mars-flaim/flaim/src/fsrefupd.cpp

//-------------------------------------------------------------------------
// Desc:	Index reference updating.
// Tabs:	3
//
//		Copyright (c) 1991-2006 Novell, Inc. All Rights Reserved.
//
//		This program is free software; you can redistribute it and/or
//		modify it under the terms of version 2 of the GNU General Public
//		License as published by the Free Software Foundation.
//
//		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, contact Novell, Inc.
//
//		To contact Novell about this file by physical or electronic mail,
//		you may find current contact information at www.novell.com
//
// $Id: fsrefupd.cpp 12321 2006-01-19 15:55:00 -0700 (Thu, 19 Jan 2006) dsanders $
//-------------------------------------------------------------------------

#include "flaimsys.h"

/* #define	REF_TESTING - set for quick testing */

#define	INSERT_REF		0
#define	DELETE_REF		1
#define	SPLIT_90_10		0
#define	SPLIT_50_50		1

/**--------------------
***  Static routines
***-------------------*/

FSTATIC RCODE FSUpdateIxCounts(
	FDB *		pDb,
	IXD *		pIxd,
	FLMBYTE	byFlags,
	FLMBOOL	bSingleRef);

FSTATIC RCODE FSOutputIxCounts(
	FDB *			pDb,
	IX_STATS *	pIxStats);

FSTATIC RCODE FSRefCreateRec(
	FDB *				pDb,
	LFILE *			pLFile,
	KREF_ENTRY_p	pKrefEntry,
	BTSK_p 			pStack);

FSTATIC RCODE FSRefInsert(
	FDB *				pDb,
	LFILE *			pLFile,
	KREF_ENTRY_p	pKrefEntry,
	BTSK_p 			pStack);

FSTATIC RCODE FSRefDelete(
	FDB *				pDb,
	LFILE *			pLFile,
	KREF_ENTRY_p	pKrefEntry,
	BTSK_p 			pStack,
	FLMBOOL *		pbSingleRef);


// Defined in fsnext.cpp
extern FLMBYTE	SENLenArray[];

/***************************************************************************
Desc:		Update (add or delete) a single reference
TODO:		Index by the logical file attribute to determine the compression
			method of the index.	Try multipling by index compression type.
*****************************************************************************/
RCODE FSRefUpdate(
	FDB *				pDb,
	LFILE *			pLFile,
	KREF_ENTRY_p	pKrefEntry
	)
{
	RCODE				rc;
	BTSK				stackBuf[ BH_MAX_LEVELS ];	// Stack to hold b-tree variables
	BTSK_p			pStack = stackBuf;			// Points to proper stack frame
	FLMUINT			uiDinDomain = DIN_DOMAIN( pKrefEntry->uiDrn) + 1; // Lower bounds
	FLMBYTE			byFlags = (FLMBYTE)pKrefEntry->uiFlags;
	FLMBOOL			bSingleRef = FALSE;
	FLMBOOL			bAddReference = (byFlags & KREF_DELETE_FLAG) ? FALSE : TRUE;
	FLMBYTE			pKeyBuf[ MAX_KEY_SIZ ];		// Key buffer pointed to by stack

FSRU_try_again:
	
	if (pKrefEntry->uiFlags & KREF_ENCRYPTED_KEY)
	{
		// Can't allow updates whit these keys.
		flmAssert( pDb->pFile->bInLimitedMode);
		rc = RC_SET( FERR_ENCRYPTION_UNAVAILABLE);
		goto Exit;
	}
	
	FSInitStackCache( &stackBuf [0], BH_MAX_LEVELS);
	pStack = stackBuf;
	pStack->pKeyBuf = pKeyBuf;

	if( RC_BAD( rc = FSBtSearch( pDb, pLFile, &pStack,
			(FLMBYTE *) &pKrefEntry[1], pKrefEntry->ui16KeyLen, uiDinDomain)))
	{
		// GWBUG 57352: July 17, 1998.  Had a return() here that would
		// keep block use count on block.
		goto Exit;
	}

	// If pStack->bsStatus == REC_NOT_FOUND create a new element
	// if found then add the reference into the found element.

	if( pStack->uiCmpStatus == BT_EQ_KEY)
	{
		if( (byFlags & KREF_UNIQUE_KEY) && !(byFlags & KREF_DELETE_FLAG))
		{
			rc = RC_SET( FERR_NOT_UNIQUE);
			goto Exit;
		}

		if( pLFile->pIxd->uiFlags & IXD_POSITIONING)
		{
			if ( RC_BAD( rc = FSChangeCount( pDb, pStack, bAddReference)))
			{
				goto Exit;
			}
		}

		bSingleRef = FALSE;

		if( bAddReference)
		{
			if( RC_BAD( rc = FSRefInsert( pDb, pLFile, pKrefEntry, pStack)))
				goto Exit;
		}
		else
		{
			if( RC_BAD( rc = FSRefDelete( pDb, pLFile, 
									pKrefEntry, pStack, &bSingleRef)))
			{
				goto Exit;
			}
		}
	}
	else
	{
		if( !bAddReference)
		{
			// Already been deleted, ignore the error condition and go on.
			flmAssert( 0);
			rc = FERR_OK;
			goto Exit;
		}

		// The B-Tree may be empty

		if( pLFile->uiRootBlk == BT_END)
		{
			if( RC_BAD( rc = flmLFileInit( pDb, pLFile)))
			{
				goto Exit;
			}

			FSReleaseStackCache( stackBuf, BH_MAX_LEVELS, FALSE);
			goto FSRU_try_again;
		}

		if( pLFile->pIxd->uiFlags & IXD_POSITIONING)
		{
			if ( RC_BAD( rc = FSChangeCount( pDb, pStack, TRUE)))
			{
				goto Exit;
			}
		}

		// Add new key|reference element.
		
		bSingleRef = TRUE;
		if( RC_BAD( rc = FSRefCreateRec( pDb, pLFile, pKrefEntry, pStack )))
		{
			goto Exit;
		}
	}

Exit:

	FSReleaseStackCache( stackBuf, BH_MAX_LEVELS, FALSE);
	if (RC_OK( rc) && (pLFile->pIxd->uiFlags & IXD_COUNT))
	{
		rc = FSUpdateIxCounts( pDb, pLFile->pIxd, byFlags, bSingleRef);
	}
	return( rc );
}

/***************************************************************************
Desc:	Update the index reference and/or key counts in memory only.  Counts
		are not written to the database until transaction commit time.
*****************************************************************************/
FSTATIC RCODE FSUpdateIxCounts(
	FDB *		pDb,
	IXD *		pIxd,
	FLMBYTE	byFlags,
	FLMBOOL	bSingleRef
	)
{
	RCODE			rc = FERR_OK;
	IX_STATS *	pIxStat;

	// See if we have already created an IX_STATS structure in memory

	pIxStat = pDb->pIxStats;
	while (pIxStat && pIxStat->uiIndexNum != pIxd->uiIndexNum)
	{
		pIxStat = pIxStat->pNext;
	}

	// Allocate an IX_STATS if we didn't find one.

	if (!pIxStat)
	{
		if (RC_BAD( rc = f_calloc( sizeof( IX_STATS), &pIxStat)))
		{
			goto Exit;
		}
		pIxStat->uiIndexNum = pIxd->uiIndexNum;
		pIxStat->pNext = pDb->pIxStats;
		pDb->pIxStats = pIxStat;
	}

	// Determine whether to increment or decrement the counts

	if (byFlags & KREF_DELETE_FLAG)
	{
		if (bSingleRef)
		{
			pIxStat->iDeltaKeys--;
		}
		pIxStat->iDeltaRefs--;
	}
	else
	{
		if (bSingleRef)
		{
			pIxStat->iDeltaKeys++;
		}
		pIxStat->iDeltaRefs++;
	}
Exit:
	return( rc);
}

/***************************************************************************
Desc:	Output the index reference and/or key counts by writing them to
		the tracker record.
*****************************************************************************/
FSTATIC RCODE FSOutputIxCounts(
	FDB *			pDb,
	IX_STATS *	pIxStats
	)
{
	RCODE			rc = FERR_OK;
	FLMBOOL		bCreateRec;
	FlmRecord * pRecord = NULL;
	FlmRecord *	pTmpRec = NULL;
	void *		pvField;
	FLMUINT		uiCount;
	LFILE *		pLFile;

	// If no counts changed, do nothing

	if (!pIxStats->iDeltaKeys && !pIxStats->iDeltaRefs)
	{
		goto Exit;
	}

	if (RC_BAD( rc = fdictGetContainer( pDb->pDict,
							FLM_TRACKER_CONTAINER, &pLFile)))
	{
		goto Exit;
	}

	// Retrieve the tracker record from record cache.

	if (RC_BAD( rc = flmRcaRetrieveRec( pDb, NULL, FLM_TRACKER_CONTAINER,
			pIxStats->uiIndexNum, TRUE, NULL, NULL, &pRecord)))
	{
		if (rc != FERR_NOT_FOUND)
		{
			goto Exit;
		}
		bCreateRec = TRUE;
		rc = FERR_OK;
	}
	else
	{
		bCreateRec = FALSE;
	}

	// If there was no record, create one.  Otherwise, copy the record

	if (bCreateRec)
	{
		if( (pTmpRec = f_new FlmRecord) == NULL)
		{
			rc = RC_SET( FERR_MEM);
			goto Exit;
		}

		// Create at least the root node.

		if (RC_BAD( rc = pTmpRec->insertLast( 0, FLM_INDEX_TAG,
									FLM_CONTEXT_TYPE, &pvField)))
		{
			goto Exit;
		}
	}
	else
	{
		if ((pTmpRec = pRecord->copy()) == NULL)
		{
			rc = RC_SET( FERR_MEM);
			goto Exit;
		}
	}

	// Update the key count.

	if (pIxStats->iDeltaKeys)
	{
		if ((pvField = pTmpRec->find( pTmpRec->root(), FLM_KEY_TAG)) == NULL)
		{

			// Cannot make key count negative.

			if (pIxStats->iDeltaKeys < 0)
			{
				flmAssert( 0);
				pIxStats->iDeltaKeys = 0;
			}
			if (RC_BAD( rc = pTmpRec->insert( pTmpRec->root(), INSERT_LAST_CHILD,
										FLM_KEY_TAG, FLM_NUMBER_TYPE, &pvField)))
			{
				goto Exit;
			}
			uiCount = (FLMUINT)pIxStats->iDeltaKeys;
		}
		else
		{
			if (RC_BAD( rc = pTmpRec->getUINT( pvField, &uiCount)))
			{
				goto Exit;
			}

			if (pIxStats->iDeltaKeys < 0)
			{
				pIxStats->iDeltaKeys = -pIxStats->iDeltaKeys;

				if ((FLMUINT)pIxStats->iDeltaKeys <= uiCount)
				{
					uiCount -= (FLMUINT)pIxStats->iDeltaKeys;
				}
				else
				{

					// Key count cannot go negative.

					flmAssert( 0);
					uiCount = 0;
				}
			}
			else
			{
				uiCount += (FLMUINT)pIxStats->iDeltaKeys;
			}
		}
		if (RC_BAD( rc = pTmpRec->setUINT( pvField, uiCount)))
		{
			goto Exit;
		}
	}

	// Update the references count

	if (pIxStats->iDeltaRefs)
	{
		if ((pvField = pTmpRec->find( pTmpRec->root(), FLM_REFS_TAG)) == NULL)
		{

			// Cannot make reference count negative.

			if (pIxStats->iDeltaRefs < 0)
			{
				flmAssert( 0);
				pIxStats->iDeltaRefs = 0;
			}
			if (RC_BAD( rc = pTmpRec->insert( pTmpRec->root(), INSERT_LAST_CHILD,
										FLM_REFS_TAG, FLM_NUMBER_TYPE, &pvField)))
			{
				goto Exit;
			}
			uiCount = (FLMUINT)pIxStats->iDeltaRefs;
		}
		else
		{
			if (RC_BAD( rc = pTmpRec->getUINT( pvField, &uiCount)))
			{
				goto Exit;
			}

			if (pIxStats->iDeltaRefs < 0)
			{
				pIxStats->iDeltaRefs = -pIxStats->iDeltaRefs;

				if ((FLMUINT)pIxStats->iDeltaRefs <= uiCount)
				{
					uiCount -= (FLMUINT)pIxStats->iDeltaRefs;
				}
				else
				{

					// Reference count cannot go negative.

					flmAssert( 0);
					uiCount = 0;
				}
			}
			else
			{
				uiCount += (FLMUINT)pIxStats->iDeltaRefs;
			}
		}
		if (RC_BAD( rc = pTmpRec->setUINT( pvField, uiCount)))
		{
			goto Exit;
		}
	}

	// Update or add the record.

	pTmpRec->setID( pIxStats->uiIndexNum);
	pTmpRec->setContainerID( FLM_TRACKER_CONTAINER);

	if (bCreateRec)
	{
		if (RC_BAD( rc = FSRecUpdate( pDb, pLFile, pTmpRec,
							pIxStats->uiIndexNum, REC_UPD_ADD)))
		{
			goto Exit;
		}

		// Put the record into record cache.

		if( RC_BAD( rc = flmRcaInsertRec( pDb, pLFile, pIxStats->uiIndexNum,
										pTmpRec)))
		{

			// Remove the record that was added.

			(void)FSRecUpdate( pDb, pLFile, NULL, pIxStats->uiIndexNum,
							REC_UPD_DELETE);
			goto Exit;
		}
	}
	else
	{

		// Modify the record.

		if (RC_BAD( rc = FSRecUpdate( pDb, pLFile, pTmpRec,
					pIxStats->uiIndexNum, REC_UPD_MODIFY)))
		{
			goto Exit;
		}

		// Put the modified record into record cache.

		if (RC_BAD( rc = flmRcaInsertRec( pDb, pLFile,
									pIxStats->uiIndexNum, pTmpRec)))
		{

			// Undo the record that was modified - replace with original record.

			(void)FSRecUpdate( pDb, pLFile, pRecord,
								pIxStats->uiIndexNum, REC_UPD_MODIFY);
			goto Exit;
		}
	}

Exit:

	if (pRecord)
	{
		pRecord->Release();
	}

	if (pTmpRec)
	{
		pTmpRec->Release();
	}
	return( rc );
}

/***************************************************************************
Desc:	Free the index stats structures for an FDB.
*****************************************************************************/
void FSFreeIxCounts(
	FDB *	pDb
	)
{
	IX_STATS *	pNextIxStat;

	while (pDb->pIxStats)
	{
		pNextIxStat = pDb->pIxStats->pNext;
		f_free( &pDb->pIxStats);
		pDb->pIxStats = pNextIxStat;
	}
}

/***************************************************************************
Desc:	Commit the index reference and/or key counts for a database.  This
		routine is only called at commit time.
*****************************************************************************/
RCODE FSCommitIxCounts(
	FDB *	pDb)
{
	RCODE			rc = FERR_OK;
	IX_STATS *	pNextIxStat;

	while (pDb->pIxStats)
	{
		pNextIxStat = pDb->pIxStats->pNext;
		if (RC_BAD( rc = FSOutputIxCounts( pDb, pDb->pIxStats)))
		{
			goto Exit;
		}
		f_free( &pDb->pIxStats);
		pDb->pIxStats = pNextIxStat;
	}
Exit:

	if (RC_BAD( rc))
	{
		FSFreeIxCounts( pDb);
	}

	return( rc);
}

/***************************************************************************
Desc:		Create a new record and add the reference to it.
Notes:	The record size is the size of the only SEN value
			There is no overhead for references for the entry compression
*****************************************************************************/
FSTATIC RCODE FSRefCreateRec(
	FDB *				pDb,
	LFILE *			pLFile,
	KREF_ENTRY_p	pKrefEntry,
	BTSK_p 			pStack)
{
	RCODE			rc;
	FLMUINT		uiElmSize;					// Element size for insert
	FLMUINT		uiKeyLen = pKrefEntry->ui16KeyLen;
	FLMUINT		uiRecLen;
	FLMBYTE *	pSen;
	FLMBYTE		byElmBuf[ MAX_KEY_SIZ + BBE_KEY + SEN_MAX_SIZ ];

	// Create the element overhead 

	byElmBuf[ BBE_PKC ] = BBE_FIRST_FLAG | BBE_LAST_FLAG;
	BBE_SET_KL( byElmBuf, uiKeyLen );

	// Copy in the key

	f_memcpy( &byElmBuf[ BBE_KEY ], (FLMBYTE *) &pKrefEntry[1], uiKeyLen );
	uiElmSize = (BBE_KEY + uiKeyLen);

	pSen = &byElmBuf[ uiElmSize ];
	uiRecLen = SENPutNextVal( &pSen, pKrefEntry->uiDrn );
	uiElmSize += BBE_SET_RL( byElmBuf, uiRecLen );

	// Save the element

	if( RC_BAD( rc = FSBtInsert( pDb, pLFile, &pStack, byElmBuf, uiElmSize)))
	{
		goto Exit;
	}

Exit:

	return( rc);
}

/***************************************************************************
Desc:		Insert a reference into a key|reference list
Notes:	The algorithm positions for an insert and inserts the reference
			while altering the block.  If a reference split is required
			refSplit() is called and FSRefInsert() could be recursively called.
*****************************************************************************/
FSTATIC RCODE FSRefInsert(
	FDB *			pDb,
	LFILE *		pLFile,
	KREF_ENTRY_p pKrefEntry,
	BTSK_p 		pStack)
{
	RCODE			rc;
	FLMBYTE *	pElement = CURRENT_ELM( pStack );	// Points to element
	FLMUINT		uiElmLen = (FLMUINT) BBE_GET_RL( pElement );// Length of the element
	FLMUINT		uiElmSize;									// Element size for insert
	FLMBYTE		byElmBuf[ MAX_KEY_SIZ + BBE_KEY+REF_SET_MAX_SIZ ];	// 796!

	// Build the element in byElmBuf[]
	FSSetElmOvhd( byElmBuf, BBE_KEY, 0, pStack->uiKeyLen, pElement );

	f_memcpy( &byElmBuf[ BBE_KEY ], pStack->pKeyBuf, pStack->uiKeyLen);

	if( uiElmLen > REF_SET_MAX_SIZ )
	{
		// May or may not split the reference set, but will always insert DRN
		rc = FSRefSplit( pDb, pLFile, &pStack, 
					byElmBuf,
					pKrefEntry->uiDrn,
					INSERT_REF,
					(FLMBYTE)(BBE_IS_FIRST(pElement) ? SPLIT_50_50 : SPLIT_90_10) );
	}
	else
	{
		uiElmSize = BBE_KEY + pStack->uiKeyLen;

		if( FSSetInsertRef( &byElmBuf[ uiElmSize ],
								  BBE_REC_PTR( pElement ), // Points to references
								  pKrefEntry->uiDrn,
								  &uiElmLen ))
		{
			rc = RC_SET( FERR_BTREE_ERROR);		// Entry is already there
			goto Exit;
		}
		BBE_SET_RL( byElmBuf, uiElmLen );
		rc = FSBtReplace( pDb, pLFile, &pStack, byElmBuf, uiElmSize + uiElmLen);
	}

Exit:
	return( rc );
}


/****************************************************************************
Desc:  	Insert a single reference into a reference set.  This is the code
			that supports the new DIN (Dual Integer Numbers) format for reference
			set compression.
Notes: 	This code is optimized for adding references to the front.
****************************************************************************/
RCODE FSSetInsertRef(
	FLMBYTE *		pDestRef,
	FLMBYTE *		pSrcRef,
	FLMUINT			drn,
	FLMUINT *		puiSetLength)
{
	DIN_STATE		destState, srcState;		// State info for destination & source
	FLMUINT			uiSetLength= *puiSetLength;// Source set length
	FLMUINT			uiLastDrn;					// Last drn before one tobe inserted
	FLMUINT			uiOldDelta;					// If inserting at front value=0
	FLMUINT			uiDelta;	 					// Current uiDelta value
	FLMUINT			uiNewDelta;					// Computes as uiOldDelta - uiDelta
	FLMUINT			uiOneRun;					// Value of one runs
	FLMUINT			uiPrevOneRun;				// Previous one runs value

	FLMUINT			uiLastSrcOfs;				// Last source offset
	FLMUINT			uiPrevLastSrcOfs = 0;	// Previous last source offset
	FLMUINT			uiMoveLen;					// Number of bytes to move
	FLMBYTE			byValue; 					// Temporary byte value - register

	/**
	***		Initialization Section
	**/
	uiPrevOneRun = uiOldDelta = 0;
	uiLastSrcOfs = 0;
	RESET_DINSTATE( destState );
	RESET_DINSTATE( srcState );

	// Take care of the domain value.
	if( *pSrcRef == SEN_DOMAIN)
	{
		srcState.uiOffset = 1;
		DINNextVal( pSrcRef, &srcState );
		uiLastSrcOfs = srcState.uiOffset;
	}

	uiLastDrn = DINNextVal( pSrcRef, &srcState );	// Get highest value

	if( drn > uiLastDrn)
	{
		// ADD TO THE FRONT.  Set uiDelta and uiNewDelta
		
		uiNewDelta = (uiDelta = drn) - uiLastDrn;
		goto FSSIR_add_delta;			// Move domain if there & add values.
	}

	uiOldDelta = uiLastDrn;
	uiOneRun = 0;

	// Search through the set finding where the "drn" fits in.
	while( drn < uiLastDrn)
	{
		/**
		***		Save previous last source offset & previous one runs
		**/
		uiPrevLastSrcOfs = uiLastSrcOfs;
		uiLastSrcOfs = srcState.uiOffset;
		uiPrevOneRun = uiOneRun;
		uiOneRun = 0;									// Reset each loop

		if( srcState.uiOffset >= uiSetLength)	// Check if at end
		{
			/**------------------------***
			***	APPEND TO THE END    ***
			***------------------------**/
			uiDelta = uiLastDrn - drn;				// Compute new delta value
			uiNewDelta = 0;
			goto FSSIR_add_delta;
		}
		/**
		***		Check for a run of ONE's
		**/
		byValue = pSrcRef[ srcState.uiOffset];
		if( DIN_IS_ONE_RUN( byValue ))	/* uiOneRun must be set if a 1 */
		{
			/* Read the number of one runs */
			uiOneRun = DINOneRunVal( pSrcRef, &srcState );
			uiLastDrn -= uiOneRun;
			if( drn > uiLastDrn)
				uiLastDrn = drn;						// DRN inside of one-run - duplicate!
		}
		else
		{
			uiOldDelta = DINNextVal( pSrcRef, &srcState );
			uiLastDrn -= uiOldDelta;
		}
	}	/* End while( drn < uiLastDrn) */
	
	/* Check for duplicates */
	if( drn == uiLastDrn)
		return( RC_SET( FERR_BTREE_ERROR) );	// Duplicate found or inside of one run

	uiDelta = uiLastDrn + uiOldDelta - drn;	// Compute the first delta value
	uiNewDelta = drn - uiLastDrn;					// or (uiOldDelta - uiDelta);
	
FSSIR_add_delta:

	/**-----------------------------------------------------------------***
	***		COMPRESS MULTIPLE ONE RUNS												***
	***																						***
	***	Special case if delta is 1.  Check the previous destinaion DIN	***
	***	for a 1 or a run of ones and combine to the left.					***
	***	Also check to combine a one run on the right by jumping within	***
	***	add_new_delta.																	***
	***-----------------------------------------------------------------**/

	if( uiDelta == 1 )
	{
		uiOneRun = 1;
		if( uiPrevOneRun )
		{
			f_memcpy( pDestRef, pSrcRef, destState.uiOffset = uiPrevLastSrcOfs);
			uiOneRun += uiPrevOneRun;				// Combine uiDelta and prev. one runs
		}
		else
		{
			f_memcpy( pDestRef, pSrcRef, destState.uiOffset = uiLastSrcOfs );
		}
		if( uiNewDelta == 1)
		{
			uiOneRun++;									// Combine the uiNewDelta one run
			goto FSSIR_combine_right_one_runs;
		}
		/* uiNewDelta is not 1 so write to destination and go on */
		DINPutOneRunVal( pDestRef, &destState, uiOneRun );
	}
	else
	{
		f_memcpy( pDestRef, pSrcRef, destState.uiOffset = uiLastSrcOfs );
		// No one runs found so write the delta value 
		DINPutNextVal( pDestRef, &destState, uiDelta );
	}

/*FSSIR_add_new_delta:*/
	/**
	***	Add new delta value (uiOldDelta - uiDelta)
	***	If the new delta value is == 1 then
	***	check next DIN for a 1 run and combine with the uiNewDelta run.
	***	uiNewDelta only has a value when NOT appending to the end.
	**/
	if( uiNewDelta)
	{
		if( uiNewDelta != 1)
			DINPutNextVal( pDestRef, &destState, uiNewDelta );
		else
		{
			uiOneRun = 1;
			
FSSIR_combine_right_one_runs:
			
			if( srcState.uiOffset < uiSetLength )		/* Done parsing?*/
			{
				/**
				***	CONNECT ONE RUNS
				***	Check on the right side of the source for another 1 run.
				**/
				byValue = pSrcRef[ srcState.uiOffset];
				if( DIN_IS_ONE_RUN( byValue ))
				{
					uiOneRun += DINOneRunVal( pSrcRef, &srcState );
				}
			}
			DINPutOneRunVal( pDestRef, &destState, uiOneRun );
		}
	}

/*FSSIR_move_rest_of_dins:*/

	if( (uiMoveLen = (FLMUINT)(uiSetLength - srcState.uiOffset)) != 0)
	{
		f_memcpy( &pDestRef[ destState.uiOffset ],
					 &pSrcRef[  srcState.uiOffset ], uiMoveLen );
		destState.uiOffset += uiMoveLen;
	}
	*puiSetLength = destState.uiOffset;
	return( FERR_OK );
}


/***************************************************************************
Desc:		Delete a matching reference into a key|reference list.  If this
			was the last continuation element then remove the SEN_DOMAIN value
			from the previous element.
*****************************************************************************/
FSTATIC RCODE FSRefDelete( 
	FDB *				pDb,
	LFILE *			pLFile,
	KREF_ENTRY_p	pKrefEntry,
	BTSK_p 			pStack,
	FLMBOOL *		pbSingleRef)				/* [out] return TRUE if last ref */
{
	RCODE				rc = FERR_OK;
	FLMBYTE *		pElement = CURRENT_ELM( pStack );	/* Points to element */
	FLMBYTE *		pReference;					/* Points to the references */
	FLMBYTE *		pDestRefPtr;
	FLMUINT			uiElmLen = BBE_GET_RL( pElement );	/* Length of the element */
	FLMUINT			uiElmSize;					/* Element size for insert	*/
	FLMUINT			uiSetLength;					/* Length of the new set */
	FLMUINT			uiKeyLen;
	FLMUINT			uiSenLen;
	FLMBYTE			byElmBuf[ MAX_KEY_SIZ + BBE_KEY + REF_SET_MAX_SIZ ];

	/* Build the element in byElmBuf[] */
	FSSetElmOvhd( byElmBuf, BBE_KEY, 0, pStack->uiKeyLen, pElement );

	f_memcpy( &byElmBuf[ BBE_KEY], pStack->pKeyBuf, pStack->uiKeyLen);
	pDestRefPtr = &byElmBuf[ BBE_KEY + pStack->uiKeyLen ];
	uiElmSize = (BBE_KEY + pStack->uiKeyLen);

	if( uiElmLen > REF_SET_MAX_SIZ )		/* Deletion may EXPAND element! */
	{
		/* Straight deletions MAY overflow the record portion ! ! */
		rc = FSRefSplit( pDb, pLFile, &pStack, byElmBuf, pKrefEntry->uiDrn,
								DELETE_REF, SPLIT_50_50 );
		return( rc );
	}

	pReference = BBE_REC_PTR( pElement );
	uiSetLength = uiElmLen;

	if( FSSetDeleteRef( pDestRefPtr, pReference, pKrefEntry->uiDrn, &uiSetLength ))
	{
		// 22Feb99 - before this time we returned FERR_KEY_NOT_FOUND.
		goto Exit;
	}

	BBE_SET_RL( byElmBuf, uiSetLength );
	/* hasDomainFlag = 0; */
	uiElmSize += uiSetLength;							/* Add to wElmSize for FSBtReplace()*/

	/* Get the reference length and hasDomainFlag */
	if( uiSetLength )
	{
		if( *pReference == SEN_DOMAIN )
		{
			/* hasDomainFlag = 1; */
			uiSetLength--;
			uiSetLength -= SENValLen( pReference + 1 );
		}
	}
	if( uiSetLength == 0 )
	{
		FLMBOOL		bLastElm  = BBE_IS_LAST( pElement );
		FLMBOOL		bFirstElm = BBE_IS_FIRST( pElement );

		/* Delete the element */
		if( RC_BAD( rc = FSBtDelete( pDb, pLFile, &pStack )))
			return( rc );

		/**--------------------------------------------------------------------
		*** Remove the LAST (only) reference in an element.
		***
		***	There are 4 cases to consider that deal with continuation elements
		***	1. ONLY element - no list - ALL DONE
		***	2. FIRST of many in a list- Set BBE_FIRST_FLAG in the next element
		***	3. MIDDLE of a list       - ALL DONE
		***	4. LAST in a list         -
		***    Remove the domain from the previous element and
		***    set the BBE_LAST_FLAG in the new last element.
		***-------------------------------------------------------------------*/

		if( bFirstElm && bLastElm)						/* Case 1 - ONLY element */
		{
			*pbSingleRef = TRUE;
		}
		else if( bFirstElm && (! bLastElm ))		/* Case 2 - first of many */
		{
			/* Log the block before modifying it. */
			if( RC_BAD( rc = FSLogPhysBlk( pDb, pStack)))
				return( rc);

			pElement = CURRENT_ELM( pStack );
			BBE_SET_FIRST( pElement );
		}

		else if( !bFirstElm && bLastElm )			/* Case 4 - Last in a list */
		{
			/**---------------------------------------------------
			***	Element was either the ONLY or LAST in a list.
			***--------------------------------------------------*/

			FSBtPrevElm( pDb, pLFile, pStack );		/* Goto the previous element */

			pElement = CURRENT_ELM( pStack );

			pReference = BBE_REC_PTR( pElement );
			uiSetLength = BBE_GET_RL( pElement );
			uiKeyLen = pStack->uiKeyLen;

			/* Build the element in byElmBuf[] - sets BBE_FIRST_FLAG if set */
			FSSetElmOvhd( byElmBuf, BBE_KEY, 0, uiKeyLen, pElement );
			BBE_SET_LAST( byElmBuf );						/* Set last element flag */

			f_memcpy( &byElmBuf[ BBE_KEY ], pStack->pKeyBuf, uiKeyLen);
			pDestRefPtr = &byElmBuf[ BBE_KEY + uiKeyLen ];
			/* Parse past the element information and delete the domain data*/
		
			if( *pReference != SEN_DOMAIN)
				return( RC_SET( FERR_BTREE_ERROR) );

			uiSenLen = 	(SENValLen( pReference + 1) + 1);
			pReference += uiSenLen;
			uiSetLength -= uiSenLen;
			f_memcpy( pDestRefPtr, pReference, uiSetLength );
			BBE_SET_RL( byElmBuf, uiSetLength );

			uiElmSize = (BBE_KEY + uiKeyLen + uiSetLength);		/* Recompute wElmSize */

			/**
			*** We could call FSBtReplace() except that if the element
			*** is the last element in the block, the parent element
			*** will still contain the 3 byte non-leaf DOMAIN number which
			*** should no longer exist.  In addition, the BBE_LAST_FLAG
			*** flag should be set in the current element and replace doesn't
			*** do that.
			**/
			if( RC_BAD(rc = FSBtDelete( pDb, pLFile, &pStack )))
				return( rc );

			/**-----------------------------------------------------------------
			***	 POSSIBLE CHECK YOU MAY FORGET...
			***  You could have deleted the ONLY element in the tree.
			***  Check and if so init a new root block and position for insert.
			***----------------------------------------------------------------*/
			if( pLFile->uiRootBlk == BT_END )
			{
				if( RC_BAD( rc = flmLFileInit( pDb, pLFile)))
				{
					return( rc);
				}

				/* Call FSBtSearch to setup the pStack, would rather do a goto top; */
				if( RC_BAD(rc = FSBtSearch( pDb, pLFile, &pStack,
													 (FLMBYTE *) &byElmBuf[BBE_KEY],
													 uiKeyLen, 0 )))
				{
					return( rc);
				}
			}
			else
			{
				/* BUG #18811 8/14/96 - had == in the code.
					Added the rc checking in June.
					The DIN_DOMAIN for this new element is 0 because scanto()
					will go to wCurElm.
				*/
				/* Setup the pStack and bsKeyBuf[] for the insert */
				if( RC_BAD(rc = FSBtScanTo( pStack, &byElmBuf[ BBE_KEY ], 
													  uiKeyLen, 0)))
				{
					goto Exit;
				}
			}

			rc = FSBtInsert( pDb, pLFile, &pStack, byElmBuf, uiElmSize );
		}
	}
	else
	{
		/* Replace the current element - wElmSize has had uiSetLength added to it */
		rc = FSBtReplace( pDb, pLFile, &pStack, byElmBuf, uiElmSize );
	}

	if( RC_BAD( rc))
	{
		goto Exit;
	}
	
Exit:

	return( rc );
}

/****************************************************************************
Desc:		Delete a single reference into a reference set.  This is the code
			that supports the new DIN (Dual Integer Numbers) format for reference
			set compression.
Notes: 	This code is optimized for adding references to the front.
****************************************************************************/	
RCODE FSSetDeleteRef(
	FLMBYTE *		pDestRef,
	FLMBYTE *		pSrcRef,
	FLMUINT			drn,
	FLMUINT *		puiSetLength)			/* returns the current length of the set */
{
	DIN_STATE		destState, srcState;		/* State destination & source info */
	FLMUINT			uiSetLength = *puiSetLength;	/* Source set length */
	FLMUINT			uiMoveLen;
	FLMUINT			uiLastSrcOfs;				/* Last accessed source offset value */	
	FLMUINT			uiLastDrn;					/* Last din before one tobe Deleted */
	FLMUINT			uiOldDelta;					/* If deleting at front value=0 */
	FLMUINT			uiOneRun;					/* Value of one runs */
	FLMUINT			uiTemp;
	FLMBYTE			byValue;						/* Temporary byte value - register */

	/* Initialization Section */
	RESET_DINSTATE( destState );
	RESET_DINSTATE( srcState );
	uiLastSrcOfs = 0;

	/* Take care of the domain value */
	if( *pSrcRef == SEN_DOMAIN)
	{
		srcState.uiOffset = 1;
		uiLastDrn = DINNextVal( pSrcRef, &srcState );
		uiLastSrcOfs = srcState.uiOffset;
	}

	uiLastDrn = DINNextVal( pSrcRef, &srcState );

	if( drn > uiLastDrn)						/* Greater than the first reference */
	{
		return( RC_SET( FERR_KEY_NOT_FOUND) );
	}
	if( drn == uiLastDrn)
	{
		/**
		***		MATCHED THE FIRST REFERENCE
		***		Write the replacement starting DRN and fix 1 run if there.
		**/
		if( uiLastSrcOfs)								/* If domain - copy it */
			f_memcpy( pDestRef, pSrcRef, destState.uiOffset = uiLastSrcOfs);

		if( srcState.uiOffset >= uiSetLength)	/* Only 1 reference */
			goto FSSDR_done;

		byValue = pSrcRef[ srcState.uiOffset ];
		if( DIN_IS_REAL_ONE_RUN( byValue ))				/* Run of 2 or above */
		{
			DINPutNextVal( pDestRef, &destState, uiLastDrn - 1 );
			DINPutOneRunVal( pDestRef, &destState, 
								  DINOneRunVal( pSrcRef,&srcState)-1);
		}
		else
		{
			uiLastDrn -= DINNextVal( pSrcRef, &srcState );
			DINPutNextVal( pDestRef, &destState, uiLastDrn );
		}
		goto FSSDR_move_rest_of_dins;
	}

	uiOldDelta = uiLastDrn;
	uiOneRun = 0;
	/**
	***		Search through the set finding where the "din" fits in.
	***		Similar while loop as the while loop in FSSetInsertRef() above.
	**/
	while( drn < uiLastDrn)
	{
		uiLastSrcOfs = srcState.uiOffset;

		uiOneRun = 0;

		if( srcState.uiOffset >= uiSetLength)	/* Check if at end */
		{
			return( RC_SET( FERR_KEY_NOT_FOUND) );
		}

		/**
		***		Check for a run of ONE's
		**/
		byValue = pSrcRef[ srcState.uiOffset ];
		if( DIN_IS_REAL_ONE_RUN( byValue ))	/* Only consider one runs >= 2 */
		{
			/* Read the number of one runs */
			uiOneRun = DINOneRunVal( pSrcRef, &srcState );
			uiLastDrn -= uiOneRun;			/* This could make uiLastDrn < drn */
		}
		else
		{
			uiOldDelta = DINNextVal( pSrcRef, &srcState );
			uiLastDrn -= uiOldDelta;
		}
	}	/* End while( drn < uiLastDrn) */
			
	f_memcpy( pDestRef, pSrcRef, destState.uiOffset = uiLastSrcOfs);

	if( uiOneRun )
	{
		/**-------------------------------------------------***
		***		Divide out a one run.  drn may match the   		***
		***		first, middle or last value of a one run.			***
		***		Copy up to the last source value to dest.			***
		***-------------------------------------------------**/
		
		uiLastDrn += uiOneRun;				/* Reset uiLastDrn back to > drn */

		if( drn == uiLastDrn - 1 )			/* Delete FIRST one run */
		{
			/* Remove the first value from the run - run is >= 2 */
			DINPutNextVal( pDestRef, &destState, 2 );
			if( uiOneRun > 2 )
			{
				DINPutOneRunVal( pDestRef, &destState, uiOneRun - 2);
			}
			goto FSSDR_move_rest_of_dins;
		}
		else 
		{
			DINPutOneRunVal( pDestRef, &destState, (uiLastDrn - drn) - 1 );
			
			if( drn > uiLastDrn - uiOneRun )		/* Delete from the MIDDLE of one run*/
			{
				FLMUINT oneRun2ndHalf = uiOneRun - (uiLastDrn - drn) - 1;
				
				DINPutNextVal( pDestRef, &destState, 2);
				if( oneRun2ndHalf)
					DINPutOneRunVal( pDestRef, &destState, oneRun2ndHalf );
				goto FSSDR_move_rest_of_dins;
			}
			else
			{
				/* Delete from the END of a one run */
				uiOldDelta = 1;
				goto FSSDR_combine_2_deltas;
			}
		}	
		/* Should never reach here! */			
	}
	/* Check for duplicates */
	else if( drn != uiLastDrn)
		return( RC_SET( FERR_KEY_NOT_FOUND) );
	/* implied else */
		
	/**
	***	Hit a non-one run where drn == uiLastDrn
	***	Check the next DIN value and add uiOldDelta to it
	***	UNLESS it is a one run, then write uiOldDelta+1 and
	***	if uiOneRun-1 is non-zero then write uiOneRun-1
	**/

	/* Check for a run of ONE's */
	if( srcState.uiOffset < uiSetLength )
	{
		byValue = pSrcRef[ srcState.uiOffset ];
		if( DIN_IS_REAL_ONE_RUN( byValue ))
		{
			DINPutNextVal( pDestRef, &destState, uiOldDelta + 1 );
			uiOneRun = DINOneRunVal( pSrcRef, &srcState ) - 1;
			DINPutOneRunVal( pDestRef, &destState, uiOneRun );
		}
		else		/* else combine the next delta with the preceeding delta */
		{

FSSDR_combine_2_deltas:
			if( srcState.uiOffset >= uiSetLength)
				goto FSSDR_done;

			uiTemp = DINNextVal(pSrcRef, &srcState);		/* 2 lines for debugging */
			DINPutNextVal( pDestRef, &destState, uiOldDelta + uiTemp );
		}
	}	

FSSDR_move_rest_of_dins:
	if( (uiMoveLen = (FLMUINT)(uiSetLength - srcState.uiOffset) ) != 0)
	{
		f_memcpy( &pDestRef[ destState.uiOffset ],
							&pSrcRef[  srcState.uiOffset ], uiMoveLen );
		destState.uiOffset += uiMoveLen;
	}

FSSDR_done:
	*puiSetLength = destState.uiOffset;
	
#ifdef REF_TESTING
	uiSetLength = destState.uiOffset;
	if( uiSetLength && drn < 512)
	{
		int colPos = 1;
		printf("%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Deleting %ld\n", drn);
		uiLastDrn = 0;
		RESET_DINSTATE( destState );
		if( *pDestRef == SEN_DOMAIN)
				printf("DOMAIN: %ld\n", DINNextVal( pDestRef, &destState ));
		uiLastDrn = DINNextVal( pDestRef, &destState );		
		printf(" %4ld ", uiLastDrn );
		while( destState.uiOffset < uiSetLength)
		{
			byValue = pDestRef[ destState.uiOffset ];
			if( DIN_IS_ONE_RUN( byValue ))	/* uiOneRun must be set if a 1 */
			{
				/* Read the number of one runs */
				printf("R%4ldR", uiOneRun = DINOneRunVal( pDestRef, &destState ));
				uiLastDrn -= uiOneRun;
			}
			else
			{
				uiOldDelta = DINNextVal( pDestRef, &destState );
				uiLastDrn -= uiOldDelta;
				printf(" %4ld ", uiLastDrn );
			}
			if( colPos++ > 9)
			{
				printf("\n");
				colPos = 0;	
			}
		}	
		printf("\n");
	}
#endif

	return( FERR_OK );
}

/***************************************************************************
Desc:		Put a SEN value into a buffer - return the length of storage used
Notes:	goto's used to save code space and maybe speed up code!
*****************************************************************************/
FLMUINT SENPutNextVal(
	FLMBYTE **		pSenRV,			/* Points to a SEN buffer */
	FLMUINT			senValue			/* SEN value */
	)
{
	FLMBYTE *		pSen = *pSenRV;
	FLMUINT			uiSenLen;
	
	if( senValue <= SEN_1B_VAL)
	{
		*pSen++ = (FLMBYTE) senValue;
	}
	else if( senValue <= SEN_2B_VAL)
	{
		*pSen++ = (FLMBYTE)(SEN_2B_CODE + (FLMBYTE) ((senValue >> 8) & SEN_2B_MASK ));
		*pSen++ = (FLMBYTE) senValue;
		/* Don't bother with goto */
	}
	else if( senValue <= SEN_3B_VAL)
	{
		*pSen++ = (FLMBYTE)(SEN_3B_CODE + (FLMBYTE) ((senValue >> 16) & SEN_3B_MASK ));
		goto SENPV_2_bytes;
	}
	else if( senValue <= SEN_4B_VAL)
	{
		*pSen++ = (FLMBYTE)(SEN_4B_CODE + (FLMBYTE) ((senValue >> 24) & SEN_4B_MASK ));
		goto SENPV_3_bytes;
	}
	else
	{
		*pSen++ = SEN_5B_CODE;				/* 0 value in left 4 bits ALWAYS */
		*pSen++ = (FLMBYTE) (senValue >> 24);
SENPV_3_bytes:
		*pSen++ = (FLMBYTE) (senValue >> 16);
SENPV_2_bytes:
		*pSen++ = (FLMBYTE) (senValue >> 8);
/*SENPV_1_byte:*/
		*pSen++ = (FLMBYTE) senValue;
	}
		
	uiSenLen = (FLMUINT) (pSen - *pSenRV);
	/* wSenLen = SENLenArray[ **pSenRV	>> 4 ]; this could be faster??? */

	*pSenRV = pSen;
	return( uiSenLen );
}

/****************************************************************************
Desc:  	Put the next one run value - high level 
****************************************************************************/
FLMUINT DINPutOneRunVal( 
	FLMBYTE *		dinPtr,
	DIN_STATE_p		state,
	FLMUINT			uiValue)
{
	FLMUINT			uiLength = 1;					/* Default */
	FLMUINT			uiOffset = state->uiOffset;
	FLMBYTE *		pOneRun;

	if( uiValue == 1)
	{
		dinPtr[ uiOffset ] = 1;
	}
	else if( uiValue <= DIN_MAX_1B_ONE_RUN)
	{
		dinPtr[ uiOffset ] = (FLMBYTE)(DIN_ONE_RUN_LV | (((FLMBYTE) uiValue) - 2));
	}
	else
	{
		dinPtr[ uiOffset ] = DIN_ONE_RUN_HV;
		pOneRun = &dinPtr[ uiOffset + 1 ];
				
		uiLength += SENPutNextVal( &pOneRun, uiValue );
	}
	state->uiOffset += uiLength;
	/* See if faster to set state->uiOffset = uiLength + uiOffset */
	return( uiLength );
}