/* * RLCDX * * Copyright 2006 Przemyslaw Czerpak * * 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, 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; see the file LICENSE.txt. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA 02110-1301 USA (or visit https://www.gnu.org/licenses/). * * As a special exception, the Harbour Project gives permission for * additional uses of the text contained in its release of Harbour. * * The exception is that, if you link the Harbour libraries with other * files to produce an executable, this does not by itself cause the * resulting executable to be covered by the GNU General Public License. * Your use of that executable is in no way restricted on account of * linking the Harbour library code into it. * * This exception does not however invalidate any other reasons why * the executable file might be covered by the GNU General Public License. * * This exception applies only to the code released by the Harbour * Project under the name Harbour. If you copy code from other * Harbour Project or Free Software Foundation releases into a copy of * Harbour, as the General Public License permits, the exception does * not apply to the code that you add in this way. To avoid misleading * anyone as to the status of such modified files, you must delete * this exception notice from them. * * If you write modifications of your own for Harbour, it is your choice * whether to permit this exception to apply to your modifications. * If you do not wish that, delete this exception notice. * */ /* * A simple RDD which introduce lock counters. It has full DBFCDX * functionality from which it inherits but if you execute dbRLock( 100 ) * twice then you will have to also repeat call to dbRUnlock( 100 ) to * really unlock the record 100. The same if for FLock() * This idea comes from one of messages sent by Mindaugas Kavaliauskas. */ #include "hbusrrdd.ch" #include "rddsys.ch" ANNOUNCE RLCDX /* * methods: NEW and RELEASE receive pointer to work area structure * not work area number. It's necessary because the can be executed * before work area is allocated * these methods does not have to execute SUPER methods - this is * always done by low-level USRRDD code */ STATIC FUNCTION RLCDX_NEW( pWA ) LOCAL aWData := { 0, {} } /* * Set in our private AREA item the array with number of FLOCKs * recursively called and array with LOCKED records */ USRRDD_AREADATA( pWA, aWData ) RETURN HB_SUCCESS STATIC FUNCTION RLCDX_LOCK( nWA, aLockInfo ) LOCAL aWData, nResult, xRecId, i aWData := USRRDD_AREADATA( nWA ) /* Convert EXCLUSIVE locks to DBLM_MULTIPLE */ IF aLockInfo[ UR_LI_METHOD ] == DBLM_EXCLUSIVE aLockInfo[ UR_LI_METHOD ] := DBLM_MULTIPLE aLockInfo[ UR_LI_RECORD ] := RecNo() ENDIF IF aLockInfo[ UR_LI_METHOD ] == DBLM_MULTIPLE /* RLOCK */ IF aWData[ 1 ] > 0 aLockInfo[ UR_LI_RESULT ] := .T. RETURN HB_SUCCESS ENDIF xRecID := aLockInfo[ UR_LI_RECORD ] IF Empty( xRecID ) xRecID := RecNo() ENDIF IF aWData[ 1 ] > 0 aLockInfo[ UR_LI_RESULT ] := .T. RETURN HB_SUCCESS ELSEIF ( i := AScan( aWData[ 2 ], {| x | x[ 1 ] == xRecID } ) ) > 0 ++aWData[ 2 ][ i ][ 2 ] aLockInfo[ UR_LI_RESULT ] := .T. RETURN HB_SUCCESS ENDIF IF ( nResult := UR_SUPER_LOCK( nWA, aLockInfo ) ) == HB_SUCCESS IF aLockInfo[ UR_LI_RESULT ] AAdd( aWData[ 2 ], { xRecID, 1 } ) ENDIF ENDIF RETURN nResult ELSEIF aLockInfo[ UR_LI_METHOD ] == DBLM_FILE /* FLOCK */ IF aWData[ 1 ] > 0 ++aWData[ 1 ] RETURN HB_SUCCESS ENDIF IF ( nResult := UR_SUPER_LOCK( nWA, aLockInfo ) ) == HB_SUCCESS /* FLOCK always first remove all RLOCKs, even if it fails */ ASize( aWData[ 2 ], 0 ) IF aLockInfo[ UR_LI_RESULT ] aWData[ 1 ] := 1 ENDIF ENDIF RETURN nResult ENDIF aLockInfo[ UR_LI_RESULT ] := .F. RETURN HB_FAILURE STATIC FUNCTION RLCDX_UNLOCK( nWA, xRecID ) LOCAL aWData := USRRDD_AREADATA( nWA ), i IF HB_ISNUMERIC( xRecID ) .AND. xRecID > 0 IF ( i := AScan( aWData[ 2 ], {| x | x[ 1 ] == xRecID } ) ) > 0 IF --aWData[ 2 ][ i ][ 2 ] > 0 RETURN HB_SUCCESS ENDIF hb_ADel( aWData[ 2 ], i, .T. ) ELSE RETURN HB_SUCCESS ENDIF ELSE IF aWData[ 1 ] > 1 --aWData[ 1 ] RETURN HB_SUCCESS ENDIF aWData[ 1 ] := 0 ASize( aWData[ 2 ], 0 ) ENDIF RETURN UR_SUPER_UNLOCK( nWA, xRecID ) STATIC FUNCTION RLCDX_APPEND( nWA, lUnlockAll ) LOCAL aWData, nResult, xRecId, i /* Never unlock other records, they have to be explicitly unlocked */ lUnlockAll := .F. IF ( nResult := UR_SUPER_APPEND( nWA, lUnlockAll ) ) == HB_SUCCESS aWData := USRRDD_AREADATA( nWA ) IF aWData[ 1 ] == 0 xRecId := RecNo() /* Some RDDs may allow to set phantom locks with RLOCK so we should check if it's not the case and increase the counter when it is */ IF ( i := AScan( aWData[ 2 ], {| x | x[ 1 ] == xRecID } ) ) > 0 ++aWData[ 2 ][ i ][ 2 ] ELSE AAdd( aWData[ 2 ], { xRecID, 1 } ) ENDIF ENDIF ENDIF RETURN nResult /* Force linking DBFCDX from which our RDD inherits */ REQUEST DBFCDX /* * This function have to exist in all RDD and then name have to be in * format: _GETFUNCTABLE */ FUNCTION RLCDX_GETFUNCTABLE( pFuncCount, pFuncTable, pSuperTable, nRddID, pSuperRddID ) LOCAL cSuperRDD := "DBFCDX" /* We are inheriting from DBFCDX */ LOCAL aMethods[ UR_METHODCOUNT ] aMethods[ UR_NEW ] := @RLCDX_NEW() aMethods[ UR_LOCK ] := @RLCDX_LOCK() aMethods[ UR_UNLOCK ] := @RLCDX_UNLOCK() aMethods[ UR_APPEND ] := @RLCDX_APPEND() RETURN USRRDD_GETFUNCTABLE( pFuncCount, pFuncTable, pSuperTable, nRddID, ; cSuperRDD, aMethods, pSuperRddID ) INIT PROCEDURE RLCDX_INIT() rddRegister( "RLCDX", RDT_FULL ) RETURN