4 <html class=
"writer-html5" lang=
"en" >
8 <meta name=
"viewport" content=
"width=device-width, initial-scale=1.0">
10 <title>libmemcached Examples
— libmemcached
1.0.99 documentation
</title>
14 <link rel=
"stylesheet" href=
"../_static/css/theme.css" type=
"text/css" />
15 <link rel=
"stylesheet" href=
"../_static/pygments.css" type=
"text/css" />
24 <script src="../_static/js/html5shiv.min.js"></script>
28 <script type=
"text/javascript" id=
"documentation_options" data-url_root=
"../" src=
"../_static/documentation_options.js"></script>
29 <script src=
"../_static/jquery.js"></script>
30 <script src=
"../_static/underscore.js"></script>
31 <script src=
"../_static/doctools.js"></script>
32 <script src=
"../_static/language_data.js"></script>
34 <script type=
"text/javascript" src=
"../_static/js/theme.js"></script>
37 <link rel=
"index" title=
"Index" href=
"../genindex.html" />
38 <link rel=
"search" title=
"Search" href=
"../search.html" />
39 <link rel=
"copyright" title=
"Copyright" href=
"../copyright.html" />
40 <link rel=
"next" title=
"libmemcached Versioning" href=
"versioning.html" />
41 <link rel=
"prev" title=
"libmemcached Constants and Defaults" href=
"constants.html" />
44 <body class=
"wy-body-for-nav">
47 <div class=
"wy-grid-for-nav">
49 <nav data-toggle=
"wy-nav-shift" class=
"wy-nav-side">
50 <div class=
"wy-side-scroll">
51 <div class=
"wy-side-nav-search" >
55 <a href=
"../index.html" class=
"icon icon-home" alt=
"Documentation Home"> libmemcached
72 <form id=
"rtd-search-form" class=
"wy-form" action=
"../search.html" method=
"get">
73 <input type=
"text" name=
"q" placeholder=
"Search docs" />
74 <input type=
"hidden" name=
"check_keywords" value=
"yes" />
75 <input type=
"hidden" name=
"area" value=
"default" />
83 <div class=
"wy-menu wy-menu-vertical" data-spy=
"affix" role=
"navigation" aria-label=
"main navigation">
90 <p class=
"caption"><span class=
"caption-text">libmemcached
</span></p>
92 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcached.html">Introduction
</a></li>
93 <li class=
"toctree-l1"><a class=
"reference internal" href=
"index.html">libmemcached API
</a></li>
94 <li class=
"toctree-l1 current"><a class=
"reference internal" href=
"index_misc.html">Misc
</a><ul class=
"current">
95 <li class=
"toctree-l2"><a class=
"reference internal" href=
"configuration.html">Configuration
</a></li>
96 <li class=
"toctree-l2"><a class=
"reference internal" href=
"constants.html">Constants
</a></li>
97 <li class=
"toctree-l2 current"><a class=
"current reference internal" href=
"#">Examples
</a></li>
98 <li class=
"toctree-l2"><a class=
"reference internal" href=
"versioning.html">Versioning
</a></li>
102 <p class=
"caption"><span class=
"caption-text">libmemcachedutil
</span></p>
104 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcachedutil.html">Introduction
</a></li>
105 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcachedutil/index.html">libmemcachedutil API
</a></li>
107 <p class=
"caption"><span class=
"caption-text">libhashkit
</span></p>
109 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libhashkit.html">Introduction
</a></li>
110 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libhashkit/index.html">libhashkit API
</a></li>
112 <p class=
"caption"><span class=
"caption-text">Client Applications
</span></p>
114 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../bin/index.html">Client Applications
</a></li>
116 <p class=
"caption"><span class=
"caption-text">Copyright
</span></p>
118 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../copyright.html">Copyright
</a></li>
128 <section data-toggle=
"wy-nav-shift" class=
"wy-nav-content-wrap">
131 <nav class=
"wy-nav-top" aria-label=
"top navigation">
133 <i data-toggle=
"wy-nav-top" class=
"fa fa-bars"></i>
134 <a href=
"../index.html">libmemcached
</a>
139 <div class=
"wy-nav-content">
141 <div class=
"rst-content">
159 <div role=
"navigation" aria-label=
"breadcrumbs navigation">
161 <ul class=
"wy-breadcrumbs">
163 <li><a href=
"../index.html" class=
"icon icon-home"></a> »</li>
165 <li><a href=
"index_misc.html">Misc
</a> »</li>
167 <li>libmemcached Examples
</li>
170 <li class=
"wy-breadcrumbs-aside">
181 <div role=
"main" class=
"document" itemscope=
"itemscope" itemtype=
"http://schema.org/Article">
182 <div itemprop=
"articleBody">
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>
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">"--SERVER=host10.example.com
"</span>
196 <span class=
"s">"--SERVER=host11.example.com
"</span>
197 <span class=
"s">"--SERVER=host10.example.com
"</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>
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>
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">"--SERVER=host10.example.com
"</span>
212 <span class=
"s">"--SERVER=host11.example.com
"</span>
213 <span class=
"s">"--SERVER=host10.example.com
"</span><span class=
"p">;
</span>
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>
217 <span class=
"n">memcached_return_t
</span> <span class=
"n">rc
</span><span class=
"p">;
</span>
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">&</span><span class=
"n">rc
</span><span class=
"p">);
</span>
221 <span class=
"c1">// .... do work
</span>
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>
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>
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
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">"foo
"</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">"value
"</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>
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>
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>
257 <p>It is best practice to always look at the return value of any operation.
</p>
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">"fudge
"</span><span class=
"p">,
</span> <span class=
"s">"son
"</span><span class=
"p">,
</span> <span class=
"s">"food
"</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>
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>
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>
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">&</span><span class=
"n">return_key_length
</span><span class=
"p">,
</span>
276 <span class=
"o">&</span><span class=
"n">return_value_length
</span><span class=
"p">,
</span> <span class=
"o">&</span><span class=
"n">flags
</span><span class=
"p">,
</span> <span class=
"o">&</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>
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>
286 <div class=
"section" id=
"see-also">
287 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
289 <div><p><em class=
"manpage"><a class=
"manpage reference external" href=
"https://linux.die.net/man/1/memcached">memcached(
1)
</a></em></p>
300 <div class=
"rst-footer-buttons" role=
"navigation" aria-label=
"footer navigation">
302 <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>
305 <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>
312 <div role=
"contentinfo">
316 © <a href=
"../copyright.html">Copyright
</a>
323 Built with
<a href=
"http://sphinx-doc.org/">Sphinx
</a> using a
325 <a href=
"https://github.com/rtfd/sphinx_rtd_theme">theme
</a>
327 provided by
<a href=
"https://readthedocs.org">Read the Docs
</a>.
339 <script type=
"text/javascript">
341 SphinxRtdTheme.Navigation.enable(true);