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kvs


			
				
					
						
						
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    <h1>KVS</h1>
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<main>
    <section>

<h3>INTRO</h3>

   <p>This module is used to manage different KV backends to your cloud of Erlang apps.
      This is an unified abstraction layer to several databases: <b>redis</b>,
      <b>mongo</b>, <b>mnesia</b>, <b>riak</b>, <b>aerospike</b>.</p>

        <p><blockquote><p><ul>
            <li><b><a href="#dir">dir/0</a></b> &mdash; table list.</li>
            <li><b><a href="#ver">ver/0</a></b> &mdash; KVS version.</li>
            <li><b><a href="#seq">seq/2</a></b> &mdash; generate new sequence id for table.</li>
            <li><b><a href="#count">count/1</a></b> &mdash; records in table.</li>
            <li><b><a href="#put">put/1</a></b> &mdash; put record using element 2 as key.</li>
            <li><b><a href="#get">get/2</a></b> &mdash; get record by key from table.</li>
            <li><b><a href="#delete">delete/1</a></b> &mdash; delete record from table.</li>
            <li><b><a href="#index">index/3</a></b> &mdash; index by field and its value.</li>
        </ul></p></blockquote></p>

 <p>You can change backend by setting application env. This behaves well on </p>

<figure><code>
 application:set_env(kvs,dba,store_mnesia).

</code></figure>

    </section>
    <section>

<h3>RECORDS</h3>

<figure><figcaption>KVS CORE</figcaption><code>
    #ok { data= [] :: term() }.

 #error { data= [] :: term() }.

   #cur { id=   [] :: term(),
          top=  [] :: [] | integer(),
          bot=  [] :: [] | integer(),
          dir=   0 ::  0 | 1,
          reader= [] :: [] | tuple(),
          writer= [] :: [] | tuple(),
          left=  0 :: integer(),
          right= 0 :: inetegr() }.

  #iter { id=   [] :: [] | integer(),
          prev= [] :: [] | integer(),
          next= [] :: [] | integer()).

</code></figure>

<p><ul>
<li>id &mdash; Unique key of the cursor.</li>
</ul></p>

    </section>
    <section>

<h3>CONFIG</h3>

<p>In sys.config you should specify kvs backend and list of modules
   containing <b>metainfo/0</b> exported function.</p>

<figure><code>
  [{kvs, [{dba, store_mnesia},
          {schema, [kvs]} ]}].

</code></figure>

    </section>
    <section>

<p>This module may refer to:
<a href="http://erlang.org/doc/man/mnesia.html">mnesia</a></b>,
<a href="kvs_stream.htm"><b>kvs_stream</b></a>.
</p>

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