=head1 NAME

RocksDB::WriteBatch - rocksdb::WriteBatch object

=head1 SYNOPSIS

  use RocksDB;

  my $db = RocksDB->new('/path/to/db');
  $db->update(sub {
      my $batch = shift;
      $batch->put(key => 'value');
      $batch->delete('key');
  });

  my $batch = RocksDB::WriteBatch->new;
  $batch->put(key => 'value');
  $batch->clear;
  $batch->delete('key');
  $batch->put_log_data(time());
  $db->write($batch);

=head1 DESCRIPTION

B<RocksDB::WriteBatch> is a rocksdb::WriteBatch object.

=head1 CONSTRUCTOR

=head2 C<< RocksDB::WriteBatch->new() :RocksDB::WriteBatch >>

Create and return a new RocksDB::WriteBatch object.

=head1 METHODS

=head2 C<< $batch->put($key :Str, $value :Str) :Undef >>

Store the mapping $key -> $value in the database.

=head2 C<< $batch->delete($key :Str) :Undef >>

If the database contains a mapping for $key, erase it.  Else do nothing.

=head2 C<< $batch->put_log_data($blob :Str) :Undef >>

Append a blob of arbitrary size to the records in this batch. The blob will
be stored in the transaction log but not in any other file. In particular,
it will not be persisted to the SST files. When iterating over this
WriteBatch, WriteBatchHandler::log_data will be called with the contents
of the blob as it is encountered. Blobs, puts, deletes, and merges will be
encountered in the same order in thich they were inserted. The blob will
NOT consume sequence number(s) and will NOT increase the count of the batch

Example application: add timestamps to the transaction log for use in
replication.

See also L<RocksDB::WriteBatchHandler>.

=head2 C<< $batch->clear() :Undef >>

Clear all updates buffered in this batch.

=head2 C<< $batch->count() :Int >>

Returns the number of updates in the batch.

=head2 C<< $batch->data() :Str >>

Retrieve the serialized version of this batch.

=head2 C<< $batch->iterate($handler :RocksDB::WriteBatchHandler) :Undef >>

Support for iterating over the contents of a batch.

See L<RocksDB::WriteBatchHandler>.

=head1 SEE ALSO

L<RocksDB>, L<RocksDB::WriteBatchHandler>

=head1 AUTHOR

Jiro Nishiguchi E<lt>jiro@cpan.orgE<gt>

=cut