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]-->
9 <meta name=
"viewport" content=
"width=device-width, initial-scale=1.0">
11 <title>Generating hash values directly
— libmemcached
1.0.99 documentation
</title>
20 <script type=
"text/javascript" src=
"../_static/js/modernizr.min.js"></script>
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>
29 <script type=
"text/javascript" src=
"../_static/js/theme.js"></script>
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=
"SASL support" href=
"memcached_sasl.html" />
40 <link rel=
"prev" title=
"Set encryption key" href=
"memcached_set_encoding_key.html" />
43 <body class=
"wy-body-for-nav">
46 <div class=
"wy-grid-for-nav">
48 <nav data-toggle=
"wy-nav-shift" class=
"wy-nav-side">
49 <div class=
"wy-side-scroll">
50 <div class=
"wy-side-nav-search" >
54 <a href=
"../index.html" class=
"icon icon-home"> libmemcached
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" />
81 <div class=
"wy-menu wy-menu-vertical" data-spy=
"affix" role=
"navigation" aria-label=
"main navigation">
88 <p class=
"caption"><span class=
"caption-text">libmemcached
</span></p>
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><ul class=
"current">
96 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_internals.html">Internal Behavior
</a></li>
97 <li class=
"toctree-l3 current"><a class=
"reference internal" href=
"index_advanced_aeh.html">Authentication, Encryption
& Hashing
</a><ul class=
"current">
98 <li class=
"toctree-l4"><a class=
"reference internal" href=
"memcached_set_encoding_key.html">Set encryption key
</a></li>
99 <li class=
"toctree-l4 current"><a class=
"current reference internal" href=
"#">Generating hash values directly
</a></li>
100 <li class=
"toctree-l4"><a class=
"reference internal" href=
"memcached_sasl.html">SASL support
</a></li>
103 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_servers.html">Servers and Server Lists
</a></li>
104 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_daemon.html">Affecting the memcached Daemon
</a></li>
105 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_stats.html">Statistics
</a></li>
108 <li class=
"toctree-l2"><a class=
"reference internal" href=
"index_deprecated.html">Deprecated Functionality
</a></li>
111 <li class=
"toctree-l1"><a class=
"reference internal" href=
"index_misc.html">Misc
</a></li>
113 <p class=
"caption"><span class=
"caption-text">libmemcachedutil
</span></p>
115 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcachedutil.html">Introduction
</a></li>
116 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcachedutil/index.html">libmemcachedutil API
</a></li>
118 <p class=
"caption"><span class=
"caption-text">libhashkit
</span></p>
120 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libhashkit.html">Introduction
</a></li>
121 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libhashkit/index.html">libhashkit API
</a></li>
123 <p class=
"caption"><span class=
"caption-text">Client Applications
</span></p>
125 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../bin/index.html">Client Applications
</a></li>
127 <p class=
"caption"><span class=
"caption-text">Copyright
</span></p>
129 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../copyright.html">Copyright
</a></li>
138 <section data-toggle=
"wy-nav-shift" class=
"wy-nav-content-wrap">
141 <nav class=
"wy-nav-top" aria-label=
"top navigation">
143 <i data-toggle=
"wy-nav-top" class=
"fa fa-bars"></i>
144 <a href=
"../index.html">libmemcached
</a>
149 <div class=
"wy-nav-content">
151 <div class=
"rst-content">
169 <div role=
"navigation" aria-label=
"breadcrumbs navigation">
171 <ul class=
"wy-breadcrumbs">
173 <li><a href=
"../index.html">Docs
</a> »</li>
175 <li><a href=
"index.html">libmemcached API
</a> »</li>
177 <li><a href=
"index_advanced.html">Advanced Topics
</a> »</li>
179 <li><a href=
"index_advanced_aeh.html">Authentication, Encryption
& Hashing
</a> »</li>
181 <li>Generating hash values directly
</li>
184 <li class=
"wy-breadcrumbs-aside">
195 <div role=
"main" class=
"document" itemscope=
"itemscope" itemtype=
"http://schema.org/Article">
196 <div itemprop=
"articleBody">
198 <div class=
"section" id=
"generating-hash-values-directly">
199 <h1>Generating hash values directly
<a class=
"headerlink" href=
"#generating-hash-values-directly" title=
"Permalink to this headline">¶
</a></h1>
200 <p id=
"index-0">Hash a key value
</p>
201 <div class=
"section" id=
"synopsis">
202 <h2>SYNOPSIS
<a class=
"headerlink" href=
"#synopsis" title=
"Permalink to this headline">¶
</a></h2>
203 <p>#include
<libmemcached/memcached.h
></p>
205 <dt id=
"_CPPv416memcached_hash_t">
206 <span id=
"_CPPv316memcached_hash_t"></span><span id=
"_CPPv216memcached_hash_t"></span><span id=
"memcached_hash_t"></span><em class=
"property">type
</em><code class=
"sig-name descname">memcached_hash_t
</code><a class=
"headerlink" href=
"#_CPPv416memcached_hash_t" title=
"Permalink to this definition">¶
</a><br /></dt>
209 <dl class=
"function">
210 <dt id=
"_CPPv429memcached_generate_hash_valuePKc6size_t16memcached_hash_t">
211 <span id=
"_CPPv329memcached_generate_hash_valuePKc6size_t16memcached_hash_t"></span><span id=
"_CPPv229memcached_generate_hash_valuePKc6size_t16memcached_hash_t"></span><span id=
"memcached_generate_hash_value__cCP.s.memcached_hash_t"></span>uint32_t
<code class=
"sig-name descname">memcached_generate_hash_value
</code><span class=
"sig-paren">(
</span><em class=
"property">const
</em> char *
<em>key
</em>, size_t
<em>key_length
</em>,
<a class=
"reference internal" href=
"#_CPPv416memcached_hash_t" title=
"memcached_hash_t">memcached_hash_t
</a> <em>hash_algorithm
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv429memcached_generate_hash_valuePKc6size_t16memcached_hash_t" title=
"Permalink to this definition">¶
</a><br /></dt>
214 <dl class=
"function">
215 <dt id=
"_CPPv423memcached_generate_hashP12memcached_stPKc6size_t">
216 <span id=
"_CPPv323memcached_generate_hashP12memcached_stPKc6size_t"></span><span id=
"_CPPv223memcached_generate_hashP12memcached_stPKc6size_t"></span><span id=
"memcached_generate_hash__memcached_stP.cCP.s"></span>uint32_t
<code class=
"sig-name descname">memcached_generate_hash
</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>,
<em class=
"property">const
</em> char *
<em>key
</em>, size_t
<em>key_length
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv423memcached_generate_hashP12memcached_stPKc6size_t" title=
"Permalink to this definition">¶
</a><br /></dt>
220 <dt id=
"_CPPv422MEMCACHED_HASH_DEFAULT">
221 <span id=
"_CPPv322MEMCACHED_HASH_DEFAULT"></span><span id=
"_CPPv222MEMCACHED_HASH_DEFAULT"></span><span id=
"MEMCACHED_HASH_DEFAULT"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_DEFAULT
</code><a class=
"headerlink" href=
"#_CPPv422MEMCACHED_HASH_DEFAULT" title=
"Permalink to this definition">¶
</a><br /></dt>
225 <dt id=
"_CPPv418MEMCACHED_HASH_MD5">
226 <span id=
"_CPPv318MEMCACHED_HASH_MD5"></span><span id=
"_CPPv218MEMCACHED_HASH_MD5"></span><span id=
"MEMCACHED_HASH_MD5"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_MD5
</code><a class=
"headerlink" href=
"#_CPPv418MEMCACHED_HASH_MD5" title=
"Permalink to this definition">¶
</a><br /></dt>
230 <dt id=
"_CPPv418MEMCACHED_HASH_CRC">
231 <span id=
"_CPPv318MEMCACHED_HASH_CRC"></span><span id=
"_CPPv218MEMCACHED_HASH_CRC"></span><span id=
"MEMCACHED_HASH_CRC"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_CRC
</code><a class=
"headerlink" href=
"#_CPPv418MEMCACHED_HASH_CRC" title=
"Permalink to this definition">¶
</a><br /></dt>
235 <dt id=
"_CPPv422MEMCACHED_HASH_FNV1_64">
236 <span id=
"_CPPv322MEMCACHED_HASH_FNV1_64"></span><span id=
"_CPPv222MEMCACHED_HASH_FNV1_64"></span><span id=
"MEMCACHED_HASH_FNV1_64"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_FNV1_64
</code><a class=
"headerlink" href=
"#_CPPv422MEMCACHED_HASH_FNV1_64" title=
"Permalink to this definition">¶
</a><br /></dt>
240 <dt id=
"_CPPv423MEMCACHED_HASH_FNV1A_64">
241 <span id=
"_CPPv323MEMCACHED_HASH_FNV1A_64"></span><span id=
"_CPPv223MEMCACHED_HASH_FNV1A_64"></span><span id=
"MEMCACHED_HASH_FNV1A_64"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_FNV1A_64
</code><a class=
"headerlink" href=
"#_CPPv423MEMCACHED_HASH_FNV1A_64" title=
"Permalink to this definition">¶
</a><br /></dt>
245 <dt id=
"_CPPv422MEMCACHED_HASH_FNV1_32">
246 <span id=
"_CPPv322MEMCACHED_HASH_FNV1_32"></span><span id=
"_CPPv222MEMCACHED_HASH_FNV1_32"></span><span id=
"MEMCACHED_HASH_FNV1_32"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_FNV1_32
</code><a class=
"headerlink" href=
"#_CPPv422MEMCACHED_HASH_FNV1_32" title=
"Permalink to this definition">¶
</a><br /></dt>
250 <dt id=
"_CPPv423MEMCACHED_HASH_FNV1A_32">
251 <span id=
"_CPPv323MEMCACHED_HASH_FNV1A_32"></span><span id=
"_CPPv223MEMCACHED_HASH_FNV1A_32"></span><span id=
"MEMCACHED_HASH_FNV1A_32"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_FNV1A_32
</code><a class=
"headerlink" href=
"#_CPPv423MEMCACHED_HASH_FNV1A_32" title=
"Permalink to this definition">¶
</a><br /></dt>
255 <dt id=
"_CPPv422MEMCACHED_HASH_JENKINS">
256 <span id=
"_CPPv322MEMCACHED_HASH_JENKINS"></span><span id=
"_CPPv222MEMCACHED_HASH_JENKINS"></span><span id=
"MEMCACHED_HASH_JENKINS"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_JENKINS
</code><a class=
"headerlink" href=
"#_CPPv422MEMCACHED_HASH_JENKINS" title=
"Permalink to this definition">¶
</a><br /></dt>
260 <dt id=
"_CPPv421MEMCACHED_HASH_MURMUR">
261 <span id=
"_CPPv321MEMCACHED_HASH_MURMUR"></span><span id=
"_CPPv221MEMCACHED_HASH_MURMUR"></span><span id=
"MEMCACHED_HASH_MURMUR"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_MURMUR
</code><a class=
"headerlink" href=
"#_CPPv421MEMCACHED_HASH_MURMUR" title=
"Permalink to this definition">¶
</a><br /></dt>
265 <dt id=
"_CPPv420MEMCACHED_HASH_HSIEH">
266 <span id=
"_CPPv320MEMCACHED_HASH_HSIEH"></span><span id=
"_CPPv220MEMCACHED_HASH_HSIEH"></span><span id=
"MEMCACHED_HASH_HSIEH"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_HSIEH
</code><a class=
"headerlink" href=
"#_CPPv420MEMCACHED_HASH_HSIEH" title=
"Permalink to this definition">¶
</a><br /></dt>
270 <dt id=
"_CPPv422MEMCACHED_HASH_MURMUR3">
271 <span id=
"_CPPv322MEMCACHED_HASH_MURMUR3"></span><span id=
"_CPPv222MEMCACHED_HASH_MURMUR3"></span><span id=
"MEMCACHED_HASH_MURMUR3"></span><em class=
"property">type
</em><code class=
"sig-name descname">MEMCACHED_HASH_MURMUR3
</code><a class=
"headerlink" href=
"#_CPPv422MEMCACHED_HASH_MURMUR3" title=
"Permalink to this definition">¶
</a><br /></dt>
274 <p>Compile and link with -lmemcachedutil -lmemcached
</p>
276 <div class=
"section" id=
"description">
277 <h2>DESCRIPTION
<a class=
"headerlink" href=
"#description" title=
"Permalink to this headline">¶
</a></h2>
278 <p><a class=
"reference internal" href=
"#_CPPv429memcached_generate_hash_valuePKc6size_t16memcached_hash_t" title=
"memcached_generate_hash_value"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_generate_hash_value()
</span></code></a> allows you to hash a key using one of
279 the hash functions defined in the library. This method is provided for
280 the convenience of higher-level language bindings and is not necessary
281 for normal memcache operations.
</p>
282 <p>The allowed hash algorithm constants are listed in the manpage for
283 <a class=
"reference internal" href=
"memcached_behavior.html#_CPPv422memcached_behavior_setP12memcached_st20memcached_behavior_t8uint64_t" title=
"memcached_behavior_set"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_behavior_set()
</span></code></a>.
</p>
284 <p><a class=
"reference internal" href=
"#_CPPv423memcached_generate_hashP12memcached_stPKc6size_t" title=
"memcached_generate_hash"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_generate_hash()
</span></code></a> takes 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> structure
285 and produces the hash value that would have been generated based on the
286 defaults of
<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>.
</p>
287 <p>As of version
0.36 all hash methods have been placed into the library
288 libhashkit(
3) which is linked with libmemcached(
3). For more information please see its documentation.
</p>
290 <div class=
"section" id=
"return-value">
291 <h2>RETURN VALUE
<a class=
"headerlink" href=
"#return-value" title=
"Permalink to this headline">¶
</a></h2>
292 <p>A
32-bit integer which is the result of hashing the given key.
293 For
64-bit hash algorithms, only the least-significant
32 bits are
296 <div class=
"section" id=
"see-also">
297 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
307 <div class=
"rst-footer-buttons" role=
"navigation" aria-label=
"footer navigation">
309 <a href=
"memcached_sasl.html" class=
"btn btn-neutral float-right" title=
"SASL support" accesskey=
"n" rel=
"next">Next
<span class=
"fa fa-arrow-circle-right"></span></a>
312 <a href=
"memcached_set_encoding_key.html" class=
"btn btn-neutral float-left" title=
"Set encryption key" accesskey=
"p" rel=
"prev"><span class=
"fa fa-arrow-circle-left"></span> Previous
</a>
319 <div role=
"contentinfo">
321 © <a href=
"../copyright.html">Copyright
</a>
325 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>.
338 <script type=
"text/javascript">
340 SphinxRtdTheme.Navigation.enable(true);