mariadb-columnstore-engine/writeengine/shared/we_confirmhdfsdbfile.h

/* Copyright (C) 2014 InfiniDB, Inc.

   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 Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

/** @file */

#pragma once

#include <string>

#include "IDBFileSystem.h"
#include "we_type.h"

#define EXPORT

namespace WriteEngine
{
/** @brief Encapsulates logic to confirm and finalize (or abort) changes
 *  to an HDFS db file.  Class should only be used for HDFS db files.
 *
 *  For the HDFS db files that are modified, the new version of the file
 *  may be written to a file with an alternative suffix (like .tmp file).
 *  The confirmDbFileChange() function confirms that the work is complete,
 *  and that the new temporary file (ex: *.tmp) can replace the original file.
 *  After all the columns in a table have been confirmed (through calls to
 *  confirmDbFileChange()), then endDbFileChange() should be called to finish
 *  committing or aborting all the work.
 */
class ConfirmHdfsDbFile
{
 public:
  EXPORT ConfirmHdfsDbFile();
  EXPORT ~ConfirmHdfsDbFile();

  /** @brief Confirm changes to the specified db file
   *  @param backUpFileType Backup file type to confirm.  Types:
   *    "rlc" - reallocated chunk file
   *    "tmp" - updated db file
   *  @param filename Name of db file to be confirmed.
   *  @param errMsg (out) Error msg associated with a bad return code
   *  @return Returns NO_ERROR if call is successful
   */
  EXPORT int confirmDbFileChange(const std::string& backUpFileType, const std::string& filename,
                                 std::string& errMsg) const;

  /** @brief Finalize changes to the specified db file
   *
   *  If success flag is true:
   *    The old version of the db file is deleted.
   *  If success flag is false:
   *    The old version is retained, and any temporary file with pending
   *    changes is deleted.
   *
   *  @param backUpFileType Backup file type to finalize.  Types:
   *    "rlc" - reallocated chunk file
   *    "tmp" - updated db file
   *  @param filename Name of db file to be finalized.
   *  @param success Final success/fail status of db file changes
   *  @param errMsg (out) Error msg associated with a bad return code
   *  @return Returns NO_ERROR if call is successful
   */
  EXPORT int endDbFileChange(const std::string& backUpFileType, const std::string& filename, bool success,
                             std::string& errMsg) const;

  /** @brief Confirm changes to the db files modified for tableOID
   *
   *  The HWM db file for each DBRoot, as listed in the bulk rollback meta
   *  data file (for the specified tableOID), is confirmed.
   *
   *  @param tableOID Table that has changes to be confirmed
   *  @param errMsg (out) Error msg associated with a bad return code
   *  @return Returns NO_ERROR if call is successful
   */
  EXPORT int confirmDbFileListFromMetaFile(OID tableOID, std::string& errMsg);

  /** @brief Finalize changes to the db files modified for tableOID
   *
   *  The HWM db file for each DBRoot, as listed in the bulk rollback meta
   *  data file (for the specified tableOID), is finalized.
   *
   *  If success flag is true:
   *    The old version of the db files are deleted.
   *  If success flag is false:
   *    The old versions are retained, and any temporary files with pending
   *    changes are deleted.
   *
   *  @param tableOID Table that has changes to be confirmed
   *  @param errMsg (out) Error msg associated with a bad return code
   *  @return Returns NO_ERROR if call is successful
   */
  EXPORT int endDbFileListFromMetaFile(OID tableOID, bool success, std::string& errMsg);

 private:
  void openMetaDataFile(OID tableOID, uint16_t dbRoot, std::istringstream& metaDataStream);

  void confirmDbFiles(std::istringstream& metaDataStream) const;
  void confirmColumnDbFile(const char* inBuf) const;
  void confirmDctnryStoreDbFile(const char* inBuf) const;

  void endDbFiles(std::istringstream& metaDataStream, bool success) const;
  void endColumnDbFile(const char* inBuf, bool success) const;
  void endDctnryStoreDbFile(const char* inBuf, bool success) const;

  idbdatafile::IDBFileSystem& fFs;
  std::string fMetaFileName;
};

}  // namespace WriteEngine

#undef EXPORT