initial commit into svn repository

git-svn-id: http://svn.klever.net/kin/T42/trunk@1 fe716a7a-6dde-0310-88d9-d003556173a8

1 files changed, 595 insertions, 0 deletions

diff --git a/shared-code/BTreendex.h b/shared-code/BTreendex.h
new file mode 100644
index 0000000..88109ab
--- a/dev/null
+++ b/shared-code/BTreendex.h
@@ -0,0 +1,595 @@
+#ifndef	__BTREENDEX_H

+#define	__BTREENDEX_H

+

+#include "Dynamide.h"

+

+namespace Klever {

+

+template<class key,class value,int treeOrder,int cluster>

+class	CBTreendex	: public CObject	{

+public:

+	typedef LONG CBTPageRef;

+	struct CBTRecordRef {

+		CBTPageRef m_Page;

+		INT m_Offset;

+		CBTRecordRef(CBTPageRef page=-1,INT offset=-1) : m_Page(page), m_Offset(offset) {}

+	};

+	class CBTRecord : public CObject {

+	public:

+		CBTPageRef m_ptrLeft;

+		CBTPageRef m_ptrRight;

+		key m_Key;

+		value m_Value;

+		CBTRecord() : m_ptrLeft(-1), m_ptrRight(-1) {}

+		CBTRecord(key& _key,value& _value,CBTPageRef left=-1,CBTPageRef right=-1) : m_Key(_key), m_Value(_value), m_ptrLeft(left), m_ptrRight(right) {}

+		CBTRecord(CBTRecord& r) : m_Key(r.m_Key), m_Value(r.m_Value), m_ptrLeft(r.m_ptrLeft), m_ptrRight(r.m_ptrRight) {}

+

+		CBTRecord& operator=(CBTRecord& r) {m_Key=r.m_Key, m_Value=r.m_Value, m_ptrLeft=r.m_ptrLeft, m_ptrRight=r.m_ptrRight;return *this;}

+

+		void Serialize(CArchive& ar) {

+			if(ar.IsStoring()){

+				ar << m_ptrLeft;

+				ar << m_ptrRight;

+			}else{

+				ar >> m_ptrLeft;

+				ar >> m_ptrRight;

+			}

+			SerializeElements(ar,&m_Key,1);

+			SerializeElements(ar,&m_Value,1);

+		}

+	};

+	class CBTPage : public CArray<CBTRecord,CBTRecord&> {

+	public:

+		void Serialize(CArchive& ar) {

+		int nCount = -1;

+			if(ar.IsStoring()){

+				nCount = GetSize();

+				ar << nCount;

+			}else{

+				nCount = 0;

+				ar >> nCount;

+				RemoveAll();

+				SetSize(nCount);

+			}

+			for(int tmp=0;tmp<nCount;tmp++)

+				ElementAt(tmp).Serialize(ar);

+		}

+	};

+	typedef CDynamide<256,cluster> CBTDyna;

+	typedef CBTDyna::CDynaFile CBTDynaFile;

+	typedef CArray<CBTRecordRef,CBTRecordRef&> CBTRStack;

+

+	CBTDyna m_BT;

+	struct	_btCrap {

+		BOOL m_bRootSet;

+		CBTPageRef m_Root;

+	} *m_BTCrap;

+	BOOL m_bRO;

+	CBTRStack m_btStack;

+	CBTPage m_stackTop;

+

+	CBTreendex() {}

+	~CBTreendex() { Close(); }

+	BOOL Attach(CFile* file,BOOL bAutodelete) {

+		m_bRO = FALSE;

+		if(!m_BT.Attach(file,bAutodelete))

+			return FALSE;

+		return Attach();

+	}

+	BOOL Open(LPCTSTR file,BOOL bReadOnly) {

+		if(!m_BT.Open(file,bReadOnly))

+			return FALSE;

+		m_bRO = bReadOnly;

+		return Attach();

+	}

+	BOOL Create(LPCTSTR file) {

+		try{

+		CFile* f = new CFile(file,CFile::modeCreate|CFile::modeReadWrite|CFile::shareDenyRead|CFile::shareDenyWrite|CFile::typeBinary);

+			ASSERT(f);

+			return Attach(f,TRUE);

+		}catch(CException* e){

+			e->Delete();

+			return FALSE;

+		}

+	}

+	BOOL Attach() {

+		ASSERT(m_BT.IsOpened());

+		m_BTCrap = (_btCrap*)m_BT.m_FB.crap;

+		if(!m_BTCrap->m_bRootSet){

+			m_BTCrap->m_Root = AllocatePage();

+			if(m_BTCrap->m_Root<0)

+				return FALSE;

+			m_BTCrap->m_bRootSet = TRUE;

+			m_BT.Write1stBlock();

+		}

+		return TRUE;

+	}

+	BOOL Close() {

+		m_BT.Close();

+		return TRUE;

+	}

+	BOOL IsOpened() {

+		return m_BT.IsOpened();

+	}

+

+	BOOL Lookup(key& _key,value& value) {

+		if(!IsOpened())

+			return FALSE;

+		ASSERT(m_BTCrap->m_bRootSet);

+		if(!SeekToPage(_key))

+			return FALSE;

+	CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+		if(rr.m_Offset<0)

+			return FALSE;

+		ASSERT(rr.m_Offset<m_stackTop.GetSize());

+		if(_key != m_stackTop[rr.m_Offset].m_Key)

+			return FALSE;

+		value = m_stackTop[rr.m_Offset].m_Value;

+		return TRUE;

+	}

+	BOOL Add(key& _key,value& _value) {

+		if(!IsOpened())

+			return FALSE;

+		ASSERT(m_BTCrap->m_bRootSet);

+		if(!SeekToPage(_key))

+			return FALSE;

+	CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+	CBTRecord nuRecord(_key,_value);

+		if(rr.m_Offset<0){

+			if(m_stackTop.GetSize())

+				nuRecord.m_ptrLeft = m_stackTop[m_stackTop.GetUpperBound()].m_ptrRight;

+		}else if(rr.m_Offset==0){

+			nuRecord.m_ptrRight = m_stackTop[0].m_ptrLeft;

+		}else{

+			nuRecord.m_ptrLeft = m_stackTop[rr.m_Offset-1].m_ptrRight;

+			nuRecord.m_ptrRight = m_stackTop[rr.m_Offset].m_ptrLeft;

+		}

+//		ASSERT(rr.m_Offset==0 || (m_stackTop[rr.m_Offset-1].m_Key<_key && m_stackTop[rr.m_Offset-1].m_ptrRight<0));

+//		ASSERT(rr.m_Offset<0 || m_stackTop[rr.m_Offset].m_Key>=_key && m_stackTop[rr.m_Offset].m_ptrLeft<0);

+		if(rr.m_Offset>=0 && m_stackTop[rr.m_Offset].m_Key==_key){

+			// Exact match found - just replace.

+			m_stackTop[rr.m_Offset].m_Value = _value;

+			if(!SavePage(rr.m_Page,m_stackTop))

+				return FALSE;

+			return TRUE;

+		}

+		// Split the page and propagate the split if needed..

+		// Insert new element at rr.m_Offset..

+	BOOL nuisnew = TRUE;

+		for(int sp=m_btStack.GetUpperBound();sp>=0;sp--){

+		CBTPageRef opr = m_btStack[sp].m_Page;

+		int iAt = m_btStack[sp].m_Offset;

+		CBTPage op;

+			VERIFY(LoadPage(opr,op));

+			if(iAt<0)

+				iAt = op.GetSize();

+			else{

+				if(op[iAt].m_Key<nuRecord.m_Key)

+					iAt++;

+				ASSERT(iAt==op.GetSize() || op[iAt].m_Key > nuRecord.m_Key);

+			}

+			op.InsertAt(iAt,nuRecord);

+			if(iAt>0)

+				op[iAt-1].m_ptrRight=nuRecord.m_ptrLeft;

+			if(iAt<op.GetUpperBound())

+				op[iAt+1].m_ptrLeft=nuRecord.m_ptrRight;

+			if(op.GetSize()<=treeOrder*2){

+				// This isn't causing overflow

+				VERIFY(SavePage(opr,op));

+				return TRUE;

+			}

+			TRACE0("Split\n");

+			ASSERT(op.GetSize()==(treeOrder*2+1));

+		CBTPageRef npr = AllocatePage();

+			ASSERT(npr>=0);

+		CBTPage np;

+			ASSERT(LoadPage(npr,np));

+			ASSERT(!np.GetSize());

+			nuRecord = op[treeOrder];

+			if(iAt==treeOrder){

+				// We're inserting central element! - drop out the stack top if this is still new one

+				for(int tmp=0;tmp<treeOrder;tmp++)

+					np.InsertAt(tmp,op[tmp]);

+				op.RemoveAt(0,treeOrder+1);

+				nuRecord.m_ptrLeft = npr;

+				nuRecord.m_ptrRight = opr;

+				if(nuisnew)

+					m_btStack.RemoveAt(m_btStack.GetUpperBound());

+			}else{

+				if(iAt<treeOrder){

+					// We're inserting in the left subtree.

+					// Make newpage the right one and forget it.

+					for(int tmp=0;tmp<treeOrder;tmp++)

+						np.InsertAt(tmp,op[tmp+treeOrder+1]);

+					op.RemoveAt(treeOrder,treeOrder+1);

+					nuRecord.m_ptrLeft = opr;

+					nuRecord.m_ptrRight = npr;

+				}else{

+					// We're inserting in the right subtree.

+					// Make newpage the left one, forget it, but also adjust offset in the stack

+					for(int tmp=0;tmp<treeOrder;tmp++)

+						np.InsertAt(tmp,op[tmp]);

+					op.RemoveAt(0,treeOrder+1);

+					nuRecord.m_ptrLeft = npr;

+					nuRecord.m_ptrRight = opr;

+					m_btStack[sp].m_Offset-=treeOrder+1;

+				}

+				// Note that we're not inserting new element anymore.

+				nuisnew = FALSE;

+			}

+			// Do, excessive sanity checks and save pages

+			ASSERT(op.GetSize());

+			ASSERT(np.GetSize());

+			VERIFY(SavePage(opr,op));

+			VERIFY(SavePage(npr,np));

+		}

+		// Here we have root page overflow, which means that we're simply putting new

+		// record in this brand new root page and also inserting this page on the bottom of the stack

+	CBTPageRef nuroot = AllocatePage();

+		ASSERT(nuroot>=0);

+	CBTPage nurpa;

+		ASSERT(LoadPage(nuroot,nurpa));

+		ASSERT(!nurpa.GetSize());

+		nurpa.Add(nuRecord);

+		VERIFY(SavePage(nuroot,nurpa));

+		m_btStack.InsertAt(0,CBTRecordRef(nuroot,0));

+		m_BTCrap->m_Root = nuroot;

+		m_BT.Write1stBlock();

+		return TRUE;

+	}

+	BOOL Delete(key& _key) {

+		if(!IsOpened())

+			return FALSE;

+		ASSERT(m_BTCrap->m_bRootSet);

+	value _value;

+		if(!Lookup(_key,_value))

+			return FALSE;

+		// Found key, check if it's a leaf

+		{

+		CBTRecordRef* rr = &m_btStack[m_btStack.GetUpperBound()];

+		int rrIdx = m_btStack.GetUpperBound();

+			if(m_stackTop[rr->m_Offset].m_ptrLeft>=0){

+				ASSERT(m_stackTop[rr->m_Offset].m_ptrRight>=0);

+				// It isn't - scan for the _next_ key and do dirty deeds

+				m_btStack.Add(CBTRecordRef(m_stackTop[rr->m_Offset].m_ptrRight,0));

+				for(;;){

+				CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+					if(!LoadPage(rr.m_Page,m_stackTop))

+						return FALSE;

+					if(m_stackTop[0].m_ptrLeft<0)

+						break;

+					m_btStack.Add(CBTRecordRef(m_stackTop[0].m_ptrLeft,0));

+				}

+				// We have a leaf node here, replace victim with the first element and kill it.

+			CBTPage uppage;

+				rr = &m_btStack[rrIdx];

+				if(!LoadPage(rr->m_Page,uppage))

+					return FALSE;

+				uppage[rr->m_Offset].m_Key=m_stackTop[0].m_Key; uppage[rr->m_Offset].m_Value=m_stackTop[0].m_Value;

+				m_stackTop.RemoveAt(0);

+				if(!(SavePage(rr->m_Page,uppage) && SavePage(m_btStack[m_btStack.GetUpperBound()].m_Page,m_stackTop)))

+					return FALSE;

+			}else{

+				ASSERT(m_stackTop[rr->m_Offset].m_ptrRight<0);

+				m_stackTop.RemoveAt(rr->m_Offset);

+				if(!SavePage(rr->m_Page,m_stackTop))

+					return FALSE;

+			}

+		}

+		// We have a page to check for underflow at the top of the stack now.

+		for(;;){

+		CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+			if(!LoadPage(rr.m_Page,m_stackTop))

+				return FALSE;

+			if(m_stackTop.GetSize()>=treeOrder || m_btStack.GetSize()==1)

+				return TRUE;

+		CBTRecordRef& rr1 = m_btStack[m_btStack.GetUpperBound()-1];

+		CBTPage daddy;

+			if(!LoadPage(rr1.m_Page,daddy))

+				return FALSE;

+		CBTPageRef nPage = daddy[rr1.m_Offset].m_ptrRight;

+		BOOL bRight=TRUE;

+			if(nPage<0 || nPage==rr.m_Page){

+				nPage = daddy[rr1.m_Offset].m_ptrLeft;

+				bRight = FALSE;

+			}

+			ASSERT(nPage>=0 && nPage!=rr.m_Page);

+		CBTPage neighbor;

+			if(!LoadPage(nPage,neighbor))

+				return FALSE;

+			// Here we have possibly two cases:

+			// 1. Neighboring page can share some data with use, then do share and leave

+			// 2. Neighboring page is of treeorder in size, then merge and propagate

+			if(neighbor.GetSize()>treeOrder){

+				TRACE0("Redistributing..\n");

+				// Borrow some data from there.

+			int toBorrow = neighbor.GetSize()-treeOrder;

+				toBorrow=toBorrow/2+1;

+				ASSERT(toBorrow);

+				if(bRight)

+					m_stackTop.Add(CBTRecord(daddy[rr1.m_Offset].m_Key,daddy[rr1.m_Offset].m_Value,m_stackTop[m_stackTop.GetUpperBound()].m_ptrRight,neighbor[0].m_ptrLeft));

+				else

+					m_stackTop.InsertAt(0,CBTRecord(daddy[rr1.m_Offset].m_Key,daddy[rr1.m_Offset].m_Value,neighbor[neighbor.GetUpperBound()].m_ptrRight,m_stackTop[0].m_ptrLeft));

+				for(toBorrow--;toBorrow;toBorrow--){

+					if(bRight){

+						m_stackTop.Add(neighbor[0]);

+						neighbor.RemoveAt(0);

+					}else{

+						m_stackTop.InsertAt(0,neighbor[neighbor.GetUpperBound()]);

+						neighbor.RemoveAt(neighbor.GetUpperBound());

+					}

+				}

+				daddy[rr1.m_Offset].m_Key = neighbor[bRight?0:neighbor.GetUpperBound()].m_Key; daddy[rr1.m_Offset].m_Value = neighbor[bRight?0:neighbor.GetUpperBound()].m_Value;

+				neighbor.RemoveAt(bRight?0:neighbor.GetUpperBound());

+				if(!(SavePage(rr1.m_Page,daddy) && SavePage(nPage,neighbor) && SavePage(rr.m_Page,m_stackTop)))

+					return FALSE;

+				rr.m_Offset = -1;	// *** Point to the next??

+				return TRUE;

+			}

+			TRACE0("Merging..\n");

+			// We need to merge pages here..

+			// We will merge them at stacktop, then we'll discard neighbor guy..

+			if(bRight)

+				m_stackTop.Add(CBTRecord(daddy[rr1.m_Offset].m_Key,daddy[rr1.m_Offset].m_Value,m_stackTop[m_stackTop.GetUpperBound()].m_ptrRight,neighbor[0].m_ptrLeft));

+			else

+				m_stackTop.InsertAt(0,CBTRecord(daddy[rr1.m_Offset].m_Key,daddy[rr1.m_Offset].m_Value,neighbor[neighbor.GetUpperBound()].m_ptrRight,m_stackTop[0].m_ptrLeft));

+			if(bRight){

+				while(neighbor.GetSize()){

+					m_stackTop.Add(neighbor[0]);

+					neighbor.RemoveAt(0);

+				}

+			}else{

+				while(neighbor.GetSize()){

+					m_stackTop.InsertAt(0,neighbor[neighbor.GetUpperBound()]);

+					neighbor.RemoveAt(neighbor.GetUpperBound());

+				}

+			}

+			if(rr1.m_Offset>0)

+				daddy[rr1.m_Offset-1].m_ptrRight=rr.m_Page;

+			if(rr1.m_Offset<daddy.GetUpperBound())

+				daddy[rr1.m_Offset+1].m_ptrLeft=rr.m_Page;

+			daddy.RemoveAt(rr1.m_Offset);

+			if(!(SavePage(rr1.m_Page,daddy) && SavePage(rr.m_Page,m_stackTop)))

+				return FALSE;

+			VERIFY(DeallocatePage(nPage));

+			m_btStack.RemoveAt(m_btStack.GetUpperBound());

+		}

+		return FALSE;

+	}

+	BOOL GoFirst() {

+		if(!IsOpened())

+			return FALSE;

+		ASSERT(m_BTCrap->m_bRootSet);

+		m_btStack.RemoveAll();

+		m_btStack.Add(CBTRecordRef(m_BTCrap->m_Root,-1));

+		for(;;){

+		CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+			if(!LoadPage(rr.m_Page,m_stackTop))

+				return FALSE;

+			if(!m_stackTop.GetSize()){

+				ASSERT(m_btStack.GetSize()==1);

+				return FALSE;

+			}

+			rr.m_Offset = 0;

+			if(m_stackTop[rr.m_Offset].m_ptrLeft<0)

+				return TRUE;

+			m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset].m_ptrLeft,-1));

+		}

+	}

+	BOOL GoLast() {

+		if(!IsOpened())

+			return FALSE;

+		ASSERT(m_BTCrap->m_bRootSet);

+		m_btStack.RemoveAll();

+		m_btStack.Add(CBTRecordRef(m_BTCrap->m_Root,-1));

+		for(;;){

+		CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+			if(!LoadPage(rr.m_Page,m_stackTop))

+				return FALSE;

+			if(!m_stackTop.GetSize()){

+				ASSERT(m_btStack.GetSize()==1);

+				return FALSE;

+			}

+			rr.m_Offset = m_stackTop.GetUpperBound();

+			if(m_stackTop[rr.m_Offset].m_ptrRight<0)

+				return TRUE;

+			m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset++].m_ptrRight,-1));

+		}

+	}

+	BOOL GoNext() {

+		if(!IsOpened())

+			return FALSE;

+		if(!(m_btStack.GetSize() && m_btStack[m_btStack.GetUpperBound()].m_Offset>=0))

+			return FALSE;

+	CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+		if(!LoadPage(rr.m_Page,m_stackTop))

+			return FALSE;

+		ASSERT(rr.m_Offset<m_stackTop.GetSize());

+		if(m_stackTop[rr.m_Offset].m_ptrRight>=0){

+			// Advance pointer in this page and dive into subtree

+			// going left and left until we have nowhere to go.

+//			TRACE1("Dive into page %lu",m_stackTop[rr.m_Offset].m_ptrRight);

+			m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset++].m_ptrRight,0));

+			for(;;){

+			CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+				ASSERT(rr.m_Offset==0);

+				if(!LoadPage(rr.m_Page,m_stackTop))

+					return FALSE;

+				if(m_stackTop[rr.m_Offset].m_ptrLeft<0)

+					break;

+//				TRACE1(", %lu",m_stackTop[rr.m_Offset].m_ptrLeft);

+				m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset].m_ptrLeft,0));

+			}

+//			TRACE0("\n");

+			return TRUE;

+		}else if(rr.m_Offset<m_stackTop.GetUpperBound()){

+			rr.m_Offset++;

+			return TRUE;

+		}

+		// We're at the end of page go up until we're done or we have data.

+		m_btStack.RemoveAt(m_btStack.GetUpperBound());

+//		TRACE0("Go up");

+		while(m_btStack.GetSize()){

+		CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+			if(!LoadPage(rr.m_Page,m_stackTop))

+				return FALSE;

+			if(rr.m_Offset<m_stackTop.GetSize()){

+//				TRACE0("\n");

+				return TRUE;

+			}

+//			TRACE0(", up");

+			m_btStack.RemoveAt(m_btStack.GetUpperBound());

+		}

+//		TRACE0("\nBtree is done\n");

+		return FALSE;

+	}

+	BOOL GoPrev() {

+		if(!IsOpened())

+			return FALSE;

+		if(!(m_btStack.GetSize() && m_btStack[m_btStack.GetUpperBound()].m_Offset>=0))

+			return FALSE;

+	CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+		if(!LoadPage(rr.m_Page,m_stackTop))

+			return FALSE;

+		ASSERT(rr.m_Offset<m_stackTop.GetSize());

+		if(m_stackTop[rr.m_Offset].m_ptrLeft>=0){

+			// Dive in and go right and right from the rightmost until

+			// we have nowhere to go.

+			m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset].m_ptrLeft,-1));

+			for(;;){

+			CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+				if(!LoadPage(rr.m_Page,m_stackTop))

+					return FALSE;

+				rr.m_Offset = m_stackTop.GetUpperBound();

+				if(m_stackTop[rr.m_Offset].m_ptrRight<0)

+					return TRUE;

+				m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset++].m_ptrRight,-1));

+			}

+			return TRUE;

+		}else if(rr.m_Offset>0){

+			rr.m_Offset--;

+			return TRUE;

+		}

+		// We're at the leftmost element in page - go up and left until we're

+		// done or we have data.

+		m_btStack.RemoveAt(m_btStack.GetUpperBound());

+		while(m_btStack.GetSize()){

+		CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+			if(!LoadPage(rr.m_Page,m_stackTop))

+				return FALSE;

+			rr.m_Offset--;

+			if(rr.m_Offset>=0)

+				return TRUE;

+			m_btStack.RemoveAt(m_btStack.GetUpperBound());

+		}

+		// No more data - we were at the first element in tree.

+		return FALSE;

+	}

+	BOOL GetThis(key& _key,value& _value) {

+		if(!IsOpened())

+			return FALSE;

+		// *** MORE CHECKING

+	CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+		if(!LoadPage(rr.m_Page,m_stackTop))

+			return FALSE;

+		_key = m_stackTop[rr.m_Offset].m_Key;

+		_value = m_stackTop[rr.m_Offset].m_Value;

+		return TRUE;

+	}

+

+	BOOL SeekToPage(const key& _key) {

+		ASSERT(IsOpened());

+		ASSERT(m_BTCrap->m_bRootSet);

+		m_btStack.RemoveAll();

+		m_btStack.Add(CBTRecordRef(m_BTCrap->m_Root,-1));

+		for(;;){

+		CBTRecordRef& rr = m_btStack[m_btStack.GetUpperBound()];

+			if(!LoadPage(rr.m_Page,m_stackTop))

+				return FALSE;

+			ASSERT(m_stackTop.GetSize() || !m_btStack.GetUpperBound());

+			if(!m_stackTop.GetSize()){

+				rr.m_Offset=-1;

+				return TRUE;

+			}

+			for(rr.m_Offset=0;rr.m_Offset<m_stackTop.GetSize();rr.m_Offset++){

+				if(_key == m_stackTop[rr.m_Offset].m_Key)

+					return TRUE;

+				if(_key < m_stackTop[rr.m_Offset].m_Key){

+					ASSERT(rr.m_Offset==0 || m_stackTop[rr.m_Offset].m_ptrLeft==m_stackTop[rr.m_Offset-1].m_ptrRight);

+					if(m_stackTop[rr.m_Offset].m_ptrLeft<0)

+						return TRUE;

+					m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset].m_ptrLeft,-1));

+					break;

+				}

+				if(rr.m_Offset==m_stackTop.GetUpperBound()){

+					if(m_stackTop[rr.m_Offset].m_ptrRight<0){

+						rr.m_Offset=-1;

+						return TRUE;

+					}

+					m_btStack.Add(CBTRecordRef(m_stackTop[rr.m_Offset].m_ptrRight,-1));

+					break;

+				}

+			}

+		}

+	}

+

+	BOOL LoadPage(CBTPageRef ref,CBTPage& page) {

+	CFile* pageFile = m_BT.OpenFile(ref);

+		if(!pageFile)

+			return FALSE;

+	BOOL rv = TRUE;

+		try{

+		CArchive ar(pageFile,CArchive::load);

+			page.Serialize(ar);

+			if(m_bRO)

+				page.FreeExtra();	// ** ???

+			ar.Close();

+		}catch(CException* e){

+			e->Delete();

+			rv = FALSE;

+		}

+		delete pageFile;

+		return rv;

+	}

+	BOOL SavePage(CBTPageRef ref,CBTPage& page) {

+	CFile* pageFile = m_BT.OpenFile(ref);

+		if(!pageFile)

+			return FALSE;

+	BOOL rv = TRUE;

+		try{

+		CArchive ar(pageFile,CArchive::store);

+			page.Serialize(ar);

+			ar.Close();

+		}catch(CException* e){

+			e->Delete();

+			rv = FALSE;

+		}

+		delete pageFile;

+		return rv;

+	}

+	CBTPageRef AllocatePage() {

+	CBTDynaFile* pageFile = m_BT.CreateFile();

+		if(!pageFile)

+			return -1;

+	CBTPage nothing;

+	CBTPageRef rv = pageFile->GetFile();

+		try{

+		CArchive ar(pageFile,CArchive::store);

+			nothing.Serialize(ar);

+			ar.Close();

+		}catch(CException* e){

+			e->Delete();

+			rv = -1;

+		}

+		delete pageFile;

+		return rv;

+	}

+	BOOL DeallocatePage(CBTPageRef ref) {

+		return m_BT.DeleteFile(ref);

+	}

+

+};

+

+};

+

+#endif	// __BTREENDEX_H