dblqh.hpp

mysql-5.0.22.tar.gz源码包

   *      request to TUP or ACC. Used for both local checkpoints and
   *      system restart.
   */
  struct LcpLocRecord {
    enum LcpLocstate {
      IDLE = 0,
      WAIT_TUP_PREPLCP = 1,
      WAIT_LCPHOLDOP = 2,
      HOLDOP_READY = 3,
      ACC_WAIT_STARTED = 4,
      ACC_STARTED = 5,
      ACC_COMPLETED = 6,
      TUP_WAIT_STARTED = 7,
      TUP_STARTED = 8,
      TUP_COMPLETED = 9,
      SR_ACC_STARTED = 10,
      SR_TUP_STARTED = 11,
      SR_ACC_COMPLETED = 12,
      SR_TUP_COMPLETED = 13
    };
    enum WaitingBlock {
      ACC = 0,
      TUP = 1,
      NONE = 2
    };
    
    LcpLocstate lcpLocstate;
    UintR locFragid;
    UintR masterLcpRec;
    UintR nextLcpLoc;
    UintR tupRef;
    WaitingBlock waitingBlock;
    Uint32 accContCounter;
  }; // 28 bytes
  typedef Ptr<LcpLocRecord> LcpLocRecordPtr;
  
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /*                                                                          */
  /*       THE RECORDS THAT START BY LOG_ ARE A PART OF THE LOG MANAGER.      */
  /*       THESE RECORDS ARE USED TO HANDLE THE FRAGMENT LOG.                 */
  /*                                                                          */
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /* $$$$$$$                       LOG RECORD                         $$$$$$$ */
  /*                                                                          */
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /*       THIS RECORD IS ALIGNED TO BE 256 BYTES.                            */
  /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */
  /**       
   *       This record describes the current state of a log. 
   *       A log consists of a number of log files. 
   *       These log files are described by the log file record.
   *
   *       There will be 4 sets of log files. 
   *       Different tables will use different log files dependent 
   *       on the table id. 
   *       This  ensures that more than one outstanding request can 
   *       be sent to the file system.
   *       The log file to use is found by performing a very simple hash
   *       function.
   */
  struct LogPartRecord {
    enum LogPartState {
      IDLE = 0,                       ///< Nothing happens at the moment
      ACTIVE = 1,                     ///< An operation is active logging 
      SR_FIRST_PHASE = 2,             ///< Finding the end of the log and 
                                      ///< the information about global 
                                      ///< checkpoints in the log is ongoing.
      SR_FIRST_PHASE_COMPLETED = 3,   ///< First phase completed
      SR_THIRD_PHASE_STARTED = 4,     ///< Executing fragment log is in 3rd ph
      SR_THIRD_PHASE_COMPLETED = 5,
      SR_FOURTH_PHASE_STARTED = 6,    ///< Finding the log tail and head 
                                      ///< is the fourth phase.
      SR_FOURTH_PHASE_COMPLETED = 7,
      FILE_CHANGE_PROBLEM = 8,        ///< For some reason the write to 
                                      ///< page zero in file zero have not   
                                      ///< finished after 15 mbyte of 
                                      ///< log data have been written
      TAIL_PROBLEM = 9                ///< Only 1 mbyte of log left. 
                                      ///< No operations allowed to enter the 
                                      ///< log. Only special log records 
                                      ///< are allowed
    };
    enum WaitWriteGciLog {
      WWGL_TRUE = 0,
      WWGL_FALSE = 1
    };
    enum LogExecState {
      LES_IDLE = 0,
      LES_SEARCH_STOP = 1,
      LES_SEARCH_START = 2,
      LES_EXEC_LOG = 3,
      LES_EXEC_LOG_NEW_MBYTE = 4,
      LES_EXEC_LOG_NEW_FILE = 5,
      LES_EXEC_LOGREC_FROM_FILE = 6,
      LES_EXEC_LOG_COMPLETED = 7,
      LES_WAIT_READ_EXEC_SR_NEW_MBYTE = 8,
      LES_WAIT_READ_EXEC_SR = 9,
      LES_EXEC_LOG_INVALIDATE = 10
    };

    /**
     *       Is a CONTINUEB(ZLOG_LQHKEYREQ) signal sent and
     *       outstanding. We do not want several instances of this
     *       signal out in the air since that would create multiple
     *       writers of the list.
     */
    UintR LogLqhKeyReqSent;
    /**
     *       Contains the current log file where log records are
     *       written.  During system restart it is used to indicate the
     *       last log file.
     */
    UintR currentLogfile;
    /**
     *       The log file used to execute log records from far behind.
     */
    UintR execSrExecLogFile;
    /**
     *       The currently executing prepare record starts in this log
     *       page. This variable is used to enable that a log record is
     *       executed multiple times in execution of the log.
     */
    UintR execSrLogPage;
    /**
     *       This variable keeps track of the lfo record where the
     *       pages that were read from disk when an operations log
     *       record were not found in the main memory buffer for log
     *       pages.
     */
    UintR execSrLfoRec;
    /**
     *       The starting page number when reading log from far behind.
     */
    UintR execSrStartPageNo;
    /**
     *       The last page number when reading log from far behind.
     */
    UintR execSrStopPageNo;
    /**
     *       Contains a reference to the first log file, file number 0.
     */
    UintR firstLogfile;
    /**
     *       The head of the operations queued for logging.
     */
    UintR firstLogQueue;
    /** 
     *       This variable contains the oldest operation in this log
     *       part which have not been committed yet.
     */
    UintR firstLogTcrec;
    /**
     *       The first reference to a set of 8 pages. These are used
     *       during execution of the log to keep track of which pages
     *       are in memory and which are not.
     */
    UintR firstPageRef;
    /**
     *       This variable contains the global checkpoint record
     *       waiting for disk writes to complete.
     */
    UintR gcprec;
    /**
     *       The last reference to a set of 8 pages.  These are used
     *       during execution of the log to keep track of which pages
     *       are in memory and which are not.
     */
    UintR lastPageRef;
    /**
     *       The tail of the operations queued for logging.                   
     */
    UintR lastLogQueue;
    /**
     *       This variable contains the newest operation in this log
     *       part which have not been committed yet.
     */
    UintR lastLogTcrec;
    /**
     *       This variable indicates which was the last mbyte that was
     *       written before the system crashed.  Discovered during
     *       system restart.
     */
    UintR lastLogfile;
    /**
     *       This variable is used to keep track of the state during
     *       the third phase of the system restart, i.e. when
     *       LogPartRecord::logPartState == 
     *       LogPartRecord::SR_THIRD_PHASE_STARTED.
     */
    LogExecState logExecState;
    /**
     *       This variable contains the lap number of this log part.
     */
    UintR logLap;
    /**
     *       This variable contains the place to stop executing the log
     *       in this phase.
     */
    UintR logLastGci;
    /**
     *       This variable contains the place to start executing the
     *       log in this phase.
     */
    UintR logStartGci;
    /**
     *       The latest GCI completed in this log part.
     */
    UintR logPartNewestCompletedGCI;
    /**
     *       The current state of this log part.                               
     */
    LogPartState logPartState;
    /**
     *       A timer that is set every time a log page is sent to disk.
     *       Ensures that log pages are not kept in main memory for
     *       more than a certain time.
     */
    UintR logPartTimer;
    /**
     *       The current timer which is set by the periodic signal
     *       received by LQH
     */
    UintR logTimer;
    /** 
     *       Contains the number of the log tail file and the mbyte
     *       reference within that file.  This information ensures that
     *       the tail is not overwritten when writing new log records.
     */
    UintR logTailFileNo;
    /**
     *       The TcConnectionrec used during execution of this log part.
     */
    UintR logTcConrec;
    /**
     *       The number of pages that currently resides in the main
     *       memory buffer.  It does not refer pages that are currently
     *       read from the log files.  Only to pages already read
     *       from the log file.
     */
    UintR mmBufferSize;
    /**
     *       Contains the current number of log files in this log part. 
     */
    UintR noLogFiles;
    /**
     *       This variable is used only during execution of a log
     *       record.  It keeps track of in which page record a log
     *       record was started.  It is used then to deduce which
     *       pages that are dirty after that the log records on the
     *       page have been executed.
     *
     *       It is also used to find out where to write the invalidate
     *       command when that is needed.
     */
    UintR prevLogpage;
    /**
     *       The number of files remaining to gather GCI information
     *       for during system restart.  Only used if number of files
     *       is larger than 60.
     */
    UintR srRemainingFiles;
    /**
     *       The log file where to start executing the log during
     *       system restart.
     */
    UintR startLogfile;
    /**
     *       The last log file in which to execute the log during system 
     *       restart.                    
     */
    UintR stopLogfile;
    /**
     *       This variable keeps track of when we want to write a complete 
     *       gci log record but have been blocked by an ongoing log operation.
     */
    WaitWriteGciLog waitWriteGciLog;
    /**
     *       The currently executing prepare record starts in this index 
     *       in the log page.            
     */
    Uint16 execSrLogPageIndex;
    /**
     *       Which of the four exec_sr's in the fragment is currently executing
     */
    Uint16 execSrExecuteIndex;
    /**
     *       The number of pages executed in the current mbyte. 
     */
    Uint16 execSrPagesExecuted;
    /**
     *       The number of pages read from disk that have arrived and are 
     *       currently awaiting execution of the log.
     */
    Uint16 execSrPagesRead;
    /**
     *       The number of pages read from disk and currently not arrived 
     *       to the block.             
     */
    Uint16 execSrPagesReading;
    /**
     *       This variable refers to the new header file where we will 
     *       start writing the log after a system restart have been completed.
     */
    Uint16 headFileNo;
    /**
     *       This variable refers to the page number within the header file.
     */
    Uint16 headPageNo;
    /**
     *       This variable refers to the index within the new header
     *       page.
     */
    Uint16 headPageIndex;
    /**
     *       This variables indicates which was the last mbyte in the last 
     *       logfile before a system crash. Discovered during system restart.
     */
    Uint16 lastMbyte;
    /**
     *       This variable is used only during execution of a log
     *       record. It keeps track of in which file page a log
     *       record was started.  It is used if it is needed to write a
     *       dirty page to disk during log execution (this happens when
     *       commit records are invalidated).
     */
    Uint16 prevFilepage;
    /**
     *       This is used to save where we were in the execution of log
     *       records when we find a commit record that needs to be
     *       executed.
     *
     *       This variable is also used to remember the index where the
     *       log type was in the log record. It is only used in this
     *       role when finding a commit record that needs to be
     *       invalidated.
     */
    Uint16 savePageIndex;