Renamed version4 to flaim and version5 to xflaim
git-svn-id: https://svn.code.sf.net/p/flaim/code/trunk@7 0109f412-320b-0410-ab79-c3e0c5ffbbe6
This commit is contained in:
dsandersoremutah
319
flaim/src/fsrefspl.cpp
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319
flaim/src/fsrefspl.cpp
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//-------------------------------------------------------------------------
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// Desc: Index reference splitting routines.
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// Tabs: 3
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//
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// Copyright (c) 1991-2000,2002-2006 Novell, Inc. All Rights Reserved.
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of version 2 of the GNU General Public
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// License as published by the Free Software Foundation.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, contact Novell, Inc.
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//
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// To contact Novell about this file by physical or electronic mail,
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// you may find current contact information at www.novell.com
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//
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// $Id: fsrefspl.cpp 12286 2006-01-19 14:55:18 -0700 (Thu, 19 Jan 2006) dsanders $
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//-------------------------------------------------------------------------
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#include "flaimsys.h"
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FSTATIC FLMUINT FSSplitRefSet(
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FLMBYTE * leftBuf,
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FLMUINT * leftLenRV,
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FLMBYTE * rightBuf,
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FLMUINT * rightLenRV,
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FLMBYTE * refPtr,
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FLMUINT uiRefLen,
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FLMUINT uiSplitFactor);
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/****************************************************************************
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Desc: Try to split a reference set. The size is over the first threshold.
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If you split this update the b-tree with the new element and position
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to the current element for insert of the din.
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Out: The element may be split, or may not. It is not the callers concern.
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****************************************************************************/
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RCODE FSRefSplit(
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FDB * pDb,
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LFILE * pLFile,
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BTSK_p * pStackRV, /* Stack area */
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FLMBYTE * pElmBuf, /* Setup with elements key */
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FLMUINT din, /* din to insert */
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FLMUINT uiDeleteFlag, /* Set if you are to delete din */
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FLMUINT uiSplitFactor) /* Set to SPLIT_90_10 | SPLIT_50_50*/
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{
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RCODE rc = FERR_OK; /* Must be set */
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BTSK_p pStack = *pStackRV; /* Stack may change on you! */
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FLMBYTE * pCurElm = CURRENT_ELM( pStack );/* Points to current element*/
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FLMINT iElmLen; /* Length of element in pElmBuf[] */
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FLMBYTE leftBuf[ MAX_REC_ELM ]; /* Left buffer */
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FLMUINT leftDomain;
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FLMUINT leftLen;
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FLMBYTE rightBuf[MAX_REC_ELM ]; /* Right (current) buffer */
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FLMUINT rightDomain;
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FLMUINT rightLen;
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FLMBYTE * refPtr; /* Points to the references */
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FLMBYTE * recPtr;
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FLMUINT uiRefLen; /* Length of references */
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FLMUINT firstFlag = 0;
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refPtr = pCurElm;
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recPtr = BBE_REC_PTR( pCurElm );
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rightDomain = FSGetDomain( &refPtr, (FLMBYTE)pStack->uiElmOvhd );
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uiRefLen = (FLMUINT)(BBE_GET_RL( pCurElm ) - (FLMUINT)(refPtr - recPtr));
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FSRS_try_again:
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leftDomain = FSSplitRefSet( leftBuf, &leftLen, rightBuf, &rightLen,
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refPtr, uiRefLen, uiSplitFactor );
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if( leftDomain == 0) /* Split failed, setup to add */
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{
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/* Try again using a different split factor - OK to fail above */
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/* In the future, should just handle no splitting and go on */
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if( uiSplitFactor == SPLIT_50_50)
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{
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uiSplitFactor = SPLIT_90_10;
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goto FSRS_try_again;
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}
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#if 0
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return( RC_SET( FERR_BTREE_ERROR)); /* Can't handle this right now */
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#else
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/* Setup for inserting the din into the right buffer and call replace */
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leftDomain = DIN_DOMAIN(din) + 1;
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f_memcpy( rightBuf, refPtr, rightLen = uiRefLen );
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leftLen = 0;
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#endif
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}
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/**
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*** Write the right element's references.
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*** Write the right domain if non-zero and replace element
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**/
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iElmLen = (FLMINT)(BBE_REC_OFS( pElmBuf ));
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refPtr = recPtr = &pElmBuf[ iElmLen ];
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if( rightDomain) /* Write the domain if present */
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{
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*refPtr++ = SEN_DOMAIN;
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SENPutNextVal( &refPtr, rightDomain );
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}
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if( DIN_DOMAIN(din) < leftDomain) /* Remember references DESCEND */
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{
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/* Build element inserting the input din */
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if( uiDeleteFlag)
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{
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if( FSSetDeleteRef( refPtr, rightBuf, din, &rightLen))
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{
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/* rightLen should not have changed if error found */
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return ( RC_SET( FERR_KEY_NOT_FOUND) );
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#if 0
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f_memcpy( refPtr, rightBuf, rightLen );
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rc = RC_SET( FERR_KEY_NOT_FOUND); /* Return with this error */
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#endif
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}
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}
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else if( FSSetInsertRef( refPtr, rightBuf, din, &rightLen ))
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{
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/* Reference there so give up and return success */
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goto Exit; /* rc is set to FERR_OK */
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}
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}
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else
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f_memcpy( refPtr, rightBuf, rightLen );
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/* The other flags and lengths are been set by the caller */
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iElmLen += BBE_SET_RL( pElmBuf, rightLen + (FLMUINT) (refPtr - recPtr ));
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if( BBE_IS_FIRST( pElmBuf ) && leftLen)
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{
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firstFlag++;
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BBE_CLR_FIRST( pElmBuf ); /* Element will no longer be first */
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/* Log the block before modifying it. */
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if( RC_BAD( rc = FSLogPhysBlk( pDb, pStack)))
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goto Exit;
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pCurElm = CURRENT_ELM( pStack );/* Points to current element*/
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BBE_CLR_FIRST( pCurElm ); /* Clear first flag */
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/* Call replace below because FIRST flag is now clear */
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}
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/* Can call replace because FIRST flag was NOT set */
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if( RC_BAD( rc = FSBtReplace( pDb, pLFile, &pStack, pElmBuf, iElmLen )))
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goto Exit;
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/**
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*** Write the left buffer
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*** Should be positioned to the right buffer
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***
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**/
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if( leftLen)
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{
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/**
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*** Adjust variables to build and point to the
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*** left buffers references. Set the domain
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*** and insert into the b-tree. Then go to the next element
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**/
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BBE_CLR_LAST( pElmBuf ); /* Element will no longer be last */
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if( firstFlag)
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BBE_SET_FIRST( pElmBuf);
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iElmLen = (FLMINT)(BBE_REC_OFS( pElmBuf ));
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refPtr = recPtr = &pElmBuf[ iElmLen ];
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*refPtr++ = SEN_DOMAIN;
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SENPutNextVal( &refPtr, leftDomain );
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if( DIN_DOMAIN(din) >= leftDomain)
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{
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/* Build element inserting the input din */
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if( uiDeleteFlag)
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{
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if( FSSetDeleteRef( refPtr, leftBuf, din, &leftLen))
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return( RC_SET( FERR_KEY_NOT_FOUND ));
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}
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else
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/* If this returned with an error code, is alreay in set */
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if( FSSetInsertRef( refPtr, leftBuf, din, &leftLen ))
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f_memcpy( refPtr, leftBuf, leftLen );
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}
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else
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f_memcpy( refPtr, leftBuf, leftLen );
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iElmLen += BBE_SET_RL( pElmBuf, leftLen + (FLMUINT) (refPtr - recPtr));
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/* Setup the pStack and bsKeyBuf[] for the insert */
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if( RC_BAD(rc = FSBtScanTo( pStack, &pElmBuf[ BBE_KEY ],
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(FLMUINT)(BBE_GET_KL(pElmBuf)), 0)))
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goto Exit;
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rc = FSBtInsert( pDb, pLFile, &pStack, pElmBuf, iElmLen );
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}
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Exit:
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return( rc );
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}
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/****************************************************************************
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Desc: Split a reference set within a domain value. If buffer cannot be
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split then will return a leftDomain value of ZERO.
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Must have a minimum of 2 references in left and right buffers.
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Out: References split to the left or right buffers.
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Return: 0 if the split failed, else the leftDomain value
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Notes: Two references are needed in each side because one reference may
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be deleted leaving the left buffer with a domain & maybe should not.
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****************************************************************************/
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FSTATIC FLMUINT FSSplitRefSet(
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FLMBYTE * leftBuf,
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FLMUINT * leftLenRV,
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FLMBYTE * rightBuf,
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FLMUINT * rightLenRV,
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FLMBYTE * refPtr,
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FLMUINT uiRefLen,
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FLMUINT uiSplitFactor) /* Set to SPLIT_90_10 | SPLIT_50_50*/
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{
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FLMUINT leftDomain = 0;
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FLMUINT din = 0;
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FLMUINT oneRuns = 0;
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FLMUINT delta;
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FLMUINT rightLen;
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FLMUINT offsetTarget = (uiSplitFactor == SPLIT_90_10)
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? REF_SPLIT_90_10 : REF_SPLIT_50_50;
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DIN_STATE leftState, rightState, refState;
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FLMBYTE byValue;
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FLMUINT uiLeftCnt;
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RESET_DINSTATE( leftState );
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RESET_DINSTATE( rightState);
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RESET_DINSTATE( refState );
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/* Read the first din value */
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din = DINNextVal( refPtr, &refState );
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DINPutNextVal( leftBuf, &leftState, din );
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uiLeftCnt = 1;
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// Must have at least 2 in the left buffer.
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while( refState.uiOffset < offsetTarget || uiLeftCnt < 2)
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{
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byValue = refPtr[ refState.uiOffset ];
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if( DIN_IS_REAL_ONE_RUN( byValue ))
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{
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oneRuns = DINOneRunVal( refPtr, &refState );
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DINPutOneRunVal( leftBuf, &leftState, oneRuns );
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din -= oneRuns;
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}
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else
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{
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delta = DINNextVal( refPtr, &refState );
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DINPutNextVal( leftBuf, &leftState, delta );
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din -= delta;
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}
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uiLeftCnt++;
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}
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/* Made it past the target point - find where domain changes */
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leftDomain = DIN_DOMAIN( din );
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/* Don't parse past the end */
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while( refState.uiOffset < uiRefLen)
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{
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byValue = refPtr[ refState.uiOffset ];
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if( DIN_IS_REAL_ONE_RUN( byValue ))
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{
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oneRuns = DINOneRunVal( refPtr, &refState );
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if( DIN_DOMAIN(din-oneRuns) != leftDomain)
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{
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/* This is tricky, write only correct number of one runs */
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delta = din & 0xFF;
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if( delta)
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DINPutOneRunVal( leftBuf, &leftState, delta );
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/* Increment delta because setting up for next element */
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delta++;
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oneRuns -= delta;
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/* Write din and one runs below */
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din -= delta;
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break;
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}
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DINPutOneRunVal( leftBuf, &leftState, oneRuns );
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din -= oneRuns;
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}
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else
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{
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delta = DINNextVal( refPtr, &refState );
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din -= delta;
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if( DIN_DOMAIN(din) != leftDomain)
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{
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oneRuns = 0;
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break;
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}
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DINPutNextVal( leftBuf, &leftState, delta );
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}
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}
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if( refState.uiOffset == uiRefLen)
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return( 0 ); /* Cannot split, caller take care of*/
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/* Start writing to the right side, compare /w uiRefLen proves > 2 refs */
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DINPutNextVal( rightBuf, &rightState, din );
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if( oneRuns)
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DINPutOneRunVal( rightBuf, &rightState, oneRuns );
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*leftLenRV = leftState.uiOffset;
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rightLen = (FLMUINT)(uiRefLen - refState.uiOffset);
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f_memcpy( &rightBuf[ rightState.uiOffset ],
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&refPtr[ refState.uiOffset ],
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rightLen );
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*rightLenRV = rightLen + rightState.uiOffset;
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return( leftDomain );
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}
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