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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2010 David Shrewsbury <shrewsbury.dave@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Declaration of a class used to read the GPB messages written
* by transaction_writer.
*/
#pragma once
#include <string>
#include <google/protobuf/io/zero_copy_stream_impl.h>
#include <drizzled/message/transaction.pb.h>
class TransactionFileReader
{
public:
TransactionFileReader();
~TransactionFileReader();
/**
* Open the given transaction log file.
*
* @param filename Name of the file to open
* @param start_pos Position within the file to begin reading
*
* @retval true Success
* @retval false Failure
*/
bool openFile(const std::string &filename, int start_pos = 0);
/**
* Read in next Transaction message and checksum.
*
* @note Error message will be "EOF" when end-of-file is reached.
*
* @param transaction Storage for the Transaction message
* @param checksum Storage for the checksum value
*
* @retval true Success
* @retval false Failure or EOF
*/
bool getNextTransaction(drizzled::message::Transaction &transaction,
uint32_t *checksum);
/**
* Perform a checksum of the last read transaction message.
*/
uint32_t checksumLastReadTransaction();
/**
* Get the error message from the last failed operation.
*/
const std::string& getErrorString() const
{
return error;
}
private:
int file;
char *buffer;
char *temp_buffer;
uint32_t previous_length;
std::string error;
google::protobuf::io::ZeroCopyInputStream *raw_input;
};
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