/* 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. */

/*
 * $Id: we_rbmetawriter.h 4450 2013-01-21 14:13:24Z rdempsey $
 */

/** @file we_rbmetawriter.h
 * Contains class to write HWM-related information used to rollback a
 * cpimport.bin job that abnormally terminated, leaving the db in an
 * inconsistent state.
 * Class was moved from bulk directory for resuse by DML as part of Shared
 * Nothing.
 */

#pragma once

#include <string>
#include <sstream>
#include <set>
#include <map>
#include <vector>
#include <boost/thread/mutex.hpp>

#include "we_type.h"
#include "brmtypes.h"
#include "we_fileop.h"

#define EXPORT

#define DBROOT_BULK_ROLLBACK_SUBDIR "bulkRollback"

namespace WriteEngine
{
class Log;

//------------------------------------------------------------------------------
/** @brief Class used to store Dictionary store file information used in backing
 * up HWM chunks "as needed".
 */
//------------------------------------------------------------------------------
struct RBChunkInfo
{
  OID fOid;             // dctnry store OID containing relevant chunk
  uint16_t fDbRoot;     // dbroot, partition, segment of file
  uint32_t fPartition;  //   containing relevant HWM chunk
  uint16_t fSegment;    //
  HWM fHwm;             // HWM block of interest
  RBChunkInfo(OID oid, uint16_t dbRoot, uint32_t partition, uint16_t segment, HWM hwm)
   : fOid(oid), fDbRoot(dbRoot), fPartition(partition), fSegment(segment), fHwm(hwm)
  {
  }
};

class RBChunkInfoCompare
{
 public:
  bool operator()(const RBChunkInfo& lhs, const RBChunkInfo& rhs) const;
};

typedef std::set<RBChunkInfo, RBChunkInfoCompare> RBChunkSet;

//------------------------------------------------------------------------------
/** @brief Class to write HWM-related information to support bulk rollbacks.
 *
 * Should cpimport.bin terminate abnormally, leaving the db in an inconsistent
 * state, then the information written by this class can be used to perform
 * a bulk rollback, to restore the db to its previous state, prior to the
 * execution of the import job.
 *
 * For SharedEveryThing:
 * Note that column segment files, carry a logical concatenation of extents,
 * so only the HWM of the last logical extent needs to be written to the meta
 * data file, as the information about where the data stops (and needs to
 * be rolled back) for the other segment files can be derived from knowing
 * the last Local HWM.
 *
 * For Shared-Nothing:
 * Column segment files only carry a logical concatenation of extents, within
 * a DBRoot.  So the HWM of the last logical extent in each DBRoot (for a PM)
 * must be written to the meta data file.  The information about where the data
 * stops (and needs to be rolled back) for the other segment files within a
 * DBRoot can be derived from knowing the last Local HWM per DBRoot.
 * One meta data control file is created for each DBRoot, and in fact, the
 * meta file is created under the corresponding DBRoot directory.
 *
 * In the case of dictionary store segment files, each store file is
 * independent of the other segment store files for the same OID.  So for
 * dictionary store segment files, the HWM must be written for each segment
 * file in the last partition for each DBRoot.
 *
 * API Usage:
 * Public functions would typically be called in the following order:
 *   1. Create and initialize Bulk Rollback Metadata object:
 *        RBMetaWriter()
 *        init()
 *   2. Create primary meta data file (see note below);
 *        openMetaFile()
 *        writeColumnMetaData()
 *        writeDictionaryStoreMetaData()
 *        writeDictionaryStoreMetaNoDataMarker()
 *        closeMetaFile()
 *   3. Backup necessary HWM chunks to backup chunk files:
 *        a. backupColumnHWMChunk()
 *        b. backupDctnryHWMChunk()
 *   4. Delete meta data file and HWM chunk files at end of successful job:
 *        deleteFile()
 *   5. Delete Bulk Rollback Metadata object:
 *        ~RBMetaWriter()
 *
 * Steps 2 and 3a have been replaced with a single call to saveBulkRollback-
 * MetaData().  This is a helper function that takes care of all the calls in
 * steps 2 and 3a.  If an error should occur in saveBulkRollbackMetaData(),
 * closeMetaFile() will automatically be called to close the meta data file.
 *
 * backupDctnryHWMChunk() must be thread-safe as step 3b can be executed in
 * parallel by several threads for different dictionary columns.
 */
//------------------------------------------------------------------------------
class RBMetaWriter : public WeUIDGID
{
 public:
  /** @brief RBMetaWriter constructor
   * @param appDesc Description of application that is using RBMetaWriter
   * @param logger Logger to be used for logging messages.
   */
  EXPORT RBMetaWriter(const std::string& appDesc, Log* logger);

  /** @brief RBMetaWriter destructor
   */
  EXPORT ~RBMetaWriter()
  {
    closeMetaFile();
  }

  /** @brief Initialize this RBMetaWriter object
   * Warning: This function may throw a WeException.
   *
   * @param tableOID OID of the table whose state is to be saved.
   * @param tableName Name of the table associated with tableOID.
   */
  EXPORT void init(OID tableOID, const std::string& tableName);

  /** @brief Make a backup copy of the specified HWM dictionary store chunk.
   * This operation only applies to compressed columns.  Backup may not be
   * necessary.  Return value indicates whether the specified file needs to
   * be backed up or not.
   * Warning: This function may throw a WeException.
   *
   * This function is thread-safe since concurrent calls could be made by
   * different threads, each for a different dictionary column.
   *
   * @param dctnryOID column OID to be saved
   * @param dbRoot current dbRoot of last local HWM for columnOID
   * @param partition current partition of last local HWM for columnOID
   * @param segment current segment of last local HWM for columnOID
   * @return Indicates whether it is necessary to perform backup
   */
  EXPORT bool backupDctnryHWMChunk(OID dctnryOID, uint16_t dbRoot, uint32_t partition, uint16_t segment);

  /** @brief Delete the rollback meta files associated with this table
   * Warning: This function may throw a WeException.
   */
  EXPORT void deleteFile();

  /** @brief Helper function that creates the primary meta data file.
   * Warning: This function may throw a WeException.
   *
   * See class description for more details.
   * @param columns Vector of column information.  The dataFile member in
   *        each columns entry should be filled in with HWM information about
   *        the start extent where rows will be added.  This information is
   *        needed so that the HWM chunk in that extent can be backed up.
   * @param dctnryStoreOids Vector of dictionary store OID associated with
   *        columns vector.  dctnryStoreOid[n] should be 0 if columns[n] is
   *        not a dictionary column.
   * @param dbRootHwmInfoVecCol Vector of EmDbRootHWMInfo_v objects obtained
   *        from multiple calls to DBRM::getDbRootHWMInfo().  There is one
   *        EmDbRootHWMInfo_v entry per column.  Each
   *        EmDbRootHWMInfo_v object carries a vector of DBRoot, HWM, etc
   *        objects representing the current HWM extents for a column's
   *        DBRoots on the local PM.
   */
  EXPORT void saveBulkRollbackMetaData(const std::vector<Column>& columns,
                                       const std::vector<OID>& dctnryStoreOids,
                                       const std::vector<BRM::EmDbRootHWMInfo_v>& dbRootHWMInfoVecCol);

  /** @brief Verify that specified version record is for Version 3 */
  static bool verifyVersion3(const char* versionRec);

  /** @brief Verify that specified version record is for Version 4 */
  static bool verifyVersion4(const char* versionRec);

  /** @brief Verify that specified record type is a Column1 record */
  static bool verifyColumn1Rec(const char* recType);

  /** @brief Verify that specified record type is a Column2 record */
  static bool verifyColumn2Rec(const char* recType);

  /** @brief Verify that specified record type is a DStore1 record */
  static bool verifyDStore1Rec(const char* recType);

  /** @brief Verify that specified record type is a DStore2 record */
  static bool verifyDStore2Rec(const char* recType);

 private:
  // disable copy constructor and assignment operator
  RBMetaWriter(const RBMetaWriter&);
  RBMetaWriter& operator=(const RBMetaWriter&);

  // Make a backup copy of the specified HWM column chunk.
  // This operation only applies to compressed columns.
  // Warning: This function may throw a WeException.
  //   columnOID column OID to be saved
  //   dbRoot current dbRoot of last local HWM for columnOID
  //   partition current partition of last local HWM for columnOID
  //   segment current segment of last local HWM for columnOID
  //   lastLocalHwm current last local for column OID
  void backupColumnHWMChunk(OID columnOID, uint16_t dbRoot, uint32_t partition, uint16_t segment,
                            HWM lastLocalHwm);

  // This function must be thread-safe since it is called directly by
  // backupDctnryHWMChunk().  Employed by non-hdfs.
  void backupHWMChunk(bool bColumnFile, OID columnOID, uint16_t dbRoot, uint32_t partition, uint16_t segment,
                      HWM lastLocalHwm);

  // This function must be thread-safe since it is called directly by
  // backupDctnryHWMFile().   Employed by hdfs.
  void backupHWMFile(bool bColumnFile, OID columnOID, uint16_t dbRoot, uint32_t partition, uint16_t segment,
                     HWM lastLocalHwm);

  // Close the current meta data file.
  EXPORT void closeMetaFile();

  void createSubDir(const std::string& metaFileName);
  void deleteSubDir(const std::string& metaFileName);
  int getSubDirPath(const uint16_t dbRoot, std::string& subDirPath) const;

  // Open a meta data file to save HWM bulk rollback info for tableOID
  // Warning: This function may throw a WeException.
  //   dbRoot is the DBRoot of interest for the applicable table.
  std::string openMetaFile(uint16_t dbRoot);

  // Rename temporary metadata control file(s) to the permanent name.
  // Filenames are taken from fMetaFileNames.
  // Warning: This function may throw a WeException.
  void renameMetaFile();

  // Save column meta data to the currently open file.
  // This is the Shared-Nothing version of this function.
  // Warning: This function may throw a WeException.
  //   metaFileName    name of metafile to be written
  //   columnOID       column OID to be saved
  //   dbRoot          current dbRoot of last local HWM for columnOID
  //   partition       current partition of last local HWM for columnOID
  //   segment         current segment of last local HWM for columnOID
  //   lastLocalHwm    current last local for column OID
  //   colType         type of columnOID
  //   colTypeName     type name of columnOID
  //   colWidth        width (in bytes) of columnOID
  //   compressionType compression type
  void writeColumnMetaData(const std::string& metaFileName, bool withHWM, OID columnOID, uint16_t dbRoot,
                           uint32_t partition, uint16_t segment, HWM lastLocalHwm,
                           execplan::CalpontSystemCatalog::ColDataType colType,
                           const std::string& colTypeName, int colWidth, int compressionType);

  // Save dictionary store meta data to the currently open file.
  // This is the Shared-Nothing version of this function.
  //   dictionaryStoreOID dictionary store OID to be saved
  //   dbRoot dbRoot of store file
  //   partition partition of store file
  //   segment segment of store file
  //   localHwm current local HWM for specified partition and seg file
  //   compressionType compression type
  void writeDictionaryStoreMetaData(OID columnOID, OID dictionaryStoreOID, uint16_t dbRoot,
                                    uint32_t partition, uint16_t segment, HWM localHwm, int compressionType);

  // For first extent stripe in a partition, this function is used to
  // to log a marker to denote a trailing segment file that does not exist.
  // This is the Shared-Nothing version of this function.
  //   dictionaryStoreOID dictionary store OID to be saved
  //   dbRoot dbRoot of store file
  //   partition partition of store file
  //   segment segment of store file
  //   compressionType compression type
  void writeDictionaryStoreMetaNoDataMarker(OID columnOID, OID dictionaryStoreOID, uint16_t dbRoot,
                                            uint32_t partition, uint16_t segment, int compressionType);

  // This function must be thread-safe since it is called indirectly by
  // backupDctnryHWMChunk() (through backupHWMChunk()).
  int writeHWMChunk(bool bColumnFile, OID columnOID, uint16_t dbRoot, uint32_t partition, uint16_t segment,
                    const unsigned char* compressedOutBuf, uint64_t chunkSize, uint64_t fileSize,
                    HWM chunkHwm, std::string& errMsg) const;
  void printDctnryChunkList(const RBChunkInfo& rbChk, const char* action);

  IDBDataFile* fMetaDataFile;                      // current meta data file to write
  std::ostringstream fMetaDataStream;              // adapter for IDBDataFile
  std::map<uint16_t, std::string> fMetaFileNames;  // map of dbroots to metafiles
  std::string fAppDesc;                            // description of application user
  Log* fLog;                                       // import log file
  bool fCreatedSubDir;                             // has subdir path been created
  RBChunkSet fRBChunkDctnrySet;                    // Dctnry HWM chunk info
  boost::mutex fRBChunkDctnryMutex;                // Mutex lock for RBChunkSet
  OID fTableOID;                                   // OID of relevant table
  std::string fTableName;                          // Name of relevant table
};

}  // namespace WriteEngine

#undef EXPORT