# log_put

`

###

    #include <db.h>

    int
    log_put(DB_ENV *env,
        DB_LSN *lsn, const DBT *data, u_int32_t flags);

# Description

The log_put function appends records to the log. The DB_LSN of the put record is returned in the lsn argument. The flags argument may be set to one of the following values:

DB_CHECKPOINT
  The log should write a checkpoint record, recording any information necessary to make the log structures recoverable after a crash.

DB_CURLSN
  The DB_LSN of the next record to be put is returned in the lsn argument.

DB_FLUSH
  The log is forced to disk after this record is written, guaranteeing that all records with DB_LSN 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 txn_commit for more information).

  The caller is responsible for providing any necessary structure to data. (For example, in a write-ahead logging protocol, the application must understand what part of data is an operation code, what part is redo information, and what part is undo information. In addition, most transaction managers will store in data the DB_LSN of the previous log record for the same transaction, to support chaining back through the transaction's log records during undo.)

The log_put function returns a non-zero error value on failure and 0 on success.

# Errors

The log_flush function may fail and return a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  The record to be logged is larger than the maximum log record.

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 DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.

# See Also

DB_ENV->set_lg_bsize, DB_ENV->set_lg_dir, DB_ENV->set_lg_max, DB_ENV->set_lg_regionmax, log_archive, log_compare, log_file, log_flush, log_get, log_put, log_register, log_stat, and log_unregister.`

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