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Next: <a href="Allocation-handler.html#Allocation-handler" accesskey="n" rel="next">Allocation handler</a>, Up: <a href="Handler-Functions.html#Handler-Functions" accesskey="u" rel="up">Handler Functions</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Progress-handler-1"></a>
<h3 class="section">4.1 Progress handler</h3>

<p>It is often useful to retrieve some feedback while long running
operations are performed.
</p>
<dl>
<dt><a name="index-gcry_005fhandler_005fprogress_005ft"></a>Data type: <strong>gcry_handler_progress_t</strong></dt>
<dd><p>Progress handler functions have to be of the type
<code>gcry_handler_progress_t</code>, which is defined as:
</p>
<p><code>void (*gcry_handler_progress_t) (void *, const char *, int, int, int)</code>
</p></dd></dl>

<p>The following function may be used to register a handler function for
this purpose.
</p>
<dl>
<dt><a name="index-gcry_005fset_005fprogress_005fhandler"></a>Function: <em>void</em> <strong>gcry_set_progress_handler</strong> <em>(gcry_handler_progress_t <var>cb</var>, void *<var>cb_data</var>)</em></dt>
<dd>
<p>This function installs <var>cb</var> as the &lsquo;Progress handler&rsquo; function.
It may be used only during initialization.  <var>cb</var> must be defined
as follows:
</p>
<div class="example">
<pre class="example">void
my_progress_handler (void *<var>cb_data</var>, const char *<var>what</var>,
                     int <var>printchar</var>, int <var>current</var>, int <var>total</var>)
{
  /* Do something.  */
}
</pre></div>

<p>A description of the arguments of the progress handler function follows.
</p>
<dl compact="compact">
<dt><var>cb_data</var></dt>
<dd><p>The argument provided in the call to <code>gcry_set_progress_handler</code>.
</p></dd>
<dt><var>what</var></dt>
<dd><p>A string identifying the type of the progress output.  The following
values for <var>what</var> are defined:
</p>
<dl compact="compact">
<dt><code>need_entropy</code></dt>
<dd><p>Not enough entropy is available.  <var>total</var> holds the number of
required bytes.
</p>
</dd>
<dt><code>primegen</code></dt>
<dd><p>Values for <var>printchar</var>:
</p><dl compact="compact">
<dt><code>\n</code></dt>
<dd><p>Prime generated.
</p></dd>
<dt><code>!</code></dt>
<dd><p>Need to refresh the pool of prime numbers.
</p></dd>
<dt><code>&lt;, &gt;</code></dt>
<dd><p>Number of bits adjusted.
</p></dd>
<dt><code>^</code></dt>
<dd><p>Searching for a generator.
</p></dd>
<dt><code>.</code></dt>
<dd><p>Fermat test on 10 candidates failed.
</p></dd>
<dt><code>:</code></dt>
<dd><p>Restart with a new random value.
</p></dd>
<dt><code>+</code></dt>
<dd><p>Rabin Miller test passed.
</p></dd>
</dl>

</dd>
</dl>

</dd>
</dl>
</dd></dl>




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libgcrypt11-doc 1.5.3-2ubuntu4.6 / usr / share / doc / libgcrypt11-doc / html / Progress-handler.html
