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<b>DB->set_feedback</b>
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<b><pre>
#include <db.h>
<p>
int
DB->set_feedback(DB *,
void (*db_feedback_fcn)(DB *dbp, int opcode, int percent));
</pre></b>
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<b>Description: DB->set_feedback</b>
<p>Some operations performed by the Berkeley DB library can take non-trivial
amounts of time. The DB->set_feedback method can be used by applications
to monitor progress within these operations. When an operation is
likely to take a long time, Berkeley DB will call the specified callback
function with progress information.</p>
<p>It is up to the callback function to display this information in an
appropriate manner.</p>
<p>The DB->set_feedback method may be called at any time during the life of the
application.</p>
<p>The DB->set_feedback method
returns a non-zero error value on failure
and 0 on success.
</p>
<b>Parameters</b> <br>
<b>db_feedback_fcn</b><ul compact><li>The <b>db_feedback_fcn</b> parameter is the application-specified
feedback function called to report Berkeley DB operation progress. The
callback function must take three parameters:
<br>
<b><b>db</b></b><ul compact><li>The <b>db</b> parameter is a reference to the enclosing database.</ul>
<b><b>opcode</b></b><ul compact><li>The <b>opcode</b> parameter is an operation code. The <b>opcode</b>
parameter may take on any of the following values:
<br>
<b><a name="DB_UPGRADE">DB_UPGRADE</a></b><ul compact><li>The underlying database is being upgraded.</ul>
<b><a name="DB_VERIFY">DB_VERIFY</a></b><ul compact><li>The underlying database is being verified.</ul>
<br></ul>
<b><b>percent</b></b><ul compact><li>The <b>percent</b> parameter is the percent of the operation that has
been completed, specified as an integer value between 0 and 100.</ul>
<br></ul>
<p>Berkeley DB is not re-entrant. Callback functions should not attempt to make
library calls (for example, to release locks or close open handles).
Re-entering Berkeley DB is not guaranteed to work correctly, and the results
are undefined.</p>
<br>
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<br><b>Class</b>
<a href="../api_c/db_class.html">DB</a>
<br><b>See Also</b>
<a href="../api_c/db_list.html">Databases and Related Methods</a>
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