// Use TableUpd.nui // Class for updating table data

use dfallent
Use Base.nui     // Item_Property command, Various macros (FOR_EX...), cArray, cSet and cStack classes (No User Interface)
Use Spec0008.utl // Small arrays with integer Codes (Dictionaries)
Use DBMS.nui     // Basic DBMS functions (No User Interface)
Use ErrorHnd.nui // cErrorHandlerRedirector class and oErrorHandlerQuiet object (No User Interface)
Use API_Attr.nui // Functions for querying API attributes (No User Interface)
Use ApiIndex.nui // Switch indices offline and online

desktop_section
  object oTableUpdateLockModes is a cIntegerCodeToText
    IntegerCodeList
      Define_IntegerCode TUPD_LOCK_MODE_OPEN_EXCLUSIVE   "Lock mode"
      Define_IntegerCode TUPD_LOCK_MODE_ONE_TRANSACTION  "All in one transaction"
      Define_IntegerCode TUPD_LOCK_MODE_UNLOCK_EVERY     "Transaction size"
      Define_IntegerCode TUPD_LOCK_MODE_NO_LOCK          "No locking"
    End_IntegerCodeList
  end_object

  object oTableUpdateParameterList is a cIntegerCodeToText
    IntegerCodeList
      Define_IntegerCode TUPD_CREATE_NEW_TABLE     "Create new table"
      Define_IntegerCode TUPD_ZEROFILE_TABLE       "Reset table before reading"
      Define_IntegerCode TUPD_OVERWRITE_EXISTING   "Overwrite existing data"
      Define_IntegerCode TUPD_DO_NOT_CHECK_INDEX   "Do not check for existing records"
      Define_IntegerCode TUPD_SWITCH_INDEX_OFFLINE "Switch indices off-line"
      Define_IntegerCode TUPD_LOCK_MODE            "Lock mode"
      Define_IntegerCode TUPD_UNLOCK_COUNT         "Unlock every # record"
    End_IntegerCodeList
  end_object
end_desktop_section

class cTableUpdateParameters is a cArray
  procedure construct_object integer liImage
    forward send construct_object liImage
    set value item TUPD_CREATE_NEW_TABLE     to DFFALSE
    set value item TUPD_ZEROFILE_TABLE       to DFFALSE
    set value item TUPD_OVERWRITE_EXISTING   to DFFALSE
    set value item TUPD_DO_NOT_CHECK_INDEX   to DFFALSE
    set value item TUPD_SWITCH_INDEX_OFFLINE to DFFALSE
    set value item TUPD_LOCK_MODE            to TUPD_LOCK_MODE_UNLOCK_EVERY
    // Transaction chunk size. Setting TUPD_LOCK_MODE to
    // TUPD_LOCK_MODE_UNLOCK_EVERY and TUPD_UNLOCK_COUNT to 1
    // will make the cTableUpdater respond to every lock request.
    // Setting it to 500 will make the cTable updater unlock
    // for every 500 update
    set value item TUPD_UNLOCK_COUNT         to 500
  end_procedure
end_class // cTableUpdateParameters

desktop_section // Return values for iBeginTransaction function
  object oTableUpdateLockRtnVal is a cIntegerCodeToText
    IntegerCodeList
      Define_IntegerCode TUPD_ILOCK_RTN_OK                   "OK"
      Define_IntegerCode TUPD_ILOCK_RTN_MISSING_PARAM_OBJECT "Control object not found"
      Define_IntegerCode TUPD_ILOCK_RTN_TABLE_COULDNT_OPEN   "Table could not be opened"
    End_IntegerCodeList
  end_object
end_desktop_section

class cTableUpdater is a cArray

  procedure construct_object integer liImage
    forward send construct_object liImage
    property integer phTableUpdateParameters public 0
    property integer piFile                  public 0
    // The name of the table including path. If the table should be opened
    // via FileList only, this property should be left empty.
    property string  psFilePathName          public ""
    property integer piRequestSaveCount      public 0
    property integer piErrorCount            public 0
    property integer piLockRequestCount      public 0

    // This property holds the transaction chunk size from the setup object
    // once the transaction is started.
    property integer piPrv.LockResponse      public 0
    property integer piPrv.LockMode          public 0

    property string  psPrv.Indices           public ""
  end_procedure

            // If file <liFile> is already open when this function os called
            // no attempt is made to interpret the contents of property
            // psFilePathName. In that case the file will remain open in its
            // current mode.
            function iOpen returns integer
              local integer liLockMode liRval liFile liOpenMode liOpenRes
              local string lsFilePathName

              move TUPD_ILOCK_RTN_OK to liRval // No errors, default return value

              get piFile         to liFile
              get psFilePathName to lsFilePathName
              get value of (phTableUpdateParameters(self)) item TUPD_LOCK_MODE to liLockMode
              // If the file is not already open:
              ifnot (integer(API_AttrValue_FILE(DF_FILE_OPENED,liFile))) begin
                if (liLockMode=TUPD_LOCK_MODE_OPEN_EXCLUSIVE) move DF_EXCLUSIVE to liOpenMode
                else move DF_SHARE to liOpenMode
                if (lsFilePathName="") move (DBMS_OpenFile(liFile,liOpenMode,0)) to liOpenRes
                else move (DBMS_OpenFileAs(lsFilePathName,liFile,liOpenMode,0)) to liOpenRes
                ifnot liOpenRes move TUPD_ILOCK_RTN_TABLE_COULDNT_OPEN to liRval
              end
              set piLockRequestCount to 0
              set piRequestSaveCount to 0
              set piErrorCount       to 0
              set piPrv.LockResponse to (value(phTableUpdateParameters(self),TUPD_UNLOCK_COUNT))
              set piPrv.LockMode     to (value(phTableUpdateParameters(self),TUPD_LOCK_MODE))
              function_return liRval
            end_function

            procedure SwitchIndicesOffLine
              local integer liFile
              local string lsIndices
              get piFile to liFile
              get DoSwitchIndicesOffLine liFile to lsIndices
              set psPrv.Indices to lsIndices
            end_procedure
            procedure SwitchIndicesOnLine
              local integer liFile
              local string lsIndices
              get piFile to liFile
              get psPrv.Indices to lsIndices
              send DoSwitchIndicesOnline liFile lsIndices
            end_procedure

  function iBeginTransaction returns integer
    local integer lhTableUpdateParameters liRval liLockMode lbZerofile liFile
    local integer IbIndicesOffline
    get piFile to liFile
    get phTableUpdateParameters to lhTableUpdateParameters
    if lhTableUpdateParameters begin
      get iOpen to liRval
      if (liRval=TUPD_ILOCK_RTN_OK) begin // It opened OK
        get value of lhTableUpdateParameters item TUPD_ZEROFILE_TABLE to lbZerofile
        if lbZerofile zerofile liFile

        get value of lhTableUpdateParameters item TUPD_SWITCH_INDEX_OFFLINE to IbIndicesOffline
        if IbIndicesOffline send SwitchIndicesOffLine

        // If it has been specified that all should be done in one
        // transaction, we lock the file here:
        get value of lhTableUpdateParameters item TUPD_LOCK_MODE to liLockMode
        if liLockMode eq TUPD_LOCK_MODE_ONE_TRANSACTION lock
      end
    end
    else move TUPD_ILOCK_RTN_MISSING_PARAM_OBJECT to liRval
    function_return liRval
  end_function

  function iEndTransaction returns integer
    local integer liLockMode IbIndicesOffline lhTableUpdateParameters
    get phTableUpdateParameters to lhTableUpdateParameters
    get piPrv.LockMode to liLockMode
    if (liLockMode=TUPD_LOCK_MODE_ONE_TRANSACTION) unlock
    if (liLockMode=TUPD_LOCK_MODE_UNLOCK_EVERY and piLockRequestCount(self)<>0) unlock

    get value of lhTableUpdateParameters item TUPD_SWITCH_INDEX_OFFLINE to IbIndicesOffline
    if IbIndicesOffline send SwitchIndicesOnLine

    function_return 0 // All is well
  end_function

  procedure DoLock
    local integer liLockRequestCount
    // We lock only if lock mode has been set to TUPD_LOCK_MODE_UNLOCK_EVERY
    if (piPrv.LockMode(self)=TUPD_LOCK_MODE_UNLOCK_EVERY) begin
      get piLockRequestCount to liLockRequestCount
      ifnot liLockRequestCount lock
      set piLockRequestCount to (liLockRequestCount+1)
    end
  end_procedure

  procedure DoUnlock
    local integer liLockRequestCount liTransactionChunkSize
    get piLockRequestCount to liLockRequestCount
    get piPrv.LockResponse to liTransactionChunkSize
    if (liLockRequestCount>=liTransactionChunkSize) begin
      unlock
      set piLockRequestCount to 0
    end
  end_procedure

  // The function returns the number of errors generated by the
  // saverecord command.
  function iSaveRecord returns integer
    local integer liFile liRval
    get piFile to liFile
    set piRequestSaveCount to (piRequestSaveCount(self)+1)
//  send ErrorHnd_Quiet_Activate // Transfer error handling to quiet handler
    saverecord liFile
//  send ErrorHnd_Quiet_Deactivate // Reset to normal error handling
//  move (ErrorHnd_Quiet_ErrorCount()) to liRval
    if liRval set piErrorCount to (piErrorCount(self)+1)
    function_return liRval
  end_function
end_class