~drizzle-trunk/drizzle/development

/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2011 David Shrewsbury

 *

 *  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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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

 */

#pragma once

#include <plugin/slave/queue_thread.h>

#include <plugin/slave/sql_executor.h>

#include <drizzled/session.h>

#include <string>

namespace drizzled

{

  namespace message

  {

    class Transaction;

  }

}

namespace slave

{

class QueueConsumer : public QueueThread, public SQLExecutor

{

public:

  QueueConsumer() :

    QueueThread(),

    SQLExecutor("slave", "replication"),

    _check_interval(5),

    _ignore_errors(false)

  { }

  bool init();

  bool process();

  void shutdown();

  void setSleepInterval(uint32_t seconds)

  {

    _check_interval= seconds;

  }

  uint32_t getSleepInterval()

  {

    return _check_interval;

  }

  /**

   * Determines if we should ignore errors from statements pulled from masters.

   */

  void setIgnoreErrors(bool value)

  {

    _ignore_errors= value;

  }

  /**

   * Update applier status in state table.

   *

   * @param err_msg Error message string

   * @param status false = STOPPED, true = RUNNING

   */

  void setApplierState(const std::string &err_msg, bool status);

  void addMasterId(uint32_t id)

  {

    _master_ids.push_back(id);

  }

  bool processSingleMaster(const std::string &master_id);

private:

  typedef std::vector<uint64_t> TrxIdList;

  /** Number of seconds to sleep between checking queue for messages */

  uint32_t _check_interval;

  std::vector<uint32_t> _master_ids;

  bool _ignore_errors;

  /**

   * Get a list of transaction IDs from the queue that are complete.

   *

   * A "complete" transaction is one in which we have received the end

   * segment of the transaction.

   *

   * @param[in] master_id Identifier of the master we are interested in.

   * @param[out] list The list to populate with transaction IDs.

   *

   * @retval true Success

   * @retval false Error

   */

  bool getListOfCompletedTransactions(const std::string &master_id,

                                      TrxIdList &list);

  bool getMessage(drizzled::message::Transaction &transaction,

                  std::string &commit_id,

                  const std::string &master_id,

                  uint64_t trx_id,

                  std::string &originating_server_uuid,

                  uint64_t &originating_commit_id,

                  uint32_t segment_id);

  /**

   * Convert the given Transaction message into equivalent SQL.

   *

   * @param[in] transaction Transaction protobuf message to convert.

   * @param[in,out] aggregate_sql Buffer for total SQL for this transaction.

   * @param[in,out] segmented_sql Buffer for carried over segmented statements.

   *

   * @retval true Success

   * @retval false Failure

   */

  bool convertToSQL(const drizzled::message::Transaction &transaction,

                    std::vector<std::string> &aggregate_sql,

                    std::vector<std::string> &segmented_sql);

  /**

   * Execute a batch of SQL statements.

   *

   * @param sql Batch of SQL statements to execute.

   * @param commit_id Commit ID value to store in state table.

   * @param originating_server_uuid Server ID of the master where

   *   this SQL was originally applied.

   * @param originating_commit_id Commit ID of the master where

   *   this SQL was originally applied.

   *

   * @retval true Success

   * @retval false Failure

   */

  bool executeSQLWithCommitId(std::vector<std::string> &sql,

                              const std::string &commit_id,

                              const std::string &originating_server_uuid,

                              uint64_t originating_commit_id,

                              const std::string &master_id);

  /**

   * Remove messages for a given transaction from the queue.

   *

   * @param trx_id Transaction ID for the messages to remove.

   *

   * @retval true Success

   * @retval false Failure

   */

  bool deleteFromQueue(const std::string &master_id, uint64_t trx_id);

  /**

   * Determine if a Statement message is an end message.

   *

   * @retval true Is an end Statement message

   * @retval false Is NOT an end Statement message

   */

  bool isEndStatement(const drizzled::message::Statement &statement);

};

} /* namespace slave */