br /></dt>
 308 <dd><p>This function implements the read through cache behavior. On failure of retrieval this callback will be called.</p>
 309 <p>You are responsible for populating the result object provided. This result object will then be stored in the server and returned to the calling process.</p>
 310 <p>You must clone the <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> in order to
 311 make use of it. The value will be stored only if you return
 312 <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_SUCCESSE" title="MEMCACHED_SUCCESS"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_SUCCESS</span></code></a> or <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t18MEMCACHED_BUFFEREDE" title="MEMCACHED_BUFFERED"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_BUFFERED</span></code></a>. Returning
 313 <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t18MEMCACHED_BUFFEREDE" title="MEMCACHED_BUFFERED"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_BUFFERED</span></code></a> will cause the object to be buffered and not sent
 314 immediately (if this is the default behavior based on your connection setup
 315 this will happen automatically).</p>
 316 <p>The prototype for this is:</p>
 317 <dl class="type">
 318 <dt id="_CPPv4N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILURE21memcached_trigger_keyE">
 319 <span id="_CPPv3N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILURE21memcached_trigger_keyE"></span><span id="_CPPv2N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILURE21memcached_trigger_keyE"></span><span id="memcached_callback_t::MEMCACHED_CALLBACK_GET_FAILURE::memcached_trigger_key"></span><em class="property">typedef </em><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> (*<code class="sig-name descname">memcached_trigger_key</code>)<span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *ptr, char *key, size_t key_length, <a class="reference internal" href="memcached_result_st.html#_CPPv419memcached_result_st" title="memcached_result_st">memcached_result_st</a> *result<span class="sig-paren">)</span><a class="headerlink" href="#_CPPv4N20memcached_callback_t30MEMCACHED_CALLBACK_GET_FAILURE21memcached_trigger_keyE" title="Permalink to this definition">¶</a><br /></dt>
 320 <dd></dd></dl>
 321
 322 </dd></dl>
 323
 324 <dl class="enumerator">
 325 <dt id="_CPPv4N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGERE">
 326 <span id="_CPPv3N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGERE"></span><span id="_CPPv2N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGERE"></span><em class="property">enumerator </em><code class="sig-name descname">MEMCACHED_CALLBACK_DELETE_TRIGGER</code><a class="headerlink" href="#_CPPv4N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGERE" title="Permalink to this definition">¶</a><br /></dt>
 327 <dd><p>This function implements a trigger upon successful deletion of a key. The memcached_st structure will need to be cloned in order to make use of it.</p>
 328 <p>The prototype for this is:</p>
 329 <dl class="type">
 330 <dt id="_CPPv4N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGER28memcached_trigger_delete_keyE">
 331 <span id="_CPPv3N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGER28memcached_trigger_delete_keyE"></span><span id="_CPPv2N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGER28memcached_trigger_delete_keyE"></span><span id="memcached_callback_t::MEMCACHED_CALLBACK_DELETE_TRIGGER::memcached_trigger_delete_key"></span><em class="property">typedef </em><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> (*<code class="sig-name descname">memcached_trigger_delete_key</code>)<span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *ptr, char *key, size_t key_length<span class="sig-paren">)</span><a class="headerlink" href="#_CPPv4N20memcached_callback_t33MEMCACHED_CALLBACK_DELETE_TRIGGER28memcached_trigger_delete_keyE" title="Permalink to this definition">¶</a><br /></dt>
 332 <dd></dd></dl>
 333
 334 </dd></dl>
 335
 336 </dd></dl>
 337
 338 </div>
 339 <div class="section" id="description">
 340 <h2>DESCRIPTION<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
 341 <p><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">libmemcached</span></code> can have callbacks set key execution points. These either
 342 provide function calls at points in the code, or return pointers to
 343 structures for particular usages.</p>
 344 <p><a class="reference internal" href="#_CPPv422memcached_callback_getP12memcached_st20memcached_callback_tP18memcached_return_t" title="memcached_callback_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_callback_get()</span></code></a> takes a callback flag and returns the
 345 structure or function set by <a class="reference internal" href="#_CPPv422memcached_callback_setP12memcached_st20memcached_callback_tPKv" title="memcached_callback_set"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_callback_set()</span></code></a>.</p>
 346 <p><a class="reference internal" href="#_CPPv422memcached_callback_setP12memcached_st20memcached_callback_tPKv" title="memcached_callback_set"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_callback_set()</span></code></a> changes the function/structure assigned by a
 347 callback flag. No connections are reset.</p>
 348 <p>You can use <a class="reference internal" href="#_CPPv4N20memcached_callback_t28MEMCACHED_CALLBACK_USER_DATAE" title="MEMCACHED_CALLBACK_USER_DATA"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_CALLBACK_USER_DATA</span></code></a> to provide custom context
 349 if required for any of the callbacks.</p>
 350 </div>
 351 <div class="section" id="return-value">
 352 <h2>RETURN VALUE<a class="headerlink" href="#return-value" title="Permalink to this headline">¶</a></h2>
 353 <p><a class="reference internal" href="#_CPPv422memcached_callback_getP12memcached_st20memcached_callback_tP18memcached_return_t" title="memcached_callback_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_callback_get()</span></code></a> return the function or structure that was
 354 provided. Upon error, nothing is set, null is returned, and the
 355 <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_return_t</span></code></a> argument is set to <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_FAILUREE" title="MEMCACHED_FAILURE"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_FAILURE</span></code></a>.</p>
 356 <p><a class="reference internal" href="#_CPPv422memcached_callback_setP12memcached_st20memcached_callback_tPKv" title="memcached_callback_set"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_callback_set()</span></code></a> returns <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_SUCCESSE" title="MEMCACHED_SUCCESS"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_SUCCESS</span></code></a> upon
 357 successful setting, otherwise <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_FAILUREE" title="MEMCACHED_FAILURE"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_FAILURE</span></code></a> on error.</p>
 358 </div>
 359 <div class="section" id="see-also">
 360 <h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
 361 </div>
 362 </div>
 363
 364
 365            </div>
 366
 367           </div>
 368           <footer>
 369
 370     <div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
 371
 372         <a href="memcached_memory_allocators.html" class="btn btn-neutral float-right" title="Use custom allocators for embedded usage" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
 373
 374
 375         <a href="memcached_behavior.html" class="btn btn-neutral float-left" title="Behaviors of the library" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
 376
 377     </div>
 378
 379
 380   <hr/>
 381
 382   <div role="contentinfo">
 383     <p>
 384         &copy; <a href="../copyright.html">Copyright</a>
 385
 386     </p>
 387   </div>
 388   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>.
 389
 390 </footer>
 391
 392         </div>
 393       </div>
 394
 395     </section>
 396
 397   </div>
 398
 399
 400
 401   <script type="text/javascript">
 402       jQuery(function () {
 403           SphinxRtdTheme.Navigation.enable(true);
 404       });
 405   </script>
 406
 407
 408
 409
 410
 411
 412 </body>
 413 </html>