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<h1>log_put</h1>
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<h3><pre>
#include <db.h>
<p>
int
log_put(DB_ENV *env,
DB_LSN *lsn, const DBT *data, u_int32_t flags);
</pre></h3>
<h1>Description</h1>
<p>The log_put function appends records to the log. The <a href="../api_c/db_lsn.html">DB_LSN</a> of
the put record is returned in the <b>lsn</b> argument. The <b>flags</b>
argument may be set to one of the following values:
<p><dl compact>
<p><dt><a name="DB_CHECKPOINT">DB_CHECKPOINT</a><dd>The log should write a checkpoint record, recording any information
necessary to make the log structures recoverable after a crash.
<p><dt><a name="DB_CURLSN">DB_CURLSN</a><dd>The <a href="../api_c/db_lsn.html">DB_LSN</a> of the next record to be put is returned in the
<b>lsn</b> argument.
<p><dt><a name="DB_FLUSH">DB_FLUSH</a><dd>The log is forced to disk after this record is written, guaranteeing
that all records with <a href="../api_c/db_lsn.html">DB_LSN</a> values less than or equal to the
one being put are on disk before this function returns (this function
is most often used for a transaction commit, see <a href="../api_c/txn_commit.html">txn_commit</a> for
more information).
<p>The caller is responsible for providing any necessary structure to
<b>data</b>. (For example, in a write-ahead logging protocol, the
application must understand what part of <b>data</b> is an operation
code, what part is redo information, and what part is undo information.
In addition, most transaction managers will store in <b>data</b> the
<a href="../api_c/db_lsn.html">DB_LSN</a> of the previous log record for the same transaction, to
support chaining back through the transaction's log records during
undo.)
</dl>
<p>The log_put function returns a non-zero error value on failure and 0 on success.
<h1>Errors</h1>
<p>The <a href="../api_c/log_flush.html">log_flush</a> function may fail and return a non-zero error for the following conditions:
<p><dl compact>
<p><dt>EINVAL<dd>An invalid flag value or parameter was specified.
<p>The record to be logged is larger than the maximum log record.
</dl>
<p>The log_put function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions.
If a catastrophic error has occurred, the log_put function may fail and return
<a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a>, in which case all subsequent Berkeley DB calls will fail
in the same way.
<h1>See Also</h1>
<a href="../api_c/env_set_lg_bsize.html">DBENV->set_lg_bsize</a>,
<a href="../api_c/env_set_lg_max.html">DBENV->set_lg_max</a>,
<a href="../api_c/log_archive.html">log_archive</a>,
<a href="../api_c/log_compare.html">log_compare</a>,
<a href="../api_c/log_file.html">log_file</a>,
<a href="../api_c/log_flush.html">log_flush</a>,
<a href="../api_c/log_get.html">log_get</a>,
<a href="../api_c/log_put.html">log_put</a>,
<a href="../api_c/log_register.html">log_register</a>,
<a href="../api_c/log_stat.html">log_stat</a>
and
<a href="../api_c/log_unregister.html">log_unregister</a>.
</tt>
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