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<p>
Next: <a href="Handling-alerts.html#Handling-alerts" accesskey="n" rel="next">Handling alerts</a>, Previous: <a href="Data-transfer-and-termination.html#Data-transfer-and-termination" accesskey="p" rel="prev">Data transfer and termination</a>, Up: <a href="How-to-use-GnuTLS-in-applications.html#How-to-use-GnuTLS-in-applications" accesskey="u" rel="up">How to use GnuTLS in applications</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Function-and-Data-Index.html#Function-and-Data-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="Buffered-data-transfer-1"></a>
<h3 class="section">6.8 Buffered data transfer</h3>
<p>Although <a href="Core-TLS-API.html#gnutls_005frecord_005fsend">gnutls_record_send</a> is sufficient to transmit data
to the peer, when many small chunks of data are to be transmitted
it is inefficient and wastes bandwidth due to the TLS record
overhead. In that case it is preferrable to combine the small chunks
before transmission. The following functions provide that functionality.
</p>
<dl>
<dt><a name="index-gnutls_005frecord_005fcork"></a>Function: <em>void</em> <strong>gnutls_record_cork</strong> <em>(gnutls_session_t <var>session</var>)</em></dt>
<dd><p><var>session</var>: is a <code>gnutls_session_t</code> type.
</p>
<p>If called, <code>gnutls_record_send()</code> will no longer send any records.
Any sent records will be cached until <code>gnutls_record_uncork()</code> is called.
</p>
<p>This function is safe to use with DTLS after GnuTLS 3.3.0.
</p>
<p><strong>Since:</strong> 3.1.9
</p></dd></dl>
<dl>
<dt><a name="index-gnutls_005frecord_005funcork"></a>Function: <em>int</em> <strong>gnutls_record_uncork</strong> <em>(gnutls_session_t <var>session</var>, unsigned int <var>flags</var>)</em></dt>
<dd><p><var>session</var>: is a <code>gnutls_session_t</code> type.
</p>
<p><var>flags</var>: Could be zero or <code>GNUTLS_RECORD_WAIT</code>
</p>
<p>This resets the effect of <code>gnutls_record_cork()</code> , and flushes any pending
data. If the <code>GNUTLS_RECORD_WAIT</code> flag is specified then this
function will block until the data is sent or a fatal error
occurs (i.e., the function will retry on <code>GNUTLS_E_AGAIN</code> and
<code>GNUTLS_E_INTERRUPTED</code> ).
</p>
<p>If the flag <code>GNUTLS_RECORD_WAIT</code> is not specified and the function
is interrupted then the <code>GNUTLS_E_AGAIN</code> or <code>GNUTLS_E_INTERRUPTED</code>
errors will be returned. To obtain the data left in the corked
buffer use <code>gnutls_record_check_corked()</code> .
</p>
<p><strong>Returns:</strong> On success the number of transmitted data is returned, or
otherwise a negative error code.
</p>
<p><strong>Since:</strong> 3.1.9
</p></dd></dl>
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